,transcriber's notes3 7#a7 ,numbers following letters 7without space7 like ,c#b were originally printed in subscript4 ,letter subscripts are preceded by an underscore1 like ,cn4 7#b7 ,characters following a carat 77 were printed in superscript4 7#c7 ,side-notes were relocated to function as titles of their respective paragraphs4 7#d7 ,macrons and breves above letters and dots below letters were not inserted4 7#e7 root stands for the root symbol2 alpha1 beta1 etc4 for greek letters4 7#f7 ,the following typographical errors have been corrected3 ,,article ,,hydromechanics3 444 and omega the angular velocity about it generated by an impulse couple ,m1 and ,m' is the couple required to set the surrounding medium in motion 444 'impulse' amended from 'impluse'4 ,,article ,,hymenoptera3 444 see ,p4 ,cameron's ,british ,phytophagous ,hymenoptera 7#d vols41 ,london1 ,roy4 ,soc41 #ahhb-ahic74 ',roy' amended from ',ray'4 ,,article ,,hyrcanus3 ,during its later years his reign was much disturbed1 however1 by the contentions for ascendancy which arose between the ,pharisees and ,sadducees1 the two rival sects or parties which then for the first time 7under those names at least7 came into prominence4 'disturbed' amended from 'distrubed'4 ,,article ,,iceland3 ,iceland is emphatically a land of proverbs1 while of folk-tales1 those other keys to the people's heart1 there is plentiful store4 'people's' amended from 'poeple's'4 ,,encyclopaedia ,,britannica ,a ,,dictionary ,,of ,,arts1 ,,sciences1 ,,literature ,,and ,,general ,,information ,,eleventh ,,edition ,,volume ,,xiv1 ,,slice ,,ii ,hydromechanics to ,ichnography ,,articles ,,in ,,this ,,slice3 ,,hydromechanics ,,hythe ,,hydromedusae ,i ,,hydrometer ,,iambic ,,hydropathy ,,iamblichus 7,greek philosopher7 ,,hydrophobia ,,iamblichus 7,greek romance writer7 ,,hydrosphere ,,iannina ,,hydrostatics ,,iapetus ,,hydroxylamine ,,iapydes ,,hydrozoa ,,iatrochemistry ,,hyena ,,iazyges ,,hy,,res ,,ibadan ,,hygieia ,,ibagu ,,hygiene ,,ibarra ,,hyginus 7eighth pope7 ,,iberians ,,hyginus 7,latin writer7 ,,ibex ,,hyginus1 ,,gaius ,,julius ,,ibis ,,hygrometer ,,iblis ,,hyksos ,,ibn ',,abd ,,rabbihi ,,hylas ,,ibn ',,arabi ,,hylozoism ,,ibn ,,athir ,,hymen ,,ibn ,,batuta ,,hymenoptera ,,ibn ,,duraid ,,hymettus ,,ibn ,,faradi ,,hymns ,,ibn ,,farid ,,hypaethros ,,ibn ,,gabirol ,,hypallage ,,ibn ,,haukal ,,hypatia ,,ibn ,,hazm ,,hyperbaton ,,ibn ,,hisham ,,hyperbola ,,ibn ,,ishaq ,,hyperbole ,,ibn ,,jubair ,,hyperboreans ,,ibn ,,khaldun ,,hypereides ,,ibn ,,khallikan ,,hyperion ,,ibn ,,qutaiba ,,hypersthene ,,ibn ,,sa',d ,,hypertrophy ,,ibn ,,tibbon ,,hypnotism ,,ibn ,,tufail ,,hypocaust ,,ibn ,,usaibi',a ,,hypochondriasis ,,ibo ,,hypocrisy ,,ibrahim ,,al-,,mausili ,,hypostasis ,,ibrahim ,,pasha ,,hypostyle ,,ibsen1 ,,henrik ,,hyposulphite ,,of ,,soda ,,ibycus ,,hypothec ,,ica ,,hypothesis ,,ice ,,hypotrachelium ,,iceberg ,,hypsometer ,,iceland ,,hyracoidea ,,iceland ,,moss ,,hyrcania ,,ice-,,plant ,,hyrcanus ,,ice-,,yachting ,,hyssop ,i-,,ch',,ang ,,hystaspes ,,ichneumon ,,hysteresis ,,ichneumon-,,fly ,,hysteria ,,ichnography ,,hysteron-,,proteron ,,hydromechanics 7,greek3 hydromchanika71 the science of the mechanics of water and fluids in general1 including hydrostatics or the mathematical theory of fluids in equilibrium1 and hydromechanics1 the theory of fluids in motion4 ,the practical application of hydromechanics forms the province of hydraulics 7q4v474 ,historical4--,the fundamental principles of hydrostatics were first given by ,archimedes in his work ,greek3 ,peri tn ochoumenn1 or ,de iis quae vehuntur in humido1 about #bej ,b4,c41 and were afterwards applied to experiments by ,marino ,ghetaldi 7#aeff-afbg7 in his ,promotus ,archimedes 7#afjc74 ,archimedes maintained that each particle of a fluid mass1 when in equilibrium1 is equally pressed in every direction2 and he inquired into the conditions according to which a solid body floating in a fluid should assume and preserve a position of equilibrium4 ,in the ,greek school at ,alexandria1 which flourished under the auspices of the ,ptolemies1 the first attempts were made at the construction of hydraulic machinery1 and about #abj ,b4,c4 the fountain of compression1 the siphon1 and the forcing-pump were invented by ,ctesibius and ,hero4 ,the siphon is a simple instrument2 but the forcing-pump is a complicated invention1 which could scarcely have been expected in the infancy of hydraulics4 ,it was probably suggested to ,ctesibius by the ,egyptian ,wheel or ,noria1 which was common at that time1 and which was a kind of chain pump1 consisting of a number of earthen pots carried round by a wheel4 ,in some of these machines the pots have a valve in the bottom which enables them to descend without much resistance1 and diminishes greatly the load upon the wheel2 and1 if we suppose that this valve was introduced so early as the time of ,ctesibius1 it is not difficult to perceive how such a machine might have led to the invention of the forcing-pump4 ,notwithstanding these inventions of the ,alexandrian school1 its attention does not seem to have been directed to the motion of fluids2 and the first attempt to investigate this subject was made by ,sextus ,julius ,frontinus1 inspector of the public fountains at ,rome in the reigns of ,nerva and ,trajan4 ,in his work ,de aquaeductibus urbis ,romae commentarius1 he considers the methods which were at that time employed for ascertaining the quantity of water discharged from ajutages1 and the mode of distributing the waters of an aqueduct or a fountain4 ,he remarked that the flow of water from an orifice depends not only on the magnitude of the orifice itself1 but also on the height of the water in the reservoir2 and that a pipe employed to carry off a portion of water from an aqueduct should1 as circumstances required1 have a position more or less inclined to the original direction of the current4 ,but as he was unacquainted with the law of the velocities of running water as depending upon the depth of the orifice1 the want of precision which appears in his results is not surprising4 ,benedetto ,castelli 7#aegg-afdd71 and ,evangelista ,torricelli 7#afjh-afdg71 two of the disciples of ,galileo1 applied the discoveries of their master to the science of hydrodynamics4 ,in #afbh ,castelli published a small work1 ,della misura dell' acque correnti1 in which he satisfactorily explained several phenomena in the motion of fluids in rivers and canals2 but he committed a great paralogism in supposing the velocity of the water proportional to the depth of the orifice below the surface of the vessel4 ,torricelli1 observing that in a jet where the water rushed through a small ajutage it rose to nearly the same height with the reservoir from which it was supplied1 imagined that it ought to move with the same velocity as if it had fallen through that height by the force of gravity1 and hence he deduced the proposition that the velocities of liquids are as the square root of the head1 apart from the resistance of the air and the friction of the orifice4 ,this theorem was published in #afdc1 at the end of his treatise ,de motu gravium projectorum1 and it was confirmed by the experiments of ,raffaello ,magiotti on the quantities of water discharged from different ajutages under different pressures 7#afdh74 ,in the hands of ,blaise ,pascal 7#afbc-affb7 hydrostatics assumed the dignity of a science1 and in a treatise on the equilibrium of liquids 7,sur l'quilibre des liqueurs71 found among his manuscripts after his death and published in #affc1 the laws of the equilibrium of liquids were demonstrated in the most simple manner1 and amply confirmed by experiments4 ,the theorem of ,torricelli was employed by many succeeding writers1 but particularly by ,edm ,mariotte 7#afbj-afhd71 whose ,trait du mouvement des eaux1 published after his death in the year #afhf1 is founded on a great variety of well-conducted experiments on the motion of fluids1 performed at ,versailles and ,chantilly4 ,in the discussion of some points he committed considerable mistakes4 ,others he treated very superficially1 and in none of his experiments apparently did he attend to the diminution of efflux arising from the contraction of the liquid vein1 when the orifice is merely a perforation in a thin plate2 but he appears to have been the first who attempted to ascribe the discrepancy between theory and experiment to the retardation of the water's velocity through friction4 ,his contemporary ,domenico ,guglielmini 7#afee-agaj71 who was inspector of the rivers and canals at ,bologna1 had ascribed this diminution of velocity in rivers to transverse motions arising from inequalities in their bottom4 ,but as ,mariotte observed similar obstructions even in glass pipes where no transverse currents could exist1 the cause assigned by ,guglielmini seemed destitute of foundation4 ,the ,french philosopher1 therefore1 regarded these obstructions as the effects of friction4 ,he supposed that the filaments of water which graze along the sides of the pipe lose a portion of their velocity2 that the contiguous filaments1 having on this account a greater velocity1 rub upon the former1 and suffer a diminution of their celerity2 and that the other filaments are affected with similar retardations proportional to their distance from the axis of the pipe4 ,in this way the medium velocity of the current may be diminished1 and consequently the quantity of water discharged in a given time must1 from the effects of friction1 be considerably less than that which is computed from theory4 ,the effects of friction and viscosity in diminishing the velocity of running water were noticed in the ,principia of ,sir ,isaac ,newton1 who threw much light upon several branches of hydromechanics4 ,at a time when the ,cartesian system of vortices universally prevailed1 he found it necessary to investigate that hypothesis1 and in the course of his investigations he showed that the velocity of any stratum of the vortex is an arithmetical mean between the velocities of the strata which enclose it2 and from this it evidently follows that the velocity of a filament of water moving in a pipe is an arithmetical mean between the velocities of the filaments which surround it4 ,taking advantage of these results1 ,henri ,pitot 7#afie-agga7 afterwards showed that the retardations arising from friction are inversely as the diameters of the pipes in which the fluid moves4 ,the attention of ,newton was also directed to the discharge of water from orifices in the bottom of vessels4 ,he supposed a cylindrical vessel full of water to be perforated in its bottom with a small hole by which the water escaped1 and the vessel to be supplied with water in such a manner that it always remained full at the same height4 ,he then supposed this cylindrical column of water to be divided into two parts1--the first1 which he called the cataract1 being an hyperboloid generated by the revolution of an hyperbola of the fifth degree around the axis of the cylinder which should pass through the orifice1 and the second the remainder of the water in the cylindrical vessel4 ,he considered the horizontal strata of this hyperboloid as always in motion1 while the remainder of the water was in a state of rest1 and imagined that there was a kind of cataract in the middle of the fluid4 ,when the results of this theory were compared with the quantity of water actually discharged1 ,newton concluded that the velocity with which the water issued from the orifice was equal to that which a falling body would receive by descending through half the height of water in the reservoir4 ,this conclusion1 however1 is absolutely irreconcilable with the known fact that jets of water rise nearly to the same height as their reservoirs1 and ,newton seems to have been aware of this objection4 ,accordingly1 in the second edition of his ,principia1 which appeared in #agac1 he reconsidered his theory4 ,he had discovered a contraction in the vein of fluid 7vena contracta7 which issued from the orifice1 and found that1 at the distance of about a diameter of the aperture1 the section of the vein was contracted in the subduplicate ratio of two to one4 ,he regarded1 therefore1 the section of the contracted vein as the true orifice from which the discharge of water ought to be deduced1 and the velocity of the effluent water as due to the whole height of water in the reservoir2 and by this means his theory became more conformable to the results of experience1 though still open to serious objections4 ,newton was also the first to investigate the difficult subject of the motion of waves 7q4v474 ,in #agch ,daniel ,bernoulli 7#agjj-aghb7 published his ,hydrodynamica seu de viribus et motibus fluidorum commentarii4 ,his theory of the motion of fluids1 the germ of which was first published in his memoir entitled ,theoria nova de motu aquarum per canales quocunque fluentes1 communicated to the ,academy of ,st ,petersburg as early as #agbf1 was founded on two suppositions1 which appeared to him conformable to experience4 ,he supposed that the surface of the fluid1 contained in a vessel which is emptying itself by an orifice1 remains always horizontal2 and1 if the fluid mass is conceived to be divided into an infinite number of horizontal strata of the same bulk1 that these strata remain contiguous to each other1 and that all their points descend vertically1 with velocities inversely proportional to their breadth1 or to the horizontal sections of the reservoir4 ,in order to determine the motion of each stratum1 he employed the principle of the conservatio virium vivarum1 and obtained very elegant solutions4 ,but in the absence of a general demonstration of that principle1 his results did not command the confidence which they would otherwise have deserved1 and it became desirable to have a theory more certain1 and depending solely on the fundamental laws of mechanics4 ,colin ,maclaurin 7#afih-agdf7 and ,john ,bernoulli 7#affg-agdh71 who were of this opinion1 resolved the problem by more direct methods1 the one in his ,fluxions1 published in #agdb1 and the other in his ,hydraulica nunc primum detecta1 et demonstrata directe ex fundamentis pure mechanicis1 which forms the fourth volume of his works4 ,the method employed by ,maclaurin has been thought not sufficiently rigorous2 and that of ,john ,bernoulli is1 in the opinion of ,lagrange1 defective in clearness and precision4 ,the theory of ,daniel ,bernoulli was opposed also by ,jean le ,rond d',alembert4 ,when generalizing the theory of pendulums of ,jacob ,bernoulli 7#afed-agje7 he discovered a principle of dynamics so simple and general that it reduced the laws of the motions of bodies to that of their equilibrium4 ,he applied this principle to the motion of fluids1 and gave a specimen of its application at the end of his ,dynamics in #agdc4 ,it was more fully developed in his ,trait des fluides1 published in #agdd1 in which he gave simple and elegant solutions of problems relating to the equilibrium and motion of fluids4 ,he made use of the same suppositions as ,daniel ,bernoulli1 though his calculus was established in a very different manner4 ,he considered1 at every instant1 the actual motion of a stratum as composed of a motion which it had in the preceding instant and of a motion which it had lost2 and the laws of equilibrium between the motions lost furnished him with equations representing the motion of the fluid4 ,it remained a desideratum to express by equations the motion of a particle of the fluid in any assigned direction4 ,these equations were found by d',alembert from two principles--that a rectangular canal1 taken in a mass of fluid in equilibrium1 is itself in equilibrium1 and that a portion of the fluid1 in passing from one place to another1 preserves the same volume when the fluid is incompressible1 or dilates itself according to a given law when the fluid is elastic4 ,his ingenious method1 published in #ageb1 in his ,essai sur la rsistance des fluides1 was brought to perfection in his ,opuscules mathmatiques1 and was adopted by ,leonhard ,euler4 ,the resolution of the questions concerning the motion of fluids was effected by means of ,euler's partial differential coefficients4 ,this calculus was first applied to the motion of water by d',alembert1 and enabled both him and ,euler to represent the theory of fluids in formulae restricted by no particular hypothesis4 ,one of the most successful labourers in the science of hydrodynamics at this period was ,pierre ,louis ,georges ,dubuat 7#agcd-ahji74 ,following in the steps of the ,abb ,charles ,bossut 7,nouvelles ,experiences sur la rsistance des fluides1 #aggg71 he published1 in #aghf1 a revised edition of his ,principes d'hydraulique1 which contains a satisfactory theory of the motion of fluids1 founded solely upon experiments4 ,dubuat considered that if water were a perfect fluid1 and the channels in which it flowed infinitely smooth1 its motion would be continually accelerated1 like that of bodies descending in an inclined plane4 ,but as the motion of rivers is not continually accelerated1 and soon arrives at a state of uniformity1 it is evident that the viscosity of the water1 and the friction of the channel in which it descends1 must equal the accelerating force4 ,dubuat1 therefore1 assumed it as a proposition of fundamental importance that1 when water flows in any channel or bed1 the accelerating force which obliges it to move is equal to the sum of all the resistances which it meets with1 whether they arise from its own viscosity or from the friction of its bed4 ,this principle was employed by him in the first edition of his work1 which appeared in #aggi4 ,the theory contained in that edition was founded on the experiments of others1 but he soon saw that a theory so new1 and leading to results so different from the ordinary theory1 should be founded on new experiments more direct than the former1 and he was employed in the performance of these from #aghj to #aghc4 ,the experiments of ,bossut were made only on pipes of a moderate declivity1 but ,dubuat used declivities of every kind1 and made his experiments upon channels of various sizes4 ,the theory of running water was greatly advanced by the researches of ,gaspard ,riche de ,prony 7#agee-ahci74 ,from a collection of the best experiments by previous workers he selected eighty-two 7fifty-one on the velocity of water in conduit pipes1 and thirty-one on its velocity in open canals72 and1 discussing these on physical and mechanical principles1 he succeeded in drawing up general formulae1 which afforded a simple expression for the velocity of running water4 ,j4 ,a4 ,eytelwein 7#agfd-ahdh7 of ,berlin1 who published in #ahja a valuable compendium of hydraulics entitled ,handbuch der ,mechanik und der ,hydraulik1 investigated the subject of the discharge of water by compound pipes1 the motions of jets and their impulses against plane and oblique surfaces2 and he showed theoretically that a water-wheel will have its maximum effect when its circumference moves with half the velocity of the stream4 ,j4 ,n4 ,p4 ,hachette 7#agfi-ahcd7 in #ahaf-ahag published memoirs containing the results of experiments on the spouting of fluids and the discharge of vessels4 ,his object was to measure the contracted part of a fluid vein1 to examine the phenomena attendant on additional tubes1 and to investigate the form of the fluid vein and the results obtained when different forms of orifices are employed4 ,extensive experiments on the discharge of water from orifices 7,expriences hydrauliques1 ,paris1 #ahcb7 were conducted under the direction of the ,french government by ,j4 ,v4 ,poncelet 7#aghh-ahfg7 and ,j4 ,a4 ,lesbros 7#agij-ahfj74 ,p4 ,p4 ,boileau 7#ahaa-ahia7 discussed their results and added experiments of his own 7,trait de la msure des eaux courantes1 ,paris1 #ahed74 ,k4 ,r4 ,bornemann re-examined all these results with great care1 and gave formulae expressing the variation of the coefficients of discharge in different conditions 7,civil ,ingnieur1 #ahhj74 ,julius ,weisbach 7#ahjf-ahga7 also made many experimental investigations on the discharge of fluids4 ,the experiments of ,j4 ,b4 ,francis 7,lowell ,hydraulic ,experiments1 ,boston1 ,mass41 #ahee7 led him to propose variations in the accepted formulae for the discharge over weirs1 and a generation later a very complete investigation of this subject was carried out by ,h4 ,bazin4 ,an elaborate inquiry on the flow of water in pipes and channels was conducted by ,h4 ,g4 ,p4 ,darcy 7#ahjc-aheh7 and continued by ,h4 ,bazin1 at the expense of the ,french government 7,recherches hydrauliques1 ,paris1 #ahff74 ,german engineers have also devoted special attention to the measurement of the flow in rivers2 the ,beitrge zur ,hydrographie des ,knigreiches ,bhmen 7,prague1 #ahgb-ahge7 of ,a4 ,r4 ,harlacher 7#ahdb-ahij7 contained valuable measurements of this kind1 together with a comparison of the experimental results with the formulae of flow that had been proposed up to the date of its publication1 and important data were yielded by the gaugings of the ,mississippi made for the ,united ,states government by ,a4 ,a4 ,humphreys and ,h4 ,l4 ,abbot1 by ,robert ,gordon's gaugings of the ,irrawaddy1 and by ,allen ,j4 ,c4 ,cunningham's experiments on the ,ganges canal4 ,the friction of water1 investigated for slow speeds by ,coulomb1 was measured for higher speeds by ,william ,froude 7#ahaj-ahgi71 whose work is of great value in the theory of ship resistance 7,brit4 ,assoc4 ,report41 #ahfi71 and stream line motion was studied by ,professor ,osborne ,reynolds and by ,professor ,h4 ,s4 ,hele ,shaw4 7,x47 ,,hydrostatics ,hydrostatics is a science which grew originally out of a number of isolated practical problems2 but it satisfies the requirement of perfect accuracy in its application to phenomena1 the largest and smallest1 of the behaviour of a fluid4 ,at the same time1 it delights the pure theorist by the simplicity of the logic with which the fundamental theorems may be established1 and by the elegance of its mathematical operations1 insomuch that hydrostatics may be considered as the ,euclidean pure geometry of mechanical science4 #a4 ,the ,different ,states of a ,substance or ,matter4--,all substance in nature falls into one of the two classes1 solid and fluid2 a solid substance1 the land1 for instance1 as contrasted with a fluid1 like water1 being a substance which does not flow of itself4 ,a fluid1 as the name implies1 is a substance which flows1 or is capable of flowing2 water and air are the two fluids distributed most universally over the surface of the earth4 ,fluids again are divided into two classes1 termed a liquid and a gas1 of which water and air are the chief examples4 ,a liquid is a fluid which is incompressible or practically so1 i4e4 it does not change in volume sensibly with change of pressure4 ,a gas is a compressible fluid1 and the change in volume is considerable with moderate variation of pressure4 ,liquids1 again1 can be poured from one open vessel into another1 and can be kept in an uncovered vessel1 but a gas tends to diffuse itself indefinitely and must be preserved in a closed reservoir4 ,the distinguishing characteristics of the three kinds of substance or states of matter1 the solid1 liquid and gas1 are summarized thus in ,o4 ,lodge's ,mechanics3-- ,a solid has both size and shape4 ,a liquid has size but not shape4 ,a gas has neither size nor shape4 #b4 ,the ,change of ,state of ,matter4--,by a change of temperature and pressure combined1 a substance can in general be made to pass from one state into another2 thus by gradually increasing the temperature a solid piece of ice can be melted into the liquid state of water1 and the water again can be boiled off into the gaseous state as steam4 ,again1 by raising the temperature1 a metal in the solid state can be melted and liquefied1 and poured into a mould to assume any form desired1 which is retained when the metal cools and solidifies again2 the gaseous state of a metal is revealed by the spectroscope4 ,conversely1 a combination of increased pressure and lowering of temperature will1 if carried far enough1 reduce a gas to a liquid1 and afterwards to the solid state2 and nearly every gaseous substance has now undergone this operation4 ,a certain critical temperature is observed in a gas1 above which the liquefaction is impossible2 so that the gaseous state has two subdivisions into 7i47 a true gas1 which cannot be liquefied1 because its temperature is above the critical temperature1 7ii47 a vapour1 where the temperature is below the critical1 and which can ultimately be liquefied by further lowering of temperature or increase of pressure4 #c4 ,plasticity and ,viscosity4--,every solid substance is found to be plastic more or less1 as exemplified by punching1 shearing and cutting2 but the plastic solid is distinguished from the viscous fluid in that a plastic solid requires a certain magnitude of stress to be exceeded to make it flow1 whereas the viscous liquid will yield to the slightest stress1 but requires a certain length of time for the effect to be appreciable4 ,according to ,maxwell 7,theory of ,heat7 ,when a continuous alteration of form is produced only by a stress exceeding a certain value1 the substance is called a solid1 however soft and plastic it may be4 ,but when the smallest stress1 if only continued long enough1 will cause a perceptible and increasing change of form1 the substance must be regarded as a viscous fluid1 however hard it may be4 ,maxwell illustrates the difference between a soft solid and a hard liquid by a jelly and a block of pitch2 also by the experiment of supporting a candle and a stick of sealing-wax2 after a considerable time the sealing-wax will be found bent and so is a fluid1 but the candle remains straight as a solid4 #d4 ,definition of a ,fluid4--,a fluid is a substance which yields continually to the slightest tangential stress in its interior2 that is1 it can be divided very easily along any plane 7given plenty of time if the fluid is viscous74 ,it follows that when the fluid has come to rest1 the tangential stress in any plane in its interior must vanish1 and the stress must be entirely normal to the plane4 ,this mechanical axiom of the normality of fluid pressure is the foundation of the mathematical theory of hydrostatics4 ,the theorems of hydrostatics are thus true for all stationary fluids1 however viscous they may be2 it is only when we come to hydrodynamics1 the science of the motion of a fluid1 that viscosity will make itself felt and modify the theory2 unless we begin by postulating the perfect fluid1 devoid of viscosity1 so that the principle of the normality of fluid pressure is taken to hold when the fluid is in movement4 #e4 ,the ,measurement of ,fluid ,pressure4--,the pressure at any point of a plane in the interior of a fluid is the intensity of the normal thrust estimated per unit area of the plane4 ,thus1 if a thrust of ,p lb4 is distributed uniformly over a plane area of ,a sq4 ft41 as on the horizontal bottom of the sea or any reservoir1 the pressure at any point of the plane is ,p_/,a lb4 per sq4 ft41 or ,p_/#add;,a lb4 per sq4 in4 7lb4_/ft4 and lb4_/in41 in the ,hospitalier notation1 to be employed in the sequel74 ,if the distribution of the thrust is not uniform1 as1 for instance1 on a vertical or inclined face or wall of a reservoir1 then ,p_/,a represents the average pressure over the area2 and the actual pressure at any point is the average pressure over a small area enclosing the point4 ,thus1 if a thrust ,delta,p lb4 acts on a small plane area ,delta,a ft4 enclosing a point ,b1 the pressure p at ,b is the limit of ,delta,p_/,delta,a2 and p lt7,delta,p_/,delta,a7 d,p_/d,a1 7#a7 in the notation of the differential calculus4 #f4 ,the ,equality of ,fluid ,pressure in all ,directions4--,this fundamental principle of hydrostatics follows at once from the principle of the normality of fluid pressure implied in the definition of a fluid in #d4 ,take any two arbitrary directions in the plane of the paper1 and draw a small isosceles triangle abc1 whose sides are perpendicular to the two directions1 and consider the equilibrium of a small triangular prism of fluid1 of which the triangle is the cross section4 ,let ,p1 ,q denote the normal thrust across the sides bc1 ca1 and ,r the normal thrust across the base ab4 ,then1 since these three forces maintain equilibrium1 and ,r makes equal angles with ,p and ,q1 therefore ,p and ,q must be equal4 ,but the faces bc1 ca1 over which ,p and ,q act1 are also equal1 so that the pressure on each face is equal4 ,a scalene triangle abc might also be employed1 or a tetrahedron4 ,illustration3 ,,fig4 #a;a4 ,it follows that the pressure of a fluid requires to be calculated in one direction only1 chosen as the simplest direction for convenience4 #g4 ,the ,transmissibility of ,fluid ,pressure4--,any additional pressure applied to the fluid will be transmitted equally to every point in the case of a liquid2 this principle of the transmissibility of pressure was enunciated by ,pascal1 #afec1 and applied by him to the invention of the hydraulic press4 ,this machine consists essentially of two communicating cylinders 7fig4 #a;a71 filled with liquid and closed by pistons4 ,if a thrust ,p lb4 is applied to one piston of area ,a ft41 it will be balanced by a thrust ,w lb4 applied to the other piston of area ,b ft41 where p ,p_/,a ,w_/,b1 7#a7 the pressure p of the liquid being supposed uniform2 and1 by making the ratio ,b_/,a sufficiently large1 the mechanical advantage can be increased to any desired amount1 and in the simplest manner possible1 without the intervention of levers and machinery4 ,fig4 #a;b shows also a modern form of the hydraulic press1 applied to the operation of covering an electric cable with a lead coating4 #h4 ,theorem4--,in a fluid at rest under gravity the pressure is the same at any two points in the same horizontal plane2 in other words1 a surface of equal pressure is a horizontal plane4 ,this is proved by taking any two points ,a and ,b at the same level1 and considering the equilibrium of a thin prism of liquid ,,ab1 bounded by planes at ,a and ,b perpendicular to ,,ab4 ,as gravity and the fluid pressure on the sides of the prism act at right angles to ,,ab1 the equilibrium requires the equality of thrust on the ends ,a and ,b2 and as the areas are equal1 the pressure must be equal at ,a and ,b2 and so the pressure is the same at all points in the same horizontal plane4 ,if the fluid is a liquid1 it can have a free surface without diffusing itself1 as a gas would2 and this free surface1 being a surface of zero pressure1 or more generally of uniform atmospheric pressure1 will also be a surface of equal pressure1 and therefore a horizontal plane4 ,illustration3 ,,fig4 #a;b4 ,hence the theorem4--,the free surface of a liquid at rest under gravity is a horizontal plane4 ,this is the characteristic distinguishing between a solid and a liquid2 as1 for instance1 between land and water4 ,the land has hills and valleys1 but the surface of water at rest is a horizontal plane2 and if disturbed the surface moves in waves4 #i4 ,theorem4--,in a homogeneous liquid at rest under gravity the pressure increases uniformly with the depth4 ,this is proved by taking the two points ,a and ,b in the same vertical line1 and considering the equilibrium of the prism by resolving vertically4 ,in this case the thrust at the lower end ,b must exceed the thrust at ,a1 the upper end1 by the weight of the prism of liquid2 so that1 denoting the cross section of the prism by alpha ft41 the pressure at ,a and ,by by p#j and p lb4_/ft41 and by w the density of the liquid estimated in lb4_/ft41 palpha - p#j;alpha walpha,,ab1 7#a7 p w,,ab p#j4 7#b7 ,thus in water1 where w #fb4dlb4_/ft41 the pressure increases #fb4d lb4_/ft41 or #fb4d #add #j4dcc lb4_/in4 for every additional foot of depth4 #aj4 ,theorem4--,if two liquids of different density are resting in vessels in communication1 the height of the free surface of such liquid above the surface of separation is inversely as the density4 ,for if the liquid of density sigma rises to the height h and of density rho to the height k1 and p#j denotes the atmospheric pressure1 the pressure in the liquid at the level of the surface of separation will be sigmah p#j and rhok p#j1 and these being equal we have sigmah rhok4 7#a7 ,the principle is illustrated in the article ,,barometer1 where a column of mercury of density sigma and height h1 rising in the tube to the ,torricellian vacuum1 is balanced by a column of air of density rho1 which may be supposed to rise as a homogeneous fluid to a height k1 called the height of the homogeneous atmosphere4 ,thus water being about #hjj times denser than air and mercury #ac4f times denser than water1 k_/h sigma_/rho #hjj #ac4f #aj1hhj2 7#b7 and with an average barometer height of #cj in4 this makes k #bg1bjj ft41 about #hcjj metres4 #aa4 ,the ,head of ,water or a ,liquid4--,the pressure sigmah at a depth h ft4 in liquid of density sigma is called the pressure due to a head of h ft4 of the liquid4 ,the atmospheric pressure is thus due to an average head of #cj in4 of mercury1 or #cj #ac4f #ab #cd ft4 of water1 or #bg1bjj ft4 of air4 ,the pressure of the air is a convenient unit to employ in practical work1 where it is called an atmosphere2 it is made the equivalent of a pressure of one kg_/cm2 and one ton_/inch1 employed as the unit with high pressure as in artillery1 may be taken as #aej atmospheres4 #ab4 ,theorem4--,a body immersed in a fluid is buoyed up by a force equal to the weight of the liquid displaced1 acting vertically upward through the centre of gravity of the displaced liquid4 ,for if the body is removed1 and replaced by the fluid as at first1 this fluid is in equilibrium under its own weight and the thrust of the surrounding fluid1 which must be equal and opposite1 and the surrounding fluid acts in the same manner when the body replaces the displaced fluid again2 so that the resultant thrust of the fluid acts vertically upward through the centre of gravity of the fluid displaced1 and is equal to the weight4 ,when the body is floating freely like a ship1 the equilibrium of this liquid thrust with the weight of the ship requires that the weight of water displaced is equal to the weight of the ship and the two centres of gravity are in the same vertical line4 ,so also a balloon begins to rise when the weight of air displaced is greater than the weight of the balloon1 and it is in equilibrium when the weights are equal4 ,this theorem is called generally the principle of ,archimedes4 ,it is used to determine the density of a body experimentally2 for if ,w is the weight of a body weighed in a balance in air 7strictly in vacuo71 and if ,w is the weight required to balance when the body is suspended in water1 then the upward thrust of the liquid or weight of liquid displaced is ,w - ,w1 so that the specific gravity 7,s4,g471 defined as the ratio of the weight of a body to the weight of an equal volume of water1 is ,w_/7,w - ,w74 ,as stated first by ,archimedes1 the principle asserts the obvious fact that a body displaces its own volume of water2 and he utilized it in the problem of the determination of the adulteration of the crown of ,hiero4 ,he weighed out a lump of gold and of silver of the same weight as the crown2 and1 immersing the three in succession in water1 he found they spilt over measures of water in the ratio #a_/ad 3 #d_/gg 3 #b_/ba or #cc 3 #bd 3 #dd2 thence it follows that the gold 3 silver alloy of the crown was as #aa 3 #i by weight4 #ac4 ,theorem4--,the resultant vertical thrust on any portion of a curved surface exposed to the pressure of a fluid at rest under gravity is the weight of fluid cut out by vertical lines drawn round the boundary of the curved surface4 ,theorem4--,the resultant horizontal thrust in any direction is obtained by drawing parallel horizontal lines round the boundary1 and intersecting a plane perpendicular to their direction in a plane curve2 and then investigating the thrust on this plane area1 which will be the same as on the curved surface4 ,the proof of these theorems proceeds as before1 employing the normality principle2 they are required1 for instance1 in the determination of the liquid thrust on any portion of the bottom of a ship4 ,in casting a thin hollow object like a bell1 it will be seen that the resultant upward thrust on the mould may be many times greater than the weight of metal2 many a curious experiment has been devised to illustrate this property and classed as a hydrostatic paradox 7,boyle1 ,hydrostatical ,paradoxes1 #afff74 ,illustration3 ,,fig4 #b4 ,consider1 for instance1 the operation of casting a hemispherical bell1 in fig4 #b4 ,as the molten metal is run in1 the upward thrust on the outside mould1 when the level has reached ,,pp1 is the weight of metal in the volume generated by the revolution of ,,apq2 and this1 by a theorem of ,archimedes1 has the same volume as the cone ,,orr1 or #a_/c piy1 where y is the depth of metal1 the horizontal sections being equal so long as y is less than the radius of the outside hemisphere4 ,afterwards1 when the metal has risen above ,b1 to the level ,,kk1 the additional thrust is the weight of the cylinder of diameter ,,kk and height ,,bh4 ,the upward thrust is the same1 however thin the metal may be in the interspace between the outer mould and the core inside2 and this was formerly considered paradoxical4 ,analytical ,equations of ,equilibrium of a ,fluid at rest under any ,system of ,force4 #ad4 ,referred to three fixed coordinate axes1 a fluid1 in which the pressure is p1 the density rho1 and ,x1 ,y1 ,z the components of impressed force per unit mass1 requires for the equilibrium of the part filling a fixed surface ,s1 on resolving parallel to ,ox1 _/ _/ _/ _/ _/ lp d,s rho,x dx dy dz1 7#a7 _/ _/ _/ _/ _/ where l1 m1 n denote the direction cosines of the normal drawn outward of the surface ,s4 ,but by ,green's transformation _/ _/ _/ _/ _/ dp lp d,s -- dx dy dz1 7#b7 _/ _/ _/ _/ _/ dx thus leading to the differential relation at every point dp dp dp -- rho,x1 -- rho,y1 -- rho,z4 7#c7 dx dy dz ,the three equations of equilibrium obtained by taking moments round the axes are then found to be satisfied identically4 ,hence the space variation of the pressure in any direction1 or the pressure-gradient1 is the resolved force per unit volume in that direction4 ,the resultant force is therefore in the direction of the steepest pressure-gradient1 and this is normal to the surface of equal pressure2 for equilibrium to exist in a fluid the lines of force must therefore be capable of being cut orthogonally by a system of surfaces1 which will be surfaces of equal pressure4 ,ignoring temperature effect1 and taking the density as a function of the pressure1 surfaces of equal pressure are also of equal density1 and the fluid is stratified by surfaces orthogonal to the lines of force2 #a dp #a dp #a dp ----- --1 ----- --1 ----- --1 or ,x1 ,y1 ,z 7#d7 rho dx rho dy rho dz are the partial differential coefficients of some function ,p1 intdp_/rho1 of x1 y1 z2 so that ,x1 ,y1 ,z must be the partial differential coefficients of a potential -,v1 such that the force in any direction is the downward gradient of ,v2 and then d,p d,v -- -- #j1 or ,p ,v constant1 7#e7 dx dx in which ,p may be called the hydrostatic head and ,v the head of potential4 ,with variation of temperature1 the surfaces of equal pressure and density need not coincide2 but1 taking the pressure1 density and temperature as connected by some relation1 such as the gas-equation1 the surfaces of equal density and temperature must intersect in lines lying on a surface of equal pressure4 #ae4 ,as an example of the general equations1 take the simplest case of a uniform field of gravity1 with ,oz directed vertically downward2 employing the gravitation unit of force1 #a dp #a dp #a dp ----- -- #j1 ----- -- #j1 ----- -- #a1 7#a7 rho dx rho dy rho dz _/ ,p dp_/rho z a constant4 7#b7 _/ ,when the density rho is uniform1 this becomes1 as before in 7#b7 #i p rhoz p#j4 7#c7 ,suppose the density rho varies as some nth power of the depth below ,o1 then dp_/dz rho muzn 7#d7 z7n#a7 rhoz rho _/rho#a_/n p mu------- ------ ----- 7 ----- 7 1 7#e7 n #a n #a n #a mu _/ supposing p and rho to vanish together4 ,these equations can be made to represent the state of convective equilibrium of the atmosphere1 depending on the gas-equation p rhok ,rrhotheta1 7#f7 where theta denotes the absolute temperature2 and then dtheta d _/ p #a ,r-------- -- 7 ----- 7 -------1 7#g7 dz dz rho_/ 7n #a7 so that the temperature-gradient dtheta_/dz is constant1 as in convective equilibrium in 7#aa74 ,from the gas-equation in general1 in the atmosphere #a dp #a dp #a dtheta rho #a dtheta #a #a dtheta ----- -- --- -- - ------- -------- ----- - ------- -------- --- - ------- --------1 7#h7 rho dz p dz theta dz p theta dz k theta dz which is positive1 and the density rho diminishes with the ascent1 provided the temperature-gradient dtheta_/dz does not exceed theta_/k4 ,with uniform temperature1 taking k constant in the gas-equation1 dp_/dz rho p_/k1 p p#j;e7z_/k71 7#i7 so that in ascending in the atmosphere of thermal equilibrium the pressure and density diminish at compound discount1 and for pressures p#a and p#b at heights z#a and z#b 7z#a - z#b7_/k log e 7p#b_/p#a7 #b4c log#aj 7p#b_/p#a74 7#aj7 ,in the convective equilibrium of the atmosphere1 the air is supposed to change in density and pressure without exchange of heat by conduction2 and then rho_/rho#j 7theta_/theta#j7n1 p_/p#j 7theta_/theta#j77n#a71 7#aa7 dz #a dp p #a -------- ----- -------- 7n #a7------------,r1 gamma #a ---1 dtheta rho dtheta rhotheta n where gamma is the ratio of the specific heat at constant pressure and constant volume4 ,in the more general case of the convective equilibrium of a spherical atmosphere surrounding the earth1 of radius a1 dp p#j dtheta a ----- 7n #a7------ -------- - --- dr1 7#ab7 rho rho#j theta#j r gravity varying inversely as the square of the distance r from the centre2 so that1 k p#j_/rho#j1 denoting the height of the homogeneous atmosphere at the surface1 theta is given by 7n #a7 k 7#a - theta_/theta#j7 a7#a - a_/r71 7#ac7 or if c denotes the distance where theta #j1 theta a c - r -------- --- -----4 7#ad7 theta#j r c - a ,when the compressibility of water is taken into account in a deep ocean1 an experimental law must be employed1 such as p - p#j k7rho - rho#j71 or rho_/rho#j #a 7p - p#j7_/lambda1 lambda krho#j1 7#ae7 so that lambda is the pressure due to a head k of the liquid at density rho#j under atmospheric pressure p#j2 and it is the gauge pressure required on this law to double the density4 ,then dp_/dz kdrho_/dz rho1 rho rho#j;e7z_/k71 p - p#j krho#j7;e7z_/k7 - #a72 7#af7 and if the liquid was incompressible1 the depth at pressure p would be 7p - p#j7_/p#j1 so that the lowering of the surface due to compression is ke7z_/k7 - k - z z_/k1 when k is large4 7#ag7 ,for sea water1 lambda is about #be1jjj atmospheres1 and k is then #be1jjj times the height of the water barometer1 about #bej1jjj metres1 so that in an ocean #aj kilometres deep the level is lowered about #bjj metres by the compressibility of the water2 and the density at the bottom is increased #d4 ,on another physical assumption of constant cubical elasticity lambda1 dp lambdadrho_/rho1 7p - p#j7_/lambda log7rho_/rho#j71 7#ah7 dp lambda drho _/ #a #a rho#j z -- -------- ------ rho1 lambda7 ------ - ----- 7 z1 #a - ------ ---1 lambda krho#j1 7#ai7 zd rho dz rho#j rho_/ rho k and the lowering of the surface is p - p#j rho _/ z z ------ - z k log ------ - z k log 7 #a - --- 7 - z approx --- 7#bj7 rho#j rho#j k _/ #bk as before in 7#ag74 #af4 ,centre of ,pressure4--,a plane area exposed to fluid pressure on one side experiences a single resultant thrust1 the integrated pressure over the area1 acting through a definite point called the centre of pressure 7,c4,p47 of the area4 ,thus if the plane is normal to ,oz1 the resultant thrust _/ _/ ,r pdxdy1 7#a7 _/_/ and the coordinates x1 y of the ,c4,p4 are given by _/ _/ _/ _/ x,r xp dx dy1 y,r yp dx dy4 7#b7 _/_/ _/_/ ,the ,c,p4 is thus the ,c,g4 of a plane lamina bounded by the area1 in which the surface density is p4 ,if p is uniform1 the ,c,p4 and ,c,g4 of the area coincide4 ,for a homogeneous liquid at rest under gravity1 p is proportional to the depth below the surface1 i4e4 to the perpendicular distance from the line of intersection of the plane of the area with the free surface of the liquid4 ,if the equation of this line1 referred to new coordinate axes in the plane area1 is written x cos alpha y sin alpha - h #j1 7#c7 _/ _/ ,r rho7h - x cos alpha - y sin alpha7 dx dy1 7#d7 _/_/ _/ _/ x,r rhox7h - x cos alpha - y sin alpha7 dx dy1 7#e7 _/_/ _/ _/ y,r rhoy7h - x cos alpha - y sin alpha7 dx dy4 _/_/ ,placing the new origin at the ,c4,g4 of the area ,a1 _/ _/ _/ _/ xd x dy #j1 y dx dy #j1 7#f7 _/_/ _/_/ ,r rhoh,a1 7#g7 _/ _/ _/ _/ xh,a -cos alpha x d,a - sin alpha xy d,a1 7#h7 _/_/ _/_/ _/ _/ _/ _/ yh,a -cos alpha xy d,a - sin alpha y d,a4 7#i7 _/_/ _/_/ ,turning the axes to make them coincide with the principal axes of the area ,a1 thus making intint xy d,a #j1 xh -a cos alpha1 yh -b sin alpha1 7#aj7 where _/ _/ _/ _/ x d,a ,aa1 y d,a ,ab1 7#aa7 _/_/ _/_/ a and b denoting the semi-axes of the momental ellipse of the area4 ,this shows that the ,c4,p4 is the antipole of the line of intersection of its plane with the free surface with respect to the momental ellipse at the ,c4,g4 of the area4 ,thus the ,c4,p4 of a rectangle or parallelogram with a side in the surface is at #b_/c of the depth of the lower side2 of a triangle with a vertex in the surface and base horizontal is of the depth of the base2 but if the base is in the surface1 the ,c,p4 is at half the depth of the vertex2 as on the faces of a tetrahedron1 with one edge in the surface4 ,the core of an area is the name given to the limited area round its ,c4,g4 within which the ,c,p4 must lie when the area is immersed completely2 the boundary of the core is therefore the locus of the antipodes with respect to the momental ellipse of water lines which touch the boundary of the area4 ,thus the core of a circle or an ellipse is a concentric circle or ellipse of one quarter the size4 ,the ,c4,p4 of water lines passing through a fixed point lies on a straight line1 the antipolar of the point2 and thus the core of a triangle is a similar triangle of one quarter the size1 and the core of a parallelogram is another parallelogram1 the diagonals of which are the middle third of the median lines4 ,in the design of a structure such as a tall reservoir dam it is important that the line of thrust in the material should pass inside the core of a section1 so that the material should not be in a state of tension anywhere and so liable to open and admit the water4 ,illustration3 ,,fig4 #c4 #ag4 ,equilibrium and ,stability of a ,ship or ,floating ,body4 ,the ,metacentre4--,the principle of ,archimedes in #ab leads immediately to the conditions of equilibrium of a body supported freely in fluid1 like a fish in water or a balloon in the air1 or like a ship 7fig4 #c7 floating partly immersed in water and the rest in air4 ,the body is in equilibrium under two forces3--7i47 its weight ,w acting vertically downward through ,g1 the ,c4,g4 of the body1 and 7ii47 the buoyancy of the fluid1 equal to the weight of the displaced fluid1 and acting vertically upward through ,b1 the ,c4,g4 of the displaced fluid2 for equilibrium these two forces must be equal and opposite in the same line4 ,the conditions of equilibrium of a body1 floating like a ship on the surface of a liquid1 are therefore3-- 7i47 the weight of the body must be less than the weight of the total volume of liquid it can displace2 or else the body will sink to the bottom of the liquid2 the difference of the weights is called the reserve of buoyancy4 7ii47 the weight of liquid which the body displaces in the position of equilibrium is equal to the weight ,w of the body2 and 7iii47 the ,c4,g41 ,b1 of the liquid displaced and ,g of the body1 must lie in the same vertical line ,,gb4 #ah4 ,in addition to satisfying these conditions of equilibrium1 a ship must fulfil the further condition of stability1 so as to keep upright2 if displaced slightly from this position1 the forces called into play must be such as to restore the ship to the upright again4 ,the stability of a ship is investigated practically by inclining it2 a weight is moved across the deck and the angle is observed of the heel produced4 ,suppose ,p tons is moved c ft4 across the deck of a ship of ,w tons displacement2 the ,c4,g4 will move from ,g to ,g#a the reduced distance ,g#a;,g#b c7,p_/,w72 and if ,b1 called the centre of buoyancy1 moves to ,b#a1 along the curve of buoyancy ,,bb#a1 the normal of this curve at ,b#a will be the new vertical ,b#a;,g#a1 meeting the old vertical in a point ,m1 the centre of curvature of ,,bb#a1 called the metacentre4 ,if the ship heels through an angle theta or a slope of #a in m1 ,,gm ,,gg#a;cottheta mc7,p_/,w71 7#a7 and ,,gm is called the metacentric height2 and the ship must be ballasted1 so that ,g lies below ,m4 ,if ,g was above ,m1 the tangent drawn from ,g to the evolute of ,b1 and normal to the curve of buoyancy1 would give the vertical in a new position of equilibrium4 ,thus in ,h4,m4,s4 ,achilles of #ijjj tons displacement it was found that moving #bj tons across the deck1 a distance of #db ft41 caused the bob of a pendulum #bj ft4 long to move through #aj in41 so that #bdj #bj ,,gm --- #db ---- #b4bd ft42 7#b7 #aj #ijjj also cot theta #bd1 theta #bbd4 7#c7 ,in a diagram it is conducive to clearness to draw the ship in one position1 and to incline the water-line2 and the page can be turned if it is desired to bring the new water-line horizontal4 ,suppose the ship turns about an axis through ,f in the water-line area1 perpendicular to the plane of the paper2 denoting by y the distance of an element d,a if the water-line area from the axis of rotation1 the change of displacement is sumyd,a tantheta1 so that there is no change of displacement if sumyd,a #j1 that is1 if the axis passes through the ,c4,g4 of the water-line area1 which we denote by ,f and call the centre of flotation4 ,the righting couple of the wedges of immersion and emersion will be ,sigmawy d,a tan thetay w tan theta ,sigma y d,a w tan theta,ak ft4 tons1 7#d7 w denoting the density of water in tons_/ft41 and ,w w,v1 for a displacement of ,v ft4 ,this couple1 combined with the original buoyancy ,w through ,b1 is equivalent to the new buoyancy through ,b1 so that ,w4,,bb#a w,ak tan theta1 7#e7 ,,bm ,,bb#a cot theta ,ak_/,v1 7#f7 giving the radius of curvature ,,bm of the curve of buoyancy ,b1 in terms of the displacement ,v1 and ,ak the moment of inertia of the water-line area about an axis through ,f1 perpendicular to the plane of displacement4 ,an inclining couple due to moving a weight about in a ship will heel the ship about an axis perpendicular to the plane of the couple1 only when this axis is a principal axis at ,f of the momental ellipse of the water-line area ,a4 ,for if the ship turns through a small angle theta about the line ,,ff1 then b#a1 b#b1 the ,c,g4 of the wedge of immersion and emersion1 will be the ,c,p4 with respect to ,,ff of the two parts of the water-line area1 so that b#a;b#b will be conjugate to ,,ff with respect to the momental ellipse at ,f4 ,the naval architect distinguishes between the stability of form1 represented by the righting couple ,w4,,bm1 and the stability of ballasting1 represented by ,w4,,bg4 ,ballasted with ,g at ,b1 the righting couple when the ship is heeled through theta is given by ,w4,,bm4 tantheta2 but if weights inside the ship are raised to bring ,g above ,b1 the righting couple is diminished by ,w4,,bg4tantheta1 so that the resultant righting couple is ,w,,gmtantheta4 ,provided the ship is designed to float upright at the smallest draft with no load on board1 the stability at any other draft of water can be arranged by the stowage of the weight1 high or low4 #ai4 ,proceeding as in #af for the determination of the ,c4,p4 of an area1 the same argument will show that an inclining couple due to the movement of a weight ,p through a distance c will cause the ship to heel through an angle theta about an axis ,,ff through ,f1 which is conjugate to the direction of the movement of ,p with respect to an ellipse1 not the momental ellipse of the water-line area ,a1 but a confocal to it1 of squared semi-axes a - h,v_/,a1 b - h,v_/,a1 7#a7 h denoting the vertical height ,,bg between ,c4,g4 and centre of buoyancy4 ,the varying direction of the inclining couple ,pc may be realized by swinging the weight ,p from a crane on the ship1 in a circle of radius c4 ,but if the weight ,p was lowered on the ship from a crane on shore1 the vessel would sink bodily a distance ,p_/w,a if ,p was deposited over ,f2 but deposited anywhere else1 say over ,q on the water-line area1 the ship would turn about a line the antipolar of ,q with respect to the confocal ellipse1 parallel to ,,ff1 at a distance ,,fk from ,f ,,fk 7k - h,v_/,a7_/,,fq sin ,,qff 7#b7 through an angle theta or a slope of one in m1 given by #a ,p ,p ,v sin theta --- ----- --- -------- ,,fq sin ,,qff1 7#c7 m w,a,,fk ,w ,ak - h,v where k denotes the radius of gyration about ,,ff of the water-line area4 ,burning the coal on a voyage has the reverse effect on a steamer4 ,,hydrodynamics #bj4 ,in considering the motion of a fluid we shall suppose it non-viscous1 so that whatever the state of motion the stress across any section is normal1 and the principle of the normality and thence of the equality of fluid pressure can be employed1 as in hydrostatics4 ,the practical problems of fluid motion1 which are amenable to mathematical analysis when viscosity is taken into account1 are excluded from treatment here1 as constituting a separate branch called hydraulics 7q4v474 ,two methods are employed in hydrodynamics1 called the ,eulerian and ,lagrangian1 although both are due originally to ,leonhard ,euler4 ,in the ,eulerian method the attention is fixed on a particular point of space1 and the change is observed there of pressure1 density and velocity1 which takes place during the motion2 but in the ,lagrangian method we follow up a particle of fluid and observe how it changes4 ,the first may be called the statistical method1 and the second the historical1 according to ,j4 ,c4 ,maxwell4 ,the ,lagrangian method being employed rarely1 we shall confine ourselves to the ,eulerian treatment4 ,the ,eulerian ,form of the ,equations of ,motion4 #ba4 ,the first equation to be established is the equation of continuity1 which expresses the fact that the increase of matter within a fixed surface is due to the flow of fluid across the surface into its interior4 ,in a straight uniform current of fluid of density rho1 flowing with velocity q1 the flow in units of mass per second across a plane area ,a1 placed in the current with the normal of the plane making an angle theta with the velocity1 is rho,aq cos theta1 the product of the density rho1 the area ,a1 and q cos theta the component velocity normal to the plane4 ,generally if ,s denotes any closed surface1 fixed in the fluid1 ,m the mass of the fluid inside it at any time t1 and theta the angle which the outward-drawn normal makes with the velocity q at that point1 d,m_/dt rate of increase of fluid inside the surface1 7#a7 flux across the surface into the interior _/ _/ - rhoq cos theta d,s1 _/_/ the integral equation of continuity4 ,in the ,eulerian notation u1 v1 w denote the components of the velocity q parallel to the coordinate axes at any point 7x1 y1 z7 at the time t2 u1 v1 w are functions of x1 y1 z1 t1 the independent variables2 and d is used here to denote partial differentiation with respect to any one of these four independent variables1 all capable of varying one at a time4 ,to transfer the integral equation into the differential equation of continuity1 ,green's transformation is required again1 namely1 _/ _/ _/ _/dxi deta dzeta _/ _/ 7 ----- ------ ------- 7dx dy dz 7lxi meta nzeta7 d,s1 7#b7 _/_/_/ dx dy dz _/ _/_/ or individually _/ _/ _/ dxi _/ _/ ----- dx dy dz lxi d,s14441 7#c7 _/_/_/ dx _/_/ where the integrations extend throughout the volume and over the surface of a closed space ,s2 l1 m1 n denoting the direction cosines of the outward-drawn normal at the surface element d,s1 and xi1 eta1 zeta any continuous functions of x1 y1 z4 ,the integral equation of continuity 7#a7 may now be written _/ _/ _/ drho _/ _/ ----- dx dy dz 7lrhou mrhov nrhow7 d,s #j1 7#d7 _/_/_/ dt _/_/ which becomes by ,green's transformation _/ _/ _/ _/drho d7rhou7 d7rhov7 d7rhow7 7 ------ --------- --------- -------- 7 dx dy dz #j1 7#e7 _/_/_/ dt dx dy dz _/ leading to the differential equation of continuity when the integration is removed4 #bb4 ,the equations of motion can be established in a similar way by considering the rate of increase of momentum in a fixed direction of the fluid inside the surface1 and equating it to the momentum generated by the force acting throughout the space ,s1 and by the pressure acting over the surface ,s4 ,taking the fixed direction parallel to the axis of x1 the time-rate of increase of momentum1 due to the fluid which crosses the surface1 is _/ _/ _/ _/ - rhouq cos theta d,s - 7lrhou mrhouv nrhouw7 d,s1 7#a7 _/_/ _/_/ which by ,green's transformation is _/ _/ _/ _/d7rhou7 d7rhouv7 d7rhouw7 - 7---------- ---------- ---------- 7 dx dy dz4 7#b7 _/_/_/ dx dy dz _/ ,the rate of generation of momentum in the interior of ,s by the component of force1 ,x per unit mass1 is _/ _/ _/ rho,x dx dy dz1 7#c7 _/_/_/ and by the pressure at the surface ,s is _/ _/ _/ _/ _/ dp - lp d,s - -- dx dy dz1 7#d7 _/_/ _/_/_/ dx by ,green's transformation4 ,the time rate of increase of momentum of the fluid inside ,s is _/ _/ _/ d7rhou7 --------- dx dy dz2 7#e7 _/_/_/ dt and 7#e7 is the sum of 7#a71 7#b71 7#c71 7#d71 so that _/ _/ _/ _/drhou drhou drhouv drhouw dp 7 ------- -------- -------- -------- - rho,x -- 7 dx dy dz #j1 7#f7 _/_/_/ dt dx dy dz dx _/ leading to the differential equation of motion drhou drhou drhouv1 drhouw dp ------- -------- -------- -------- rho,x - --1 7#g7 dt dx dy dz dx with two similar equations4 ,the absolute unit of force is employed here1 and not the gravitation unit of hydrostatics2 in a numerical application it is assumed that ,c4,g4,s4 units are intended4 ,these equations may be simplified slightly1 using the equation of continuity 7#e7 #ba2 for drhou drhou drhouv drhouw ------- -------- -------- -------- dt dx dy dz _/du du du du rho 7 -- u-- v-- w-- 7 dt dx dy dz _/ _/drho drhou drhov drhow u 7 ------ ------- ------- ------- 71 7#h7 dt dx dy dz _/ reducing to the first line1 the second line vanishing in consequence of the equation of continuity2 and so the equation of motion may be written in the more usual form du du du du #a dp -- u-- v-- w-- ,x - ----- --1 7#i7 dt dx dy dz rho dx with the two others dv dv dv dv #a dp -- u-- v-- w-- ,y - ----- --1 7#aj7 dt dx dy dz rho dy dw dw dw dw #a dp -- u-- v-- w-- ,z - ----- --4 7#aa7 dt dx dy dz rho dz #bc4 ,as a rule these equations are established immediately by determining the component acceleration of the fluid particle which is passing through 7x1 y1 z7 at the instant t of time considered1 and saying that the reversed acceleration or kinetic reaction1 combined with the impressed force per unit of mass and pressure-gradient1 will according to d',alembert's principle form a system in equilibrium4 ,to determine the component acceleration of a particle1 suppose ,f to denote any function of x1 y1 z1 t1 and investigate the time rate of ,f for a moving particle2 denoting the change by ,,df_/dt1 ,,df ,f7x udeltat1 y vdeltat1 z wdeltat1 t deltat7 - ,f7x1 y1 z1 t7 -- lt-------------------------------------- -------------------------------------- dt deltat d,f d,f d,f d,f -- u-- v-- w--2 7#a7 dt dx dy dz and ,d_/dt is called particle differentiation1 because it follows the rate of change of a particle as it leaves the point x1 y1 z2 but d,f_/dt1 d,f_/dx1 d,f_/dy1 d,f_/dz 7#b7 represent the rate of change of ,f at the time t1 at the point1 x1 y1 z1 fixed in space4 ,the components of acceleration of a particle of fluid are consequently ,du du du du du -- -- u-- v-- w--1 7#c7 dt dt dx dy dz ,dv dv dv dv dv -- -- u-- v-- w--1 7#d7 dt dt dx dy dz ,dw dw dw dw dw -- -- u-- v-- w--1 7#e7 dt dt dx dy dz leading to the equations of motion above4 ,if ,f 7x1 y1 z1 t7 #j represents the equation of a surface containing always the same particles of fluid1 ,,df d,f d,f d,f d,f -- #j1 or -- u-- v-- w-- #j1 7#f7 dt dt dx dy dz which is called the differential equation of the bounding surface4 ,a bounding surface is such that there is no flow of fluid across it1 as expressed by equation 7#f74 ,the surface always contains the same fluid inside it1 and condition 7#f7 is satisfied over the complete surface1 as well as any part of it4 ,but turbulence in the motion will vitiate the principle that a bounding surface will always consist of the same fluid particles1 as we see on the surface of turbulent water4 #bd4 ,to integrate the equations of motion1 suppose the impressed force is due to a potential ,v1 such that the force in any direction is the rate of diminution of ,v1 or its downward gradient2 and then ,x -d,v_/dx1 ,y -d,v_/dy1 ,z -d,v_/dz2 7#a7 and putting dw dv du dw dv du -- - -- #bxi1 -- - -- #b;eta1 -- - -- #bzeta1 7#b7 dy dz dz dx dx dy dxi deta dzeta ----- ------ ------- #j1 7#c7 dx dy dz the equations of motion may be written du d,h -- - #bvzeta #bweta -- #j1 7#d7 dt dx dv d,h -- - #bwxi #buzeta -- #j1 7#e7 dt dy dw d,h -- - #bueta #bwxi -- #j1 7#f7 dt dz where _/ ,h dp_/rho ,v q1 7#g7 _/ q u v w1 7#h7 and the three terms in ,h may be called the pressure head1 potential head1 and head of velocity1 when the gravitation unit is employed and q is replaced by q_/g4 ,eliminating ,h between 7#e7 and 7#f7 ,dxi du dv dw _/ du dv dw ----- - xi-- - eta-- - zeta-- xi7 -- -- -- 7 #j1 7#i7 dt dx dx dx dx dy dz _/ and combining this with the equation of continuity #a ,drho du dv dw ----- ------ -- -- -- #j1 7#aj7 rho dt dx dy dz we have ,d _/xi xi du eta dv zeta dw -- 7 ----- 7 - ----- -- - ----- -- - ------ -- #j1 7#aa7 dt rho_/ rho dx rho dx rho dx with two similar equations4 ,putting omega xi eta zeta1 7#ab7 a vortex line is defined to be such that the tangent is in the direction of omega1 the resultant of xi1 eta1 zeta1 called the components of molecular rotation4 ,a small sphere of the fluid1 if frozen suddenly1 would retain this angular velocity4 ,if omega vanishes throughout the fluid at any instant1 equation 7#aa7 shows that it will always be zero1 and the fluid motion is then called irrotational2 and a function phi exists1 called the velocity function1 such that udx vdy wdz -dphi1 7#ac7 and then the velocity in any direction is the space-decrease or downward gradient of phi4 #be4 ,but in the most general case it is possible to have three functions phi1 psi1 m of x1 y1 z1 such that udx vdy wdz -dphi - mdpsi1 7#a7 as ,a4 ,clebsch has shown1 from purely analytical considerations 7,crelle1 lvi472 and then d7psi1 m7 d7psi1 m7 d7psi1 m7 xi -----------1 eta -----------1 zeta -----------1 7#b7 d7y1 z7 d7z1 x7 d7x1 y7 and dpsi dpsi dpsi dm dm dm xi------ eta------ zeta------ #j1 xi-- eta-- zeta-- #j1 7#c7 dx dy dz dx dy dz so that1 at any instant1 the surfaces over which psi and m are constant intersect in the vortex lines4 ,putting dphi dpsi ,h - ------ - m ------ ,k1 7#d7 dt dt the equations of motion 7#d71 7#e71 7#f7 #bd can be written d,k d7psi1m7 -- - #buzeta #bweta - ---------- #j1 4441 4442 7#e7 dx d7x1t7 and therefore d,k d,k d,k xi-- eta-- zeta-- #j4 7#f7 dx dy dz ,equation 7#e7 becomes1 by a rearrangement1 d,k dpsi _/dm dm dm dm -- - ------ 7 -- u-- v-- w-- 7 dx dx dt dx dy dz _/ dm _/ dpsi dpsi dpsi dpsi -- 7 ------ u------ v------ w------ 7 #j1 4441 4441 7#g7 dx dt dx dy dz _/ d,k dpsi ,dm dm ,dpsi -- - ------ -- -- ------ #j1 4441 4441 7#h7 dx dx dt dx dt and as we prove subsequently 7 #cg7 that the vortex lines are composed of the same fluid particles throughout the motion1 the surface m and psi satisfies the condition of 7#f7 #bc2 so that ,k is uniform throughout the fluid at any instant1 and changes with the time only1 and so may be replaced by ,f7t74 #bf4 ,when the motion is steady1 that is1 when the velocity at any point of space does not change with the time1 d,k -- - #bvzeta #bweta #j1 4441 444 7#a7 dx d,k d,k d,k d,k d,k d,k xi-- eta-- zeta-- #j1 u-- v-- w-- #j1 7#b7 dx dy dz dx dy dz and _/ ,k dp_/rho ,v q ,h 7#c7 _/ is constant along a vortex line1 and a stream line1 the path of a fluid particle1 so that the fluid is traversed by a series of ,h surfaces1 each covered by a network of stream lines and vortex lines2 and if the motion is irrotational ,h is a constant throughout the fluid4 ,taking the axis of x for an instant in the normal through a point on the surface ,h constant1 this makes u #j1 xi #j2 and in steady motion the equations reduce to d,h_/dnu #bvzeta - #bweta #bqomega sin theta1 7#d7 where theta is the angle between the stream line and vortex line2 and this holds for their projection on any plane to which dnu is drawn perpendicular4 ,in plane motion 7#d7 reduces to d,h _/ d,q q ----- #bqzeta q 7 -- --- 71 7#e7 dnu dv r _/ if r denotes the radius of curvature of the stream line1 so that #a dp d,v d,h dq q ----- ----- ----- ----- - ----- ---1 7#f7 rho dnu dnu dnu dnu r the normal acceleration4 ,the osculating plane of a stream line in steady motion contains the resultant acceleration1 the direction ratios of which are du du du dq dq d,h u-- v-- w-- ---- - #bvzeta #bweta ---- - --1 4441 7#g7 dx dy dz dx dx dx and when q is stationary1 the acceleration is normal to the surface ,h constant1 and the stream line is a geodesic4 ,calling the sum of the pressure and potential head the statical head1 surfaces of constant statical and dynamical head intersect in lines on ,h1 and the three surfaces touch where the velocity is stationary4 ,equation 7#c7 is called ,bernoulli's equation1 and may be interpreted as the balance-sheet of the energy which enters and leaves a given tube of flow4 ,if homogeneous liquid is drawn off from a vessel so large that the motion at the free surface at a distance may be neglected1 then ,bernoulli's equation may be written ,h p_/rho z q_/#b;g ,p_/rho h1 7#h7 where ,p denotes the atmospheric pressure and h the height of the free surface1 a fundamental equation in hydraulics2 a return has been made here to the gravitation unit of hydrostatics1 and ,oz is taken vertically upward4 ,in particular1 for a jet issuing into the atmosphere1 where p ,p1 q_/#b;g h - z1 7#i7 or the velocity of the jet is due to the head k - z of the still free surface above the orifice2 this is ,torricelli's theorem 7#afdc71 the foundation of the science of hydrodynamics4 #bg4 ,uniplanar ,motion4--,in the uniplanar motion of a homogeneous liquid the equation of continuity reduces to du dv -- -- #j1 7#a7 dx dy so that we can put u -dpsi_/dy1 v dpsi_/dx1 7#b7 where psi is a function of x1 y1 called the stream- or current-function2 interpreted physically1 psi - psi#j1 the difference of the value of psi at a fixed point ,a and a variable point ,p is the flow1 in ft4_/second1 across any curved line ,,ap from ,a to ,p1 this being the same for all lines in accordance with the continuity4 ,thus if dpsi is the increase of psi due to a displacement from ,p to ,p1 and k is the component of velocity normal to ,,pp1 the flow across ,,pp is dpsi k,,pp2 and taking ,,pp parallel to ,ox1 dpsi vdx2 and similarly dpsi -udy with ,,pp parallel to ,oy2 and generally dpsi_/ds is the velocity across ds1 in a direction turned through a right angle forward1 against the clock4 ,in the equations of uniplanar motion dv du dpsi dpsi #bzeta -- - -- ------ ------ -,nablapsi1 suppose1 7#c7 dx dy dx dy so that in steady motion d,h dpsi d,h dpsi d,h -- ,nablapsi------ #j1 -- ,nablapsi------ #j1 ------ ,nablapsi #j1 7#d7 dx dx dy dy dpsi and ,nablapsi must be a function of psi4 ,if the motion ia irrotational1 dphi dpsi dphi dpsi u - ------ - ------1 v - ----- ------1 7#e7 dx dy dy dx so that psi and phi are conjugate functions of x and y1 phi psii f7x yi71 ,nablapsi #j1 ,nablaphi #j2 7#f7 or putting phi psii w1 x yi z1 w f7z74 ,the curves phi constant and psi constant form an orthogonal system2 and the interchange of phi and psi will give a new state of uniplanar motion1 in which the velocity at every point is turned through a right angle without alteration of magnitude4 ,for instance1 in a uniplanar flow1 radially inward towards ,o1 the flow across any circle of radius r being the same and denoted by #bpim1 the velocity must be m_/r1 and phi m log r1 psi mtheta1 phi psii m log re7itheta71 w m log z4 7#g7 ,interchanging these values psi m log r1 phi mtheta1 psi phii m log re7itheta7 7#h7 gives a state of vortex motion1 circulating round ,oz1 called a straight or columnar vortex4 ,a single vortex will remain at rest1 and cause a velocity at any point inversely as the distance from the axis and perpendicular to its direction2 analogous to the magnetic field of a straight electric current4 ,if other vortices are present1 any one may be supposed to move with the velocity due to the others1 the resultant stream-function being psi ,sigmam log r log ,pirm2 7#i7 the path of a vortex is obtained by equating the value of psi at the vortex to a constant1 omitting the rm of the vortex itself4 ,when the liquid is bounded by a cylindrical surface1 the motion of a vortex inside may be determined as due to a series of vortex-images1 so arranged as to make the flow zero across the boundary4 ,for a plane boundary the image is the optical reflection of the vortex4 ,for example1 a pair of equal opposite vortices1 moving on a line parallel to a plane boundary1 will have a corresponding pair of images1 forming a rectangle of vortices1 and the path of a vortex will be the ,cotes' spiral r sin #btheta #b;a1 or x7-#b7 y7-#b7 a7-#b72 7#aj7 this is therefore the path of a single vortex in a right-angled corner2 and generally1 if the angle of the corner is pi_/n1 the path is the ,cotes' spiral r sin ntheta na4 7#aa7 ,a single vortex in a circular cylinder of radius a at a distance c from the centre will move with the velocity due to an equal opposite image at a distance a_/c1 and so describe a circle with velocity mc_/7a - c7 in the periodic time #bpi7a - c7_/m4 7#ab7 ,conjugate functions can be employed also for the motion of liquid in a thin sheet between two concentric spherical surfaces2 the components of velocity along the meridian and parallel in colatitude theta and longitude lambda can be written dphi #a dpsi #a dpsi dpsi -------- ----------- ---------1 ----------- --------- - --------1 7#ac7 dtheta sin theta dlambda sin theta dlambda dtheta and then phi psii ,f7tan thetae7lambdai774 7#ad7 #bh4 ,uniplanar ,motion of a ,liquid due to the ,passage of a ,cylinder through it4--,a stream-function psi must be determined to satisfy the conditions ,nablapsi #j1 throughout the liquid2 7#a7 psi constant1 over any fixed boundary2 7#b7 dpsi_/ds normal velocity reversed over a solid boundary1 7#c7 so that1 if the solid is moving with velocity ,u in the direction ,ox1 dpsi_/ds -,udy_/ds1 or psi ,uy constant over the moving cylinder2 and psi ,uy psi is the stream function of the relative motion of the liquid past the cylinder1 and similarly psi - ,vx for the component velocity ,v along ,oy2 and generally psi psi ,uy - ,vx 7#d7 is the relative stream-function1 constant over a solid boundary moving with components ,u and ,v of velocity4 ,if the liquid is stirred up by the rotation ,r of a cylindrical body1 dpsi_/ds normal velocity reversed dx dy -,rx-- - ,ry--1 7#e7 ds ds psi ,r7x y7 psi1 7#f7 a constant over the boundary2 and psi is the current-function of the relative motion past the cylinder1 but now ,vpsi #b,r #j1 7#g7 throughout the liquid4 ,inside an equilateral triangle1 for instance1 of height h1 psi -#b,ralphabetagamma_/h1 7#h7 where alpha1 beta1 gamma are the perpendiculars on the sides of the triangle4 ,in the general case psi psi ,uy - ,vx ,r7x y7 is the relative stream function for velocity components1 ,u1 ,v1 ,r4 #bi4 ,example #a4--,liquid motion past a circular cylinder4 ,consider the motion given by omega ,u7z a_/z71 7#a7 so that _/ a _/ a phi ,u 7 r -- 7 cos theta ,u 7 #a -- 7x1 7#b7 r _/ r _/ _/ a _/ a psi ,u 7 r - -- 7 sin theta ,u 7 #a - -- 7y4 r _/ r _/ ,then psi #j over the cylinder r a1 which may be considered a fixed post2 and a stream line past it along which psi ,uc1 a constant1 is the curve _/ a 7 r - -- 7 sin theta c1 7x y77y - c7 - ay #j 7#c7 r _/ a cubic curve 7,c#c74 ,over a concentric cylinder1 external or internal1 of radius r b1 _/ a psi psi ,u#ay ,u 7 #a - --- 7 ,u#a y1 7#d7 b_/ and psi is zero if ,u#a_/,u 7a - b7_/b2 7#e7 so that the cylinder may swim for an instant in the liquid without distortion1 with this velocity ,u#a1 and omega in 7#a7 will give the liquid motion in the interspace between the fixed cylinder r a and the concentric cylinder r b1 moving with velocity ,u#a4 ,when b #j1 ,u#a oo2 and when b oo1 ,u#a -,u1 so that at infinity the liquid is streaming in the direction x,o with velocity ,u4 ,if the liquid is reduced to rest at infinity by the superposition of an opposite stream given by omega -,uz1 we are left with omega ,ua_/z1 7#f7 phi ,u7a_/r7 cos theta ,uax_/7x y71 7#g7 psi -,u7a_/r7 sin theta -,uay_/7x y71 7#h7 giving the motion due to the passage of the ,cylinder r a with velocity ,u through the origin ,o in the direction ,ox4 ,if the direction of motion makes an angle theta with ,ox1 dphi _/ dphi #bxy tantheta ----- _/ ----- ------ tan #btheta1 theta theta1 7#i7 dy _/ dx x - y and the velocity is ,ua_/r4 ,along the path of a particle1 defined by the ,c#c of 7#c71 y y7y - c7 sin theta ------- -------1 7#aj7 x y a dtheta #by - c dy sin theta --------- ------ --1 7#aa7 ds a ds on the radius of curvature is a_/7y - c71 which shows that the curve is an ,elastica or ,lintearia4 7,j4 ,c4 ,maxwell1 ,collected ,works1 ii4 #bjh47 ,if phi#a denotes the velocity function of the liquid filling the cylinder r b1 and moving bodily with it with velocity ,u#a1 phi#a -,u#ax1 7#ab7 and over the separating surface r b phi ,u _/ a a b --------- - -- 7 #a -- 7 -------1 7#ac7 phi#a ,u#a b_/ a - b and this1 by #cf1 is also the ratio of the kinetic energy in the annular interspace between the two cylinders to the kinetic energy of the liquid moving bodily inside r b4 ,consequently the inertia to overcome in moving the cylinder r b1 solid or liquid1 is its own inertia1 increased by the inertia of liquid 7a b7_/7a - b7 times the volume of the cylinder r b2 this total inertia is called the effective inertia of the cylinder r b1 at the instant the two cylinders are concentric4 ,with liquid of density rho1 this gives rise to a kinetic reaction to acceleration d,u_/dt1 given by a b d,u a b d,u pirhob ------- -- ------- ,m--1 7#ad7 a - b dt a - b dt if ,m denotes the mass of liquid displaced by unit length of the cylinder r b4 ,in particular1 when a oo1 the extra inertia is ,m4 ,when the cylinder r a is moved with velocity ,u and r b with velocity ,u#a along ,ox1 a _/ b b _/ a phi ,u ------- 7 --- r 7 cos theta - ,u#a------- 7 r --- 7 cos theta1 7#ae7 b - a r _/ b - a r _/ a _/ b b _/ a psi -,u ------- 7 --- - r 7 sin theta - ,u#a------- 7 r - --- 7 sin theta2 7#af7 b - a r _/ b - a r _/ and similarly1 with velocity components ,v and ,v#a along ,oy a _/ b b _/ a phi ,v ------- 7 --- r 7 sin theta - ,v#a------- 7 r --- 7 sin theta1 7#ag7 b - a r _/ b - a r _/ a _/ b b _/ a psi ,v ------- 7 --- - r 7 cos theta ,v#a------- 7 r - --- 7 cos theta1 7#ah7 b - a r _/ b - a r _/ and then for the resultant motion a z ab ,u ,vi w 7,u ,v7 ------- ------ ------- ------ b - a ,u ,vi b - a z a z ab ,u#a ,v#a;i -7,u#a ,v#a7 ------- -------- ------- --------4 7#ai7 b - a ,u#a ,v#a;i b - a z ,the resultant impulse of the liquid on the cylinder is given by the component1 over r a 7 #cf71 _/ _/ b a #b;b ,x rhophi cos thetaadtheta pirhoa 7 ,u ------- - ,u#a ------- 72 7#bj7 _/ b - a b - a_/ and over r b _/ _/ #b;a b a ,x#a rhophi cos thetabdtheta pirhob 7 ,u ------ - ,u#a------- 71 7#ba7 _/ b - a b - a _/ and the difference ,x - ,x#a is the component momentum of the liquid in the interspace2 with similar expressions for ,y and ,y#a4 ,then1 if the outside cylinder is free to move ,v#a #b;a b - a ,x#a #j1 -- -------1 ,x pirhoa,u -------4 7#bb7 ,u b a b a ,but if the outside cylinder is moved with velocity ,u#a1 and the inside cylinder is solid or filled with liquid of density sigma1 ,u#a #brhob ,x -pirhoa,u1 -- --------------------------------1 ,u rho7b a7 sigma7b - a7 ,u - ,u#a 7rho - sigma77b - a7 ------ ---------------------------------1 7#bc7 ,u#a rho7b a7 sigma7b - a7 and the inside cylinder starts forward or backward with respect to the outside cylinder1 according as rho or sigma4 #cj4 ,the expression for omega in 7#a7 #bi may be increased by the addition of the term im log z -mtheta im log r1 7#a7 representing vortex motion circulating round the annulus of liquid4 ,considered by itself1 with the cylinders held fixed1 the vortex sets up a circumferential velocity m_/r on a radius r1 so that the angular momentum of a circular filament of annular cross section d,a is rhomd,a1 and of the whole vortex is rhompi7b - a74 ,any circular filament can be started from rest by the application of a circumferential impulse pirhomdr at each end of a diameter2 so that a mechanism attached to the cylinders1 which can set up a uniform distributed impulse pirhom across the two parts of a diameter in the liquid1 will generate the vortex motion1 and react on the cylinder with an impulse couple -rhompia and rhompib1 having resultant rhompi7b - a71 and this couple is infinite when b oo1 as the angular momentum of the vortex is infinite4 ,round the cylinder r a held fixed in the ,u current the liquid streams past with velocity q #b,u sin theta m_/a2 7#b7 and the loss of head due to this increase of velocity from ,u to q is q - ,u 7#b,u sin theta m_/a7 - ,u -------- ----------------------------1 7#c7 #b;g #b;g so that cavitation will take place1 unless the head at a great distance exceeds this loss4 ,the resultant hydrostatic thrust across any diametral plane of the cylinder will be modified1 but the only term in the loss of head which exerts a resultant thrust on the whole cylinder is #bm,u sintheta_/ga1 and its thrust is #bpirhom,u absolute units in the direction ,cy1 to be counteracted by a support at the centre ,c2 the liquid is streaming past r a with velocity ,u reversed1 and the cylinder is surrounded by a vortex4 ,similarly1 the streaming velocity ,v reversed will give rise to a thrust #bpirhom,v in the direction x,c4 ,now if the cylinder is released1 and the components ,u and ,v are reversed so as to become the velocity of the cylinder with respect to space filled with liquid1 and at rest at infinity1 the cylinder will experience components of force per unit length 7i47 - #bpirhom,v1 #bpirhom,u1 due to the vortex motion2 7ii47 - pirhoa d,u_/dt1 -pirhoa d,v_/dt1 due to the kinetic reaction of the liquid2 7iii47 #j1 -pi7sigma - rho7ag1 due to gravity1 taking ,oy vertically upward1 and denoting the density of the cylinder by sigma2 so that the equations of motion are d,u d,u pirhoa-- - pirhoa-- - #bpirhom,v1 7#d7 dt dt d,v d,v pirhoa-- - pirhoa-- #bpirhom,v - pi7sigma - rho7ag1 7#e7 dt dt or1 putting m aomega1 so that the vortex velocity is due to an angular velocity omega at a radius a1 7sigma rho7d,u_/dt #brhoomega,v #j1 7#f7 7sigma rho7d,v_/dt - #brhoomega,u 7sigma - rho7g #j4 7#g7 ,thus with g #j1 the cylinder will describe a circle with angular velocity #brhoomega_/7sigma rho71 so that the radius is 7sigma rho7v_/#brhoomega1 if the velocity is v4 ,with sigma #j1 the angular velocity of the cylinder is #bomega2 in this way the velocity may be calculated of the propagation of ripples and waves on the surface of a vertical whirlpool in a sink4 ,restoring sigma will make the path of the cylinder a trochoid2 and so the swerve can be explained of the ball in tennis1 cricket1 baseball1 or golf4 ,another explanation may be given of the sidelong force1 arising from the velocity of liquid past a cylinder1 which is encircled by a vortex4 ,taking two planes x b1 and considering the increase of momentum in the liquid between them1 due to the entry and exit of liquid momentum1 the increase across dy in the direction ,oy1 due to elements at ,p and ,p at opposite ends of the diameter ,,pp1 is rhody 7,u - ,uar7-#b7 cos #btheta mr7-#a7 sin theta77,uar7-#b7 sin #btheta mr7-#a7 cos theta7 rhody 7- ,u ,uar7-#b7 cos #btheta mr7-#a7 sin theta77,uar7-#b7 sin #btheta - mr7-#a7 cos theta7 #brhodym,ur7-#a77;cos theta - a#br7-#b7;cos #ctheta71 7#h7 and with y b tan theta1 r b sec theta1 this is #brhom,udtheta 7#a - ab7-#b7 cos #ctheta cos theta71 7#i7 and integrating between the limits theta pi1 the resultant1 as before1 is #bpirhom,u4 #ca4 ,example #b4--;,confocal ,elliptic ,cylinders4--,employ the elliptic coordinates eta1 xi1 and zeta eta xii1 such that z c chzeta1 x c ch eta cos xi1 y c sh eta sin zeta2 7#a7 then the curves for which eta and xi are constant are confocal ellipses and hyperbolas1 and d7x1 y7 ,j -------1 xi7 c7cheta - cos xi7 d7eta c7ch #b;eta - cos #bxi7 r#ar#b ,,od1 7#b7 if ,,od is the semi-diameter conjugate to ,,op1 and r#a1 r#b the focal distances1 r#a1 r#b c7cheta cos xi72 7#c7 r x y c7cheta - sin xi7 c7ch #b;eta cos #bxi74 7#d7 ,consider the streaming motion given by w m ch7zeta - gamma71 gamma alpha betai1 7#e7 phi m ch7eta - alpha7 cos 7xi - beta71 psi m sh7eta - alpha7 sin 7xi - beta74 7#f7 ,then psi #j over the ellipse eta alpha1 and the hyperbola xi beta1 so that these may be taken as fixed boundaries2 and psi is a constant on a ,c#d4 ,over any ellipse eta1 moving with components ,u and ,v of velocity1 psi psi ,uy - ,vx m sh7eta - alpha7 cos beta ,uc sheta sin xi -m sh 7eta - alpha7 sin beta ,vc ch eta cos xi2 7#g7 so that psi #j1 if m sh7eta - alpha7 m sh7eta - alpha7 ,u - --- ------------------- cos beta1 ,v - --- - ------------------- sin beta1 7#h7 c sheta c cheta having a resultant in the direction ,,po1 where ,p is the intersection of an ellipse eta with the hyperbola beta2 and with this velocity the ellipse eta can be swimming in the liquid1 without distortion for an instant4 ,at infinity m m ,u - --- e7-a7 cos beta - ----- cos beta1 c a - b m m ,v - --- e7-a7 sin beta - ----- sin beta1 7#i7 c a b a and b denoting the semi-axes of the ellipse alpha2 so that the liquid is streaming at infinity with velocity ,q m_/7a b7 in the direction of the asymptote of the hyperbola beta4 ,an ellipse interior to eta alpha will move in a direction opposite to the exterior current2 and when eta #j1 ,u oo1 but ,v 7m_/c7 sh alpha sin beta4 ,negative values of eta must be interpreted by a streaming motion on a parallel plane at a level slightly different1 as on a double ,riemann sheet1 the stream passing from one sheet to the other across a cut ,,ss joining the foci ,s1 ,s4 ,a diagram has been drawn by ,col4 ,r4 ,l4 ,hippisley4 ,the components of the liquid velocity q1 in the direction of the normal of the ellipse eta and hyperbola xi1 are -m,j7-#a7sh7eta - alpha7 cos7xi - beta71 m,j7-#a7;ch7eta - alpha7 sin 7xi - beta74 7#aj7 ,the velocity q is zero in a corner where the hyperbola beta cuts the ellipse alpha2 and round the ellipse alpha the velocity q reaches a maximum when the tangent has turned through a right angle1 and then root7ch #b;alpha - cos #b;beta7 q ,qea ---------------------------------2 7#aa7 sh #b;alpha and the condition can be inferred when cavitation begins4 ,with beta #j1 the stream is parallel to x#j1 and phi m ch7eta - alpha7cos xi -,uc ch7eta - alpha7sh eta cos xi_/sh7eta - alpha7 7#ab7 over the cylinder eta1 and as in 7#ab7 #bi1 phi#a -,ux -,uc ch eta cos xi1 7#ac7 for liquid filling the cylinder2 and phi th eta ------ --------------------1 7#ad7 phi#a th 7eta - alpha7 over the surface of eta2 so that parallel to ,ox1 the effective inertia of the cylinder eta1 displacing ,m liquid1 is increased by ,mth eta_/th7eta- alpha71 reducing when alpha oo to ,mth eta ,m7b_/a74 ,similarly1 parallel to ,oy1 the increase of effective inertia is ,m_/th eta th7eta - alpha71 reducing to ,m_/th eta ,m7a_/b71 when alpha oo1 and the liquid extends to infinity4 #cb4 ,next consider the motion given by phi m ch #b7;eta - alpha7 sin #bxi1 psi -m sh #b7;eta - alpha7 cos #bxi2 7#a7 in which psi #j over the ellipse alpha1 and psi psi ,r7x y7 -m sh #b7;eta - alpha7 ,rc cos #bxi ,rc ch #b;eta1 7#b7 which is constant over the ellipse eta if ,rc m sh #b7;eta - alpha72 7#c7 so that this ellipse can be rotating with this angular velocity ,r for an instant without distortion1 the ellipse alpha being fixed4 ,for the liquid filling the interior of a rotating elliptic cylinder of cross section x_/a y_/b #a1 7#d7 psi#a m#a7x_/a y_/b7 7#e7 with nablapsi#a -#b,r -#bm#a7a_/;a #a_/;b71 psi#a m#a7x_/a y_/b7 - ,r7x y7 -,r7x - y77a - b7_/7a b71 7#f7 phi#a ,rxy7a - b7_/7a b71 w#a phi#a psi#a;i -i,r7x yi77a - b7_/7a b74 ,the velocity of a liquid particle is thus 7a - b7_/7a b7 of what it would be if the liquid was frozen and rotating bodily with the ellipse2 and so the effective angular inertia of the liquid is 7a - b7_/7a b7 of the solid2 and the effective radius of gyration1 solid and liquid1 is given by k 7a b71 and 7a - b7_/7a b74 7#g7 ,for the liquid in the interspace between alpha and eta1 phi m ch #b7;eta - alpha7 sin #bxi ------ ---------------------------------------- --- phi#a ,rc sh #b;eta sin #bxi7a - b7_/7a b7 #a_/th #b7;eta - alpha7th #b;eta2 7#h7 and the effective k of the liquid is reduced to c_/th #b7;eta - alpha7 sh #b;eta1 7#i7 which becomes c_/sh #b;eta #a_/h 7a - b7_/ab1 when alpha oo1 and the liquid surrounds the ellipse eta to infinity4 ,an angular velocity ,r1 which gives components -,ry1 ,rx of velocity to a body1 can be resolved into two shearing velocities1 -,r parallel to ,ox1 and ,r parallel to ,oy2 and then psi is resolved into psi#a psi#b1 such that psi#a ,rx and psi#b ,ry is constant over the boundary4 ,inside a cylinder phi#a psi#a;i -i,r7x yi7a_/7a b71 7#aj7 phi#b psi#b;i i,r7x yi7b_/7a b71 7#aa7 and for the interspace1 the ellipse alpha being fixed1 and alpha#a revolving with angular velocity ,r phi#a psi#a;i -#a_/h i,rcsh #b7;eta - alpha xii77ch #b;alpha #a7_/sh #b7;alpha#a - alpha71 7#ab7 phi#b psi#b;i #a_/h i,rcsh #b7;eta - alpha xii77ch #b;alpha - #a7_/sh #b7;alpha#a - alpha71 7#ac7 satisfying the condition that psi#a and psi#b are zero over eta alpha1 and over eta alpha#a psi#a ,rx #a_/h ,rc7ch #b;alpha#a #a71 7#ad7 psi#b ,ry #a_/h ,rc7ch #b;alpha#a - #a71 7#ae7 constant values4 ,in a similar way the more general state of motion may be analysed1 given by w m ch #b7zeta - gamma71 gamma alpha betai1 7#af7 as giving a homogeneous strain velocity to the confocal system2 to which may be added a circulation1 represented by an additional term mzeta in w4 ,similarly1 with x yi crootsin 7xi etai7 7#ag7 the function psi ,qc sh 7eta - alpha7 sin 7xi - beta7 7#ah7 will give motion streaming past the fixed cylinder eta alpha1 and dividing along xi beta2 and then x - y c sin xi ch eta1 #bxy c cos xi sh eta4 7#ai7 ,in particular1 with sh alpha #a1 the cross-section of eta alpha is x#d #fxy y#d #b;c#d1 or x#d y#d c#d 7#bj7 when the axes are turned through #de4 #cc4 ,example #c4--;,analysing in this way the rotation of a rectangle filled with liquid into the two components of shear1 the stream function psi#a is to be made to satisfy the conditions 7i47 nablapsi#a #j1 7ii47 psi#a ,rx ,ra1 or psi#a #j when x a1 7iii47 psi#a ,rx ,ra1 psi#a ,r7a - x71 when y b4 ,expanded in a ,fourier series1 #cb cos 7#bn #a7 pix_/a a - x ----- a ---------------------1 7#a7 pi _/ 7#bn #a7 so that #af cos 7#bn #a7 pix_/a ch7#bn #a7 piy_/a7 psi#a ----- a ---------------------------------------- -----1 pi _/ 7#bn #a7c ch7#bn #a7 pib_/a #af cos 7#bn #a7 piz_/a w#a phi#a psi#a;i i,r ----- ------------------------------1 7#b7 pi _/ 7#bn #a7c ch7#bn #a7 pib_/a an elliptic-function ,fourier series2 with a similar expression for psi#b with x and y1 a and b interchanged2 and thence psi psi#a psi#b4 ,example #d4--,parabolic cylinder1 axial advance1 and liquid streaming past4 ,the polar equation of the cross-section being r cos theta a1 or r x #b;a1 7#c7 the conditions are satisfied by psi ,ur sin theta - #b,ua r sin theta #b,ur sin theta7r cos theta - a71 7#d7 psi #b,ua r sin theta -,uroot#b;a7r-x71 7#e7 w -#b,ua z1 7#f7 and the resistance of the liquid is #bpirhoa,v_/#b;g4 ,a relative stream line1 along which psi ,uc1 is the quartic curve 7#d;ay - 7y - c7#d #d;ay 7y-c7#d y - c root#b;a7r - x71 x -------------------1 r ---------------1 7#g7 7#d;a7y - c7 #d;a7y - c7 and in the absolute space curve given by psi1 dy 7y - c7 #b;ac -- - --------1 x - ----- #b;a log 7y - c74 7#h7 dx #b;ay y - c #cd4 ,motion symmetrical about an ,axis4--,when the motion of a liquid is the same for any plane passing through ,ox1 and lies in the plane1 a function psi can be found analogous to that employed in plane motion1 such that the flux across the surface generated by the revolution of any curve ,,ap from ,a to ,p is the same1 and represented by #bpi7psi - psi#j72 and1 as before1 if dpsi is the increase in psi due to a displacement of ,p to ,p1 then k the component of velocity normal to the surface swept out by ,,pp is such that #bpidpsi #bpiyk4,,pp2 and taking ,,pp parallel to ,oy and ,ox1 u -dpsi_/ydy1 v dpsi_/ydx1 7#a7 and psi is called after the inventor1 ,stokes's stream or current function1 as it is constant along a stream line 7,trans4 ,camb4 ,phil4 ,soc41 #ahdb2 ,stokes's ,current ,function1 ,r4 ,a4 ,sampson1 ,phil4 ,trans41 #ahib72 and dpsi_/yds is the component velocity across ds in a direction turned through a right angle forward4 ,in this symmetrical motion d _/ #a dpsi d _/ #a dpsi xi #j1 eta #j1 #bzeta -- 7 --- ------ 7 -- 7 --- ------ 7 dx y dx _/ dy y dy _/ #a _/dpsi dpsi #a dpsi #a --- 7 ------- ------- - --- ------ 7 - ---nablapsi1 7#b7 y dx dy y dy _/ y suppose2 and in steady motion1 d,h #a dpsi d,h #a dpsi -- --- ----- nablapsi #j1 -- --- ------ nablapsi #j1 7#c7 dx y dx dy y dy so that #bzeta_/y -y7-#b7nablapsi d,h_/dpsi 7#d7 is a function of psi1 say f7psi71 and constant along a stream line2 d,h_/dv #bqzeta1 ,h - f7psi7 constant1 7#e7 throughout the liquid4 ,when the motion is irrotational1 dphi #a dpsi dphi #a dpsi zeta #j1 u - ------ - --- ------1 v - ------ --- ------1 7#f7 dx y dy dy y dx dpsi dpsi #a dpsi nablapsi #j1 or ------- ------- - --- ------ #j4 7#g7 dx dy y dy ,changing to polar coordinates1 x r costheta1 y r sintheta1 the equation 7#b7 becomes1 with costheta mu1 dpsi dpsi r------- 7#a - mu7 ------- #bzetar sin theta1 7#h7 dr dmu of which a solution1 when zeta #j1 is _/ ,b d,pn _/ ,b d,pn psi 7 ,ar7n#a7 --- 7 7#a - mu7 ----- 7 ,ar7n-#a7 ------- 7 y-----1 7#i7 rn _/ dmu r7n#b7 _/ dmu phi 7n #a7;,arn - n,br7-n-#a7 ,pn1 7#aj7 where ,pn denotes the zonal harmonic of the nth order2 also1 in the exceptional case of psi ,a#j costheta1 phi ,a#j_/r2 psi ,b#jr1 phi -,b#j log tan theta -,b#j sh7-#a7 x_/y4 7#aa7 ,thus costheta is the ,stokes' function of a point source at ,o1 and ,,pa - ,,pb of a line source ,,ab4 ,the stream function psi of the liquid motion set up by the passage of a solid of revolution1 moving with axial velocity ,u1 is such that #a dpsi dy --- ------ -,u --1 psi ,uy constant1 7#ab7 y ds ds over the surface of the solid2 and psi must be replaced by psi psi ,uy in the general equations of steady motion above to obtain the steady relative motion of the liquid past the solid4 ,for instance1 with n #a in equation 7#i71 the relative stream function is obtained for a sphere of radius a1 by making it psi psi ,uy ,u7r - a_/r7 sin theta1 psi -,ua sin theta_/r2 7#ac7 and then phi ,ux7#a a_/r71 phi ,ua cos theta_/r1 7#ad7 dphi a dphi a - ------ ,u -- cos theta1 - --------- ,u -- sin theta1 7#ae7 dr r rdtheta r so that1 if the direction of motion makes an angle psi with ,ox1 tan 7psi - theta7 tan theta1 tan psi #c tan theta_/7#b - tan theta71 7#af7 ,along the path of a liquid particle psi is constant1 and putting it equal to ,uc1 7r - a_/r7 sin theta c1 sin theta cr_/7r - a71 7#ag7 the polar equation2 or y cr_/7r - a71 r ay_/7y - c71 7#ah7 a curve of the #ajth degree 7,c#aj74 ,in the absolute path in space cos psi 7#b - #c sin theta7_/root7#d - sin theta71 and sin theta 7y - cy7_/a1 7#ai7 which leads to no simple relation4 ,the velocity past the surface of the sphere is #a dpsi _/ a sin theta ------------ ------- ,u 7 #br -- 7 ------------- #c_/b ,u sin theta1 when r a2 7#bj7 r sintheta dr r _/ r sin theta so that the loss of head is 7#i_/d sin theta - #a7 ,u_/#b;g1 having a maximum #e_/d ,u_/#b;g1 7#ba7 which must be less than the head at infinite distance to avoid cavitation at the surface of the sphere4 ,with n #b1 a state of motion is given by psi -,uya#dmu_/r#d1 psi ,uy7#a - a#dmu_/r#d71 7#bb7 phi ,ux phi1 phi -#a_/c ,u7a#d_/r7,p#b1 ,p#b #c_/b mu - 1 7#bc7 representing a stream past the surface r#d a#dmu4 #ce4 ,a circular vortex1 such as a smoke ring1 will set up motion symmetrical about an axis1 and provide an illustration2 a half vortex ring can be generated in water by drawing a semicircular blade a short distance forward1 the tip of a spoon for instance4 ,the vortex advances with a certain velocity2 and if an equal circular vortex is generated coaxially with the first1 the mutual influence can be observed4 ,the first vortex dilates and moves slower1 while the second contracts and shoots through the first2 after which the motion is reversed periodically1 as if in a game of leap-frog4 ,projected perpendicularly against a plane boundary1 the motion is determined by an equal opposite vortex ring1 the optical image2 the vortex ring spreads out and moves more slowly as it approaches the wall2 at the same time the molecular rotation1 inversely as the cross-section of the vortex1 is seen to increase4 ,the analytical treatment of such vortex rings is the same as for the electro-magnetic effect of a current circulating in each ring4 #cf4 ,irrotational ,motion in ,general4--,liquid originally at rest in a singly-connected space cannot be set in motion by a field of force due to a single-valued potential function2 any motion set up in the liquid must be due to a movement of the boundary1 and the motion will be irrotational2 for any small spherical element of the liquid may be considered a smooth solid sphere for a moment1 and the normal pressure of the surrounding liquid cannot impart to it any rotation4 ,the kinetic energy of the liquid inside a surface ,s due to the velocity function phi is given by _/ _/ _/ _/dphi _/dphi _/dphi ,t rho 7 ------ 7 7 ------ 7 7 ------ 7 dx dy dz1 _/_/_/ dx _/ dy _/ dz _/ _/ _/ dphi rho phi ------ d,s 7#a7 _/_/ dnu by ,green's transformation1 dnu denoting an elementary step along the normal to the exterior of the surface2 so that dphi_/dnu #j over the surface makes ,t #j1 and then _/dphi _/dphi _/dphi dphi dphi dphi 7 ------ 7 7 ------ 7 7 ------ 7 #j1 ------ #j1 ------ #j1 ------ #j 7#b7 dx _/ dy _/ dz _/ dx dy dz ,if the actual motion at any instant is supposed to be generated instantaneously from rest by the application of pressure impulse over the surface1 or suddenly reduced to rest again1 then1 since no natural forces can act impulsively throughout the liquid1 the pressure impulse omega satisfies the equations #a domega #a domega #a domega ----- --------- -u1 ----- --------- -v1 ----- --------- -omega1 7#c7 rho dx rho dy rho dz omega rhophi a constant1 7#d7 and the constant may be ignored2 and ,green's transformation of the energy ,t amounts to the theorem that the work done by an impulse is the product of the impulse and average velocity1 or half the velocity from rest4 ,in a multiply connected space1 like a ring1 with a multiply valued velocity function phi1 the liquid can circulate in the circuits independently of any motion of the surface2 thus1 for example1 phi mtheta m tan7-#a7 y_/x 7#e7 will give motion to the liquid1 circulating in any ring-shaped figure of revolution round ,oz4 ,to find the kinetic energy of such motion in a multiply connected space1 the channels must be supposed barred1 and the space made acyclic by a membrane1 moving with the velocity of the liquid2 and then if k denotes the cyclic constant of phi in any circuit1 or the value by which phi has increased in completing the circuit1 the values of phi on the two sides of the membrane are taken as differing by k1 so that the integral over the membrane _/ _/ dphi _/ _/ dphi phi ------ d,s k ------ d,s1 7#f7 _/_/ dnu _/_/ dnu and this term is to be added to the terms in 7#a7 to obtain the additional part in the kinetic energy2 the continuity shows that the integral is independent of the shape of the barrier membrane1 and its position4 ,thus1 in 7#e71 the cyclic constant k #bpim4 ,in plane motion the kinetic energy per unit length parallel to ,oz _/ _/ _/dphi _/dphi _/ _/ _/dpsi _/dpsi ,t rho 7 ------ 7 7 ------ 7 dx dy rho 7 ------ 7 7 ------ 7 dx dy _/_/ dx _/ dy _/ _/_/ dx _/ dy _/ _/ dphi _/ dphi rho phi ------ ds rho psi ------ ds4 7#g7 _/ dnu _/ dnu ,for example1 in the equilateral triangle of 7#h7 #bh1 referred to coordinate axes made by the base and height1 psi -#b,ralphabetagamma_/h -,ry7h - y7 - #cx_/h 7#h7 psi psi - ,r 7#a_/c;h - y7 x -,r h #a_/c hy h7 7x - y7 - #cxy y _/h 7#i7 and over the base y #j1 dx_/dnu -dx_/dy ,r7#a_/c h - #cx7_/h1 psi -,r7#a_/i h x74 7#aj7 ,integrating over the base1 to obtain one-third of the kinetic energy ,t1 _/ h_/root#c #a_/c ,t rho ,r7#cx#d - #a_/bg h#d7 dx_/h _/ -h_/root#c rho,rh#d_/aceroot#c 7#aa7 so that the effective k of the liquid filling the triangle is given by k ,t_/rho,r,a #b;h_/#de #b_/e 7radius of the inscribed circle71 7#ab7 or two-fifths of the k for the solid triangle4 ,again1 since dphi_/dnu dpsi_/ds1 dphi_/ds -dpsi_/dnu1 7#ac7 _/ _/ ,t rho phi dpsi -rho psi dphi4 7#ad7 _/ _/ ,with the ,stokes' function psi for motion symmetrical about an axis4 _/ dpsi _/ ,t rho phi ------ #bpiy ds pirho phi dpsi4 7#ae7 _/ yds _/ #cg4 ,flow1 ,circulation1 and ,vortex ,motion4--,the line integral of the tangential velocity along a curve from one point to another1 defined by _/ _/ dx dy dz _/ 7 u-- v-- w-- 7 ds 7u dx v dy z dz71 7#a7 _/ ds ds ds _/ _/ is called the flux along the curve from the first to the second point2 and if the curve closes in on itself the line integral round the curve is called the circulation in the curve4 ,with a velocity function phi1 the flow _/ - dphi phi#a - phi#b1 7#b7 _/ so that the flow is independent of the curve for all curves mutually reconcilable2 and the circulation round a closed curve is zero1 if the curve can be reduced to a point without leaving a region for which phi is single valued4 ,if through every point of a small closed curve the vortex lines are drawn1 a tube is obtained1 and the fluid contained is called a vortex filament4 ,by analogy with the spin of a rigid body1 the component spin of the fluid in any plane at a point is defined as the circulation round a small area in the plane enclosing the point1 divided by twice the area4 ,for in a rigid body1 rotating about ,oz with angular velocity zeta1 the circulation round a curve in the plane xy is _/ _/ dy dx zeta 7 x -- - y -- 7 ds zeta times twice the area4 7#c7 _/ ds ds _/ ,in a fluid1 the circulation round an elementary area dxdy is equal to _/ dv _/ du _/ dv du udx 7 v --dx 7dy - 7 u --dy 7dx - vdy 7 -- - -- 7dx dy1 7#d7 dx _/ dy _/ dx dy _/ so that the component spin is _/ dv du 7 -- - -- 7 zeta1 7#e7 dx dy _/ in the previous notation of #bd2 so also for the other two components xi and eta4 ,since the circulation round any triangular area of given aspect is the sum of the circulation round the projections of the area on the coordinate planes1 the composition of the components of spin1 xi1 eta1 zeta1 is according to the vector law4 ,hence in any infinitesimal part of the fluid the circulation is zero round every small plane curve passing through the vortex line2 and consequently the circulation round any curve drawn on the surface of a vortex filament is zero4 ,if at any two points of a vortex line the cross-section ,,abc1 ,a,b,c is drawn of the vortex filament1 joined by the vortex line ,,aa1 then1 since the flow in ,,aa is taken in opposite directions in the complete circuit ,,abc ,,aa,b,c ,a,a1 the resultant flow in ,,aa cancels1 and the circulation in ,,abc1 ,a,b,c is the same2 this is expressed by saying that at all points of a vortex filament omegaalpha is constant where alpha is the cross-section of the filament and omega the resultant spin 7,w4 ,k4 ,clifford1 ,kinematic1 book iii474 ,so far these theorems on vortex motion are kinematical2 but introducing the equations of motion of #bb1 ,du d,q ,dv d,q ,dw d,q -- -- #j1 -- -- #j1 -- -- #j1 7#f7 dt dx dt dy dt dz _/ ,q dp_/rho ,v1 7#g7 _/ and taking dx1 dy1 dz in the direction of u1 v1 w1 and dx 3 dy 3 dz u 3 v 3 w1 ,d _/ ,du ,d dx -- 7u dx v dy w dz 7 -- dx u ---- 444 -d,q dq1 7#h7 dt _/ dt dt and integrating round a closed curve ,d _/ -- 7u dx v dy w dz7 #j1 7#i7 dt _/ and the circulation in any circuit composed of the same fluid particles is constant2 and if the motion is differential irrotational and due to a velocity function1 the circulation is zero round all reconcilable paths4 ,interpreted dynamically the normal pressure of the surrounding fluid on a tube cannot create any circulation in the tube4 ,the circulation being always zero round a small plane curve passing through the axis of spin in vortical motion1 it follows conversely that a vortex filament is composed always of the same fluid particles2 and since the circulation round a cross-section of a vortex filament is constant1 not changing with the time1 it follows from the previous kinematical theorem that alphaomega is constant for all time1 and the same for every cross-section of the vortex filament4 ,a vortex filament must close on itself1 or end on a bounding surface1 as seen when the tip of a spoon is drawn through the surface of water4 ,denoting the cross-section alpha of a filament by d,s and its mass by dm1 the quantity omegad,s_/dm is called the vorticity2 this is the same at all points of a filament1 and it does not change during the motion2 and the vorticity is given by omega cosepsilond,s_/dm1 if d,s is the oblique section of which the normal makes an angle epsilon with the filament1 while the aggregate vorticity of a mass ,m inside a surface ,s is _/ ,m7-#a7 omega cos epsilon d,s4 _/ ,employing the equation of continuity when the liquid is homogeneous1 _/ dzeta deta d d d #b7 ------ - ------ 7 nablau1 444 1 nabla - --- - --- - ---1 7#aj7 dy dz _/ dx dy dz which is expressed by nabla7u1v1w7 #b curl 7xi1 eta1 zeta71 7xi1 eta1 zeta7 curl 7u1 v1 w74 7#aa7 #ch4 ,moving ,axes in ,hydrodynamics4--,in many problems1 such as the motion of a solid in liquid1 it is convenient to take coordinate axes fixed to the solid and moving with it as the movable trihedron frame of reference4 ,the components of velocity of the moving origin are denoted by ,u1 ,v1 ,w1 and the components of angular velocity of the frame of reference by ,p1 ,q1 ,r2 and then if u1 v1 w denote the components of fluid velocity in space1 and u1 v1 w the components relative to the axes at a point 7x1 y1 z7 fixed to the frame of reference1 we have u ,u u - y,r z,q1 7#a7 v ,v v- z,p x,r1 w ,w w - x,q y,p4 ,now if k denotes the component of absolute velocity in a direction fixed in space whose direction cosines are l1 m1 n1 k lu mv nw2 7#b7 and in the infinitesimal element of time dt1 the coordinates of the fluid particle at 7x1 y1 z7 will have changed by 7u1 v1 w7dt2 so that ,dk dl dm dn -- --u --v --w dt dt dt dt _/ du du du du l7 -- u-- v-- w-- 7 dt dx dy dz _/ _/ dv dv dv dv m7 -- u-- v-- w-- 7 dt dx dy dz _/ _/ dw dw dw dw n7 -- u-- v-- w-- 74 7#c7 dt dx dy dz _/ ,but as l1 m1 n are the direction cosines of a line fixed in space1 dl dm dn -- m,r - n,q1 -- n,p - l,r1 -- l,q - m,p2 7#d7 dt dt dt so that ,dk _/ du du du du -- l7 -- - v,r w,q u-- v-- w-- 7 m74447 n74447 dt dt dx dy dz _/ _/ #a dp _/ #a dp _/ #a dp l7 ,x- --- -- 7 m7 ,y - --- -- 7 n7 ,z - --- -- 71 7#e7 p dx _/ p dy _/ p dz _/ for all values of l1 m1 n1 leading to the equations of motion with moving axes4 ,when the motion is such that dphi dpsi dphi dpsi dphi dpsi u - ------ - m------1 v - ------ - m------1 w - ------ - m------1 7#f7 dx dx dy dy dz dz as in #be 7#a71 a first integral of the equations in 7#e7 may be written _/ dp dphi dpsi _/ dphi dpsi ----- ,v q - ------ - m------ 7u - u7 7 ------ m------ 7 _/ rho dt dt dx dx _/ _/ dphi dpsi _/ dphi dpsi 7v - v77 ------ m------ 7 7w - w77 ------ m------ 7 ,f7t71 7#g7 dy dy _/ dz dz _/ in which dphi dphi dphi dphi ------ - 7u - u7------ - 7v -v7------ - 7w - w7------ dt dx dy dz dphi dphi dphi dphi ------ - 7,u - y,r z,q7------ - 7,v - z,p x,r7------ - 7,w - x,q y,p7------ 7#h7 dt dx dy dz is the time-rate of change of phi at a point fixed in space1 which is left behind with velocity components u - u1 v - v1 w - w4 ,in the case of a steady motion of homogeneous liquid symmetrical about ,ox1 where ,o is advancing with velocity ,u1 the equation 7#e7 of #cd p_/rho ,v q - f7psi7 constant 7#i7 becomes transformed into p ,u dpsi ----- ,v q - --- ------ ,u - f7psi ,uy7 constant1 7#aj7 rho y dy psi psi ,u1 7#aa7 subject to the condition1 from 7#d7 #cd1 y7-#b7nablapsi -f7psi71 y7-#b7nablapsi -f7psi ,uy74 7#ab7 ,thus1 for example1 with psi ,uy7ra7-#b7 - #a71 r x y1 7#ac7 for the space inside the sphere r a1 compared with the value of psi in #cd 7#ac7 for the space outside1 there is no discontinuity of the velocity in crossing the surface4 ,inside the sphere d _/ #a dpsi d _/ #a dpsi #ae y #bzeta --- 7 --- ------- 7 --- 7 --- ------- 7 ---,u ---1 7#ad7 dx y dx _/ dy y dy _/ #b a so that #cd 7#d7 is satisfied1 with #ae #ae f7psi7 ---,ua7-#b71 f7psi7 ---,upsia7-#b72 7#ae7 #b #b and 7#aj7 reduces to p #i _/ x _/ y ----- ,v - ---,u 7 --- -#a 7 - 7 --- - 7 constant2 7#af7 rho #h a _/ a _/ this gives the state of motion in ,m4 ,j4 ,m4 ,hill's spherical vortex1 advancing through the surrounding liquid with uniform velocity4 #ci4 ,as an application of moving axes1 consider the motion of liquid filling the ellipsoidal case x y z --- --- --- #a2 7#a7 a b c and first suppose the liquid to be frozen1 and the ellipsoid to be rotating about the centre with components of angular velocity xi1 eta1 zeta2 then u - yzeta zeta1 v - zxi xzeta1 w - xeta yxi4 7#b7 ,now suppose the liquid to be melted1 and additional components of angular velocity ,omega#a1 ,omega#b1 ,omega#c communicated to the ellipsoidal case2 the additional velocity communicated to the liquid will be due to a velocity-function b - c c - a a - b phi - ,omega#a ------- yz - ,omega#b -------zx - ,omega#c -------xy1 7#c7 b c c a a b as may be verified by considering one term at a time4 ,if u1 v1 w denote the components of the velocity of the liquid relative to the axes1 #b;a #b;a u u y,r - z,q ------- ,omega#c y - ------- ,omega#b z1 7#d7 a b c a #b;b #b;b v v z,p - x,r ------- ,omega#a z - ------- ,omega#c x1 7#e7 b c a b #b;c #b;c w w x,q - y,p ------- ,omega#b x - ------- ,omega#a y1 7#f7 c a b c ,p ,omega#a xi1 ,q ,omega#b eta1 ,r ,omega#c zeta4 7#g7 ,thus x y z u --- v --- w --- #j1 7#h7 a#b b#b c#b so that a liquid particle remains always on a similar ellipsoid4 ,the hydrodynamical equations with moving axes1 taking into account the mutual gravitation of the liquid1 become #a dp du du du du ----- -- #dpirho,ax -- - v,r w,q u-- v-- w-- #j1 444 1 444 1 7#i7 rho dx dt dx dy dz where _/ oo abcdlambda ,a1 ,b1 ,c ---------------------------------------- ------ _/ #j 7a lambda1 b lambda1 c lambda7,p ,p #d7;a lambda7 7b lambda7 7c lambda74 7#aj7 ,with the values above of u1 v1 w1 u1 v1 w1 the equations become of the form #a dp ----- -- #dpirho,ax alphax hy gz #j1 7#aa7 rho dx #a dp ----- -- #dpirho,by hx betay fz #j1 7#ab7 rho dy #a dp ----- -- #dpirho,cz gx fy gammaz #j1 7#ac7 rho dz and integrating prho7-#a7 #bpirho7,ax ,by ,cz7 7alphax betay gammaz #b;fyz #b;gzx #b;hxy7 const41 7#ad7 so that the surfaces of equal pressure are similar quadric surfaces1 which1 symmetry and dynamical considerations show1 must be coaxial surfaces2 and f1 g1 h vanish1 as follows also by algebraical reduction2 and #d;c7c - a7 _/ c - a alpha ------------,omega#b - 7 -------,omega#b - eta 7 7c a7 c a _/ #d;b7a - b7 _/ a - b - ------------,omega#c - 7 -------,omega#c - zeta 71 7#ae7 7a b7 a b _/ with similar equations for beta and gamma4 ,if we can make 7#dpirho,a alpha7x 7#dpirho,b beta7b 7#dpirho,c gamma7c1 7#af7 the surfaces of equal pressure are similar to the external case1 which can then be removed without affecting the motion1 provided alpha1 beta1 gamma remain constant4 ,this is so when the axis of revolution is a principal axis1 say ,oz2 when ,omega#a #j1 ,omega#b #j1 xi #j1 eta #j4 7#ag7 ,if ,omega#c #j or theta#c zeta in addition1 we obtain the solution of ,jacobi's ellipsoid of liquid of three unequal axes1 rotating bodily about the least axis2 and putting a b1 ,maclaurin's solution is obtained of the rotating spheroid4 ,in the general motion again of the liquid filling a case1 when a b1 ,omega#c may be replaced by zero1 and the equations1 hydrodynamical and dynamical1 reduce to dxi #b;c deta #b;a ----- - -------,omega#b zeta1 ------ -------,omega#a zeta1 dt a c dt a c dzeta #b;c ------- -------7,omega#b xi - ,omega#b eta7 7#ah7 dt a c d,omega#a a c --------- ,omega#b zeta -------etazeta1 dt a - c d,omega#b a c --------- ,omega#a zeta -------xizeta2 7#ai7 dt a - c of which three integrals are a xi eta ,l - --zeta1 7#bj7 c 7a c7 ,omega#a ,omega#b ,m ------------ zeta1 7#ba7 #b;c7a - c7 a c ,omega#a xi ,omega#b eta,n ------- zeta2 7#bb7 #d;c and then _/ dzeta #d;c#d 7 ------- 7 --------- 7,omega#bxi - ,omega#a;eta7 dt _/ 7a c7 #d;c#d ---------- 7xi eta77,omega7#a ,omega#b7 -7,omega#axi ,omega#b;eta7 7a c7 #d;c#d _/ 7a c7 a 7a c7 ---------- ,,lm - ,n 7 ,l------------ - ,m --- - ,n --------- 7 zeta 7a c7 #b;c7a c7 c #b;c _/ 7a c77#i;a - c7 - ------------------- zeta#d ,z1 7#bc7 #af;c#d7;a - c7 where ,z is a quadratic in zeta1 so that zeta is an elliptic function of t1 except when c a1 or #c;a4 ,put ,omega#a ,omega cos phi1 ,omega#b -,omega sin phi1 dphi d,omega#a d,omega#b 7a c7 ,omega#b ------ -----------,omega#b - ,omega#a --------- ,omegazeta - ---------7,omega#a xi ,omega#b eta7zeta1 7#bd7 dt dt dt 7a - c7 a c ,n ------- dphi 7a c7 #d;c ------ zeta - --------- -------------------------1 7#be7 dt 7a - c7 7a c7 ,m ------------zeta #b;c7a - c7 a c ,n -------zeta _/ zetad a c _/ #d;c zeta dzeta phi ------- - ------- ------------------------ --------------1 7#bf7 _/ root,z a - c _/ 7a c7 root,z ,m ------------zeta #b;c7a - c7 which1 as ,z is a quadratic function of zeta1 are non-elliptic integrals2 so also for psi1 where xi omega cos psi1 eta -omega sin psi4 ,in a state of steady motion dzeta ,omega#a ,omega#b ------- #j1 -------- --------1 7#bg7 dt xi eta phi psi nt1 suppose1 7#bh7 ,omega#axi ,omega#b eta ,omegaomega1 7#bi7 dphi a c omega ------ zeta- ------- -------zeta1 7#cj7 dt a - c ,omega dpsi #b;a ,omega ------ - ------- -------zeta1 7#ca7 dt a c omega a c omega #b;a ,omega #a - ------- ------- - ------- -------1 7#cb7 a - c ,omega a c omega _/ omega a c 7a - c77#i;a - c7 7 ------- - ------- 7 -------------------1 7#cc7 ,omega a - c _/ #d7;a c7 and a state of steady motion is impossible when #c;a c a4 ,an experiment was devised by ,lord ,kelvin for demonstrating this1 in which the difference of steadiness was shown of a copper shell filled with liquid and spun gyroscopically1 according as the shell was slightly oblate or prolate4 ,according to the theory above the stability is regained when the length is more than three diameters1 so that a modern projectile with a cavity more than three diameters long should fly steadily when filled with water2 while the old-fashioned type1 not so elongated1 would be highly unsteady2 and for the same reason the gas bags of a dirigible balloon should be over rather than under three diameters long4 #dj4 ,a ,liquid ,jet4--,by the use of the complex variable and its conjugate functions1 an attempt can be made to give a mathematical interpretation of problems such as the efflux of water in a jet or of smoke from a chimney1 the discharge through a weir1 the flow of water through the piers of a bridge1 or past the side of a ship1 the wind blowing on a sail or aeroplane1 or against a wall1 or impinging jets of gas or water2 cases where a surface of discontinuity is observable1 more or less distinct1 which separates the running stream from the dead water or air4 ,uniplanar motion alone is so far amenable to analysis2 the velocity function phi and stream function psi are given as conjugate functions of the coordinates x1 y by w f7z7 where z x yi1 w phi psii1 7#a7 and then dw dphi dpsi -- ------ i------ -u vi2 7#b7 dz dx dx so that1 with u q cos theta1 v q sin theta1 the function dz ,q ,q ,q zeta -,q -- -------- ---7u vi7 --- 7cos theta i sin theta71 7#c7 dw 7u - vi7 q q gives zeta as a vector representing the reciprocal of the velocity q in direction and magnitude1 in terms of some standard velocity ,q4 ,to determine the motion of a jet which issues from a vessel with plane walls1 the vector zeta must be ,constructed so as to have a constant direction theta along a plane boundary1 and to give a constant skin velocity over the surface of a jet1 where the pressure is constant4 ,it is convenient to introduce the function ,omega log zeta log7,q_/q7 thetai 7#d7 so that the polygon representing ,omega conformally has a boundary given by straight lines parallel to the coordinate axes2 and then to determine ,omega and w as functions of a variable u 7not to be confused with the velocity component of q71 such that in the conformal representation the boundary of the ,omega and w polygon is made to coincide with the real axis of u4 ,illustration3 ,,fig4 #d4 ,it will be sufficient to give a few illustrations4 ,consider the motion where the liquid is coming from an infinite distance between two parallel walls at a distance xx 7fig4 #d71 and issues in a jet between two edges ,a and ,a2 the wall x,a being bent at a corner ,b1 with the external angle beta pi_/n4 ,the theory of conformal representation shows that the motion is given by root7b - au - a7 root7b - au - a7 #a_/n zeta ---------------------------------------- --- 1 u ae7-piw_/m72 7#e7 root7a - au - b7 where u a1 a at the edge ,a1 ,a2 u b at a corner ,b2 u #j across xx where phi oo2 and u oo1 phi oo across the end ,,jj of the jet1 bounded by the curved lines ,,apj1 ,a,p,j1 over which the skin velocity is ,q4 ,the stream lines x,b,a,j1 x,a,j are given by psi #j1 m2 so that if c denotes the ultimate breadth ,,jj of the jet1 where the velocity may be supposed uniform and equal to the skin velocity ,q1 m ,qc1 c m_/,q4 ,if there are more ,b corners than one1 either on x,a or x,a1 the expression for zeta is the product of corresponding factors1 such as in 7#e74 ,restricting the attention to a single corner ,b1 _/ ,q n root7b - au - a7 root7b - au - a7 zetan 7 --- 7 7cos ntheta i sin ntheta ---------------------------------------- ---1 7#f7 q _/ root7a - a4u - b7 _/ ,q n _/ ,q n ch nomega ch log7 --- 7 cos ntheta i sh log 7 --- 7 sin ntheta q _/ q _/ _/b - a _/u - a 7zetan zeta7-n77 _/ ------ _/ ------ 7#g7 _/ a - a _/ u - b _/ ,q _/ ,q n sh n,omega sh log 7 --- 7 cos ntheta i ch log 7 --- 7 sin ntheta q _/ q _/ _/b - a _/u - a 7zetan - zeta7-n77 _/ ------ _/ ------ 7#h7 _/ a - a _/ u - b oo a b #j a -oo 7#i7 and then d,omega #a root7b - ab - a7 dw m -------- - -- ---------------------------1 -- - ------ 7#aj7 du #bn 7u - b7root7a - au - a7 du piu the formulas by which the conformal representation is obtained4 ,for the ,omega polygon has a right angle at u a1 a1 and a zero angle at u b1 where theta changes from #j to pi_/n and ,omega increases by ipi_/n2 so that d,omega ,a root7b - ab - a7 -------- ---------------------------1 where ,a --------------------4 7#aa7 du 7u - b7root7u - au - a7 #bn ,and the w polygon has a zero angle at u #j1 oo1 where psi changes from #j to m and back again1 so that w changes by im1 and dw ,b m -- ---1 where ,b - ----4 7#ab7 du u pi ,along the stream line x,b,a,p,j1 psi #j1 u ae7-piphi_/m72 7#ac7 and over the jet surface ,,jpa1 where the skin velocity is ,q1 dphi ------ -q -,q1 u ae7pis,q_/m7 ae7pis_/c71 7#ad7 ds denoting the arc ,,ap by s1 starting at u a2 _/b - a _/u - a ch n,omega cos ntheta _/ ----- _/ ------ 7#ae7 _/ a - a _/ u - b _/a - b _/u - a sh n,omega i sin ntheta i _/ ------ _/ ------ 7#af7 _/ a - a _/ u - b oo u ae7pis_/c7 a1 7#ag7 and this gives the intrinsic equation of the jet1 and then the radius of curvature ds #a dphi i dw i dw _/ d,omega rho - -------- --- -------- --- ------- --- -- _/ ------- dtheta ,q dtheta ,q d,omega ,q du _/ du c u - b root7u - au - a7 ----#bn----- --------------------1 7#ah7 pi u root7a - bb - a7 not requiring the integration of 7#aa7 and 7#ab7 ,if theta alpha across the end ,,jj of the jet1 where u oo1 q ,q1 _/b - a _/a - b ch n,omega cos nalpha _/-------1 sh n,omega i sin nalpha _/ ------1 7#ai7 _/ a - a _/ a - a ,then a - bb - a a - a cos #bnalpha - cos #bntheta #b------------ sin #bnalpha------ a - au - b u - b root7a - b4b - a7root7u - au - b7 sin #bntheta #b-------------------------------------- -- 7#bj7 a - au - b root7a - ab - a7 sin #bnalpha--------------------2 u - b #bn c _/ b root7a - bb - a7 ----- ----- 7 #a ----- 7 -------------------- 7#ba7 phi rho u - b_/ root7u - au - a7 a - a 7a a7 cos #bnalpha - a a 7a - a7 cos #bnalpha cos #bntheta ---------------------------------------- ---------------------------------------- 7a - a7 sin #bnalpha cos #bnalpha - cos #bntheta ----------------------------- sin #bntheta ,along the wall ,,ab1 cos ntheta #j1 sin ntheta #a1 a u b1 7#bb7 _/ ,q n _/b - a _/a - u ch n,omega i sh log 7 --- 7 i _/ ------ _/ ------ 7#bc7 q _/ _/ a - a _/ u - b _/ ,q n _/a - b _/u - a sh n,omega i ch log 7 --- 7 i _/ ------ _/ ------ 7#bd7 q _/ _/ a - a _/ u - b ds ds dphi m c ,q -- ------ ------ ------ --- -- 7#be7 du dphi dt piqu pi qu ,,ab _/ a ,q du pi-- --- -- c _/ b q u _/ root7a - b7root7u - a7 root7b - a7root7a - u7 #a_/n du ---------------------------------------- ----------------- --4 7#bf7 _/ root7a - a7root7u - b7 u ,along the wall ,bx1 cos ntheta #a1 sin ntheta #j1 b u #j 7#bg7 _/ ,q n _/b - a _/a - u ch n,omega ch log 7 --- 7 _/ ------ _/ ------ 7#bh7 q _/ _/ a - a _/ b - u _/ ,q n _/a - b _/u - a sh n,omega sh log 7 --- 7 _/ ------ _/ ------4 7#bi7 q _/ _/ a - a _/ b - u ,at x where phi oo1 u #j1 and q q#j1 _/ ,q n _/b - a _/ a _/a - b _/ -a 7 --- 7 _/ ------ _/ --- _/ ------ _/ ---4 7#cj7 q#j _/ _/ a - a _/ b _/ a - a _/ q ,in crossing to the line of flow x,a,p,j1 psi changes from #j to m1 so that with q ,q across ,,jj1 while across xx the velocity is q#j1 so that m q#j4xx ,q4,,jj 7#ca7 ,,jj q#j _/b - a _/ a _/a - b _/ -a #a_/n -- --- _/ ------ _/ --- - _/ ------ _/ --- 1 7#cb7 xx ,q _/ a - a _/ b _/ a - a _/ q giving the contraction of the jet compared with the initial breadth of the stream4 ,along the line of flow x,a,p,j1 psi m1 u ae7-piphi_/m71 and from x to ,a1 cos ntheta #a1 sin ntheta #j1 _/ ,q n _/b - a _/a - u ch n,omega ch log 7 --- 7 _/ ------ _/ ------1 7#cc7 q _/ _/ a - a _/ b - u _/ ,q n _/a - b _/u - a sh n,omega sh log 7 --- 7 _/ ------ _/ ------4 7#cd7 q _/ _/ a - a _/ b - u #j u a4 7#ce7 ,along the jet surface ,a,j1 q ,q1 _/b - a _/a - u ch n,omega cos ntheta _/ ------ _/ ------1 7#cf7 _/ a - a _/ b - u _/a - b _/a - u sh n,omega i sin ntheta i _/ ------ _/ ------1 7#cg7 _/ a - a _/ b - u a u ae7pi_/sc7 -oo1 7#ch7 giving the intrinsic equation4 #da4 ,the first problem of this kind1 worked out by ,h4 v4 ,helmholtz1 of the efflux of a jet between two edges ,a and ,a#a in an infinite wall1 is obtained by the symmetrical duplication of the above1 with n #a1 b #j1 a -oo1 as in fig4 #e1 _/u - a _/ -a ch ,omega _/ -----1 sh ,omega _/ ---2 7#a7 _/ u _/ u and along the jet ,,apj1 oo u ae7pis_/c7 a1 sh ,omega i sin theta - iroot7a_/u7 ie7-pis_/c71 7#b7 _/ oo _/ c c ,,pm sin theta ds e7-pis_/c7 ds ----- e7-pis_/c7 ----- sin theta1 7#c7 _/ s _/ pi pi so that ,,pt c_/pi1 and the curve ,,ap is the tractrix2 and the coefficient of contraction1 or breadth of the jet pi ---------------------- --------4 7#d7 breadth of the orifice pi #b ,a change of ,omega and theta into n,omega and ntheta will give the solution for two walls converging symmetrically to the orifice ,,aa#a at an angle pi_/n4 ,with n 1 the reentrant walls are given of ,borda's mouthpiece1 and the coefficient of contraction becomes 4 ,generally1 by making a - oo1 the line x,a may be taken as a straight stream line of infinite length1 forming an axis of symmetry2 and then by duplication the result can be obtained1 with assigned n1 a1 and b1 of the efflux from a symmetrical converging mouthpiece1 or of the flow of water through the arches of a bridge1 with wedge-shaped piers to divide the stream4 ,illustration3 ,,fig4 #e4 ,illustration3 ,,fig4 #f4 #db4 ,other arrangements of the constants n1 a1 b1 a will give the results of special problems considered by ,j4 ,m4 ,michell1 ,phil4 ,trans4 #ahij4 ,thus with a #j1 a stream is split symmetrically by a wedge of angle pi_/n as in ,bobyleff's problem2 and1 by making a oo1 the wedge extends to infinity2 then _/ b _/ n ch n,omega _/ -----1 sh n,omega _/ -----4 7#a7 _/ b - u _/ b - u ,over the jet surface psi m1 q ,q1 u - e7piphi_/m7 - be7pi_/c71 _/ #a _/ e7pi_/c7 ch ,omega cos ntheta _/ ---------------1 sh ,omega i sin ntheta i _/ ---------------1 7#b7 _/ e7pi_/c7 #a _/ e7pi_/c7 #a pi ds #bn e7pi_/c7 tan ntheta1 ----- -------- -------------4 7#c7 c dtheta sin #bntheta ,for a jet impinging normally on an infinite plane1 as in fig4 #f1 n #a1 e7pi_/c7 tan theta1 ch 7pis_/c7 sin #btheta #a1 7#d7 sh pix_/c cot theta1 sh piy_/c tan theta1 sh pix_/c sh piy_/c #a1 e7pi7x y7_/c7 e7pix_/c7 e7piy_/c7 #a4 7#e7 ,with n 1 the jet is reversed in direction1 and the profile is the catenary of equal strength4 ,in ,bobyleff's problem of the wedge of finite breadth1 _/ b _/u - a _/b - a _/ u ch n,omega _/ --- _/ -----1 sh n,omega _/ ----- _/ -----1 7#f7 _/ a _/ u - b _/ a _/ u - b _/ b _/a - b cos nalpha _/ ---1 sin nalpha _/ -----1 7#g7 _/ a _/ a and along the free surface ,,apj1 q ,q1 psi #j1 u e7-piphi_/m7 ae7pis_/c71 _/ e7pi_/c7 - #a cos ntheta cos nalpha _/ ---------------------------1 _/ e7pi_/c7 - cos nalpha cos nalpha sin ntheta e7pi_/c7 -----------------------------1 7#h7 sin ntheta - sin nalpha the intrinsic equation1 the other free surface ,a,p,j being given by cos nalpha sin ntheta e7pi_/c7 -----------------------------4 7#i7 sin nalpha - sin ntheta ,putting n #a gives the case of a stream of finite breadth disturbed by a transverse plane1 a particular case of ,fig4 #g4 ,when a b1 alpha #j1 and the stream is very broad compared with the wedge or lamina2 so1 putting w w7a - b7_/a in the penultimate case1 and u ae7-w7 asympt a - 7a - b7w1 7#aj7 _/w #a _/ #a ch n,omega _/ ------1 sh n,omega _/ --------1 7#aa7 _/ w _/ rootw in which we may write w phi psii4 7#ab7 ,along the stream line x,a,b,p,j1 psi #j2 and along the jet surface ,,apj1 -#a phi -oo2 and putting phi -pis_/c - #a1 the intrinsic equation is pis_/c cot ntheta1 7#ac7 which for n #a is the evolute of a catenary4 ,illustration3 ,,fig4 #g4 #dc4 ,when the barrier ,,aa is held oblique to the current1 the stream line x,b is curved to the branch point ,b on ,,aa 7fig4 #g71 and so must be excluded from the boundary of u2 the conformal representation is made now with d,omega root7b - ab - a7 -------- - ---------------------------- 7#a7 du 7u - b7 root7u - au - a7 dw m #a m #a m m u - b -- - ---- ----- - ---- -----1 - ------ -------------1 du pi u - j pi u - j pi u - ju - j mj mj b ---------1 7#b7 m m taking u oo at the source where phi oo1 u b at the branch point ,b1 u j1 j at the end of the two diverging streams where phi -oo2 while psi #j along the stream line which divides at ,b and passes through ,a1 ,a2 and psi m1 -m along the outside boundaries1 so that m_/,q1 m_/,q is the final breadth of the jets1 and 7m m7_/,q is the initial breadth1 c#a of the impinging stream4 ,then _/b - a _/u - a _/b - a _/u - a ch ,omega _/ ------ _/ -----1 sh ,omega _/ ------ _/ ------1 7#c7 _/ a - a _/ u - b _/ a - a _/ u - b #b;b - a - a ,n ch ,omega ----------- - -----1 a - a u - b _/ root7#b;a - uu - a7 sh ,omega _/ ,n----------------------1 _/ u - b a - bb - a ,n #b------------4 7#d7 a - a ,along a jet surface1 q ,q1 and ch,omega cos theta cos alpha - sin alpha7a - a7_/7u - b71 7#e7 if theta alpha at the source x of the jet x,b1 where u oo2 and supposing theta beta1 beta at the end of the streams where u j1 j1 u - b sin alpha u - j costheta - cosbeta ----- -------------------------1 ------ sin alpha----------------------------------- ------------------1 a - a cos alpha - cos theta a - a 7cos alpha - cos beta77cos alpha - cos theta7 u - j cos theta - cos beta ----- sin alpha----------------------------------- -------------------2 7#f7 a - a 7cos alpha - cos beta77cos alpha - cos theta7 and psi being constant along a stream line dphi dw ds dphi dw du ------ --1 ,q -------- -------- -- --------1 du du dtheta dtheta du dtheta pi,q ds pi ds 7cos alpha - cos beta77cos alpha - cos beta7sintheta ------ -------- ---- -------- ---------------------------------------- ---------------------------------------- -1 m m dtheta c dtheta 7cos alpha - cos theta77cos theta - cos beta77cos theta - cos alpha7 sin theta cos alpha - cos beta sin theta ------------------------- ------------------------- ------------------------ cos alpha - cos theta cos beta - cos beta cos theta - cos beta cos alpha - cos beta sin theta ------------------------ -------------------------1 7#g7 cos beta - cos beta cos theta - cos beta giving the intrinsic1 equation of the surface of a jet1 with proper attention to the sign4 ,from ,a to ,b1 a u b1 theta #j1 ,q a - a ch ,omega ch log --- cos alpha - sin alpha ------ q a - b ,q root7a - uu - a7 sh ,omega sh log --- -------------------- sin alpha q u - b ,q 7u - b7 cos alpha - 7a - a7 sin alpha root7a - uu - a7sinalpha --- ---------------------------------------- ------------------------------------- 7#h7 q u - b ds ds dphi ,q dw ,q -- ,q ------ ------ - --- -- du dphi du q du m m 7u - b7 cos alpha - 7a - a7 sin alpha root7a - uu - a7 sin alpha ------ ---------------------------------------- --------------------------------------- 7#i7 pi j - uu - j ,,ab _/ a 7#b;b - a - a77u - b7 - #b7;a - b77b - a7 #broot7a - bb -aa - uu -a7 pi-- ---------------------------------------- ---------------------------------- du1 7#aj7 c _/ b a - aj - uu - j with a similar expression for ,,ba4 ,the motion of a jet impinging on an infinite barrier is obtained by putting j a1 j a2 duplicated on the other side of the barrier1 the motion reversed will represent the direct collision of two jets of unequal breadth and equal velocity4 ,when the barrier is small compared with the jet1 alpha beta beta1 and ,g4 ,kirchhoff's solution is obtained of a barrier placed obliquely in an infinite stream4 ,two corners ,b#a and ,b#b in the wall x,a1 with a -oo1 and n #a1 will give the solution1 by duplication1 of a jet issuing by a reentrant mouthpiece placed symmetrically in the end wall of the channel2 or else of the channel blocked partially by a diaphragm across the middle1 with edges turned back symmetrically1 problems discussed by ,j4 ,h4 ,michell1 ,a4 ,e4 ,h4 ,love and ,m4 ,rthy4 ,when the polygon is closed by the walls joining1 instead of reaching back to infinity at xx1 the liquid motion must be due to a source1 and this modification has been worked out by ,b4 ,hopkinson in the ,proc4 ,lond4 ,math4 ,soc41 #ahih4 ,michell has discussed also the hollow vortex stationary inside a polygon 7,phil4 ,trans41 #ahij72 the solution is given by ch n,omega sn w1 sh n,omega i cn w 7#aa7 so that1 round the boundary of the polygon1 psi ,k1 sin ntheta #j2 and on the surface of the vortex psi #j1 q ,q1 and cos ntheta sn phi1 ntheta pi - am s_/c1 7#ab7 the intrinsic equation of the curve4 ,this is a closed ,sumner line for n #a1 when the boundary consists of two parallel walls2 and n gives an ,elastica4 #dd4 ,the ,motion of a ,solid through a ,liquid4--,an important problem in the motion of a liquid is the determination of the state of velocity set up by the passage of a solid through it2 and thence of the pressure and reaction of the liquid on the surface of the solid1 by which its motion is influenced when it is free4 ,beginning with a single body in liquid extending to infinity1 and denoting by ,u1 ,v1 ,w1 ,p1 ,q1 ,r the components of linear and angular velocity with respect to axes fixed in the body1 the velocity function takes the form phi ,uphi#a ,vphi#b ,wphi#c ,pchi#a ,qchi#b ,rchi#c1 7#a7 where the phi's and chi's are functions of x1 y1 z1 depending on the shape of the body2 interpreted dynamically1 ,c - rhophi represents the impulsive pressure required to stop the motion1 or ,c rhophi to start it again from rest4 ,the terms of phi may be determined one at a time1 and this problem is purely kinematical2 thus to determine phi#a1 the component ,u alone is taken to exist1 and then l1 m1 n1 denoting the direction cosines of the normal of the surface drawn into the exterior liquid1 the function phi#a must be determined to satisfy the conditions 7i47 nablaphi#a #j4 throughout the liquid2 7ii47 dph#a_/;dupsilon -l1 the gradient of phi down the normal at the surface of the moving solid2 7iii47 dph#a_/;dupsilon #j1 over a fixed boundary1 or at infinity2 similarly for phi#b and phi#c4 ,to determine chi#a the angular velocity ,p alone is introduced1 and the conditions to be satisfied are 7i47 nablachi#a #j1 throughout the liquid2 7ii47 dchi#a_/;dupsilon mz - ny1 at the surface of the moving body1 but zero over a fixed surface1 and at infinity2 the same for chi#b and chi#c4 ,for a cavity filled with liquid in the interior of the body1 since the liquid inside moves bodily for a motion of translation only1 phi#a -x1 phi#b -y1 phi#c -z2 7#b7 but a rotation will stir up the liquid in the cavity1 so that the chi's depend on the shape of the surface4 ,the ellipsoid was the shape first worked out1 by ,george ,green1 in his ,research on the ,vibration of a ,pendulum in a ,fluid ,medium 7#ahcc72 the extension to any other surface will form an important step in this subject4 ,a system of confocal ellipsoids is taken x y z ------------- ------------- ------------- #a 7#c7 a lambda b lambda c lambda and a velocity function of the form phi xpsi1 7#d7 where psi is a function of lambda only1 so that psi is constant over an ellipsoid2 and we seek to determine the motion set up1 and the form of psi which will satisfy the equation of continuity4 ,over the ellipsoid1 p denoting the length of the perpendicular from the centre on a tangent plane1 px py pz l -------------1 m -------------1 n ------------- 7#e7 a lambda b lambda c lambda px py pz #a ---------------- ---------------- ----------------1 7#f7 7a lambda7 7b lambda7 7c lambda7 p 7a lambda7l 7b lambda7m 7c lambda7n1 7#g7 al bm cn lambda1 dp dlambda #bp-- ---------2 7#h7 ds ds ,thence dphi dx dpsi ------ --psi x------ ds ds ds dx dpsi dp --psi #b7;a lambda7--------- l--1 7#i7 ds dlambda ds so that the velocity of the liquid may be resolved into a component -psi parallel to ,ox1 and -#b7;a lambda7l dpsi_/dlambda along the normal of the ellipsoid2 and the liquid flows over an ellipsoid along a line of slope with respect to ,ox1 treated as the vertical4 ,along the normal itself dphi _/ dpsi ----- 7 psi #b7;a lambda7-------- 7l1 7#aj7 ds dlambda _/ so that over the surface of an ellipsoid where lambda and psi are constant1 the normal velocity is the same as that of the ellipsoid itself1 moving as a solid with velocity parallel to ,ox dpsi ,u -psi - #b7;a lambda7---------1 7#aa7 dlambda and so the boundary condition is satisfied2 moreover1 any ellipsoidal surface lambda may be supposed moving as if rigid with the velocity in 7#aa71 without disturbing the liquid motion for the moment4 ,the continuity is secured if the liquid between two ellipsoids lambda and lambda#a1 moving with the velocity ,u and ,u#a of equation 7#aa71 is squeezed out or sucked in across the plane x #j at a rate equal to the integral flow of the velocity psi across the annular area alpha#a - alpha of the two ellipsoids made by x #j2 or if _/ lambda#a dalpha alpha,u - alpha#a,u#a psi-------- dlambda1 7#ab7 _/ lambda dlambda alpha piroot7b lambdac lambda74 7#ac7 ,expressed as a differential relation1 with the value of ,u from 7#aa71 d dpsi dalpha --------- alphapsi #b7;a lambda7alpha--------- - psi--------- #j1 7#ad7 dlambda dlambda dlambda dpsi d _/ dpsi #c;alpha--------- #b7;a lambda7-------- 7 alpha-------- 7 #j1 7#ae7 dlambda dlambda dlambda_/ and integrating dpsi 7a lambda7#c_/b alpha-------- a constant1 7#af7 dlambda so that we may put _/ ,mdlambda psi ----------------1 7#ag7 _/ 7a lambda7,p ,p #d7;a lambda77b lambda77c lambda71 7#ah7 where ,m denotes a constant2 so that psi is an elliptic integral of the second kind4 ,the quiescent ellipsoidal surface1 over which the motion is entirely tangential1 is the one for which dpsi #b7;a lambda7--------- psi #j1 7#ai7 dlambda and this is the infinite boundary ellipsoid if we make the upper limit lambda#a oo4 ,the velocity of the ellipsoid defined by lambda #j is then dpsi#j ,u -#b;a--------- - psi#j dlambda ,m _/ oo ,mdlambda --- - ---------------- abc _/ #j 7a lambda7,p ,m --- 7#a - ,a#j71 7#bj7 abc with the notation _/ oo abc dlambda ,a or ,alambda ---------------- _/lambda 7a lambda7,p d _/ oo dlambda -#b;abc--- ---------1 7#ba7 da_/ lambda ,p so that in 7#d7 ,m ,ux,a x,alambda phi ---x,a ------1 phi#a -----------1 7#bb7 abc #a - ,a#j #a - ,a#j in 7#a7 for an ellipsoid4 ,the impulse required to set up the motion in liquid of density rho is the resultant of an impulsive pressure rhophi over the surface ,s of the ellipsoid1 and is therefore _/ _/ _/ _/ rhophil d,s rhopsi#j xl d,s _/_/ _/_/ rhopsi#j 7volume of the ellipsoid7 psi#j ,w1 7#bc7 where ,w denotes the weight of liquid displaced4 ,denoting the effective inertia of the liquid parallel to ,ox by alpha,w4 the momentum alpha,w,u psi#j,w 7#bd7 psi#j ,a#j alpha ------ ------2 7#be7 ,u #a - ,a#j in this way the air drag was calculated by ,green for an ellipsoidal pendulum4 ,similarly1 the inertia parallel to ,oy and ,oz is ,b#j ,c#j beta,w ------ ,w1 gamma,w ------ ,w1 7#bf7 #a - ,b#j #a - ,c#j _/ oo abc dlambda ,blambda1 ,clambda -------------------------------2 7#bg7 _/lambda 7b lambda1 c lambda7,p and ,a ,b ,c abc_/,p1 ,a#j ,b#j ,c#j #a4 7#bh7 ,for a sphere a b c1 ,a#j ,b#j ,c#j #a_/c1 alpha beta gamma 1 7#bi7 so that the effective inertia of a sphere is increased by half the weight of liquid displaced2 and in frictionless air or liquid the sphere1 of weight ,w1 will describe a parabola with vertical acceleration ,w - ,w ------- g4 7#cj7 ,w ,w ,thus a spherical air bubble1 in which ,w_/,w is insensible1 will begin to rise in water with acceleration #b;g4 #de4 ,when the liquid is bounded externally by the fixed ellipsoid lambda lambda#a1 a slight extension will give the velocity function phi of the liquid in the interspace as the ellipsoid lambda #j is passing with velocity ,u through the confocal position2 phi must now take the form x7psi ,n71 and will satisfy the conditions in the shape abc _/lambda#a abcdlambda ------ ---------------- ,a ,b#a ,c#a a#a;b#a;c#a _/ lambda 7a lambda7,p phi ,ux ----------------- ,ux ---------------------------------------- --1 7#a7 ,b#j ,c#j - ,b#a - ,c#a abc _/lambda#a abcdlambda #a - ------ - ---------------- a#a;b#a;c#a _/#j 7a lambda7,p and any confocal ellipsoid defined by lambda1 internal or external to lambda lambda#a1 may be supposed to swim with the liquid for an instant1 without distortion or rotation1 with velocity along ,ox ,blambda ,clambda - ,b#a - ,c#a ,u ---------------------------------- ,b#j ,c#j - ,b#a - ,c#a ,since - ,ux is the velocity function for the liquid ,w filling the ellipsoid lambda #j1 and moving bodily with it1 the effective inertia of the liquid in the interspace is ,a#j ,b#a ,c#a ----------------- ,w4 7#b7 ,b#j ,c#j - ,b#a - ,c#a ,if the ellipsoid is of revolution1 with b c1 ,a #b;,b#a phi ,ux -------1 7#c7 ,b#j - ,b#a and the ,stokes' current function psi can be written down ,b - ,b#a psi - ,uy -------2 7#d7 ,b#j - ,b#a reducing1 when the liquid extends to infinity and ,b#a #j1 to ,a ,b phi ,ux --1 psi - ,uy --2 7#e7 ,b#j ,b#j so that in the relative motion past the body1 as when fixed in the current ,u parallel to x,o1 _/ ,a _/ ,b phi ,ux 7 #a -- 71 psi ,uy 7 #a - -- 74 7#f7 ,b#j _/ ,b#j _/ ,changing the origin from the centre to the focus of a prolate spheroid1 then putting b pa1 lambda lambdaa1 and proceeding to the limit where a oo1 we find for a paraboloid of revolution p ,b p ,b -------------1 -- -------------1 7#g7 p lambda ,b#j p lambda y ------------- p lambda - #bx1 7#h7 p lambda with lambda #j over the surface of the paraboloid2 and then psi ,u y - proot7x y7 px2 7#i7 psi -,up root7x y7 - x2 7#aj7 phi -,up log root7x y7 x4 7#aa7 ,the relative path of a liquid particle is along a stream line psi ,uc1 a constant1 7#ab7 py - 7y - c7 py - 7y - c7 x -----------------1 root7x y7 ----------------- 7#ac7 #bp7y - c7 #bp7y - c7 a ,c#d2 while the absolute path of a particle in space will be given by dy r - x y - c -- - ----- -------1 7#ad7 dx y #bpy y - c ae7-x_/p74 7#ae7 #df4 ,between two concentric spheres1 with a lambda r1 a lambda#a a#a1 7#a7 ,a ,b ,c a_/#cr1 a a a a -- #b --- -- #b --- r a#a r a#a phi ,ux -----------1 psi ,uy ----------2 7#b7 #a - a#d_/;a#a #a - a_/a#a and the effective inertia of the liquid in the interspace is ,a#j #b;,a#a a#a #b;a --------- ,w --------- ,w4 7#c7 #b;,a#j - #b;,a#a a#a - a ,when the spheres are not concentric1 an expression for the effective inertia can be found by the method of images 7,w4 ,m4 ,hicks1 ,phil4 ,trans41 #ahhj74 ,the image of a source of strength mu at ,s outside a sphere of radius a is a source of strength mua_/f at ,h1 where ,,os f1 ,,oh a_/f1 and a line sink reaching from the image ,h to the centre ,o of line strength - mu_/a2 this combination will be found to produce no flow across the surface of the sphere4 ,taking ,ox along ,,os1 the ,stokes' function at ,p for the source ,s is mu cos ,p,sx1 and of the source ,h and line sink ,,oh is mu7a_/f7 cos ,p,hx and -7mu_/a77,,po - ,,ph72 so that _/ a ,,po - ,,ph psi mu 7cos ,p,sx --- cos ,p,hx - ------- 71 7#d7 f a _/ and psi -mu1 a constant1 over the surface of the sphere1 so that there is no flow across4 ,when the source ,s is inside the sphere and ,h outside1 the line sink must extend from ,h to infinity in the image system2 to realize physically the condition of zero flow across the sphere1 an equal sink must be introduced at some other internal point ,s4 ,when ,s and ,s lie on the same radius1 taken along ,ox1 the ,stokes' function can be written down2 and when ,s and ,s coalesce a doublet is produced1 with a doublet image at ,h4 ,for a doublet at ,s1 of moment m1 the ,stokes' function is d y m-- cos ,p,sx -m---2 7#e7 df ,,ps and for its image at ,h the ,stokes' function is d a y m-- cos ,p,hx -m-- ---2 7#f7 df f ,,ph so that for the combination _/a #a #a y _/ a f psi my 7 -- --- - --- 7 m-- 7 --- - --- 71 7#g7 f ,,ph ,,ps_/ f ,,ph ,,ps_/ and this vanishes over the surface of the sphere4 ,there is ao ,stokes' function when the axis of the doublet at ,s does not pass through ,o2 the image system will consist of an inclined doublet at ,h1 making an equal angle with ,,os as the doublet ,s1 and of a parallel negative line doublet1 extending from ,h to ,o1 of moment varying as the distance from ,o4 ,a distribution of sources and doublets over a moving surface will enable an expression to be obtained for the velocity function of a body moving in the presence of a fixed sphere1 or inside it4 ,the method of electrical images will enable the stream function psi to be inferred from a distribution of doublets1 finite in number when the surface is composed of two spheres intersecting at an angle pi_/m1 where m is an integer 7,r4 ,a4 ,herman1 ,quart4 ,jour4 of ,math4 xxii474 ,thus for m #b1 the spheres are orthogonal1 and it can be verified that _/ a#a a#b a psi ,uy 7 #a - --- - --- -- 71 7#h7 r#a r#b r _/ where a#a1 a#b1 a a#a;a#b_/root7a#a a#b7 is the radius of the spheres and their circle of intersection1 and r#a1 r#b1 r the distances of a point from their centres4 ,the corresponding expression for two orthogonal cylinders will be _/ a#a a#b a psi ,uy 7 #a - --- - --- -- 74 7#i7 r#a r#b r _/ ,with a#b oo1 these reduce to _/ a#e x _/ a#d x psi ,uy 7 #a - --- 7 ---1 or ,uy 7 #a - --- 7 ---1 7#aj7 r#e _/ a r#d _/ a for a sphere or cylinder1 and a diametral plane4 ,two equal spheres1 intersecting at #abj1 will require x a a#d7;a - #bx7 a a#d7;a #bx7 psi ,uy --- - ---- ----------- ---- - ----------- 1 7#aa7 a #br#a #br#ae #br#b #br#be with a similar expression for cylinders2 so that the plane x #j may be introduced as a boundary1 cutting the surface at #fj4 ,the motion of these cylinders across the line of centres is the equivalent of a line doublet along each axis4 #dg4 ,the extension of ,green's solution to a rotation of the ellipsoid was made by ,a4 ,clebsch1 by taking a velocity function phi xychi 7#a7 for a rotation ,r about ,oz2 and a similar procedure shows that an ellipsoidal surface lambda may be in rotation about ,oz without disturbing the motion if _/ #a #a dx 7 ------------ ------------ 7 chi #b--------- a lambda b lambda _/ dlambda ,r - ---------------------------------------- -------------1 7#b7 #a_/7;b lambda - #a_/7;a lambda7 and that the continuity of the liquid is secured if dchi 7a lambda7#c_/b 7b lambda7#c_/b 7c lambda7 --------- constant1 7#c7 dlambda _/ oo ,ndlambda ,n ,blambda - ,alambda chi ------------------------------- --- 4 -----------------------2 7#d7 _/lambda 7a lambda77b lambda7,p abc a - b and at the surface lambda #j1 _/ #a #a ,n ,b#j - ,a#j ,n #a 7 -- -- 7 --- ------- - --- ---- a b_/ abc a - b abc ab ,r - ----------------------------------1 7#e7 #a_/;b - #a_/;a ,n #a_/;b - #a_/;a --- ,r --------------------------1 7#f7 abc #a _/ #a #a ,b#j - ,a#j ---- - 7 -- -- 7 ------- ab a b_/ a - b 7a - b7_/7a b7 ,r -------------------------------4 7a - b7_/7a b7 - 7,b#j - ,a#j7 ,the velocity function of the liquid inside the ellipsoid lambda #j due to the same angular velocity will be phi#a ,rxy7a - b7_/7a b71 7#g7 and on the surface outside ,n ,b#j - ,a#j phi#j xychi#j xy--- -------1 7#h7 abc a - b so that the ratio of the exterior and interior value of phi at the surface is phi#j ,b#j - ,a#j ------ -------------------------------1 7#i7 phi#a 7a - b7_/7a b7 - 7,b#j - ,a#j7 and this is the ratio of the effective angular inertia of the liquid1 outside and inside the ellipsoid lambda #j4 ,the extension to the case where the liquid is bounded externally by a fixed ellipsoid lambda lambda#a is made in a similar manner1 by putting phi xy7chi ,m71 7#aj7 and the ratio of the effective angular inertia in 7#i7 is changed to a#a - b#a abc 7,b#j - ,a#j7 - 7,b#a - ,a#a7 --------- ------ a#a b#a a#a;b#a;c#a ---------------------------------------- ----------4 7#aa7 a - b a#a - b#a abc ------- - --------- ------ - 7,b#j - ,a#j7 7,b#a - ,a#a7 a b a#a b#a a#a;b#a;c#a ,make c oo for confocal elliptic cylinders2 and then _/oo ab ab _/ _/b lambda ,alambda ---------------------------------------- ------------- ------- 7 #a - _/ ------------- 71 7#ab7 _/lambda 7a lambda7root7#d;a lambdab lambda7 a - b _/ a lambda _/ ab _/ _/a lambda ,blambda ------- 7 _/ ------------- - #a 71 ,clambda #j2 a - b _/ b lambda _/ and then as above in #ca1 with a c ch alpha1 b c sh alpha1 a#a root7a lambda7 c ch alpha#a1 b#a c sh alpha#a 7#ac7 the ratio in 7#aa7 agrees with #ca 7#f74 ,as before in #ca1 the rotation may be resolved into a shear-pair1 in planes perpendicular to ,ox and ,oy4 ,a torsion of the ellipsoidal surface will give rise to a velocity function of the form phi xyz,omega1 where ,omega can be expressed by the elliptic integrals ,alambda1 ,blambda1 ,clambda1 in a similar manner1 since _/ oo ,omega ,l dlambda_/,p _/ lambda #dh4 ,the determination of the phi's and chi's is a kinematical problem1 solved as yet only for a few cases1 such as those discussed above4 ,but supposing them determined for the motion of a body through a liquid1 the kinetic energy ,t of the system1 liquid and body1 is expressible as a quadratic function of the components ,u1 ,v1 ,w1 ,p1 ,q1 ,r4 ,the partial differential coefficient of ,t with respect to a component of velocity1 linear or angular1 will be the component of momentum1 linear or angular1 which corresponds4 ,conversely1 if the kinetic energy ,t is expressed as a quadratic function of x#a1 x#b1 x#c1 y#a1 y#b1 y#c1 the components of momentum1 the partial differential coefficient with respect to a momentum component will give the component of velocity to correspond4 ,these theorems1 which hold for the motion of a single rigid body1 are true generally for a flexible system1 such as considered here for a liquid1 with one or more rigid bodies swimming in it2 and they express the statement that the work done by an impulse is the product of the impulse and the arithmetic mean of the initial and final velocity2 so that the kinetic energy is the work done by the impulse in starting the motion from rest4 ,thus if ,t is expressed as a quadratic function of ,u1 ,v1 ,w1 ,p1 ,q1 ,r1 the components of momentum corresponding are d,t d,t d,t x#a --1 x#b --1 x#c --1 7#a7 d,u d,v d,w d,t d,t d,t y#a --1 y#b --1 y#c --2 d,p d,q d,r but when it is expressed as a quadratic function of x#a1 x#b1 x#c1 y#a1 y#b1 y#c1 d,t d,t d,t ,u ---1 ,v ---1 ,w ---1 7#b7 dx#a dx#b dx#c d,t d,t d,t ,p ---1 ,q ---1 ,r ---4 dy#a dy#b dy#c ,the second system of expression was chosen by ,clebsch and adopted by ,halphen in his ,fonctions elliptiques2 and thence the dynamical equations follow dx#a d,t d,t ,x --- - x#b--- x#c---1 ,y 4441 ,z 4441 7#c7 dt dy#c dy#b dy#a d,t d,t d,t d,t ,l --- - y#b--- y#c--- - x#b--- x#b---1 ,m 4441 ,n 4441 7#d7 dt dy#c dy#b dx#c dx#b where ,x1 ,y1 ,z1 ,l1 ,m1 ,n denote components of external applied force on the body4 ,these equations are proved by taking a line fixed in space1 whose direction cosines are l1 m1 n1 then dl dm dn -- m,r - n,q1 -- n,p - l,r1 -- l,q - m,p4 7#e7 dt dt dt ,if ,p denotes the resultant linear impulse or momentum in this direction ,p lx#a mx#b nx#c1 7#f7 d,p dl dm dn -- --x#a --x#b --x#c dt dt dt dt dx#a dx#b dx#c l--- m--- n---1 dt dt dt _/ dx#a l 7 --- - x#b,r x#c,q 7 dt _/ _/ dx#b m 7 --- - x#c,p x#a,r 7 dt _/ _/ dx#c n 7 --- - x#a,q x#b,p 7 dt _/ l,x m,y n,z1 7#g7 for all values of l1 m1 n4 ,next1 taking a fixed origin ,omega and axes parallel to ,ox1 ,oy1 ,oz through ,o1 and denoting by x1 y1 z the coordinates of ,o1 and by ,g the component angular momentum about ,omega in the direction 7l1 m1 n7 ,g l7y#a - x#bz x#cy7 m7y#b - x#cx x#az7 n7y#c - x#ay x#bx74 7#h7 ,differentiating with respect to t1 and afterwards moving the fixed origin up to the moving origin ,o1 so that dx dy dz x y z #j1 but -- ,u1 -- ,v1 -- ,w1 dt dt dt d,g _/ dy#a -- l 7 --- - y#b,r y#c,q - x#b,w x#c,v 7 dt dt _/ _/ dy#b m 7 --- - y#c,p y#a,r - x#c,u x#a,w 7 dt _/ _/ dy#c n 7 --- - y#a,q y#b,p - x#a,v x#b,u 7 dt _/ l,l m,m n,n1 7#i7 for all values of l1 m1 n4 ,when no external force acts1 the case which we shall consider1 there are three integrals of the equations of motion 7i47 ,t constant1 7ii47 x#a x#b x#c ,f1 a constant1 7iii47 x#ay#a x#by#b x#cy#c n ,,gf1 a constant2 and the dynamical equations in 7#c7 express the fact that x#a1 x#b1 x#c are the components of a constant vector having a fixed direction2 while 7#d7 shows that the vector resultant of y#a1 y#b1 y#c moves as if subject to a couple of components x#b,w - x#c,v1 x#c,u - x#a,w1 x#a,v - x#b,u1 7#aj7 and the resultant couple is therefore perpendicular to ,f1 the resultant of x#a1 x#b1 x#c1 so that the component along ,,of is constant1 as expressed by 7iii74 ,if a fourth integral is obtainable1 the solution is reducible to a quadrature1 but this is not possible except in a limited series of cases1 investigated by ,h4 ,weber1 ,f4 ,ktter1 ,r4 ,liouville1 ,caspary1 ,jukovsky1 ,liapounoff1 ,kolosoff and others1 chiefly ,russian mathematicians2 and the general solution requires the double-theta hyperelliptic function4 #di4 ,in the motion which can be solved by the elliptic function1 the most general expression of the kinetic energy was shown by ,a4 ,clebsch to take the form ,t p7x#a x#b7 px#c q7x#ay#a x#by#b7 qx#cy#c r7y#a y#b7 ry#c 7#a7 so that a fourth integral is given by dy#c_/;dt #j1 y#c constant2 7#b7 dx#c --- x#a7qx#b ry#b7 - x#b7qx#a ry#a7 r7x#ay#b - x#by#a71 7#c7 dt #a _/ dx#c -- 7 --- 7 7x#a x#b77y#a y#b7 - 7x#ay#a x#by#b7 r dt _/ 7x#a x#b77y#a y#b7 - 7,,fg - x#cy#c7 7x#a x#b77y#a y#b y#c - ,g7 - 7,gx#c - ,fy#c71 7#d7 in which x#a x#b ,f - x#c1 x#ay#a x#by#b ,,fg - x#cy#c1 7#e7 r7y#a y#b7 #b,t - p7x#a x#b7 - px#c - #bq7x#ay#a x#by#b7 - #bqx#cy#c - ry#c 7p - p7x#c #b7q - q7x#cy#c m#a1 7#f7 m#a - #b,t - p,f - #bq,f,g - r#ay#c 7#g7 so that #a _/ dx#c -- 7 --- 7 ,x#c 7#h7 r dt _/ where ,x#c is a quartic function of x#c1 and thus t is given by an elliptic integral of the first kind2 and by inversion x#c is in elliptic function of the time t4 ,now 7x#a - x#b;i77y#a y#b;i7 x#ay#a x#by#b i7x#ay#b - x#by#a7 ,,fg - xy#cy#c i,v-,x#c1 7#i7 y#a y#b;i ,,fg - x#cy#c iroot,x#c -------- --------------------- 1 7#aj7 x#a x#b;i x#a x#b d -- 7x#a x#b;i7 -i7q - q7x#c ry#c irx#c7y#a y#b;i71 7#aa7 dt d ,,fg - x#cy#c iroot,x#c --- log 7x#a x#b;i7 dti -7q - q7x - ry rx ---------------------1 7#ab7 dti ,f - x#c d _/x#a x#b;i ,fy#c - ,gx#c --- log _/ -------- -7q - q7x#c - 7r - r7y#c - ,fr---------1 7#ac7 dti _/ x#a - x#b;i ,f - x#c requiring the elliptic integral of the third kind2 thence the expression of x#a x#b;i and y#a y#b;i4 ,introducing ,euler's angles theta1 phi1 psi1 x#a ,f sin theta sin phi1 x#b ,f sin theta cos phi1 x#a x#b;i i,f sin thetaepsilon7-psii71 x#c ,f cos theta2 7#ad7 dpsi sin theta ------ ,p sin phi ,q cosphi1 7#ae7 dt dpsi d,t d,t ,f sintheta ------ --- x#a --- x#b dt dy#a dy#b 7qx#a ry#a7x#a 7qx#b ry#b7x#b qx#a x#b7 r 7x#ay#a x#by#b7 g,f sin theta r7,,fg - x#cy#c71 7#af7 _/ ,,fg - x#cy#c ,fr dx#c psi - q,ft --------- --------1 7#ag7 _/ ,f - x#c root,x#c elliptic integrals of the third kind4 ,employing ,g4 ,kirchhoff's expressions for ,x1 ,y1 ,z1 the coordinates of the centre of the body1 ,,fx y#a cos x,y y#b cos y,y y#c cos z,y1 7#ah7 ,,fy -y#a cos x,x y#b cos y,x y#c cos z,x1 7#ai7 ,g y#a cos x,z y#b cos y,z y#c cos z,z1 7#bj7 ,f7,x ,y7 y#a y#b y#c - ,g1 7#ba7 ,fy#c - ,gx#c iroot,x#c ,f7,x ,yi7 --------------------- epsilonpsii4 7#bb7 root7,f - x#c7 ,suppose x#c - ,f is a repeated factor of ,x#c1 then y#c ,g1 and p - p q - q ,x#c 7x#c - ,f7 ------7x#c ,f7 #b------;,g7x#c ,f7 - ,g 1 7#bc7 r r and putting x#c - ,f y1 _/ dy p - p q - q 7 -- 7 ry #d ------ ,f #d ------ ,,fg - ,g dt _/ r r _/ p - p q - q p - p #b 7 #b ------ ,f ------ ,g 7 y ------ y 1 7#bd7 r r _/ r so that the stability of this axial movement is secured if p - p q - q ,a #d ------,f #d ------,,fg - ,g 7#be7 r r is negative1 and then the axis makes r,v-7-,a7_/pi nutations per second4 ,otherwise1 if ,a is positive _/ dy rt ---------------------- _/ yroot7,a #b;,by ,cy7 #a sh7-#a7 root,aroot7,a #b;,by ,cy7 #a ch7-#a7 ,a ,by ------- ---------------------------- ------- ---------------1 7#bf7 root,a ch7-#a7 yroot7,b ,,ac7 root,a sh7-#a7 yroot7,b ,,ac7 and the axis falls away ultimately from its original direction4 ,a number of cases are worked out in the ,american ,journal of ,mathematics 7#aijg71 in which the motion is made algebraical by the use of the pseudo-elliptic integral4 ,to give a simple instance1 changing to the stereographic projection by putting tan theta x1 7,nxepsii7#c_/b 7x #a7root,x#a i7x - #a7root,x#b1 7#bg7 ,x#a -- ax#d #b;ax #c7;a b7x #b;bx b1 7#bh7 ,x#b ,n -#h7;a b71 7#bi7 will give a possible state of motion of the axis of the body2 and the motion of the centre may then be inferred from 7#bb74 #ej4 ,the theory preceding is of practical application in the investigation of the stability of the axial motion of a submarine boat1 of the elongated gas bag of an airship1 or of a spinning rifled projectile4 ,in the steady motion under no force of such a body in a medium1 the centre of gravity describes a helix1 while the axis describes a cone round the direction of motion of the centre of gravity1 and the couple causing precession is due to the displacement of the medium4 ,in the absence of a medium the inertia of the body to translation is the same in all directions1 and is measured by the weight ,w1 and under no force the ,c4,g4 proceeds in a straight line1 and the axis of rotation through the ,c4,g4 preserves its original direction1 if a principal axis of the body2 otherwise the axis describes a cone1 right circular if the body has uniaxial symmetry1 and a ,poinsot cone in the general case4 ,but the presence of the medium makes the effective inertia depend on the direction of motion with respect to the external shape of the body1 and on ,w the weight of fluid medium displaced4 ,consider1 for example1 a submarine boat under water2 the inertia is different for axial and broadside motion1 and may be represented by c#a ,w ,walpha1 c#b ,w ,wbeta1 7#a7 where alpha1 beta are numerical factors depending on the external shape2 and if the ,c4,g4 is moving with velocity ,v at an angle phi with the axis1 so that the axial and broadside component of velocity is u ,v cos phi1 v ,v sin phi1 the total momentum ,f of the medium1 represented by the vector ,,of at an angle theta with the axis1 will have components1 expressed in sec4 lb41 u ,v v ,v ,f cos theta c#a --- 7,w ,walpha7 --- cos phi1 ,f sin theta c#b --- 7,w ,wbeta7 --- sin phi4 7#b7 g g g g ,suppose the body is kept from turning as it advances2 after t seconds the ,c4,g4 will have moved from ,o to ,o1 where ,,oo ,vt2 and at ,o the momentum is the same in magnitude as before1 but its vector is displaced from ,,of to ,o,f4 ,for the body alone the resultant of the components of momentum ,v ,v ,v ,w --- cos phi and ,w --- sin phi is ,w --- sec4 lb41 7#c7 g g g acting along ,,oo1 and so is unaltered4 ,but the change of the resultant momentum ,f of the medium as well as of the body from the vector ,,of to ,o,f requires an impulse couple1 tending to increase the angle ,,foo1 of magnitude1 in sec4 foot-pounds ,f,,oosin ,,foo ,f,vt sin 7theta - phi71 7#d7 equivalent to an incessant couple ,n ,,fv sin 7theta - phi7 7,f sin theta cos phi - ,f cos theta sin phi7,v 7c#b - c#a77,v_/g7 sin phi cos phi ,w7beta - alphauv_/g74 7#e7 ,this ,n is the couple in foot-pounds changing the momentum of the medium1 the momentum of the body alone remaining the same2 the medium reacts on the body with the same couple ,n in the opposite direction1 tending when c#b-;c#a is positive to set the body broadside to the advance4 ,an oblate flattened body1 like a disk or plate1 has c#b - c#a negative1 so that the medium steers the body axially2 this may be verified by a plate dropped in water1 and a leaf or disk or rocket-stick or piece of paper falling in air4 ,a card will show the influence of the couple ,n if projected with a spin in its plane1 when it will be found to change its aspect in the air4 ,an elongated body like a ship has c#b-;c#a positive1 and the couple ,n tends to disturb the axial movement and makes it unstable1 so that a steamer requires to be steered by constant attention at the helm4 ,consider a submarine boat or airship moving freely with the direction of the resultant momentum horizontal1 and the axis at a slight inclination theta4 ,with no reserve of buoyancy ,w ,w1 and the couple ,n1 tending to increase theta1 has the effect of diminishing the metacentric height by h ft4 vertical1 where c#a u ,wh tantheta ,n 7c#b - c#a7 -- --- tan theta1 7#f7 c#b g c#b - c#a c#a u #a alpha u h ------- -- --- 7beta - alpha ----------- ---4 7#g7 ,w c#b g #a beta g #ea4 ,an elongated shot is made to preserve its axial flight through the air by giving it the spin sufficient for stability1 without which it would turn broadside to its advance2 a top in the same way is made to stand upright on the point in the position of equilibrium1 unstable statically but dynamically stable if the spin is sufficient2 and the investigation proceeds in the same way for the two problems 7see ,,gyroscope74 ,the effective angular inertia of the body in the medium is now required2 denote it by ,c#a about the axis of the figure1 and by ,c#b about a diameter of the mean section4 ,a rotation about the axis of a figure of revolution does not set the medium in motion1 so that ,c#a is the moment of inertia of the body about the axis1 denoted by ,wk#a4 ,but if ,wk#b is the moment of inertia of the body about a mean diameter1 and omega the angular velocity about it generated by an impulse couple ,m1 and ,m is the couple required to set the surrounding medium in motion1 supposed of effective radius of gyration k1 ,wk#bomega ,m - ,m1 ,wkomega ,m1 7#a7 ,wk#b ,wkomega ,m1 7#b7 ,c#b ,wk#b ,wk 7,w ,wepsilon7k#b1 7#c7 in which we have put k epsilonk1 where epsilon is a numerical factor depending on the shape4 ,if the shot is spinning about its axis with angular velocity p1 and is preceding steadily at a rate mu about a line parallel to the resultant momentum ,f at an angle theta1 the velocity of the vector of angular momentum1 as in the case of a top1 is ,c#apmu sin theta - ,c#bmu sin theta cos theta2 7#d7 and equating this to the impressed couple 7multiplied by g71 that is1 to c#a g,n 7c#a - c#b7-- u tan theta1 7#e7 c#b and dividing out sintheta1 which equated to zero would imply perfect centring1 we obtain c#a ,c#bmu cos theta - ,c#apmu 7c#b - c#a7-- u sec theta #j4 7#f7 c#b ,the least admissible value of p is that which makes the roots equal of this quadratic in mu1 and then ,c#a mu --p sec theta1 7#g7 ,c#b the roots would be imaginary for a value of p smaller than given by c#a ,c#ap - #d7;c#b - c#a7-- ,c#bu #j1 7#h7 c#b p c#a ,c#b -- #d 7c#b - c#a7 -- ---4 7#i7 u c#b ,c#a ,table of ,rifling for ,stability of an ,elongated ,projectile1 x ,calibres long1 giving delta the ,angle of ,rifling1 and n the ,pitch of ,rifling in ,calibres4 ---------------------------------------- ---------------------------------------- ----------- ,cast-iron ,common ,palliser ,shell ,solid ,steel ,solid ,lead ,shell f #b_/c1 f 1 ,s4,g4 #h4 ,bullet ,bullet f #j1 ,s4,g4 #g4b4 f #j1 ,s4,g4 #h4 ,s4,g4 #aj4i4 ---------------------------------------- ---------------------------------------- ------ x beta-alphadelta n delta n delta n delta n ---------------------------------------- ---------------------------------------- ------ #a4j #j4jjjj #j #j;,infinity #j #j;,infinity #j #j;,infinity #j #j;,infinity #b4j #j4didb #b #di #fc4hg #b #cb #ga4jh #b #bi #gb4ba #b #jh #hd4bi #b4e #j4fjef #c #df #dg4ia #c #bc #ec4cb #c #ai #ed4ag #b #ea #fc4bd #c4j #j4fhai #d #da #ch4de #d #ac #db4gi #d #ji #dc4dg #c #ch #ej4gd #c4e #j4gcgj #e #ce #cb4ac #e #jb #ce4ge #d #eh #cf4cc #d #ae #db4dj #d4j #j4gghb #f #cj #bg4fj #e #ea #cj4gb #e #de #ca4ba #d #ef #cf4dc #d4e #j4hajj #g #bd #bd4bj #f #dj #bf4ic #f #cb #bg4cf #e #cg #ca4id #e4j #j4hcea #h #af #ba4ef #g #bh #bc4ih #g #ba #bd4cf #f #ah #bh4dd #f4j #j4hgba #aj #je #ag4fg #i #jd #ai4fg #h #ef #ai4ih #g #dj #bc4cc #aj4j #j4icie #af #eg #aj4ca #ae #ai #aa4dg #ae #je #aa4fe #ac #jj #ac4fj ,infinity #a4jjjj #ij #jj #j4jj #ij #jj #j4jj #ij #jj #j4jj #ij #jj #j4jj ---------------------------------------- ---------------------------------------- ------ ,if the shot is moving as if fired from a gun of calibre d inches1 in which the rifling makes one turn in a pitch of n calibres or nd inches1 so that the angle delta of the rifling is given by tan delta pid_/nd dp_/u1 7#aj7 which is the ratio of the linear velocity of rotation dp to u1 the velocity of advance1 c#a ,c#b;d tan delta pi_/n dp_/#du 7c#b - c#a7 -- ---- c#b ,c#a ,w _/ ,w _/ k#b #a --- alpha 7 #a ---epsilon 7 7 -- 7 ,w ,w ,w _/ d _/ --- 7beta - alpha7 --------------- -----------------------------4 7#aa7 ,w ,w _/ k#a #d #a ---beta 7 -- 7 ,w d _/ ,for a shot in air the ratio ,w_/,w is so small that the square may be neglected1 and formula 7#aa7 can be replaced for practical purpose in artillery by pi ,w _/ k#b _/ _/ k#a #d tandelta ----- --- 7beta - alpha7 7 -- 7 _/ 7 -- 71 7#ab7 n ,w d _/ _/ d _/ if then we can calculate beta1 alpha1 or beta - alpha for the external shape of the shot1 this equation will give the value of delta and n required for stability of flight in the air4 ,the ellipsoid is the only shape for which alpha and beta have so far been determined analytically1 as shown already in #dd1 so we must restrict our calculation to an egg-shaped bullet1 bounded by a prolate ellipsoid of revolution1 in which1 with b c1 _/ oo ab dlambda _/ oo ab dlambda ,a#j ---------------------------------------- --------------- -----------------------------------1 7#ac7 _/ #j 7a lambda7root#d7;a lambda77b lambda7 _/ #j #b7;a lambda7#c_/b 7b lambda7 ,a#j #b;,b#j #a1 7#ad7 ,a#j ,b#j #a - ,a#j #a alpha ------1 beta ------ ------ ------------4 7#ae7 #a - ,a#j #a - ,b#j #a ,a#j #a #b;alpha ,the length of the shot being denoted by l and the calibre by d1 and the length in calibres by x l_/d #b;a_/#b;b x1 7#af7 x #a ,a#j ----------- ch7-#a7x - ------1 7#ag7 7x- #a7c_/b x - #a -x x #b;,b#j ----------- ch7-#a7x ------1 7#ah7 x - #a7c_/b x #a x sh7-#a7 root7x-#a7 x x,a#j #b;,b#j ---------------------- ------------ log x root7x - #a74 7#ai7 root7x-#a7 root7x-#a7 ,if sigma denotes the density of the metal1 and if the shell has a cavity homothetic with the external ellipsoidal shape1 a fraction f of the linear scale2 then the volume of a round shot being #a_/f pi d#c1 and #a_/f pi d#c x of a shot x calibres long ,w #a_/f pi d#c x 7i - f#c7 sigma1 7#bj7 d ,wk#a #a_/f pi d#c x -- 7#a - f#e7 sigma1 7#ba7 #aj l d ,wk#b #a_/f pi d#c x ------- 7#a - f#e7 sigma4 7#bb7 #bj ,if rho denotes the density of the air or medium ,w #a_/f pi d#c x rho1 7#bc7 ,w #a rho --- ------ -------1 7#bd7 ,w #a - f sigma k#a #a #a - f#e k#b x #a --- --- -------1 ---- ------1 7#be7 d #aj #a - f k#a #b rho x #a tan delta ------- 7beta - alpha7-------------1 7#bf7 sigma #a_/e 7#a - f#e7 in which sigma_/rho may be replaced by #hjj times the ,s4,g4 of the metal1 taking water as #hjj times denser than air on the average1 in round numbers1 and formula 7#aj7 may be written n tan delta pi1 or ndelta #ahj1 when delta is a small angle1 and given in degrees4 ,from this formula 7#bf7 the table following has been calculated by ,a4 ,g4 ,hadcock1 and the results are in agreement with practical experience4 #eb4 ,in the steady motion the centre of the shot describes a helix1 with axial velocity _/ c#a u cos theta v sin theta 7 l -- tan theta 7 u cos theta asympt u sec theta1 7#a7 c#b _/ and transverse velocity _/ c#a u sin theta - v cos theta 7 l - -- 7 u sin theta asympt 7beta - alpha7 u sin theta2 7#b7 c#b _/ and the time of completing a turn of the spiral is #bpi_/mu4 ,when mu has the critical value in 7#g71 #bpi #dpi ,c#b #bpi ----- ----- -- cos theta ----- 7x #a7 cos theta1 7#c7 mu p ,c#a p which makes the circumference of the cylinder on which the helix is wrapped #bpi #bpiu -----7u sin theta - v cos theta ------ 7beta - alpha7 7x #a7 sin theta cos theta mu p nd 7beta - alpha7 7x #a7 sin theta cos theta1 7#d7 and the length of one turn of the helix #bpi ----- 7u cos theta v sin theta 7 nd7x #a72 7#e7 mu thus for x #c1 the length is #aj times the pitch of the rifling4 #ec4 ,the ,motion of a ,perforated ,solid in ,liquid4--,in the preceding investigation1 the liquid stops dead when the body is brought to rest2 and when the body is in motion the surrounding liquid moves in a uniform manner with respect to axes fixed in the body1 and the force experienced by the body from the pressure of the liquid on its surface is the opposite of that required to change the motion of the liquid2 this has been expressed by the dynamical equations given above4 ,but if the body is perforated1 the liquid can circulate through a hole1 in reentrant stream lines linked with the body1 even while the body is at rest2 and no reaction from the surface can influence this circulation1 which may be supposed started in the ideal manner described in #bi1 by the application of impulsive pressure across an ideal membrane closing the hole1 by means of ideal mechanism connected with the body4 ,the body is held fixed1 and the reaction of the mechanism and the resultant of the impulsive pressure on the surface are a measure of the impulse1 linear xi1 eta1 zeta1 and angular lambda1 mu1 nu1 required to start the circulation4 ,this impulse will remain of constant magnitude1 and fixed relatively to the body1 which thus experiences an additional reaction from the circulation which is the opposite of the force required to change the position in space of the circulation impulse2 and these extra forces must be taken into account in the dynamical equations4 ,an article may be consulted in the ,phil4 ,mag41 ,april #ahic1 by ,g4 ,h4 ,bryan1 in which the analytical equations of motion are deduced of a perforated solid in liquid1 from considerations purely hydrodynamical4 ,the effect of an external circulation of vortex motion on the motion of a cylinder has been investigated in #bi2 a similar procedure will show the influence of circulation through a hole in a solid1 taking as the simplest illustration a ring-shaped figure1 with uniplanar motion1 and denoting by xi the resultant axial linear momentum of the circulation4 ,as the ring is moved from ,o to ,o in time t1 with velocity ,q1 and angular velocity ,r1 the components of liquid momentum change from alpha,m,u xi and beta,m,v along ,ox and ,oy to alpha,m,u xi and beta,m,v along ,ox and ,oy1 7#a7 the axis of the ring changing from ,ox to ,ox2 and ,u ,q cos theta1 ,v ,q sin theta1 ,u ,q cos 7theta - ,rt71 ,v ,q sin 7theta - ,rt71 7#b7 so that the increase of the components of momentum1 ,x#a1 ,y#a1 and ,n#a1 linear and angular1 are ,x#a 7alpha,m,u xi7cos ,rt - alpha,m,u - xi - beta,m,v sin ,rt 7alpha - beta7,m,q sin 7theta - ,rt7 sin ,rt - xi ver ,rt 7#c7 ,y#a 7alpha,m,u xi7 sin ,rt beta,m,v cos ,rt - beta,m,v 7alpha - beta7,m,q cos 7theta - ,rt7 sin ,rt xi sin ,,rt1 7#d7 ,n#a -7alpha,m,u xi7 sin 7theta - ,rt7 beta,m,v cos 7theta - ,rt7,,oo -7alpha - beta7,q cos 7theta - ,rt7 sin 7theta - ,rt7 - xi sin 7theta - ,rt7,qt4 7#e7 ,the components of force1 ,x1 ,y1 and ,n1 acting on the liquid at ,o1 and reacting on the body1 are then ,x lt4 ,x#a_/t 7alpha - beta7,m,,qr sin theta 7alpha - beta7,m,,vr1 7#f7 ,y lt4 ,y#a_/t 7alpha - beta7,m,,qr cos theta xi,r 7alpha - beta7,m,,ur xi,r1 7#g7 ,z lt4 ,z#a_/t -7alpha - beta7,m,q sin thetacostheta - xi,q sin theta -7alpha - beta7,m,u xi,v4 7#h7 ,now suppose the cylinder is free2 the additional forces acting on the body are the components of kinetic reaction of the liquid _/ d,u _/ d,v d,r -alpha,m 7 -- - ,,vr 71 -beta,m 7 -- ,,ur 71 epsilon,c--1 7#i7 dt _/ dt _/ dt so that its equations of motion are _/ d,u _/ d,u ,m 7 -- -,,vr 7 -alpha,m 7 -- - ,,vr 7 - 7alpha - beta7,m,,vr1 7#aj7 dt _/ dt _/ _/ d,v _/ d,v ,m 7 -- ,,ur 7 -beta,m 7 -- ,,ur 7 - 7alpha - beta7,m,,ur - xi,r1 7#aa7 dt _/ dt _/ d,r d,r ,c-- -epsilon,c-- 7alpha - beta7,m,,uv xi,v2 7#ab7 dt dt and putting as before ,m alpha,m c#a1 ,m beta,m c#b1 ,c epsilon,c ,c#c1 7#ac7 d,u c#a-- - c#b ,,vr #j1 7#ad7 dt d,v c#b-- 7c#a ,u xi7,r #j1 7#ae7 dt d,r c#c-- - 7c#a,u xi - c#b ,u7,v #j2 7#af7 dt showing the modification of the equations of plane motion1 due to the component xi of the circulation4 ,the integral of 7#ad7 and 7#ae7 may be written c#a,u xi ,f cos theta1 c#b,v - ,f sin theta1 7#ag7 dx ,f cos theta ,f sin theta xi -- ,u cos theta - ,v sin theta -------------- -------------- - ---- cos theta1 7#ah7 dt c#a c#b c#a dmu _/ ,f ,f xi ----- ,u sin theta ,v cos theta 7 -- - -- 7 sin theta cos theta - ---- sin theta1 7#ai7 dt c#a c#b _/ c#a dtheta _/ ,f ,f ,fxi dmu ,c#c--------- 7 -- - -- 7 sin theta cos theta - ----- sin theta ,f-----1 7#bj7 dt c#a c#b _/ c#a dt dtheta _/ ,f cos theta ,f sin theta ,fxi ,c#c-------- ,fy _/ - --------------- - --------------- #b----- cos theta ,h 2 7#ba7 dt _/ c#a c#b c#a so that cos theta and y is an elliptic function of the time4 ,when xi is absent1 dx_/dt is always positive1 and the centre of the body cannot describe loops2 but with xi1 the influence may be great enough to make dx_/dt change sign1 and so loops occur1 as shown in ,a4 ,b4 ,basset's ,hydrodynamics1 i4 #aib1 resembling the trochoidal curves1 which can be looped1 investigated in #bi for the motion of a cylinder under gravity1 when surrounded by a vortex4 ,the branch of hydrodynamics which discusses wave motion in a liquid or gas is given now in the articles ,,sound and ,,wave2 while the influence of viscosity is considered under ,,hydraulics4 ,,references4--,for the history and references to the original memoirs see ,report to the ,british ,association1 by ,g4 ,g4 ,stokes 7#ahdf71 and ,w4 ,m4 ,hicks 7#ahhb74 ,see also the ,fortschritte der ,mathematik1 and ,a4 ,e4 ,h4 ,love1 ,hydrodynamik in the ,encyklpadie der mathematischen ,wissenschaften 7#aija74 7,a4 ,g4 ,g47 ,,hydromedusae1 a group of marine animals1 recognized as belonging to the ,hydrozoa 7q4v47 by the following characters4 7#a7 ,the polyp 7hydropolyp7 is of simple structure1 typically much longer than broad1 without ectodermal oesophagus or mesenteries1 such as are seen in the anthopolyp 7see article ,,anthozoa72 the mouth is usually raised above the peristome on a short conical elevation or hypostome2 the ectoderm is without cilia4 7#b7 ,with very few exceptions1 the polyp is not the only type of individual that occurs1 but alternates in the life-cycle of a given species1 with a distinct type1 the medusa 7q4v471 while in other cases the polyp-stage may be absent altogether1 so that only medusa-individuals occur in the life-cycle4 ,the ,hydromedusae represent1 therefore1 a sub-class of the ,hydrozoa4 ,the only other sub-class is the ,scyphomedusae 7q4v474 ,the ,hydromedusae contrast with the ,scyphomedusae in the following points4 7#a7 ,the polyp1 when present1 is without the strongly developed longitudinal retractor muscles1 forming ridges 7taeniolae7 projecting into the digestive cavity1 seen in the scyphistoma or scyphopolyp4 7#b7 ,the medusa1 when present1 has a velum and is hence said to be craspedote2 the nervous system forms two continuous rings running above and below the velum2 the margin of the umbrella is not lobed 7except in ,narcomedusae7 but entire2 there are characteristic differences in the sense-organs 7see below1 and ,,scyphomedusae72 and gastral filaments 7phacellae71 subgenital pits1 c41 are absent4 7#c7 ,the gonads1 whether formed in the polyp or the medusa1 are developed in the ectoderm4 ,the ,hydromedusae form a widespread1 dominant and highly differentiated group of animals1 typically marine1 and found in all seas and in all zones of marine life4 ,fresh-water forms1 however1 are also known1 very few as regards species or genera1 but often extremely abundant as individuals4 ,in the ,british fresh-water fauna only two genera1 ,hydra and ,cordylophora1 are found2 in ,america occurs an additional genus1 ,microhydra4 ,the paucity of fresh-water forms contrasts sharply1 with the great abundance of marine genera common in all seas and on every shore4 ,the species of ,hydra1 however1 are extremely common and familiar inhabitants of ponds and ditches4 ,in fresh-water ,hydromedusae the life-cycle is usually secondarily simplified1 but in marine forms the life-cycle may be extremely complicated1 and a given species often passes in the course of its history through widely different forms adapted to different habitats and modes of life4 ,apart from larval or embryonic forms there are found typically two types of person1 as already stated1 the polyp and the medusa1 each of which may vary independently of the other1 since their environment and life-conditions are usually quite different4 ,hence both polyp and medusa present characters for classification1 and a given species1 genus or other taxonomic category may be defined by polyp-characters or medusa-characters or by both combined4 ,if our knowledge of the life-histories of these organisms were perfect1 their polymorphism would present no difficulties to classification2 but unfortunately this is far from being the case4 ,in the majority of cases we do not know the polyp corresponding to a given medusa1 or the medusa that arises from a given polyp4#a ,even when a medusa is seen to be budded1 from a polyp under observation in an aquarium1 the difficulty is not always solved1 since the freshly-liberated1 immature medusa may differ greatly from the full-grown1 sexually-mature medusa after several months of life on the high seas 7see figs4 #aa1 ,b1 ,c1 and #ei1 a1 b1 c74 ,to establish the exact relationship it is necessary not only to breed but to rear the medusa1 which cannot always be done in confinement4 ,the alternative is to fish all stages of the medusa in its growth in the open sea1 a slow and laborious method in which the chance of error is very great1 unless the series of stages is very complete4 ,at present1 therefore1 classifications of the ,hydromedusae have a more or less tentative character1 and are liable to revision with increased knowledge of the life-histories of these organisms4 ,many groups bear at present two names1 the one representing the group as defined by polyp-characters1 the other as defined by medusa-characters4 ,it is not even possible in all cases to be certain that the polyp-group corresponds exactly to the medusa-group1 especially in minor systematic categories1 such as families4 ,the following is the main outline of the classification that is ,adopted in the present article4 ,groups founded on polyp-characters are printed in ordinary type1 those founded on medusa-characters in italics4 ,for definitions of the groups see below4 ,sub-class ,hydromedusae 7,hydrozoa ,craspedota74 ,order ,i4 ,eleutheroblastea4 ,,ii4 ,hydroidea 7,leptolinae74 ,sub-order #a4 ,gymnoblastea 7,anthomedusae74 #b4 ,calyptoblastea 7,leptomedusae74 ,order ,,iii4 ,hydrocorallinae4 ,,iv4 ,graptolitoidea4 ,v4 ,trachylinae4 ,sub-order #a4 ,trachomedusae4 #b4 ,narcomedusae4 ,order ,,vi4 ,siphonophora4 ,sub-order #a4 ,chondrophorida4 #b4 ,calycophorida4 #c4 ,physophorida4 #d4 ,cystophorida4 ,organization and ,morphology of the ,hydromedusae4 ,as already stated1 there occur in the ,hydromedusae two distinct types of person1 the polyp and the medusa2 and either of them is capable of non-sexual reproduction by budding1 a process which may lead to the formation of colonies1 composed of more or fewer individuals combined and connected together4 ,the morphology of the group thus falls naturally into four sections--7#a7 the hydropolyp1 7#b7 the polyp-colony1 7#c7 the hydromedusa1 7#d7 the medusa-colonies4 ,since1 however1 medusa-colonies occur only in one group1 the ,siphonophora1 and divergent views are held with regard to the morphological interpretation of the members of a siphonophore1 only the first three of the above subdivisions of hydromedusa morphology will be dealt with here in a general way1 and the morphology of the ,siphonophora will be considered under the heading of the group itself4 ,illustration3 ,,fig4 #a4--;,diagram of a typical ,hydropolyp4 a1 ,hydranth2 b1 ,hydrocaulus2 c1 ,hydrorhiza2 t1 ,tentacle2 ps1 ,perisarc1 forming in the region of the hydranth a cup or hydrotheca 7h1 t71--which1 however1 is only found in polyps of the order ,calyptoblastea4 #a4 ,the ,hydropolyp 7fig4 #a7--,the general characters of this organism are described above and in the articles ,,hydrozoa and ,,polyp4 ,it is rarely free1 but usually fixed and incapable of locomotion4 ,the foot by which it is attached often sends out root-like processes--the hydrorhiza 7c74 ,the column 7b7 is generally long1 slender and stalk-like 7hydrocaulus74 ,just below the crown of tentacles1 however1 the body widens out to form a head1 termed1 the hydranth 7a71 containing a stomach-like dilatation of the digestive cavity4 ,on the upper face of the hydranth the crown of tentacles 7t7 surrounds the peristome1 from which rises the conical hypostome1 bearing the mouth at its extremity4 ,the general ectoderm covering the surface of the body has entirely lost the cilia present in the earlier larval stages 7planula71 and may be naked1 or clothed in a cuticle or exoskeleton1 the perisarc 7ps71 which in its simplest condition is a chitinous membrane secreted by the ectoderm4 ,the perisarc when present invests the hydrorhiza and hydrocaulus2 it may stop short below the hydranth1 or it may extend farther4 ,in general there are two types of exoskeleton1 characteristic of the two principal divisions of the ,hydroidea4 ,in the ,gymnoblastea the perisarc either stops below the hydranth1 or1 if continued on to it1 forms a closely-fitting investment extending as a thin cuticle as far as the bases of the tentacles 7e4g4 ,bimeria1 see ,g4 ,j4 ,allman #a1b pl4 xii4 figs1 #a and #c74 ,in the ,calyptoblastea the perisarc is always continued above the hydrocaulus1 and forms a cup1 the hydrangium or hydrotheca 7h1 t71 standing off from the body1 into which the hydranth can be retracted for shelter and protection4 ,illustration3 ,from ,allman's ,gymnoblastic ,hydroids1 by permission of the ,council of the ,ray ,society4 ,,fig4 #b4--,stauridium productum1 portion of the colony magnified2 p1 polyp2 rh1 hydrorhiza4 ,illustration3 ,,fig4 #c4--;,diagram of ,corymorpha4 ,a1 ,a hydriform person giving rise to medusiform persons by budding from the margin of the disk2 ,b1 free swimming medusa 7,steenstrupia of ,forbes7 detached from the same1 with manubrial genitalia1 7,anthomedusae7 and only one tentacle4 7,after ,allman74 ,the architecture of the hydropolyp1 simple though it be1 furnishes a long series of variations affecting each part of the body4 ,the greatest variation1 however1 is seen in the tentacles4 ,as regards number1 we find in the aberrant forms ,protohydra and ,microhydra tentacles entirely absent4 ,in the curious hydroid ,monobrachium a single tentacle is present1 and the same is the case in ,clathrozoon2 in ,amphibrachium and in ,lar 7fig4 #aa1 ,a7 the polyp bears two tentacles only4 ,the reduction of the tentacles in all these forms may be correlated with their mode of life1 and especially with living in a constant current of water1 which brings food-particles always from one direction and renders a complete whorl or circle of tentacles unnecessary4 ,thus ,microhydra lives amongst ,bryozoa1 and appears to utilize the currents produced by these animals4 ,protohydra occurs in oyster-banks and ,monobrachium also grows on the shells of bivalves1 and both these hydroids probably fish in the currents produced by the lamellibranchs4 ,amphibrachium grows in the tissues of a sponge1 ,euplectella1 and protrudes its hydranth into the canal-system of the sponge2 and ,lar grows on the tubes of the worm ,sabella4 ,with the exception of these forms1 reduced for the most part in correlation with a semi-parasitic mode of life1 the tentacles are usually numerous4 ,it is rare to find in the polyp a regular1 symmetrical disposition of the tentacles as in the medusa4 ,the primitive number of four in a whorl is seen1 however1 in ,stauridium 7fig4 #b7 and ,cladonema 7,allman #a1 pl4 xvii471 and in ,clavatella each whorl consists regularly of eight 7,allman1 loc4 cit4 pl4 xviii474 ,as a rule1 however1 the number in a whorl is irregular4 ,the tentacles may form a single whorl1 or more than one2 thus in ,corymorpha 7fig4 #c7 and ,tubularia 7fig4 #d7 there are two circlets2 in ,stauridium 7fig4 #b7 several2 in ,coryne and ,cordylophora the tentacles are scattered irregularly over the elongated hydranth4 ,as regards form1 the tentacles show a number of types1 of which the most important are 7#a7 filiform1 i4e4 cylindrical or tapering from base to extremity1 as in ,clava 7fig4 #e72 7#b7 capitate1 i4e4 knobbed at the extremity1 as in ,coryne 7see ,allman1 loc4 cit4 pl4 iv472 7#c7 branched1 a rare form in the polyp1 but seen in ,cladocoryne 7see ,allman1 loc4 cit4 p4 #chj1 fig4 #hb74 ,sometimes more than one type of form is found in the same polyp2 in ,pennaria and ,stauridium 7fig4 #b7 the upper whorls are capitate1 the lower filiform4 ,finally1 as regards structure1 the tentacles may retain their primitive hollow nature1 or become solid by obliteration of the axial cavity4 ,the hypostome of the hydropolyp may be small1 or1 on the other hand1 as in ,eudendrium 7,allman1 loc4 cit4 pls4 xiii41 xiv471 large and trumpet-shaped4 ,in the curious polyp ,myriothela the body of the polyp is differentiated into nutritive and reproductive portions4 ,illustration3 ,,fig4 #d4--;,diagram of ,tubularia indivisa4 ,a single hydriform person a bearing a stalk carrying numerous degenerate medusiform persons or sporosacs b4 7,after ,allman47 ,histology4--,the ectoderm of the hydropolyp is chiefly sensory1 contractile and protective in function4 ,it may also be glandular in places4 ,it consists of two regions1 an external epithelial layer and a more internal sub-epithelial layer4 ,the epithelial layer consists of 7#a7 so-called indifferent cells secreting the perisarc or cuticle and modified to form glandular cells in places2 for example1 the adhesive cells in the foot4 7#b7 ,sensory cells1 which may be fairly numerous in places1 especially on the tentacles1 but which occur always scattered and isolated1 never aggregated to form sense-organs as in the medusa4 7#c7 ,contractile or myo-epithelial cells1 with the cell prolonged at the base into a contractile muscle-fibre 7fig4 #f1 ,b74 ,in the hydropolyp the ectodermal muscle-fibres are always directed longitudinally4 ,belonging primarily to the epithelial layer1 the muscular cells may become secondarily sub-epithelial4 ,illustration3 ,from ,allman's ,gymnoblastic ,hydroids1 by permission of the ,council of the ,ray ,society4 ,,fig4 #e4--;,colonies of ,clava4 ,a1 ,clava squamata1 magnified4 ,b1 ,c4 multicornis1 natural size2 p1 polyp2 gon1 gonophores2 rh1 hydrorhiza4 ,the sub-epithelial layer consists primarily of the so-called interstitial cells1 lodged between the narrowed basal portions of the epithelial cells4 ,from them are developed two distinct types of histological elements2 the genital cells and the cnidoblasts or mother-cells of the nematocysts4 ,the sub-epithelial layer thus primarily constituted may be recruited by immigration from without of other elements1 more especially by nervous 7ganglion7 cells and muscle-cells derived from the epithelial layer4 ,in its fullest development1 therefore1 the sub-epithelial layer consists of four classes of cell-elements4 ,illustration3 ,,fig4 #f ,a4--,portion of the body-wall of ,hydra1 showing ectoderm cells above1 separated by structureless lamella from three flagellate endoderm cells below4 ,the latter are vacuolated1 and contain each a nucleus and several dark granules4 ,in the middle ectoderm cell are seen a nucleus and three nematocysts1 with trigger hairs projecting beyond the cuticle4 ,a large nematocyst1 with everted thread1 is seen in the right-hand ectodermal cell4 7,after ,f4 ,e4 ,schulze47 ,the genital cells are simple wandering cells 7archaeocytes71 at first minute and without any specially distinctive features1 until they begin to develop into germ-cells4 ,according to ,wulfert #fj the primitive germ-cells of ,gonothyraea can be distinguished soon after the fixation of the planula1 appearing amongst the interstitial cells of the ectoderm4 ,the germ-cells are capable of extensive migrations1 not only in the body of the same polyp1 but also from parent to bud through many non-sexual generations of polyps in a colony 7,a4 ,weismann #eh74 ,illustration3 ,,fig4 #f ,b4--,epidermo-muscular cells of ,hydra4 m1 muscular-fibre processes4 7,after ,kleinenberg1 from ,gegenbaur47 ,the cnidoblasts are the mother-cells of the nematocysts1 each cell producing one nematocyst in its interior4 ,the complete nematocyst 7fig4 #g7 is a spherical or oval capsule containing a hollow thread1 usually barbed1 coiled in its interior4 ,the capsule has a double wall1 an outer one 7o4c471 tough and rigid in nature1 and an inner one 7i4c47 of more flexible consistence4 ,the outer wall of the capsule is incomplete at one pole1 leaving an aperture through which the thread is discharged4 ,the inner membrane is continuous with the wall of the hollow thread at a spot immediately below the aperture in the outer wall1 so that the thread itself 7f7 is simply a hollow prolongation of the wall of the inner capsule inverted and pushed into its cavity4 ,the entire nematocyst is enclosed in the cnidoblast which formed it4 ,when the nematocyst is completely developed1 the cnidoblast passes outwards so as to occupy a superficial position in the ectoderm1 and a delicate protoplasmic process of sensory nature1 termed the cnidocil 7cn7 projects from the cnidoblast like a fine hair or cilium4 ,many points in the development and mechanism of the nematocyst are disputed1 but it is tolerably certain 7#a7 that the cnidocil is of sensory nature1 and that stimulation1 by contact with prey or in other ways1 causes a reflex discharge of the nematocyst2 7#b7 that the discharge is an explosive change whereby the in-turned thread is suddenly everted and turned inside out1 being thus shot through the opening in the outer wall of the capsule1 and forced violently into the tissues of the prey1 or1 it may be1 of an enemy2 7#c7 that the thread inflicts not merely a mechanical wound1 but instils an irritant poison1 numbing and paralysing in its action4 ,the points most in dispute are1 first1 how the explosive discharge is brought about1 whether by pressure exerted external to the capsule 7i4e4 by contraction of the cnidoblast7 or by internal pressure4 ,n4 ,iwanzov #bg has brought forward strong grounds for the latter view1 pointing out that the cnidoblast has no contractile mechanism and that measurements show discharged capsules to be on the average slightly larger than undischarged ones4 ,he believes that the capsule contains a substance which swells very rapidly when brought into contact with water1 and that in the undischarged condition the capsule has its opening closed by a plug of protoplasm 7x1 fig4 #g7 which prevents access of water to the contents2 when the cnidocil is stimulated it sets in action a mechanism or perhaps a series of chemical changes by which the plug is dissolved or removed2 as a result water penetrates into the capsule and causes its contents to swell1 with the result that the thread is everted violently4 ,a second point of dispute concerns the spot at which the poison is lodged4 ,iwanzov believes it to be contained within the thread itself before discharge1 and to be introduced into the tissues of the prey by the eversion of the thread4 ,a third point of dispute is whether the nematocysts are formed in situ1 or whether the cnidoblasts migrate with them to the region where they are most needed2 the fact that in ,hydra1 for example1 there are no interstitial cells in the tentacles1 where nematocysts are very abundant1 is certainly in favour of the view that the cnidoblasts migrate on to the tentacles from the body1 and that like the genital cells the cnidoblasts are wandering cells4 ,illustration3 ,,fig4 #g4--;,diagrams to show the structure of ,nematocysts and their mode of working4 7,after ,iwanzov47 a1 ,undischarged nematocyst4 b1 ,commencing discharge4 c1 ,discharge complete4 cn1 ,cnidocil4 ,n1 ,nucleus of cnidoblast4 o4c1 ,outer capsule4 x1 ,plug closing the opening of the outer capsule4 i4c41 ,inner capsule1 continuous with the wall of the filament1 f4 b1 ,barbs4 ,the muscular tissue consists primarily of processes from the bases of the epithelial cells1 processes which are contractile in nature and may be distinctly striated4 ,a further stage in evolution is that the muscle-cells lose their connexion with the epithelium and come to lie entirely beneath it1 forming a sub-epithelial contractile layer1 developed chiefly in the tentacles of the polyp4 ,the evolution of the ganglion-cells1 is probably similar2 an epithelial cell develops processes of nervous nature from the base1 which come into connexion with the bases of the sensory cells1 with the muscular cells1 and with the similar processes of other nerve-cells2 next the nerve-cell loses its connexion with the outer epithelium and becomes a sub-epithelial ganglion-cell which is closely connected with the muscular layer1 conveying stimuli from the sensory cells to the contractile elements4 ,the ganglion-cells of ,hydromedusae are generally very small4 ,in the polyp the nervous tissue is always in the form of a scattered plexus1 never concentrated to form a definite nervous system as in the medusa4 ,illustration3 ,from ,gegenbaur's ,elements of ,comparative ,anatomy4 ,,fig4 #h4--,vacuolated ,endoderm ,cells of cartilaginous consistence from the axis of the tentacle of a ,medusa 7,cunina74 ,the endoderm of the polyp is typically a flagellated epithelium of large cells 7fig4 #f71 from the bases of which arise contractile muscular processes lying in the plane of the transverse section of the body4 ,in different parts of the coelenteron the endoderm may be of three principal types--7#a7 digestive endoderm1 the primitive type1 with cells of large size and considerably vacuolated1 found in the hydranth2 some of these cells may become special glandular cells1 without flagella or contractile processes2 7#b7 circulatory endoderm1 without vacuoles and without basal contractile processes1 found in the hydrorhiza and hydrocaulus2 7#c7 supporting endoderm 7fig4 #h71 seen in solid tentacles as a row of cubical vacuolated cells1 occupying the axis of the tentacle1 greatly resembling notochordal tissue1 particularly that of ,amphioxus at a certain stage of development2 as a fourth variety of endodermal cells excretory cells should perhaps be reckoned1 as seen in the pores in the foot of ,hydra and elsewhere 7cf4 ,c4 ,chun1 ,,hydrozoa #a1 pp4 #cad1 #cae74 ,the mesogloea in the hydropolyp is a thin elastic layer1 in which may be lodged the muscular fibres and ganglion cells mentioned above1 but which never contains any connective tissue or skeletogenous cells or any other kind of special mesogloeal corpuscles4 ,illustration3 ,from ,allman's ,gymnoblastic ,hydroids1 by permission of the ,council of the ,ray ,society4 ,,fig4 #i4--;,colony of ,hydractinia echinata1 growing on the ,shell of a ,whelk4 ,natural size4 ,illustration3 ,from ,allman's ,gymnoblastic ,hydroids1 by permission of the ,council of the ,ray ,society4 ,,fig4 #aj4--,polyps from a ,colony of ,hydractinia1 magnified4 dz1 dactylozoid2 gz1 gastrozoid3 b1 blastostyle2 gon1 gonophores2 rh1 hydrorhiza4 #b4 ,the ,polyp-colony4--,all known hydropolyps possess the power of reproduction by budding1 and the buds produced may become either polyps or medusae4 ,the buds may all become detached after a time and give rise to separate and independent individuals1 as in the common ,hydra1 in which only polyp-individuals are produced and sexual elements are developed upon the polyps themselves2 or1 on the other hand1 the polyp-individuals produced by budding may remain permanently in connexion with the parent polyp1 in which case sexual elements are never developed on polyp-individuals but only on medusa-individuals1 and a true colony is formed4 ,thus the typical hydroid colony starts from a founder polyp1 which in the vast majority of cases is fixed1 but which may be floating1 as in ,nemopsis1 ,pelagohydra1 c4 ,the founder-polyp usually produces by budding polyp-individuals1 and these in their turn produce other buds4 ,the polyps are all non-sexual individuals whose function is purely nutritive4 ,after a time the polyps1 or certain of them1 produce by budding medusa-individuals1 which sooner or later develop sexual elements2 in some cases1 however1 the founder-polyp remains solitary1 that is to say1 does not produce polyp-buds1 but only medusa-buds1 from the first 7,corymorpha1 fig4 #c1 ,myriothela1 c474 ,in primitive forms the medusa-individuals are set free before reaching sexual maturity and do not contribute anything to the colony4 ,in other cases1 however1 the medusa-individuals become sexually mature while still attached to the parent polyp1 and are then not set free at all1 but become appanages of the hydroid colony and undergo degenerative changes leading to reduction and even to complete obliteration of their original medusan structure4 ,in this way the hydroid colony becomes composed of two portions of different function1 the nutritive trophosome1 composed of non-sexual polyps1 and the reproductive gonosome1 composed of sexual medusa-individuals1 which never exercise a nutritive function while attached to the colony4 ,as a general rule polyp-buds are produced from the hydrorhiza and hydrocaulus1 while medusa-buds are formed on the hydranth4 ,in some cases1 however1 medusa-buds are formed on the hydrorhiza1 as in ,hydrocorallines4 ,in such a colony of connected individuals1 the exact limits of the separate persons are not always clearly marked out4 ,hence it is necessary to distinguish between1 first1 the zooids1 indicated in the case of the polyps by the hydranths1 each with mouth and tentacles2 and1 secondly1 the coenosarc1 or common flesh1 which cannot be assigned more to one individual than another1 but consists of a more or less complicated network of tubes1 corresponding to the hydrocaulus and hydrorhiza of the primitive independent polyp-individual4 ,the coenosarc constitutes a system by which the digestive cavity of any one polyp is put into communication with that of any other individual either of the trophosome or gonosome4 ,in this manner the food absorbed by one individual contributes to the welfare of the whole colony1 and the coenosarc has the function of circulating and distributing nutriment through the colony4 ,the hydroid colony shows many variations in form and architecture which depend simply upon differences in the methods in which polyps are budded4 ,illustration3 ,after ,hincks1 ,forbes1 and ,browne4 ,a and ,b modified from ,hincks2 ,c modified from ,forbes's ,brit4 ,naked-eyed ,medusae4 ,,fig4 #aa4--,lar sabellarum and two stages of its ,medusa1 ,willia stellata4 ,a1 colony of ,lar2 ,b and ,c1 young and adult medusae4 ,in the first place1 buds may be produced only from the hydrorhiza1 which grows out and branches to form a basal stolon1 typically net-like1 spreading over the substratum to which the founder-polyp attached itself4 ,from the stolon the daughter-polyps grow up vertically4 ,the result is a spreading or creeping colony1 with the coenosarc in the form of a root-like horizontal network 7fig4 #e1 ,b2 #aa1 ,a74 ,such a colony may undergo two principal modifications4 ,the meshes of the basal network may become very small or virtually obliterated1 so that the coenosarc becomes a crust of tubes tending to fuse together1 and covered over by a common perisarc4 ,encrusting colonies of this kind are seen in ,clava squamata 7fig4 #e1 ,a7 and ,hydractinia 7figs4 #i1 #aj71 the latter having the perisarc calcified4 ,a further very important modification is seen when the tubes of the basal perisarc do not remain spread out in one plane1 but grow in all planes forming a felt-work2 the result is a massive colony1 such as is seen in the so-called ,hydrocorallines 7fig4 #fj71 where the interspaces between the coenosarcal tubes are filled up with calcareous matter1 or coenosteum1 replacing the chitinous perisarc4 ,the result is a stony1 solid mass1 which contributes to the building up of coral reefs4 ,in massive colonies of this kind no sharp distinction can be drawn between hydrorhiza and hydrocaulus in the coenosarc2 it is practically all hydrorhiza4 ,massive colonies may assume various forms and are often branching or tree-like4 ,a further peculiarity of this type of colony is that the entire coenosarcal complex is covered externally by a common layer of ectoderm2 it is not clear how this covering layer is developed4 ,illustration3 ,,fig4 #ab4--;,colony of ,bougainvillea fruticosa1 natural size1 attached to the underside of a piece of floating timber4 7,after ,allman47 ,in the second place1 the buds may be produced from the hydrocaulus1 growing out laterally from it2 the result is an arborescent1 tree-like colony 7figs4 #ab1 #ac74 ,budding from the hydrocaulus may be combined with budding from the hydrorhiza1 so that numerous branching colonies arise from a common basal stolon4 ,in the formation of arborescent colonies1 two sharply distinct types of budding are found1 which are best described in botanical terminology as the monopodial or racemose1 and the sympodial or cymose types respectively2 each is characteristic of one of the two sub-orders of the ,hydroidea1 the ,gymnoblastea and ,calyptoblastea4 ,in the monopodial method 7figs4 #ab1 #ad7 the founder-polyp is1 theoretically1 of unlimited growth in a vertical direction1 and as it grows up it throws out buds right and left alternately1 so that the first bud produced by it is the lowest down1 the second bud is above the first1 the third above this again1 and so on4 ,each bud produced by the founder proceeds to grow and to bud in the same way as the founder did1 producing a side branch of the main stem4 ,hence1 in a colony of gymnoblastic hydroids1 the oldest polyp of each system1 that is to say1 of the main stem or of a branch1 is the topmost polyp2 the youngest polyp of the system is the one nearest to the topmost polyp2 and the axis of the system is a true axis4 ,illustration3 ,,fig4 #ac4--,portion of colony of ,bougainvillea fruticosa 7,anthomedusae-,gymnoblastea7 more magnified4 7,from ,lubbock1 after ,allman47 ,illustration3 ,,fig4 #ad4--;,diagrams of the monopodial method of budding1 shown in five stages 7#a-e74 ,f1 the founder-polyp2 #a1 #b1 #c1 #d1 the succession of polyps budded from the founder-polyp2 a1 b1 c1 the succession of polyps budded from #a2 a1 b1 polyps budded from #b2 a1 polyp budded from #c4 ,in the sympodial method of budding1 on the other hand1 the founder-polyp is of limited growth1 and forms a bud from its side1 which is also of limited growth1 and forms a bud in its turn1 and so on 7figs4 #ae1 #af74 ,hence1 in a colony of calyptoblastic hydroids1 the oldest polyp of a system is the lowest2 the youngest polyp is the topmost one2 and the axis of the system is a false axis composed of portions of each of the consecutive polyps4 ,in this method of budding there are two types4 ,in one1 the biserial type 7fig4 #ae71 the polyps produce buds right and left alternately1 so that the hydranths are arranged in a zigzag fashion1 forming a scorpioid cyme1 as in ,obelia and ,sertularia4 ,in the other1 the uniserial type 7fig4 #af71 the buds are formed always on the same side1 forming a helicoid cyme1 as in ,hydrallmania1 according to ,h4 ,driesch1 in which1 however1 the primitively uniserial arrangement becomes masked later by secondary torsions of the hydranths4 ,illustration3 ,,fig4 #ae4--;,diagram of sympodial budding1 biserial type1 shown in five stages 7#a-e74 ,f1 founder-polyp2 #a1 #b1 #c1 #d1 #e1 #f1 succession of polyps budded from the founder2 a1 b1 c1 second series of polyps budded from the founder2 a1 b1 series budded from #c4 ,illustration3 ,,fig4 #af4--;,diagram of sympodial budding1 uniserial type1 shown in four stages 7#a-d74 ,f1 founder-polyp2 #a1 #b1 #c1 succession of polyps budded from the founder4 ,in a colony formed by sympodial budding1 a polyp always produces first a bud1 which contributes to the system to which it belongs1 i4e4 continues the stem or branch of which its parent forms a part4 ,the polyp may then form a second bud1 which becomes the starting point of a new system1 the beginning1 that is1 of a new branch2 and even a third bud1 starting yet another system1 may be produced from the same polyp4 ,hence the colonies of ,calyptoblastea may be complexly branched1 and the budding may be biserial throughout1 uniserial throughout1 or partly one1 partly the other4 ,thus in ,plumularidae 7figs4 #ag1 #ah7 there is formed a main stem by biserial budding2 each polyp on the main stem forms a second bud1 which usually forms a side branch or pinnule by uniserial budding4 ,in this way are formed the familiar feathery colonies of ,plumularia1 in which the pinnules are all in one plane1 while in the allied ,antennularia the pinnules are arranged in whorls round the main biserial stem4 ,the pinnules never branch again1 since in the uniserial mode of budding a polyp never forms a second polyp-bud4 ,on the other hand1 a polyp on the main stem may form a second bud which1 instead of forming a pinnule by uniserial budding1 produces by biserial budding a branch1 from which pinnules arise as from the main stem 7fig4 #ah--c1 #f74 ,or a polyp on the main stem1 after having budded a second time to form a pinnule1 may give rise to a third bud1 which starts a new biserial system1 from which uniserial pinnules arise as from the main stem--type of ,aglaophenia 7fig4 #ai74 ,the laws of budding in hydroids have been worked out in an interesting manner by ,h4 ,driesch #ac1 to whose memoirs the reader must be referred for further details4 ,illustration3 ,,fig4 #ag4--;,diagram of sympodial budding1 simple unbranched ,plumularia-type4 ,f1 founder2 #a-h1 main axis formed by biserial budding from founder2 a-e1 pinnule formed by uniserial budding from founder2 a-d1 branch formed by similar budding from #a2 a-d from #b1 and so forth4 ,individualization of ,polyp-,colonies4--,as in other cases where animal colonies are formed by organic union of separate individuals1 there is ever a tendency for the polyp-colony as a whole to act as a single individual1 and for the members to become subordinated to the needs of the colony and to undergo specialization for particular functions1 with the result that they simulate organs and their individuality becomes masked to a greater or less degree4 ,perhaps the earliest of such specializations is connected with the reproductive function4 ,whereas primitively any polyp in a colony may produce medusa-buds1 in many hydroid colonies medusae are budded only by certain polyps termed blastostyles 7fig4 #aj1 b74 ,at first not differing in any way from other polyps 7fig4 #e71 the blastostyles gradually lose their nutritive function and the organs connected with it2 the mouth and tentacles disappear1 and the blastostyle obtains the nutriment necessary for its activity by way of the coenosarc4 ,in the ,calyptoblastea1 where the polyps are protected by special capsules of the perisarc1 the gonothecae enclosing the blastostyles differ from the hydrothecae protecting the hydranths 7fig4 #ed74 ,illustration3 ,,fig4 #ah4--;,diagram showing method of branching in the ,plumularia-type2 compare with fig4 #ag4 ,polyps #c and #f1 instead of producing uniserial pinnules1 have produced biserial branches 7#c1 #c1 #c1 #cd2 #f-f71 which give off uniserial branches in their turn4 ,in other colonies the two functions of the nutritive polyp1 namely1 capture and digestion of food1 may be shared between different polyps 7fig4 #aj74 ,one class of polyps1 the dactylozoids 7dz71 lose their mouth and stomach1 and become elongated and tentacle-like1 showing great activity of movement4 ,another class1 the gastrozoids 7gz71 have the tentacles reduced or absent1 but have the mouth and stomach enlarged4 ,the dactylozoids capture food1 and pass it on to the gastrozoids1 which swallow and digest it4 ,illustration3 ,,fig4 #ai4--;,diagram showing method of branching in the ,aglaophenia-type4 ,polyp #g has produced as its first bud1 #h2 as its second bud1 a#g1 which starts a uniserial pinnule2 and as a third bud ,i#g1 which starts a biserial branch 7,,ii#g-,,vi#g7 that repeats the structure of the main stem and gives off pinnules4 ,the main stem is indicated by---1 the new stem by 4 ,besides the three types of individual above mentioned1 there are other appendages of hydroid colonies1 of which the individuality is doubtful4 ,such are the guard-polyps 7machopolyps7 of ,plumularidae1 which are often regarded as individuals of the nature of dactylozoids1 but from a study of the mode of budding in this hydroid family ,driesch concluded that the guard-polyps were not true polyp-individuals1 although each is enclosed in a small protecting cup of the perisarc1 known as a nematophore4 ,again1 the spines arising from the basal crust of ,podocoryne have been interpreted by some authors as reduced polyps4 #c4 ,the ,medusa4--,in the ,hydromedusae the medusa-individual occurs1 as already stated1 in one of two conditions1 either as an independent organism leading a true life in the open seas1 or as a subordinate individuality in the hydroid colony1 from which it is never set free2 it then becomes a mere reproductive appendage or gonophore1 losing successively its organs of sense1 locomotion and nutrition1 until its medusoid nature and organization become scarcely recognizable4 ,hence it is convenient to consider the morphology of the medusa from these two aspects4 7a7 ,the ,medusa as an ,independent ,organism4--,the general structure and characteristics of the medusa are described elsewhere 7see articles ,,hydrozoa and ,,medusa71 and it is only necessary here to deal with the peculiarities of the ,hydromedusa4 ,illustration3 ,from ,allman's ,gymnoblastic ,hydroids1 by permission of the ,council of the ,ray ,society4 ,,fig4 #bj4--;,cladonema radiatum1 the medusa walking on the basal branches of its tentacles 7t71 which are turned up over the body4 ,illustration3 ,from ,allman's ,gymnoblastic ,hydroids1 by permission of the ,council of the ,ray ,society4 ,,fig4 #ba4--;,clavatella prolifera1 ambulatory medusa4 t1 tentacles2 oc1 ocelli4 ,as regards habit of life the vast majority of ,hydromedusae are pelagic organisms1 floating on the surface of the open sea1 propelling themselves feebly by the pumping movements of the umbrella produced by contraction of the sub-umbral musculature1 and capturing their prey with their tentacles4 ,the genera ,cladonema 7fig4 #bj7 and ,clavatella 7fig4 #ba71 however1 are ambulatory1 creeping forms1 living in rock-pools and walking1 as it were1 on the tips of the proximal branches of each of the tentacles1 while the remaining branches serve for capture of food4 ,cladonema still has the typical medusan structure1 and is able to swim about1 but in ,clavatella the umbrella is so much reduced1 that swimming is no longer possible4 ,the remarkable medusa ,mnestra parasites is ecto-parasitic throughout life on the pelagic mollusc ,phyllirrhoe1 attached to it by the sub-umbral surface1 and its tentacles have become rudimentary or absent4 ,it is interesting to note that ,mnestra has been shown by ,j4 ,w4 ,fewkes #ae and ,r4 ,t4 ,gnther #ai to belong to the same family 7,cladonemidae7 as ,cladonema and ,clavatella1 and it is reasonable to suppose that the non-parasitic ancestor of ,mnestra was1 like the other two genera1 an ambulatory medusa which acquired louse-like habits4 ,in some species of the genus ,cunina 7,narcomedusae7 the youngest individuals 7actinulae7 are parasitic on other medusae 7see below71 but in later life the parasitic habit is abandoned4 ,no other instances are known of sessile habit in ,hydromedusae4 ,illustration3 ,after ,e4 ,t4 ,browne1 from ,proc4 ,zool4 ,soc4 of ,london4 ,,fig4 #bb4--;,corymorpha nutans1 adult female ,medusa4 ,magnified #aj diameters4 ,the external form of the ,hydromedusae varies from that of a deep bell or thimble1 characteristic of the ,anthomedusae1 to the shallow saucer-like form characteristic of the ,leptomedusae4 ,it is usual for the umbrella to have an even1 circular1 uninterrupted margin2 but in the order ,narcomedusae secondary down-growths between the tentacles produce a lobed1 indented margin to the umbrella4 ,the marginal tentacles are rarely absent in non-parasitic forms1 and are typically four in number1 corresponding to the four perradii marked by the radial canals4 ,interradial tentacles may be also developed1 so that the total number present may be increased to eight or to an indefinitely large number4 ,in ,willia1 ,geryonia1 c41 however1 the tentacles and radial canals are on the plan of six instead of four 7figs4 #aa and #bf74 ,on the other hand1 in some cases the tentacles are less in number than the perradii2 in ,corymorpha 7figs4 #c and #bb7 there is but a single tentacle1 while two are found in ,amphinema and ,gemmaria 7,anthomedusae71 and in ,solmundella bitentaculata 7fig4 #fg7 and ,aeginopsis hensenii 7fig4 #bc7 7,narcomedusae74 ,the tentacles also vary considerably in other ways than in number3 first1 in form1 being usually simple1 with a basal bulb1 but in ,cladonemidae they are branched1 often in complicated fashion2 secondly1 in grouping1 being usually given off singly1 and at regular intervals from the margin of the umbrella1 but in ,margelidae and in some ,trachomedusae they are given off in tufts or bunches 7fig4 #bd72 thirdly1 in position and origin1 being usually implanted on the extreme edge of the umbrella1 but in ,narcomedusae they become secondarily shifted and are given off high up on the ex-umbrella 7figs4 #bc and #be72 and1 fourthly1 in structure1 being hollow or solid1 as in the polyp4 ,in some medusae1 for instance1 the remarkable deep-sea family ,pectyllidae1 the tentacles may bear suckers1 by which the animal may attach itself temporarily4 ,it should be mentioned finally that the tentacles are very contractile and extensible1 and may therefore present themselves1 in one and the same individual1 as long1 drawn-out threads1 or in the form of short corkscrew-like ringlets2 they may stream downwards from the sub-umbrella1 or be held out horizontally1 or be directed upwards over the ex-umbrella 7fig4 #bc74 ,each species of medusa usually has a characteristic method of carrying its tentacles4 ,illustration3 ,after ,o4 ,maas1 ,die craspedoten ,medusen der ,plankton ,expedition1 by permission of ,lipsius and ,tischer4 ,,fig4 #bc4--;,aeginopsis hensenii1 slightly magnified1 showing the manner in which the tentacles are carried in life4 ,illustration3 ,after ,o4 ,maas1 ,craspedoten ,medusen der ,siboga-,expedition1 by permission of ,e4 ,s4 ,brill ,co4 ,,fig4 #bd4--,rathkea octonemalis4 ,the sub-umbrella invariably shows a velum as an inwardly projecting ridge or rim at its margin1 within the circle of tentacles2 hence the medusae of this sub-class are termed craspedote4 ,the manubrium is absent altogether in the fresh-water medusa ,limnocnida1 in which the diameter of the mouth exceeds half that of the umbrella2 on the other hand1 the manubrium may attain a great length1 owing to the centre of the sub-umbrella with the stomach being drawn into it1 as it were1 to form a long proboscis1 as in ,geryonia4 ,the mouth may be a simple1 circular pore at the extremity of the manubrium1 or by folding of the edges it may become square or shaped like a ,maltese cross1 with four corners and four lips4 ,the corners of the mouth may then be drawn out into lobes or lappets1 which may have a branched or fringed outline 7fig4 #bg71 and in ,margelidae the subdivisions of the fringe simulate tentacles 7fig4 #bd74 ,illustration3 ,after ,o4 ,maas1 ,medusae1 in ,prince of ,monaco's series4 ,,fig4 #be4--;,aeginura grimaldii4 ,the internal anatomy of the ,hydromedusae shows numerous variations4 ,the stomach may be altogether lodged in the manubrium1 from which the radial canals then take origin directly as in ,geryonia 7,trachomedusae72 it may be with or without gastric pouches4 ,the radial canals may be simple or branched1 primarily four1 rarely six in number4 ,the ring-canal is drawn out in ,narcomedusae into festoons corresponding with the lobes of the margin1 and may be obliterated altogether 7,solmaris74 ,in this order the radial canals are represented only by wide gastric pouches1 and in the family ,solmaridae are suppressed altogether1 so that the tentacles and the festoons of the ring-canal arise directly from the stomach4 ,in ,geryonia1 centripetal canals1 ending blindly1 arise from the ring-canal and run in a radial direction towards the centre of the umbrella 7fig4 #bf74 ,histology of the ,hydromedusa4--,the histology described above for the polyp may be taken as the primitive type1 from which that of the medusa differs only in greater elaboration and differentiation of the cell-elements1 which are also more concentrated to form distinct tissues4 ,illustration3 ,,fig4 #bf4--;,carmarina 7,geryonia7 hastata1 one of the ,trachomedusae4 7,after ,haeckel47 a1 ,nerve ring1 a1 ,radial nerve4 b1 ,tentaculocyst4 c1 ,circular canal4 e1 ,radiating canal1 g4 ,ovary4 h1 ,peronia or cartilaginous process ascending from the cartilaginous margin of the disk centripetally in the outer surface of the jelly-like disk2 six of these are perradial1 six interradial1 corresponding to the twelve solid larval tentacles1 resembling those of ,cunina4 k1 ,dilatation 7stomach7 of the manubrium4 l1 ,jelly of the disk4 p1 ,manubrium4 t1 ,tentacle 7hollow and tertiary1 i4e4 preceded by six perradial and six interradial solid larval tentacles74 u1 ,cartilaginous margin of the disk covered by thread-cells4 v4 ,velum4 ,the ectoderm furnishes the general epithelial covering of the body1 and the muscular tissue1 nervous system and sense-organs4 ,the external epithelium is flat on the ex-umbral surface1 more columnar on the sub-umbral surface1 where it forms the muscular tissue of the sub-umbrella and the velum4 ,the nematocysts of the ectoderm may be grouped to form batteries on the tentacles1 umbrellar margin and oral lappets4 ,in places the nematocysts may be crowded so thickly as to form a tough1 supporting1 chondral tissue1 resembling cartilage1 chiefly developed at the margin of the umbrella and forming streaks or bars supporting the tentacles 7,tentakelspangen1 peronia7 or the tentaculocysts 7,gehrspangen1 otoporpae74 ,illustration3 ,after ,o4 ,maas in ,results of the ,albatross ,expedition1 ,museum of ,comparative ,zoology1 ,cambridge1 ,mass41 ,u4,s4,a4 ,,fig4 #bg4--,stomotoca divisa1 one of the ,tiaridae 7,anthomedusae74 ,the muscular tissue of the ,hydromedusae is entirely ectodermal4 ,the muscle-fibres arise as processes from the bases of the epithelial cells2 such cells may individually become sub-epithelial in position1 as in the polyp2 or1 in places where muscular tissue is greatly developed1 as in the velum or sub-umbrella1 the entire muscular epithelium may be thrown into folds in order to increase its surface1 so that a deeper sub-epithelial muscular layer becomes separated completely from a more superficial body-epithelium4 ,in its arrangement the muscular tissue forms two systems3 the one composed of striated fibres arranged circularly1 that is to say1 concentrically round the central axis of the umbrella2 the other of non-striated fibres running longitudinally1 that is to say1 in a radial direction from1 or 7in the manubrium7 parallel to1 the same ideal axis4 ,the circular system is developed continuously over the entire sub-umbral surface1 and the velum represents a special local development of this system1 at a region where it is able to act at the greatest mechanical advantage in producing the contractions of the umbrella by which the animal progresses4 ,the longitudinal system is discontinuous1 and is subdivided into proximal1 medial and distal portions4 ,the proximal portion forms the retractor muscles of the manubrium1 or proboscis1 well developed1 for example1 in ,geryonia4 ,the medial portion forms radiating tracts of fibres1 the so-called bell-muscles running underneath1 and parallel to1 the radial canals2 when greatly developed1 as in ,tiaridae1 they form ridges1 so-called mesenteries1 projecting into the sub-umbral cavity4 ,the distal portions form the muscles of the tentacles4 ,in contrast with the polyp1 the longitudinal muscle-system is entirely ectodermal1 there being no endodermal muscles in craspedote medusae4 ,illustration3 ,,fig4 #bh4--,muscular ,cells of ,medusae 7,lizzia74 ,the uppermost is a purely muscular cell from the sub-umbrella2 the two lower are epidermo-muscular cells from the base of a tentacle2 the upstanding nucleated portion forms part of the epidermal mosaic on the free surface of the body4 7,after ,hertwig47 ,the nervous system of the medusa consists of sub-epithelial ganglion-cells1 which form1 in the first place1 a diffuse plexus of nervous tissue1 as in the polyp1 but developed chiefly on the sub-umbral surface2 and which are concentrated1 in the second place1 to form a definite central nervous system1 never found in the polyp4 ,in ,hydromedusae the central nervous system forms two concentric nerve-rings at the margin of the umbrella1 near the base of the velum4 ,one1 the upper or ex-umbral nerve-ring1 is derived from the ectoderm on the ex-umbral side of the velum2 it is the larger of the two rings1 containing more numerous but smaller ganglion-cells1 and innervates the tentacles4 ,the other1 the lower or sub-umbral nerve-ring1 is derived from the ectoderm on the sub-umbral side of the velum2 it contains fewer but larger ganglion-cells and innervates the muscles of the velum 7see diagram in article ,,medusae74 ,the two nerve-rings are connected by fibres passing from one to the other4 ,illustration3 ,after ,o4 ,maas1 ,craspedoten ,medusen der ,siboga ,expedition1 by permission of ,e4 ,s4 ,brill ,co4 ,,fig4 #bi4--,tiaropsis rosea 7,ag4 and ,mayer7 showing the eight adradial ,statocysts1 each close to an ,ocellus4 ,cf4 fig4 #cj4 ,the sensory cells are slender epithelial cells1 often with a cilium or stiff protoplasmic process1 and should perhaps be regarded as the only ectoderm-cells which retain the primitive ciliation of the larval ectoderm1 otherwise lost in all ,hydrozoa4 ,the sense-cells form1 in the first place1 a diffuse system of scattered sensory cells1 as in the polyp1 developed chiefly on the manubrium1 the tentacles and the margin of the umbrella1 where they form a sensory ciliated epithelium covering the nerve-centres2 in the second place1 the sense-cells are concentrated to form definite sense-organs1 situated always at the margin of the umbrella1 hence often termed marginal bodies4 ,the possession of definite sense-organs at once distinguishes the medusa from the polyp1 in which they are never found4 ,the sense-organs of medusae are of two kinds--first1 organs sensitive to light1 usually termed ocelli 7fig4 #bi72 secondly1 organs commonly termed otocysts1 on account of their resemblance to the auditory vesicles of higher animals1 but serving for the sense of balance and orientation1 and therefore given the special name of statocysts 7fig4 #cj74 ,the sense-organs may be tentaculocysts1 i4e4 modifications of a tentacle1 as in ,trachylinae1 or developed from the margin of the umbrella1 in no connexion with a tentacle 7or1 if so connected1 not producing any modification in the tentacle71 as in ,leptolinae4 ,in ,hydromedusae the sense-organs are always exposed at the umbrellar margin 7hence ,gymnophthalmata71 while in ,scyphomedusae they are covered over by flaps of the umbrellar margin 7hence ,steganophthalmata74 ,illustration3 ,modified after ,linko1 ,traveaux ,soc4 ,imp4 ,nat41 ,st4 ,petersbourg1 xxix4 ,,fig4 #cj4--,section of a ,statocyst and ,ocellus of ,tiaropsis diademata2 cf4 fig4 #bi4 ex1 ,ex-umbral ectoderm4 sub1 ,sub-umbral ectoderm4 c4c1 ,circular canal4 v1 ,velum4 st4e1 ,cavity of statocyst4 con1 ,concrement-cell with otolith4 ,the statocysts present in general the structure of either a knob or a closed vesicle1 composed of 7#a7 indifferent supporting epithelium3 7#b7 sensory1 so-called auditory epithelium of slender cells1 each bearing at its free upper end a stiff bristle and running out at its base into a nerve-fibre2 7#c7 concrement-cells1 which produce intercellular concretions1 so-called otoliths4 ,by means of vibrations or shocks transmitted through the water1 or by displacements in the balance or position of the animal1 the otoliths are caused to impinge against the bristles of the sensory cells1 now on one side1 now on the other1 causing shocks or stimuli which are transmitted by the basal nerve-fibre to the central nervous system4 ,two stages in the development of the otocyst can be recognized1 the first that of an open pit on a freely-projecting knob1 in which the otoliths are exposed1 the second that of a closed vesicle1 in which the otoliths are covered over4 ,further1 two distinct types of otocyst can be recognized in the ,hydromedusae3 that of the ,leptolinae1 in which the entire organ is ectodermal1 concrement-cells and all1 and the organ is not a tentaculocyst2 and that of the ,trachylinae1 in which the organ is a tentaculocyst1 and the concrement-cells are endodermal1 derived from the endoderm of the modified tentacle1 while the rest of the organ is ectodermal4 ,illustration3 ,modified after ,o4 and ,r1 ,hertwig1 ,nervensystem und ,sinnesorgane der ,medusen1 by permission of ,f4 ,c4 ,w4 ,vogel4 ,,fig4 #ca4--,section of a ,statocyst of ,mitrocoma annae4 sub1 ,sub-umbral ectoderm4 c4c1 ,circular canal4 v1 ,velum4 st4c14 ,cavity of statocyst4 con1 ,concrement-cell with otolith4 ,illustration3 ,modified after ,o4 and ,r1 ,hertwig1 ,nervensystem und ,sinnesorgane der ,medusen1 by permission of ,f4 ,c4 ,w4 ,vogel4 ,,fig4 #cb4--,section of a ,statocyst of ,phialidium4 ex1 ,ex-umbral ectoderm4 sub1 ,sub-umbral ectoderm4 v1 ,velum4 st4c1 ,cavity of statocyst4 con1 ,concrement-cell with otolith4 ,illustration3 ,modified after ,o4 and ,r1 ,hertwig1 ,nervensystem und ,sinnesorgane der ,medusen1 by permission of ,f4 ,c4 ,w4 ,vogel4 ,,fig4 #cc4--,optical ,section of a ,statocyst of ,octorchis4 con1 ,concrement-cell with otolith4 st4c1 ,cavity of statocyst4 ,in the ,leptolinae the otocysts are seen in their first stage in ,mitrocoma annae 7fig4 #ca7 and ,tiaropsis 7figs4 #bi1 #cj7 as an open pit at the base of the velum1 on its sub-umbral side4 ,the pit has its opening turned towards the sub-umbral cavity1 while its base or fundus forms a bulge1 more or less pronounced1 on the ex-umbral side of the velum4 ,at the fundus are placed the concrement-cells with their conspicuous otoliths 7con7 and the inconspicuous auditory cells1 which are connected with4 the sub-umbral nerve-ring4 ,from the open condition arises the closed condition very simply by closing up of the aperture of the pit4 ,we then find the typical otocyst of the ,leptomedusae1 a vesicle bulging on the ex-umbral side of the velum 7figs4 #cb1 #cc74 ,the otocysts are placed on the outer wall of the vesicle 7the fundus of the original pit7 or on its sides2 their arrangement and number vary greatly and furnish useful characters for distinguishing genera4 ,the sense-cells are innervated1 as before1 from the sub-umbral nerve-ring4 ,the inner wall of the vesicle 7region of closure7 is frequently thickened to form a so-called sense-cushion1 apparently a ganglionic offshoot from the sub-umbral nerve-ring4 ,in many ,leptomedusae the otocysts are very small1 inconspicuous and embedded completely in the tissues2 hence they may be easily overlooked in badly-preserved material1 and perhaps are present in many cases where they have been said to have been wanting4 ,illustration3 ,after ,o4 and ,r1 ,hertwig1 ,nervensystem und ,sinnesorgane der ,medusen1 by permission of ,f4 ,c4 ,w4 ,vogel4 ,,fig4 #cd4--,tentaculocyst 7statorhabd7 of ,cunina solmaris4 n4c1 ,nerve-cushion2 end1 endodermal concrement-cells2 con1 otolith4 ,illustration3 ,after ,o4 and ,r1 ,hertwig1 ,nervensystem und ,sinnesorgane der ,medusen1 by permission of ,f4 ,c4 ,w4 ,vogel4 ,,fig4 #ce4--,tentaculocyst of ,cunina lativentris4 ect1 ,ectoderm4 n4c1 ,nerve-cushion4 end1 ,endodermal concrement-cells4 con1 ,otolith4 ,in the ,trachylinae the simplest condition of the otocyst is a freely projecting club1 a so-called statorhabd 7figs4 #cd1 #ce71 representing a tentacle greatly reduced in size1 covered with sensory ectodermal epithelium 7ect471 and containing an endodermal core 7end471 which is at first continuous with the endoderm of the ring-canal1 but later becomes separated from it4 ,in the endoderm large concretions are formed 7con474 ,other sensory cells with long cilia cover a sort of cushion 7n4c47 at the base of the club2 the club may be long and the cushion small1 or the cushion large and the club small4 ,the whole structure is innervated1 like the tentacles1 from the ex-umbral nerve-ring4 ,an advance towards the second stage is seen in such a form as ,rhopalonema 7fig4 #cf71 where the ectoderm of the cushion rises up in a double fold to enclose the club in a protective covering forming a cup or vesicle1 at first open distally2 finally the opening closes and the closed vesicle may sink inwards and be found far removed from the surface1 as in ,geryonia 7fig4 #cg74 ,illustration3 ,,fig4 #cf4--,simple tentaculocyst of ,rhopalonema velatum4 ,the process carrying the otolith or concretion hk1 formed by endoderm cells1 is enclosed by an upgrowth forming the vesicle1 which is not yet quite closed in at the top4 7,after ,hertwig47 ,the ocelli are seen in their simplest form as a pigmented patch of ectoderm1 which consists of two kinds of cells--7#a7 pigment-cells1 which are ordinary indifferent cells of the epithelium containing pigment-granules1 and 7#b7 visual cells1 slender sensory epithelial cells of the usual type1 which may develop visual cones or rods at their free extremity4 ,the ocelli occur usually either on the inner or outer sides of the tentacles2 if on the inner side1 the tentacle is turned upwards and carried over the ex-umbrella1 so as to expose the ocellus to the light2 if the ocellus be on the outer side of a tentacle1 two nerves run round the base of the tentacle to it4 ,in other cases ocelli may occur between tentacles1 as in ,tiaropsis 7fig4 #bi74 ,the simple form of ocellus described in the foregoing paragraph may become folded into a pit or cup1 the interior of which becomes filled with a clear gelatinous secretion forming a sort of vitreous body4 ,the distal portion of the vitreous body may project from the cavity of the cup1 forming a non-cellular lens as in ,lizzia 7fig4 #bh74 ,beyond this simple condition the visual organs of the ,hydromedusae do not advance1 and are far from reaching the wonderful development of the eyes of ,scyphomedusae 7,charybdaea74 ,illustration3 ,after ,o4 and ,r1 ,hertwig1 ,nervensystem und ,sinnesorgane der ,medusen1 by permission of ,f4 ,c4 ,w4 ,vogel4 ,,fig4 #cg4--,section of statocyst of ,geryonia 7,carmarina hastata74 st4c1 ,statocyst containing the minute tentaculocyst4 nr#a1 ,ex-umbral nerve-ring4 nr#b1 ,sub-umbral nerve-ring4 ex1 ,ex-umbral ectoderm4 sub1 ,sub-umbral ectoderm4 c4c1 ,circular canal4 v1 ,velum4 ,besides the ordinary type of ocellus just described1 there is found in one genus 7,tiaropsis7 a type of ocellus in which the visual elements are inverted1 and have their cones turned away from the light1 as in the human retina 7fig4 #cj74 ,in this case the pigment-cells are endodermal1 forming a cup of pigment in which the visual cones are embedded4 ,a similar ocellus is formed in ,aurelia among the ,scyphomedusae 7q4v474 ,other sense organs of ,hydromedusae are the so-called sense-clubs or cordyli found in a few ,leptomedusae1 especially in those genera in which otocysts are inconspicuous or absent 7fig4 #ci74 ,each cordylus is a tentacle-like structure with an endodermal axis containing an axial cavity which may be continuous with the ring-canal1 or may be partially occluded4 ,externally the cordylus is covered1 by very flattened ectoderm1 and bears no otoliths or sense-cells1 but the base of the club rests upon the ex-umbral nerve-ring4 ,brooks regards these organs as sensory1 serving for the sense of balance1 and representing a primitive stage of the tentaculocysts of ,trachylinae2 ,linko1 on the other hand1 finding no nerve-elements connected with them1 regards them as digestive 787 in function4 ,the sense-organs of the two fresh-water medusae ,limnocodium and ,limnocnida are peculiar and of rather doubtful nature 7see ,e4 ,t4 ,browne #aj74 ,,fig4 #ch4--,ocellus of ,lizzia koellikeri4 oc1 ,pigmented ectodermal cells2 l1 lens4 7,after ,hertwig47 ,the endoderm of the medusa shows the same general types of structure as in the polyp1 described above4 ,we can distinguish 7#a7 digestive endoderm1 in the stomach1 often with special glandular elements2 7#b7 circulatory endoderm1 in the radial and ring-canals2 7#c7 supporting endoderm in the axes of the tentacles and in the endoderm-lamella2 the latter is primitively a double layer of cells1 produced by concrescence of the ex-umbral and sub-umbral layers of the coelenteron1 but it is usually found as a single layer of flattened cells 7fig4 #dj72 in ,geryonia1 however1 it remains double1 and the centripetal canals arise by parting of the two layers2 7#d7 excretory endoderm1 lining pores at the margin of the umbrella1 occurring in certain ,leptomedusae as so-called marginal tubercles1 opening1 on the one hand1 into the ring-canal and1 on the other hand1 to the exterior by marginal funnels1 which debouch into the sub-umbral cavity above the velum4 ,as has been described above1 the endoderm may also contribute to the sense-organs1 but such contributions are always of an accessory nature1 for instance1 concrement-cells in the otocysts1 pigment in the ocelli1 and never of sensory nature1 sense-cells being in all cases ectodermal4 ,the reproductive cells may be regarded as belonging primarily to neither ectoderm nor endoderm1 though lodged in the ectoderm in all ,hydromedusae4 ,as described for the polyp1 they are wandering cells capable of extensive migrations before reaching the particular spot at which they ripen4 ,in the ,hydromedusae they usually1 if not invariably1 ripen in the ectoderm1 but in the neighbourhood of the main sources of nutriment1 that is to say1 not far from the stomach4 ,hence the gonads are found on the manubrium in ,anthomedusae generally2 on the base of the manubrium1 or under the gastral pouches1 or in both these situations 7,octorchidae71 or under the radial canals1 in ,trachomedusae2 under the gastral pouches or radial canals1 in ,narcomedusae4 ,when ripe1 the germ-cells are dehisced directly to the exterior4 ,illustration3 ,after ,w4 ,k4 ,brooks1 ,journal of ,morphology1 x41 by permission of ,ginn ,co4 ,,fig4 #ci4--,section of a ,cordylus of ,laodice4 c4c1 ,circular canal4 v1 ,velum4 t1 ,tentacle4 c1 ,cordylus1 composed of flattened ectoderm ec covering a large-celled endodermal axis en4 ,hydromedusae are of separate sexes1 the only known exception being ,amphogona apsteini1 one of the ,trachomedusae 7,browne #i74 ,moreover1 all the medusae budded from a given hydroid colony are either male or female1 so that even the non-sexual polyp must be considered to have a latent sex4 7,in ,hydra1 on the other hand1 the individual is usually hermaphrodite47 ,the medusa always reproduces itself sexually1 and in some cases non-sexually also4 ,the non-sexual reproduction takes the form of fission1 budding or sporogony1 the details of which are described below4 ,buds may be produced from the manubrium1 radial canals1 ring-canal1 or tentacle-bases1 or from an aboral stolon 7,narcomedusae74 ,in all cases only medusa-buds are produced1 never polyp-buds4 ,the mesogloea of the medusa is largely developed and of great thickness in the umbrella4 ,the sub-epithelial tissues1 i4e4 the nervous and muscular cells1 are lodged in the mesogloea1 but in ,hydromedusae it never contains tissue-cells or mesogloeal corpuscles4 7b7 ,the ,medusae as a ,subordinate ,individuality4--,it has been shown above that polyps are budded only from polyps and that the medusae may be budded either from polyps or from medusae4 ,in any case the daughter-individuals produced from the buds may be imagined as remaining attached to the parent and forming a colony of individuals in organic connexion with one another1 and thus three possible cases arise4 ,the first case gives a colony entirely composed of polyps1 as in many ,hydroidea4 ,the second case gives a colony partly composed of polyp-individuals1 partly of medusa-individuals1 a possibility also realized in many colonies of ,hydroidea4 ,the third case gives a colony entirely composed of medusa-individuals1 a possibility perhaps realized in the ,siphonophora1 which will be discussed in dealing with this group4 ,illustration3 ,,fig4 #dj4--,portions of ,sections through the ,disk of ,medusae--the upper one of ,lizzia1 the lower of ,aurelia4 7,after ,hertwig47 el1 ,endoderm lamella4 m1 ,muscular processes of the ectoderm-cells in cross section4 d1 ,ectoderm4 en1 ,endoderm lining the enteric cavity4 e1 ,wandering endoderm cells of the gelatinous substance4 ,the first step towards the formation of a mixed hydroid colony is undoubtedly a hastening of the sexual maturity of the medusa-individual4 ,normally the medusae are liberated in quite an immature state2 they swim away1 feed1 grow and become adult mature individuals4 ,from the bionomical point of view1 the medusa is to be considered as a means of spreading the species1 supplementing the deficiencies of the sessile polyp4 ,it may be1 however1 that increased reproductiveness becomes of greater importance to the species than wide diffusion2 such a condition will be brought about if the medusae mature quickly and are either set free in a mature condition or remain in the shelter of the polyp-colony1 protected from risks of a free life in the open sea4 ,in this way the medusa sinks from an independent personality to an organ of the polyp-colony1 becoming a so-called medusoid gonophore1 or bearer of the reproductive organs1 and losing gradually all organs necessary for an independent existence1 namely those of sense1 locomotion and nutrition4 ,in some cases both free medusae and gonophores may be produced from the same hydroid colony4 ,this is the case in ,syncoryne mirabilis 7,allman #a1 p4 #bgh7 and in ,campanularia volubilis2 in the latter1 free medusae are produced in summer1 gonophores in winter 7,duplessis #ad74 ,again in ,pennaria1 the male medusae are set free in a state of maturity1 and have ocelli2 the female medusae remain attached and have no sense organs4 ,illustration3 ,modified from ,weismann1 ,entstehung der ,sexualzellen bei den ,hydromedusen4 ,,fig4 #da4--;,diagrams of the ,structure of the ,gonophores of various ,hydromedusae1 based on the figures of ,g4 ,j4 ,allman and ,a4 ,weismann4 ,a1 ,meconidium of ,gonothyraea4 ,b1 ,type of ,tubularia4 ,c1 ,type of ,garveia1 c4 ,d1 ,type of ,plumularia1 ,agalma1 c4 ,e1 ,type of ,coryne1 ,forskalia1 c4 ,f1 ,g1 ,h1 ,sporosacs4 ,f1 ,with simple spadix4 ,g1 ,with spadix prolonged 7,eudendrium74 ,h1 ,with spadix branched 7,cordylophora74 s4c1 ,sub-umbral cavity4 t1 ,tentacles4 c4c1 ,circular canal1 g1 ,gonads4 sp1 ,spadix4 e4l1 ,endoderm-lamella4 ex1 ,ex-umbral ectoderm4 ect1 ,ectotheca4 ,the gonophores of different hydroids differ greatly in structure from one another1 and form a series showing degeneration of the medusa-individual1 which is gradually stripped1 as it were1 of its characteristic features of medusan organization and finally reduced to the simplest structure4 ,a very early stage in the degeneration is well exemplified by the so-called meconidium of ,gonothyraea 7fig4 #da1 ,a74 ,here the medusoid1 attached by the centre of its ex-umbral surface1 has lost its velum and sub-umbral muscles1 its sense organs and mouth1 though still retaining rudimentary tentacles4 ,the gonads 7g7 are produced on the manubrium1 which has a hollow endodermal axis1 termed the spadix 7sp471 in open communication with the coenosarc of the polyp-colony and serving for the nutrition of the generative cells4 ,a very similar condition is seen in ,tubularia 7fig4 #da1 ,b71 where1 however1 the tentacles have quite disappeared1 and the circular rim formed by the margin of the umbrella has nearly closed over the manubrium leaving only a small aperture through which the embryos emerge4 ,the next step is illustrated by the female gonophores of ,cladocoryne1 where the radial and ring-canals have become obliterated by coalescence of their walls1 so that the entire endoderm of the umbrella is in the condition of the endoderm-lamella4 ,next the opening of the umbrella closes up completely and disappears1 so that the sub-umbral cavity forms a closed space surrounding the manubrium1 on which the gonads are developed2 such a condition is seen in the male gonophore of ,cladocoryne and in ,garveia 7fig4 #da1 ,c71 where1 however1 there is a further complication in the form of an adventitious envelope or ectotheca 7ect47 split off from the gonophore as a protective covering1 and not present in ,cladocoryne4 ,the sub-umbral cavity 7s4c47 functions as a brood-space for the developing embryos1 which are set free by rupture of the wall4 ,it is evident that the outer envelope of the gonophore represents the ex-umbral ectoderm 7ex471 and that the inner ectoderm lining the cavity represents the sub-umbral ectoderm of the free medusa4 ,the next step is the gradual obliteration of the sub-umbral cavity 7s4c47 by disappearance of which the sub-umbral ectoderm comes into contact with the ectoderm of the manubrium4 ,such a type is found in ,plumularia and also in ,agalma 7fig4 #da1 ,d72 centrally is seen the spadix 7sp471 bearing the generative cells 7g71 and external to these 7#a7 a layer of ectoderm representing the epithelium of the manubrium2 7#b7 the layer of sub-umbral ectoderm2 7#c7 the endoderm-lamella 7e4l472 7#d7 the ex-umbral ectoderm 7ex472 and 7#e7 there may or may not be present also an ectotheca4 ,thus the gonads are covered over by at least four layers of epithelium1 and since these are unnecessary1 presenting merely obstacles to the dehiscence of the gonads1 they gradually undergo reduction4 ,the sub-umbral ectoderm and that covering the manubrium undergo concrescence to form a single layer 7fig4 #da1 ,e71 which finally disappears altogether1 and the endoderm-lamella disappears4 ,the gonophore is now reduced to its simplest condition1 known as the sporosac 7fig4 #da1 ,f1 ,g1 ,h71 and consists of the spadix bearing the gonads covered by a single layer of ectoderm 7ex471 with or without the addition of an ectotheca4 ,it cannot be too strongly emphasized1 however1 that the sporosac should not be compared simply with the manubrium of the medusa1 as is sometimes done4 ,the endodermal spadix 7sp7 of the sporosac represents the endoderm of the manubrium2 the ectodermal lining of the sporosac 7ex47 represents the ex-umbral ectoderm of the medusa2 and the intervening layers1 together with the sub-umbral cavity1 have disappeared4 ,the spadix1 as the organ of nutrition for the gonads1 may be developed in various ways1 being simple 7fig4 #da1 ,f7 or branched 7fig4 #da1 ,h72 in ,eudendrium 7fig4 #da1 ,g7 it curls round the single large ovum4 ,illustration3 ,after ,allman1 ,gymnoblastic ,hydroids1 by permission of the ,council of the ,ray ,society4 ,,fig4 #db4--;,gonophores of ,dicoryne conferta4 ,a1 ,a male gonophore still enclosed in its ectotheca4 ,b and ,c1 ,two views of a female gonophore after liberation4 t1 ,tentacles4 ov1 ,ova1 two carried on each female gonophore4 sp1 ,testis4 ,the hydroid ,dicoryne is remarkable for the possession of gonophores1 which are ciliate and become detached and swim away by means of their cilia4 ,each such sporosac has two long tentacle-like processes thickly ciliated4 ,it has been maintained that the gonads of ,hydra represent sporosacs or gonophores greatly reduced1 with the last traces of medusoid structure completely obliterated4 ,there is1 however1 no evidence whatever for this1 the gonads of ,hydra being purely ectodermal structures1 while all medusoid gonophores have an endodermal portion4 ,hydra is1 moreover1 bisexual1 in contrast with what is known of hydroid colonies4 ,in some ,leptomedusae the gonads are formed on the radial canals and form protruding masses resembling sporosacs superficially1 but not in structure4 ,allman1 however1 regarded this type of gonad as equivalent to a sporosac1 and considered the medusa bearing them as a non-sexual organism1 a blastocheme as he termed it1 producing by budding medusoid gonophores4 ,as medusae are known to bud medusae from the radial canals there is nothing impossible in ,allman's theory1 but it cannot be said to have received satisfactory proof4 ,reproduction and ,ontogeny of the ,hydromedusae4 ,nearly every possible method of reproduction occurs amongst the ,hydromedusae4 ,in classifying methods of generation it is usual to make use of the sexual or non-sexual nature of the reproduction as a primary difference1 but a more scientific classification is afforded by the distinction between tissue-cells 7histocytes7 and germinal cells1 actual or potential 7archaeocytes71 amongst the constituent cells of the animal body4 ,in this way we may distinguish1 first1 vegetative reproduction1 the result of discontinuous growth of the tissues and cell-layers of the body as a whole1 leading to 7#a7 fission1 7#b7 autotomy1 or 7#c7 vegetative budding2 secondly1 germinal reproduction1 the result of the reproductive activity of the archaeocytes or germinal tissue4 ,in germinal reproduction the proliferating cells may be undifferentiated1 so-called primitive germ-cells1 or they may be differentiated as sexual cells1 male or female1 i4e4 spermatozoa and ova4 ,if the germ-cells are undifferentiated1 the offspring may arise from many cells or from a single cell2 the first type is 7#d7 germinal budding1 the second is 7#e7 sporogony4 ,if the germ-cells are differentiated1 the offspring arises by syngamy or sexual union of the ordinary type between an ovum and spermatozoon1 so-called fertilization1 of the ovum1 or by parthenogenesis1 i4e4 development of an ovum without fertilization4 ,the only one of these possible modes of reproduction not known to occur in ,hydromedusae is parthenogenesis4 7#a7 ,true fission or longitudinal division of an individual into two equal and similar daughter-individuals is not common but occurs in ,gastroblasta1 where it has been described in detail by ,arnold ,lang #cj4 7#b7 ,autotomy1 sometimes termed transverse fission1 is the name given to a process of unequal fission in which a portion of the body separates off with subsequent regeneration4 ,in ,tubularia by a process of decapitation the hydranths may separate off and give rise to a separate individual1 while the remainder of the body grows a new hydranth4 ,similarly in ,schizocladium portions of the hydrocaulus are cut off to form so-called spores1 which grow into new individuals 7see ,allman #a74 ,illustration3 ,much modified from ,c4 ,chun1 ,coelenterata1 in ,bronn's ,tierreich4 ,,fig4 #dc4--;,direct ,budding of ,cunina4 ,a1 ,b1 ,c1 ,e1 ,f1 ,in vertical section4 ,d1 ,sketch of external view4 st1 ,stomach4 m1 ,manubrium4 t4 ,tentacle4 s4o1 ,sense organ4 v1 ,velum4 s4c1 ,sub-umbral cavity4 n4s1 ,nervous system4 7#c7 ,vegetative budding is almost universal in the ,hydromedusae4 ,by budding is understood the formation of a new individual from a fresh growth of undifferentiated material4 ,it is convenient to distinguish buds that give rise to polyps from those that form medusae4 7a7 ,the ,polyp4--,the buds that form polyps are very simple in mode of formation4 ,four stages may be distinguished2 the first is a simple outgrowth of both layers1 ectoderm and endoderm1 containing a prolongation of the coelenteric cavity2 in the second stage the tentacles grow out as secondary diverticula from the side of the first outgrowth2 in the third stage the mouth is formed as a perforation of the two layers2 and1 lastly1 if the bud is to be separated1 it becomes nipped off from the parent polyp and begins a free existence4 7b7 ,the ,medusae4--,two types of budding must be distinguished--the direct1 so-called1 palingenetic type1 and the indirect1 so-called coenogenetic type4 ,the direct type of budding is rare1 but is seen in ,cunina and ,millepora4 ,in ,cunina there arises1 first1 a simple outgrowth of both layers1 as in a polyp-bud 7fig4 #dc1 ,a72 in this the mouth is formed distally as a perforation 7,b72 next the sides of the tube so formed bulge out laterally near the attachment to form the umbrella1 while the distal undilated portion of the tube represents the manubrium 7,c72 the umbrella now grows out into a number of lobes or lappets1 and the tentacles and tentaculocysts grow out1 the former in a notch between two lappets1 the latter on the apex of each lappet 7,d1 ,e72 finally1 the velum arises as a growth of the ectoderm alone1 the whole bud shapes itself1 so to speak1 and the little medusa is separated off by rupture of the thin stalk connecting it with the parent 7,f74 ,the direct method of medusa-budding only differs from the polyp-bud by its greater complexity of parts and organs4 ,illustration3 ,,fig4 #dd4--;,diagrams of ,medusa budding with the formation of an entocodon4 ,the endoderm is shaded1 the ectoderm left clear4 ,a1 ,b1 ,c1 ,d1 ,f1 ,successive stages in vertical section4 ,e1 ,transverse section of a stage similar to ,d4 ,gc1 ,entocodon4 s4c1 ,cavity of entocodon1 forming the future sub-umbral cavity4 st1 ,stomach4 r4c1 ,radial canal4 c4c1 ,circular canal4 e4l1 ,endoderm lamella4 m1 ,manubrium4 v1 ,velum4 t1 ,tentacle4 ,the indirect mode of budding 7figs4 #dd1 #de7 is the commonest method by which medusa-buds are formed4 ,it is marked by the formation in the bud of a characteristic structure termed the entocodon 7,knospenkern1 ,glockenkern74 ,illustration3 ,,fig4 #de4--,modifications of the method of budding shown in fig4 #dd1 with solid ,entocodon 7,gc47 and formation of an ectotheca 7ect474 ,the first stage is a simple hollow outgrowth of both body-layers 7fig4 #dd1 ,a72 at the tip of this is formed a thickening of the ectoderm1 arising primitively as a hollow ingrowth 7fig4 #dd1 ,b71 but more usually as a solid mass of ectoderm-cells 7fig4 #de1 ,a74 ,the ectodermal ingrowth is the entocodon 7,gc472 it bulges into1 and pushes down1 the endoderm at the apex of the bud1 and if solid it soon acquires a cavity 7fig4 #dd1 ,c1 s4c474 ,the cavity of the entocodon increases continually in size1 while the endoderm pushes up at the sides of it to form a cup with hollow walls1 enclosing but not quite surrounding the entocodon1 which remains in contact at its outer side with the ectoderm covering the bud 7fig4 #dd1 ,d1 v74 ,the next changes that take place are chiefly in the endoderm-cup 7fig4 #dd1 ,d1 ,e72 the cavity between the two walls of the cup becomes reduced by concrescence to form the radial canals 7r4c471 ring-canal 7c4c471 and endoderm-lamella 7e4l41 fig4 #dd1 ,e71 and at the same time the base of the cup is thrust upwards to form the manubrium 7m71 converting the cavity of the entocodon into a space which is crescentic or horse-shoe-like in section4 ,next tentacles 7t1 fig4 #dd1 ,f7 grow out from the ring-canal1 and the double plate of ectoderm on the distal side of the entocodon becomes perforated1 leaving a circular rim composed of two layers of ectoderm1 the velum 7v7 of the medusa4 ,finally1 a mouth is formed by breaking through at the apex of the manubrium1 and the now fully-formed medusa becomes separated by rupture of the stalk of the bud and swims away4 ,illustration3 ,fig4 #df4--;,diagrams to show the significance of the ,entocodon in ,medusa-buds4 7,modified from a diagram given by ,a4 ,weismann47 ,i1 ,ideally primitive method of budding1 in which the mouth is formed first 7,ia71 next the tentacles 7,ib71 and lastly the umbrella4 ,,ii1 ,method4 of ,cunina2 7a7 the mouth arises1 next the umbrella 7b71 and lastly the tentacles 7c74 ,,iii1 ,hypothetical transition from ,,ii to the indirect method with an entocodon2 the formation of the manubrium is retarded1 that of the umbrella hastened 7,i,i,ia1 b74 ,,iv1 a1 b1 c1 budding with an entocodon 7cf4 fig4 #dd74 ,v1 ,budding with a solid entocodon 7cf4 fig4 #de74 ,if the bud1 however1 is destined to give rise not to a free medusa1 but to a gonophore1 the development is similar but becomes arrested at various points1 according to the degree to which the gonophore is degenerate4 ,the entocodon is usually formed1 proving the medusoid nature of the bud1 but in sporosacs the entocodon may be rudimentary or absent altogether4 ,the process of budding as above described may be varied or complicated in various ways2 thus a secondary1 amnion-like1 ectodermal covering or ectotheca 7fig4 #de1 ,c1 ect47 may be formed over all1 as in ,garveia1 c42 or the entocodon may remain solid and without cavity until after the formation of the manubrium1 or may never acquire a cavity at all1 as described above for the gonophores4 ,phylogenetic ,significance of the ,entocodon4--,it is seen from the foregoing account of medusa-budding that the entocodon is a very important constituent of the bud1 furnishing some of the most essential portions of the medusa2 its cavity becomes the sub-umbral cavity1 and its lining furnishes the ectodermal epithelium of the manubrium and of the sub-umbral cavity as far as the edge of the velum4 ,hence the entocodon represents a precocious formation of the sub-umbral surface1 equivalent to the peristome of the polyp1 differentiated in the bud prior to other portions of the organism which must be regarded as antecedent to it in phylogeny4 ,if the three principal organ-systems of the medusa1 namely mouth1 tentacles and umbrella1 be considered in the light of phylogeny1 it is evident that the manubrium bearing the mouth must be the oldest1 as representing a common property of all the ,coelentera1 even of the gastrula embryo of all ,enterozoa4 ,next in order come the tentacles1 common to all ,cnidaria4 ,the special property of the medusa is the umbrella1 distinguishing the medusa at once from other morphological types among the ,coelentera4 ,if1 therefore1 the formation of these three systems of organs took place according to a strictly phylogenetic sequence1 we should expect them to appear in the order set forth above 7fig4 #df1 ,ia1 b1 c74 ,the nearest approach to the phylogenetic sequence is seen in the budding of ,cunina1 where the manubrium and mouth appear first1 but the umbrella is formed before the tentacles 7fig4 #df1 ,i,ia1 b1 c74 ,in the indirect or coenogenetic method of budding1 the first two members of the sequence exhibited by ,cunina change places1 and the umbrella is formed first1 the manubrium next1 and then the tentacles2 the actual mouth-perforation being delayed to the very last 7fig4 #df1 ,i,va1 b1 c74 ,hence the budding of medusae exemplifies very clearly a common phenomenon in development1 a phylogenetic series of events completely dislocated in the ontogenetic time-sequence4 ,the entocodon is to be regarded1 therefore1 not as primarily an ingrowth of ectoderm1 but rather as an upgrowth of both body-layers1 in the form of a circular rim 7,i,va71 representing the umbrellar margin2 it is comparable to the bulging that forms the umbrella in the direct method of budding1 but takes place before a manubrium is formed1 and is greatly reduced in size1 so as to become a little pit4 ,by a simple modification1 the open pit becomes a solid ectodermal ingrowth1 just as in ,teleostean fishes the hollow medullary tube1 or the auditory pit of other vertebrate embryos1 is formed at first as a solid cord of cells1 which acquires a cavity secondarily4 ,moreover1 the entocodon1 however developed1 gives rise at first to a closed cavity1 representing a closing over of the umbrella1 temporary in the bud destined to be a free medusa1 but usually permanent in the sessile gonophore4 ,as has been shown above1 the closing up of the sub-umbral cavity is one of the earliest degenerative changes in the evolution of the gonophore1 and we may regard it as the umbrellar fold taking on a protective function1 either temporarily for the bud or permanently for the gonophore4 ,to sum up1 the entocodon is a precocious formation of the umbrella1 closing over to protect the organs in the umbrellar cavity4 ,the possession of an entocodon proves the medusa-nature of the bud1 and can only be explained on the theory that gonophores are degenerate medusae1 and is inexplicable on the opposed view that medusae are derived from gonophores secondarily set free4 ,in the sporosac1 however1 the medusa-individual has become so degenerate that even the documentary proof1 so to speak1 of its medusoid nature may have been destroyed1 and only circumstantial evidence of its nature can be produced4 #d4 ,germinal ,budding4--,this method of budding is commonly described as budding from a single body-layer1 instead of from both layers4 ,the layer that produces the bud is invariably the ectoderm1 i4e4 the layer in which1 in ,hydromedusae1 the generative cells are lodged2 and in some cases the buds are produced in the exact spot in which later the gonads appear4 ,from these facts1 and from those of the sporogony1 to be described below1 we may regard budding to this type as taking place from the germinal epithelium rather than from ordinary ectoderm4 7a7 ,the ,polyp4--,budding from the ectoderm alone has been described by ,a4 ,lang #bi in ,hydra and other polyps4 ,the tissues of the bud become differentiated into ectoderm and endoderm1 and the endoderm of the bud becomes secondarily continuous with that of the parent1 but no part of the parental endoderm contributes to the building up of the daughter-polyp4 ,lang regarded this method of budding as universal in polyps1 a notion disproved by ,o4 ,seeliger #eb who went to the opposite extreme and regarded the type of budding described by ,lang as non-existent4 ,in view1 however1 both of the statements and figures of ,lang and of the facts to be described presently for medusae 7,margellium71 it is at least theoretically possible that both germinal and vegetative budding may occur in polyps as well as in medusae4 7b7 ,the ,medusa4--,the clearest instance of germinal budding is furnished by ,margellium 7,rathkea7 octopunctatum1 one of the ,margelidae4 ,the budding of this medusa has been worked out in detail by ,chun 7,,hydrozoa1 #a71 to whom the reader must be referred for the interesting laws of budding regulating the sequence and order of formation of the buds4 ,the buds of ,margellium are produced on the manubrium in each of the four interradii1 and they arise from the ectoderm1 that is to say1 the germinal epithelium1 which later gives rise to the gonads4 ,the buds do not appear simultaneously but successively on each of the four sides of the manubrium1 thus3 #a #c #d #b and secondary buds may be produced on the medusa-buds before the latter are set free as medusae4 ,each bud arises as a thickening of the epithelium1 which first forms two or three layers 7fig4 #dg1 ,a71 and becomes separated into a superficial layer1 future ectoderm1 surrounding a central mass1 future endoderm 7fig4 #dg1 ,b74 ,the ectodermal epithelium on the distal side of the bud becomes thickened1 grows inwards1 and forms a typical entocodon 7fig4 #cg1 ,d1 ,e1 ,f74 ,the remaining development of the bud is just as described above for the indirect method of medusa-budding 7fig4 #dg1 ,g1 ,h74 ,when the bud is nearly complete1 the body-wall of the parent immediately below it becomes perforated1 placing the coelenteric cavity of the parent in secondary communication with that of the bud 7,h71 doubtless for the better nutrition of the latter4 ,especially noteworthy in the germinal budding of ,margellium is the formation of the entocodon1 as in the vegetative budding of the indirect type4 #e4 ,sporogony4--,this method of reproduction has been described by ,e4 ,metchnikoff in ,cunina and allied genera4 ,in individuals either of the male or female sex1 germ-cells which are quite undifferentiated and neutral in character1 become amoeboid1 and wander into the endoderm4 ,they divide each into two sister-cells1 one of which--the spore--becomes enveloped by the other4 ,the spore-cell multiplies by division1 while the enveloping cell is nutrient and protective4 ,the spore cell gives rise to a spore-larva1 which is set free in the coelenteron and grows into a medusa4 ,whether sporogony occurs also in the polyp or not remains to be proved4 #f4 ,sexual ,reproduction and ,embryology4--,the ovum of ,hydromedusae is usually one of a large number of ogonia1 and grows at the expense of its sister-cells4 ,no regular follicle is formed1 but the ocyte absorbs nutriment from the remaining ogonia4 ,in ,hydra the ocyte is a large amoeboid cell1 which sends out pseudopodia amongst the ogonia and absorbs nutriment from them4 ,when the ocyte is full grown1 the residual ogonia die off and disintegrate4 ,illustration3 ,,fig4 #dg4--;,budding from the ,ectoderm 7germinal epithelium7 in ,margellium4 7,after ,c4 ,chun47 ,a1 ,the epithelium becomes two-layered4 ,b1 ,the lower layer forms a solid mass of cells1 which 7,c7 becomes a vesicle1 the future endoderm1 containing the coelenteric cavity 7coel71 while the outer layer furnishes the future ectoderm4 ,d1 ,e1 ,f1 a thickening of the ectoderm on the distal side of the bud forms an entocodon 7,gc74 ,g1,h1 ,formation of the medusae4 s4c1 ,sub-umbral cavity4 r4c1 ,radial canal4 st1 ,stomach1 which in ,h acquires a secondary communication with the digestive cavity of the mother4 cc1 ,circular canal4 v1 ,velum4 t1 ,tentacle4 ,the spermatogenesis and maturation and fertilization of the germ-cells present nothing out of the common and need not be described here4 ,these processes have been studied in detail by ,a4 ,brauer #b for ,hydra4 ,the general course of the development is described in the article ,,hydrozoa4 ,we may distinguish the following series of stages3 7#a7 ovum2 7#b7 cleavage1 leading to formation of a blastula2 7#c7 formation of an inner mass or parenchyma1 the future endoderm1 by immigration or delamination1 leading to the so-called parenchymula-stage2 7#d7 formation of an archenteric cavity1 the future coelenteron1 by a splitting of the internal parenchyma1 and of a blastopore1 the future mouth1 by perforation at one pole1 leading to the gastrula-stage2 7#e7 the outgrowth of tentacles round the mouth 7blastopore71 leading to the actinula-stage2 and 7#f7 the actinula becomes the polyp or medusa in the manner described elsewhere 7see articles ,,hydrozoa1 ,,polyp and ,,medusa74 ,this is the full1 ideal development1 which is always contracted or shortened to a greater or less extent4 ,if the embryo is set free as a free-swimming1 so-called planula-larva1 in the blastula1 parenchymula1 or gastrula stage1 then a free actinula stage is not found2 if1 on the other hand1 a free actinula occurs1 then there is no free planula stage4 ,the cleavage of the ovum follows two types1 both seen in ,tubularia 7,brauer #c74 ,in the first1 a cleavage follows each nuclear division2 in the second1 the nuclei multiply by division a number of times1 and then the ovum divides into as many blastomeres as there are nuclei present4 ,the result of cleavage in all cases is a typical blastula1 which when set free becomes oval and develops a flagellum to each cell1 but when not set free1 it remains spherical in form and has no flagella4 ,the germ-layer formation is always by immigration or delamination1 never by invagination4 ,when the blastula is oval and free-swimming the inner mass is formed by unipolar immigration from the hinder pole4 ,when the blastula is spherical and not set free1 the germ-layer formation is always multipolar1 either by immigration or by delamination1 i4e4 by tangential division of the cells of the blastoderm1 as in ,geryonia1 or by a mixture of immigration and delamination1 as in ,hydra1 ,tubularia1 c4 ,the blastopore is formed as a secondary perforation at one spot1 in free-swimming forms at the hinder pole4 ,formation of archenteron and blastopore may1 however1 be deferred till a later stage 7actinula or after74 ,the actinula stage is usually suppressed or not set free1 but it is seen in ,tubularia 7fig4 #dh71 where it is ambulatory1 in ,gonionemus 7,trachomedusae71 and in ,cunina 7,narcomedusae71 where it is parasitic4 ,illustration3 ,modified from a plate by ,l4 ,agassiz1 ,contributions to ,nat4 ,hist4 ,u4,s41 iv4 ,,fig4 #dh4--;,free ,actinula of ,tubularia4 ,in ,leptolinae the embryonic development culminates in a polyp1 which is usually formed by fixation of a planula 7parenchymula71 rarely by fixation of an actinula4 ,the planula may fix itself 7#a7 by one end1 and then becomes the hydrocaulus and hydranth1 while the hydrorhiza grows out from the base2 or 7#b7 partly by one side and then gives rise to the hydrorhiza as well as to the other parts of the polyp2 or 7#c7 entirely by its side1 and then forms a recumbent hydrorhiza from which a polyp appears to be budded as an upgrowth4 ,in ,trachylinae the development produces always a medusa1 and there is no polyp-stage4 ,the medusa arises direct from the actinula-stage and there is no entocodon formed1 as in the budding described above4 ,life-cycles of the ,hydromedusae4--,the life-cycle of the ,leptolinae consists of an alternation of generations in which non-sexual individuals1 polyps1 produce by budding sexual individuals1 medusae1 which give rise by the sexual process to the non-sexual polyps again1 so completing the cycle4 ,hence the alternation is of the type termed metagenesis4 ,the ,leptolinae are chiefly forms belonging to the inshore fauna4 ,the ,trachylinae1 on the other hand1 are above all oceanic forms1 and have no polyp-stage1 and hence there is typically no alternation in their life-cycle4 ,it is commonly assumed that the ,trachylinae are forms which have lost the alternation of generations possessed by them ancestrally1 through secondary simplification of the life-cycle4 ,hence the ,trachylinae are termed hypogenetic medusae to contrast them with the metagenetic ,leptolinae4 ,the whole question has1 however1 been argued at length by ,w4 ,k4 ,brooks #d1 who adduces strong evidence for a contrary view1 that is to say1 for regarding the direct type of development seen in ,trachylinae as more primitive1 and the metagenesis seen in ,leptolinae as a secondary complication introduced into the life-cycle by the acquisition of larval budding4 ,the polyp is regarded1 on this view1 as a form phylogenetically older than the medusa1 in short1 as nothing more than a sessile actinula4 ,in ,trachylinae the polyp-stage is passed over1 and is represented only by the actinula as a transitory embryonic stage4 ,in ,leptolinae the actinula becomes the sessile polyp which has acquired the power of budding and producing individuals either of its own or of a higher rank2 it represents a persistent larval stage and remains in a sexually immature condition as a neutral individual1 sex being an attribute only of the final stage in the development1 namely the medusa4 ,the polyp of the ,leptolinae has reached the limit of its individual development and is incapable of becoming itself a medusa1 but only produces medusa-buds2 hence a true alternation of generations is produced4 ,in ,trachylinae also the beginnings of a similar metagenesis can be found4 ,thus in ,cunina octonaria1 the ovum develops into an actinula which buds daughter-actinulae2 all of them1 both parent and offspring1 develop into medusae1 so that there is no alternation of generations1 but only larval multiplication4 ,in ,cunina parasitica1 however1 the ovum develops into an actinula1 which buds actinulae as before1 but only the daughter-actinulae develop into medusae1 while the original1 parent-actinula dies off2 here1 therefore1 larval budding has led to a true alternation of generations4 ,in ,gonionemus the actinula becomes fixed and polyp-like1 and reproduces by budding1 so that here also an alternation of generations may occur4 ,in the ,leptolinae we must first substitute polyp for actinula1 and then a condition is found which can be compared to the case of ,cunina parasitica or ,gonionemus1 if we suppose that neither the parent-actinula 7i4e4 founder-polyp7 nor its offspring by budding 7polyps of the colony7 have the power of becoming medusae1 but only of producing medusae by budding4 ,for further arguments and illustrations the reader must be referred to ,brooks's most interesting memoir4 ,the whole theory is one most intimately connected with the question of the relation between polyp and medusa1 to be discussed presently4 ,it will be seen elsewhere1 however1 that whatever view may be held as to the origin of metagenesis in ,hydromedusae1 in the case of ,scyphomedusae 7q4v47 no other view is possible than that the alternation of generations is the direct result of larval proliferation4 ,to complete our survey of life-cycles in the ,hydromedusae it is necessary to add a few words about the position of ,hydra and its allies4 ,if we accept the view that ,hydra is a true sexual polyp1 and that its gonads are not gonophores 7i4e4 medusa-buds7 in the extreme of degeneration1 then it follows from ,brooks's theory that ,hydra must be descended from an archaic form in which the medusan type of organization had not yet been evolved4 ,hydra must1 in short1 be a living representative of the ancestor of which the actinula-stage is a transient reminiscence in the development of higher forms4 ,it may be pointed out in this connexion that the fixation of ,hydra is only temporary1 and that the animal is able at all times to detach itself1 to move to a new situation1 and to fix itself again4 ,there is no difficulty whatever in regarding ,hydra as bearing the same relation to the actinula-stage of other ,hydromedusae that a ,rotifer bears to a trochophore-larva or a fish to a tadpole4 ,the ,relation of ,polyp and ,medusa4--,many views have been put forward as to the morphological relationship between the two types of person in the ,hydromedusae4 ,for the most part1 polyp and medusa have been regarded as modifications of a common type1 a view supported by the existence1 among ,scyphomedusae 7q4v471 of sessile polyp-like medusae 7,lucernaria1 c474 ,r4 ,leuckart in #ahdh compared medusae in general terms to flattened polyps4 ,g4 ,j4 ,allman #a put forward a more detailed view1 which was as follows4 ,in some polyps the tentacles are webbed at the base1 and it was supposed that a medusa was a polyp of this kind set free1 the umbrella being a greatly developed web or membrane extending between the tentacles4 ,a very different theory was enunciated by ,e4 ,metchnikoff4 ,in some hydroids the founder-polyp1 developed from a planula after fixation1 throws out numerous outgrowths from the base to form the hydrorhiza2 these outgrowths may be radially arranged so as to form by contact or coalescence a flat plate4 ,mechnikov considered the plate thus formed at the base of the polyp as equivalent to the umbrella1 and the body of the polyp as equivalent to the manubrium1 of the medusa2 on this view the marginal tentacles almost invariably present in medusae are new formations1 and the tentacles of the polyp are represented in the medusa by the oral arms which may occur round the mouth1 and which sometimes1 e4g4 in ,margelidae1 have the appearance and structure of tentacles4 ,apart from the weighty arguments which the development furnishes against the theories of ,allman and ,mechnikov1 it may be pointed out that neither hypothesis gives a satisfactory explanation of a structure universally present in medusae of whatever class1 namely the endoderm-lamella1 discovered by the brothers ,o4 and ,r4 ,hertwig4 ,it would be necessary to regard this structure as a secondary extension of the endoderm in the tentacle-web1 on ,allman's theory1 or between the outgrowths of the hydrorhiza1 on ,mechnikov's hypothesis4 ,the development1 on the contrary1 shows unequivocally that the endoderm-lamella arises as a local coalescence of the endodermal linings of a primitively extensive gastral space4 ,the question is one intimately connected with the view taken as to the nature and individuality of polyp1 medusa and gonophore respectively4 ,on this point the following theories have been put forward4 #a4 ,the theory that the medusa is simply an organ1 which has become detached and has acquired a certain degree of independence1 like the well-known instance of the hectocotyle of the cuttle-fish4 ,on this view1 put forward by ,e4 van ,beneden and ,t4 ,h4 ,huxley1 the sporosac is the starting-point of an evolution leading up through the various types of gonophores to the free medusa as the culminating point of a phyletic series4 ,the evidence against this view may be classed under two heads3 first1 comparative evidence2 hydroids very different in their structural characters and widely separate in the systematic classification of these organisms may produce medusae very similar1 at least so far as the essential features of medusan organization are concerned2 on the other hydroids closely allied1 perhaps almost indistinguishable1 may produce gonophores in the one case1 medusae in the other2 for example1 ,hydractinia 7gonophores7 and ,podocoryne 7medusae71 ,tubularia 7gonophores7 and ,ectopleura 7medusae71 ,coryne 7gonophores7 and ,syncoryne 7medusae71 and so on4 ,if it is assumed that all these genera bore gonophores ancestrally1 then medusa of similar type must have been evolved quite independently in a great number of cases4 ,secondly1 there is the evidence from the development1 namely1 the presence of the entocodon in the medusa-bud1 a structure which1 as explained above1 can only be accounted for satisfactorily by derivation from a medusan type of organization4 ,hence it may be concluded that the gonophores are degenerate medusae1 and not that the medusae are highly elaborated gonophores1 as the organ-theory requires4 #b4 ,the theory that the medusa is an independent individual1 fully equivalent to the polyp in this respect1 is now universally accepted as being supported by all the facts of comparative morphology and development4 ,the question still remains open1 however1 which of the two types of person may be regarded as the most primitive1 the most ancient in the race-history of the ,hydromedusae4 ,f4 ,m4 ,balfour put forward the view that the polyp was the more primitive type1 and that the medusa is a special modification of the polyp for reproductive purposes1 the result of division of labour in a polyp-colony1 whereby special reproductive persons become detached and acquire organs of locomotion for spreading the species4 ,w4 ,k4 ,brooks1 on the other hand1 as stated above1 regards the medusa as the older type and looks upon both polyp and medusa1 in the ,hydromedusae1 as derived from a free-swimming or floating actinula1 the polyp being thus merely a fixed nutritive stage1 possessing secondarily acquired powers of multiplication by budding4 ,the ,hertwigs when they discovered the endoderm-lamella showed on morphological grounds that polyp and medusa are independent types1 each produced by modification in different directions of a more primitive type represented in development by the actinula-stage4 ,if a polyp1 such as ,hydra1 be regarded simply as a sessile actinula1 we must certainly consider the polyp to be the older type1 and it may be pointed out that in the ,anthozoa only polyp-individuals occur4 ,this must not be taken to mean1 however1 that the medusa is derived from a sessile polyp2 it must be regarded as a direct modification of the more ancient free actinula form1 without primitively any intervening polyp-stage1 such as has been introduced secondarily into the development of the ,leptolinae and represents a revival1 so to speak1 of an ancestral form or larval stage1 which has taken on a special role in the economy of the species4 ,,systematic ,,review ,,of ,,the ,,hydromedusae ,,order ,i4 ,eleutheroblastea4--,simple polyps which become sexually mature and which also reproduce non-sexually1 but without any medusoid stage in the life-cycle4 ,the sub-order includes the family ,hydridae1 containing the common fresh-water polyps of the genus ,hydra4 ,certain other forms of doubtful affinities have also been referred provisionally to this section4 ,hydra4--,this genus comprises fresh-water polyps of simple structure4 ,the body bears tentacles1 but shows no division into hydrorhiza1 hydrocaulus or hydranth2 it is temporarily fixed and has no perisarc4 ,the polyp is usually hermaphrodite1 developing both ovaries and testes in the same individual4 ,there is no free-swimming planula larva1 but the stage corresponding to it is passed over in an enveloping cyst1 which is secreted round the embryo by its own ectodermal layer1 shortly after the germ-layer formation is complete1 i4e4 in the parenchymula-stage4 ,the envelope is double1 consisting of an external chitinous stratified shell1 and an internal thin elastic membrane4 ,protected by the double envelope1 the embryo is set free as a so-called egg1 and in ,europe it passes the winter in this condition4 ,in the spring the embryo bursts its shell and is set free as a minute actinula which becomes a ,hydra4 ,many species are known1 of which three are common in ,european waters4 ,it has been shown by ,c4 ,f4 ,jickeli 7#bh7 that the species are distinguishable by the characters of their nematocysts4 ,they also show characteristic differences in the egg 7,brauer #b74 ,in ,hydra viridis the polyp is of a green colour and produces a spherical egg with a smooth shell which is dropped into the mud4 ,h4 grisea is greyish in tint and produces a spherical egg with a spiky shell1 which also is dropped into the mud4 ,h4 fusca 7 ,h4 vulgaris7 is brown in colour1 and produces a bun-shaped egg1 spiky on the convex surface1 and attached to a water-weed or some object by its flattened side4 ,brauer found a fourth species1 similar in appearance to ,h4 fusca1 but differing from the three other species in being of separate sexes1 and in producing a spherical egg with a knobby shell1 which is attached like that of ,h4 fusca4 ,the fact already noted that the species of ,hydra can be distinguished by the characters of their nematocysts is a point of great interest4 ,in each species1 two or three kinds of nematocysts occur1 some large1 some small1 and for specific identification the nematocysts must be studied collectively in each species4 ,it is very remarkable that this method of characterizing and diagnozing species has never been extended to the marine hydroids4 ,it is quite possible that the characters of the nematocysts might afford data as useful to the systematist in this group as do the spicules of sponges1 for instance4 ,it would be particularly interesting to ascertain how the nematocysts of a polyp are related to those possessed by the medusa budded from it1 and it is possible that in this manner obscure questions of relationship might be cleared up4 ,protohydra is a marine genus characterized by the absence of tentacles1 by a great similarity to ,hydra in histological structure1 and by reproduction by transverse fission4 ,it was found originally in an oyster-farm at ,ostend4 ,the sexual reproduction is unknown4 ,for further information see ,c4 ,chun 7,,hydrozoa #a4 ,pl4 ,i474 ,illustration3 ,,fig4 #di4--;,diagram showing possible modifications of persons of a gymnoblastic ,hydromedusa4 7,after ,allman47 a1 ,hydrocaulus 7stem74 b1 ,hydrorhiza 7root74 c1 ,enteric cavity4 d1 ,endoderm4 e1 ,ectoderm4 f1 ,perisarc1 7horny case74 g1 ,hydranth 7hydriform person7 expanded4 g'1 ,hydranth 7hydriform person7 contracted4 h1 ,hypostome1 bearing mouth at its extremity4 k1 ,sporosac springing from the hydrocaulus4 k'1 ,sporosac springing from m1 a modified hydriform person 7blastostyle73 the genitalia are seen surrounding the spadix or manubrium4 l1 ,medusiform person or medusa4 m1 ,blastostyle4 ,polypodium hydriforme ,ussow is a fresh-water form parasitic on the eggs of the sterlet4 ,a stolon of unknown origin produces thirty-two buds1 which become as many ,polypodia2 each has twenty-four tentacles and divides by fission repeated twice into four individuals1 each with six tentacles4 ,the daughter-individuals grow1 form the full number of twenty-four tentacles and divide again4 ,the polyps are free and walk on their tentacles4 ,see ,ussow #ed4 ,tetraplatia volitans ,viguier is a remarkable floating marine form4 ,see ,c4 ,viguier #ef and ,delage and ,hrouard 7,hydrozoa #b74 ,haleremita ,schaudinn4 ,see ,f4 ,schaudinn #ej and ,delage and ,hrouard 7,,hydrozoa #b74 ,in all the above-mentioned genera1 with the exception of ,hydra1 the life-cycle is so imperfectly known that their true position cannot be determined in the present state of our knowledge4 ,they may prove eventually to belong to other orders4 ,hence only the genus ,hydra can be considered as truly representing the order ,eleutheroblastea4 ,the phylogenetic position of this genus has been discussed above4 ,,order ,,ii4 ,hydroidea seu ,leptolinae4--,hydromedusae with alternation of generations 7metagenesis7 in which a non-sexual polyp-generation 7trophosome7 produces by budding a sexual medusa-generation 7gonosome74 ,the polyp may be solitary1 but more usually produces polyps by budding and forms a polyp-colony4 ,the polyp usually has the body distinctly divisible into hydranth1 hydrocaulus and hydrorhiza1 and is usually clothed in a perisarc4 ,the medusae may be set free or may remain attached to the polyp-colony and degenerate into a gonophore4 ,when fully developed the medusa is characterized by the sense organs being composed entirely of ectoderm1 developed independently of the tentacles1 and innervated from the sub-umbral nerve-ring4 ,the two kinds of persons present in the typical ,hydroidea make the classification of the group extremely difficult1 for reasons explained above4 ,hence the systematic arrangement that follows must be considered purely provisional4 ,a natural classification of the ,hydroidea has yet to be put forward4 ,many genera and families are separated by purely artificial characters1 mere shelf-and-bottle groupings devised1 for the convenience of the museum curator and the collector4 ,thus many subdivisions are diagnosed by setting free medusae in one case1 or producing gonophores in another1 although it is very obvious1 as pointed out above1 that a genus producing medusae may be far more closely allied to one producing gonophores than to another producing medusae1 or vice versa1 and that in some cases the production of medusae or gonophores varies with the season or the sex4 ,moreover1 ,p4 ,hallez #bb has recently shown that hydroids hitherto regarded as distinct species are only forms of the same species grown under different conditions4 ,,sub-,,order #a4 ,,hydroidea ,,gymnoblastea 7,,anthomedusae74--,trophosome without hydrothecae or gonothecae1 with monopodial type of budding4 ,gonosome with free medusae or gonophores2 medusae usually with ocelli1 never with otocysts4 ,the gymnoblastic polyp usually has a distinct perisarc investing the hydrorhiza and the hydrocaulus1 sometimes also the hydranth as far as the bases of the tentacles 7,bimeria72 but in such cases the perisarc forms a closely-fitting investment or cuticule on the hydranth1 never a hydrotheca standing off from it1 as in the next sub-order4 ,the polyps may be solitary1 or form colonies1 which may be of the spreading or encrusting type1 or arborescent1 and then always of monopodial growth and budding4 ,in some cases1 any polyp of the colony may bud medusae2 in other cases1 only certain polyps1 the blastostyles1 have this power4 ,when blastostyles are present1 however1 they are never enclosed in special gonothecae as in the next sub-order4 ,in this sub-order the characters of the hydranth are very variable1 probably owing to the fact that it is exposed and not protected by a hydrotheca1 as in ,calyptoblastea4 ,illustration3 ,,fig4 #ej4--,sarsia 7,dipurena7 gemnifera4 b1 ,the long manubrium1 bearing medusiform buds2 a1 mouth4 ,illustration3 ,,fig4 #ea4--,sarsia prolifera4 ,ocelli are seen at the base of the tentacles1 and also 7as an exception7 groups of medusiform buds4 ,speaking generally1 three principal types of hydranth can be distinguished1 each with subordinate varieties of form4 #a4 ,club-shaped hydranths with numerous tentacles1 generally scattered irregularly1 sometimes with a spiral arrangement1 or in whorls 7verticillate74 7a7 ,tentacles filiform2 type of ,clava 7fig4 #e71 ,cordylophora1 c4 7b7 ,tentacles capitate1 simple2 type of ,coryne and ,syncoryne2 ,myriothela is an aberrant form with some of the tentacles modified as claspers to hold the ova4 7c7 ,tentacles capitate1 branched1 wholly or in part2 type of ,cladocoryne4 7d7 ,tentacles filiform or capitate1 tending to be arranged in definite whorls2 type of ,stauridium 7fig4 #b71 ,cladonema and ,pennaria4 #b4 ,hydranth more shortened1 daisy-like in form1 with two whorls of tentacles1 oral and aboral4 7a7 ,tentacles filiform1 simple1 radially arranged or scattered irregularly2 type of ,tubularia 7fig4 #d71 ,corymorpha 7fig4 #c71 ,nemopsis1 ,pelagohydra1 c4 7b7 ,tentacles with a bilateral arrangement1 branched tentacles in addition to simple filiform ones2 type of ,branchiocerianthus4 #c4 ,hydranth with a single circlet of tentacles4 7a7 ,with filiform tentacles2 the commonest type1 seen in ,bougainvillea 7fig4 #ac71 ,eudendrium1 c4 7b7 ,with capitate tentacles2 type of ,clavatella4 #d4 ,hydranth with tentacles reduced below four2 type of ,lar 7fig4 #aa71 ,monobrachium1 c4 ,the ,anthomedusa in form is generally deep1 bell-shaped4 ,the sense organs are typically ocelli1 never otocysts4 ,the gonads are borne on the manubrium1 either forming a continuous ring 7,codonid type71 or four masses or pairs of masses 7,oceanid type74 ,the tentacles may be scattered singly round the margin of the umbrella 7monerenematous7 or arranged in tufts 7lophonematous72 in form they may be simple or branched 7,cladonemid type72 in structure they may be hollow 7coelomerinthous72 or solid 7pycnomerinthous74 ,when sessile gonophores are produced1 they may show all stages of degeneration4 ,classification4--,until quite recently the hydroids 7,gymnoblastea7 and the medusae 7,anthomedusae7 have been classified separately1 since the connexion between them was insufficiently known4 ,delage and ,hrouard 7,,hydrozoa #b7 were the first to make an heroic attempt to unite the two classifications into one1 to which ,hickson 7,,hydrozoa #d7 has made some additions and slight modifications4 ,the classification given here is for the most part that of ,delage and ,hrouard4 ,it is certain1 however1 that no such classification can be considered final at present1 but must undergo continual revision in the future4 ,with this reservation we may recognize fifteen well-characterized families and others of more doubtful nature4 ,certain discrepancies must also be noted4 #a4 ,margelidae 7 medusa-family ,margelidae hydroid families ,bougainvillidae1 ,dicorynidae1 ,bimeridae and ,eudendridae74 ,trophosome arborescent1 with hydranths of ,bougainvillea-type2 gonosome free medusae or gonophores1 the medusae with solid tentacles in tufts 7lophonematous74 ,common genera are the hydroid ,bougainvillea 7figs4 #ab1 #ac71 and the medusae ,hippocrene 7budded from ,bougainvillea71 ,margelis1 ,rathkea 7fig4 #bd71 and ,margellium4 ,other hydroids are ,garveia1 ,bimeria1 ,eudendrium and ,heterocordyle1 with gonophores1 and ,dicoryne with peculiar sporosacs4 ,illustration3 ,after ,haeckel1 ,system der ,medusen1 by permission of ,gustav ,fischer4 ,,fig4 #eb4--,tiara pileata1 ,l4 ,agassiz4 #b4 ,podocorynidae 7 medusa-families ,thamnostomidae and ,cytaeidae hydroid families ,podocorynidae and ,hydractiniidae74 ,trophosome encrusting with hydranths of ,bougainvillea-type1 polyps differentiated into blastostyles1 gastrozoids and dactylozoids2 gonosome free medusae or gonophores4 ,the typical genus is the well-known hydroid ,podocoryne1 budding the medusa known as ,dysmorphosa2 ,thamnostylus1 ,cytaeis1 c41 are other medusae with unknown hydroids4 ,hydractinia 7figs4 #i1 #aj7 is a familiar hydroid genus1 bearing gonophores4 #c4 ,cladonemidae4--,trophosome1 polyps with two whorls of tentacles1 the lower filiform1 the upper capitate2 gonosome1 free medusae1 with tentacles solid and branched4 ,the type-genus ,cladonema 7fig4 #bj7 is a common ,british form4 #d4 ,clavatellidae4--,trophosome1 polyps with a single whorl of capitate tentacles2 gonosome1 free medusae1 with tentacles branched1 solid4 ,clavatella 7fig4 #ba71 with a peculiar ambulatory medusa is a ,british form4 #e4 ,pennariidae4--,trophosome1 polyps with an upper circlet of numerous capitate tentacles1 and a lower circlet of filiform tentacles4 ,pennaria1 with a free medusa known as ,globiceps1 is a common ,mediterranean form4 ,stauridium 7fig4 #b7 is a ,british hydroid4 #f4 ,tubulariidae4--,trophosome1 polyps with two whorls of tentacles1 both filiform4 ,tubularia 7fig4 #d71 a well-known ,british hydroid1 bears gonophores4 #g4 ,corymorphidae 7including the medusa-family ,hybocodonidae74--,trophosome solitary polyps1 with two whorls of tentacles2 gonosome1 free medusae or gonophores4 ,corymorpha 7fig4 #c71 a well-known ,british genus1 sets free a medusa known as ,steenstrupia 7fig4 #bb74 ,here belong the deep-sea genera ,monocaulus and ,branchiocerianthus1 including the largest hydroid polyps known1 both genera producing sessile gonophores4 ,illustration3 ,after ,haeckel1 ,system der ,medusen1 by permission of ,gustav ,fischer4 ,,fig4 #ec4--,pteronema darwinii4 ,the apex of the stomach is prolonged into a brood pouch containing embryos4 #h4 ,dendroclavidae4--,trophosome1 polyp with filiform tentacles in three or four whorls4 ,dendroclava1 a hydroid1 produces the medusa known as ,turritopsis4 #i4 ,clavidae 7including the medusa-family ,tiaridae 7figs4 #bg and #ea74 ,trophosome1 polyps with scattered filiform tentacles2 gonosome1 medusae or gonophores1 the medusae with hollow tentacles4 ,clava 7fig4 #e71 a common ,british hydroid1 produces gonophores2 so also does ,cordylophora1 a form inhabiting fresh or brackish water4 ,turris produces free medusae4 ,amphinema is a medusan genus of unknown hydroid4 #aj4 ,bythotiaridae4--,trophosome unknown2 gonosome1 free medusae1 with deep1 bell-shaped umbrella1 with interradial gonads on the base of the stomach1 with branched radial canals1 and correspondingly numerous hollow tentacles4 ,bythotiara1 ,sibogita4 #aa4 ,corynidae 7 hydroid families ,corynidae1 ,syncorynidae and ,cladocorynidae medusan family ,sarsiidae74--,trophosome polyps with capitate tentacles1 simple or branched1 scattered or verticillate2 gonosome1 free medusae or gonophores4 ,coryne1 a common ,british hydroid1 produces gonophores2 ,syncoryne1 indistinguishable from it1 produces medusae known as ,sarsia 7fig4 #ea74 ,cladocoryne is another hydroid genus2 ,codonium and ,dipurena 7fig4 #ej7 are medusan genera4 #ab4 ,myriothelidae4--,the genus ,myriothela is a solitary polyp with scattered capitate tentacles1 producing sporosacs4 #ac4 ,hydrolaridae4--,trophosome 7only known in one genus71 polyps with two tentacles forming a creeping colony2 gonosome1 free medusae with four1 six or more radial canals1 giving off one or more lateral branches which run to the margin of the umbrella1 with the stomach produced into four1 six or more lobes1 upon which the gonads are developed2 the mouth with four lips or with a folded margin2 the tentacles simple1 arranged evenly round the margin of the umbrella4 ,the remarkable hydroid ,lar 7fig4 #aa7 grows upon the tubes of the worm ,sabella and produces a medusa known as ,willia4 ,another medusan genus is ,proboscidactyla4 #ad4 ,monobrachiidae4--,the genus ,monobrachium is a colony-forming hydroid which grows upon the shells of bivalve molluscs1 each polyp having but a single tentacle4 ,it buds medusae1 which1 however1 are as yet only known in an immature condition 7,c4 ,mereschkowsky #da74 #ae4 ,ceratellidae4--,trophosome polyps forming branching colonies of which the stem and main branches are thick and composed of a network of anastomosing coenosarcal tubes covered by a common ectoderm and supported by a thick chitinous perisarc2 hydranths similar to those of ,coryne2 gonosome1 sessile gonophores4 ,ceratella1 an exotic genus from the coast of ,east ,africa1 ,new ,south ,wales and ,japan4 ,the genera ,dehitella ,gray and ,dendrocoryne ,inaba should perhaps be referred to this family2 the last-named is regarded by ,s4 ,goto #af as the type of a distinct family1 ,dendrocorynidae4 ,doubtful families1 or forms difficult to classify1 are3 ,pteronemidae1 ,medusae of ,cladonemid type1 with hydroids for the most part unknown4 ,the ,british genus ,gemmaria1 however1 is budded from a hydroid referable to the family ,corynidae4 ,pteronema 7fig4 #ec74 ,nemopsidae1 for the floating polyp ,nemopsis1 very similar to ,tubularia in character2 the medusa1 on the other hand1 is very similar to ,hippocrene 7,margelidae74 ,see ,c4 ,chun 7,,hydrozoa #a74 ,pelagohydridae1 for the floating polyp ,pelagohydra1 ,dendy1 from ,new ,zealand4 ,the animal is a solitary polyp bearing a great number of medusa-buds4 ,the body1 representing the hydranth of an ordinary hydroid1 has the aboral portion modified into a float1 from which hangs down a proboscis bearing the mouth4 ,the float is covered with long tentacles and bears the medusa-buds4 ,the proboscis bears at its extremity a circlet of smaller oral tentacles4 ,thus the affinities of the hydranth are clearly1 as ,dendy points out1 with a form such as ,corymorpha1 which also is not fixed but only rooted in the mud4 ,the medusae1 on the other hand1 have the tentacles in four tufts of 7in the buds7 five each1 and thus resemble the medusae of the family ,margelidae4 ,see ,a4 ,dendy #ab4 ,illustration3 ,fig4 #ed4--;,diagram showing possible modifications of the persons of a ,calyptoblastic ,hydromedusa4 ,letters a to h same as in fig4 #di4 i1 ,the horny cup or hydrotheca of the hydriform persons2 l1 medusiform person springing from m1 a modified1 hydriform person 7blastostyle72 n1 the horny case or gonangium enclosing the blastostyle and its buds4 ,this and the hydrotheca i give origin to the name ,calyptoblastea4 7,after ,allman47 ,perigonimus4--,this common ,british hydroid belongs by its characters to the family ,bougainvillidae2 it produces1 however1 a medusa of the genus ,tiara 7fig4 #eb71 referable to the family ,clavidae2 a fact sufficient to indicate the tentative character of even the most modern classifications of this order4 ,,sub-,,order ,,ii4 ,,hydroidea ,,calyptoblastea 7,,leptomedusae74--,trophosome with polyps always differentiated into nutritive and reproductive individuals 7blastostyles7 enclosed in hydrothecae and gonothecae respectively2 with sympodial type of budding4 ,gonosome with free medusae or gonophores2 the medusae typically with otocysts1 sometimes with cordyli or ocelli 7figs4 #ed1 #ee74 ,illustration3 ,,fig4 #ee4--,view of the ,oral ,surface of one of the ,leptomedusae 7,irene pellucida1 ,haeckel71 to show the numerous tentacles and the otocysts4 ge1 ,genital glands4 ,m1 ,manubrium4 ot1 ,otocysts4 rc1 ,the four radiating canals4 ,ve1 ,the velum4 ,the calyptoblastic polyp of the nutritive type is very uniform in character1 its tendency to variation being limited1 as it were1 by the enclosing hydrotheca4 ,the hydranth almost always has a single circlet of tentacles1 like the ,bougainvillea-type1 in the preceding sub-order2 an exception is the curious genus ,clathrozoon1 in which the hydranth has a single tentacle4 ,the characteristic hydrotheca is formed by the bud at an early stage 7fig4 #ef72 when complete it is an open cup1 in which the hydranth develops and can be protruded from the opening for the capture of food1 or is withdrawn into it for protection4 ,solitary polyps are unknown in this sub-order2 the colony may be creeping or arborescent in form2 if the latter1 the budding of the polyps1 as already stated1 is of the sympodial type1 and either biserial1 forming stems capable of further branching1 or uniserial1 forming pinnules not capable of further branching4 ,in the biserial type the polyps on the two sides of the stem have primitively an alternating1 zigzag arrangement2 but1 by a process of differential growth1 quickened in the #ast1 #crd1 #eth1 c41 members of the stem1 and retarded in the #bnd1 #dth1 #fth1 c41 members1 the polyps may assume secondarily positions opposite to one another on the two sides of the stem4 ,other variations in the mode of growth or budding bring about further differences in the building up of the colony1 which are not in all cases properly understood and cannot be described in detail here4 ,the stem may contain a single coenosarcal tube 7monosiphonic7 or several united in a common perisarc 7polysiphonic74 ,an important variation is seen1 in the form of the hydrotheca itself1 which may come off from the main stem by a stalk1 as in ,obelia1 or may be sessile1 without a stalk1 as in ,sertularia4 ,illustration3 ,after ,allman1 ,gymnoblastic ,hydroids1 by permission of the council of the ,ray ,society4 ,,fig4 #ef4--;,diagrams to show the mode of formation of the ,hydrotheca and ,gonotheca in ,calyptoblastic ,hydroids4 ,a-,d are stages common to both2 from ,d arises the hydrotheca 7,e7 or the gonotheca 7,f72 th1 theca2 st1 stomach2 t1 tentacles2 m1 mouth2 mb1 medusa-buds4 ,in many ,calyptoblastea there occur also reduced defensive polyps or dactylozoids1 which in this sub-order have received the special name of sarcostyles4 ,such are the snake-like zoids of ,ophiodes and other genera1 and as such are generally interpreted the machopolyps of the ,plumularidea4 ,these organs are supported by cuplike structures of the perisarc1 termed nematophores1 regarded as modified hydrothecae supporting the specialized polyp-individuals4 ,they are specially characteristic of the family ,plumularidae4 ,the medusa-buds1 as already stated1 are always produced from blastostyles1 reduced non-nutritive polyps without mouth or tentacles4 ,an apparent1 but not real1 exception is ,halecium halecinum1 in which the blastostyle is produced from the side of a nutritive polyp1 and both are enclosed in a common theca without a partition between them 7,allman #a p4 #ej1 fig4 #bd74 ,the gonotheca is formed in its early stage in the same way as the hydrotheca1 but the remains of the hydranth persists as an operculum closing the capsule1 to be withdrawn when the medusae or genital products are set free 7fig4 #ef74 ,the blastostyles1 gonophores and gonothecae furnish a series of variations which can best be considered as so many stages of evolution4 ,stage #a1 seen in ,obelia4 ,numerous medusae are budded successively within the gonotheca and set free2 they swim off and mature in the open sea 7,allman #a1 p4 #dh1 figs4 #ah1 #ai74 ,stage #b1 seen in ,gonothyraea4 ,medusae1 so-called meconidia1 are budded but not liberated2 each in turn1 when it reaches sexual maturity1 is protruded from the gonotheca by elongation of the stalk1 and sets free the embryos1 after which it withers and is replaced by another 7,allman #a1 p4 #eg1 fig4 #bh74 ,stage #c1 seen in ,sertularia4--,the gonophores are reduced in varying degree1 it may be to sporosacs2 they are budded successively from the blastostyle1 and each in turn1 when ripe1 protrudes the spadix through the gonotheca 7fig4 #eg1 ,a1 ,b74 ,the spadix forms a gelatinous cyst1 the so-called acrocyst 7ac71 external to the gonotheca 7gth71 enclosing and protecting the embryos4 ,then the spadix withers1 leaving the embryos in the acrocyst1 which may be further protected by a so-called marsupium1 a structure formed by tentacle-like processes growing out from the blastostyle to enclose the acrocyst1 each such process being covered by perisarc like a glove-finger secreted by it 7fig4 #eg1 ,c74 7,allman #a1 pp4 #ej1 #ea1 figs4 #ba-bd2 ,weismann #eh1 p4 #agj1 pl4 ix41 figs4 #g1 #h47 ,stage #d1 seen in ,plumularidae4--,the generative elements are produced in structures termed corbulae1 formed by reduction and modification of branches of the colony4 ,each corbula contains a central row of blastostyles enclosed and protected by lateral rows of branches representing stunted buds 7,allman #a1 p4 #ff1 fig4 #cj74 ,illustration3 ,after ,allman1 ,gymnoblastic ,hydroids1 by permission of the council of the ,ray ,society4 ,fig4 #eg4--;,diagrams to show the mode of formation of an ,acrocyst and a ,marsupium4 ,in ,a two medusa-buds are seen within the gonotheca 7gth71 the upper more advanced than the lower one4 ,in ,b the spadix of the upper bud has protruded itself through the top of the gonotheca and the acrocyst 7ac7 is secreted round it4 ,in ,c the marsupium 7m7 is formed as finger-like process from the summit of the blastostyle1 enclosing the acrocyst2 b1 medusa-buds on the blastostyle4 ,the ,leptomedusa in form is generally shallow1 more or less saucer-like1 with velum less developed than in ,anthomedusae 7fig4 #ee74 ,the characteristic sense-organs are ectodermal otocysts1 absent1 however1 in some genera1 in which case cordyli may replace them4 ,when otocysts are present1 they are at least eight in number1 situated adradially1 but are often very numerous4 ,the cordyli are scattered on the ring-canal4 ,ocelli1 if present1 are borne on the tentacle-bulbs4 ,the tentacles are usually hollow1 rarely solid 7,obelia74 ,in number they are rarely less than four1 but in ,dissonema there are only two4 ,primitively there are four perradial tentacles1 to which may be added four interradial1 or they may become very numerous and are then scattered evenly round the margin1 never arranged in tufts or clusters4 ,in addition to tentacles1 there may be marginal cirri 7,laodice7 with a solid endodermal axis1 spirally coiled1 very contractile1 and bearing a terminal battery of nematocysts4 ,the gonads are developed typically beneath the radial canals or below the stomach or its pouches1 often stretching as long bands on to the base of the manubrium4 ,in ,octorchidae 7fig4 #eh7 each such band is interrupted1 forming one mass at the base of the manubrium and another below the radial canal in each radius1 in all eight separate gonad-masses1 as the name implies4 ,in some ,leptomedusae excretory marginal tubercles are developed on the ring-canal4 ,classification4---,as in the ,gymnoblastea1 the difficulty of uniting the hydroid and medusan systems into one scheme of classification is very great in the present state of our knowledge4 ,in a great many ,leptomedusae the hydroid stage is as yet unknown1 and it is by no means certain even that they possess one4 ,it is quite possible that some of these medusae will be found to be truly hypogenetic1 that is to say1 with a life-cycle secondarily simplified by suppression of metagenesis4 ,at present1 ten recent and one extinct family of ,calyptoblastea 7,leptomedusae7 may be recognized provisionally3 #a4 ,eucopidae 7figs4 #ee1 #ei74--,trophosome with stalked hydrothecae2 gonosome1 free medusae with otocysts and four1 rarely six or eight1 unbranched radial canals4 ,two of the commonest ,british hydroids belong to this family1 ,obelia and ,clytia4 ,obelia forms numerous polyserial stems of the characteristic zigzag pattern growing up from a creeping basal stolon1 and buds the medusa of the same name4 ,in ,clytia the polyps arise singly from the stolon1 and the medusa is known as ,phialidium 7fig4 #ei74 #b4 ,aequoridae4--,trophosome only known in one genus 7,polycanna71 and similar to the preceding2 gonosome1 free medusae with otocysts and with at least eight radial canals1 often a hundred or more1 simple or branched4 ,aequorea is a common medusa4 #c4 ,thaumantidae4--,trophosome only known in one genus 7,thaumantias71 similar to that of the ,eucopidae2 gonosome1 free medusae with otocysts inconspicuous or absent1 with usually four1 sometimes eight1 rarely more than eight1 radial canals1 simple and unbranched1 along which the gonads are developed1 with numerous tentacles bearing ocelli and with marginal sense-clubs4 ,laodice and ,thaumantias are representative genera4 #d4 ,berenicidae4--,trophosome unknown2 gonosome1 free medusae1 with four or six radial canals1 bearing the gonads1 with numerous tentacles1 between which occur sense-clubs1 without otocysts4 ,berenice1 ,staurodiscus1 c4 ,illustration3 ,after ,haeckel1 ,system der ,medusen1 by permission of ,gustav ,fischer4 ,,fig4 #eh4--,octorchandra canariensis1 from life4 #e4 ,polyorchidae4--,trophosome unknown2 gonosome1 free medusae of deep form1 with radial canals branched in a feathery manner1 and bearing gonads on the main canal1 but not on the branches1 with numerous hollow tentacles bearing ocelli1 and without otocysts4 ,polyorchis1 ,spirocodon4 #f4 ,campanularidae4--,trophosome as in ,eucopidae2 gonosome1 sessile gonophores4 ,many common or well-known genera belong here1 such as ,halecium1 ,campanularia1 ,gonothyraea1 c4 #g4 ,lafoidae4--,trophosome as in the preceding2 gonosome1 free medusae or gonophores1 the medusae with large open otocysts4 ,the hydroid genus ,lafoa is remarkable for producing gonothecae on the hydrorhiza1 each containing a blastostyle which bears a single gonophore2 this portion of the colony was formerly regarded as an independent parasitic hydroid1 and was named ,coppinia4 ,medusan genera are ,mitrocoma1 ,halopsis1 ,tiaropsis 7fig4 #bi1 c474 7,so far as the characters of the trophosome are concerned1 the seven preceding families are scarcely distinguishable1 and they form a section apart1 contrasting sharply with the families next to be mentioned1 in none of which are free medusae liberated from the colony1 so that only the characters of the trophosome need be considered47 ,illustration3 ,after ,e4 ,t4 ,browne1 ,proc4 ,zool4 ,soc4 of ,london1 #ahif4 ,,fig4 #ei4--,three stages in the development of ,phialidium temporarium4 a1 ,the youngest stage1 is magnified about #bb diam42 b1 older1 is magnified about #h diam42 c1 the adult medusa1 is magnified4 #h4 ,sertularidae4--,hydrothecae sessile1 biserial1 alternating or opposite on the stem4 ,sertularia and ,sertularella are two very common genera of this family4 #i4 ,plumularidae4--,hydrothecae sessile1 biserial on the main stem1 uniserial on the lateral branches or pinnules1 which give the colony its characteristic feathery form2 with nematophores4 ,a very abundant and prolific family2 well-known ,british genera are ,plumularia1 ,antennularia and ,aglaophenia4 #aj4 ,hydroceratinidae4--,this family contains the single ,australian species ,clathrozoon wilsoni ,spencer1 in which a massive hydrorhiza bears sessile hydrothecae1 containing hydranths each with a single tentacle1 and numerous nematophores4 ,see ,w4 ,b4 ,spencer #ec4 #aa4 ,dendrograptidae1 containing fossil 7,silurian7 genera1 such as ,dendrograptus and ,thamnograptus1 of doubtful affinities4 ,illustration3 ,,fig4 #fj4--,portion of the calcareous corallum of ,millepora nodosa1 showing the cyclical arrangement of the pores occupied by the persons or hydranths4 ,about twice the natural size4 7,from ,moseley47 ,,order ,,iii4 ,hydrocorallinae4--,metagenetic colony-forming ,hydromedusae1 in which the polyp-colony forms a massive1 calcareous corallum into which the polyps can be retracted2 polyp-individuals always of two kinds1 gastrozoids and dactylozoids2 gonosome either free medusae or sessile gonophores4 ,the trophosome consists of a mass of coenosarcal tubes anastomosing in all planes4 ,the interspaces between the tubes are filled up by a solid mass of lime1 consisting chiefly of calcium carbonate1 which replaces the chitinous perisarc of ordinary hydroids and forms a stony corallum or coenosteum 7fig4 #fj74 ,the surface of the coenosteum is covered by a layer of common ectoderm1 containing large nematocysts1 and is perforated by pores of two kinds1 gastropores and dactylopores1 giving exit to gastrozoids and dactylozoids respectively1 which are lodged in vertical pore-canals of wider calibre than the coenosarcal canals of the general network4 ,the coenosteum increases in size by new growth at the surface2 and in the deeper1 older portions of massive forms the tissues die off after a certain time1 only the superficial region retaining its vitality down to a certain depth4 ,the living tissues at the surface are cut off from the underlying dead portions by horizontal partitions termed tabulae1 which are formed successively as the coenosteum increases in age and size4 ,if the coenosteum of ,millepora be broken across1 each pore-canal 7perhaps better termed a polyp-canal7 is seen to be interrupted by a series of transverse partitions1 representing successive periods of growth with separation from the underlying dead portions4 ,illustration3 ,,fig4 #fa4--;,enlarged view of the surface of a living ,millepora1 showing five dactylozooids surrounding a central gastrozooid4 7,from ,moseley47 ,besides the wider vertical pore-canals and the narrower1 irregular coenosarcal canals1 the coenosteum may contain1 in its superficial portion1 chambers or ampullae1 in which the reproductive zoids 7medusae or gonophores7 are budded from the coenosarc4 ,the gastropores and dactylopores are arranged in various ways at the surface1 a common pattern being the formation of a cyclosystem 7fig4 #fj71 in which a central gastrozoid is surrounded by a ring of dactylozoids 7fig4 #fa74 ,in such a system the dactylopores may be confluent with the gastropore1 so that the entire cyclosystem presents itself as a single aperture subdivided by radiating partitions1 thus having a superficial resemblance to a madreporarian coral with its radiating septa 7figs4 #fb and #fc74 ,illustration3 ,,fig4 #fb4--;,diagrams illustrating the successive stages in the development of the cyclosystems of the ,stylasteridae4 7,after ,moseley47 #a1 ,sporadopora dichotoma4 #b1 #c1 ,allopora nobilis4 #d1 ,allopora profunda4 #e1 ,allopora miniacea4 #f1 ,astylus subviridis4 #g1 ,distichopora coccinea4 s1 ,style4 dp1 ,dactylopore4 gp1 ,gastropore4 b1 ,in fig4 #f1 inner horseshoe-shaped mouth of gastropore4 ,the gastrozoids usually bear short capitate tentacles1 four1 six or twelve in number2 but in ,astylus 7fig4 #fc7 they have no tentacles4 ,the dactylozoids have no mouth2 in ,milleporidae they have short capitate tentacles1 but lack tentacles in ,stylasteridae4 ,the gonosome consists of free medusae in ,milleporidae1 which are budded from the apex of a dactylozoid in ,millepora murrayi1 but in other species from the coenosarcal canals4 ,the medusae are produced by direct budding1 without an entocodon in the bud4 ,they are liberated in a mature condition1 and probably live but a short time1 merely sufficient to spread the species4 ,the manubrium bearing the gonads is mouthless1 and the umbrella is without tentacles1 sense-organs1 velum or radial canals4 ,in the ,stylasteridae sessile gonophores are formed1 always by budding from the coenosarc4 ,in ,distichopora the gonophores have radial canals1 but in other genera they are sporosacs with no trace of medusoid structure4 ,illustration3 ,,fig4 #fc4--,portion of the corallum of ,astylus subviridis 7one of the ,stylasteridae71 showing cyclosystems placed at intervals on the branches1 each with a central gastropore and zone of slit-like dactylopores4 7,after ,moseley47 ,classification4---,two families are known3-- #a4 ,milleporidae4--,coenosteum massive1 irregular in form2 pores scattered irregularly or in cyclosystems1 without styles1 with transverse tabulae2 free medusae4 ,a single genus1 ,millepora 7figs4 #fj1 #fa74 #b4 ,stylasteridae4--,coenosteum arborescent1 sometimes fanlike1 with pores only on one face1 or on the lateral margins of the branches2 gastropores with tabulae only in two genera1 but with 7except in ,astylus7 a style1 i4e4 a conical1 thorn-like projection from the base of the pore1 sometimes found also in dactylopores2 sessile gonophores4 ,sporadopora has the pores scattered irregularly4 ,distichopora has the pores arranged in rows4 ,stylaster has cyclosystems4 ,in ,allopora the cyclostems resemble the calyces of ,anthozoan corals4 ,in ,cryptohelia the cyclosystem is covered by a cap or operculum4 ,in ,astylus 7fig4 #fc7 styles are absent4 ,affinities of the ,hydrocorallinae4--,there can be no doubt that the forms comprised in this order bear a close relationship to the ,hydroidea1 especially the sub-order ,gymnoblastea1 with which they should perhaps be classed in a natural classification4 ,a hydrocoralline may be regarded as a form of hydroid colony in which the coenosarc forms a felt-work ramifying in all planes1 and in which the chitinous perisarc is replaced by a massive calcareous skeleton4 ,so far as the trophosome is concerned1 the step from an encrusting hydroid such as ,hydractinia to the hydrocoralline ,millepora is not great4 ,hickson considers that the families ,milleporidae and ,stylasteridae should stand quite apart from one another and should not be united in one order4 ,the nearest approach to the ,stylasteridae is perhaps to be found in ,ceratella1 with its arborescent trophosome formed of anastomosing coenosarcal tubes supported by a thick perisarc and covered by a common ectoderm4 ,ceratella stands in much the same relation to the ,stylasteridae that ,hydractinia does to the ,milleporidae1 in both cases the chitinous perisarc being replaced by the solid coenosteum to which the hydrocorallines owe the second half of their name4 ,,order ,,iv4 ,graptolitoidea 7,rhabdophora1 ,allman74--,this order has been constituted for a peculiar group of palaeozoic fossils1 which have been interpreted as the remains of the skeletons of ,hydrozoa of an extinct type4 ,a typical graptolite consists of an axis bearing a series of tooth-like projections1 like a saw4 ,each such projection is regarded as representing a cup or hydrotheca1 similar to those borne by a calyptoblastic hydroid1 such as ,sertularia4 ,the supposed hydrothecae may be present on one side of the axis only 7monoprionid7 or on both sides 7diprionid72 the first case may be conjectured to be the result of uniserial 7helicoid7 budding1 the second to be produced by biserial 7scorpioid7 budding4 ,in one division 7,retiolitidae7 the axis is reticulate4 ,in addition to the stems bearing cups1 there are found vesicles associated with them1 which have been interpreted as gonothecae or as floats1 that is to say1 air-bladders1 acting as hydrostatic organs for a floating polyp-colony4 ,since no graptolites are known living1 or1 indeed1 since palaeozoic times1 the interpretation of their structure and affinities must of necessity be extremely conjectural1 and it is by no means certain that they are ,hydrozoa at all4 ,it can only be said that their organization1 so far as the state of their preservation permits it to be ascertained1 offers closer analogies with the ,hydrozoa1 especially the ,calyptoblastea1 than with any other existing group of the animal kingdom4 ,see the treatise of ,delage and ,hrouard 7,,hydrozoa1 #d71 and the article ,,graptolites4 ,,order ,v4 ,trachylinea4--,hydromedusae without alternation of generations1 i4e4 without a hydroid phase2 the medusa develops directly from the actinula larva1 which may1 however1 multiply by budding4 ,medusae with sense-organs represented by otocysts derived from modified tentacles 7tentaculocysts71 containing otoliths of endodermal origin1 and innervated from the ex-umbral nerve-ring4 ,this order1 containing the typical oceanic medusae1 is divided into two sub-orders4 ,,sub-,,order #a4 ,,trachomedusae4--,tentacles given off from the margin of the umbrella1 which is entire1 i4e4 not lobed or indented2 tentaculocysts usually enclosed in vesicles2 gonads on the radial canals4 ,the medusae of this order are characterized by the tough1 rigid consistence of the umbrella1 due partly to the dense nature of the mesogloea1 partly to the presence of a marginal rim of chondral tissue1 consisting of thickened ectoderm containing great numbers of nematocysts1 and forming1 as it were1 a cushion-tyre supporting the edge of the umbrella4 ,prolongations from the rim of chondral tissue may form clasps or peronia supporting the tentacles4 ,the tentacles are primarily four in number1 perradial1 alternating with four interradial tentaculocysts1 but both tentacles and sense-organs may be multiplied and the primary perradii may be six instead of four 7fig4 #bf74 ,the tentacles are always solid1 containing an axis of endoderm-cells resembling notochordal tissue or plant-parenchyma1 and are but moderately flexible4 ,the sense-organs are tentaculocysts which are usually enclosed in vesicles and may be sunk far below the surface4 ,the gonads are on the radial canals or on the stomach 7,ptychogastridae71 and each gonad may be divided into two by a longitudinal sub-umbral muscle-tract4 ,the radial canals are four1 six1 eight or more1 and in some genera blindly-ending centripetal canals are present 7fig4 #bf74 ,the stomach may be drawn out into the manubrium1 forming a proboscis 7,magenstiel7 of considerable length4 ,the development of the ,trachomedusae1 so far as it is known1 shows an actinula-stage which is either free 7larval7 or passed over in the egg 7foetal7 as in ,geryonia2 in no case does there appear to be a free planula-stage4 ,the actinula1 when free1 may multiply by larval budding1 but in all cases both the original actinula and all its descendants become converted into medusae1 so that there is no alternation of generations4 ,in ,gonionemus the actinula becomes attached and polyp-like and reproduces by budding4 ,illustration3 ,after ,haeckel1 ,system der ,medusen1 by permission of ,gustav ,fischer4 ,,fig4 #fd4 ,olindias mlleri4 ,the ,trachomedusae are divided into the following families3 #a4 ,petasidae 7,petachnidae74--,four radial canals1 four gonads2 stomach not prolonged into the manubrium1 which is relatively short2 tentaculocysts free4 ,petasus and other genera make up this family1 founded by ,haeckel1 but no other naturalist has ever seen them1 and it is probable that they are simply immature forms of other genera4 #b4 ,olindiadae1 with four radial canals and four gonads2 manubrium short2 ring-canals giving off blind centripetal canals2 tentaculocysts enclosed4 ,olindias mlleri 7fig4 #fd7 is a common ,mediterranean species4 ,other genera are ,aglauropsis1 ,gossea and ,gonionemus2 the last named bears adhesive suckers on the tentacles4 ,some doubt attaches to the position of this family4 ,it has been asserted that the tentaculocysts are entirely ectodermal and that either the family should be placed amongst the ,leptomedusae1 or should form1 together with certain ,leptomedusae1 an entirely distinct order4 ,in ,gonionemus1 however1 the concrement-cells are endodermal4 #c4 ,trachynemidae4--,eight radial canals1 eight gonads1 stomach not prolonged into manubrium2 tentaculocysts enclosed4 ,rhopalonema1 ,trachynema1 c4 ,illustration3 ,after ,e4 ,t4 ,browne1 ,proc4 ,zool4 ,soc4 of ,london4 ,,fig4 #fe4--;,aglantha rosea 7,forbes71 a ,british medusa4 #d4 ,ptychogastridae 7,pectyllidae74--,as in the preceding1 but with suckers on the tentacles4 ,ptychogastria ,allman 7,pectyllis71 a deep-sea form4 #e4 ,aglauridae4--,eight radial canals1 two1 four or eight gonads2 tentacles numerous2 tentaculocysts free2 stomach prolonged into manubrium4 ,aglaura1 ,aglantha 7fig4 #fe71 c41 with eight gonads2 ,stauraglaura with four2 ,persa with two4 ,amphogona1 hermaphrodite1 with male and female gonads on alternating radial canals4 #f4 ,geryonidae4--,four or six radial canals2 gonads band-like2 stomach prolonged into a manubrium of great length2 tentaculocysts enclosed4 ,liriope1 c41 with four radial canals2 ,geryonia1 ,carmarina 7fig4 #bf71 c41 with six4 #g4 ,halicreidae4--,eight very broad radial canals2 ex-umbrella often provided with lateral outgrowths2 tentacles differing in size1 but in a single row4 ,halicreas4 ,,sub-,,order #b4 ,,narcomedusae4--,margin of the umbrella-lobed1 tentacles arising from the ex-umbrella at some distance from the margin2 tentaculocysts exposed1 not enclosed in vesicles2 gonads on the sub-umbral floor of the stomach or of the gastric pouches4 ,illustration3 ,,fig4 #ff4--;,cunina rhododactyla1 one of the ,narcomedusae4 7,after ,haeckel47 c1 ,circular canal4 h1 ,otoporpae or centripetal process of the marginal cartilaginous ring connected with tentaculocyst4 k1 ,stomach4 l1 ,jelly of the disk4 r1 ,radiating canal 7pouch of stomach74 tt1 ,tentacles4 tw1 ,tentacle root4 ,the ,narcomedusae exhibit peculiarities of form and structure which distinguish them at once from all other ,hydromedusae4 ,the umbrella is shallow and has the margin supported by a rim of thickened ectoderm1 as in the ,trachomedusae1 but not so strongly developed4 ,the tentacles are not inserted on the margin of the umbrella1 but arise high up on the ex-umbral surface1 and the umbrella is prolonged into lobes corresponding to the interspaces between the tentacles4 ,the condition of things can be imagined by supposing that in a medusa primitively of normal build1 with tentacles at the margin1 the umbrella has grown down past the insertion of the tentacles4 ,as a result of this extension of the umbrellar margin1 all structures belonging to this region1 namely1 the ring-canal1 the nerve-rings1 and the rim of thickened ectoderm1 do not run an even course1 but are thrown into festoons1 caught up under the insertion of each tentacle in such a way that the ring-canal and its accompaniments form in each notch of the umbrellar margin an inverted ,v1 the apex of which corresponds to the insertion of the tentacle2 in some cases the limbs of the ,v may run for some distance parallel to one another1 and may be fused into one1 giving a figure better compared to an inverted ,y4 ,thus the ectodermal rim runs round the edge of each lobe of the umbrella and then passes upwards towards the base of the tentacle from the re-entering angle between two adjacent lobes1 to form with its fellow of the next lobe a tentacle-clasp or peronium1 i4e4 a streak of thickened ectoderm supporting the tentacle4 ,similarly the ring-canal runs round the edge of the lobe as the so-called festoon-canal1 and then runs upwards under the peronium to the base of the tentacle as one of a pair of peronial canals1 the limbs of the ,v-like figure already mentioned4 ,the nerve-rings have a similar course4 ,the tentaculocysts are implanted round the margins of the lobes of the umbrella and may be supported by prolongations of the ectodermal rim termed otoporpae 7,gehrspangen74 ,the radial canals are represented by wide gastric pouches1 and may be absent1 so that the tentacles arise directly from the stomach 7,solmaridae74 ,the tentacles are always solid1 as in ,trachomedusae4 ,the development of the ,narcomedusae is in the main similar to that of the ,trachomedusae1 but shows some remarkable features4 ,in ,aeginopsis a planula is formed by multipolar immigration4 ,the two ends of the planula become greatly lengthened and give rise to the two primary tentacles of the actinula1 of which the mouth arises from one side of the planula4 ,hence the principal axis of the future medusa corresponds1 not to the longitudinal axis of the planula1 but to a transverse axis4 ,this is in some degree parallel to the cases described above1 in which a planula gives rise to the hydrorhiza1 and buds a polyp laterally4 ,in ,cunina and allied genera the actinula1 formed in the manner described1 has a hypostome of great length1 quite disproportionate to the size of the body1 and is further endowed with the power of producing buds from a stolon arising from the aboral side of the body4 ,in these species the actinula is parasitic upon another medusa2 for instance1 ,cunoctantha octonaria upon ,turritopsis1 ,c4 proboscidea upon ,liriope or ,geryonia4 ,the parasite effects a lodgment in the host either by invading it as a free-swimming planula1 or1 apparently1 in other cases1 as a spore-embryo which is captured and swallowed as food by the host4 ,the parasitic actinula is found attached to the proboscis of the medusa2 it thrusts its greatly elongated hypostome into the mouth of the medusa and nourishes itself upon the food in the digestive cavity of its host4 ,at the same time it produces buds from an aboral stolon4 ,the buds become medusae by the direct method of budding described above4 ,in some cases the buds do not become detached at once1 but the stolon continues to grow and to produce more buds1 forming a bud-spike 7,knospenhre71 which consists of the axial stolon bearing medusa-buds in all stages of development4 ,in such cases the original parent-actinula does not itself become a medusa1 but remains arrested in development and ultimately dies off1 so that a true alternation of generations is brought about4 ,it is in these parasitic forms that we meet with the method of reproduction by sporogony described above4 ,in other ,narcomedusae1 e4g4 ,cunoctantha fowleri ,browne1 buds are formed from the sub-umbrella on the under side of the stomach pouches1 where later the gonads are developed4 ,classification4--,three families of ,narcomedusae are recognized 7see ,o4 ,maas #dj73 ,illustration3 ,after ,o4 ,maas1 ,craspedoten ,medusen der ,siboga ,expedition1 by permission of ,e4 ,s4 ,brill ,co4 ,,fig4 #fg4--,solmundella bitentaculata 7,quoy and ,gaimard74 #a4 ,cunanthidae4--,with broad gastric pouches which are simple1 i4e4 undivided1 and pernemal1 i4e4 correspond in position with the tentacles4 ,cunina 7fig4 #ff7 with more than eight tentacles2 ,cunoctantha with eight tentacles1 four perradial1 four interradial4 #b4 ,aeginidae4--,radii a multiple of four1 with radial gastric pouches bifurcated or subdivided2 the tentacles are implanted in the notch between the two subdivisions of each 7primary7 gastric pouch1 hence the 7secondary7 gastric pouches appear to be internemal in position1 i4e4 to alternate in position with the tentacles4 ,aegina1 with four tentacles and eight pouches2 ,aeginura 7fig4 #be71 with eight tentacles and sixteen pouches2 ,solmundella 7fig4 #fg71 with two tentacles and eight pouches2 ,aeginopsis 7fig4 #bc71 with two or four tentacles and sixteen pouches4 #c4 ,solmaridae4--,no gastric pouches2 the numerous tentacles arise direct from the stomach1 into which also the peronial canals open1 so that the ring-canal is cut up into separate festoons4 ,solmaris1 ,pegantha1 ,polyxenia1 c4 ,to this family should be referred1 probably1 the genus ,hydroctena1 described by ,c4 ,dawydov #aa;a and regarded by him as intermediate between ,hydromedusae and ,ctenophora4 ,see ,o4 ,maas #ce4 ,appendix to the ,trachylinae4 ,of doubtful position1 but commonly referred to the ,trachylinae1 are the two genera of fresh-water medusae1 ,limnocodium and ,limnocnida4 ,limnocodium sowerbyi was first discovered in the ,victoria regia tank in the ,botanic ,gardens1 ,regent's ,park1 ,london4 ,since then it has been discovered in other botanic gardens in various parts of ,europe1 its two most recent appearances being at ,lyons 7#aija7 and ,munich 7#aije71 occurring always in tanks in which the ,victoria regia is cultivated1 a fact which indicates that tropical ,south ,america is its original habitat4 ,in the same tanks a small hydroid1 very similar to ,microhydra1 has been found1 which bears medusa-buds and is probably the stock from which the medusa is budded4 ,it is a remarkable fact that all specimens of ,limnocodium hitherto seen have been males2 it may be inferred from this either that only one polyp-stock has been introduced into ,europe1 from which all the medusae seen hitherto have been budded1 or perhaps that the female medusa is a sessile gonophore1 as in ,pennaria4 ,the male gonads are carried on the radial canals4 ,limnocnida tanganyicae was discovered first in ,lake ,tanganyika1 but has since been discovered also in ,lake ,victoria and in the river ,niger4 ,it differs from ,limnocodium in having practically no manubrium but a wide mouth two-thirds the diameter of the umbrella across4 ,it buds medusae from the margin of the mouth in ,may and ,june1 and in ,august and ,september the gonads are formed in the place where the buds arose4 ,the hydroid phase1 if any1 is not known4 ,both these medusae have sense-organs of a peculiar type1 which are said to contain an endodermal axis like the sense-organs of ,trachylinae1 but the fact has recently been called in question for ,limnocodium by ,s4 ,goto1 who considers the genus to be allied to ,olindias4 ,allman1 on the other hand1 referred ,limnocodium to the ,leptomedusae4 ,in this connexion must be mentioned1 finally1 the medusae budded from the fresh-water polyp ,microhydra4 ,the polyp-stages of ,limnocodium and ,microhydra are extremely similar in character4 ,in both cases the hydranth is extremely reduced and has no tentacles1 and the polyp forms a colony by budding from the base4 ,in ,limnocodium the body secretes a gelatinous mucus to which adhere particles of mud1 c41 forming a protective covering4 ,in ,microhydra no such protecting case is formed4 ,in view of the great resemblance between ,microhydra and the polyp of ,limnocodium1 it might be expected that the medusae to which they give origin would also be similar4 ,as yet1 however1 the medusa of ,microhydra has only been seen in an immature condition1 but it shows some well-marked differences from ,limnocodium1 especially in the structure of the tentacles1 which furnish useful characters for distinguishing species amongst medusae4 ,the possession of a polyp-stage by ,limnocodium and ,microhydra furnishes an argument against placing them in the ,trachylinae4 ,their sense-organs require renewed investigations4 7,browne #aj and #aj;a47 ,,order ,,vi4 ,siphonophora4--,pelagic floating ,hydrozoa with great differentiation of parts1 each performing a special function2 generally regarded as colonies showing differentiation of individuals in correspondence with a physiological division of labour4 ,illustration3 ,,fig4 #fh4--;,diagram showing possible modifications of medusiform and hydriform persons of a colony of ,siphonophora4 ,the thick black line represents endoderm1 the thinner line ectoderm4 7,after ,allman47 n1 ,pneumatocyst4 k1 ,nectocalyces 7swimming bells74 l1 ,hydrophyllium 7covering-piece74 i1 ,generative medusiform person4 g1 ,palpon with attached palpacle1 h4 e1 ,siphon with branched grappling tentacle1 f4 m1 ,stem4 ,a typical ,siphonophore is a stock or cormus consisting of a number of appendages placed in organic connexion with one another by means of a coenosarc4 ,the coenosarc does not differ in structure from that already described in colonial ,hydrozoa4 ,it consists of a hollow tube1 or tubes1 of which the wall is made up of the two body-layers1 ectoderm and endoderm1 and the cavity is a continuation of the digestive cavities of the nutritive and other appendages1 i4e4 of the coelenteron4 ,the coenosarc may consist of a single elongated tube or stolon1 forming the stem or axis of the cormus on which1 usually1 the appendages are arranged in groups termed cormidia2 or it may take the form of a compact mass of ramifying1 anastomosing tubes1 in which case the cormus as a whole has a compact form and cormidia are not distinguishable4 ,in the ,disconectae the coenosarc forms a spongy mass1 the centradenia1 which is partly hepatic in function1 forming the so-called liver1 and partly excretory4 ,the appendages show various types of form and structure corresponding to different functions4 ,the cormus is always differentiated into two parts2 an upper portion termed the nectosome1 in which the appendages are locomotor or hydrostatic in function1 that is to say1 serve for swimming or floating2 and a lower portion termed the siphosome1 bearing appendages which are nutritive1 reproductive or simply protective in function4 ,divergent views have been held by different authors both as regards the nature of the cormus as a whole1 and as regards the homologies of the different types of appendages borne by it4 ,the general theories of ,siphonophoran morphology are discussed below1 but in enumerating the various types of appendages it is convenient to discuss their morphological interpretation at the same time4 ,illustration3 ,after ,a4 ,agassiz1 from ,lankester's ,treatise on ,zoology4 ,,fig4 #fi4--,porpita1 seen from above1 showing the pneumatophore and expanded palpons4 ,in the nectosome one or more of the following types of appendage occur3-- #a4 ,swimming-bells1 termed nectocalyces or nectophores 7fig4 #fh1 k71 absent in ,chondrophorida and ,cystophorida2 they are contractile and resemble1 both in appearance1 structure and function1 the umbrella of a medusa1 with radial canals1 ring-canal and velum2 but they are without manubrium1 tentacles or sense-organs1 and are always bilaterally symmetrical1 a peculiarity of form related with the fact that they are attached on one side to the stem4 ,a given cormus may bear one or several nectocalyces1 and by their contractions they propel the colony slowly along1 like so many medusae harnessed together4 ,in cases where the cormus has no pneumatophore the topmost swimming bell may contain an oil-reservoir or oleocyst4 #b4 ,the pneumatophore or air-bladder 7fig4 #fh1 n71 for passive locomotion1 forming a float which keeps the cormus at or near the surface of the water4 ,the pneumatophore arises from the ectoderm as a pit or invagination1 part of which forms a gas-secreting gland1 while the rest gives rise to an air-sack lined by a chitinous cuticle4 ,the orifice of invagination forms a pore which may be closed up or may form a protruding duct or funnel4 ,as in the analogous swim-bladder of fishes1 the gas in the pneumatophore can be secreted or absorbed1 whereby the specific gravity of the body can be diminished or increased1 so as to cause it to float nearer the surface or at a deeper level4 ,never more than one pneumatophore is found in a cormus1 and when present it is always situated at the highest point above the swimming bells1 if these are present also4 ,in ,velella the pneumatophore becomes of complex structure and sends air-tubes1 lined by a chitin and resembling tracheae1 down into the compact coenosarc1 thus evidently serving a respiratory as well as a hydrostatic function4 ,divergent views have been held as to the morphological significance of the pneumatophore4 ,e4 ,haeckel regarded the whole structure as a glandular ectodermal pit formed on the ex-umbral surface of a medusa-person4 ,c4 ,chun and1 more recently1 ,r4 ,woltereck #ei1 on the other hand1 have shown that the ectodermal pit which gives rise to the pneumatophore represents an entocodon4 ,hence the cavity of the air-sack is equivalent to a sub-umbral cavity in which no manubrium is formed1 and the pore or orifice of invagination would represent the margin of the umbrella4 ,in the wall of the sack is a double layer of endoderm1 the space between which is a continuation of the coelenteron4 ,by coalescence of the endoderm-layers1 the coelenteron may be reduced to vessels1 usually eight in number1 opening into a ring-sinus surrounding the pore4 ,thus the disposition of the endoderm-cavities is roughly comparable to the gastrovascular system of a medusa4 ,the difference between the theories of ,haeckel and ,chun is connected with a further divergence in the interpretation of the stem or axis of the cormus4 ,haeckel regards it as the equivalent of the manubrium1 and as it is implanted on the blind end of the pneumatophore1 such a view leads necessarily to the air-sack and gland being a development on the ex-umbral surface of the medusa-person4 ,chun and ,woltereck1 on the other hand1 regard the stem as a stolo prolifer arising from the aboral pole1 that is to say1 from the ex-umbrella1 similar to that which grows out from the ex-umbral surface of the embryo of the ,narcomedusae and produces buds1 a view which is certainly supported by the embryological evidence to be adduced shortly4 ,in the siphosome the following types of appendages occur3-- #a4 ,siphons or nutritive appendages1 from which the order takes its name2 never absent and usually present in great numbers 7fig4 #fh1 e74 ,each is a tube dilated at or towards the base and containing a mouth at its extremity1 leading into a stomach placed in the dilatation already mentioned4 ,the siphons have been compared to the manubrium of a medusa-individual1 or to polyps1 and hence are sometimes termed gastrozoids4 #b4 ,palpons 7fig4 #fh1 g71 present in some genera1 especially in ,physonectae2 similar to the siphons but without a mouth1 and purely tactile in function1 hence sometimes termed dactylozoids4 ,if a distal pore or aperture is present1 it is excretory in function2 such varieties have been termed cystons by ,haeckel4 #c4 ,tentacles 7,fangfden71 always present1 and implanted one at the base of each siphon 7fig4 #fh1 f74 ,the tentacles of siphonophores may reach a great length and have a complex structure4 ,they may bear accessory filaments or tentilla 7f'71 covered thickly with batteries of nematocysts1 to which these organisms owe their great powers of offence and defence4 #d4 ,palpacles 7,tastfden71 occurring together with palpons1 one implanted at the base of each palpon 7fig4 #fh1 h74 ,each palpacle is a tactile filament1 very extensile1 without accessory filaments or nematocysts4 #e4 ,bracts 7hydrophyllia71 occur in ,calycophorida and some ,physophorida as scale-like appendages protecting other parts 7fig4 #fh1 l74 ,the mesogloea is greatly developed in them and they are often of very tough consistency4 ,by ,haeckel they are considered homologous with the umbrella of a medusa4 ,illustration3 ,from ,g4 ,h4 ,fowler1 after ,a4 ,agassiz1 ,lankester's ,treatise on ,zoology4 ,,fig4 #gj4--;,diagram of the structure of ,velella1 showing the central and peripheral thirds of a half-section of the colony1 the middle third being omitted4 ,the ectoderm is indicated by close hatching1 the endoderm by light hatching1 the mesogloea by thick black lines1 the horny skeleton of the pneumatophore and sail by dotting4 ,,bl1 ,blastostyle4 ,c1 ,centradenia4 ,d1 ,palpon4 ,,ec1 ,edge of colony prolonged beyond the pneumatophore4 ,g1 ,cavity of the large central siphon4 ,m1 ,medusoid gonophores4 ,,pn1 ,primary central chamber1 and ,,pn'1 concentric chamber of the pneumatophore1 showing an opening to the exterior and a trachea4 ,s1 ,sail4 #f4 ,gonostyles1 appendages which produce by budding medusae or gonophores1 like the blastostyles of a hydroid colony4 ,in their most primitive form they are seen in ,velella as gonosiphons1 which possess mouths like the ordinary sterile siphons and bud free medusae4 ,in other forms they have no mouths4 ,they may be branched1 so-called gonodendra1 and amongst them may occur special forms of palpons1 gonopalpons4 ,the gonostyles have been compared to the blastostyles of a hydroid colony1 or to the manubrium of a medusa which produces free or sessile medusa-buds4 #g4 ,gonophores1 produced either on the gonostyles already mentioned or budded1 as in hydrocorallines1 from the coenosarc1 i4e4 the stem 7fig4 #fh1 i474 ,they show every transition between free medusae and sporosacs1 as already described1 for hydroid colonies4 ,thus in ,velella free medusae are produced1 which have been described as an independent genus of medusae1 ,chrysomitra4 ,in other types the medusae may be set free in a mature condition as the so-called genital swimming bells1 comparable to the ,globiceps of ,pennaria4 ,the most usual condition1 however1 is that in which sessile medusoid gonophores or sporosacs are produced4 ,the various types of appendages described in the foregoing may be arranged in groups termed cormidia4 ,in forms with a compact coenosarc such as ,velella1 ,physalia1 c41 the separate cormidia cannot be sharply distinguished1 and such a condition is described technically as one with scattered cormidia4 ,in forms in which1 on the other hand1 the coenosarc forms an elongated1 tubular axis or stem1 the appendages are arranged as regularly recurrent cormidia along it1 and the cormidia are then said to be ordinate4 ,in such cases the oldest cormidia1 that is to say1 those furthest from the nectosome1 may become detached 7like the segments or proglottides of a tape-worm7 and swim off1 each such detached cormidium then becoming a small free cormus which1 in many cases1 has been given an independent generic name4 ,a cormidium may contain a single nutritive siphon 7monogastric7 or several siphons 7polygastric73 ,illustration3 ,from ,g4 ,h4 ,fowler1 after ,g4 ,cuvier1 ,lankester's ,treatise on ,zoology4 ,,fig4 #ga4--,upper surface of ,velella1 showing pneumatophore and sail4 ,the following are some of the forms of cormidia that occur3-- #a4 ,the eudoxome 7,calycophorida71 consisting of a bract1 siphon1 tentacle and gonophore2 when free it is known as ,eudoxia4 #b4 ,the ersaeome 7,calycophorida71 made up of the same appendages as the preceding type but with the addition of a nectocalyx2 when free termed ,ersaea4 #c4 ,the rhodalome of some ,rhodalidae1 consisting of siphon1 tentacle and one or more gonophores4 #d4 ,the athorome of ,physophora1 c41 consisting of siphon1 tentacle1 one or more palpons with palpacles1 and one or more gonophores4 #e4 ,the crystallome of ,anthemodes1 c41 similar to the athorome but with the addition of a group of bracts4 ,illustration3 ,,fig4 #gb4--;,a1 ,diphyes campanulata2 ,b1 a group of appendages 7cormidium7 of the same ,diphyes4 7,after ,c4 ,gegenbaur47 a1 ,axis of the colony4 m1 ,nectocalyx4 c1 ,sub-umbral cavity of nectocalyx4 v1 ,radial canals of nectocalyx4 o1 ,orifice of nectocalyx4 t1 ,bract4 n1 ,siphon4 g1 ,gonophore4 i1 ,tentacle4 ,embryology of the ,siphonophora4--,the fertilized ovum gives rise to a parenchymula1 with solid endoderm1 which is set free as a free-swimming planula larva1 in the manner already described 7see ,,hydrozoa74 ,the planula has its two extremities dissimilar 7,bipolaria-larva74 ,the subsequent development is slightly different according as the future cormus is headed by a pneumatophore 7,physophorida1 ,cystophorida7 or by a nectocalyx 7,calycophorida74 7i47 ,physophorida1 for example ,halistemma 7,c4 ,chun1 ,,hydrozoa #a74 ,the planula becomes elongated and broader towards one pole1 at which a pit or invagination of the ectoderm arises4 ,next the pit closes up to form a vesicle with a pore1 and so gives rise to the pneumatophore4 ,from the broader portion of the planula an outgrowth arises which becomes the first tentacle of the cormus4 ,the endoderm of the planula now acquires a cavity1 and at the narrower pole a mouth is formed1 giving rise to the primary siphon4 ,thus from the original planula three appendages are1 as it were1 budded off1 while the planula itself mostly gives rise to coenosarc1 just as in some hydroids the planula is converted chiefly into hydrorhiza4 7ii47 ,calycophorida1 for example1 ,muggiaea4 ,the planula develops1 on the whole1 in a similar manner1 but the ectodermal invagination arises1 not at the pole of the planula1 but on the side of its broader portion1 and gives rise1 not to a pneumatophore1 but to a nectocalyx1 the primary swimming bell or protocodon 7,fallschirm7 which is later thrown off and replaced by secondary swimming bells1 metacodons1 budded from the coenosarc4 ,from a comparison of the two embryological types there can be no doubt on two points2 first1 that the pneumatophore and the protocodon are strictly homologous1 and1 therefore if the nectocalyx is comparable to the umbrella of a medusa1 as seems obvious1 the pneumatophore must be so too2 secondly1 that the coenosarcal axis arises from the ex-umbrella of the medusa and cannot be compared to a manubrium1 but is strictly comparable to the bud-spike of a ,narcomedusan4 ,theories of ,siphonophore ,morphology4--,the many theories that have been put forward as to the interpretation of the cormus and the various parts are set forth and discussed in the treatise of ,y4 ,delage and ,e4 ,hrouard 7,,hydrozoa #d7 and more recently by ,r4 ,woltereck #ei1 and only a brief analysis can be given here4 ,illustration3 ,after ,c4 ,gegenbaur4 ,,fig4 #gc4--,physophora hydrostatica4 a1 ,pneumatocyst4 t1 ,palpons4 a1 ,axis of the colony4 m1 ,nectocalyx4 o1 ,orifice of nectocalyx4 n1 ,siphon4 g1 ,gonophore4 i1 ,tentacle4 ,in the first place the cormus has been regarded as a single individual and its appendages as organs4 ,this is the so-called polyorgan theory1 especially connected with the name of ,huxley2 but it must be borne in mind that ,huxley regarded all the forms produced1 in any animal1 between one egg-generation and the next1 as constituting in the lump one single individual4 ,huxley1 therefore1 considered a hydroid colony1 for example1 as a single individual1 and each separate polyp or medusa budded from it as having the value of an organ and not of an individual4 ,hence ,huxley's view is not so different from those held by other authors as it seems to be at first sight4 ,in more recent years ,woltereck #ei has supported ,huxley's view of individuality1 at the same time drawing a fine distinction between individual and person4 ,the individual is the product of sexual reproduction2 a person is an individual of lower rank1 which may be produced asexually4 ,a ,siphonophore is regarded as a single individual composed of numerous zoids1 budded from the primary zoid 7siphon7 produced from the planula4 ,any given zoid is a person-zoid if equivalent to the primary zoid1 an organ-zoid if equivalent only to a part of it4 ,woltereck considers the siphonophores most nearly allied to the ,narcomedusae1 producing like the buds from an aboral stolon1 the first bud being represented by the pneumatophore or protocodon1 in different cases4 ,contrasting1 in the second place1 with the polyorgan theory are the various polyperson theories which interpret the ,siphonophore cormus as a colony composed of more or fewer individuals in organic union with one another4 ,on this interpretation there is still room for considerable divergence of opinion as regards detail4 ,to begin with1 it is not necessary on the polyperson theory to regard each appendage as a distinct individual2 it is still possible to compare appendages with parts of an individual which have become separated from one another by a process of dislocation of organs4 ,thus a bract may be regarded1 with ,haeckel1 as a modified umbrella of a medusa1 a siphon as its manubrium1 and a tentacle as representing a medusan tentacle shifted in attachment from the margin to the sub-umbrella2 or a siphon may be compared with a polyp1 of which the single tentacle has become shifted so as to be attached to the coenosarc and so on4 ,some authors prefer1 on the other hand1 to regard every appendage as a separate individual1 or at least as a portion of an individual1 of which other portions have been lost or obliterated4 ,a further divergence of opinion arises from differences in the interpretation of the persons composing the colony4 ,it is possible to regard the cormus 7#a7 as a colony of medusa-persons1 7#b7 as a colony of polyp-persons1 7#c7 as composed partly of one1 partly of the other4 ,it is sufficient here to mention briefly the views put forward on this point by ,c4 ,chun and ,r4 ,haeckel4 ,chun 7,,hydrozoa #a7 maintains the older views of ,leuckart and ,claus1 according to which the cormus is to be compared to a floating hydroid colony4 ,it may be regarded as derived from floating polyps similar to ,nemopsis or ,pelagohydra1 which by budding produce a colony of polyps and also form medusa-buds4 ,the polyp-individuals form the nutritive siphosome or trophosome4 ,the medusa-buds are either fertile or sterile4 ,if fertile they become free medusae or sessile gonophores4 ,if sterile they remain attached and locomotor in function1 forming the nectosome1 the pneumatophore and swimming-bells4 ,haeckel1 on the other hand1 is in accordance with ,balfour in regarding a ,siphonophore as a medusome1 that is to say1 as a colony composed of medusoid persons or organs entirely4 ,haeckel considers that the ,siphonophores have two distinct ancestral lines of evolution3 #a4 ,in the ,disconanthae1 i4e4 in such forms as ,velella1 ,porpita1 c41 the ancestor was an eight-rayed medusa 7,disconula7 which acquired a pneumatophore as an ectodermal pit on the ex-umbrella1 and in which the organs 7manubrium1 tentacles1 c47 became secondarily multiplied1 just as they do in ,gastroblasta as the result of incomplete fission4 ,the nearest living allies of the ancestral ,disconula are to be sought in the ,pectyllidae4 ,illustration3 ,after ,haeckel1 from ,lankester's ,treatise on ,zoology4 ,,fig4 #gd4--,stephalia corona1 a young colony4 p1 ,pneumatophore4 n1 ,nectocalyx4 l1 ,aurophore4 lo1 ,orifice of the aurophore4 s1 ,siphon4 t1 ,tentacle4 #b4 ,in the ,siphonanthae1 i4e4 in all other ,siphonophores1 the ancestral form was a ,siphonula1 a bilaterally symmetrical ,anthomedusa with a single long tentacle 7cf4 ,corymorpha71 which became displaced from the margin to the sub-umbrella4 ,the ,siphonula produced buds on the manubrium1 as many ,anthomedusae are known to do1 and these by reduction or dislocation of parts gave rise to the various appendages of the colony4 ,thus the umbrella of the ,siphonula became the protocodon1 and its manubrium1 the axis or stolon1 which1 by a process of dislocation of organs1 escaped1 as it were1 from the sub-umbrella through a cleft and became secondarily attached to the ex-umbrella4 ,it must be pointed out that1 however probable ,haeckel's theory may be in other respects1 there is not the slightest evidence for any such cleft in the umbrella having been present at any time1 and that the embryological evidence1 as already pointed out1 is all against any homology between the stem and a manubrium1 since the primary siphon does not become the stem1 which arises from the ex-umbral side of the protocodon and is strictly comparable to a stolon4 ,classification4--,the ,siphonophora may be divided1 following ,delage and ,hrouard1 into four sub-orders3 ,i4 ,,chondrophorida 7,disconectae ,haeckel1 ,tracheophysae ,chun74 ,with an apical chambered pneumatophore1 from which tracheal tubes may take origin 7fig4 #gj72 no nectocalyces or bracts2 appendages all on the lower side of the pneumatophore arising from a compact coenosarc1 and consisting of a central principal siphon1 surrounded by gonosiphons1 and these again by tentacles4 ,three families3 7#a7 ,discalidae1 for ,discalia and allied genera1 deep-sea forms not well known2 7#b7 ,porpitidae for the familiar genus ,porpita 7fig4 #fi7 and its allies2 and 7#c7 ,velellidae1 represented by the well-known genus ,velella 7figs4 #gj1 #ga71 common in the ,mediterranean and other seas4 ,,ii4 ,,calycophorida 7,calyconectae1 ,haeckel74 ,without pneumatophore1 with one1 two1 rarely more nectocalyces4 ,three families3 7#a7 ,monophyidae1 with a single nectocalyx2 examples ,muggiaea1 sometimes found in ,british seas1 ,sphaeronectes1 c42 7#b7 ,diphyidae1 with two nectocalyces2 examples ,diphyes 7fig4 #gb71 ,praya1 ,abyla1 c42 and 7#c7 ,polyphyidae1 with numerous nectocalyces2 example ,hippopodius1 ,stephanophyes and other genera4 ,illustration3 ,from ,g4 ,h4 ,fowler1 modified after ,g4 ,cuvier and ,e4 ,haeckel1 ,lankester's ,treatise on ,zoology4 ,,fig4 #ge4--;,a4 ,physalia1 general view1 diagrammatic2 ,b1 cormidium of ,physalia2 ,d1 palpon2 ,t1 palpacle2 ,g1 siphon2 ,,gp1 gonopalpon2 ,mmale1 male gonophore2 ,mfemale1 female gonophore1 ultimately set free4 ,,iii4 ,,physophorida 7,physonectae ,auronectae1 ,haeckel74 ,with an apical pneumatophore1 not divided into chambers1 followed by a series of nectocalyces or bracts4 ,a great number of families and genera are referred to this group1 amongst which may be mentioned specially--7#a7 ,agalmidae1 containing the genera ,stephanomia1 ,agalma1 ,anthemodes1 ,halistemma1 c42 7#b7 ,apolemidae1 with the genus ,apolemia and its allies2 7#c7 ,forskaliidae1 with ,forskalia and allied forms2 7#d7 ,physophoridae1 for ,physophora 7fig4 #gc7 and other genera1 7#e7 ,anthophysidae1 for ,anthophysa1 ,athorybia1 c42 and lastly the two families 7#f7 ,rhodalidae and 7#g7 ,stephalidae 7fig4 #gd71 constituting the group ,auronectae of ,haeckel4 ,the ,auronectae are peculiar deep-sea forms1 little known except from ,haeckel's descriptions1 in which the large pneumatophore has a peculiar duct1 termed the aurophore1 placed on its lower side in the midst of a circle of swimming-bells4 ,,iv4 ,,cystophorida 7,cystonectae1 ,haeckel74 ,with a very large pneumatophore not divided into chambers1 but without nectocalyces or bracts4 ,two sections can be distinguished1 the ,rhizophysina1 with long tubular coenosarc-bearing ordinate cormidia1 and ,physalina1 with compact coenosarc-bearing scattered cormidia4 ,a type of the ,rhizophysina is the genus ,rhizophysa4 ,the ,physalina comprise the families ,physalidae and ,epibulidae1 of which the types are ,physalia 7figs4 #gd1 #ge7 and ,epibulia1 respectively4 ,physalia1 known commonly as the ,portuguese man-of-war1 is remarkable for its great size1 its brilliant colours1 and its terrible stinging powers4 ,,bibliography4--,in addition to the works cited below1 see the general works cited in the article ,,hydrozoa1 in some of which very full bibliographies will be found4 #a4 ,g4 ,j4 ,allman1 ,a ,monograph of the ,gymnoblastic or ,tubularian ,hydroids1 ,ray ,society 7#ahga-ahgb72 #b4 ,a4 ,brauer1 ber die ,entwickelung von ,hydra1 ,zeitschr4 f4 wiss4 ,zool4 lii4 7#ahia71 pp4 #afi-baf1 pls4 ix4-xii42 #c4 ber die ,entstehung der ,geschlechtsprodukte und die ,entwickelung von ,tubularia mesembryanthemum ,allm41 t4c4 pp4 #eea-egi1 pls4 xxxiii4-xxxv42 #d4 ,w4 ,k4 ,brooks1 ,the ,life-,history of the ,hydromedusae3 a discussion of the ,origin of the ,medusae1 and of the significance of ,metagenesis1 ,mem4 ,boston ,soc4 ,nat4 ,hist4 iii4 7#ahhf71 pp4 #bei-dcj1 pis4 xxxvii4-xliv42 #e4 ,the ,sensory ,clubs of ,cordyli of ,laodice1 ,journ4 ,morphology1 x4 7#ahie71 pp4 #bhg-cjd1 pl4 xvii42 #f4 ,e4 ,t4 ,browne1 ,on ,british ,hydroids and ,medusae1 ,proc4 ,zool4 ,soc4 7#ahif71 pp4 #dei-ejj1 pls4 xvi41 xvii41 7#ahig71 pp4 #haf-hce1 pls4 xlviii4 xlix4 #ab text-figs42 #g4 ,biscayan ,medusae1 ,trans4 ,linn4 ,soc4 x4 7#aijf71 pp4 #afc-ahg1 pl4 xiii42 #h4 ,medusae in ,herdman1 ,rep4 ,pearl ,oyster ,fisheries1 ,gulf of ,manaar1 iv4 7#aije71 pp4 #aca-aff1 #d pls42 #i4 ,hydromedusae with a ,revision of the ,williadae and ,petasidae1 ,fauna and ,geogr4 ,maldive and ,laccadive ,archipelagos1 ii4 7#aijd71 pp4 #gbb-gdi1 pls4 liv4-lvii42 #aj4 ,on the ,freshwater ,medusa liberated by ,microhydra ryderi1 ,potts1 and a ,comparison with ,limnocodium1 ,quart4 ,journ4 ,micr4 ,sci4 ,i 7#aijf71 pp4 #fce1 #fde1 pl4 xxxvii42 #aj;a4 ,on the ,freshwater ,medusa ,limnocnida tanganicae ,budgett ,memorial ,volume 7,cambridge1 #aijh1 pp4 #dga-dhb1 pl4 xxviii42 #aa4 ,c4 ,claus1 ber die ,struktur der ,muskelzellen und ber den ,krperbau von ,mnestra parasites ,krohn1 ,verhandl4 zool4 bot4 ,ges4 ,wien1 xxv4 7#ahgf71 pp4 #i-ab1 pl4 i42 #aa;a4 ,c4 ,dawydov1 ,hydroctena salenskii1 ,mm4 ,acad4 ,imp4 ,st4 ,ptersbourg 7viii47 xiv4 ,no4 #i 7#aijc71 #ag pp41 #a pl42 #ab4 ,a4 ,dendy1 ,on a ,free-swimming ,hydroid1 ,pelagohydra mirabilis1 n4 gen4 et sp41 ,quart4 ,journ4 ,micr4 ,sci4 xlvi4 7#aijc71 pp4 #a-bd1 pls4 i4 ii42 #ac4 ,h4 ,driesch1 ,tektonische ,studien an ,hydroidpolypen1 7#a7 ,jen4 ,zeitschr41 xxiv4 7#ahij71 pp4 #ahi-bbf1 #ab figs42 7#b7 t4c4 pp4 #feg-fhh1 #f figs42 7#c7 ibid4 xxv4 7#ahia71 pp4 #dfg-dgi1 #c figs42 #ad4 ,g4 ,duplessis1 ,on ,campanularia volubilis1 ,soc4 ,vaud4 ,bull4 #ac 7,lausanne1 #ahgd-ahge72 #ae4 ,j4 ,w4 ,fewkes1 ,on ,mnestra1 ,amer4 ,natural41 xviii4 7#ahhd71 pp4 #aig-aih1 #c figs42 #af4 ,s4 ,goto1 ,dendrocoryne ,inaba1 ,vertreterin einer neuen ,familie der ,hydromedusen1 ,annot4 ,zool4 ,tokyo1 i4 7#ahig71 pp4 #ic-ajd1 pl4 vi41 figs4 #ajf-aac2 #ag4 ,the ,craspe dote ,medusa ,olindias and some of its ,natural ,allies1 ,mark ,anniversary ,volume 7,new ,york1 #aijc71 pp4 #a-bb1 #c pls42 #ah4 ,h4 ,grenacher1 ber die ,nesselkapseln von ,hydra1 ,zool4 ,anz4 xviii4 7#ahie71 pp4 #caj-cba1 #g figs42 #ai4 ,r4 ,t4 ,gnther1 ,on the ,structure and ,affinities of ,mnestra parasites ,krohn2 with a revision of the ,classification of the ,cladonemidae1 ,mitt4 ,stat4 ,neapel1 xvi4 7#aijc71 pp4 #ce-fb1 pls4 ii4 iii42 #bj4 ,e4 ,haeckel1 ,das ,system der ,medusen1 ,denkschr4 med4-nat4-wiss4 ,ges4 7,jena1 #ahgi-ahha72 #ba4 ,deep ,sea ,medusae1 in ,reports of the ,challenger ,expedition1 ,zool4 iv4 pt4 #b 7,london1 #ahhb72 #bb4 ,p4 ,hallez1 ,bougainvillia fruticosa ,allm4 est le facis d'eau agite du ,bougainvillia ramosa ,van ,ben4 ,c4-,r4 ,acad4 ,sci4 ,paris1 cxl4 7#aije71 pp4 #deg-dei2 #bc4 ,o4 ,r4 ,hertwig1 ,der ,organismus der ,medusen 7,jena1 #ahgh71 #gj pp41 #c pls42 #bd4 ,das ,nervensystem und die ,sinnesorgane der ,medusen 7,leipzig1 #ahgh71 #ahf pp41 #aj pls42 #be4 ,s4 ,j4 ,hickson1 ,the ,medusae of ,millepora1 ,proc4 ,roy4 ,soc4 lxvi4 7#ahii71 pp4 #f-aj1 #aj figs42 #bf4 ,t4 ,hincks1 ,a ,history of ,british ,hydroid ,zoophytes 7#b vols41 ,london1 #ahfh72 #bg4 ,n4 ,iwanzov1 ber den ,bau1 die ,wirkungsweise und die ,entwickelung der ,nesselkapseln von ,coelenteraten1 ,bull4 ,soc4 ,imp4 ,natural1 ,moscou 7#ahif71 pp4 #cbc-cee1 #d pls42 #bh4 ,c4 ,f4 ,jickeli1 ,der ,bau der ,hydroidpolypen1 7#a7 ,morph4 ,jahrbuch1 viii4 7#ahhc71 pp4 #cgc-daf1 pls4 xvi4-xviii42 7#b7 t4c41 pp4 #ehj-fhj1 pls4 xxv4-xxviii42 #bi4 ,albert ,lang1 ber die ,knospung bei ,hydra und einigen ,hydropolypen1 ,zeitschr4 f4 wiss4 ,zool4 liv4 7#ahib71 pp4 #cfe-chd1 pl4 xvii42 #cj4 ,arnold ,lang1 ,gastroblasta ,raffaelei4 ,eine durch eine ,art unvollstndiger ,theilung entstehende ,medusen-,kolonie1 ,jena ,zeitschr4 xix4 7#ahhf71 pp4 #gce-gfb1 pls4 xx41 xxi42 #ca4 ,a4 ,linko1 ,observations sur les mduses de la mer ,blanche1 ,trav4 ,soc4 ,imp4 ,nat4 ,st ,ptersbourg1 xxix4 7#ahii72 #cb4 ber den ,bau der ,augen bei den ,hydromedusen1 ,zapiski ,imp4 ,akad4 ,nauk 7,mm4 ,acad4 ,imp4 ,sci47 ,st ,ptersbourg 7#h7 x4 #c 7#aijj71 #bc pp41 #b pls42 #cc4 ,o4 ,maas1 ,die craspedoten ,medusen1 in ,ergebn4 ,plankton ,expedition1 ii4 7,kiel and ,leipzig1 #ahic71 #ajg pp41 #h pls41 #c figs42 #cd4 ,die ,medusen1 ,mem4 ,mus4 ,comp4 ,zool4 ,harvard1 xxiii4 7#ahig71 i42 #ce4 ,on ,hydroctena1 ,zool4 ,centralbl4 xi4 7#aijd71 pp4 #bdj-bdc2 #cf4 ,revision des mduses appartenant aux familles des ,cunanthidae et des ,aeginidae1 et groupement nouveau des genres1 ,bull4 ,mus4 ,monaco1 v4 7#aijd71 #h pp42 #cg4 ,revision der ,cannotiden ,haeckels1 ,,sb4 ,k4 ,bayer4 ,akad4 xxxiv4 7#aijd71 pp4 #dba-dde2 #ch4 ,meduses1 ,result4 ,camp4 ,sci4 ,monaco1 xxviii4 7#aijd71 #ga pp41 #f pls42 #ci4 ,die craspedoten ,medusen der ,siboga-,expedition1 ,uitkomst4 ,siboga-,exped4 x4 7#aije71 #hd pp41 #ad pls42 #dj4 ,die arktischen ,medusen 7ausschliesslich der ,polypomedusen71 ,fauna arctica1 iv4 7#aijf71 pp4 #dgi-ebf2 #da4 ,c4 ,mereschkowsky1 ,on a new ,genus of ,hydroids 7,monobrachium7 from the ,white ,sea1 with a short description of other new ,hydroids1 ,ann4 ,mag4 ,nat4 ,hist4 7#d7 xx4 7#ahgg71 pp4 #bbj-bbi1 pls4 v4 vi42 #db4 ,e4 ,metchinkoft1 ,studien ber die ,entwickelung der ,medusen und ,siphonophoren1 ,zeitschr4 f4 wiss4 ,zool4 xxiv4 7#ahgd71 pp4 #ae-hc1 pls4 i4-xii42 #dc4 ,vergleichend-embryologische ,studien 7,geryoniden1 ,cunina71 ibid4 xxxvi4 7#ahhb71 pp4 #dcc-deh1 pl4 xxviii42 #dd4 ,embryologische ,studien an ,medusen 7,vienna1 #ahhf71 #aej pp41 #ab pls41 #aj figs42 #de4 ,medusologische ,mittheilungen1 ,arb4 zool4 ,inst4 ,wien1 vi4 7#ahhf71 pp4 #bcg-bff1 pls4 xxii4 xxiii42 #df4 ,l4 ,murbach1 ,beitrge zur ,kenntnis der ,anatomie und ,entwickelung der ,nesselorgane der ,hydroiden1 ,arch4 f4 ,naturgesch4 lx4 i4 7#ahid71 pp4 #bag-bed1 pl4 xii42 #dg4 ,preliminary ,note on the ,life-,history of ,gonionemus1 ,journ4 ,morph4 xi4 7#ahie71 pp4 #dic-dif2 #dh4 ,l4 ,murbach and ,c4 ,shearer1 ,on ,medusae from the ,coast of ,british ,columbia and ,alaska1 ,proc4 ,zool4 ,soc4 7#aijc71 ii4 pp4 #afd-aia1 pls4 xvii4-xxii42 #di4 ,h4 ,f4 ,perkins1 ,the ,development of ,gonionema murbachii1 ,proc4 ,acad4 ,nat4 ,sci4 ,philadelphia 7#aijb71 pp4 #gej-gij1 pls4 xxxi-xxxiv42 #ej4 ,f4 ,schaudinn1 ber ,haleremita cumulans1 n4 g4 n4 sp41 einen marinen ,hydroidpolypen1 ,,sb4 ,ges4 natforsch4 ,freunde ,berlin 7#ahid71 pp4 #bbf-bcd1 #h figs42 #ea4 ,f4 ,e4 ,schulze1 ,on the ,structure and ,arrangement of the ,soft ,parts in ,euplectella aspergillum 7,amphibrachium71 ,tr4 ,r4 ,soc4 ,edinburgh1 xxix4 7#ahhj71 pp4 #ffa-fgc1 pl4 xvii42 #eb4 ,o4 ,seeliger1 ber das ,verhalten der ,keimbltter bei der ,knospung der ,clenteraten1 ,zeitschr4 f4 wiss4 ,zool4 lviii4 7#ahid71 pp4 #aeb-ahh1 pls4 vii4-ix42 #ec4 ,w4 ,b4 ,spencer1 ,a new ,family of ,hydroidea 7,clathrozoon71 together with a description of the ,structure of a new ,species of ,plumularia1 ,trans4 ,roy4 ,soc4 ,victoria 7#ahij71 pp4 #aba-adj1 #g pls42 #ed4 ,m4 ,ussow1 ,a new ,form of ,fresh-water ,coelenterate 7,polypodium71 ,ann4 ,mag4 ,nat4 ,hist4 7#e7 xviii4 7#ahhf71 pp4 #aaj-abd1 pl4 iv42 #ee4 ,e4 ,vanhffen1 ,versuch einer natrlichen ,gruppierung der ,anthomedusen1 ,zool4 ,anzeiger1 xiv4 7#ahia71 pp4 #dci-ddf2 #ef4 ,c4 ,viguier1 tudes sur les animaux infrieurs de la baie d',alger 7,tetraplatia71 ,arch4 ,zool4 ,exp4 ,gen4 viii4 7#ahij71 pp4 #aja-adb1 pls4 vii4-ix42 #eg4 ,j4 ,wagner1 ,recherches sur l'organisation de ,monobrachium parasiticum ,mrjk1 ,arch4 biol4 x4 7#ahij71 pp4 #bgc-cji1 pls4 viii4 ix42 #eh4 ,a4 ,weismann1 ,die ,entstehung der ,sexualzellen bei den ,hydromedusen 7,jena1 #ahhc72 #ei4 ,r4 ,woltereck1 ,beitrge zur ,ontogenie und ,ableitung des ,siphonophorenstocks1 ,zeitschr4 f4 wiss4 ,zool4 lxxxii4 7#aije71 pp4 #faa-fcg1 #ba text-figs42 #fj4 ,j4 ,wulfert1 ,die ,embryonalentwickelung von ,gonothyraea loveni ,allm41 ,zeitschr4 f4 wiss4 ,zool4 lxxi4 7#aijb71 pp4 #bif-cbf1 pls4 xvi4-xviii4 7,e4 ,a4 ,m47 ,,footnotes3 #a ,in some cases hydroids have been reared in aquaria from ova of medusae1 but these hydroids have not yet been found in the sea 7,browne #aj a74 #b ,the numbers in square brackets refer to the bibliography at the end of this article2 but when the number is preceded by the word ,hydrozoa1 it refers to the bibliography at the end of the article ,,hydrozoa4 ,,hydrometer 7,gr4 ,greek3 hydr1 water1 and ,greek3 metron1 a measure71 an instrument for determining the density of bodies1 generally of fluids1 but in some cases of solids4 ,when a body floats in a fluid under the action of gravity1 the weight of the body is equal to that of the fluid which it displaces 7see ,,hydromechanics74 ,it is upon this principle that the hydrometer is constructed1 and it obviously admits of two modes of application in the case of fluids3 either we may compare the weights of floating bodies which are capable of displacing the same volume of different fluids1 or we may compare the volumes of the different fluids which are displaced by the same weight4 ,in the latter case1 the densities of the fluids will be inversely proportional to the volumes thus displaced4 ,the hydrometer is said by ,synesius ,cyreneus in his fifth letter to have been invented by ,hypatia at ,alexandria1#a but appears to have been neglected until it was reinvented by ,robert ,boyle1 whose ,new ,essay ,instrument1 as described in the ,phil4 ,trans4 for ,june #afge1 differs in no essential particular from ,nicholson's hydrometer4 ,this instrument was devised for the purpose of detecting counterfeit coin1 especially guineas and half-guineas4 ,in the first section of the paper 7,phil4 ,trans4 ,no4 #aae1 p4 #cbi7 the author refers to a glass instrument exhibited by himself many years before1 and consisting of a bubble furnished with a long and slender stem1 which was to be put into several liquors1 to compare and estimate their specific gravities4 ,this seems to be the first reference to the hydrometer in modern times4 ,in fig4 #a ,c represents the instrument used for guineas1 the circular plates ,a representing plates of lead1 which are used as ballast when lighter coins than guineas are examined4 ,b represents a small glass instrument for estimating the specific gravities of liquors1 an account of which was promised by ,boyle in the following number of the ,phil4 ,trans41 but did not appear4 ,illustration3 ,,fig4 #a4--;,boyle's ,new ,essay ,instrument4 ,the instrument represented at ,b 7fig4 #a71 which is copied from ,robert ,boyle's sketch in the ,phil4 ,trans4 for #afge1 is generally known as the common hydrometer4 ,it is usually made of glass1 the lower bulb being loaded with mercury or small shot which serves as ballast1 causing the instrument to float with the stem vertical4 ,the quantity of mercury or shot inserted depends upon the density of the liquids for which the hydrometer is to be employed1 it being essential that the whole of the bulb should be immersed in the heaviest liquid for which the instrument is used1 while the length and diameter of the stem must be such that the hydrometer will float in the lightest liquid for which it is required4 ,the stem is usually divided into a number of equal parts1 the divisions of the scale being varied in different instruments1 according to the purposes for which they are employed4 ,let ,v denote the volume of the instrument immersed 7i4e4 of liquid displaced7 when the surface of the liquid in which the hydrometer floats coincides with the lowest division of the scale1 ,a the area of the transverse section of the stem1 l the length of a scale division1 n the number of divisions on the stem1 and ,w the weight of the instrument4 ,suppose the successive divisions of the scale to be numbered #j1 #a1 #b 444 n starting with the lowest1 and let w#j1 ,w#a1 w#b 444 wn be the weights of unit volume of the liquids in which the hydrometer sinks to the divisions #j1 #a1 #b 444 n respectively4 ,then1 by the principle of ,archimedes1 ,w ,vw#j2 or w#j ,w_/,v4 ,also ,w 7,v l,a7w#a2 or w#a ,w_/7,v l,a71 wp ,w_/7,v pl,a71 and wn ,w_/7,v nl,a71 or the densities of the several liquids vary inversely as the respective volumes of the instrument immersed in them2 and1 since the divisions of the scale correspond to equal increments of volume immersed1 it follows that the densities of the several liquids in which the instrument sinks to the successive divisions form a harmonic series4 ,if ,v ,nl,a then ,n expresses the ratio of the volume of the instrument up to the zero of the scale to that of one of the scale-divisions4 ,if we suppose the lower part of the instrument replaced by a uniform bar of the same sectional area as the stem and of volume ,v1 the indications of the instrument will be in no respect altered1 and the bottom of the bar will be at a distance of ,n scale-divisions below the zero of the scale4 ,in this case we have wp ,w_/7,n p7l,a2 or the density of the liquid varies inversely as ,n p1 that is1 as the whole number of scale-divisions between the bottom of the tube and the plane of flotation4 ,if we wish the successive divisions of the scale to correspond to equal increments in the density of the corresponding liquids1 then the volumes of the instrument1 measured up to the successive divisions of the scale1 must form a series in harmonical progression1 the lengths of the divisions increasing as we go up the stem4 ,the greatest density of the liquid for which the instrument described above can be employed is ,w_/,v1 while the least density is ,w_/7,v nl,a71 or ,w_/7,v v71 where v represents the volume of the stem between the extreme divisions of the scale4 ,now1 by increasing v1 leaving ,w and ,v unchanged1 we may increase the range of the instrument indefinitely4 ,but it is clear that if we increase ,a1 the sectional area of the stem1 we shall diminish l1 the length of a scale-division corresponding to a given variation of density1 and thereby proportionately diminish the sensibility of the instrument1 while diminishing the section ,a will increase l and proportionately increase the sensibility1 but will diminish the range over which the instrument can be employed1 unless we increase the length of the stem in the inverse ratio of the sectional area4 ,hence1 to obtain great sensibility along with a considerable range1 we require very long slender stems1 and to these two objections apply in addition to the question of portability2 for1 in the first place1 an instrument with a very long stem requires a very deep vessel of liquid for its complete immersion1 and1 in the second place1 when most of the stem is above the plane of flotation1 the stability of the instrument when floating will be diminished or destroyed4 ,the various devices which have been adopted to overcome this difficulty will be described in the account given of the several hydrometers which have been hitherto generally employed4 ,the plan commonly adopted to obviate the necessity of inconveniently long stems is to construct a number of hydrometers as nearly alike as may be1 but to load them differently1 so that the scale-divisions at the bottom of the stem of one hydrometer just overlap those at the top of the stem of the preceding4 ,by this means a set of six hydrometers1 each having a stem rather more than #e in4 long1 will be equivalent to a single hydrometer with a stem of #cj in4 ,but1 instead of employing a number of instruments differing only in the weights with which they are loaded1 we may employ the same instrument1 and alter its weight either by adding mercury or shot to the interior 7if it can be opened7 or by attaching weights to the exterior4 ,these two operations are not quite equivalent1 since a weight added to the interior does not affect the volume of liquid displaced when the instrument is immersed up to a given division of the scale1 while the addition of weights to the exterior increases the displacement4 ,this difficulty may be met1 as in ,keene's hydrometer1 by having all the weights of precisely the same volume but of different masses1 and never using the instrument except with one of these weights attached4 ,illustration3 ,,fig4 #b4--;,clarke's ,hydrometer4 ,the first hydrometer intended for the determination of the densities of liquids1 and furnished with a set of weights to be attached when necessary1 was that constructed by ,mr ,clarke 7instrument-maker7 and described by ,j4 ,t4 ,desaguliers in the ,philosophical ,transactions for ,march and ,april #agcj1 ,no4 #dac1 p4 #bgh4 ,the following is ,desaguliers's account of the instrument 7fig4 #b73-- ,after having made several fruitless trials with ivory1 because it imbibes spirituous liquors1 and thereby alters its gravity1 he 7,mr ,clarke7 at last made a copper hydrometer1 represented in fig4 #b1 having a brass wire of about #a in4 thick going through1 and soldered into the copper ball ,bb4 ,the upper part of this wire is filed flat on one side1 for the stem of the hydrometer1 with a mark at m1 to which it sinks exactly in proof spirits4 ,there are two other marks1 ,a and ,b1 at top and bottom of the stem1 to show whether the liquor be 7#a_/aj7th above proof 7as when it sinks to ,a71 or 7#a_/aj7th under proof 7as when it emerges to ,b71 when a brass weight such as ,c has been screwed on to the bottom at c4 ,there are a great many such weights1 of different sizes1 and marked to be screwed on instead of ,c1 for liquors that differ more than 7#a_/aj7th from proof1 so as to serve for the specific gravities in all such proportions as relate to the mixture of spirituous liquors1 in all the variety made use of in trade4 ,there are also other balls for showing the specific gravities quite to common water1 which make the instrument perfect in its kind4 ,clarke's hydrometer1 as afterwards constructed for the purposes of the excise1 was provided with thirty-two weights to adapt it to spirits of different specific gravities1 and eleven smaller weights1 or weather weights as they were called1 which were attached to the instrument in order to correct for variations of temperature4 ,the weights were adjusted for successive intervals of #e ,f41 but for degrees intermediate between these no additional correction was applied4 ,the correction for temperature thus afforded was not sufficiently accurate for excise purposes1 and ,william ,speer in his essay on the hydrometer 7,tilloch's ,phil4 ,mag41 #ahjb1 vol4 xiv47 mentions cases in which this imperfect compensation led to the extra duty payable upon spirits which were more than #aj over proof being demanded on spirits which were purposely diluted to below #aj over proof in order to avoid the charge4 ,clarke's hydrometer1 however1 remained the standard instrument for excise purposes from #aghg until it was displaced by that of ,sikes4 ,desaguliers himself constructed a hydrometer of the ordinary type for comparing the specific gravities of different kinds of water 7,desaguliers's ,experimental ,philosophy1 ii4 #bcd74 ,in order to give great sensibility to the instrument1 the large glass ball was made nearly #c in4 in diameter1 while the stem consisted of a wire #aj in4 in length and only 7#a_/dj7;in4 in diameter4 ,the instrument weighed #djjj grains1 and the addition of a grain caused it to sink through an inch4 ,by altering the quantity of shot in the small balls the instrument could be adapted for liquids other than water4 ,to an instrument constructed for the same purpose1 but on a still larger scale than that of ,desaguliers1 ,a4 ,deparcieux added a small dish on the top of the stem for the reception of the weights necessary to sink the instrument to a convenient depth4 ,the effect of weights placed in such a dish or pan is of course the same as if they were placed within the bulb of the instrument1 since they do not alter the volume of that part which is immersed4 ,illustration3 ,,fig4 #c4--,nicholson's ,hydrometer4 ,the first important improvement in the hydrometer after its reinvention by ,boyle was introduced by ,g4 ,d4 ,fahrenheit1 who adopted the second mode of construction above referred to1 arranging his instrument so as always to displace the same volume of liquid1 its weight being varied accordingly4 ,instead of a scale1 only a single mark is placed upon the stem1 which is very slender1 and bears at the top a small scale pan into which weights are placed until the instrument sinks to the mark upon its stem4 ,the volume of the displaced liquid being then always the same1 its density will be proportional to the whole weight supported1 that is1 to the weight of the instrument together with the weights required to be placed in the scale pan4 ,nicholson's hydrometer 7fig4 #c7 combines the characteristics of ,fahrenheit's hydrometer and of ,boyle's essay instrument4#b ,the following is the description given of it by ,w4 ,nicholson in the ,manchester ,memoirs1 ii4 #cgd3-- ,,aa represents a small scale4 ,it may be taken off at ,d4 ,diameter #a in41 weight #dd grains4 ,b a stem of hardened steel wire4 ,diameter #a_/ajj in4 ,e a hollow copper globe4 ,diameter #b7h_/aj7 in4 ,weight with stem #cfi grains4 ,,ff a stirrup of wire screwed to the globe at ,c4 ,g a small scale1 serving likewise as a counterpoise4 ,diameter #a in4 ,weight with stirrup #afcd grains4 ,the other dimensions may be had from the drawing1 which is one-sixth of the linear magnitude of the instrument itself4 ,in the construction it is assumed that the upper scale shall constantly carry #ajjj grains when the lower scale is empty1 and the instrument sunk in distilled water at the temperature of #fj ,fahr4 to the middle of the wire or stem4 ,the length of the stem is arbitrary1 as is likewise the distance of the lower scale from the surface of the globe4 ,but1 the length of the stem being settled1 the lower scale may be made lighter1 and1 consequently1 the globe less1 the greater its distance is taken from the surface of the globe2 and the contrary4 ,in comparing the densities of different liquids1 it is clear that this instrument is precisely equivalent to that of ,fahrenheit1 and must be employed in the same manner1 weights being placed in the top scale only until the hydrometer sinks to the mark on the wire1 when the specific gravity of the liquid will be proportional to the weight of the instrument together with the weights in the scale4 ,in the subsequent portion of the paper above referred to1 ,nicholson explains how the instrument may be employed as a thermometer1 since1 fluids generally expanding more than the solids of which the instrument is constructed1 the instrument will sink as the temperature rises4 ,to determine the density of solids heavier than water with this instrument1 let the solid be placed in the upper scale pan1 and let the weight now required to cause the instrument to sink in distilled water at standard temperature to the mark ,b be denoted by w1 while ,w denotes the weight required when the solid is not present4 ,then ,w - w is the weight of the solid4 ,now let the solid be placed in the lower pan1 care being taken that no bubbles of air remain attached to it1 and let w#a be the weight now required in the scale pan4 ,this weight will exceed w in consequence of the water displaced by the solid1 and the weight of the water thus displaced will be ,w#a - w1 which is therefore the weight of a volume of water equal to that of the solid4 ,hence1 since the weight of the solid itself is ,w - w1 its density must be 7,w - w7_/7w#a - w74 ,the above example illustrates how ,nicholson's or ,fahrenheit's hydrometer may be employed as a weighing machine for small weights4 ,in all hydrometers in which a part only of the instrument is immersed1 there is a liability to error in consequence of the surface tension1 or capillary action1 as it is frequently called1 along the line of contact of the instrument and the surface of the liquid 7see ,,capillary ,,action74 ,this error diminishes as the diameter of the stem is reduced1 but is sensible in the case of the thinnest stem which can be employed1 and is the chief source of error in the employment of ,nicholson's hydrometer1 which otherwise would be an instrument of extreme delicacy and precision4 ,the following is ,nicholson's statement on this point3-- ,one of the greatest difficulties which attends hydrostatical experiments arises from the attraction or repulsion that obtains at the surface of the water4 ,after trying many experiments to obviate the irregularities arising from this cause1 ,i find reason to prefer the simple one of carefully wiping the whole instrument1 and especially the stem1 with a clean cloth4 ,the weights in the dish must not be esteemed accurate while there is either a cumulus or a cavity in the water round the stem4 ,it is possible by applying a little oil to the upper part of the bulb of a common or of a ,sikes's hydrometer1 and carefully placing it in pure water1 to cause it to float with the upper part of the bulb and the whole of the stem emerging as indicated in fig4 #d1 when it ought properly to sink almost to the top of the stem1 the surface tension of the water around the circumference of the circle of contact1 ,,aa'1 providing the additional support required4 ,illustration3 ,,fig4 #d4 ,the universal hydrometer of ,g4 ,atkins1 described in the ,phil4 ,mag4 for #ahjh1 xxxi4 #bed1 is merely ,nicholson's hydrometer with the screw at ,c projecting through the collar into which it is screwed1 and terminating in a sharp point above the cup ,g4 ,to this point soft bodies lighter than water 7which would float if placed in the cup7 could be attached1 and thus completely immersed4 ,atkins's instrument was constructed so as to weigh #gjj grains1 and when immersed to the mark on the stem in distilled water at #fj ,f4 it carried #cjj grains in the upper dish4 ,the hydrometer therefore displaced #ajjj grains of distilled water at #fj ,f4 and hence the specific gravity of any other liquid was at once indicated by adding #gjj to the number of grains in the pan required to make the instrument sink to the mark on the stem4 ,the small divisions on the scale corresponded to differences of 7#a_/aj7th of a grain in the weight of the instrument4 ,the ,gravimeter1 constructed by ,citizen ,guyton and described in ,nicholson's ,journal1 #dto1 i4 #aaj1 differs from ,nicholson's instrument in being constructed of glass1 and having a cylindrical bulb about #ba centimetres in length and #bb millimetres in diameter4 ,its weight is so adjusted that an additional weight of #e grammes must be placed in the upper pan to cause the instrument to sink to the mark on the stem in distilled water at the standard temperature4 ,the instrument is provided with an additional piece1 or plongeur1 the weight of which exceeds #e grammes by the weight of water which it displaces2 that is to say1 it is so constructed as to weigh #e grammes in water1 and consists of a glass envelope filled with mercury4 ,it is clear that the effect of this plongeur1 when placed in the lower pan1 is exactly the same as that of the #e gramme weight in the upper pan4 ,without the extra #e grammes the instrument weighs about #bj grammes1 and therefore floats in a liquid of specific gravity 4#h4 ,thus deprived of its additional weight it may be used for spirits4 ,to use the instrument for liquids of much greater density than water additional weights must be placed in the upper pan1 and the plongeur is then placed in the lower pan for the purpose of giving to the instrument the requisite stability4 ,charles's balance areometer is similar to ,nicholson's hydrometer1 except that the lower basin admits of inversion1 thus enabling the instrument to be employed for solids lighter than water1 the inverted basin serving the same purpose as the pointed screw in ,atkins's modification of the instrument4 ,adie's sliding hydrometer is of the ordinary form1 but can be adjusted for liquids of widely differing specific gravities by drawing out a sliding tube1 thus changing the volume of the hydrometer while its weight remains constant4 ,the hydrometer of ,a4 ,baum1 which has been extensively used in ,france1 consists of a common hydrometer graduated in the following manner4 ,certain fixed points were first determined upon the stem of the instrument4 ,the first of these was found by immersing the hydrometer in pure water1 and marking the stem at the level of the surface4 ,this formed the zero of the scale4 ,fifteen standard solutions of pure common salt in water were then prepared1 containing respectively #a1 #b1 #c1 444 #ae 7by weight7 of dry salt4 ,the hydrometer was plunged in these solutions in order1 and the stem having been marked at the several surfaces1 the degrees so obtained were numbered #a1 #b1 #c1 444 #ae4 ,these degrees were1 when necessary1 repeated along the stem by the employment of a pair of compasses till #hj degrees were marked off4 ,the instrument thus adapted to the determination of densities exceeding that of water was called the hydrometer for salts4 ,the hydrometer intended for densities less than that of water1 or the hydrometer for spirits1 is constructed on a similar principle4 ,the instrument is so arranged that it floats in pure water with most of the stem above the surface4 ,a solution containing #aj of pure salt is used to indicate the zero of the scale1 and the point at which the instrument floats when immersed in distilled water at #aj ,r4 7#ed ,f47 is numbered #aj4 ,equal divisions are then marked off upwards along the stem as far as the #ejth degree4 ,the densities corresponding to the several degrees of ,baum's hydrometer are given by ,nicholson 7,journal of ,philosophy1 i4 #hi7 as follows3-- ,baum's ,hydrometer for ,spirits4 ,temperature #aj ,r4 ---------------------------------------- -------- ,degrees4,density4,degrees4,density4,deg rees4,density4 ---------------------------------------- -------- #aj #a4jjj #ba 4#ibb #ca 4#hfa #aa 4#iij #bb 4#iae #cb 4#hef #ab 4#ihe #bc 4#iji #cc 4#heb #ac 4#igg #bd 4#ijc #cd 4#hdg #ad 4#igj #be 4#hig #ce 4#hdb #ae 4#ifc #bf 4#hib #cf 4#hcg #af 4#iee #bg 4#hhf #cg 4#hcb #ag 4#idi #bh 4#hhj #ch 4#hbg #ah 4#idc #bi 4#hgd #ci 4#hbb #ai 4#ice #cj 4#hfg #dj 4#hag #bj 4#ibh ---------------------------------------- -------- ,baume's ,hydrometer for ,salts4 ---------------------------------------- -------- ,degrees4,density4,degrees4,density4,deg rees4,density4 ---------------------------------------- -------- #j #a4jjj #bg #a4bcj #ea #a4edg #c #a4jbj #cj #a4bfa #ed #a4eid #f #a4jdj #cc #a4bie #eg #a4fei #i #a4jfd #cf #a4ccc #fj #a4gag #ab #a4jhi #ci #a4cgc #fc #a4ggi #ae #a4aad #db #a4dad #ff #a4hdh #ah #a4adj #de #a4dee #fi #a4ibj #ba #a4agj #dh #a4ejj #gb #b4jjj #bd #a4bjj ---------------------------------------- -------- ,carrier's hydrometer was very similar to that of ,baum1 ,cartier having been employed by the latter to construct his instruments for the ,french revenue4 ,the point at which the instrument floated in distilled water was marked #aj by ,cartier1 and #cj on ,carrier's scale corresponded to #cb on ,baum's4 ,perhaps the main object for which hydrometers have been constructed is the determination of the value of spirituous liquors1 chiefly for revenue purposes4 ,to this end an immense variety of hydrometers have been devised1 differing mainly in the character of their scales4 ,in ,speer's hydrometer the stem has the form of an octagonal prism1 and upon each of the eight faces a scale is engraved1 indicating the percentage strength of the spirit corresponding to the several divisions of the scale1 the eight scales being adapted respectively to the temperature #ce1 #dj1 #de1 #ej1 #ee1 #fj1 #fe and #gj ,f4 ,four small pins1 which can be inserted into the counterpoise of the instrument1 serve to adapt the instrument to the temperatures intermediate between those for which the scales are constructed4 ,william ,speer was supervisor and chief assayer of spirits in the port of ,dublin4 ,for a more complete account of this instrument see ,tilloch's ,phil4 ,mag41 xiv4 #aea4 ,illustration3 ,,fig4 #e4--;,jones's ,hydrometer4 ,the hydrometer constructed by ,jones1 of ,holborn1 consists of a spheroidal bulb with a rectangular stem 7fig4 #e74 ,between the bulb and counterpoise is placed a thermometer1 which serves to indicate the temperature of the liquid1 and the instrument is provided with three weights which can be attached to the top of the stem4 ,on the four sides of the stem ,,ad are engraved four scales corresponding respectively to the unloaded instrument1 and to the instrument loaded with the respective weights4 ,the instrument when unloaded serves for the range from #gd to #dg over proof2 when loaded with the first weight it indicates from #df to #ac over proof1 with the second weight from #ac over proof to #bi under proof1 and with the third from #bi under proof to pure water1 the graduation corresponding to which is marked ,w at the bottom of the fourth scale4 ,one side of the stem ,,ad is shown in fig4 #e1 the other three in fig4 #f4 ,the thermometer is also provided with four scales corresponding to the scales above mentioned4 ,each scale has its zero in the middle corresponding to #fj ,f4 ,if the mercury in the thermometer stand above this zero the spirit must be reckoned weaker than the hydrometer indicates by the number on the thermometer scale level with the top of the mercury1 while if the thermometer indicate a temperature lower than the zero of the scale 7#fj ,f47 the spirit must be reckoned stronger by the scale reading4 ,at the side of each of the four scales on the stem of the hydrometer is engraved a set of small numbers indicating the contraction in volume which would be experienced if the requisite amount of water 7or spirit7 were added to bring the sample tested to the proof strength4 ,illustration3 ,,fig4 #f4 ,the hydrometer constructed by ,dicas of ,liverpool is provided with a sliding scale which can be adjusted for different temperatures1 and which also indicates the contraction in volume incident on bringing the spirit to proof strength4 ,it is provided with thirty-six different weights which1 with the ten divisions on the stem1 form a scale from #j to #cgj4 ,the employment of so many weights renders the instrument ill-adapted for practical work where speed is an object4 ,illustration3 ,,fig4 #g4--;,atkins's ,hydrometer4 ,this instrument was adopted by the ,united ,states in #agij1 but was subsequently discarded by the ,internal ,revenue ,service for another type4 ,in this latter form the observations have to be made at the standard temperature of #fj ,f41 at which the graduation #ajj corresponds to proof spirit and #bjj to absolute alcohol4 ,the need of adjustable weights is avoided by employing a set of five instruments1 graduated respectively #j-ajj1 #hj-abj1 #ajj-adj1 #acj-agj1 #afj-bjj4 ,the reading gives the volume of proof spirit equivalent to the volume of liquor2 thus the readings #hj and #abj mean that #ajj volumes of the test liquors contain the same amount of absolute alcohol as #hj and #abj volumes of proof spirit respectively4 ,proof spirit is defined in the ,united ,states as a mixture of alcohol and water which contains equal volumes of alcohol and water at #fj ,f41 the alcohol having a specific gravity of #j4gici at #fj as compared with water at its maximum density4 ,the specific gravity of proof spirit is #j4iccec at #fj2 and #ajj volumes of the mixture is made from #ej volumes of absolute alcohol and #ec4ga volumes of water4 ,quin's universal hydrometer is described in the ,transactions of the ,society of ,arts1 viii4 #ih4 ,it is provided with a sliding rule to adapt it to different temperatures1 and has four scales1 one of which is graduated for spirits and the other three serve to show the strengths of worts4 ,the peculiarity of the instrument consists in the pyramidal form given to the stem1 which renders the scale-divisions more nearly equal in length than they would be on a prismatic stem4 ,atkins's hydrometer1 as originally constructed1 is described in ,nicholson's ,journal1 #hvo1 ii4 #bgf4 ,it is made of brass1 and is provided with a spheroidal bulb the axis of which is #b in4 in length1 the conjugate diameter being #a in4 ,the whole length of the instrument is #h in41 the stem square of about #a_/h-;in4 side1 and the weight about #djj grains4 ,it is provided with four weights1 marked #a1 #b1 #c1 #d1 and weighing respectively #bj1 #dj1 #fa and #hd grains1 which can be attached to the shank of the instrument at ,c 7fig4 #g7 and retained there by the fixed weight ,b4 ,the scale engraved upon one face of the stem contains fifty-five divisions1 the top and bottom being marked #j or zero and the alternate intermediate divisions 7of which there are twenty-six7 being marked with the letters of the alphabet in order4 ,the four weights are so adjusted that1 if the instrument floats with the stem emerging as far as the lower division #j with one of the weights attached1 then replacing the weight by the next heavier causes the instrument to sink through the whole length of the scale to the upper division #j1 and the first weight produces the same effect when applied to the naked instrument4 ,the stem is thus virtually extended to five times its length1 and the number of divisions increased practically to #bgb4 ,when no weight is attached the instrument indicates densities from 4#hjf to 4#hdc2 with ,no4 #a it registers from 4#hdc to 4#hhj1 with ,no4 #b from 4#hhj to 4#iah1 with ,no4 #c from 4#iah to 4#ieh1 and with ,no4 #d from 4#ieh to #a4jjj1 the temperature being #ee ,f4 ,it will thus be seen that the whole length of the stem corresponds to a difference of density of about 4#jd1 and one division to about 4#jjjgd1 indicating a difference of little more than #a_/c in the strength of any sample of spirits4 ,the instrument is provided with a sliding rule1 with scales corresponding to the several weights1 which indicate the specific gravity corresponding to the several divisions of the hydrometer scale compared with water at #ee ,f4 ,the slider upon the rule serves to adjust the scale for different temperatures1 and then indicates the strength of the spirit in percentages over or under proof4 ,the slider is also provided with scales1 marked respectively ,dicas and ,clarke1 which serve to show the readings which would have been obtained had the instruments of those makers been employed4 ,the line on the scale marked concentration indicates the diminution in volume consequent upon reducing the sample to proof strength 7if it is over proof1 ,o4,p47 or upon reducing proof spirit to the strength of the sample 7if it is under proof1 ,u4,p474 ,by applying the several weights in succession in addition to ,no4 #d the instrument can be employed for liquids heavier than water2 and graduations on the other three sides of the stem1 together with an additional slide rule1 adapt the instrument for the determination of the strength of worts4 ,atkins subsequently modified the instrument 7,nicholson's ,journal1 #hvo1 iii4 #ej7 by constructing the different weights of different shapes1 viz4 circular1 square1 triangular and pentagonal1 instead of numbering them #a1 #b1 #c and #d respectively1 a figure of the weight being stamped on the sliding rule opposite to every letter in the series to which it belongs1 thus diminishing the probability of mistakes4 ,he also replaced the letters on the stem by the corresponding specific gravities referred to water as unity4 ,further information concerning these instruments and the state of hydrometry in #ahjc will be found in ,atkins's pamphlet ,on the ,relation between the ,specific ,gravities and the ,strength of ,spirituous ,liquors 7#ahjc72 or ,phil4 ,mag4 xvi4 #bf-cc1 #bje-bab1 #cje-cab2 xvii4 #bjd-baj and #cbi-cda4 ,in ,gay-,lussac's alcoholometer the scale is divided into #ajj parts corresponding to the presence of #a1 #b1 444 by volume of alcohol at #ae ,c41 the highest division of the scale corresponding to the purest alcohol he could obtain 7density 4#gidg7 and the lowest division corresponding to pure water4 ,a table provides the necessary corrections for other temperatures4 ,tralles's hydrometer differs from ,gay-,lussac's only in being graduated at #d ,c4 instead of #ae ,c41 and taking alcohol of density 4#gici at #ae4e ,c4 for pure alcohol instead of 4#gidg as taken by ,gay-,lussac 7,keene's ,handbook of ,hydrometry74 ,in ,beck's hydrometer the zero of the scale corresponds to density #a4jjj and the division #cj to density 4#hej1 and equal divisions on the scale are continued as far as is required in both directions4 ,illustration3 ,,fig4 #h4--,sike's ,hydrometer4 ,in the centesimal hydrometer of ,francoeur the volume of the stem between successive divisions of the scale is always 7#a_/ajj7th of the whole volume immersed when the instrument floats in water at #d ,c4 ,in order to graduate the stem the instrument is first weighed1 then immersed in distilled water at #d ,c41 and the line of flotation marked zero4 ,the first degree is then found by placing on the top of the stem a weight equal to 7#a_/ajj7th of the weight of the instrument1 which increases the volume immersed by 7#a_/ajj7th of the original volume4 ,the addition to the top of the stem of successive weights1 each 7#a_/ajj7th of the weight of the instrument itself1 serves to determine the successive degrees4 ,the length of #ajj divisions of the scale1 or the length of the uniform stem the volume of which would be equal to that of the hydrometer up to the zero graduation1 ,francoeur called the modulus of the hydrometer4 ,he constructed his instruments of glass1 using different instruments for different portions of the scale 7,francoeur1 ,trait d'aromtrie1 ,paris1 #ahdb74 ,dr ,boris of ,montpellier constructed a hydrometer which was based upon the results of his experiments on mixtures of alcohol and water4 ,the interval between the points corresponding to pure alcohol and to pure water ,boris divided into #ajj equal parts1 though the stem was prolonged so as to contain only #aj of these divisions1 the other #ij being provided for by the addition of #i weights to the bottom of the instrument as in ,clarke's hydrometer4 ,the instrument which has now been exclusively used for revenue purposes for nearly a century is that associated with the name of ,bartholomew ,sikes1 who was correspondent to the ,board of ,excise from #aggd to #aghc1 and for some time collector of excise for ,hertfordshire4 ,sikes's hydrometer1 on account of its similarity to that of ,boris1 appears to have been borrowed from that instrument4 ,it is made of gilded brass or silver1 and consists of a spherical ball ,a 7fig4 #h71 #a4e in4 in diameter1 below which is a weight ,b connected with the ball by a short conical stem ,c4 ,the stem ,d is rectangular in section and about #c in4 in length4 ,this is divided into ten equal parts1 each of which is subdivided into five4 ,as in ,boris's instrument1 a series of #i weights1 each of the form shown at ,e1 serves to extend the scale to #ajj principal divisions4 ,in the centre of each weight is a hole capable of admitting the lowest and thickest end of the conical stem ,c1 and a slot is cut into it just wide enough to allow the upper part of the cone to pass4 ,each weight can thus be dropped on to the lower stem so as to rest on the counterpoise ,b4 ,the weights are marked #aj1 #bj1 444 #ij2 and in using the instrument that weight must be selected which will allow it to float in the liquid with a portion only of the stem submerged4 ,then the reading of the scale at the line of flotation1 added to the number on the weight1 gives the reading required4 ,a small supernumerary weight ,f is added1 which can be placed upon the top of the stem4 ,f is so adjusted that when the #fj weight is placed on the lower stem the instrument sinks to the same point in distilled water when ,f is attached as in proof spirit when ,f is removed4 ,the best instruments are now constructed for revenue purposes of silver1 heavily gilded1 because it was found that saccharic acid contained in some spirits attacked brass behind the gilding4 ,the following table gives the specific gravities corresponding to the principal graduations on ,sikes's hydrometer at #fj ,f4 and #fb ,f41 together with the corresponding strengths of spirits4 ,the latter are based upon the tables of ,charles ,gilpin1 clerk to the ,royal ,society1 for which the reader is referred to the ,phil4 ,trans4 for #agid4 ,gilpin's work is a model for its accuracy and thoroughness of detail1 and his results have scarcely been improved upon by more recent workers4 ,the merit of ,sikes's system lies not so much in the hydrometer as in the complete system of tables by which the readings of the instrument are at once converted into percentage of proof-spirit4 ,table showing the ,densities corresponding to the ,indications of ,sike's ,hydrometer4 ---------------------------------------- -------- #fj ,f4 #fb ,f4 ---------------------------------- ,sike's ,proof ,proof ,indications4 ,spirit ,density4 ,spirit ,density4 per cent4 per cent4 ---------------------------------------- ------ #j 4#haebig #afg4j 4#haedjj #aff4e #a 4#hafief #aff4a 4#hagjei #afe4f #b 4#hahfba #afe4c 4#hahgbe #afd4h #c 4#hbjbid #afd4e 4#hbjcig #afc4i #d 4#hbaigc #afc4f 4#hbbjgg #afc4a #e 4#hbcfei #afb4g 4#hbcgfc #afb4c #f 4#hbeceb #afa4h 4#hbedeg #afa4d #g 4#hbgjeb #afj4i 4#hbgaeg #afj4e #h 4#hbhgei #afj4j 4#hbhhfd #aei4f #i 4#hcjdgc #aei4a 4#hcjegh #aeh4g #aj 4#hcbaie #aeh4b 4#hcbcjj #aeg4h #aa 4#hcchhh #aeg4c 4#hcciic #aef4h #ab 4#hceehg #aef4d 4#hcefib #aee4i #ac 4#hcgbid #aee4e 4#hcgdjj #aee4j #ad 4#hcijjh #aed4f 4#hciaad #aed4j #ae 4#hdjgbi #aec4g 4#hdjhce #aec4a #af 4#hdbdeh #aeb4g 4#hdbefd #aeb4a #ag 4#hddaic #aea4g 4#hddbii #aea4a #ah 4#hdeicf #aej4g 4#hdfjdb #aej4a #ai 4#hdgfhe #adi4g 4#hdggib #adi4a #bj 4#hdiddb #adh4g 4#hdiedi #adh4a #bj;,b 4#hdicic #adh4g 4#hdiejj #adh4a #ba 4#heaabb #adg4f 4#heabbi #adg4a #bb 4#hebheg #adf4f 4#hebifd #adf4a #bc 4#hedeii #ade4f 4#hedgjg #ade4a #bd 4#hefcdh #add4f 4#hefdef #add4j #be 4#hehaje #adc4e 4#hehbac #adb4i #bf 4#heihfi #adb4d 4#heiigh #ada4h #bg 4#hfafdj #ada4c 4#hfagdi #adj4h #bh 4#hfcdai #adj4b 4#hfcebh #aci4g #bi 4#hfebjd #aci4a 4#hfecac #ach4e #cj 4#hffiih #ach4j 4#hfgajg #acg4d #cj;,b 4#hffiia #ach4j 4#hfgajj #acg4d #ca 4#hfhgee #acf4i 4#hfhhfe #acf4b #cb 4#hgjebf #ace4g 4#hgjfcf #ace4a #cc 4#hgbcje #acd4e 4#hgbdae #acc4i #cd 4#hgdjij #acc4d 4#hgdbjj #acb4h #ce 4#hgehhc #acb4b 4#hgciid #aca4f #cf 4#hggfhd #aca4j 4#hggiie #acj4d #cg 4#hgidib #abi4h 4#hgifjc #abi4a #ch 4#hhacjg #abh4e 4#hhadai #abg4i #ci 4#hhcabi #abg4c 4#hhcbda #abf4g #dj 4#hhdifj #abf4j 4#hhejgb #abe4d #dj;,b 4#hhdhhh #abf4j 4#hhejjj #abe4d #da 4#hhffhi #abd4h 4#hhfhja #abd4b #db 4#hhhdig #abc4e 4#hhhfji #abb4i #dc 4#hijcab #abb4b 4#hijdbe #aba4f #dd 4#hibace #abj4i 4#hibbdh #abj4c #de 4#hicife #aai4f 4#hidjgh #aai4j #df 4#hiehjc #aah4c 4#hieiaf #aag4f #dg 4#higfdg #aaf4i 4#higgfa #aaf4c #dh 4#hiieji #aae4f 4#hiifad #aad4i #di 4#ijacfj #aad4b 4#ijadag #aac4e #ej 4#ijcbbi #aab4h 4#ijccdc #aab4a #ej;,b 4#ijcahf #aab4h 4#ijccjj #aab4a #ea 4#ijejbd #aaa4d 4#ijeach #aaj4g #eb 4#ijfhfi #aaj4j 4#ijfihc #aji4c #ec 4#ijhgbb #ajh4f 4#ijhhcg #ajg4i #ed 4#iajehb #ajg4a 4#iajfig #ajf4e #ee 4#iabdej #aje4f 4#iabefe #aje4j #ef 4#iadcbf #ajd4b 4#iaddda #ajc4e #eg 4#iafbji #ajb4g 4#iafcbc #ajb4j #eh 4#iahajj #aja4c 4#iahbaf #ajj4e #ei 4#iaiiii #ii4g 4#hbjaae #ih4i #fj 4#ibaijf #ih4a 4#ibbjbb #ig4d #fj;,b 4#ibahhd #ih4a 4#ibbjjj #ig4d #fa 4#ibcgfj #if4f 4#ibchgg #ie4i #fb 4#ibefdc #ie4j 4#ibegfj #id4b #fc 4#ibgecd #ic4c 4#ibgfeb #ib4f #fd 4#ibidcc #ia4g 4#ibieej #ij4i #fe 4#icacci #ij4j 4#icadeg #hi4b #ff 4#iccbed #hh4c 4#icccgb #hg4e #fg 4#iceagf #hf4e 4#icebid #he4h #fh 4#icgajg #hd4g 4#icgbbe #hd4j #fi 4#icijde #hb4i 4#iciafc #hb4b #gj 4#idjiia #ha4a 4#idaaaj #hj4c #gj;,b 4#idjiha #ha4a 4#idaajj #hj4c #ga 4#idbhig #gi4b 4#idcjaf #gh4d #gb 4#iddhai #gg4c 4#iddich #gf4e #gc 4#idfgdi #ge4c 4#idfhfi #gd4e #gd 4#idhfhg #gc4c 4#idhhjg #gb4e #ge 4#iejfcd #ga4b 4#iejgec #gj4d #gf 4#iebehh #fi4j 4#iebgjh #fh4b #gg 4#iedeej #ff4h 4#iedfgj #ff4j #gh 4#iefebj #fd4d 4#ieffda #fc4e #gi 4#iehdih #fa4i 4#iehfai #fa4a #hj 4#ifjdhe #ei4d 4#ifjfjf #eh4e #hj;,b 4#ifjdgi #ei4d 4#ifjfjj #eh4e #ha 4#ifbdcc #ef4g 4#ifbeee #ee4h #hb 4#ifdcie #ec4i 4#ifdeag #ec4j #hc 4#iffcff #ej4i 4#iffdhh #ej4j #hd 4#ifhcdd #dg4h 4#ifhdff #dg4j #he 4#igjcca #dd4e 4#igjdec #dc4h #hf 4#igbcbe #da4j 4#igbddh #dj4d #hg 4#igdcbh #cg4e 4#igddea #cf4i #hh 4#igfcdj #cd4j 4#igfdfc #cc4e #hi 4#ighcei #cj4f 4#ighdhb #cj4a #ij 4#ihjchf #bg4b 4#ihjeaj #bf4g #ij;,b 4#ihjcgf #bg4b 4#ihjejj #bf4g #ia 4#ihbcga #bc4i 4#ihbdif #bc4f #ib 4#ihdcgd #bj4h 4#ihddih #bj4e #ic 4#ihfche #ag4g 4#ihfeaj #ag4d #id 4#ihhdjd #ad4h 4#ihhebi #ad4e #ie 4#iijdca #ab4j 4#iijeeg #aa4g #if 4#iibdfh #i4c 4#iibeic #i4j #ig 4#iideab #f4g 4#iidfcg #f4e #ih 4#iifefe #d4a 4#iiffia #d4j #ii 4#iihfbf #a4h 4#iihgeb #a4f #ajj #a4jjjfif #j4j #a4jjjhbb #j4j ---------------------------------------- ------ ,in the above table for ,sikes's hydrometer two densities are given corresponding to each of the degrees #bj1 #cj1 #dj1 #ej1 #fj1 #gj1 #hj and #ij1 indicating that the successive weights belonging to the particular instrument for which the table has been calculated do not quite agree4 ,the discrepancy1 however1 does not produce any sensible error in the strength of the corresponding spirit4 ,a table which indicates the weight per gallon of spirituous liquors for every degree of ,sikes's hydrometer is printed in #bc and #bd ,vict4 c4 #aad1 schedule ,b4 ,this table differs slightly from that given above1 which has been abridged from the table given in ,keene's ,handbook of ,hydrometry1 apparently on account of the equal divisions on ,sikes's scale having been taken as corresponding to equal increments of density4 ,sikes's hydrometer was established for the purpose of collecting the revenue of the ,united ,kingdom by ,act of ,parliament1 #ef ,geo4 ,,iii4 c4 #adj1 by which it was enacted that all spirits shall be deemed and taken to be of the degree of strength which the said hydrometers called ,sikes's hydrometers shall1 upon trial by any officer or officers of the customs or excise1 denote such spirits to be4 ,this act came into force on ,january #e1 #ahag1 and was to have remained in force until ,august #a1 #ahah1 but was repealed by #eh ,geo4 ,,iii4 c4 #bh1 which established ,sikes's hydrometer on a permanent footing4 ,by #c and #d ,will4 ,,iv4 c4 #eb1 #abc1 it was further enacted that the same instruments and methods should be employed in determining the duty upon imported spirits as should in virtue of any ,act of ,parliament be employed in the determination of the duty upon spirits distilled at home4 ,it is the practice of the officers of the inland revenue to adjust ,sikes's hydrometer at #fb ,f41 that being the temperature at which the imperial gallon is defined as containing #aj lb4 avoirdupois of distilled water4 ,the specific gravity of any sample of spirits thus determined1 when multiplied by ten1 gives the weight in pounds per imperial gallon1 and the weight of any bulk of spirits divided by this number gives its volume at once in imperial gallons4 ,mr 7afterwards ,colonel7 ,j4 ,b4 ,keene1 of the ,hydrometer ,office1 ,london1 has constructed an instrument after the model of ,sikes's1 but provided with twelve weights of different masses but equal volumes1 and the instrument is never used without having one of these attached4 ,when loaded with either of the lightest two weights the instrument is specifically lighter than ,sikes's hydrometer when unloaded1 and it may thus be used for specific gravities as low as that of absolute alcohol4 ,the volume of each weight being the same1 the whole volume immersed is always the same when it floats at the same mark whatever weight may be attached4 ,besides the above1 many hydrometers have been employed for special purposes4 ,twaddell's hydrometer is adapted for densities greater than that of water4 ,the scale is so arranged that the reading multiplied by #e and added to #ajjj gives the specific gravity with reference to water as #ajjj4 ,to avoid an inconveniently long stem1 different instruments are employed for different parts of the scale as mentioned above4 ,the lactometer constructed by ,dicas of ,liverpool is adapted for the determination of the quality of milk4 ,it resembles ,sikes's hydrometer in other respects1 but is provided with eight weights4 ,it is also provided with a thermometer and slide rule1 to reduce the readings to the standard temperature of #ee ,f4 ,any determination of density can be taken only as affording prima facie evidence of the quality of milk1 as the removal of cream and the addition of water are operations which tend to compensate each other in their influence on the density of the liquid1 so that the lactometer cannot be regarded as a reliable instrument4 ,the marine hydrometers1 as supplied by the ,british government to the royal navy and the merchant marine1 are glass instruments with slender stems1 and generally serve to indicate specific gravities from #a4jjj to #a4jdj4 ,before being issued they are compared with a standard instrument1 and their errors determined4 ,they are employed for taking observations of the density of sea-water4 ,the salinometer is a hydrometer originally intended to indicate the strength of the brine in marine boilers in which sea-water is employed4 ,saunders's salinometer consists of a hydrometer which floats in a chamber through which the water from the boiler is allowed to flow in a gentle stream1 at a temperature of #bjj ,f4 ,the peculiarity of the instrument consists in the stream of water1 as it enters the hydrometer chamber1 being made to impinge against a disk of metal1 by which it is broken into drops1 thus liberating the steam1 which would otherwise disturb the instrument4 ,the use of ,sikes's hydrometer necessitates the employment of a considerable quantity of spirit4 ,for the testing of spirits in bulk no more convenient instrument has been devised1 but where very small quantities are available more suitable laboratory methods must be adopted4 ,in ,england1 the ,finance ,act #aijg 7#g ,ed4 ,,vii4 c4 #ac71 section #d1 provides as follows3 7#a7 ,the ,commissioners of ,customs and the ,commissioners of ,inland ,revenue may jointly make regulations authorizing the use of any means described in the regulations for ascertaining for any purpose the strength or weight of spirits4 7#b7 ,where under any enactment ,sykes's 7sic7 ,hydrometer is directed to be used or may be used for the purpose of ascertaining the strength or weight of spirits1 any means so authorized by regulations may be used instead of ,sykes's ,hydrometer and references to ,sykes's ,hydrometer in any enactment shall be construed accordingly4 7#c7 ,any regulations made under this section shall be published in the ,london1 ,edinburgh and ,dublin ,gazette1 and shall take effect from the date of publication1 or such later date as may be mentioned in the regulations for the purpose4 7#d7 ,the expression spirits in this section has the same meaning as in the ,spirits ,act #ahhj4 7,w4 ,g47 ,,footnotes3 #a ,in ,nicholson's ,journal1 iii4 #hi1 ,citizen ,eusebe ,salverte calls attention to the poem ,de ,ponderibus et ,mensuris generally ascribed to ,rhemnius ,fannius ,palaemon1 and consequently #cjj years older than ,hypatia1 in which the hydrometer is described and attributed to ,archimedes4 #b ,nicholson's ,journal1 vol4 i4 p4 #aaa1 footnote4 ,,hydropathy1 the name given1 from the ,greek1 to the water-cure1 or the treatment of disease by water1 used outwardly and inwardly4 ,like many descriptive names1 the word hydropathy is defective and even misleading1 the active agents in the treatment being heat and cold1 of which water is little more than the vehicle1 and not the only one4 ,thermotherapeutics 7or thermotherapy7 is a term less open to objection4 ,hydropathy1 as a formal system1 dates from about #ahbi1 when ,vincenz ,priessnitz 7#ahja-ahea71 a farmer of ,grfenberg in ,silesia1 ,austria1 began his public career in the paternal homestead1 extended so as to accommodate the increasing numbers attracted by the fame of his cures4 ,two ,english works1 however1 on the medical uses of water had been translated into ,german in the century preceding the rise of the movement under ,priessnitz4 ,one of these was by ,sir ,john ,floyer 7#afdi-agcd71 a physician of ,lichfield1 who1 struck by the remedial use of certain springs by the neighbouring peasantry1 investigated the history of cold bathing1 and published in #agjb his ,greek3 ,psychrolousia1 or the ,history of ,cold ,bathing1 both ,ancient and ,modern4 ,the book ran through six editions within a few years1 and the translation was largely drawn upon by ,dr ,j4 ,s4 ,hahn of ,silesia1 in a work published in #agch1 ,on the ,healing ,virtues of ,cold ,water1 ,inwardly and ,outwardly applied1 as proved by ,experience4 ,the other work was that of ,dr ,james ,currie 7#agef-ahje7 of ,liverpool1 entitled ,medical ,reports on the ,effects of ,water1 ,cold and ,warm1 as a remedy in ,fevers and other ,diseases1 published in #agig1 and soon after translated into ,german by ,michaelis 7#ahja7 and ,hegewisch 7#ahjg74 ,it was highly popular1 and first placed the subject on a scientific basis4 ,hahn's writings had meanwhile created much enthusiasm among his countrymen1 societies having been everywhere formed to promote the medicinal and dietetic use of water2 and in #ahjd ,professor rtel of ,ansbach republished them and quickened the popular movement by unqualified commendation of water drinking as a remedy for all diseases4 ,in him the rising ,priessnitz found a zealous advocate1 and doubtless an instructor also4 ,at ,grfenberg1 to which the fame of ,priessnitz drew people of every rank and many countries1 medical men were conspicuous by their numbers1 some being attracted by curiosity1 others by the desire of knowledge1 but the majority by the hope of cure for ailments which had as yet proved incurable4 ,many records of experiences at ,grfenberg were published1 all more or less favourable to the claims of ,priessnitz1 and some enthusiastic in their estimate of his genius and penetration2 ,captain ,claridge introduced hydropathy into ,england in #ahdj1 his writings and lectures1 and later those of ,sir ,w4 ,erasmus ,wilson 7#ahji-ahhd71 ,james ,manby ,gully 7#ahjh-ahhc7 and ,edward ,johnson1 making numerous converts1 and filling the establishments opened soon after at ,malvern and elsewhere4 ,in ,germany1 ,france and ,america hydropathic establishments multiplied with great rapidity4 ,antagonism ran high between the old practice and the new4 ,unsparing condemnation was heaped by each on the other2 and a legal prosecution1 leading to a royal commission of inquiry1 served but to make ,priessnitz and his system stand higher in public estimation4 ,increasing popularity diminished before long that timidity which had in great measure prevented trial of the new method from being made on the weaker and more serious class of cases1 and had caused hydropathists to occupy themselves mainly with a sturdy order of chronic invalids well able to bear a rigorous regimen and the severities of unrestricted crisis4 ,the need of a radical adaptation to the former class was first adequately recognized by ,john ,smedley1 a manufacturer of ,derbyshire1 who1 impressed in his own person with the severities as well as the benefits of the cold water cure1 practised among his workpeople a milder form of hydropathy1 and began about #aheb a new era in its history1 founding at ,matlock a counterpart of the establishment at ,grfenberg4 ,ernst ,brand 7#ahbf-ahig7 of ,berlin1 ,rljen and ,theodor von ,jrgensen of ,kiel1 and ,karl ,liebermeister 7#ahcc-aija7 of ,basel1 between #ahfj and #ahgj1 employed the cooling bath in abdominal typhus with striking results1 and led to its introduction to ,england by ,dr ,wilson ,fox4 ,in the ,franco-,german war the cooling bath was largely employed1 in conjunction frequently with quinine2 and it now holds a recognized position in the treatment of hyperpyrexia4 ,the wet sheet pack has become part of medical practice2 the ,turkish bath1 introduced by ,david ,urquhart 7#ahje-ahgg7 into ,england on his return from the ,east1 and ardently adopted by ,dr ,richard ,barter 7#ahjb-ahgj7 of ,cork1 has become a public institution1 and1 with the morning tub and the general practice of water drinking1 is the most noteworthy of the many contributions by hydropathy to public health 7see ,,baths1 ad fin474 ,the appliances and arrangements by means of which heat and cold are brought to bear on the economy are--7a7 ,packings1 hot and cold1 general and local1 sweating and cooling2 7b7 hot air and steam baths2 7c7 general baths1 of hot water and cold2 7d7 sitz1 spinal1 head and foot baths2 7e7 bandages 7or compresses71 wet and dry2 also 7f7 fomentations and poultices1 hot and cold1 sinapisms1 stupes1 rubbings and water potations1 hot and cold4 7a7 ,packings4--,the full pack consists of a wet sheet enveloping the body1 with a number of dry blankets packed tightly over it1 including a macintosh covering or not4 ,in an hour or less these are removed and a general bath administered4 ,the pack is a derivative1 sedative1 sudorific and stimulator of cutaneous excretion4 ,there are numerous modifications of it1 notably the cooling pack1 where the wrappings are loose and scanty1 permitting evaporation1 and the application of indefinite duration1 the sheet being rewetted as it dries2 this is of great value in protracted febrile conditions4 ,there are also local packs1 to trunk1 limbs or head separately1 which are derivative1 soothing or stimulating1 according to circumstance and detail4 7b7 ,hot air baths1 the chief of which is the ,turkish 7properly1 the ,roman7 bath1 consisting of two or more chambers ranging in temperature from #abj to #bab or higher1 but mainly used at #aej for curative purposes4 ,exposure is from twenty minutes up to two hours according to the effect sought1 and is followed by a general bath1 and occasionally by soaping and shampooing4 ,it is stimulating1 derivative1 depurative1 sudorific and alterative1 powerfully promoting tissue change by increase of the natural waste and repair4 ,it determines the blood to the surface1 reducing internal congestions1 is a potent diaphoretic1 and1 through the extremes of heat and cold1 is an effective nervous and vascular stimulant and tonic4 ,morbid growths and secretions1 as also the uraemic1 gouty and rheumatic diathesis1 are beneficially influenced by it4 ,the full pack and ,turkish bath have between them usurped the place and bettered the function of the once familiar hot bath4 ,the ,russian or steam bath and the lamp bath are primitive and inferior varieties of the modern ,turkish bath1 the atmosphere of which cannot be too dry and pure4 7c7 ,general baths comprise the rain 7or needle71 spray 7or rose71 shower1 shallow1 plunge1 douche1 wave and common morning sponge baths1 with the dripping sheet1 and hot and cold spongings1 and are combinations1 as a rule1 of hot and cold water4 ,they are stimulating1 tonic1 derivative and detergent4 7d7 ,local baths comprise the sitz 7or sitting71 douche 7or spouting71 spinal1 foot and head baths1 of hot or cold water1 singly or in combination1 successive or alternate4 ,the sitz1 head and foot baths are used flowing on occasion4 ,the application of cold by ,leiter's tubes is effective for reducing inflammation 7e4g4 in meningitis and in sunstroke72 in these a network of metal or indiarubber tubing is fitted to the part affected1 and cold water kept continuously flowing through them4 ,rapid alternations of hot and cold water have a powerful effect in vascular stasis and lethargy of the nervous system and absorbents1 yielding valuable results in local congestions and chronic inflammations4 7e7 ,bandages 7or compresses7 are of two kinds1--cooling1 of wet material left exposed for evaporation1 used in local inflammations and fevers2 and heating1 of the same1 covered with waterproof material1 used in congestion1 external or internal1 for short or long periods4 ,poultices1 warm1 of bread1 linseed1 bran1 c41 changed but twice in twenty-four hours1 are identical in action with the heating bandage1 and superior only in the greater warmth and consequent vital activity their closer application to the skin ensures4 7f7 ,fomentations and poultices1 hot or cold1 sinapisms1 stupes1 rubefacients1 irritants1 frictions1 kneadings1 calisthenics1 gymnastics1 electricity1 c41 are adjuncts largely employed4 ,,bibliography4--,among the numerous earlier works on hydropathy1 the following are worth mention3 ,balbirnie1 ,water ,cure in ,consumption 7#ahdg71 ,hydropathic ,aphorisms 7#ahef7 and ,a ,plea for the ,turkish ,bath 7#ahfb72 ,beni-,barde1 ,trait d'hydrothrapie 7#ahgd72 ,claridge1 ,cold ,water ,cure1 or ,hydropathy 7#ahda71 ,facts and ,evidence in ,support of ,hydropathy 7#ahdc7 and ,cold ,water1 ,tepid ,water and ,friction ,cure 7#ahdi72 ,dunlop1 ,philosophy of the ,bath 7#ahgc72 ,floyer1 ,psychrolousia1 or the ,history of ,cold-,bathing1 c4 7#agjb72 ,j4 ,s4 ,hahn 7,schweidnitz71 ,observations on the ,healing ,virtues of ,cold ,water 7#agch72 ,hunter1 ,hydropathy for ,home ,use 7#ahgi72 ,e4 ,w4 ,lane1 ,hydropathy1 or the ,natural ,system of ,medical ,treatment 7#aheg72 ,r4 ,j4 ,lane1 ,life at the ,water ,cure 7#ahea72 ,shew1 ,hydropathic ,family ,physician 7#aheg72 ,smedley1 ,practical ,hydropathy 7#ahgi72 ,smethurst1 ,hydrotherapia1 or the ,water ,cure 7#ahdc72 ,wainwright1 ,inquiry into the ,nature and ,use of ,baths 7#agcg72 ,weiss1 ,handbook of ,hydropathy 7#ahdd72 ,wilson ,principles and ,practice of the ,cold ,water ,cure 7#ahed7 and ,the ,water ,cure 7#ahei74 ,a useful recent work dealing comprehensively with the subject is ,richard ,metcalfe's ,rise and ,progress of ,hydropathy 7#aijf74 ,,hydrophobia 7,gr4 ,greek3 ,hydor1 water1 and ,greek3 phobos1 fear2 so called from the symptom of dread of water71 or ,,rabies 7,lat4 for madness71 an acute disease1 occurring chiefly in certain of the lower animals1 particularly the canine species1 and liable to be communicated by them to other animals and to man4 ,in ,dogs1 c4--,the occurrence of rabies in the fox1 wolf1 hyaena1 jackal1 raccoon1 badger and skunk has been asserted2 but there is every probability that it is originally a disease of the dog4 ,it is communicated by inoculation to nearly all1 if not all1 warm-blooded creatures4 ,the transmission from one animal to another only certainly takes place through inoculation with viruliferous matters4 ,the malady is generally characterized at a certain stage by an irrepressible desire in the animal to act offensively with its natural weapons--dogs and other carnivora attacking with their teeth1 herbivora with their hoofs or horns1 and birds with their beaks1 when excited ever so slightly4 ,in the absence of excitement the malady may run its course without any fit of fury or madness4 ,symptoms4--,the disease has been divided into three stages or periods1 and has also been described as appearing in at least two forms1 according to the peculiarities of the symptoms4 ,but1 as a rule1 one period of the disease does not pass suddenly into another1 the transition being almost imperceptible2 and the forms do not differ essentially from each other1 but appear merely to constitute varieties of the same disease1 due to the natural disposition of the animal1 or other modifying circumstances4 ,these forms have been designated true or furious rabies 7,fr4 rage vrai2 ,ger4 rasende ,wuth7 and dumb rabies 7,fr4 rage mue2 ,ger4 stille ,wuth74 ,the malady does not commence with fury and madness1 but in a strange and anomalous change in the habits of the dog3 it becomes dull1 gloomy1 and taciturn1 and seeks to isolate itself in out-of-the-way places1 retiring beneath chairs and to odd corners4 ,but in its retirement it cannot rest3 it is uneasy and fidgety1 and no sooner has it lain down than suddenly it jumps up in an agitated manner1 walks backwards and forwards several times1 again lies down and assumes a sleeping attitude1 but has only maintained it for a few minutes when it is once more moving about4 ,again it retires to its corner1 to the farthest recess it can find1 and huddles itself up into a heap1 with its head concealed beneath its chest and fore-paws4 ,this state of continual agitation and inquietude is in striking contrast with its ordinary habits1 and should therefore receive attention4 ,not unfrequently there are a few moments when the creature appears more lively than usual1 and displays an extraordinary amount of affection4 ,sometimes there is a disposition to gather up straw1 thread1 bits of wood1 c41 which are industriously carried away2 a tendency to lick anything cold1 as iron1 stones1 c41 is also observed in many instances2 and there is also a desire evinced to lick other animals4 ,sexual excitement is also frequently an early symptom4 ,at this period no disposition to bite is observed2 the animal is docile with its master and obeys his voice1 though not so readily as before1 nor with the same pleased countenance4 ,there is something strange in the expression of its face1 and the voice of its owner is scarcely able to make it change from a sudden gloominess to its usual animated aspect4 ,these symptoms gradually become more marked2 the restlessness and agitation increase4 ,if on straw the dog scatters and pulls it about with its paws1 and if in a room it scratches and tumbles the cushions or rugs on which it usually lies4 ,it is incessantly on the move1 rambling about1 scratching the ground1 sniffing in corners and at the doors1 as if on the scent or seeking for something4 ,it indulges in strange movements1 as if affected by some mental influences or a prey to hallucinations4 ,when not excited by any external influence it will remain for a brief period perfectly still and attentive1 as if watching something1 or following the movements of some creature on the wall2 then it will suddenly dart forward and snap at the vacant air1 as if pursuing an annoying object1 or endeavouring to seize a fly4 ,at another time it throws itself1 yelling and furious1 against the wall1 as if it heard threatening voices on the other side1 or was bent on attacking an enemy4 ,nevertheless1 the animal is still docile and submissive1 for its master's voice will bring it out of its frenzy4 ,but the saliva is already virulent1 and the excessive affection which it evinces at intervals1 by licking the hands or face of those it loves1 renders the danger very great should there be a wound or abrasion4 ,until a late period in the disease the master's voice has a powerful influence over the animal4 ,when it has escaped from all control and wanders erratically abroad1 ferocious and restless1 and haunted by horrid phantoms1 the familiar voice yet exerts its influence1 and it is rare indeed that it attacks its master4 ,there is no dread of water in the rabid dog2 the animal is generally thirsty1 and if water be offered will lap it with avidity1 and swallow it at the commencement of the disease4 ,and when1 at a later period1 the constriction about the throat--symptomatic of the disease--renders swallowing difficult1 the dog will none the less endeavour to drink1 and the lappings are as frequent and prolonged when deglutition becomes impossible4 ,so little dread has the rabid dog of water that it will ford streams and swim rivers2 and when in the ferocious stage it will even do this in order to attack other creatures on the opposite side4 ,at the commencement of the disease the dog does not usually refuse to eat1 and some animals are voracious to an unusual degree4 ,but in a short time it becomes fastidious1 only eating what it usually has a special predilection for4 ,soon1 however1 this gives place to a most characteristic symptom--either the taste becomes extremely depraved or the dog has a fatal and imperious desire to bite and ingest everything4 ,the litter of its kennel1 wool from cushions1 carpets1 stockings1 slippers1 wood1 grass1 earth1 stones1 glass1 horse-dung1 even its own faeces and urine1 or whatever else may come in its way1 are devoured4 ,on examination of the body of a dog which has died of rabies it is so common to find in the stomach a quantity of dissimilar and strange matters on which the teeth have been exercised that1 if there was nothing known of the animal's history1 there would be strong evidence of its having been affected with the disease4 ,when a dog1 then1 is observed to gnaw and eat suchlike matters1 though it exhibits no tendency to bite1 it should be suspected4 ,the mad dog does not usually foam at the mouth to any great extent at first4 ,the mucus of the mouth is not much increased in quantity1 but it soon becomes thicker1 viscid1 and glutinous1 and adheres to the angles of the mouth1 fauces and teeth4 ,it is at this period that the thirst is most ardent1 and the dog sometimes furiously attempts to detach the saliva with its paws2 and if after a while it loses its balance in these attempts and tumbles over1 there can no longer be any doubt as to the nature of the malady4 ,there is another symptom connected with the mouth in that form of the disease named dumb madness which has frequently proved deceptive4 ,the lower jaw drops in consequence of paralysis of its muscles1 and the mouth remains open4 ,the interior is dry from the air passing continually over it1 and assumes a deep red tint1 somewhat masked by patches of dust or earth1 which more especially adhere to the upper surface of the tongue and to the lips4 ,the strange alteration produced in the dog's physiognomy by its constantly open mouth and the dark colour of the interior is rendered still more characteristic by the dull1 sad1 or dead expression of the animal's eyes4 ,in this condition the creature is not very dangerous1 because generally it could not bite if it tried--indeed there does not appear to be much desire to bite in dumb madness2 but the saliva is none the less virulent1 and accidental inoculations with it1 through imprudent handling1 will prove as fatal as in the furious form4 ,the mouth should not be touched1--numerous deaths having occurred through people thinking the dog had some foreign substance lodged in its throat1 and thrusting their fingers down to remove it4 ,the sensation of tightness which seems to exist at the throat causes the dog to act as if a bone were fixed between its teeth or towards the back of its mouth1 and to employ its fore-paws as if to dislodge it4 ,this is a very deceptive symptom1 and may prove equally dangerous if caution be not observed4 ,vomiting of blood or a chocolate-coloured fluid is witnessed in some cases1 and has been supposed to be due to the foreign substances in the stomach1 which abrade the lining membrane2 this1 however1 is not correct1 as it has been observed in man4 ,the voice of the rabid dog is very peculiar1 and so characteristic that to those acquainted with it nothing more is needed to prove the presence of the disease4 ,those who have heard it once or twice never forget its signification4 ,owing to the alterations taking place in the larynx the voice becomes hoarse1 cracked and stridulous1 like that of a child affected with croup--the voix du coq1 as the ,french have it4 ,a preliminary bark is made in a somewhat elevated tone and with open mouth2 this is immediately succeeded by five1 six or eight decreasing howls1 emitted when the animal is sitting or standing1 and always with the nose elevated1 which seem to come from the depths of the throat1 the jaws not coming together and closing the mouth during such emission1 as in the healthy bark4 ,this alteration in the voice is frequently the first observable indication of the malady1 and should at once attract attention4 ,in dumb madness the voice is frequently lost from the very commencement--hence the designation4 ,the sensibility of the mad dog appears to be considerably diminished1 and the animal appears to have lost the faculty of expressing the sensations it experiences3 it is mute under the infliction of pain1 though there can be no doubt that it still has peripheral sensation to some extent4 ,burning1 beating and wounding produce much less effect than in health1 and the animal will even mutilate itself with its teeth4 ,suspicion1 therefore1 should always strongly attach to a dog which does not manifest a certain susceptibility to painful impressions and receives punishment without any cry or complaint4 ,there is also reason for apprehension when a dog bites itself persistently in any part of its body4 ,a rabid dog is usually stirred to fury at the sight of one of its own species2 this test has been resorted to by ,henrie ,marie ,bouley 7#ahad-ahhe7 to dissipate doubts as to the existence of the disease when the diagnosis is otherwise uncertain4 ,as soon as the suspected animal1 if it is really rabid1 finds itself in the presence of another of its species it at once assumes the aggressive1 and1 if allowed1 will bite furiously4 ,all rabid animals indeed become excited1 exasperated1 and furious at the sight of a dog1 and attack it with their natural weapons1 even the timid sheep when rabid butts furiously at the enemy before which in health it would have fled in terror4 ,this inversion of sentiment is sometimes valuable in diagnosing the malady2 it is so common that it may be said to be present in every case of rabies4 ,when1 therefore1 a dog1 contrary to its habits and natural inclination1 becomes suddenly aggressive to other dogs1 it is time to take precautions4 ,in the large majority of instances the dog is inoffensive in the early period of the disease to those to whom it is familiar4 ,it then flies from its home and either dies1 is killed as mad1 or returns in a miserable plight1 and in an advanced stage of the malady1 when the desire to bite is irresistible4 ,it is in the early stage that sequestration and suppressive measures are most valuable4 ,the dogs which propagate the disease are usually those that have escaped from their owners4 ,after two or three days1 frequently in about twelve hours1 more serious and alarming symptoms appear1 ferocious instincts are developed1 and the desire to do injury is irrepressible4 ,the animal has an indefinable expression of sombre melancholy and cruelty4 ,the eyes have their pupils dilated1 and emit flashes of light when they are not dull and heavy2 they always appear so fierce as to produce terror in the beholder2 they are red1 and their sensibility to light is increased2 and wrinkles1 which sometimes appear on the forehead1 add to the repulsive aspect of the animal4 ,if caged it flies at the spectator1 emitting its characteristic howl or bark1 and seizing the iron bars with its teeth1 and if a stick be thrust before it this is grasped and gnawed4 ,this fury is soon succeeded by lassitude1 when the animal remains insensible to every excitement4 ,then all at once it rouses up again1 and another paroxysm of fury commences4 ,the first paroxysm is usually the most intense1 and the fits vary in duration from some hours to a day1 and even longer2 they are ordinarily briefer in trained and pet dogs than in those which are less domesticated1 but in all the remission is so complete after the first paroxysm that the animals appear to be almost well1 if not in perfect health4 ,during the paroxysms respiration is hurried and laboured1 but tranquil during the remissions4 ,there is an increase of temperature1 and the pulse is quick and hard4 ,when the animal is kept in a dark place and not excited1 the fits of fury are not observed4 ,sometimes it is agitated and restless in the manner already described4 ,it never becomes really furious or aggressive unless excited by external objects--the most potent of these1 as has been said1 being another dog1 which1 however1 if it be admitted to its cage1 it may not at once attack4 ,the attacked animal rarely retaliates1 but usually responds to the bites by acute yells1 which contrast strangely with the silent anger of the aggressor1 and tries to hide its head with its paws or beneath the straw4 ,these repeated paroxysms hurry the course of the disease4 ,the secretion and flowing of a large quantity of saliva from the mouth are usually only witnessed in cases in which swallowing has become impossible1 the mouth being generally dry4 ,at times the tongue1 nose and whole head appear swollen4 ,other dogs frequently shun one which is rabid1 as if aware of their danger4 ,the rabid dog1 if lodged in a room or kept in a house1 is continually endeavouring to escape2 and when it makes its escape it goes freely forward1 as if impelled by some irresistible force4 ,it travels considerable distances in a short time1 perhaps attacking every living creature it meets--preferring dogs1 however1 to other animals1 and these to mankind2 cats1 sheep1 cattle and horses are particularly liable to be injured4 ,it attacks in silence1 and never utters a snarl or a cry of anger2 should it chance to be hurt in return it emits no cry or howl of pain4 ,the degree of ferocity appears to be related to natural disposition and training4 ,some dogs1 for instance1 will only snap or give a slight bite in passing1 while others will bite furiously1 tearing the objects presented to them1 or which they meet in their way1 and sometimes with such violence as to injure their mouth and break their teeth1 or even their jaws4 ,if chained1 they will in some cases gnaw the chain until their teeth are worn away and the bones laid bare4 ,the rabid dog does not continue its progress very long4 ,exhausted by fatigue and the paroxysms of madness excited in it by the objects it meets1 as well as by hunger1 thirst1 and also1 no doubt1 by the malady1 its limbs soon become feeble2 the rate of travelling is lessened and the walk is unsteady1 while its drooping tall1 head inclined towards the ground1 open mouth1 and protruded tongue 7of a leaden colour or covered with dust7 give the distressed creature a very striking and characteristic physiognomy4 ,in this condition1 however1 it is much less to be dreaded than in its early fits of fury1 since it is no longer capable or desirous of altering its course or going out of its way to attack an animal or a man not immediately in the path4 ,it is very probable that its fast-failing vision1 deadened scent1 and generally diminished perception prevent its being so readily impressed or excited by surrounding objects as it previously was4 ,to each paroxysm1 which is always of short duration1 there succeeds a degree of exhaustion as great as the fits have been violent and oft repeated4 ,this compels the animal to stop2 then it shelters itself in obscure places--frequently in ditches by the roadside--and lies there in a somnolescent state for perhaps hours4 ,there is great danger1 nevertheless1 in disturbing the dog at this period2 for when roused from its torpor it has sometimes sufficient strength to inflict a bite4 ,this period1 which may be termed the second stage1 is as variable in its duration as the first1 but it rarely exceeds three or four days4 ,the above-described phenomena gradually merge into those of the third or last period1 when symptoms of paralysis appear1 which are speedily followed by death4 ,during the remission in the paroxysms these paralytic symptoms are more particularly manifested in the hind limbs1 which appear as if unable to support the animal's weight1 and cause it to stagger about2 or the lower jaw becomes more or less drooping1 leaving the parched mouth partially open4 ,emaciation rapidly sets in1 and the paroxysms diminish in intensity1 while the remissions become less marked4 ,the physiognomy assumes a still more sinister and repulsive aspect2 the hair is dull and erect2 the flanks are retracted2 the eyes lose their lustre and are buried in the orbits1 the pupil being dilated1 and the cornea dull and semi-opaque2 very often1 even at an early period1 the eyes squint1 and this adds still more to the terrifying appearance of the poor dog4 ,the voice1 if at all heard1 is husky1 the breathing laborious1 and the pulse hurried and irregular4 ,gradually the paralysis increases1 and the posterior extremities are dragged as if the animal's back were broken1 until at length it becomes general2 it is then the prelude to death4 ,or the dog remains lying in a state of stupor1 and can only raise itself with difficulty on the fore-limbs when greatly excited4 ,in this condition it may yet endeavour to bite at objects within its reach4 ,at times convulsions of a tetanic character appear in certain muscles2 at other times these are general4 ,a comatose condition ensues1 and the rabid dog1 if permitted to die naturally1 perishes1 in the great majority of cases1 from paralysis and asphyxia4 ,in dumb madness there is paralysis of the lower jaw1 which imparts a curious and very characteristic physiognomy to the dog2 the voice is also lost1 and the animal can neither eat nor drink4 ,in this condition the creature remains with its jaw pendent and the mouth consequently wide open1 showing the flaccid or swollen tongue covered with brownish matter1 and a stringy gelatinous-looking saliva lying between it and the lower lip and coating the fauces1 which sometimes appear to be inflamed4 ,though the animal is unable to swallow fluids1 the desire to drink is nevertheless intense2 for the creature will thrust its face into the vessel of water in futile attempts to obtain relief1 even until the approach of death4 ,water may be poured down its throat without inducing a paroxysm4 ,the general physiognomy and demeanour of the poor creature inspire the beholder with pity rather than fear4 ,the symptoms due to cerebral excitement are less marked than in the furious form of the disease2 the agitation is not so considerable1 and the restlessness1 tendency to run away1 and desire to bite are nearly absent2 generally the animal is quite passive4 ,not unfrequently one or both eyes squint1 and it is only when very much excited that the dog may contrive to close its mouth4 ,sometimes there is swelling about the pharynx and the neck2 when the tongue shares in this complication it hangs out of the mouth4 ,in certain cases there is a catarrhal condition of the membrane lining the nasal cavities1 larynx1 and bronchi2 sometimes the animal testifies to the existence of abdominal pain1 and the faeces are then soft or fluid4 ,the other symptoms--such as the rapid exhaustion and emaciation1 paralysis of the posterior limbs towards the termination of the disease1 as well as the rapidity with which it runs its course--are the same as in the furious form4 ,the simultaneous occurrence of furious and dumb madness has frequently been observed in packs of fox-hounds4 ,dumb madness differs1 then1 from the furious type in the paralysis of the lower jaw1 which hinders the dog from biting1 save in very exceptional circumstances2 the ferocious instincts are also in abeyance2 and there is no tendency to aggression4 ,it has been calculated that from #ae to #bj of rabid dogs have this particular form of the disease4 ,puppies and young dogs chiefly have furious rabies4 ,these are the symptoms of rabies in the dog2 but it is not likely1 nor is it necessary1 that they will all be present in every case4 ,in other species the symptoms differ more or less from those manifested by the dog1 but they are generally marked by a change in the manner and habits of the creatures affected1 with strong indications of nervous disturbance1 in the majority of species amounting to ferociousness and a desire to injure1 timid creatures becoming bold and aggressive4 ,in ,human ,beings4--,the disease of hydrophobia has been known from early times1 and is alluded to in the works of ,aristotle1 ,xenophon1 ,plutarch1 ,virgil1 ,horace1 ,ovid and many others1 as well as in those of the early writers on medicine4 ,celsus gives detailed instructions respecting the treatment of men who have been bitten by rabid dogs1 and dwells on the dangers attending such wounds4 ,after recommending suction of the bitten part by means of a dry cupping glass1 and thereafter the application of the actual cautery or of strong caustics1 and the employment of baths and various internal remedies1 he says3 ,idque cum ita per triduum factum est1 tutus esse homo a periculo videtur4 ,solet autem ex eo vulnere1 ubi parum occursum est1 aquae timor nasci1 ,greek3 hydrophobian ,graeci appellant4 ,miserrimum genus morbi2 in quo simul aeger et siti et aquae metu cruciatur2 quo oppressis in angusto spes est4 ,subsequently ,galen described minutely the phenomena of hydrophobia1 and recommended the excision of the wounded part as a protection against the disease4 ,throughout many succeeding centuries little or nothing was added to the facts which the early physicians had made known upon the subject4 ,the malady was regarded with universal horror and dread1 and the unfortunate sufferers were generally abandoned by all around them and left to their terrible fate4 ,in later times the investigations of ,boerhaave1 ,gerard van ,swieten 7#agjj-aggb71 ,john ,hunter1 ,franois ,magendie 7#aghc-ahee71 ,gilbert ,breschet 7#aghd-ahde71 ,virchow1 ,albert ,reder1 as also of ,william ,youatt 7#aggf-ahdg71 ,george ,fleming1 ,meynell1 ,karl ,hertwig 7#agih-ahha71 and others1 have furnished important information2 but all these were put into the shade by the researches of ,pasteur4 ,the disease is communicated by the secretions of the mouth of the affected animal entering a wound or abrasion of the human skin or mucous membrane4 ,in the great majority of cases 7#ij7 this is due to the bite of a rabid dog1 but bites of rabid cats1 wolves1 foxes1 jackals1 c4 are occasionally the means of conveying the disease4 ,numerous popular fallacies still prevail on the subject of hydrophobia4 ,thus it is supposed that the bite of an angry dog may produce the disease1 and all the more if the animal should subsequently develop symptoms of rabies4 ,the ground for this erroneous notion is the fact1 which is unquestionable1 that animals in whom rabies is in the stage of incubation1 during which there are few if any symptoms1 may by their bites convey the disease1 though fortunately during this early stage they are little disposed to bite4 ,the bite of a non-rabid animal1 however enraged1 cannot give rise to hydrophobia4 ,the period of incubation of the disease1 or that time which elapses between the introduction of the virus and the development of the symptoms1 appears to vary in a remarkable degree1 being in some cases as short as a fortnight1 and in others as long as several months or even years4 ,on an average it seems to be from about six weeks to three months1 but it mainly depends on the part bitten2 bites on the head are the most dangerous4 ,the incubation period is also said to be shorter in children4 ,the rare instances of the appearance of hydrophobia many years after the introduction of the poison are always more or less open to question as to subsequent inoculation4 ,when the disease is about to declare itself it not unfrequently happens that the wound1 which had quickly and entirely healed after the bite1 begins to exhibit evidence of irritation or inflammatory action1 or at least to be the seat of morbid sensations such as numbness1 tingling or itching4 ,the symptoms characterizing the premonitory stage are great mental depression and disquietude1 together with restlessness and a kind of indefinite fear4 ,there is an unusual tendency to talk1 and the articulation is abrupt and rapid4 ,although in some instances the patients will not acknowledge that they have been previously bitten1 and deny it with great obstinacy1 yet generally they are well aware of the nature of their malady1 and speak despairingly of its consequences4 ,there is in this early stage a certain amount of constitutional disturbance showing itself by feverishness1 loss of appetite1 sleeplessness1 headache1 great nervous excitability1 respiration of a peculiar sighing or sobbing character1 and even occasionally a noticeable aversion to liquids4 ,these symptoms--constituting what is termed the melancholic stage--continue in general for one or two days1 when they are succeeded by the stage of excitement in which all the characteristic phenomena of the malady are fully developed4 ,sometimes the disease first shows itself in this stage1 without antecedent symptoms4 ,the agitation of the sufferer now becomes greatly increased1 and the countenance exhibits anxiety and terror4 ,there is noticed a marked embarrassment of the breathing1 but the most striking and terrible features of this stage are the effects produced by attempts to swallow fluids4 ,the patient suffers from thirst and desires eagerly to drink1 but on making the effort is seized with a most violent suffocative paroxysm produced by spasm of the muscles of swallowing and breathing1 which continues for several seconds1 and is succeeded by a feeling of intense alarm and distress4 ,with great caution and determination the attempt is renewed1 but only to be followed with a repetition of the seizure1 until the unhappy sufferer ceases from sheer dread to try to quench the thirst which torments him4 ,indeed the very thought of doing so suffices to bring on a choking paroxysm1 as does also the sound of the running of water4 ,the patient is extremely sensitive to any kind of external impression2 a bright light1 a loud noise1 a breath of cool air1 contact with any one1 are all apt to bring on one of these seizures4 ,but besides these suffocative attacks there also occur general convulsions affecting the whole muscular system of the body1 and occasionally a condition of tetanic spasm4 ,these various paroxysms increase in frequency and severity with the advance of the disease1 but alternate with intervals of comparative quiet1 in which1 however1 there is intense anxiety and more or less constant difficulty of breathing1 accompanied with a peculiar sonorous expiration1 which has suggested the notion that the patient barks like a dog4 ,in many instances there is great mental disturbance1 with fits of maniacal excitement1 in which he strikes at every one about him1 and accuses them of being the cause of his sufferings--these attacks being succeeded by calm intervals in which he expresses great regret for his violent behaviour4 ,during all this stage of the disease the patient is tormented with a viscid secretion accumulating in his mouth1 which from dread of swallowing he is constantly spitting about him4 ,there may also be noticed snapping movements of the jaws as if he were attempting to bite1 but these are in reality a manifestation of the spasmodic action which affects the muscles generally4 ,there is no great amount of fever1 but there is constipation1 diminished flow of urine1 and often sexual excitement4 ,after two or three days of suffering of the most terrible description the patient succumbs1 death taking place either in a paroxysm of choking1 or on the other hand in a tranquil manner from exhaustion1 all the symptoms having abated1 and the power of swallowing returned before the end4 ,the duration of the disease from the first declaration of the symptoms is generally from three to five days4 ,apart from the inoculation method 7see below71 the treatment of most avail is that which is directed towards preventing the absorption of the poison into the system4 ,this may be accomplished by excision of the part involved in the bite of the rabid animal1 or1 where this from its locality is impracticable1 in the application to the wound of some chemical agent which will destroy the activity of the virus1 such as potassa fusa1 lunar caustic 7nitrate of silver71 or the actual cautery in the form of a red-hot wire4 ,the part should be thoroughly acted on by these agents1 no matter what amount of temporary suffering this may occasion4 ,such applications should be resorted to immediately after the bite has been inflicted1 or as soon thereafter as possible4 ,further1 even though many hours or days should elapse1 these local remedies should still be applied2 for if1 as appears probable1 some at least of the virus remains for long at the injured part1 the removal or effectual destruction of this may prevent the dread consequences of its absorption4 ,every effort should be made to tranquillize and reassure the patient4 ,two special points of interest have arisen in recent years in connexion with this disease4 ,one is the ,pasteur treatment by inoculation with rabic virus 7see also ,,parasitic ,,diseases71 and the other was the attempt of the government to exterminate rabies in the ,british ,isles by muzzling dogs4 ,pasteur treatment4 ,the ,pasteur treatment was first applied to human beings in #ahhe after prolonged investigation and experimental trial on animals4 ,it is based on the fact that a virus1 capable of giving rabies by inoculation1 can be extracted from the tissues of a rabid animal and then intensified or attenuated at pleasure4 ,it appears that the strength of the rabic virus1 as determined by inoculation1 is constant in the same species of animal1 but is modified by passing through another species4 ,for instance1 the natural virus of dogs is always of the same strength1 but when inoculated into monkeys it becomes weakened1 and the process of attenuation can be carried on by passing the virus through a succession of monkeys1 until it loses the power of causing death4 ,if this weakened virus is then passed back through guinea-pigs1 dogs or rabbits1 it regains its former strength4 ,again1 if it be passed through a succession of dogs it becomes intensified up to a maximum of strength which is called the virus fixe4 ,pasteur further discovered that the strength can be modified by temperature and by keeping the dried tissues of a rabid animal containing the virus4 ,thus1 if the spinal cord of a rabid dog be preserved in a dry state1 the virus loses strength day by day4 ,the system of treatment consists in making an emulsion of the cord and graduating the strength of the dose by using a succession of cords1 which have been kept for a progressively diminishing length of time4 ,those which have been kept for fourteen days are used as a starting-point1 yielding virus of a minimum strength4 ,they are followed by preparations of diminishing age and increasing strength1 day by day1 up to the maximum1 which is three days old4 ,these are successively injected into the circulatory system4 ,the principle is the artificial acquisition by the patient of resistance to the rabic virus1 which is presumed to be already in the system but has not yet become active1 by accustoming him gradually to its toxic effect1 beginning with a weak form and progressively increasing the dose4 ,it is not exactly treatment of the disease1 because it is useless or nearly so when the disease has commenced1 nor is it exactly preventive1 for the patient has already been bitten4 ,it must be regarded as a kind of anticipatory cure4 ,the cords are cut into sections and preserved dry in sterilized flasks plugged with cotton-wool4 ,another method of preparing the inoculatory virus1 which has been devised by ,guido ,tizzoni and ,eugenio ,centanni1 consists in subjecting the virus fixe to peptic digestion by diluted gastric juice for varying periods of time4 ,the first patient was treated by ,pasteur's system in ,july #ahhe4 ,he was successively inoculated with emulsions made from cords that had been kept fourteen and ten days1 then eleven and eight days1 then eight1 seven1 six days1 and so on4 ,two forms of treatment are now used--7#a7 the simple1 in which the course from weak to strong virus is extended over nine days2 7#b7 the intensive1 in which the maximum is reached in seven days4 ,the latter is used in cases of very bad bites and those of some standing1 in which it is desirable to lose no time4 ,two days are compressed into one at the commencement by making injections morning and evening instead of once a day1 so that the fifth-day cord is reached in four days instead of six1 as in the simple treatment4 ,when the maximum--the third-day cord--is reached the injections are continued with fifth-1 fourth-1 and third-day cords4 ,the whole course is fifteen days in the simple treatment and twenty-one in the intensive4 ,the doses injected range from #a to #c cubic centimetres4 ,injections are made alternately into the right and left flanks4 ,the following table shows the number treated from #ahhf to #aije1 with the mortality4 ------------------------------ ,year4,patients,deaths4,mortality ,treated4 per cent4 ------------------------------ #ahhf #bfga #be 4#id #ahhg #aggj #ad 4#gi #ahhh #afbb #i 4#ee #ahhi #ahcj #g 4#ch #ahij #aedj #e 4#cb #ahia #aeei #d 4#be #ahib #agij #d 4#bb #ahic #afdh #f 4#cf #ahid #achg #g 4#ej #ahie #aebj #e 4#cc #ahif #acjh #d 4#cj #ahig #aeba #f 4#ci #ahih #adfe #c 4#bj #ahii #afad #d 4#be #aijj #adai #aj 4#gj #aija #acah #e 4#cg #aijb #aaje #b 4#ah #aijc #fcj #d 4#fe #aijd #geg #e 4#ff #aije #gbg #d 4#ed ------------------------------ ,these figures do not include cases which develop hydrophobia during treatment or within fifteen days after treatment is completed1 for it is held that persons who die within that period have their nervous centres invaded by virus before the cure has time to act4 ,the true mortality should therefore be considerably higher4 ,for instance1 in #ahih three deaths came within this category1 which just doubles the mortality2 and in #ahii the additional deaths were six1 bringing the mortality up to two-and-a-half times that indicated in the table4 ,when1 however1 the additional deaths are included the results remain sufficiently striking1 if two assumptions are granted--7#a7 that all the persons treated have been bitten by rabid animals2 7#b7 that a large proportion of persons so bitten usually have hydrophobia4 ,unfortunately1 both these assumptions lack proof1 and therefore the evidence of the efficacy of the treatment cannot be said to satisfy a strictly scientific standard4 ,with regard to the first point1 the patients are divided into three categories--7#a7 those bitten by an animal the rabidity of which is proved by the development of rabies in other animals bitten by it or inoculated from its spinal cord2 7#b7 those bitten by an animal pronounced rabid on a veterinary examination2 7#c7 those bitten by an animal suspected of being rabid4 ,the number of patients in each category in #ahih was 7#a7 #ada1 7#b7 #hee1 7#c7 #dfi2 and in #ahii it was 7#a7 #aeb1 7#b7 #ajii1 7#c7 #cfc4 ,as might be expected1 the vast majority came under the second and third heads1 in which the evidence of rabidity is doubtful or altogether lacking4 ,with regard to the second point1 the proportion of persons bitten by rabid animals who ordinarily develop hydrophobia has only been estimated from very inadequate data4 ,otto ,bollinger from a series of collected statistics states that before the introduction of the ,pasteur treatment1 of patients bitten by dogs undoubtedly rabid #dg died1 the rate being #cc in those whose wounds had been cauterized and #hc when there had been no local treatment4 ,if the number of rabid dogs be compared with the deaths from hydrophobia in any year or series of years1 it can hardly be very high4 ,for instance1 in #ahie1 #ffh dogs1 besides other animals1 were killed and certified to be rabid in ,england1 and the deaths from hydrophobia were twenty4 ,of course this proves nothing1 as the number of persons bitten is not known1 but the difference between the amount of rabies and of hydrophobia is suggestively great in view of the marked propensity of rabid dogs to bite1 nor is it accounted for by the fact that some of the persons bitten were treated at the ,institut ,pasteur4 ,a comparison of the annual mortality from hydrophobia in ,france before and after the introduction of the treatment would afford decisive evidence as to its efficacy2 but unfortunately no such comparison can be made for lack of vital statistics in that country4 ,the experience of the ,paris hospitals1 however1 points to a decided diminution of mortality4 ,on the whole it must be said1 in the absence of further data1 that the ,pasteur treatment certainly diminishes the danger of hydrophobia from the bites of rabid animals4 ,more recently treatment with an anti-rabic serum has been suggested 7see ,,parasitic ,,diseases74 ,victor ,babes and ,lepp and later ,guido ,tizzoni and ,eugenio ,centanni have worked out a method of serum treatment curative and protective4 ,in this method not the rabic poison itself1 as in the ,pasteur treatment1 but the protective substance formed is injected into the tissues4 ,the serum of a vaccinated animal is capable of neutralizing the power of the virus of rabies not only when mixed with the virus before injection but even when injected simultaneously or within twenty-four hours after the introduction of the virus4 ,these authors showed that the serum of a rabbit protects a rabbit better than does the serum of a dog1 and vice versa4 ,at the end of twenty days' injections they found they could obtain such a large quantity of anti-rabic substance in the serum of an animal1 that even #a part of serum to #be1jjj of the body weight would protect an animal4 ,this process differs from that of ,pasteur in so far as that in place of promoting the formation of the antidote within the body of the patient1 by a process of vaccination with progressively stronger and stronger virus1 this part of the process is carried on in an animal1 ,babes using the dog and ,centanni the sheep1 the blood serum of which is injected4 ,this method of vaccination is useful as a protective to those in charge of kennels4 ,muzzling order in ,england4 ,the attempt to stamp out rabies in ,great ,britain was an experiment undertaken by the government in the public interest4 ,the principal means adopted were the muzzling of dogs in infected areas1 and prolonged quarantine for imported animals4 ,the efficacy of dog-muzzling in checking the spread of rabies and diminishing its prevalence has been repeatedly proved in various countries4 ,liable as other animals may be to the disease1 in ,england at least the dog is pre-eminently the vehicle of contagion and the great source of danger to human beings4 ,there is a difference of opinion on the way in which muzzling acts1 though there can be none as to the effect it produces in reducing rabies4 ,probably it acts rather by securing the destruction of ownerless and stray--which generally includes rabid--dogs than by preventing biting2 for though it may prevent snapping1 even the wire-cage muzzle does not prevent furious dogs from biting1 and it is healthy1 not rabid1 dogs that wear the muzzle4 ,it has therefore been suggested that a collar would have the same effect1 if all collarless dogs were seized2 but the evidence goes to show that it has not1 perhaps because rabid dogs are more likely to stray from home with their collars1 which are constantly worn1 than with muzzles which are not1 and so escape seizure4 ,moreover1 it is much easier for the police to see whether a dog is wearing a muzzle or not than it is to make sure about the collar4 ,however this may be1 the muzzle has proved more efficacious1 but it was not applied systematically in ,england until a late date4 ,sometimes the regulations were in the hands of the government1 and sometimes they were left to local authorities2 in either case they were allowed to lapse as soon as rabies had died down4 ,in ,april #ahig the ,board of ,agriculture entered on a systematic attempt to exterminate rabies by the means indicated4 ,the plan was to enforce muzzling over large areas in which the disease existed1 and to maintain it for six months after the occurrence of the last case4 ,in spite of much opposition and criticism1 this was resolutely carried out under ,mr ,walter ,long1 the responsible minister1 and met with great success4 ,by the spring of #ahii--that is1 in two years--the disease had disappeared in ,great ,britain1 except for one area in ,wales2 and1 with this exception1 muzzling was everywhere relaxed in ,october #ahii4 ,it was taken off in ,wales also in the following ,may1 no case having occurred since ,november #ahii4 ,rabies was then pronounced extinct4 ,during the summer of #aijj1 however1 it reappeared in ,wales1 and several counties were again placed under the order4 ,the year #aija was the third in succession in which no death from hydrophobia was registered in the ,united ,kingdom4 ,in the ten years preceding #ahii1 #ajd deaths were registered1 the death-rate reaching #cj in #ahhi and averaging #bi annually4 ,in #aijb two deaths from hydrophobia were registered4 ,from that date to ,june #aiji 7the latest available for the purpose of this article7 no death from hydrophobia was notified in the ,united ,kingdom4 ,see ,annales de l',institut ,pasteur1 from #ahhf2 ,journal of the ,board of ,agriculture1 #ahii2 ,makins1 ,hydrophobia1 in ,treves's ,system of ,surgery2 ,woodhead1 ,rabies1 in ,allbutt's ,system of ,medicine4 ,,hydrosphere 7,gr4 ,greek3 hydr1 water1 and ,greek3 sphaira1 sphere71 in physical geography1 a name given to the whole mass of the water of the oceans1 which fills the depressions in the earth's crust1 and covers nearly three-quarters of its surface4 ,the name is used in distinction from the atmosphere1 the earth's envelope of air1 the lithosphere 7,gr4 ,greek3 lithos1 rock7 or solid crust of the earth1 and the centrosphere or interior mass within the crust4 ,to these spheres some writers add1 by figurative usage1 the terms biosphere1 or life-sphere1 to cover all living things1 both animals and plants1 and psychosphere1 or mind-sphere1 covering all the products of human intelligence4 ,,hydrostatics 7,gr4 ,greek3 hydr1 water1 and the root ,greek3 sta-1 to cause to stand71 the branch of hydromechanics which discusses the equilibrium of fluids 7see ,,hydromechanics74 ,,hydroxylamine1 ,,nh#b,,oh1 or hydroxy-ammonia1 a compound prepared in #ahfe by ,w4 ,c4 ,lossen by the reduction of ethyl nitrate with tin and hydrochloric acid4 ,in #ahgj ,e4 ,ludwig and ,t4 ,h4 ,hein 7,chem4 ,centralblatt1 #ahgj1 #a1 p4 #cdj7 obtained it by passing nitric oxide through a series of bottles containing tin and hydrochloric acid1 to which a small quantity of platinum tetrachloride has been added2 the acid liquid is poured off when the operation is completed1 and sulphuretted hydrogen is passed in2 the tin sulphide is filtered off and the filtrate evaporated4 ,the residue is extracted by absolute alcohol1 which dissolves the hydroxylamine hydrochloride and a little ammonium chloride2 this last substance is removed as ammonium platino-chloride1 and the residual hydroxylamine hydrochloride is recrystallized4 ,e4 ,divers obtains it by mixing cold saturated solutions containing one molecular proportion of sodium nitrate1 and two molecular proportions of acid sodium sulphite1 and then adding a saturated solution of potassium chloride to the mixture4 ,after standing for twenty-four hours1 hydroxylamine potassium disulphonate crystallizes out4 ,this is boiled for some hours with water and the solution cooled1 when potassium sulphate separates first1 and then hydroxylamine sulphate4 ,e4 ,tafel 7,zeit4 anorg4 ,chem41 #aijb1 #ca1 p4 #bhi7 patented an electrolytic process1 wherein #ej sulphuric acid is treated in a divided cell provided with a cathode of amalgamated lead1 #ej nitric acid being gradually run into the cathode compartment4 ,pure anhydrous hydroxylamine has been obtained by ,c4 ,a4 ,lobry de ,bruyn from the hydrochloride1 by dissolving it in absolute methyl alcohol and then adding sodium methylate4 ,the precipitated sodium chloride is filtered1 and the solution of hydroxylamine distilled in order to remove methyl alcohol1 and finally fractionated under reduced pressure4 ,the free base is a colourless1 odourless1 crystalline solid1 melting at about #cj ,c41 and boiling at #eh ,c4 7under a pressure of #bb mm474 ,it deliquesces and oxidizes on exposure1 inflames in dry chlorine and is reduced to ammonia by zinc dust4 ,its aqueous solution is strongly alkaline1 and with acids it forms well-defined stable salts4 ,e4 ,ebler and ,e4 ,schott 7,j4 pr4 ,chem41 #aijh1 #gh1 p4 #bhi7 regard it as acting with the formula ,,nh#b,,oh towards bases1 and as ,,nh#c3,o towards acids1 the salts in the latter case being of the oxonium type4 ,it is a strong reducing agent1 giving a precipitate of cuprous oxide from alkaline copper solutions at ordinary temperature1 converting mercuric chloride to mercurous chloride1 and precipitating metallic silver from solutions of silver salts4 ,with aldehydes and ketones it forms oximes 7q4v474 ,w4 ,r4 ,dunstan 7,jour4 ,chem4 ,soc41 #ahii1 #ge1 p4 #gib7 found that the addition of methyl iodide to a methyl alcohol solution of hydroxylamine resulted in the formation of trimethyloxamine1 ,n7,,ch#c7c,o4 ,many substituted hydroxylamines are known1 substitution taking place either in the alpha or beta position beta alpha 7,,nh#b ,,oh74 beta-phenylhydroxyl-amine1 ,c#f;,h#e,,nh,,oh1 is obtained in the reduction of nitrobenzene in neutral solution 7e4g4 by the action of the aluminium-mercury couple and water71 but better1 according to ,c4 ,goldschmidt 7,ber41 #ahif1 #bi1 p4 #bcjg7 by dissolving nitrobenzene in ten times its weight of ether containing a few cubic centimetres of water1 and heating with excess of zinc dust and anhydrous calcium chloride for three hours on a water bath4 ,it also appears as an intermediate product in the electrolytic reduction of nitrobenzene in sulphuric acid solution4 ,by gentle oxidation it yields nitrosobenzene4 ,derivatives of the type ,r#b,n,,oh result in the action of the ,grignard reagent on amyl nitrite4 ,dihydroxy-ammonia or nitroxyl1 ,,nh7,,oh7#b1 a very unstable and highly reactive substance1 has been especially studied by ,a4 ,angeli 7see ,a4 ,w4 ,stewart1 ,recent ,advances in ,physical and ,inorganic ,chemistry1 #aiji74 ,,hydrozoa1 one of the most widely spread and prolific groups of aquatic animals4 ,they are for the most part marine in habitat1 but a familiar fresh-water form is the common ,hydra of ponds and ditches1 which gives origin to the name of the class4 ,the ,hydrozoa comprise the hydroids1 so abundant on all shores1 most of which resemble vegetable organisms to the unassisted eye2 the hydrocorallines1 which1 as their name implies1 have a massive stony skeleton and resemble corals2 the jelly-fishes so called2 and the ,siphonophora1 of which the species best known by repute is the so-called ,portuguese man-of-war 7,physalia71 dreaded by sailors on account of its terrible stinging powers4 ,in external form and appearance the ,hydrozoa exhibit such striking differences that there would seem at first sight to be little in common between the more divergent members of the group4 ,nevertheless there is no other class in the animal kingdom with better marked characteristics1 or with more uniform morphological peculiarities underlying the utmost diversity of superficial characters4 ,all ,hydrozoa1 in the first place1 exhibit the three structural features distinctive of the ,coelentera 7q4v474 7#a7 ,the body is built up of two layers only1 an external protective and sensory layer1 the ectoderm1 and an internal digestive layer1 the endoderm4 7#b7 ,the body contains but a single internal cavity1 the coelenteron or gastrovascular space1 which may be greatly ramified1 but is not shut off into cavities distinct from the central digestive space4 7#c7 ,the generative cells are produced in either the ectoderm or endoderm1 and not in a third layer arising in the embryo1 distinct from the two primary layers2 in other words1 there is no mesoderm or coelom4 ,to these three characters the ,hydrozoa add a fourth which is distinctive of the subdivision of the ,coelenterata termed the ,cnidaria2 that is to say1 they always possess peculiar stinging organs known as nettle-cells1 or nematocysts 7,cnidae71 each produced in a cell forming an integral part of the animal's tissues4 ,the ,hydrozoa are thus shown to belong to the group of ,coelenterata ,cnidaria1 and it remains to consider more fully their distinctive features1 and in particular those which mark them off from the other main division of the ,cnidaria1 the ,anthozoa 7q4v471 comprising the corals and sea-anemones4 ,the great diversity1 to which reference has already been made1 in the form and structure of the ,hydrozoa is due to two principal causes4 ,in the first place1 we find in this group two distinct types of person or individual1 the polyp and the medusa 7qq4v471 each capable of a wide range of variations2 and when both polyp and medusa occur in the life-cycle of the same species1 as is frequently the case1 the result is an alternation of generations of a type peculiarly characteristic of the class4 ,in the second place1 the power of non-sexual reproduction by budding is practically of universal occurrence among the ,hydrozoa1 and by the buds failing to separate from the parent stock1 colonies are produced1 more or less complicated in structure and often of great size4 ,we find that polyps may either bud other polyps or may produce medusae1 and that medusae may bud medusae1 though never1 apparently1 polyps4 ,hence we have a primary subdivision of the colonies of ,hydrozoa into those produced by budding of polyps and those produced by budding of medusae4 ,the former may contain polyp-persons and medusa-persons1 either one kind alone or both kinds combined2 the latter will contain only medusa-persons variously modified4 ,the morphology of the ,hydrozoa reduces itself1 therefore1 to a consideration of the morphology of the polyp1 of the medusa and of the colony4 ,putting aside the last-named1 for a detailed account of which see ,,hydromedusae1 we can best deal with the peculiarities of the polyp and medusa from a developmental point of view4 ,in the development of the ,hydrozoa1 and indeed of the ,cnidaria generally1 the egg usually gives rise to an oval larva which swims about by means of a coating of cilia on the surface of the body4 ,this very characteristic larva is termed a planula1 but though very uniform externally1 the planulae of different species1 or of the same species at different periods1 do not always represent the same stage of embryonic development internally4 ,on examining more minutely the course of the development1 it is found that the ovum goes through the usual process of cleavage1 always total and regular in this group1 and so gives rise to a hollow sphere or ovoid with the wall composed of a single layer of cells1 and containing a spacious cavity1 the blastocoele or segmentation-cavity4 ,this is the blastula stage occurring universally in all ,metazoa1 probably representing an ancestral ,protozoan colony in phylogeny4 ,next the blastula gives rise to an internal mass of cells 7fig4 #a1 hy7 which come from the wall either by immigration 7fig4 #a1 ,a7 or by splitting off 7delamination74 ,the formation of an inner cell-mass converts the single-layered blastula 7monoblastula7 into a double-layered embryo 7diblastula7 which may be termed a parenchymula1 since at first the inner cell-mass forms an irregular parenchyma which may entirely fill up and obliterate the segmentation cavity 7fig4 #a1 ,b74 ,at a later stage1 however1 the cells of the inner mass arrange themselves in a definite layer surrounding an internal cavity 7fig4 #a1 ,c1 al71 which soon acquires an opening to the exterior at one pole1 and so forms the characteristic embryonic stage of all ,enterozoa known as the gastrula 7fig4 #b74 ,in this stage the body is composed of two layers1 ectoderm 7d7 externally1 and endoderm 7c7 internally1 surrounding a central cavity1 the archenteron 7b71 which communicates with the exterior by a pore 7a71 the blastopore4 ,thus a planula larva may be a blastula1 or but slightly advanced beyond this stage1 or it may be 7and most usually is7 a parenchymula2 or in some cases 7,scyphomedusae7 it may be a gastrula4 ,it should be added that the process of development1 the gastrulation as it is termed1 may be shortened by the immigration of cells taking place at one pole only1 and in a connected layer with orderly arrangement1 so that the gastrula stage is reached at once from the blastula without any intervening parenchymula stage4 ,this is a process of gastrulation by invagination which is found in all animals above the ,coelenterata1 but which is very rare in the ,cnidaria1 and is known only in the ,scyphomedusae amongst the ,hydrozoa4 ,illustration3 ,from ,balfour1 after ,kowalewsky4 ,,fig4 #a4--;,formation of the ,diblastula of ,eucope 7one of the ,calyptoblastic ,hydromedusae7 by immigration4 ,a1 ,b1 ,c1 three successive stages4 ep1 ,ectoderm2 hy1 endoderm2 al1 enteric cavity4 ,after the gastrula stage1 which is found as a developmental stage in all ,enterozoa1 the embryo of the ,hydrozoa proceeds to develop characters which are peculiar to the ,coelenterata only4 ,round the blastopore hollow outgrowths1 variable in number1 arise by the evagination of the entire body-wall1 both ectoderm and endoderm4 ,each outgrowth contains a prolongation of the archenteric cavity 7compare figs4 #b and #c1 ,a74 ,in this way is formed a ring of tentacles1 the most characteristic organs of the ,cnidaria4 ,they surround a region which is termed the peristome1 and which contains in the centre the blastopore1 which becomes the adult mouth4 ,the archenteron becomes the gastrovascular system or coelenteron4 ,between the ectoderm and endoderm a gelatinous supporting layer1 termed the mesogloea1 makes its appearance4 ,the gastrula has now become an actinula1 which may be termed the distinctive larva of the ,cnidaria1 and doubtless represents in a transitory manner the common ancestor of the group4 ,in no case known1 however1 does the actinula become the adult1 sexually mature individual1 but always undergoes further modifications1 whereby it develops into either a polyp or a medusa4 ,illustration3 ,from ,gegenbaur's ,elements of ,comparative ,anatomy4 ,,fig4 #b4--;,diagram of a ,diblastula4 a1 ,blastopore4 b1 ,archenteric cavity4 c1 ,endoderm4 d1 ,ectoderm4 ,to become a polyp1 the actinula 7fig4 #c1 ,a7 becomes attached to some firm object by the pole farthest from the mouth1 and its growth preponderates in the direction of the principal axis1 that is to say1 the axis passing through the mouth 7fig4 #c1 a-b74 ,as a result the body becomes columnar in form 7fig4 #c1 ,b71 and without further change passes into the characteristic polyp-form 7see ,,polyp74 ,illustration3 ,,fig4 #c4--;,diagram showing the change of the ,actinula 7,a7 into a ,polyp 7,b72 a-b1 principal 7vertical7 axis2 c-d1 horizontal axis4 ,the endoderm is shaded1 the ectoderm is left clear4 ,it is convenient to distinguish two types of polyp by the names hydro polyp and anthopolyp1 characteristic of the ,hydrozoa and ,anthozoa respectively4 ,in the hydropolyp the body is typically elongated1 the height of the column being far greater than the diameter4 ,the peristome is relatively small and the mouth is generally raised on a projecting spout or hypostome4 ,the ectoderm loses entirely the ciliation which it had in the planula and actinula stages and commonly secretes on its external surface a protective or supporting investment1 the perisarc4 ,contrasting with this1 the anthopolyp is generally of squat form1 the diameter often exceeding the height2 the peristome is wide1 a hypostome is lacking1 and the ectoderm1 or so much of it as is exposed1 i4e4 not covered by secretion of skeletal or other investment1 retains its ciliation throughout life4 ,the internal structural differences are even more characteristic4 ,in the hydropolyp the blastopore of the embryo forms the adult mouth situated at the extremity of the hypostome1 and the ectoderm and endoderm meet at this point4 ,in the anthopolyp the blastopore is carried inwards by an in-pushing of the body-wall of the region of the peristome1 so that the adult mouth is an opening leading into a short ectodermal oesophagus or stomodaeum1 at the bottom of which is the blastopore4 ,further1 in the hydropolyp the digestive cavity either remains simple and undivided and circular in transverse section1 or may show ridges projecting internally1 which in this case are formed of endoderm alone1 without any participation of the mesogloea4 ,in the anthopolyp1 on the other hand1 the digestive cavity is always subdivided by so-called mesenteries1 in-growths of the endoderm containing vertical lamellae of mesogloea 7see ,,anthozoa74 ,in short1 the hydropolyp is characterized by a more simple type of organization than the anthopolyp1 and is in most respects less modified from the actinula type of structure4 ,illustration3 ,,fig4 #d4--;,diagram showing the change of the ,actinula into a ,medusa4 ,a1 ,vertical section of the actinula2 a-b and c-d as in fig4 #c1 ,b1 transitional stage1 showing preponderating growth in the horizontal plane4 ,c1 ,c'1 ,d1 ,d'1 two types of medusa organization2 ,c and ,d are composite sections1 showing a radius 7,r7 on one side1 an interradius 7,,ir7 on the other2 ,c' and ,d' are plans2 the mouth and manubrium are indicated at the centre1 leading into the gastral cavity subdivided by the four areas of concrescence in each interradius 7,,ir74 t1 tentacle2 g4p1 gastric pouch2 r4c1 radial canal not present in ,c and ,c'2 c4c1 circular or ring-canal2 e4l1 endoderm-lamella formed by concrescence4 ,for a more detailed diagram of medusa-structure see article ,,medusa4 ,returning now to the actinula1 this form may1 as already stated1 develop into a medusa1 a type of individual found only in the ,hydrozoa1 as here understood4 ,to become a medusa1 the actinula grows scarcely at all in the direction of the principal axis1 but greatly along a plane at right angles to it4 ,thus the body becomes umbrella-shaped1 the concave side representing the peristome1 and the convex side the column1 of the polyp4 ,hence the tentacles are found at the edge of the umbrella1 and the hypostome forms usually a projecting tube1 with the mouth at the extremity1 forming the manubrium or handle of the umbrella4 ,the medusa has a pronounced radial symmetry1 and the positions of the primary tentacles1 usually four in number1 mark out the so-called radii1 alternating with which are four interradii4 ,the ectoderm retains its ciliation only in the sensory organs4 ,the mesogloea becomes enormously increased in quantity 7hence the popular name jelly-fish71 and in correlation with this the endoderm-layer lining the coelenteron becomes pressed together in the interradial areas and undergoes concrescence1 forming a more or less complicated gastrovascular system 7see ,,medusa74 ,it is sufficient to state here that the medusa is usually a free-swimming animal1 floating mouth downwards on the open seas1 but in some cases it may be attached by its aboral pole1 like a polyp1 to some firm basis1 either temporarily or permanently4 ,thus the development of the two types of individual seen in the ,hydrozoa may be summarized as follows3-- _/ ,egg ,free ,blastula ,planula ,parenchymula ,stage ,gastrula ,actinula _/ _/ ,polyp ,medusa ,this development1 though probably representing the primitive sequence of events1 is never actually found in its full extent1 but is always abbreviated by omission or elimination of one or more of the stages4 ,we have already seen that the parenchymula stage is passed over when the gastrulation is of the invaginate type4 ,on the other hand1 the parenchymula may develop directly into the actinula or even into the polyp1 with suppression of the intervening steps4 ,great apparent differences may also be brought about by variations in the period at which the embryo is set free as a larva1 and since two free-swimming stages1 planula and actinula1 are unnecessary1 one or other of them is always suppressed4 ,a good example of this is seen in two common genera of ,british hydroids1 ,cordylophora and ,tabularia4 ,in ,cordylophora the embryo is set free at the parenchymula stage as a planula which fixes itself and develops into a polyp1 both gastrula and actinula stages being suppressed4 ,in ,tubularia1 on the other hand1 the parenchymula develops into an actinula within the maternal tissues1 and is then set free1 creeps about for a time1 and after fixing itself1 changes into a polyp2 hence in this case the planula-stage1 as a free larva1 is entirely suppressed4 ,the ,hydrozoa may be defined1 therefore1 as ,cnidaria in which two types of individual1 the polyp and the medusa1 may be present1 each type developed along divergent lines from the primitive actinula form4 ,the polyp 7hydropolyp7 is of simple structure and never has an ectodernal oesophagus or mesenteries4#a ,the general ectoderm loses its cilia1 which persist only in the sensory cells1 and it frequently secretes external protective or supporting structures4 ,an internal mesogloeal skeleton is not found4 ,the class is divisible into two main divisions or sub-classes1 ,hydromedusae and ,scyphomedusae1 of which definitions and detailed systematic accounts will be found under these headings4 ,,general ,,works ,,on ,,hydrozoa4--,c4 ,chun1 ,coelenterata 7,hohlthiere71 ,bronn's ,klassen und ,ordnungen des ,thier-,reichs ii4 #b 7#ahhi et seq472 ,y4 ,delage1 and ,e4 ,hrouard1 ,trait de zoologie concrte1 ii4 part #b1 ,les ,coelentrs 7#aija72 ,g4 ,h4 ,fowler1 ,the ,hydromedusae and ,scyphomedusae in ,e4 ,r4 ,lankester's ,treatise on ,zoology1 ii4 chapters iv4 and v4 7#aijj72 ,s4 ,j4 ,hickson1 ,coelenterata and ,ctenophora1 ,cambridge ,natural ,history1 i4 chapters x4-xv4 7#aijf74 7,e4 ,a4 ,m47 ,,footnote3 #a ,see further under ,,scyphomedusae4 ,,hyena1 a name applicable to all the representatives of the mammalian family ,hyaenidae1 a group of ,carnivora 7q4v47 allied to the civets4 ,from all other large ,carnivora except the ,african hunting-dog1 hyenas are distinguished by having only four toes on each foot1 and are further characterized by the length of the fore-legs as compared with the hind pair1 the non-retractile claws1 and the enormous strength of the jaws and teeth1 which enables them to break the hardest bones and to retain what they have seized with unrelaxing grip4 ,illustration3 ,,fig4 #a4--,the ,striped ,hyena 7,hyaena striata74 ,illustration3 ,,fig4 #b4--,the ,spotted ,hyena 7,hyaena crocuta74 ,the striped hyena 7,hyaena striata7 is the most widely distributed species1 being found throughout ,india1 ,persia1 ,asia ,minor1 and ,north and ,east ,africa1 the ,east ,african form constituting a distinct race1 ,h4 striata schillingsi2 while there are also several distinct ,asiatic races4 ,the species resembles a wolf in size1 and is greyish-brown ,in colour1 marked with indistinct longitudinal stripes of a darker hue1 while the legs are transversely striped4 ,the hairs on the body are long1 especially on the ridge of the neck and back1 where they form a distinct mane1 which is continued along the tail4 ,nocturnal in habits1 it prefers by day the gloom of caves and ruins1 or of the burrows which it occasionally forms1 and issues forth at sunset1 when it commences its unearthly howling4 ,when the animal is excited1 the howl changes into what has been compared to demoniac laughter1 whence the name of laughing-hyena4 ,these creatures feed chiefly on carrion1 and thus perform useful service by devouring remains which might otherwise pollute the air4 ,even human dead are not safe from their attacks1 their powerful claws enabling them to gain access to newly interred bodies in cemeteries4 ,occasionally 7writes ,dr ,w4 ,t4 ,blanford7 sheep or goats1 and more often dogs1 are carried off1 and the latter1 at all events1 are often taken alive to the animal's den4 ,this species appears to be solitary in habits1 and it is rare to meet with more than two together4 ,the cowardice of this hyena is proverbial2 despite its powerful teeth1 it rarely attempts to defend itself4 ,a very different animal is the spotted hyena1 ,hyaena 7,crocuta7 crocuta1 which has the sectorial teeth of a more cat-like type1 and is marked by dark-brown spots on a yellowish ground1 while the mane is much less distinct4 ,at the ,cape it was formerly common1 and occasionally committed great havoc among the cattle1 while it did not hesitate to enter the ,kaffir dwellings at night and carry off children sleeping by their mothers4 ,by persistent trapping and shooting1 its numbers have now been considerably reduced1 with the result1 however1 of making it exceedingly wary1 so that it is not readily caught in any trap with which it has had an opportunity of becoming acquainted4 ,its range extends from ,abyssinia to the ,cape4 ,the ,abyssinian form has been regarded as a distinct species1 under the name of ,h4 liontiewi1 but this1 like various more southern forms1 is but regarded as a local race4 ,the brown hyena 7,h4 brunnea7 is ,south ,african1 ranging to ,angola on the west and ,kilimanjaro on the east4 ,in size it resembles the striped hyena1 but differs in appearance1 owing to the fringe of long hair covering the neck and fore part of the back4 ,the general hue is ashy-brown1 with the hair lighter on the neck 7forming a collar71 chest and belly2 while the legs are banded with dark brown4 ,this species is not often seen1 as it remains concealed during the day4 ,those frequenting the coast feed on dead fish1 crabs and an occasional stranded whale1 though they are also a danger to the sheep and cattle kraal4 ,strand-wolf is the local name at the ,cape4 ,although hyenas are now confined to the warmer regions of the ,old ,world1 fossil remains show that they had a more northerly range during ,tertiary times2 the ,european cave-hyena being a form of the spotted species1 known as ,h4 crocuta spelaea4 ,fossil hyenas occur in the ,lower ,pliocene of ,greece1 ,china1 ,india1 c42 while remains indistinguishable from those of the striped species have been found in the ,upper ,pliocene of ,england and ,italy4 ,,hy,,res1 a town in the department of the ,var in ,s4,e4 ,france1 #aa m4 by rail ,e4 of ,toulon4 ,in #aijf the population of the commune was #ag1gij1 of the town #aj1dfd2 the population of the former was more than doubled in the last decade of the #aith century4 ,hyres is celebrated 7as is also its fashionable suburb1 ,costebelle1 nearer the seashore7 as a winter health resort4 ,the town proper is situated about #b m4 from the seashore1 and on the south-western slope of a steep hill 7#ffi ft41 belonging to the ,maurettes chain1 #ifa ft471 which is one of the westernmost spurs of the thickly wooded ,montagnes des ,maures4 ,it is sheltered from the north-east and east winds1 but is exposed to the cold north-west wind or mistral4 ,towards the south and south-east a fertile plain1 once famous for its orange groves1 but now mainly covered by vineyards and farms1 stretches to the sea1 while to the south-west1 across a narrow valley1 rises a cluster of low hills1 on which is the suburb of ,costebelle4 ,the older portion of the town is still surrounded1 on the north and east1 by its ancient1 though dilapidated medieval walls1 and is a labyrinth of steep and dirty streets4 ,the more modern quarter which has grown up at the southern foot of the hill has handsome broad boulevards and villas1 many of them with beautiful gardens1 filled with semi-tropical plants4 ,among the objects of interest in the old town are3 the house 7,rue ,rabaton1 #g7 where ,j4 ,b4 ,massillon 7#affc-agdb71 the famous pulpit orator1 was born2 the parish church of ,st ,louis1 built originally in the #acth century by the ,cordelier or ,franciscan friars1 but completely restored in the earlier part of the #aith century2 and the site of the old chteau1 on the summit of the hill1 now occupied by a villa4 ,the plain between the new town and the sea is occupied by large nurseries1 an excellent jardin d'acclimatation1 and many market gardens1 which supply ,paris and ,london with early fruits and vegetables1 especially artichokes1 as well as with roses in winter4 ,there are extensive salt beds 7salines7 both on the peninsula of ,giens1 ,s4 of the town1 and also ,e4 of the town4 ,to the east of the ,giens peninsula is the fine natural harbour of ,hyres1 as well as three thinly populated islands 7the ,stoechades of the ancients71 ,porquerolles1 ,port ,cros and ,le ,levant1 which are grouped together under the common name of les d',hyres4 ,the town of ,hyres seems to have been founded in the #ajth century1 as a place of defence against pirates1 and takes its name from the aires 7hierbo in the ,provenal dialect71 or threshing-floors for corn1 which then occupied its site4 ,it passed from the possession of the viscounts of ,marseilles to ,charles of ,anjou1 count of ,provence1 and brother of ,st ,louis 7the latter landed here in #abed1 on his return from ,egypt74 ,the chteau was dismantled by ,henri ,,iv41 but thanks to its walls1 the town resisted in #agjg an attack made by the duke of ,savoy4 ,see ,ch4 ,lenthric1 ,la ,provence ,maritime ancienne et moderne 7chap4 #e7 7,paris1 #ahhj74 7,w4 ,a4 ,b4 ,c47 ,,hygieia1 in ,greek mythology1 the goddess of health4 ,it seems probable that she was originally an abstraction1 subsequently personified1 rather than an independent divinity of very ancient date4 ,the question of the original home of her worship has been much discussed4 ,the oldest traces of it1 so far as is known at present1 are to be found at ,titane in the territory of ,sicyon1 where she was worshipped together with ,asclepius1 to whom she appears completely assimilated1 not an independent personality4 ,her cult was not introduced at ,epidaurus till a late date1 and therefore1 when in #dbj ,b4,c4 the worship of ,asclepius was introduced at ,athens coupled with that of ,hygieia1 it is not to be inferred that she accompanied him from ,epidaurus1 or that she is a ,peloponnesian importation at all4 ,it is most probable that she was invented at the time of the introduction of ,asclepius1 after the sufferings caused by the plague had directed special attention to sanitary matters4 ,the already existing worship of ,athena ,hygieia had nothing to do with ,hygieia the goddess of health1 but merely denoted the recognition of the power of healing as one of the attributes of ,athena1 which gradually became crystallized into a concrete personality4 ,at first no special relationship existed between ,asclepius and ,hygieia1 but gradually she came to be regarded as his daughter1 the place of his wife being already secured by ,epione4 ,later ,orphic hymns1 however1 and ,herodas iv4 #a-i1 make her the wife of ,asclepius4 ,the cult of ,hygieia then spread concurrently with that of ,asclepius1 and was introduced at ,rome from ,epidaurus in #bic1 by which time she may have been admitted 7which was not the case before7 into the ,epidaurian family of the god4 ,her proper name as a ,romanized ,greek importation was ,valetudo1 but she was gradually identified with ,salus1 an older genuine ,italian divinity1 to whom a temple had already been erected in #cjb4 ,while in classical times ,asclepius and ,hygieia are simply the god and goddess of health1 in the declining years of paganism they are protecting divinities generally1 who preserve mankind not only from sickness but from all dangers on land and sea4 ,in works of art ,hygieia is represented1 together with ,asclepius1 as a maiden of benevolent appearance1 wearing the chiton and giving food or drink to a serpent out of a dish4 ,see the article by ,h4 ,lechat in ,daremberg and ,saglio's ,dictionnaire des antiquits1 with full references to authorities2 and ,e4 ,thrmer in ,roscher's ,lexikon der ,mythologie1 with a special section on the modern theories of ,hygieia4 ,,hygiene 7,fr4 hygine1 from ,gr4 ,greek3 hygiainein1 to be healthy71 the science of preserving health1 its practical aim being to render growth more perfect1 decay less rapid1 life more vigorous1 death more remote4 ,the subject is thus a very wide one1 embracing all the agencies which affect the physical and mental well-being of man1 and it requires acquaintance with such diverse sciences as physics1 chemistry1 geology1 engineering1 architecture1 meteorology1 epidemiology1 bacteriology and statistics4 ,on the personal or individual side it involves consideration of the character and quality of food and of water and other beverages2 of clothing2 of work1 exercise and sleep2 of personal cleanliness1 of special habits1 such as the use of tobacco1 narcotics1 c42 and of control of sexual and other passions4 ,in its more general and public aspects it must take cognizance of meteorological conditions1 roughly included under the term climate2 of the site or soil on which dwellings are placed2 of the character1 materials and arrangement of dwellings1 whether regarded individually or in relation to other houses among which they stand2 of their heating and ventilation2 of the removal of excreta and other effete matters2 of medical knowledge relating to the incidence and prevention of disease2 and of the disposal of the dead4 ,these topics will be found treated in such articles as ,,dietetics1 ,,food1 ,,food-,,preservation1 ,,adulteration1 ,,water1 ,,heating1 ,,ventilation1 ,,sewerage1 ,,bacteriology1 ,,housing1 ,,cremation1 c4 ,for legal enactments which concern the sanitary well-being of the community1 see ,,public ,,health4 ,,hyginus1 eighth pope4 ,it was during his pontificate 7c4 #acg-adj7 that the gnostic heresies began to manifest themselves at ,rome4 ,,hyginus 7surnamed ,,gromaticus1 from gruma1 a surveyor's measuring-rod71 ,latin writer on land-surveying1 flourished in the reign of ,trajan 7,a4,d4 #ih-aag74 ,fragments of a work on legal boundaries attributed to him will be found in ,c4 ,f4 ,lachmann1 ,gromatici ,veteres1 i4 7#ahdh74 ,a treatise on ,castrametation 7,de ,munitionibus ,castrorum71 also attributed to him1 is probably of later date1 about the #crd century ,a4,d4 7ed4 ,w4 ,gemoll1 #ahgi2 ,a4 von ,domaszewski1 #ahhg74 ,,hyginus1 ,,gaius ,,julius1 ,latin author1 a native of ,spain 7or ,alexandria71 was a pupil of the famous ,cornelius ,alexander ,polyhistor and a freedman of ,augustus1 by whom he was made superintendent of the ,palatine library 7,suetonius1 ,de ,grammaticis1 #bj74 ,he is said to have fallen into great poverty in his old age1 and to have been supported by the historian ,clodius ,licinus4 ,he was a voluminous author1 and his works included topographical and biographical treatises1 commentaries on ,helvius ,cinna and the poems of ,virgil1 and disquisitions on agriculture and bee-keeping4 ,all these are lost4 ,under the name of ,hyginus two school treatises on mythology are extant3 7#a7 ,fabularum ,liber1 some #cjj mythological legends and celestial genealogies1 valuable for the use made by the author of the works of ,greek tragedians now lost2 7#b7 ,de ,astronomia1 usually called ,poetica ,astronomica1 containing an elementary treatise on astronomy and the myths connected with the stars1 chiefly based on the ,greek3 ,katasterismoi of ,eratosthenes4 ,both are abridgments and both are by the same hand2 but the style and ,latinity and the elementary mistakes 7especially in the rendering of the ,greek originals7 are held to prove that they cannot have been the work of so distinguished a scholar as ,c4 ,julius ,hyginus4 ,it is suggested that these treatises are an abridgment 7made in the latter half of the #bnd century7 of the ,genealogiae of ,hyginus by an unknown grammarian1 who added a complete treatise on mythology4 ,,editions4--,fabulae1 by ,m4 ,schmidt 7#ahgb72 ,de ,astronomia1 by ,b4 ,bunte 7#ahge72 see also ,bunte1 ,de ,c4 ,julii ,hygini1 ,augusti ,liberti1 ,vita et ,scriptis 7#ahdf74 ,,hygrometer 7,gr4 ,greek3 hygros1 moist1 ,greek3 metron1 a measure71 an instrument for measuring the absolute or relative amount of moisture in the atmosphere2 an instrument which only qualitatively determines changes in the humidity is termed a hygroscope4 ,the earlier instruments generally depended for their action on the contraction or extension of substances when exposed to varying degrees of moisture2 catgut1 hair1 twisted cords and wooden laths1 all of which contract with an increase in the humidity and vice versa1 being the most favoured materials4 ,the familiar weather house exemplifies this property4 ,this toy consists of a house provided with two doors1 through which either a man or woman appears according as the weather is about to be wet or fine4 ,this action is effected by fixing a catgut thread to the base on which the figures are mounted1 in such a manner that contraction of the thread rotates the figures so that the man appears and extension so that the woman appears4 ,many of the early forms are described in ,c4 ,hutton1 ,math4 and ,phil4 ,dictionary 7#ahae74 ,the modern instruments1 which utilize other principles1 are described in ,,meteorology3 ,,ii4 ,methods and ,apparatus4 ,,hyksos1 or ,,shepherd ,,kings1 the name of the earliest invaders of ,egypt of whom we have definite evidence in tradition4 ,josephus 7c4 ,apion4 i4 #ad71 who identifies the ,hyksos with the ,israelites1 preserves a passage from the second book of ,manetho giving an account of them4 7,it may be that ,josephus had it1 not direct from ,manetho's writings1 but through the garbled version of some ,alexandrine compiler47 ,in outline it is as follows4 ,in the days of a king of ,egypt named ,timaeus the land was suddenly invaded from the east by men of ignoble race1 who conquered it without a struggle1 destroyed cities and temples1 and slew or enslaved the inhabitants4 ,at length they elected a king named ,salatis1 who1 residing at ,memphis1 made all ,egypt tributary1 and established garrisons in different parts1 especially eastwards1 fearing the ,assyrians4 ,he built also a great fortress at ,avaris1 in the ,sethroite nome1 east of the ,bubastite branch of the ,nile4 ,salatis was followed in succession by ,beon1 ,apachnas1 ,apophis1 ,jannas and ,asses4 ,these six kings reigned #aih years and #aj months1 and all aimed at extirpating the ,egyptians4 ,their whole race was named ,hyksos1 i4e4 shepherd kings1 and some say they were ,arabs 7another explanation found by ,josephus is captive shepherds74 ,when they and their successors had held ,egypt for #eaa years1 the kings of the ,thebais and other parts of ,egypt rebelled1 and a long and mighty war began4 ,misphragmuthosis worsted the ,shepherds and shut them up in ,avaris2 and his son ,thutmosis1 failing to capture the stronghold1 allowed them to depart2 whereupon they went forth1 #bdj1jjj in number1 established themselves in ,judea and built ,jerusalem4 ,in ,manetho's list of kings1 the six above named 7with many variations in detail7 form the ,x,vth dynasty1 and are called six foreign ,phoenician kings4 ,the ,x,v,ith dynasty is of thirty-two ,hellenic 7sic87 shepherd kings1 the seventeenth is of shepherds and ,theban kings 7reigning simultaneously74 ,the lists vary greatly in different versions1 but the above seems the most reasonable selection of readings to be made4 ,for ,hellenic see below4 ,the supposed connexion with the ,israelites has made the problem of the ,hyksos attractive1 but light is coming upon it very slowly4 ,in #ahdg ,e4 de ,roug proved from a fragment of a story in the papyri of the ,british ,museum1 that ,apopi was one of the latest of the ,hyksos kings1 corresponding to ,aphobis2 he was king of the pest and suppressed the worship of the ,egyptian gods1 and endeavoured to make the ,egyptians worship his god ,setekh or ,seti2 at the same time an ,egyptian named ,seqenenre reigned in ,thebes1 more or less subject to ,aphobis4 ,the city of ,hawari 7,avaris7 was also mentioned in the fragment4 ,in #ahej a record of the capture of this city from the ,hyksos by ,ahmosi1 the founder of the eighteenth dynasty1 was discovered by the same scholar4 ,a large class of monuments was afterwards attributed to the ,hyksos1 probably in error4 ,some statues and sphinxes1 found in #ahfa by ,mariette at ,tanis 7in the north-east of the ,delta71 which had been usurped by later kings1 had peculiar un-,egyptian features4 ,one of these bore the name of ,apopi engraved lightly on the shoulder2 this was evidently a usurper's mark1 but from the whole circumstances it was concluded that these1 and others of the same type of features found elsewhere1 must have belonged to the ,hyksos4 ,this view held the field until #ahic1 when ,golnischeff produced an inferior example bearing its original name1 which showed that in this case it represented ,amenemhe ,,iii4 ,in consequence it is now generally believed that they all belong to the twelfth dynasty4 ,meanwhile a headless statue of a king named ,khyan1 found at ,bubastis1 was attributed on various grounds to the ,hyksos1 the soundest arguments being his foreign name and the boastful un-,egyptian epithet beloved of his ka1 where beloved of ,ptah or some other god was to be expected4 ,his name was immediately afterwards recognized on a lion found as far away from ,egypt as ,bagdad4 ,flinders ,petrie then pointed out a group of kings named on scarabs of peculiar type1 which1 including ,khyan1 he attributed to the period between the ,old ,kingdom and the ,new1 while others were in favour of assigning them all to the ,hyksos1 whose appellation seemed to be recognizable in the title ,hek-khos1 ruler of the barbarians1 borne by ,khyan4 ,the extraordinary importance of ,khyan was further shown by the discovery of his name on a jar-lid at ,cnossus in ,crete4 ,semitic features were pointed out in the supposed ,hyksos names1 and ,petrie was convinced of their date by his excavations of #aije-aijf in the eastern ,delta4 ,avaris is generally assigned to the region towards ,pelusium on the strength of its being located in the ,sethroite nome by ,josephus1 but ,petrie thinks it was at ,tell el-,yahudiyeh 7,yehudia71 where ,hyksos scarabs are common4 ,from the remains of fortifications there he argues that the ,hyksos were uncivilized desert people1 skilled in the use of the bow1 and must thus have destroyed by their archery the ,egyptian armies trained to fight hand-to-hand2 further1 that their hordes were centered in ,syria1 but were driven thence by a superior force in the ,east to take refuge in the islands and became a sea-power--whence the strange description ,hellenic in ,manetho1 which most editors have corrected to ,greek3 alloi1 others4 ,besides the statue of ,khyan1 blocks of granite with the name of ,apopi have been found in ,upper ,egypt at ,gebelen and in ,lower ,egypt at ,bubastis4 ,the celebrated ,rhind mathematical papyrus was copied in the reign of an ,apopi from an original of the time of ,amenemhe ,,iii4 ,large numbers of ,hyksos scarabs are found in ,upper and ,lower ,egypt1 and they are not unknown in ,palestine4 ,khyan's monuments1 inconspicuous as they are1 actually extend over a wider area--from ,bagdad to ,cnossus--than those of any other ,egyptian king4 ,it is certain that this mysterious people were ,asiatic1 for they are called so by the ,egyptians4 ,though ,seth was an ,egyptian god1 as god of the ,hyksos he represents some ,asiatic deity4 ,the possibility of a connexion between the ,hyksos and the ,israelites is still admitted in some quarters4 ,hatred of these impious foreigners1 of which there is some trace in more than one text1 aroused amongst the ,egyptians 7as nothing ever did before or since7 that martial spirit which carried the armies of ,tethmosis to the ,euphrates4 ,besides the histories of ,egypt1 see ,j4 ,h4 ,breasted1 ,ancient ,records of ,egypt2 ,historical ,documents ii4 #d1 #abe2 ,g4 ,maspero1 ,contes populaires1 #cme d4 p4 #bcf2 ,w4 ,m4 ,f4 ,petrie1 ,hyksos and ,israelite ,cities1 p4 #fg2 ,golnischeff in ,recueil de travaux1 xv4 p4 #aca4 7,f4 ,ll4 ,g47 ,,hylas1 ,in ,greek legend1 son of ,theiodamas1 king of the ,dryopians in ,thessaly1 the favourite of ,heracles and his companion on the ,argonautic expedition4 ,having gone ashore at ,kios in ,mysia to fetch water1 he was carried off by the nymphs of the spring in which he dipped his pitcher4 ,heracles sought him in vain1 and the answer of ,hylas to his thrice-repeated cry was lost in the depths of the water4 ,ever afterwards1 in memory of the threat of ,heracles to ravage the land if ,hylas were not found1 the inhabitants of ,kios every year on a stated day roamed the mountains1 shouting aloud for ,hylas 7,apollonius ,rhodius i4 #abjg2 ,theocritus xiii42 ,strabo xii4 #efd2 ,propertius i4 #bj2 ,virgil1 ,ecl4 vi4 #dc74 ,but1 although the legend is first told in ,alexandrian times1 the cry of ,hylas occurs long before as the ,mysian cry in ,aeschylus 7,persae1 #ajed71 and in ,aristophanes 7,plutus1 #aabg7 to cry ,hylas is used proverbially of seeking something in vain4 ,hylas1 like ,adonis and ,hyacinthus1 represents the fresh vegetation of spring1 or the water of a fountain1 which dries up under the heat of summer4 ,it is suggested that ,hylas was a harvest deity and that the ceremony gone through by the ,kians was a harvest festival1 at which the figure of a boy was thrown into the water1 signifying the dying vegetation-spirit of the year4 ,see ,g4 ,trk in ,breslauer ,philologische ,abhandlungen1 vii4 7#ahie72 ,w4 ,mannhardt1 ,mythologische ,forschungen 7#ahhd74 ,,hylozoism 7,gr4 ,greek3 hyl1 matter1 ,greek3 z1 life71 in philosophy1 a term applied to any system which explains all life1 whether physical or mental1 as ultimately derived from matter 7cosmic matter1 ,weldstoff74 ,such a view of existence has been common throughout the history of thought1 and especially among physical scientists4 ,thus the ,ionian school of philosophy1 which began with ,thales1 sought for the beginning of all things in various material substances1 water1 air1 fire 7see ,,ionian ,,school74 ,these substances were regarded as being in some sense alive1 and taking some active part in the development of being4 ,this primitive hylozoism reappeared in modified forms in medieval and ,renaissance thought1 and in modern times the doctrine of materialistic monism is its representative4 ,between modern materialism and hylozoism proper there is1 however1 the distinction that the ancients1 however vaguely1 conceived the elemental matter as being in some sense animate if not actually conscious and conative4 ,,hymen1 or ,,hymenaeus1 originally the name of the song sung at marriages among the ,greeks4 ,as usual the name gradually produced the idea of an actual person whose adventures gave rise to the custom of this song4 ,he occurs often in association with ,linus and ,ialemus1 who represent similar personifications1 and is generally called a son of ,apollo and a ,muse4 ,as the son of ,dionysus and ,aphrodite1 he was regarded as a god of fruitfulness4 ,in ,attic legend he was a beautiful youth who1 being in love with a girl1 followed her in a procession to ,eleusis disguised as a woman1 and saved the whole band from pirates4 ,as reward he obtained the girl in marriage1 and his happy married life caused him ever afterwards to be invoked in marriage songs 7,servius on ,virgil1 ,aen4 i4 #fea74 ,according to another story1 he was a youth who was killed by the fall of his house on his wedding day2 hence he was invoked1 to propitiate him and avert a similar fate from others 7,servius1 loc4 cit474 ,he is represented in works of art as an effeminate-looking1 winged youth1 carrying a bridal torch and wearing a nuptial veil4 ,the marriage song was sung1 with musical accompaniment1 during the procession of the bride from her parents' house to that of the bridegroom1 ,hymenaeus being invoked at the end of each portion4 ,see ,r4 ,schmidt1 ,de ,hymenaeo el ,talasio 7#ahhf71 and ,j4 ,a4 ,hild in ,daremberg and ,saglis's ,dictionnaire des antiquits4 ,,hymenoptera 7,gr4 ,greek3 hymn1 a membrane1 and ,greek3 pteron1 a wing71 a term used in zoological classification for one of the most important orders of the class ,hexapoda 7q4v474 ,the order was founded by ,linnaeus 7,systema ,naturae1 #agce71 and is still recognized by all naturalists in the sense proposed by him1 to include the saw-flies1 gall-flies1 ichneumon-flies and their allies1 ants1 wasps and bees4 ,the relationship of the ,hymenoptera to other orders of insects is discussed in the article ,,hexapoda1 but it may be mentioned here that in structure the highest members of the order are remarkably specialized1 and that in the perfection of their instincts they stand at the head of all insects and indeed of all invertebrate animals4 ,about #cj1jjj species of ,hymenoptera are now known4 ,illustration3 ,after ,c4 ,l4 ,marlatt1 ,bur4 ,ent4 ,bull4 #c1 ,n4,s41 ,u4,s4 ,dept4 ,agric4 ,,fig4 #a4--;,a1 ,front of head of ,saw-fly 7,pachynematus72 a1 labrum2 b1 clypeus2 c1 vertex2 d1 d1 antennal cavities4 ,c and ,d1 ,mandibles4 ,e1 ,first maxilla2 a1 cardo2 b1 stipes2 c1 galea2 d1 lacinia2 e1 palp4 ,b1 ,second maxillae 7,labium72 a1 mentum2 b1 ligula 7between the two galeae72 c1 c1 palps4 ,magnified4 ,illustration3 ,,fig4 #b4--;,jaws of ,hive-bee 7,apis mellifica74 ,magnified about #f times4 a1 mandible2 b1 c1 palp and lacinia of first maxilla2 d1 e1 g1 h1 mentum1 palp1 fused laciniae 7ligula or tongue7 and galea of #bnd maxillae4 ,illustration3 ,after ,c4 ,janet1 ,mem4 ,soc4 ,zool4 ,france 7#ahih74 ,,fig4 #c4--,median section through mid-body of female ,red ,ant 7,myrmica rubra74 ,h1 ,head2 #a1 #b1 #c1 the thoracic segments2 i41 ii41 the first and second abdominal segments2 i41 being the propodeum4 ,characters4--,in all ,hymenoptera the mandibles 7fig4 #a1 ,c1 ,d7 are well developed1 being adapted1 as in the more lowly winged insects1 such as the ,orthoptera1 for biting4 ,the more generalized ,hymenoptera have the second maxillae but slightly modified1 their inner lobes being fused to form a ligula 7fig4 #a1 ,b1 b74 ,in the higher families this structure becomes elongated 7fig4 #b1 g7 so as to form an elaborate sucking-organ or tongue4 ,these insects are able1 therefore1 to bite as well as to suck1 whereas most insects which have acquired the power of suction have lost that of biting4 ,both fore- and hind-wings are usually present1 both pairs being membranous1 the hind-wings small and not folded when at rest1 each provided along the costa with a row of curved hooks which catch on to a fold along the dorsum of the adjacent fore-wing during flight4 ,a large number of ,hymenoptera are1 however1 entirely wingless--at least as regards one sex or form of the species4 ,one of the most remarkable features is the close union of the foremost abdominal segment 7fig4 #c1 i47 with the metathorax1 of which it often seems to form a part1 the apparent first abdominal segment being1 in such case1 really the second 7fig4 #c1 ii474 ,the true first segment1 which undergoes a more or less complete fusion with the thorax is known as the median segment or propodeum4 ,in female ,hymenoptera the typical insectan ovipositor with its three pairs of processes is well developed1 and in the higher families this organ becomes functional as a sting 7fig4 #e71--used for offence and defence4 ,as regards their life history1 all ,hymenoptera undergo a complete metamorphosis4 ,the larva is soft-skinned 7eruciform71 being either a caterpillar 7fig4 #f1 b7 or a legless grub 7fig4 #g1 a71 and the pupa is free 7fig4 #g1 c71 i4e4 with the appendages not fixed to the body1 as is the case in the pupa of most moths4 ,illustration3 ,,fig4 #d4--;,fore-,wings of ,hymenoptera4 #a4 ,tenthredinidae 7,hylotoma7-- #a1 marginal2 #b1 appendicular2 #c1 #d1 #e1 #f1 radial or submarginal2 #g1 #h1 #i1 median or discoidal2 #aj1 sub-costal2 #aa1 #ab1 cubital or branchial2 and #ac1 anal or lanceolate cellules2 a1 b1 c1 submarginal nervures2 d1 basal nervures2 e1 f1 recurrent nervures2 st1 stigma2 co1 costa4 #b4 ,cynipidae 7,cynips74 #c4 ,chalcididae 7,perilampus74 #d4 ,proctotrypidae 7,codrus74 #e4 ,mymaridae 7,mymar74 #f4 ,braconidae 7,bracon74 #g4 ,ichneumonidae 7,trogus74 #h4 ,chrysididae 7,cleptes74 #i4 ,formicidae 7,formica74 #aj4 ,vespidae 7,vespa74 #aa4 ,apidae 7,apathus74 ,structure4--,the head of a hymenopterous insect bears three simple eyes 7ocelli7 on the front and vertex in addition to the large compound eyes4 ,the feelers are generally simple in type1 rarely showing serrations or prominent appendages2 but one or two basal segments are frequently differentiated to form an elongate scape1 the remaining segments--carried at an elbowed angle to the scape--making up the flagellum2 the segments of the flagellum often bear complex sensory organs4 ,the general characters of the jaws have been mentioned above1 and in detail there is great variation in these organs among the different families4 ,the sucking tongue of the ,hymenoptera has often been compared with the hypopharynx of other insects4 ,according to ,d4 ,sharp1 however1 the hypopharynx is present in all ,hymenoptera as a distinct structure at the base of the tongue1 which must be regarded as representing the fused laciniae of the second maxillae4 ,in the thorax the pronotum and prosternum are closely associated with the mesothorax1 but the pleura of the prothorax are usually shifted far forwards1 so that the fore-legs are inserted just behind the head4 ,a pair of small plates--the tegulae--are very generally present at the bases of the fore-wings4 ,the union of the first abdominal segment with the metathorax has been already mentioned4 ,the second 7so-called first7 abdominal segment is often very constricted1 forming the waist so characteristic of wasps and ants for example4 ,the constriction of this segment and its very perfect articulation with the propodeum give great mobility to the abdomen1 so that the ovipositor or sting can be used with the greatest possible accuracy and effect4 ,mention has already been made of the series of curved hooks along the costa of the hind-wing2 by means of this arrangement the two wings of a side are firmly joined together during flight1 which thus becomes particularly accurate4 ,the wings in the ,hymenoptera show a marked reduction in the number of nervures as compared with more primitive insects4 ,the main median nervure1 and usually also the sub-costal become united with the radial1 while the branches of radial1 median and cubital nervures pursuing a transverse or recurrent course across the wing1 divide its area into a number of areolets or cells1 that are of importance in classification4 ,among many of the smaller ,hymenoptera we find that the wings are almost destitute of nervures4 ,in the hind-wings--on account of their reduced size--the nervures are even more reduced than in the fore-wings4 ,the legs of ,hymenoptera are of the typical insectan form1 and the foot is usually composed of five segments4 ,in many families the trochanter appears to be represented by two small segments1 there being thus an extra joint in the leg4 ,it is almost certain that the distal of these two segments really belongs to the thigh1 but the ordinary nomenclature will be used in the present article1 as this character is of great importance in discriminating families1 and the two segments in question are referred to the trochanter by most systematic writers4 ,illustration3 ,after ,c4 ,janet1 ,aiguillon de la ,myrmica rubra 7,paris1 #ahih74 ,,fig4 #e4--,ovipositor or ,sting of ,red ,ant 7,myrmica rubra7 ,queen4 ,magnified4 ,the right sheath ,c 7outer process of the ninth abdominal segment--#i7 is shown in connexion with the guide ,b formed by the inner processes of the #ith segment4 ,the stylet ,a 7process of the #hth abdominal segment--#h7 is turned over to show its groove a1 which works along the tongue or rail b4 ,the typical insectan ovipositor1 so well developed among the ,hymenoptera1 consists of three pairs of processes 7gonapophyses7 two of which belong to the ninth abdominal segment and one to the eighth4 ,the latter are the cutting or piercing stylets 7fig4 #e1 ,a7 of the ovipositor1 while the two outer processes of the ninth segment are modified into sheaths or feelers 7fig4 #e1 ,c7 and the two inner processes form a guide 7fig4 #e1 ,b7 on which the stylets work1 tongues or rails on the guide fitting accurately into longitudinal grooves on the stylet4 ,in the different families of the ,hymenoptera1 there are various modifications of the ovipositor1 in accord with the habits of the insects and the purposes to which the organ is put4 ,the sting of wasps1 ants and bees is a modified ovipositor and is used for egg-laying by the fertile females1 as well as for defence4 ,most male ,hymenoptera have processes which form claspers or genital armature4 ,these processes are not altogether homologous with those of the ovipositor1 being formed by inner and outer lobes of a pair of structures on the ninth abdominal segment4 ,many points of interest are to be noted in the internal structure of the ,hymenoptera4 ,the gullet leads into a moderate-sized crop1 and several pairs of salivary glands open into the mouth4 ,the crop is followed by a proventriculus which1 in the higher ,hymenoptera1 forms the so-called honey stomach1 by the contraction of whose wails the solid and liquid food can be separated1 passed on into the digestive stomach1 or held in the crop ready for regurgitation into the mouth4 ,behind the digestive stomach are situated1 as usual1 intestine and rectum1 and the number of kidney 7,malpighian7 tubes varies from only six to over a hundred1 being usually great4 ,in the female1 each ovary consists of a large number of ovarian tubes1 in which swollen chambers containing the egg-cells alternate with smaller chambers enclosing nutrient material4 ,in connexion with the ovipositor are two poison-glands1 one acid and the other alkaline in its secretion4 ,the acid gland consists of one1 two or more tubes1 with a cellular coat of several layers1 opening into a reservoir whence the duct leads to the exterior4 ,the alkaline gland is an irregular tube with a single cellular layer1 its duct opening alongside that of the acid reservoir4 ,these glands are most strongly developed when the ovipositor is modified into a sting4 ,development4--,parthenogenesis is of normal occurrence in the life-cycle of many ,hymenoptera4 ,there are species of gall-fly in which males are unknown1 the unfertilized eggs always developing into females4 ,on the other hand1 in certain saw-flies and among the higher families1 the unfertilized eggs1 capable of development1 usually give rise to male insects 7see ,,bee74 ,the larvae of most saw-flies feeding on the leaves of plants are caterpillars 7fig4 #f1 b7 with numerous abdominal pro-legs1 but in most families of ,hymenoptera the egg is laid in such a situation that an abundant food-supply is assured without exertion on the part of the larva1 which is consequently a legless grub1 usually white in colour1 and with soft flexible cuticle 7fig4 #g1 a74 ,the organs and instincts for egg-laying and food-providing are perhaps the most remarkable features in the economy of the ,hymenoptera4 ,gall-fly grubs are provided with vegetable food through the eggs being laid by the mother insect within plant tissues4 ,the ichneumon pierces the body of a caterpillar and lays her eggs where the grubs will find abundant animal food4 ,a digging-wasp hunts for insect prey and buries it with the egg1 while a true wasp feeds her brood with captured insects1 as a bird her fledglings4 ,bees store honey and pollen to serve as food for their young4 ,thus we find throughout the order a degree of care for offspring unreached by other insects1 and this family-life has1 in the best known of the ,hymenoptera--ants1 wasps and bees--developed into an elaborate social organization4 ,social ,life4--,the development of a true insect society among the ,hymenoptera is dependent on a differentiation among the females between individuals with well-developed ovaries 7queens7 whose special function is reproduction2 and individuals with reduced or aborted ovaries 7workers7 whose duty is to build the nest1 to gather food and to tend and feed the larvae4 ,among the wasps the workers may only differ from the queens in size1 and individuals intermediate between the two forms of female may be met with4 ,further1 the queen wasp1 and also the queen humble-bee1 commences unaided the work of building and founding a new nest1 being afterwards helped by her daughters 7the workers7 when these have been developed4 ,in the hive-bee and among ants1 on the other hand1 there are constant structural distinctions between queen and worker1 and the function of the queen bee in a hive is confined to egg-laying1 the labour of the community being entirely done by the workers4 ,many ants possess several different forms of worker1 adapted for special duties4 ,details of this fascinating subject are given in the special articles ,,ant1 ,,bee and ,,wasp 7q4v474 ,habits and ,distribution4--,reference has been already made to the various methods of feeding practised by ,hymenoptera in the larval stage1 and the care taken of or for the young throughout the order leads in many cases to the gathering of such food by the mother or nurse4 ,thus1 wasps catch flies2 worker ants make raids and carry off weak insects of many kinds2 bees gather nectar from flowers and transform it into honey within their stomachs--largely for the sake of feeding the larvae in the nest4 ,the feeding habits of the adult may agree with that of the larva1 or differ1 as in the ease of wasps which feed their grubs on flies1 but eat principally vegetable food themselves4 ,the nest-building habit is similarly variable4 ,digging wasps make simple holes in the ground2 many burrowing bees form branching tunnels2 other bees excavate timber or make their brood-chambers in hollow plant-stems2 wasps work up with their saliva vegetable fibres bitten off tree-bark to make paper2 social bees produce from glands in their own bodies the wax whence their nest-chambers are built4 ,the inquiline habit 7cuckoo-parasitism71 when one species makes use of the labour of another by invading the nest and laying her eggs there1 is of frequent occurrence among ,hymenoptera2 and in some cases the larva of the intruder is not content with taking the store of food provided1 but attacks and devours the larva of the host4 ,most ,hymenoptera are of moderate or small size1 the giants of the order--certain saw-flies and tropical digging-wasps--never reach the bulk attained by the largest beetles1 while the wing-spread is narrow compared with that of many dragon-flies and moths4 ,on the other hand1 there are thousands of very small species1 and the tiny fairy-flies 7,mymaridae71 whose larvae live as parasites in the eggs of various insects1 are excessively minute for creatures of such complex organization4 ,hymenoptera are probably less widely distributed than ,aptera1 ,coleoptera or ,diptera1 but they are to be found in all except the most inhospitable regions of the globe4 ,the order is1 with few exceptions1 terrestrial or aerial in habit4 ,comparatively only a few species are1 for part of their lives1 denizens of fresh water2 these1 as larvae1 are parasitic on the eggs or larvae of other aquatic insects1 the little hymenopteron1 ,polynema natans1 one of the fairy-flies--swims through the water by strokes of her delicate wings in search of a dragon-fly's egg in which to lay her own egg1 while the rare ,agriotypus dives after the case of a caddis-worm4 ,it is of interest that the waters have been invaded by the parasitic group of the ,hymenoptera1 since in number of species this is by far the largest of the order4 ,no group of terrestrial insects escapes their attacks--even larvae boring in wood are detected by ichneumon flies with excessively long ovipositors4 ,not a few cases are known in which a parasitic larva is itself pierced by the ovipositor of a hyperparasite1 and even the offspring of the latter may itself fall a victim to the attack of a tertiary parasite4 ,fossil ,history4--,very little is known of the history of the ,hymenoptera previous to the ,tertiary epoch1 early in which1 as we know from the evidence of many ,oligocene and ,miocene fossils1 all the more important families had been differentiated4 ,fragments of wings from the ,lias and ,oolitic beds have been referred to ants and bees1 but the true nature of these remains is doubtful4 ,classification4--,linnaeus divided the ,hymenoptera into two sections--the ,terebrantia1 whose females possess a cutting or piercing ovipositor1 and the ,aculeata1 in which the female organ is modified into a sting4 ,this nomenclature was adopted by ,p4 ,a4 ,latreille and has been in general use until the present day4 ,a closely similar division of the order results from ,t4 ,hartig's character drawn from the trochanter--whether of two segments or undivided--the groups being termed respectively ,ditrocha and ,monotrocha4 ,but the most natural division is obtained by the separation of the saw-flies as a primitive sub-order1 characterized by the imperfect union of the first abdominal segment with the thorax1 and by the broad base of the abdomen1 so that there is no median constriction or waist1 and by the presence of thoracic legs--usually also of abdominal pro-legs--in the larva4 ,all the other families of ,hymenoptera1 including the gall-flies1 ichneumons and aculeates1 have the first abdominal segment closely united with the thorax1 the second abdominal segment constricted so as to form a narrow stalk or waist1 and legless larvae without a hinder outlet to the food-canal4 ,these two sub-orders are usually known as the ,sessiliventra and ,petioliventra respectively1 but the names ,symphyta and ,apocrita proposed in #ahfg by ,c4 ,gerstaecker have priority1 and should not be replaced4 ,symphyta4 ,this sub-order1 characterized by the sessile1 broad-based abdomen1 whose first segment is imperfectly united with the thorax1 and by the usually caterpillar-like larvae with legs1 includes the various groups of saw-flies4 ,three leading families may be mentioned4 ,the ,cephidae1 or stem saw-flies1 have an elongate pronotum1 a compressed abdomen1 and a single spine on the shin of the fore-leg4 ,the soft1 white larvae have the thoracic legs very small and feed in the stems of various plants4 ,cephus pygmaeus is a well-known enemy of corn crops4 ,the ,siricidae 7wood-wasps7 are large elongate insects also with one spine on each fore-shin1 but with the pronotum closely joined to the mesothorax4 ,the ovipositor is long and prominent1 enabling the female insect to lay her eggs in the wood of trees1 where the white larvae1 whose legs are excessively short1 tunnel and feed4 ,these insects are adorned with bands of black and yellow1 or with bright metallic colours1 and on account of their large size and formidable ovipositors they often cause needless alarm to persons unfamiliar with their habits4 ,the ,tenthredinidae1 or true saw-flies1 are distinguished by two spines on each fore-shin1 while the larvae are usually caterpillars1 with three pairs of thoracic legs1 and from six to eight pairs of abdominal pro-legs the latter not possessing the hooks found on the pro-legs of lepidopterous caterpillars4 ,most saw-fly larvae devour leaves1 and the beautifully serrate processes of the ovipositor are well adapted for egg-laying in plant tissues4 ,some saw-fly larvae are protected by a slimy secretion 7fig4 #f1 c7 and a few live concealed in galls4 ,in the form of the feelers1 the wing-neuration and minor structural details there is much diversity among the saw-flies4 ,they have been usually regarded as a single family1 but ,w4 ,h4 ,ashmead has lately differentiated eleven families of them4 ,apocrita4 ,this sub-order includes the vast majority of the ,hymenoptera1 characterized by the narrowly constricted waist in the adult and by the legless condition of the larva4 ,the trochanter is simple in some genera and divided in others4 ,with regard to the minor divisions of this group1 great difference of opinion has prevailed among students4 ,in his recent classification ,ashmead 7#aija7 recognizes seventy-nine families arranged under eight super-families4 ,the number of species included in this division is enormous1 and the multiplication of families is1 to some extent1 a natural result of increasingly close study4 ,but the distinctions between many of these rest on comparatively slight characters1 and it is likely that the future discovery of new genera may abolish many among such distinctions as may now be drawn4 ,it seems advisable1 therefore1 in the present article to retain the wider conception of the family that has hitherto contented most writers on the ,hymenoptera4 ,ashmead's super-families have1 however1 been adopted as--founded on definite structural characters--they probably indicate relationship more nearly than the older divisions founded mostly on habit4 ,the ,cynipoidea include the gall-flies and their parasitic relations4 ,in the ,chalcidoidea1 ,ichneumonoidea and ,proctotrypoidea will be found nearly all the parasitic ,hymenoptera of older classifications4 ,the ,formicoidea are the ants4 ,the group of ,fossores1 or digging-wasps1 is divided by ,ashmead1 one section forming the ,sphecoidea1 while the other1 together with the ,chrysidae and the true wasps1 make up the ,vespoidea4 ,the ,apoidea consists of the bees only4 ,illustration3 ,after ,marlatt1 ,ent4 ,circ4 #bf1 ,u4,s4 ,dept4 ,agric4 ,,fig4 #f4--;a1 ,pear ,saw-fly 7,eriocampoides limacina72 b1 larva without1 and c1 with its slimy protective coat2 e1 cocoon2 f1 larva before pupation2 g1 pupa1 magnified2 d1 leaves with larvae4 ,illustration3 ,after ,howard1 ,ent4 ,tech4 ,bull4 #e ,u4,s4 ,dept4 ,agric4 ,,fig4 #g4--;,chalcid 7,dibrachys boucheanus71 a hyper-parasite4 a1 ,larva4 d1 ,its head more highly magnified4 b1 ,female fly4 c1 ,pupa of male4 e1 ,feeler4 ,cynipoidea4--,in this division the ovipositor issues from the ventral surface of the abdomen2 the pronotum reaches back to the tegulae2 the trochanter has two segments2 the fore-wing 7fig4 #d1 #b7 has no stigma1 but one or two areolets4 ,the feelers with twelve to fifteen segments are thread-like and straight4 ,all the insects included in this group are small and form two families--the ,cynipidae and the ,figitidae4 ,they are the gall-flies1 many of the species laying eggs in various plant-tissues where the presence of the larva causes the formation of a pathological growth or gall1 always of a definite form and characteristic of the species2 the oak-apple and the bedeguar of the rose are familiar examples4 ,other flies of this group have the inquiline habit1 laying their eggs in the galls of other species1 while others again pierce the cuticle of maggots or aphids1 in whose bodies their larvae live as parasites4 ,chalcidoidea4--,this division resembles the ,cynipoidea in the position of the ovipositor1 and in the two segmented trochanters4 ,the fore-wing also has no stigma1 and the whole wing is almost destitute of nervures and areolets1 while the pronotum does not reach back to the tegulae1 and the feelers are elbowed 7fig4 #g74 ,the vast majority of this group1 including nearly #ejjj known species1 are usually reckoned as a single family1 the ,chalcididae1 comprising small insects1 often of bright metallic colours1 whose larvae are parasitic in insects of various orders4 ,the fig-insects1 whose presence in ripening figs is believed essential to the proper development of the fruit1 belong to ,blastophaga and other genera of this family4 ,they are remarkable in having wingless males and winged females4 ,the polyembryonic development of an ,encyrtus1 as studied by ,p4 ,marchal1 is highly remarkable4 ,the female lays her egg in the egg of a small ermine moth 7,hyponomeuta7 and the egg gives rise not to a single embryo but to a hundred1 which develop as the host-caterpillar develops1 being found at a later stage within the latter enveloped in a flexible tube4 ,the ,mymaridae or fairy-flies are distinguished from the ,chalcididae by their narrow fringed wings 7figs4 #d1 #e7 and by the situation of the ovipositor just in front of the tip of the abdomen4 ,they are among the most minute of all insects and their larvae are probably all parasitic in insects' eggs4 ,illustration3 ,after ,riley and ,howard1 ,insect ,life1 vol4 i4 ,,fig4 #h4--;,ichneumon ,fly 7,rhyssa per-suasoria7 ovipositing4 ,ichneumonoidea4--,the ten thousand known species included in this group agree with the ,cynipoidea and ,chalcidoidea in the position of the ovipositor and in the jointed trochanters1 but are distinguished by the fore-wing possessing a distinct stigma and usually a typical series of nervures and areolets 7figs4 #d1 #h74 ,many of the species are of fair size4 ,they lay their eggs 7fig4 #h7 in the bodies of insects and their larvae belonging to various orders4 ,a few small families such as the ,evaniidae and the ,stephanidae are included here1 but the vast majority of the group fall into two large families1 the ,ichneumonidae and the ,braconidae1 the former distinguished by the presence of two median 7or discoidal7 cells in the fore-wing 7figs4 #d1 #g71 while the latter has only one 7figs4 #d1 #f74 ,not a few of these insects1 however1 are entirely wingless4 ,on account of their work in destroying plant-eating insects1 the ichneumon-flies are of great economic importance4 ,proctotrypoidea4--,this group may be distinguished from the preceding by the position of the ovipositor at the extreme apex of the abdomen1 and from the groups that follow 7with very few exceptions7 by the jointed trochanters of the legs4 ,the pronotum reaches back to the tegulae4 ,the ,pelecinidae--included here by ,ashmead--are large insects with remarkably elongate abdomens and undivided trochanters4 ,all the other members of the group may be regarded as forming a single family--the ,proctotrypidae1 including an immense number of small parasitic ,hymenoptera1 not a few of which are wingless4 ,of special interest are the transformations of ,platygaster1 belonging to this family1 discovered by ,m4 ,ganin1 and familiarized to ,english readers through the writings of ,sir ,j4 ,lubbock 7,lord ,avebury74 ,the first larva is broad in front and tapers behind to a tail provided with two divergent processes1 so that it resembles a small crustacean4 ,it lives in the grub of a gall-midge and it ultimately becomes changed into the usual white and fleshy hymenopterous larva4 ,the four succeeding sections1 in which the ovipositor is modified into a sting 7always exserted from the tip of the abdomen7 and the trochanters are with few exceptions simple1 form the ,aculeata of ,linnaeus4 ,formicoidea4--,the ants which form this group are readily distinguished by the differentiation of the females into winged queens and wingless workers4 ,the pronotum extends back to the wing-bases1 and the waist is greatly constricted and marked by one or two nodes4 ,the differentiation of the females leads to a complex social life1 the nesting habits of ants and the various industries that they pursue being of surpassing interest 7see ,,ant74 ,vespoidea4--,this section includes a number of families characterized by the backward extension of the prothorax to the tegulae and distinguished from the ants by the absence of nodes at the base of the abdomen4 ,the true wasps have the fore-wings folded lengthwise when at rest and the fore-legs of normal build--not specialized for digging4 ,the ,vespidae or social wasps have queens and workers like the ants1 but both these forms of female are winged2 the claws on their fret are simple4 ,in the ,eumenidae or solitary wasps the female sex is undifferentiated1 and the foot claws are toothed4 7,for the habits of these insects see ,,wasp47 ,the ,chrysididae or ruby wasps are small insects with a very hard cuticle exhibiting brilliant metallic colours--blue1 green and crimson4 ,only three or four abdominal segments are visible1 the hinder segments being slender and retracted to form a telescope-like tube in which the ovipositor lies4 ,when the ovipositor is brought into use this tube is thrust out4 ,the eggs are laid in the nests of various bees and wasps1 the chrysid larva living as a cuckoo parasite4 ,the ,trigonalidae1 a small family whose larvae are parasitic in wasps' nests1 also probably belong here4 ,the other families of the ,vespoidea belong to the series of ,fossores or digging-wasps4 ,in two of the families--the ,mutillidae and ,thynnidae--the females are wingless and the larvae live as parasites in the larvae of other insects2 the female ,mutilla enters bumble-bees' nests and lays her eggs in the bee-grubs4 ,in the other families both sexes are winged1 and the instinct and industry of the females are among the most wonderful in the ,hymenoptera4 ,they make burrows wherein they place insects or spiders which they have caught and stung1 laying their eggs beside the victim so that the young larvae find themselves in presence of an abundant and appropriate food-supply4 ,valuable observations on the habits of these insects are due to ,j4 ,h4 ,fabre and ,g4 ,w4 and ,e4 ,peckham4 ,the prey is sometimes stung in the neighbourhood of the nerve ganglia1 so that it is paralysed but not killed1 the grub of the fossorial wasp devouring its victim alive2 but this instinct varies in perfection1 and in many cases the larva flourishes equally whether its prey be killed or not4 ,the females have a wonderful power of finding their burrows on returning from their hunting expeditions4 ,among the ,vespoid families of fossorial wasps1 the ,pompilidae are the most important4 ,they are recognizable by their slender and elongate hind-legs2 many of them provision their burrows with spiders4 ,the ,sapygidae are parasitic on bees1 while the ,scoliidae are large1 robust and hairy insects1 many of which prey upon the grubs of chafers4 ,sphecoidea4--,in this division are included the rest of the digging-wasps1 distinguished from the ,vespoidea by the short pronotum not reaching backward to the tegulae4 ,they have usually been reckoned as forming a single1 very large family--the ,sphegidae--but ten or twelve subdivisions of the group are regarded as distinct families by ,ashmead and others4 ,great diversity is shown in the details of structure1 habits and nature of the prey4 ,species of ,sphex1 studied by ,fabre1 provisioned their brood-chambers with crickets4 ,pelopoeus hunts spiders1 while ,ammophila catches caterpillars for the benefit of her young4 ,fabre states that the last-named insect uses a stone for the temporary closing of her burrow1 and the ,peckhams have seen a female ,ammophila take a stone between her mandibles and use it as a hammer for pounding down the earth over her finished nest4 ,the habits of ,bembex are of especial interest4 ,the female1 instead of provisioning her burrow with a supply of food that will suffice the larva for its whole life1 brings fresh flies with which she regularly feeds her young4 ,in this instinct we have a correspondence with the habits of social wasps and bees4 ,yet it may be thought that the usual instinct of the digging-wasps to capture and store up food in an underground burrow for the benefit of offspring which they will never see is even more surprising4 ,the habit of some genera is to catch the prey before making their tunnel1 but more frequently the insect digs her nest1 and then hunts for prey to put into it4 ,apoidea4--,the bees which make up this group agree with the ,sphecoidea in the short pronotum1 but may be distinguished from all other ,hymenoptera by the widened first tarsal segment and the plumose hairs on head and body4 ,they are usually regarded as forming a single family--the ,apidae--but there is very great diversity in structural details1 and ,ashmead divides them into fourteen families4 ,the tongue1 for example1 is short and obtuse or emarginate in ,colletes and ,prosopis1 while in all other bees it is pointed at the tip4 ,but in ,andrena and its allies it is comparatively short1 while in the higher genera1 such as ,apis and ,bombus1 it is elongate and flexible1 forming a most elaborate and perfect organ for taking liquid food4 ,bees feed on honey and pollen4 ,most of the genera are solitary in habit1 the female sex being undifferentiated2 but among the humble-bees and hive-bees we find1 as in social wasps and ants1 the occurrence of workers1 and the consequent elaboration of a wonderful insect-society4 7,see ,,bee47 ,,bibliography4--,the literature of several special families of the ,hymenoptera will be found under the articles ,,ant1 ,,bee1 ,,ichneumon-,,fly1 ,,wasp1 c41 referred to above4 ,among earlier students on structure may be mentioned ,p4 ,a4 ,latreille1 ,familles naturelles du rgne animal 7,paris1 #ahbe71 who recognized the nature of the median segment4 ,c4 ,gerstaecker 7,arch4 f4 ,naturg4 xx41 #ahfg7 and ,f4 ,brauer 7,sitzb4 ,k4 ,akad4 ,wiss4 ,wien4 lxxxv41 #ahhc7 should also be consulted on this subject4 ,for internal anatomy1 specially the digestive organs1 see ,l4 ,dufour1 ,mm4 savants trangers1 vii4 7#ahda71 and ,ann4 ,sci4 ,nat4 ,zool4 7#d71 i4 #ahed4 ,for nervous system ,h4 ,viallanes1 ,ann4 ,sci4 ,nat4 ,zool4 7#g71 ii4 iv4 #ahhf-ahhg1 and ,f4 ,c4 ,kenyon1 ,journ4 ,comp4 ,neurol4 vi41 #ahif4 ,for poison and other glands1 see ,l4 ,bordas1 ,ann4 ,sci4 ,nat4 ,zool4 7#g7 xix41 #ahie4 ,for the sting and ovipositor ,h4 ,dewitz1 ,zeits4 wiss4 ,zool4 xxv41 #ahgd1 xxviii41 #ahgg1 and ,f4 ,zander1 ib4 lxvi41 #ahii4 ,for male genital armature ,s4 ,a4 ,peytoureau1 ,morphologie de l'armure gnitale des insectes 7,bordeaux1 #ahie71 and ,e4 ,zander1 ,zeits4 wiss4 ,zool4 lxvii41 #aijj4 ,the systematic student of ,hymenoptera is greatly helped by ,c4 ,g4 de ,dalla ,torre's ,catalogus ,hymenopterorum 7#aj vols41 ,leipzig1 #ahic-aijb74 ,for general classifications see ,f4 ,w4 ,konow1 ,entom4 ,nachtr4 7#ahig71 and ,w4 ,h4 ,ashmead1 ,proc4 ,u4,s4 ,nat4 ,mus4 xxiii41 #aija2 the latter paper deals also especially with the ,ichneumonoidea of the globe4 ,for habits and life histories of ,hymenoptera see ,j4 ,lubbock 7,lord ,avebury71 ,ants1 ,bees and ,wasps 7#ith ed41 ,london1 #ahhi72 ,c4 ,janet1 tudes sur les fourmis1 les gupes et les abeilles 7,paris1 c41 #ahic and onwards72 and ,g4 ,w4 and ,e4 ,g4 ,peckham1 ,instincts and ,habits of ,solitary ,wasps 7,madison1 ,wis4 ,u4,s4,a41 #ahih74 ,monographs of most of the families of ,british ,hymenoptera have now been published4 ,for saw-flies and gall-flies1 see ,p4 ,cameron's ,british ,phytophagous ,hymenoptera 7#d vols41 ,london1 ,roy4 ,soc41 #ahhb-ahic74 ,for ,ichneumonoidea1 ,c4 ,morley's ,ichneumons of ,great ,britain 7,plymouth1 #aijc1 c471 and ,t4 ,a4 ,marshall's ,british ,braconidae1 ,trans4 ,entom4 ,soc41 #ahhe-ahii4 ,the smaller parasitic ,hymenoptera have been neglected in this country since ,a4 ,h4 ,haliday's classical papers ,entom4 ,mag4 i4-v41 7#ahcc-ahch7 but ,ashmead's ,north ,american ,proctotrypidae 7,bull4 ,u4,s4 ,nat4 ,mus4 xlv41 #ahic7 is valuable for the ,european student4 ,for the ,fossores1 wasps1 ants and bees see ,e4 ,saunders1 ,hymenoptera ,aculeata of the ,british ,islands 7,london1 #ahif74 ,exhaustive references to general systematic works will be found in de ,dalla ,torre's ,catalogue mentioned above4 ,of special value to ,english students are ,c4 ,t4 ,bingham's ,fauna of ,british ,india1 ,hymenoptera 7,london1 #ahig and onwards71 and ,p4 ,cameron's volumes on ,hymenoptera in the ,biologia ,centrali-,americana4 ,f4 ,smith's ,catalogues of ,hymenoptera in the ,british ,museum 7,london1 #ahec-ahei7 are well worthy of study4 7,g4 ,h4 ,c47 ,,hymettus 7,ital4 ,monte ,matto1 hence the modern name ,trello ,vouni71 a mountain in ,attica1 bounding the ,athenian plain on the ,s4,e4 ,height1 #ccgj ft4 ,it was famous in ancient times for its bees1 which gathered honey of peculiar flavour from its aromatic herbs2 their fame still persists4 ,the spring mentioned by ,ovid 7,ars ,amat4 iii4 #fhg7 is probably to be recognized near the monastery of ,syriani or ,kaesariani on the western slope4 ,this may be identical with that known as ,greek3 ,kyllon ,pra1 said to be a remedy for barrenness in women4 ,the marble of ,hymettus1 which often has a bluish tinge1 was used extensively for building in ancient ,athens1 and also1 in early times1 for sculpture2 but the white marble of ,pentelicus was preferred for both purposes4 ,see ,e4 ,dodwell1 ,classical and ,topographical ,tour 7#ahai71 i4 #dhc4 ,,hymns4--#a4 ,classical ,hymnody4--,the word hymn 7,greek3 hymnos7 was employed by the ancient ,greeks#a to signify a song or poem composed in honour of gods1 heroes or famous men1 or to be recited on some joyful1 mournful or solemn occasion4 ,polymnia was the name of their lyric muse4 ,homer makes ,alcinous entertain ,odysseus with a hymn of the minstrel ,demodocus1 on the capture of ,troy by the wooden horse4 ,the ,works and ,days of ,hesiod begins with an invocation to the ,muses to address hymns to ,zeus1 and in his ,theogonia he speaks of them as singing or inspiring hymns to all the divinities1 and of the bard as their servant1 hymning the glories of men of old1 and of the gods of ,olympus4 ,pindar calls by this name odes1 like his own1 in praise of conquerors at the public games of ,greece4 ,the ,athenian dramatists 7,euripides most frequently7 use the word and its cognate verbs in a similar manner2 they also describe by them metrical oracles and apophthegms1 martial1 festal and hymeneal songs1 dirges and lamentations or incantations of woe4 ,hellenic hymns1 according to this conception of them1 have come down to us1 some from a very early and others from a late period of ,greek classical literature4 ,those which passed by the name of ,homer#b were already old in the time of ,thucydides4 ,they are mythological poems 7several of them long71 in hexameter verse--some very interesting4 ,that to ,apollo contains a traditionary history of the origin and progress of the ,delphic worship2 those on ,hermes and on ,dionysus are marked by much liveliness and poetical fancy4 ,hymns of a like general character1 but of less interest 7though these also embody some fine poetical traditions of the ,greek mythology1 such as the story of ,teiresias1 and that of the wanderings of ,leto71 were written in the #crd century before ,christ1 by ,callimachus of ,cyrene4 ,cleanthes1 the successor of ,zeno1 composed 7also in hexameters7 an excellent and devout hymn 7as it is justly called by ,cudworth1 in his ,intellectual ,system7 to ,zeus1 which is preserved in the ,eclogae of ,stobaeus1 and from which ,aratus borrowed the words1 ,for we are also ,his offspring1 quoted by ,st ,paul at ,athens4 ,the so-called ,orphic hymns1 in hexameter verse1 styled ,greek3 teletai1 or hymns of initiation into the mysteries of the ,hellenic religion1 are productions of the ,alexandrian school1--as to which learned men are not agreed whether they are earlier or later than the ,christian era4 ,the ,romans did not adopt the word hymn2 nor have we many ,latin poems of the classical age to which it can properly be applied4 ,there are1 however1 a few--such as the simple and graceful ,dianae sumus in fide 7,dian's votaries are we7 of ,catullus1 and ,dianam tenerae dicite virgines 7,sing to ,dian1 gentle maidens7 of ,horace--which approach much more nearly than anything ,hellenic to the form and character of modern hymnody4 #b4 ,hebrew ,hymnody4--,for the origin and idea of ,christian hymnody we must look1 not to ,gentile1 but to ,hebrew sources4 ,st ,augustine's definition of a hymn1 generally accepted by ,christian antiquity1 may be summed up in the words1 praise to ,god with song 7cum cantico72 ,bede understood the canticum as properly requiring metre2 though he thought that what in its original language was a true hymn might retain that character in an unmetrical translation4 ,modern use has enlarged the definition2 ,roman ,catholic writers extend it to the praises of saints2 and the word now comprehends rhythmical prose as well as verse1 and prayer and spiritual meditation as well as praise4 ,the modern distinction between psalms and hymns is arbitrary 7see ,,psalms74 ,the former word was used by the ,,lxx4 as a generic designation1 probably because it implied an accompaniment by the psaltery 7said by ,eusebius to have been of very ancient use in the ,east7 or other instruments4 ,the cognate verb psallere has been constantly applied to hymns1 both in the ,eastern and in the ,western ,church2 and the same compositions which they described generically as psalms were also called by the ,,lxx4 odes 7i4e4 songs7 and hymns4 ,the latter word occurs1 e4g4 in ,ps4 lxxii4 #bj 7the hymns of ,david the son of ,jesse71 in ,ps4 lxv4 #a1 and also in the ,greek titles of the #fth1 #edth1 #eeth1 #fgth and #gfth 7this numbering of the psalms being that of the ,english version1 not of the ,,lxx474 ,the #ddth chapter of ,ecclesiasticus1 ,let us now praise famous men1 c41 is entitled in the ,greek ,greek3 patern hymnos1 ,the ,fathers' ,hymn4 ,bede speaks of the whole book of ,psalms as called liber hymnorum1 by the universal consent of ,hebrews1 ,greeks and ,latins4 ,in the ,new ,testament we find our ,lord and ,his apostles singing a hymn 7,greek3 hymnsantes exlthon71 after the institution of the ,lord's ,supper2 ,st ,paul and ,silas doing the same 7,greek3 hymnoun ton theon7 in their prison at ,philippi2 ,st ,james recommending psalm-singing 7,greek3 psallet71 and ,st ,paul psalms and hymns and spiritual songs 7,greek3 psalmois kai hymnois kai dais pneumatikais7 ,st ,paul also1 in the #adth chapter of the first epistle to the ,corinthians1 speaks of singing 7,greek3 psal7 and of every man's psalm 7,greek3 hekastos hymn psalmon echei74 ,in a context which plainly has reference to the assemblies of the ,corinthian ,christians for common worship4 ,all the words thus used were applied by the ,,lxx4 to the ,davidical psalms2 it is therefore possible that these only may be intended1 in the different places to which we have referred4 ,but there are in ,st ,paul's epistles several passages 7,eph4 v4 #ad2 #a ,tim4 iii4 #af2 #a ,tim4 vi4 #ae1 #af2 #b ,tim4 ii4 #aa1 #ab7 which have so much of the form and character of later ,oriental hymnody as to have been supposed by ,michaelis and others to be extracts from original hymns of the ,apostolic age4 ,two of them are apparently introduced as quotations1 though not found elsewhere in the ,scriptures4 ,a third has not only rhythm1 but rhyme4 ,the thanksgiving prayer of the assembled disciples1 recorded in ,acts iv41 is both in substance and in manner poetical2 and in the canticles1 ,magnificat1 ,benedictus1 c41 which manifestly followed the form and style of ,hebrew poetry1 hymns or songs1 proper for liturgical use1 have always been recognized by the church4 #c4 ,eastern ,church ,hymnody4--,the hymn of our ,lord1 the precepts of the apostles1 the angelic song at the nativity1 and ,benedicite omnia opera are referred to in a curious metrical prologue to the hymnary of the ,mozarabic ,breviary as precedents for the practice of the ,western ,church4 ,in this respect1 however1 the ,western ,church followed the ,eastern1 in which hymnody prevailed from the earliest times4 ,therapeutae4 ,philo describes the ,theraputae 7q4v47 of the neighbourhood of ,alexandria as composers of original hymns1 which 7as well as old7 were sung at their great religious festivals--the people listening in silence till they came to the closing strains1 or refrains1 at the end of a hymn or stanza 7the acroteleutia and ephymnia71 in which all1 women as well as men1 heartily joined4 ,these songs1 he says1 were in various metres 7for which he uses a number of technical terms72 some were choral1 some not2 and they were divided into variously constructed strophes or stanzas4 ,eusebius1 who thought that the ,theraputae were communities of ,christians1 says that the ,christian practice of his own day was in exact accordance with this description4 ,antiphonal singing4 ,the practice1 not only of singing hymns1 but of singing them antiphonally1 appears1 from the well-known letter of ,pliny to ,trajan1 to have been established in the ,bithynian churches at the beginning of the #bnd century4 ,they were accustomed stato die ante lucem convenire1 carmenque ,christo1 quasi ,deo1 dicere secum invicem4 ,this agrees well1 in point of time1 with the tradition recorded by the historian ,socrates1 that ,ignatius 7who suffered martyrdom about ,a4,d4 #ajg7 was led by a vision or dream of angels singing hymns in that manner to the ,holy ,trinity to introduce antiphonal singing into the church of ,antioch1 from which it quickly spread to other churches4 ,there seems to be an allusion to choral singing in the epistle of ,ignatius himself to the ,romans1 where he exhorts them1 ,greek3 choros genomenoi 7having formed themselves into a choir71 to sing praise to the ,father in ,christ ,jesus4 ,a statement of ,theodoret has sometimes been supposed to refer the origin of antiphonal singing to a much later date2 but this seems to relate only to the singing of ,old ,testament ,psalms 7,greek3 tn ,dauidikn meldian71 the alternate chanting of which1 by a choir divided into two parts1 was 7according to that statement7 first introduced into the church of ,antioch by two monks famous in the history of their time1 ,flavianus and ,diodorus1 under the emperor ,constantius ,,ii4 #bnd century4 #crd century4 ,other evidence of the use of hymns in the #bnd century is contained in a fragment of ,caius1 preserved by ,eusebius1 which refers to all the psalms and odes written by faithful brethren from the beginning1 as hymning ,christ1 the ,word of ,god1 as ,god4 ,tertullian also1 in his description of the ,agapae1 or love-feasts1 of his day1 says that1 after washing hands and bringing in lights1 each man was invited to come forward and sing to ,god's praise something either taken from the ,scriptures or of his own composition 7ut quisque de ,sacris ,scripturis vel proprio ingenio potest74 ,george ,bull1 bishop of ,st ,david's1 believed one of those primitive compositions to be the hymn appended by ,clement of ,alexandria to his ,paedagogus2 and ,archbishop ,ussher considered the ancient morning and evening hymns1 of which the use was enjoined by the ,apostolical ,constitutions1 and which are also mentioned in the ,tract on ,virginity printed with the works of ,st ,athanasius1 and in ,st ,basil's treatise upon the ,holy ,spirit1 to belong to the same family4 ,clement's hymn1 in a short anapaestic metre1 beginning ,greek3 stomion pln adan 7or1 according to some editions1 ,greek3 basileu hagin1 loge pandamatr--translated by the ,rev4 ,a4 ,chatfield1 ,o ,thou1 the ,king of ,saints1 all-conquering ,word71 is rapid1 spirited and well-adapted for singing4 ,the ,greek ,morning ,hymn 7which1 as divided into verses by ,archbishop ,ussher in his treatise ,de ,symbolis1 has a majestic rhythm1 resembling a choric or dithyrambic strophe7 is the original form of ,gloria in ,excelsis1 still said or sung1 with some variations1 in all branches of the church which have not relinquished the use of liturgies4 ,the ,latin form of this hymn 7of which that in the ,english communion office is an exact translation7 is said1 by ,bede and other ancient writers1 to have been brought into use at ,rome by ,pope ,telesphorus1 as early as the time of the emperor ,hadrian4 ,a third1 the ,vesper or ,lamp-lighting hymn 7,greek3 phs hilaron hagias doxs--translated by ,canon ,bright ,light of ,gladness1 ,beam ,divine71 holds its place to this day in the services of the ,greek rite4 ,in the #crd century ,origen seems to have had in his mind the words of some other hymns or hymn of like character1 when he says 7in his treatise ,against ,celsus73 ,we glorify in hymns ,god and ,his only begotten ,son2 as do also the ,sun1 the ,moon1 the ,stars and all the host of heaven4 ,all these1 in one ,divine chorus1 with the just among men1 glorify in hymns ,god who is over all1 and ,his only begotten ,son4 ,so highly were these compositions esteemed in the ,syrian churches that the council which deposed ,paul of ,samosata from the see of ,antioch in the time of ,aurelian justified that act1 in its synodical letter to the bishops of ,rome and ,alexandria1 on this ground 7among others7 that he had prohibited the use of hymns of that kind1 by uninspired writers1 addressed to ,christ4 ,after the conversion of ,constantine1 the progress of hymnody became closely connected with church controversies4 ,there had been in ,edessa1 at the end of the #bnd or early in the #crd century1 a ,gnostic writer of conspicuous ability1 named ,bardesanes1 who was succeeded1 as the head of his sect or school1 by his son ,harmonius4 ,both father and son wrote hymns1 and set them to agreeable melodies1 which acquired1 and in the #dth century still retained1 much local popularity4 ,ephraem ,syrus1 the first voluminous hymn-writer whose works remain to us1 thinking that the same melodies might be made useful to the faith1 if adapted to more orthodox words1 composed to them a large number of hymns in the ,syriac language1 principally in tetrasyllabic1 pentasyllable and heptasyllabic metres1 divided into strophes of from #d to #ab1 #af and even #bj lines each4 ,when a strophe contained five lines1 the fifth was generally an ephymnium1 detached in sense1 and consisting of a prayer1 invocation1 doxology or the like1 to be sung antiphonally1 either in full chorus or by a separate part of the choir4 ,the ,syriac ,chrestomathy of ,august ,hahn 7,leipzig1 #ahbe71 and the third volume of ,h4 ,a4 ,daniel's ,thesaurus ,hymnologicus 7,leipzig1 #ahda-ahef71 contain specimens of these hymns4 ,some of them have been translated into 7unmetrical7 ,english by the ,rev4 ,henry ,burgess 7,select ,metrical ,hymns of ,ephrem ,syrus1 c41 #ahec74 ,a considerable number of those so translated are on subjects connected with death1 resurrection1 judgment1 c41 and display not only ,christian faith and hope1 but much simplicity and tenderness of natural feeling4 ,theodoret speaks of the spiritual songs of ,ephraem as very sweet and profitable1 and as adding much1 in his 7,theodoret's7 time1 to the brightness of the commemorations of martyrs in the ,syrian ,church4 ,the ,greek hymnody contemporary with ,ephraem followed1 with some licence1 classical models4 ,one of its favourite metres was the ,anacreontic2 but it also made use of the short anapaestic1 ,ionic1 iambic and other lyrical measures1 as well as the hexameter and pentameter4 ,its principal authors were ,methodius1 bishop of ,olympus1 who died about ,a4,d4 #caa1 ,synesius1 who became bishop of ,ptolemais in ,cyrenaica in #daj1 and ,gregory ,nazianzen1 for a short time 7#chj-cha7 patriarch of ,constantinople4 ,the merits of these writers have been perhaps too much depreciated by the admirers of the later ,greek ,melodists4 ,they have found an able ,english translator in the ,rev4 ,allen ,chatfield 7,songs and ,hymns of ,earliest ,greek ,christian ,poets1 ,london1 #ahgf74 ,among the most striking of their works are ,greek3 mneo ,christe 7,lord ,jesus1 think of me71 by ,synesius2 ,greek3 se ton aphthiton monarchn 7,o ,thou1 the ,one ,supreme7 and ,greek3 ti soi theleis genesthai 7,o soul of mine1 repining71 by ,gregory2 also ,greek3 anthen parthenoi 7,the ,bridegroom cometh71 by ,methodius4 ,there continued to be ,greek metrical hymn-writers1 in a similar style1 till a much later date4 ,sophronius1 patriarch of ,jerusalem in the #gth century1 wrote seven ,anacreontic hymns2 and ,st ,john ,damascene1 one of the most copious of the second school of ,melodists1 was also the author of some long compositions in trimeter iambics4 ,period of ,arian controversy4 ,an important development of hymnody at ,constantinople arose out of the ,arian controversy4 ,early in the #dth century ,athanasius had rebuked1 not only the doctrine of ,arius1 but the light character of certain hymns by which he endeavoured to make that doctrine popular4 ,when1 towards the close of that century 7#cih71 ,st ,john ,chrysostom was raised to the metropolitan see1 the ,arians1 who were still numerous at ,constantinople1 had no places of worship within the walls2 but they were in the habit of coming into the city at sunset on ,saturdays1 ,sundays and the greater festivals1 and congregating in the porticoes and other places of public resort1 where they sung1 all night through1 antiphonal songs1 with acroteleutia 7closing strains1 or refrains71 expressive of ,arian doctrine1 often accompanied by taunts and insults to the orthodox4 ,chrysostom was apprehensive that this music might draw some of the simpler church people to the ,arian side2 he therefore organized1 in opposition to it1 under the patronage and at the cost of ,eudoxia1 the empress of ,arcadius 7then his friend71 a system of nightly processional hymn-singing1 with silver crosses1 wax-lights and other circumstances of ceremonial pomp4 ,riots followed1 with bloodshed on both sides1 and with some personal injury to the empress's chief eunuch1 who seems to have officiated as conductor or director of the church musicians4 ,this led to the suppression1 by an imperial edict1 of all public ,arian singing2 while in the church the practice of nocturnal hymn-singing on certain solemn occasions1 thus first introduced1 remained an established institution4 ,greek system of hymnody4 ,it is not improbable that some rudiments of the peculiar system of hymnody which now prevails throughout the ,greek communion1 and whose affinities are rather to the ,hebrew and ,syriac than to the classical forms1 may have existed in the church of ,constantinople1 even at that time4 ,anatolius1 patriarch of ,constantinople in the middle of the #eth century1 was the precursor of that system2 but the reputation of being its proper founder belongs to ,romanos1 of whom little more is known than that he wrote hymns still extant1 and lived towards the end of that century4 ,the importance of that system in the services of the ,greek church may be understood from the fact that ,dr ,j4 ,m4 ,neale computed four-fifths of the whole space 7about #ejjj pages7 contained in the different service-books of that church to be occupied by hymnody1 all in a language or dialect which has ceased to be anywhere spoken4 ,the system has a peculiar technical terminology1 in which the words troparion1 ode1 canon and hirmus 7,greek3 eirmos7 chiefly require explanation4 ,the troparion is the unit of the system1 being a strophe or stanza1 seen1 when analysed1 to be divisible into verses or clauses1 with regulated caesuras1 but printed in the books as a single prose sentence1 without marking any divisions4 ,the following 7turned into ,english1 from a canon by ,john ,mauropus7 may be taken as an example3 ,the never-sleeping ,guardian1 the patron of my soul1 the guide of my life1 allotted me by ,god1 ,i hymn thee1 ,divine ,angel of ,almighty ,god4 ,dr ,neale and most other writers regard all these troparia as rhythmical or modulated prose4 ,cardinal ,j4 ,b4 ,pitra1 on the other hand1 who in #ahfg and #ahgf published two learned works on this subject1 maintains that they are really metrical1 and governed by definite rules of prosody1 of which he lays down sixteen4 ,according to him1 each troparion contains from three to thirty-three verses2 each verse varies from two to thirteen syllables1 often in a continuous series1 uniform1 alternate or reciprocal1 the metre being always syllabic1 and depending1 not on the quantity of vowels or the position of consonants1 but on an harmonic series of accents4 ,in various parts of the services solitary troparia are sung1 under various names1 contacion1 oecos1 cathisma1 c41 which mark distinctions either in their character or in their use4 ,an ode is a song or hymn compounded of several similar troparia1--usually three1 four or five4 ,to these is always prefixed a typical or standard troparion1 called the hirmus1 by which the syllabic measure1 the periodic series of accents1 and in fact the whole structure and rhythm of the stanzas which follow it are regulated4 ,each succeeding troparion in the same ode contains the same number of verses1 and of syllables in each verse1 and similar accents on the same or equivalent syllables4 ,the hirmus may either form the first stanza of the ode itself1 or 7as is more frequently the case7 may be taken from some other piece2 and1 when so taken1 it is often indicated by initial words only1 without being printed at length4 ,it is generally printed within commas1 after the proper rubric of the ode4 ,a hymn in irregular stichera or stanzas1 without a hirmus1 is called idiomelon4 ,a system of three or four odes is triodion or tetraodion4 ,a canon is a system of eight 7theoretically nine7 connected odes1 the second being always suppressed4 ,various pauses1 relieved by the interposition of other short chants or readings1 occur during the singing of a whole canon4 ,the final troparion in each ode of the series is not unfrequently detached in sense 7like the ephymnia of ,ephraem ,syrus71 particularly when it is in the 7very common7 form of a theotokion1 or ascription of praise to the mother of our ,lord1 and when it is a recurring refrain or burden4 ,there were two principal periods of ,greek hymnography constructed on these principles--the first that of ,romanos and his followers1 extending over the #fth and #gth centuries1 the second that of the schools which arose during the ,iconoclastic controversy in the #hth century1 and which continued for some centuries afterwards1 until the art itself died out4 ,school of ,romanos4 ,the works of the writers of the former period were collected in ,tropologia1 or church hymn-books1 which were held in high esteem till the #ajth century1 when they ceased to be regarded as church-books1 and so fell into neglect4 ,they are now preserved only in a very small number of manuscripts4 ,from three of these1 belonging to public libraries at ,moscow1 ,turin and ,rome1 ,cardinal ,pitra has printed1 in his ,analecta1 a number of interesting examples1 the existence of which appears to have been unknown to ,dr ,neale1 and which1 in the cardinal's estimation1 are in many respects superior to the canons1 c41 of the modern ,greek service-books1 from which all ,neale's translations 7except some from ,anatolius7 are taken4 ,cardinal ,pitra's selections include twenty-nine works by ,romanos1 and some by ,sergius1 and nine other known1 as well as some unknown1 authors4 ,he describes them as having generally a more dramatic character than the melodies of the later period1 and a much more animated style2 and he supposes that they may have been originally sung with dramatic accompaniments1 by way of substitution for the theatrical performances of ,pagan times4 ,as an instance of their peculiar character1 he mentions a ,christmas or ,epiphany hymn by ,romanos1 in twenty-five long strophes1 in which there is1 first1 an account of the ,nativity and its accompanying wonders1 and then a dialogue between the wise men1 the ,virgin mother and ,joseph4 ,the magi arrive1 are admitted1 describe the moral and religious condition of ,persia and the ,east1 and the cause and adventures of their journey1 and then offer their gifts4 ,the ,virgin intercedes for them with her ,son1 instructs them in some parts of ,jewish history1 and ends with a prayer for the salvation of the world4 ,melodists4 ,the controversies and persecutions of the #hth and succeeding centuries turned the thoughts of the melodists of the great monasteries of the ,studium at ,constantinople and ,st ,saba in ,palestine and their followers1 and those of the adherents of the ,greek rite in ,sicily and ,south ,italy 7who suffered much from the ,saracens and the ,normans71 into a less picturesque but more strictly theological course2 and the influence of those controversies1 in which the final success of the cause of ,icons was largely due to the hymns1 as well as to the courage and sufferings1 of these confessors1 was probably the cause of their supplanting1 as they did1 the works of the older school4 ,cardinal ,pitra gives them the praise of having discovered a graver and more solemn style of chant1 and of having done much to fix the dogmatic theology of their church upon its present lines of near approach to the ,roman4 ,among the melodists of this latter ,greek school there were many saints of the ,greek church1 several patriarchs and two emperors--,leo the ,philosopher1 and ,constantine ,porphyrogenitus1 his son4 ,their greatest poets were ,theodore and ,joseph of the ,studium1 and ,cosmas and ,john 7called ,damascene7 of ,st ,saba4 ,neale translated into ,english verse several selected portions1 or centoes1 from the works of these and others1 together with four selections from earlier works by ,anatolius4 ,some of his translations--particularly ,the day is past and over1 from ,anatolius1 and ,christian1 dost thou see them1 from ,andrew of ,crete--have been adopted into hymn-books used in many ,english churches2 and the hymn ,art thou weary1 which is rather founded upon than translated from one by ,stephen the ,sabaite1 has obtained still more general popularity4 #d4 ,western ,church ,hymnody4--,it was not till the #dth century that ,greek hymnody was imitated in the ,west1 where its introduction was due to two great lights of the ,latin ,church--,st ,hilary of ,poitiers and ,st ,ambrose of ,milan4 ,hilary was banished from his see of ,poitiers in #cef1 and was absent from it for about four years1 which he spent in ,asia ,minor1 taking part during that time in one of the councils of the ,eastern ,church4 ,he thus had full opportunity of becoming acquainted with the ,greek church music of that day2 and he wrote 7as ,st ,jerome1 who was thirty years old when ,hilary died1 and who was well acquainted with his acts and writings1 and spent some time in or near his diocese1 informs us7 a book of hymns1 to one of which ,jerome particularly refers1 in the preface to the second book of his own commentary on the epistle to the ,galatians4 ,isidore1 archbishop of ,seville1 who presided over the fourth council of ,toledo1 in his book on the offices of the church1 speaks of ,hilary as the first ,latin hymn-writer2 that council itself1 in its #acth canon1 and the prologue to the ,mozarabic hymnary 7which is little more than a versification of the canon71 associate his name1 in this respect1 with that of ,ambrose4 ,a tradition1 ancient and widely spread1 ascribed to him the authorship of the remarkable ,hymnum dicat turba fratrum1 hymnum cantus personet 7,band of brethren1 raise the hymn1 let your song the hymn resound71 which is a succinct narrative1 in hymnal form1 of the whole gospel history2 and is perhaps the earliest example of a strictly didactic hymn4 ,both ,bede and ,hincmar much admired this composition1 though the former does not mention1 in connexion with it1 the name of ,hilary4 ,the private use of hymns of such a character by ,christians in the ,west may probably have preceded their ecclesiastical use2 for ,jerome says that in his day those who went into the fields might hear the ploughman at his hallelujahs1 the mower at his hymns1 and the vine-dresser singing ,david's psalms4 ,besides this1 seven shorter metrical hymns attributed to ,hilary are still extant4 ,ambrose4 ,of the part taken by ,ambrose1 not long after ,hilary's death1 in bringing the use of hymns into the church of ,milan1 we have a contemporary account from his convert1 ,st ,augustine4 ,justina1 mother of the emperor ,valentinian1 favoured the ,arians1 and desired to remove ,ambrose from his see4 ,the devout people1 of whom ,augustine's mother1 ,monica1 was one1 combined to protect him1 and kept guard in the church4 ,then1 says ,augustine1 it was first appointed that1 after the manner of the ,eastern churches1 hymns and psalms should be sung1 lest the people should grow weary and faint through sorrow2 which custom has ever since been retained1 and has been followed by almost all congregations in other parts of the world4 ,he describes himself as moved to tears by the sweetness of these hymns and canticles3--,the voices flowed into my ears2 the truth distilled into my heart2 ,i overflowed with devout affections1 and was happy4 ,to this time1 according to an uncertain but not improbable tradition which ascribed the composition of the ,te ,deum to ,ambrose1 and connected it with the conversion of ,augustine1 is to be referred the commencement of the use in the church of that sublime unmetrical hymn4 ,it is not1 however1 to be assumed that the hymnody thus introduced by ,ambrose was from the first used according to the precise order and method of the later ,western ritual4 ,to bring it into 7substantially7 that order and method appears to have been the work of ,st ,benedict4 ,walafrid ,strabo1 the earliest ecclesiastical writer on this subject 7who lived at the beginning of the #ith century71 says that ,benedict1 on the constitution of the religious order known by his name 7about #ecj71 appointed the ,ambrosian hymns to be regularly sung in his offices for the canonical hours4 ,hence probably originated the practice of the ,italian churches1 and of others which followed their example1 to sing certain hymns 7,ambrosian1 or by the early successors of the ,ambrosian school7 daily throughout the week1 at ,vespers1 ,lauds and ,nocturns1 and on some days at ,compline also--varying them with the different ecclesiastical seasons and festivals1 commemorations of saints and martyrs and other special offices4 ,different dioceses and religious houses had their own peculiarities of ritual1 including such hymns as were approved by their several bishops or ecclesiastical superiors1 varying in detail1 but all following the same general method4 ,the national rituals1 which were first reduced into a form substantially like that which has since prevailed1 were probably those of ,lombardy and of ,spain1 now known as the ,ambrosian and the ,mozarabic4 ,the age and origin of the ,spanish ritual are uncertain1 but it is mentioned in the #gth century by ,isidore1 bishop of ,seville4 ,it contained a copious hymnary1 the original form of which may be regarded as canonically approved by the fourth council of ,toledo 7#fcc74 ,by the #acth canon of that council1 an opinion 7which even then found advocates7 against the use in churches of any hymns not taken from the ,scriptures--apparently the same opinion which had been held by ,paul of ,samosata--was censured2 and it was ordered that such hymns should be used in the ,spanish as well as in the ,gallican churches1 the penalty of excommunication being denounced against all who might presume to reject them4 ,the hymns of which the use was thus established and authorized were those which entered into the daily and other offices of the church1 afterwards collected in the ,breviaries2 in which the hymns proper for the week1 and for the season1 continued for many centuries1 with very few exceptions1 to be derived from the earliest epoch of ,latin ,church poetry--reckoning that epoch as extending from ,hilary and ,ambrose to the end of the pontificate of ,gregory the ,great4 ,the ,ambrosian music1 to which those hymns were generally sung down to the time of ,gregory1 was more popular and congregational than the ,gregorian1 which then came into use1 and afterwards prevailed4 ,in the service of the mass it was not the general practice1 before the invention of sequences in the #ith century1 to sing any hymns1 except some from the ,scriptures esteemed canonical1 such as the ,song of the ,three ,children 7,benedicite omnia opera74 ,but to this rule there were1 according to ,walafrid ,strabo1 some occasional exceptions2 particularly in the case of ,paulinus1 patriarch of ,aquileia under ,charlemagne1 himself a hymn-writer1 who frequently used hymns1 composed by himself or others1 in the eucharistic office1 especially in private masses4 ,some of the hymns called ,ambrosian 7nearly #ajj in number7 are beyond all question by ,ambrose himself1 and the rest probably belong to his time or to the following century4 ,four1 those beginning ,aeterne rerum conditor 7,dread ,framer of the earth and sky71 ,deus ,creator omnium 7,maker of all things1 glorious ,god71 ,veni ,redemptor ,gentium 7,redeemer of the nations1 come7 and ,jam surgit hora tertia 7,christ at this hour was crucified71 are quoted as works of ,ambrose by ,augustine4 ,these1 and others by the hand of the same master1 have the qualities most valuable in hymns intended for congregational use4 ,they are short and complete in themselves2 easy1 and at the same time elevated in their expression and rhythm2 terse and masculine in thought and language2 and 7though sometimes criticized as deficient in theological precision7 simple1 pure and not technical in their rendering of the great facts and doctrines of ,christianity1 which they present in an objective and not a subjective manner4 ,they have exercised a powerful influence1 direct or indirect1 upon many of the best works of the same kind in all succeeding generations4 ,with the ,ambrosian hymns are properly classed those of ,hilary1 and the contemporary works of ,pope ,damasus ,i4 7who wrote two hymns in commemoration of saints71 and of ,prudentius1 from whose ,cathemerina 7,daily ,devotions7 and ,peristephana 7,crown-songs for ,martyrs71 all poems of considerable1 some of great length--about twenty-eight hymns1 found in various ,breviaries1 were derived4 ,prudentius was a layman1 a native of ,saragossa1 and it was in the ,spanish ritual that his hymns were most largely used4 ,in the ,mozarabic ,breviary almost the whole of one of his finest poems 7from which most churches took one part only1 beginning ,corde natus ex parentis7 was appointed to be sung between ,easter and ,ascension-,day1 being divided into eight or nine hymns2 and on some of the commemorations of ,spanish saints long poems from his ,peristephana were recited or sung at large4 ,he is entitled to a high rank among ,christian poets1 many of the hymns taken from his works being full of fervour and sweetness1 and by no means deficient in dignity or strength4 #eth and #fth centuries4 ,these writers were followed in the #eth and early in the #fth century by the priest ,sedulius1 whose reputation perhaps exceeded his merit2 ,elpis1 a noble ,roman lady 7considered1 by an erroneous tradition1 to have been the wife of the philosophic statesman ,boetius72 ,pope ,gelasius ,i42 and ,ennodius1 bishop of ,pavia4 ,sedulius and ,elpis wrote very little from which hymns could be extracted2 but the small number taken from their compositions obtained wide popularity1 and have since held their ground4 ,gelasius was of no great account as a hymn-writer2 and the works of ,ennodius appear to have been known only in ,italy and ,spain4 ,the latter part of the #fth century produced ,pope ,gregory the ,great and ,venantius ,fortunatus1 an ,italian poet1 the friend of ,gregory1 and the favourite of ,radegunda1 queen of the ,franks1 who died 7#fji7 bishop of ,poitiers4 ,eleven hymns of ,gregory1 and twelve or thirteen 7mostly taken from longer poems7 by ,fortunatus1 came into general use in the ,italian1 ,gallican and ,british churches4 ,those of ,gregory are in a style hardly distinguishable from the ,ambrosian2 those of ,fortunatus are graceful1 and sometimes vigorous4 ,he does not1 however1 deserve the praise given to him by ,dr ,neale1 of having struck out a new path in ,latin hymnody4 ,on the contrary1 he may more justly be described as a disciple of the school of ,prudentius1 and as having affected the classical style1 at least as much as any of his predecessors4 ,the poets of this primitive epoch1 which closed with the #fth century1 wrote in the old classical metres1 and made use of a considerable variety of them--anapaestic1 anacreontic1 hendecasyllabic1 asclepiad1 hexameters and pentameters and others4 ,gregory and some of the ,ambrosian authors occasionally wrote in sapphics2 but the most frequent measure was the iambic dimeter1 and1 next to that1 the trochaic4 ,the full alcaic stanza does not appear to have been used for church purposes before the #afth century1 though some of its elements were4 ,in the greater number of these works1 a general intention to conform to the rules of ,roman prosody is manifest2 but even those writers 7like ,prudentius7 in whom that conformity was most decided allowed themselves much liberty of deviation from it4 ,other works1 including some of the very earliest1 and some of conspicuous merit1 were of the kind described by ,bede as not metrical but rhythmical--i4e4 7as he explains the term rhythm71 modulated to the ear in imitation of different metres4 ,it would be more correct to call them metrical--7e4g4 still trochaic or iambic1 c41 but1 according to new laws of syllabic quantity1 depending entirely on accent1 and not on the power of vowels or the position of consonants7--laws by which the future prosody of all modern ,european nations was to be governed4 ,there are also1 in the hymns of the primitive period 7even in those of ,ambrose71 anticipations--irregular indeed and inconstant1 but certainly not accidental--of another great innovation1 destined to receive important developments1 that of assonance or rhyme1 in the final letters or syllables of verses4 ,archbishop ,trench1 in the introduction to his ,sacred ,latin ,poetry1 has traced the whole course of the transition from the ancient to the modern forms of versification1 ascribing it to natural and necessary causes1 which made such changes needful for the due development of the new forms of spiritual and intellectual life1 consequent upon the conversion of the ,latin-speaking nations to ,christianity4 #fth century downwards4 ,from the #fth century downwards we see this transformation making continual progress1 each nation of ,western ,christendom adding1 from time to time1 to the earlier hymns in its service-books others of more recent and frequently of local origin4 ,for these additions1 the commemorations of saints1 c41 as to which the devotion of one place often differed from that of another1 offered especial opportunities4 ,this process1 while it promoted the development of a medieval as distinct from the primitive style1 led also to much deterioration in the quality of hymns1 of which1 perhaps1 some of the strongest examples may be found in a volume published in #ahfe by the ,irish ,archaeological ,society from a manuscript in the library of ,trinity ,college1 ,dublin4 ,it contains a number of hymns by ,irish saints of the #fth1 #gth and #hth centuries--in several instances fully rhymed1 and in one mixing ,erse and ,latin barbarously together1 as was not uncommon1 at a much later date1 in semi-vernacular hymns of other countries4 ,the ,mozarabic ,breviary1 and the collection of hymns used in the ,anglo-,saxon churches1 published in #ahea by the ,surtees ,society 7chiefly from a ,benedictine ,,ms4 ,in the college library of ,durham1 supplemented by other ,,mss4 in the ,british ,museum71 supply many further illustrations of the same decline of taste3--such ,sapphics1 e4g41 as the ,festum insigne prodiit coruscum of ,isidore1 and the ,o veneranda ,trinitas laudanda of the ,anglo-,saxon books4 ,the early medieval period1 however1 from the time of ,gregory the ,great to that of ,hildebrand1 was far from deficient in the production of good hymns1 wherever learning flourished4 ,bede in ,england1 and ,paul the ,deacon--the author of a fairly classical sapphic ode on ,st ,john the ,baptist--in ,italy1 were successful followers of the ,ambrosian and ,gregorian styles4 ,eleven metrical hymns are attributed to ,bede by ,cassander2 and there are also in one of ,bede's works 7,collectanea et flores7 two rhythmical hymns of considerable length on the ,day of ,judgment1 with the refrains ,in tremendo die and ,attende homo1 both irregularly rhymed1 and1 in parts1 not unworthy of comparison with the ,dies ,irae4 ,paulinus1 patriarch of ,aquileia1 contemporary with ,paul1 wrote rhythmical trimeter iambics in a manner peculiar to himself4 ,theodulph1 bishop of ,orleans 7#gic-hce71 author of the famous processional hymn for ,palm ,sunday in hexameters and pentameters1 ,gloria1 laus1 et honor tibi sit1 ,rex ,christe ,redemptor 7,glory and honour and laud be to ,thee1 ,king ,christ the ,redeemer71 and ,hrabanus ,maurus1 archbishop of ,mainz1 the pupil of ,alcuin1 and the most learned theologian of his day1 enriched the church with some excellent works4 ,among the anonymous hymns of the same period there are three of great beauty1 of which the influence may be traced in most1 if not all1 of the ,new ,jerusalem hymns of later generations1 including those of ,germany and ,great ,britain3--,urbs beata ,hierusalem 7,blessed city1 heavenly ,salem72 ,alleluia piis edite laudibus 7,alleluias sound ye in strains of holy praise--called1 from its burden1 ,alleluia perenne72 and ,alleluia dulce carmen 7,alleluia1 song of sweetness71 which1 being found in ,anglo-,saxon hymnaries certainly older than the ,conquest1 cannot be of the late date assigned to it1 in his ,mediaeval ,hymns and ,sequences1 by ,neale4 ,these were followed by the ,chorus novae ,hierusalem 7,ye ,choirs of ,new ,jerusalem7 of ,fulbert1 bishop of ,chartres4 ,this group of hymns is remarkable for an attractive union of melody1 imagination1 poetical colouring and faith4 ,it represents1 perhaps1 the best and highest type of the middle school1 between the severe ,ambrosian simplicity and the florid luxuriance of later times4 ,veni ,creator4 ,notker4 ,another celebrated hymn1 which belongs to the first medieval period1 is the ,veni ,creator ,spiritus 7,come1 ,holy ,ghost1 our souls inspire74 ,the earliest recorded occasion of its use is that of a translation 7#hih7 of the relics of ,st ,marcellus1 mentioned in the ,annals of the ,benedictine order4 ,it has since been constantly sung throughout ,western ,christendom 7as versions of it still are in the ,church of ,england71 as part of the appointed offices for the coronation of kings1 the consecration and ordination of bishops and priests1 the assembling of synods and other great ecclesiastical solemnities4 ,it has been attributed--probably in consequence of certain corruptions in the text of ,ekkehard's ,life of ,notker 7a work of the #acth century7--to ,charlemagne4 ,ekkehard wrote in the ,benedictine monastery of ,st ,gall1 to which ,notker belonged1 with full access to its records2 and an ignorant interpolator1 regardless of chronology1 added1 at some later date1 the word ,great to the name of the emperor ,charles1 wherever it was mentioned in that work4 ,the biographer relates that ,notker--a man of a gentle1 contemplative nature1 observant of all around him1 and accustomed to find spiritual and poetical suggestions in common sights and sounds--was moved by the sound of a mill-wheel to compose his sequence on the ,holy ,spirit1 ,sancti ,spiritus adsit nobis gratia 7,present with us ever be the ,holy ,spirit's grace72 and that1 when finished1 he sent it as a present to the emperor ,charles1 who in return sent him back1 by the same messenger1 the hymn ,veni ,creator1 which 7says ,ekkehard7 the same ,spirit had inspired him to write 7,sibi idem ,spiritus inspiraverat74 ,if this story is to be credited--and1 from its circumstantial and almost dramatic character1 it has an air of truth--the author of ,veni ,creator was not ,charlemagne1 but his grandson the emperor ,charles the ,bald4 ,notker himself long survived that emperor1 and died in #iab4 ,sequences4 ,the invention of sequences by ,notker may be regarded as the beginning of the later medieval epoch of ,latin hymnody4 ,in the eucharistic service1 in which 7as has been stated7 hymns were not generally used1 it had been the practice1 except at certain seasons1 to sing laud1 or ,alleluia1 between the epistle and the gospel1 and to fill up what would otherwise have been a long pause1 by extending the cadence upon the two final vowels of the ,alleluia into a protracted strain of music4 ,it occurred to ,notker that1 while preserving the spirit of that part of the service1 the monotony of the interval might be relieved by introducing at that point a chant of praise specially composed for the purpose4 ,with that view he produced the peculiar species of rhythmical composition which obtained the name of sequentia 7probably from following after the close of the ,alleluia71 and also that of prosa1 because its structure was originally irregular and unmetrical1 resembling in this respect the ,greek troparia1 and the ,te ,deum1 ,benedicite and canticles4 ,that it was in some measure suggested by the forms of the later ,greek hymnody seems probable1 both from the intercourse 7at that time frequent7 between the ,eastern and ,western churches1 and from the application by ,ekkehard1 in his biography and elsewhere 7e4g4 in ,lyndwood's ,provinciale71 of some technical terms1 borrowed from the ,greek terminology1 to works of ,notker and his school and to books containing them4 ,dr ,neale1 in a learned dissertation prefixed to his collection of sequences from medieval ,missals1 and enlarged in a ,latin letter to ,h4 ,a4 ,daniel 7printed in the fifth volume of ,daniel's ,thesaurus hymnologicus71 investigated the laws of caesura and modulation which are discoverable in these works4 ,those first brought into use were sent by their author to ,pope ,nicholas ,i41 who authorized their use1 and that of others composed after the same model by other brethren of ,st ,gall1 in all churches of the ,west4 ,although the sequences of ,notker and his school1 which then rapidly passed into most ,german1 ,french and ,british ,missals1 were not metrical1 the art of assonance was much practised in them4 ,many of those in the ,sarum and ,french ,missals have every verse1 and even every clause or division of a verse1 ending with the same vowel a--perhaps with some reference to the terminal letter of ,alleluia4 ,artifices such as these naturally led the way to the adaptation of the same kind of composition to regular metre and fully developed rhyme4 ,neale's full and large collection1 and the second volume of ,daniel's ,thesaurus1 contain numerous examples1 both of the proses1 properly so called1 of the ,notkerian type1 and of those of the later school1 which 7from the religious house to which its chief writer belonged7 has been called ,victorine4 ,most ,missals appear to have contained some of both kinds4 ,in the majority of those from which ,neale's specimens are taken1 the metrical kind largely prevailed2 but in some 7e4g4 those of ,sarum and ,lige7 the greater number were ,notkerian4 ,of the sequence on the ,holy ,ghost1 sent by ,notker 7according to ,ekkehard7 to ,charles the ,bald1 ,neale says that it was in use all over ,europe1 even in those countries1 like ,italy and ,spain1 which usually rejected sequences2 and that1 in the ,missal of ,palencia1 the priest was ordered to hold a white dove in his hands1 while intoning the first syllables1 and then to let it go4 ,another of the most remarkable of ,notker's sequences1 beginning ,media in vita 7,in the midst of life we are in death71 is said to have been suggested to him while observing some workmen engaged in the construction of a bridge over a torrent near his monastery4 ,catherine ,winkworth 7,christian ,singers of ,germany1 #ahfi7 states that this was long used as a battle-song1 until the custom was forbidden1 on account of its being supposed to exercise a magical influence4 ,a translation of it 7,mitten wir im ,leben sind7 is one of ,luther's funeral hymns2 and all but the opening sentence of that part of the burial service of the ,church of ,england which is directed to be said or sung at the grave1 while the corpse is made ready to be laid into the earth1 is taken from it4 ,the ,golden ,sequence1 ,veni1 sancte ,spiritus 7,holy ,spirit1 ,lord of ,light71 is an early example of the transition of sequences from a simply rhythmical to a metrical form4 ,archbishop ,trench1 who esteemed it the loveliest of all the hymns in the whole circle of ,latin sacred poetry1 inclined to give credit to a tradition which ascribes its authorship to ,robert ,,ii41 king of ,france1 son of ,hugh ,capet4 ,others have assigned to it a later date--some attributing it to ,pope ,innocent ,,iii41 and some to ,stephen ,langton1 archbishop of ,canterbury4 ,many translations1 in ,german1 ,english and other languages1 attest its merit4 ,berengarius of ,tours1 ,st ,bernard of ,clairvaux and ,abelard1 in the #aath century and early in the #abth1 followed in the same track2 and the art of the ,victorine school was carried to its greatest perfection by ,adam of ,st ,victor 7who died between #aagc and #aaid7--the most fertile1 and 7in the concurrent judgment of ,archbishop ,trench and ,neale7 the greatest of the ,latin hymnographers of the ,middle ,ages4 ,the archbishop's selection contains many excellent specimens of his works4 ,dies ,irae4 ,stabat ,mater4 ,aquinas4 ,but the two most widely celebrated of all this class of compositions--works which have exercised the talents of the greatest musical composers1 and of innumerable translators in almost all languages--are the ,dies ,irae 7,that day of wrath1 that dreadful day71 by ,thomas of ,celano1 the companion and biographer of ,st ,francis of ,assisi1 and the ,stabat ,mater dolorosa 7,by the cross sad vigil keeping7 of ,jacopone1 or ,jacobus de ,benedictis1 a ,franciscan humorist and reformer1 who was persecuted by ,pope ,boniface ,,viii4 for his satires on the prelacy of the time1 and died in #acjf4 ,besides these1 the #acth century produced the famous sequence ,lauda ,sion salvatorem 7,sion1 lift thy voice and sing71 and the four other well-known sacramental hymns of ,st ,thomas ,aquinas1 viz4 ,pange lingua gloriosi corporis mysterium 7,sing1 my tongue1 the ,saviour's glory71 ,verbum supernum prodiens 7,the ,word1 descending from above--not to be confounded with the ,ambrosian hymn from which it borrowed the first line71 ,sacris solemniis juncta sint gaudia 7,let us with hearts renewed our grateful homage pay71 and ,adoro ,te devote1 latens ,deitas 7,o ,godhead hid1 devoutly ,i adore ,thee7--a group of remarkable compositions1 written by him for the then new festival of ,corpus ,christi1 of which he induced ,pope ,urban ,,iv4 7#abfa-abfe7 to decree the observance4 ,in these 7of which all but ,adoro ,te devote passed rapidly into breviaries and missals7 the doctrine of transubstantiation is set forth with a wonderful degree of scholastic precision2 and they exercised1 probably1 a not unimportant influence upon the general reception of that dogma4 ,they are undoubtedly works of genius1 powerful in thought1 feeling and expression4 ,medieval hymns4 ,these and other medieval hymn-writers of the #abth and #acth centuries may be described1 generally1 as poet-schoolmen4 ,their tone is contemplative1 didactic1 theological2 they are especially fertile and ingenious in the field of mystical interpretation4 ,two great monasteries in the ,east had1 in the #hth and #ith centuries1 been the principal centres of ,greek hymnology2 and1 in the ,west1 three monasteries--,st ,gall1 near ,constance 7which was long the especial seat of ,german religious literature71 ,cluny in ,burgundy and ,st ,victor1 near ,paris--obtained a similar distinction4 ,st ,gall produced1 besides ,notker1 several distinguished sequence writers1 probably his pupils--,hartmann1 ,hermann and ,gottschalk--to the last of whom ,neale ascribes the ,alleluiatic ,sequence 7,cantemus cuncti melodum nunc ,alleluia71 well known in ,england through his translation1 ,the strain upraise of joy and praise4 ,the chief poets of ,cluny were two of its abbots1 ,odo and ,peter the ,venerable 7#aabb-aaef71 and one of ,peter's monks1 ,bernard of ,morlaix1 who wrote the remarkable poem on ,contempt of the ,world in about #cjjj long rolling leonine-dactylic verses1 from parts of which ,neale's popular hymns1 ,jerusalem the golden1 c41 are taken4 ,the abbey of ,st ,victor1 besides ,adam and his follower ,pistor1 was destined afterwards to produce the most popular church poet of the #agth century4 ,bernard of ,clairvaux4 ,there were other distinguished ,latin hymn-writers of the later medieval period besides those already mentioned4 ,the name of ,st ,bernard of ,clairvaux cannot be passed over with the mere mention of the fact that he was the author of some metrical sequences4 ,he was1 in truth1 the father1 in ,latin hymnody1 of that warm and passionate form of devotion which some may consider to apply too freely to ,divine ,objects the language of human affection1 but which has1 nevertheless1 been popular with many devout persons1 in ,protestant as well as ,roman ,catholic churches4 ,f4 von ,spee1 ,angelus ,silesius1 ,madame ,guyon1 ,bishop ,ken1 ,count ,zinzendorf and ,frederick ,william ,faber may be regarded as disciples in this school4 ,many hymns1 in various languages1 have been founded upon ,st ,bernard's ,jesu dulcis memoria 7,jesu1 the very thought of ,thee71 ,jesu dulcedo cordium 7,jesu1 ,thou joy of loving hearts7 and ,jesu ,rex admirabilis 7,o ,jesu1 ,king most wonderful7--three portions of one poem1 nearly #bjj lines long4 ,pietro ,damiani1 the friend of ,pope ,gregory ,,vii1 ,marbode1 bishop of ,rennes1 in the #aath1 ,hildebert1 archbishop of ,tours1 in the #abth1 and ,st ,bonaventura in the #acth centuries1 are other eminent men who added poetical fame as hymnographers to high public distinction4 ,before the time of the ,reformation1 the multiplication of sequences 7often as unedifying in matter as unpoetical in style7 had done much to degrade the common conception of hymnody4 ,in some parts of ,france1 ,portugal1 ,sardinia and ,bohemia1 their use in the vernacular language had been allowed4 ,in ,germany also there were vernacular sequences as early as the #abth century1 specimens of which may be seen in the third chapter of ,c4 ,winkworth's ,christian ,singers of ,germany4 ,scoffing parodies upon sequences are said to have been among the means used in ,scotland to discredit the old church services4 ,after the #aeth century they were discouraged at ,rome4 ,they retained for a time some of their old popularity among ,german ,protestants1 and were only gradually relinquished in ,france4 ,a new prose1 in honour of ,st ,maxentia1 is among the compositions of ,jean ,baptiste ,santeul2 and ,dr ,daniel's second volume closes with one written in #ahee upon the dogma of the ,immaculate ,conception4 ,roman revision of hymns4 ,the taste of the ,renaissance was offended by all deviations from classical prosody and ,latinity4 ,pope ,leo ,x4 directed the whole body of the hymns in use at ,rome to be reformed2 and the ,hymni novi ecclesiastici juxta veram metri et ,latinitatis normam1 prepared by ,zacharie ,ferreri 7#adgi-aecj71 a ,benedictine of ,monte ,cassino1 afterwards a ,carthusian and bishop of ,guardia1 to whom ,leo had committed that task1 appeared at ,rome in #aebe1 with the sanction of a later pope1 ,clement ,,vii4 ,the next step was to revise the whole ,roman ,breviary4 ,that undertaking1 after passing through several stages under different popes 7particularly ,pius ,v4 and ,clement ,,viii471 was at last brought to a conclusion by ,urban ,,viii41 in #afca4 ,from this revised ,breviary a large number of medieval hymns1 both of the earlier and the later periods1 were excluded2 and in their places many new hymns1 including some by ,pope ,urban himself1 and some by ,cardinal ,bellarmine and another cardinal 7,silvius ,antonianus7 were introduced4 ,the hymns of the primitive epoch1 from ,hilary to ,gregory the ,great1 for the most part retained their places 7especially in the offices for every day of the week72 and there remained altogether from seventy to eighty of earlier date than the #aath century4 ,those1 however1 which were so retained were freely altered1 and by no means generally improved4 ,the revisers appointed by ,pope ,urban 7three learned ,jesuits--,strada1 ,gallucci and ,petrucci7 professed to have made as few changes as possible in the works of ,ambrose1 ,gregory1 ,prudentius1 ,sedulius1 ,fortunatus and other poets of great name4 ,but some changes1 even in those works1 were made with considerable boldness2 and the pope1 in the constitution by which his new book was promulgated1 boasted that1 with the exception of a very small number 7'perpaucis'71 which were either prose or merely rhythmical1 all the hymns had been made conformable to the laws of prosody and ,latinity1 those which could not be corrected by any milder method being entirely rewritten4 ,the latter fate befel1 among others1 the beautiful ,urbs beata ,hierusalem1 which now assumed the form 7to many1 perhaps1 better known71 of ,caelestis urbs ,jerusalem4 ,of the very few which were spared1 the chief were ,ave maris stella 7,gentle star of ocean71 ,dies ,irae1 ,stabat ,mater dolorosa1 the hymns of ,thomas ,aquinas1 two of ,st ,bernard and one ,ambrosian hymn1 ,jesu nostra ,redemptio 7,o ,jesu1 our ,redemption71 which approaches nearer than others to the tone of ,st ,bernard4 ,a then recent hymn of ,st ,francis ,xavier1 with scarcely enough merit of any kind to atone for its neglect of prosody1 ,o ,deus1 ego amo ,te 7,o ,god1 ,i love ,thee1 not because71 was at the same time introduced without change4 ,this hymnary of ,pope ,urban ,,viii4 is now in general use throughout the ,roman ,communion4 ,parisian revisions4 ,the ,parisian hymnary underwent three revisions--the first in #aebg1 when a new ,psaltery with hymns was issued4 ,in this such changes only were made as the revisers thought justifiable upon the principle of correcting supposed corruptions of the original text4 ,of these1 the transposition1 ,urbs ,jerusalem beata1 instead of ,urbs beata ,hierusalem1 may be taken as a typical example4 ,the next revision was in #afgj-afhj1 under ,cardinal ,prfixe1 preceptor of ,louis ,,xiv41 and ,francis ,harlay1 successively archbishops of ,paris1 who employed for this purpose ,claude ,santeul1 of the monastery of ,st ,magloire1 and1 through him1 obtained the assistance of other ,french scholars1 including his more celebrated brother1 ,jean ,baptiste ,santeul1 of the abbey of ,st ,victor--better known as ,santolius ,victorinus4 ,the third and final revision was completed in #agce1 under the primacy of ,cardinal ,archbishop de ,vintimille1 who engaged for it the services of ,charles ,coffin1 then rector of the university of ,paris4 ,many old hymns were omitted in ,archbishop ,harlay's ,breviary1 and a large number of new compositions1 by the ,santeuls and others1 was introduced4 ,it still1 however1 retained in their old places 7without further changes than had been made in #aebg7 about seventy of earlier date than the #aath century--including thirty-one ,ambrosian1 one by ,hilary1 eight by ,prudentius1 seven by ,fortunatus1 three by ,paul the ,deacon1 two each by ,sedulius1 ,elpis1 ,gregory and ,hrabanus ,maurus1 ,veni ,creator and ,urbs ,jerusalem beata4 ,most of these disappeared in #agce1 although ,cardinal ,vintimille1 in his preface1 professed to have still admitted the old hymns1 except when the new were better--7veteribus hymnis locus datus est1 nisi quibus1 ob sententiarum vim1 elegantiam verborum1 et teneriores pietatis sensus1 recentiores anteponi satius visum est74 ,the number of the new was1 at the same time1 very largely increased4 ,only twenty-one more ancient than the #afth century remained1 of which those belonging to the primitive epoch were but eight1 viz4 four ,ambrosian1 two by ,fortunatus and one each by ,prudentius and ,gregory4 ,the number of ,jean ,baptiste ,santeul's hymns rose to eighty-nine2 those by ,coffin--including some old hymns1 e4g4 ,jam lucis orto sidere 7,once more the sun is beaming bright71 which he substantially re-wrote--were eighty-three2 those of other modern ,french writers1 ninety-seven4 ,whatever opinion may be entertained of the principles on which these ,roman and ,parisian revisions proceeded1 it would be unjust to deny very high praise as hymn-writers to several of their poets1 especially to ,coffin and ,jean ,baptiste ,santeul4 ,the noble hymn by ,coffin1 beginning-- ,o luce qui mortalibus ,o ,thou who in the light dost dwell1 ,lates inaccessa1 ,deus1 ,to mortals unapproachable1 ,praesente quo sancti tremunt ,where angels veil them from ,thy rays1 ,nubuntque vultus angeli1 ,and tremble as they gaze1 and several others of his works1 breathe the true ,ambrosian spirit2 and though ,santeul 7generally esteemed the better poet of the two7 delighted in alcaics1 and did not greatly affect the primitive manner1 there can be no question as to the excellence of such hymns as his ,fumant ,sabaeis templa vaporibus 7,sweet incense breathes around71 ,stupete gentes1 fit ,deus hostia 7,tremble1 ye ,gentile lands71 ,hymnis dum resonat curia caelitum 7,ye in the house of heavenly morn71 and ,templi sacratas pande1 ,sion1 fores 7,o ,sion1 open wide thy gates74 ,it is a striking testimony to the merits of those writers that such accomplished translators as the ,rev4 ,isaac ,williams and the ,rev4 ,john ,chandler appear 7from the title-page of the latter1 and the prefaces of both7 to have supposed their hymns to be ancient and primitive4 ,among the other authors associated with them1 perhaps the first place is due to the ,abb ,besnault1 of ,sens1 who contributed to the book of #agce the ,urbs beata vera pacis ,visio ,jerusalem1 in the opinion of ,neale much superior to the ,caelestis urbs ,jerusalem of the ,roman ,breviary4 ,this stood side by side with the ,urbs ,jerusalem beata of #aebg 7in the office for the dedication of churches7 till #ahbb1 when the older form was at last finally excluded by ,archbishop de ,quelen4 ,the ,parisian ,breviary of #agce remained in use till the national ,french service-books were superseded 7as they have lately been1 generally1 if not universally7 by the ,roman4 ,almost all ,french dioceses followed1 not indeed the ,breviary1 but the example1 of ,paris2 and before the end of the #ahth century the ancient ,latin hymnody was all but banished from ,france4 ,modern ,latin hymns4 ,in some parts of ,germany1 after the ,reformation1 ,latin hymns continued to be used even by ,protestants4 ,this was the case at ,halberstadt until quite a recent date4 ,in ,england1 a few are still occasionally used in the older universities and colleges4 ,some1 also1 have been composed in both countries since the ,reformation4 ,the ,carmina lyrica of ,johann ,jakob ,balde1 a native of ,alsace1 and a ,jesuit priest in ,bavaria1 have received high commendation from very eminent ,german critics1 particularly ,herder and ,augustus ,schlegel4 ,some of the ,latin hymns of ,william ,alard 7#aegb-afde71 a ,protestant refugee from ,belgium1 and pastor in ,holstein1 have been thought worthy of a place in ,archbishop ,trench's selection4 ,two by ,w4 ,petersen 7printed at the end of ,haberkorn's supplement to ,jacobi's ,psalmodia ,germanica7 are good in different ways--one1 ,jesu dulcis amor meus 7,jesus1 ,thee my soul doth love71 being a gentle melody of spiritual devotion1 and the other1 entitled ,spes ,sionis1 violently controversial against ,rome4 ,an ,english hymn of the #agth century1 in the ,ambrosian style1 ,te ,deum ,patrem colimus 7,almighty ,father1 just and good71 is sung on every ,may-,day morning by the choristers of ,magdalen ,college1 ,oxford1 from the top of the tower of their chapel2 and another in the style of the ,renaissance1 of about the same date1 ,te de profundis1 summe ,rex 7,thee from the depths1 ,almighty ,king71 long formed part of a grace formerly sung by the scholars of ,winchester ,college4 ,luther4 #e4 ,german ,hymnody4--,luther was a proficient in and a lover of music4 ,he desired 7as he says in the preface to his hymn-book of #aede7 that this beautiful ornament might in a right manner serve the great ,creator and ,his ,christian people4 ,the persecuted ,bohemian or ,hussite ,church1 then settled on the borders of ,moravia under the name of ,united ,brethren1 had sent to him1 on a mission in #aebb1 ,michael ,weiss1 who not long afterwards published a number of ,german translations from old ,bohemian hymns 7known as those of the ,bohemian ,brethren71 with some of his own4 ,these ,luther highly approved and recommended4 ,he himself1 in #aebb1 published a small volume of eight hymns1 which was enlarged to #fc in #aebg1 and to #abe in #aede4 ,he had formed what he called a house choir of musical friends1 to select such old and popular tunes 7whether secular or ecclesiastical7 as might be found suitable1 and to compose new melodies1 for church use4 ,his fellow labourers in this field 7besides ,weiss7 were ,justus ,jonas1 his own especial colleague2 ,paul ,eber1 the disciple and friend of ,melanchthon2 ,john ,walther1 choirmaster successively to several ,german princes1 and professor of arts1 c41 at ,wittenberg2 ,nicholas ,decius1 who from a monk became a ,protestant teacher in ,brunswick1 and translated the ,gloria in ,excelsis1 c42 and ,paul ,speratus1 chaplain to ,duke ,albert of ,prussia in #aebe4 ,some of their works are still popular in ,germany4 ,weiss's ,funeral ,hymn1 ,nun lasst uns den ,leib begraben 7,now lay we calmly in the grave72 ,eber's ,herr ,jesu ,christ1 wahr ,mensch und ,gott 7,lord ,jesus ,christ1 true ,man and ,god71 and ,wenn wir in hchsten ,nthen sein 7,when in the hour of utmost need72 ,walther's ,new ,heavens and new ,earth 7,now fain my joyous heart would sing72 ,decius's ,to ,god on high be thanks and praise2 and ,speratus's ,salvation now has come for all1 are among those which at the time produced the greatest effect1 and are still best remembered4 ,luther's own hymns1 thirty-seven in number 7of which about twelve are translations or adaptations from ,latin originals71 are for the principal ,christian seasons2 on the sacraments1 the church1 grace1 death1 c42 and paraphrases of seven psalms1 of a passage in ,isaiah1 and of the ,lord's ,prayer1 ,ten ,commandments1 ,creed1 ,litany and ,te ,deum4 ,there is also a very touching and stirring song on the martyrdom of two youths by fire at ,brussels1 in #aebc-aebd4 ,homely and sometimes rugged in form1 and for the most part objective in tone1 they are full of fire1 manly simplicity and strong faith4 ,three rise above the rest4 ,one for ,christmas1 ,vom ,himmel hoch da komm ich her 7,from ,heaven above to earth ,i come71 has a reverent tenderness1 the influence of which may be traced in many later productions on the same subject4 ,that on salvation through ,christ1 of a didactic character1 ,nun freuet euch1 lieben ,christen g'mein 7,dear ,christian people1 now rejoice71 is said to have made many conversions1 and to have been once taken up by a large congregation to silence a ,roman ,catholic preacher in the cathedral of ,frankfort4 ,pre-eminent above all is the celebrated paraphrase of the #dfth ,psalm3 ,ein' feste ,burg ist unser ,gott 7,a sure stronghold our ,god is ,he7--the production 7as ,ranke says7 of the moment in which ,luther1 engaged in a conflict with a world of foes1 sought strength in the consciousness that he was defending a divine cause which could never perish4 ,carlyle compares it to a sound of ,alpine avalanches1 or the first murmur of earthquakes4 ,heine called it the ,marseillaise of the ,reformation4 ,luther spent several years in teaching his people at ,wittenberg to sing these hymns1 which soon spread over ,germany4 ,without adopting the hyperbolical saying of ,coleridge1 that ,luther did as much for the ,reformation by his hymns as by his translation of the ,bible1 it may truly be affirmed1 that1 among the secondary means by which the success of the ,reformation was promoted1 none was more powerful4 ,they were sung everywhere--in the streets and fields as well as the churches1 in the workshop and the palace1 by children in the cottage and by martyrs on the scaffold4 ,it was by them that a congregational character was given to the new ,protestant worship4 ,this success they owed partly to their metrical structure1 which1 though sometimes complex1 was recommended to the people by its ease and variety2 and partly to the tunes and melodies 7many of them already well known and popular7 to which they were set4 ,they were used as direct instruments of teaching1 and were therefore1 in a large measure1 didactic and theological2 and it may be partly owing to this cause that ,german hymnody came to deviate1 so soon and so generally as it did1 from the simple idea expressed in the ancient ,augustinian definition1 and to comprehend large classes of compositions which1 in most other countries1 would be thought hardly suitable for church use4 ,followers of ,luther ,the principal hymn-writers of the ,lutheran school1 in the latter part of the #afth century1 were ,nikolaus ,selnecker1 ,herman and ,hans ,sachs1 the shoemaker of ,nuremberg1 also known in other branches of literature4 ,all these wrote some good hymns4 ,they were succeeded by men of another sort1 to whom ,f4 ,a4 ,cunz gives the name of master-singers1 as having raised both the poetical and the musical standard of ,german hymnody3--,bartholomus ,ringwaldt1 ,ludwig ,helmbold1 ,johannes ,pappus1 ,martin ,schalling1 ,rutilius and ,sigismund ,weingartner4 ,the principal topics of their hymns 7as if with some foretaste of the calamities which were soon to follow7 were the vanity of earthly things1 resignation to the ,divine will1 and preparation for death and judgment4 ,the well-known ,english hymn1 ,great ,god1 what do ,i see and hear1 is founded upon one by ,ringwaldt4 ,of a quite different character were two of great beauty and universal popularity1 composed by ,philip ,nicolai1 a ,westphalian pastor1 during a pestilence in #aeig1 and published by him1 with fine chorales1 two years afterwards4 ,one of these 7the ,sleepers wake6 a voice is calling1 of ,mendelssohn's oratorio1 ,st ,paul7 belongs to the family of ,advent or ,new ,jerusalem hymns4 ,the other1 a ,song of the believing soul concerning the ,heavenly ,bridegroom 7,wie schn leucht't uns der ,morgenstern--,o morning ,star1 how fair and bright71 became the favourite marriage hymn of ,germany4 ,period of ,thirty ,years' ,war4 ,the hymns produced during the ,thirty ,years' ,war are characteristic of that unhappy time1 which 7as ,miss ,winkworth says7 caused religious men to look away from this world1 and made their songs more and more expressive of personal feelings4 ,in point of refinement and graces of style1 the hymn-writers of this period excelled their predecessors4 ,their taste was chiefly formed by the influence of ,martin ,opitz1 the founder of what has been called the first ,silesian school of ,german poetry1 who died comparatively young in #afci1 and who1 though not of any great original genius1 exercised much power as a critic4 ,some of the best of these works were by men who wrote little4 ,in the famous battle-song of ,gustavus ,adolphus1 published 7#afca7 after the victory of ,breitenfeld1 for the use of his army1 ,verzage nicht du ,huflein klein 7,fear not1 ,o little flock1 the foe71 we have almost certainly a composition of the hero-king himself1 the versification corrected by his chaplain ,jakob ,fabricius 7#aeic-afed7 and the music composed by ,michael ,altenburg1 whose name has been given to the hymn4 ,this1 with ,luther's paraphrase of the #fgth ,psalm1 was sung by ,gustavus and his soldiers before the battle of ,ltzen in #afcb4 ,two very fine hymns1 one of prayer for deliverance and peace1 the other of trust in ,god under calamities1 were written about the same time by ,matthus ,lwenstern1 a saddler's son1 poet1 musician and statesman1 who was ennobled after the peace by the emperor ,ferdinand ,,iii4 ,martin ,rinckhart1 in #afcf1 wrote the ,chorus of ,god's faithful children 7,nun danket alle ,gott--,now thank we all our ,god71 introduced by ,mendelssohn in his ,lobgesang1 which has been called the ,te ,deum of ,germany1 being usually sung on occasions of public thanksgiving4 ,weissel1 in #afce1 composed a beautiful ,advent hymn 7,lift up your heads1 ye mighty gates71 and ,j4 ,m4 ,meyfart1 professor of theology at ,erfurt1 in #afdb1 a fine adaptation of the ancient ,urbs beata ,hierusalem4 ,the hymn of trust in ,providence by ,george ,neumark1 librarian to that duke of ,weimar 7,wer nur den lieben ,gott lsst walten--,leave ,god to order all thy ways71 is scarcely1 if at all1 inferior to that of ,paul ,gerhardt on the same theme4 ,paul ,flemming1 a great traveller and lover of nature1 who died in #afci1 also wrote excellent compositions1 coloured by the same tone of feeling2 and some1 of great merit1 were composed1 soon after the close of the war1 by ,louisa ,henrietta1 electress of ,brandenburg1 granddaughter of the famous admiral ,coligny1 and mother of the first king of ,prussia4 ,with these may be classed 7though of later date7 a few striking hymns of faith and prayer under mental anxiety1 by ,anton ,ulrich1 duke of ,brunswick4 ,rist4 ,dach4 ,the most copious1 and in their day most esteemed1 hymn-writers of the first half of the #agth century1 were ,johann ,heermann and ,johann ,rist4 ,heermann1 a pastor in ,silesia1 the theatre 7in a peculiar degree7 of war and persecution1 experienced in his own person a very large share of the miseries of the time1 and several times narrowly escaped a violent death4 ,his ,devoti musica cordis1 published in #afcj1 reflects the feelings natural under such circumstances4 ,with a correct style and good versification1 his tone is subjective1 and the burden of his hymns is not praise1 but prayer4 ,among his works 7which enter largely into most ,german hymn-books71 two of the best are the ,song of ,tears and the ,song of ,comfort1 translated by ,miss ,winkworth in her ,christian ,singers of ,germany4 ,rist published about #fjj hymns1 pressed out of him1 as he said1 by the cross4 ,he was a pastor1 and son of a pastor1 in ,holstein1 and lived after the peace to enjoy many years of prosperity1 being appointed poet-laureate to the emperor and finally ennobled4 ,the bulk of his hymns1 like those of other copious writers1 are of inferior quality2 but some1 particularly those for ,advent1 ,epiphany1 ,easter ,eve and on ,angels1 are very good4 ,they are more objective than those of ,heermann1 and written1 upon the whole1 in a more manly spirit4 ,next to ,heermann and ,rist in fertility of production1 and above them in poetical genius1 was ,simon ,dach1 professor of poetry at ,knigsberg1 who died in #afei4 ,miss ,winkworth ranks him high among ,german poets1 for the sweetness of form and depth of tender contemplative emotion to be found in his verses4 ,gerhardt4 ,franck4 ,scheffler4 ,the fame of all these writers was eclipsed in the latter part of the same century by three of the greatest hymnographers whom ,germany has produced--,paul ,gerhardt 7#afjd-afgf71 ,johann ,franck 7#afah-afgg7 and ,johann ,scheffler 7#afbd-afgg71 the founder of the second ,silesian school1 who assumed the name of ,angelus ,silesius4 ,gerhardt is by universal consent the prince of ,lutheran poets4 ,his compositions1 which may be compared1 in many respects1 to those of the ,christian ,year1 are lyric poems1 of considerable length1 rather than hymns1 though many hymns have been taken from them4 ,they are1 with few exceptions1 subjective1 and speak the language of individual experience4 ,they occupy a middle ground between the masculine simplicity of the old ,lutheran style and the highly wrought religious emotion of the later pietists1 towards whom they on the whole incline4 ,being nearly all excellent1 it is not easy to distinguish among the #abc those which are entitled to the highest praise4 ,two1 which were written one during the war and the other after the conclusion of peace1 ,zeuch ein zu deinen ,thoren 7,come to ,thy temple here on earth71 and ,gottlob1 nun ist erschollen 7,thank ,god1 it hath resounded71 are historically interesting4 ,of the rest1 one is well known and highly appreciated in ,english through ,wesley's translation1 ,commit thou all thy ways2 and the evening and spring-tide hymns 7,now all the woods are sleeping and ,go forth1 my heart1 and seek delight7 show an exquisite feeling for nature2 while nothing can be more tender and pathetic than ,du bist zwar mein und bleibest mein 7,thou'rt mine1 yes1 still thou art mine own71 on the death of his son4 ,franck1 who was burgomaster of ,guben in ,lusatia1 has been considered by some second only to ,gerhardt4 ,if so1 it is with a great distance between them4 ,his approach to the later pietists is closer than that of ,gerhardt4 ,his hymns were published1 under the title of ,geistliche und weltliche ,gedichte1 in #afgd1 some of them being founded on ,ambrosian and other ,latin originals4 ,miss ,winkworth gives them the praise of a condensed and polished style and fervid and impassioned thought4 ,it was after his conversion to ,roman ,catholicism that ,scheffler adopted the name of ,angelus ,silesius1 and published in #afeg his hymns1 under a fantastic title1 and with a still more fantastic preface4 ,their keynote is divine love2 they are enthusiastic1 intense1 exuberant in their sweetness1 like those of ,st ,bernard among medieval poets4 ,an adaptation of one of them1 by ,wesley1 ,thee will ,i love1 my ,strength1 my ,tower1 is familiar to ,english readers4 ,those for the first ,sunday after ,epiphany1 for ,sexagesima ,sunday and for ,trinity ,sunday1 in ,lyra ,germanica1 are good examples of his excellences1 with few of his defects4 ,his hymns are generally so free from the expression1 or even the indirect suggestion1 of ,roman ,catholic doctrine1 that it has been supposed they were written before his conversion1 though published afterwards4 ,the evangelical churches of ,germany found no difficulty in admitting them to that prominent place in their services which they have ever since retained4 ,pietists4 ,towards the end of the #agth century1 a new religious school arose1 to which the name of ,pietists was given1 and of which ,philipp ,jakob ,spener was esteemed the founder4 ,he and his pupils and successors1 ,august ,hermann ,francke and ,anastasius ,freylinghausen1 all wrote hymns4 ,spener's hymns are not remarkable1 and ,francke's are not numerous4 ,freylinghausen was their chief singer2 his rhythm is lively1 his music florid2 but1 though his book attained extraordinary popularity1 he was surpassed in solid merit by other less fertile writers of the same school4 ,the ,auf hinauf zu deiner ,freude 7,up1 yes1 upward to thy gladness7 of ,schade may recall to an ,english reader a hymn by ,seagrave1 and more than one by ,lyte2 the ,malabarian hymn 7as it was called by ,jacobi7 of ,johann ,schtz1 ,all glory to the ,sovereign ,good1 has been popular in ,england as well as ,germany2 and one of the most exquisite strains of pious resignation ever written is ,whate'er my ,god ordains is right1 by ,samuel ,rodigast4 ,neander4 ,joachim ,neander1 a schoolmaster at ,dsseldorf1 and a friend of ,spener and ,schtz 7who died before the full development of the ,pietistic school71 was the first man of eminence in the ,reformed or ,calvinistic ,church who imitated ,lutheran hymnody4 ,this he did1 while suffering persecution from the elders of his own church for some other religious practices1 which he had also learnt from ,spener's example4 ,as a poet1 he is sometimes deficient in art2 but there is feeling1 warmth and sweetness in many of his ,bundeslieder or ,songs of the ,covenant1 and they obtained general favour1 both in the ,reformed and in ,lutheran congregations4 ,the ,summer ,hymn 7,o ,thou true ,god alone7 and that on the glory of ,god in creation 7,lo1 heaven and earth and sea and air7 are instances of his best style4 ,schmolke4 ,dessler4 ,hiller4 ,arnold4 ,tersteegen4 ,zinzendorf4 ,with the ,pietists may be classed ,benjamin ,schmolke and ,dessler1 representatives of the ,orthodox division of ,spener's school2 ,philipp ,friedrich ,hiller1 their leading poet in ,south ,germany2 ,gottfried ,arnold and ,gerhard ,tersteegen1 who were practically independent of ecclesiastical organization1 though connected1 one with the ,orthodox and the other with the ,reformed churches2 and ,nikolaus ,ludwig1 ,graf von ,zinzendorf4 ,schmolke1 a pastor in ,silesia1 called the ,silesian ,rist 7#afgb-agcg71 was perhaps the most voluminous of all ,german hymn-writers4 ,he wrote #aahh religious poems and hymns1 a large proportion of which do not rise above mediocrity4 ,his style1 if less refined1 is also less subjective and more simple than that of most of his contemporaries4 ,among his best and most attractive works1 which indeed1 it would be difficult to praise too highly1 are the ,hosianna ,david's ,sohn1 for ,palm ,sunday--much resembling a shorter hymn by ,jeremy ,taylor2 and the ,ascension1 ,whitsuntide and ,sabbath hymns--,heavenward doth our journey tend1 ,come deck our feast to-day1 and ,light of light1 enlighten me4 ,dessler was a greater poet than ,schmolke4 ,few hymns1 of the subjective kind1 are better than his ,i will not let ,thee go1 ,thou ,help in time of need1 ,o ,friend of souls1 how well is me1 and ,now1 the pearly gates unfold4 ,hiller 7#afii-agfi71 was a pastor in ,wrttemberg who1 falling into ill-health during the latter part of his ministry1 published a ,geistliche ,liederhstlein in a didactic vein1 with more taste than power1 but 7as ,miss ,winkworth says7 in a tone of deep1 thoughtful1 practical piety4 ,they were so well adapted to the wants of his people that to this day ,hiller's ,casket is prized1 next to their ,bibles1 by the peasantry of ,wrttemberg2 and the numerous emigrants from that part of ,germany to ,america and other foreign countries generally take it with them wherever they go4 ,arnold1 a professor at ,giessen1 and afterwards a pastor in ,brandenburg1 was a man of strong will1 uncompromising character and austere views of life1 intolerant and controversial towards those whose doctrine or practice he disapproved1 and more indifferent to separatism and sectarianism than the orthodox generally thought right4 ,his hymns1 like those of ,augustus ,m4 ,toplady1 whom in these respects he resembled1 unite with considerable strength more gentleness and breadth of sympathy than might be expected from a man of such a character4 ,tersteegen 7#afig-agfi71 who never formally separated himself from the ,reformed communion1 in which he was brought up1 but whose sympathies were with the ,moravians and with ,zinzendorf1 was1 of all the more copious ,german hymn-writers after ,luther1 perhaps the most remarkable man4 ,pietist1 mystic and missionary1 he was also a great religious poet4 ,his #aaa hymns were published ,in #agca1 in a volume called ,geistlicher ,blumengrtlein inniger ,seelen4 ,they are intensely individual1 meditative and subjective4 ,wesley's adaptations of two--,lo6 ,god is here2 let us adore1 and ,thou hidden ,love of ,god1 whose source--are well known4 ,among those translated by ,miss ,winkworth1 ,o ,god1 ,o ,spirit1 ,light of all that live1 and ,come1 brethren1 let us go1 are specimens which exhibit favourably his manner and power4 ,miss ,cox speaks of him as a gentle heaven-inspired soul1 whose hymns are the reflection of a heavenly1 happy life1 his mind being full of a child-like simplicity2 and his own poem on the child-character1 which ,miss ,winkworth has appropriately connected with ,innocents' day 7,dear ,soul1 couldst thou become a child7--one of his best compositions1 exquisitely conceived and expressed--shows that this was in truth the ideal which he sought to realize4 ,the hymns of ,zinzendorf are often disfigured by excess in the application of the language and imagery of human affections to divine objects2 and this blemish is also found in many later ,moravian hymns4 ,but one hymn1 at least1 of ,zinzendorf may be mentioned with unqualified praise1 as uniting the merits of force1 simplicity and brevity--,jesu1 geh voran 7,jesus1 lead the way71 which is taught to most children of religious parents in ,germany4 ,wesley's ,jesus1 ,thy blood and righteousness is a translation from ,zinzendorf4 ,gellert4 ,the transition from ,tersteegen and ,zinzendorf to ,gellert and ,klopstock marks strongly the reaction against ,pietism which took place towards the middle of the #ahth century4 ,the ,geistlichen ,oden und ,lieder of ,christian ,f4 ,gellert were published in #ageg1 and are said to have been received with an enthusiasm almost like that which greeted ,luther's hymns on their first appearance4 ,it is a proof of the moderation both of the author and of his times that they were largely used1 not only by ,protestant congregations1 but in those ,german ,roman ,catholic churches in which vernacular services had been established through the influence of the emperor ,joseph ,,ii4 ,they became the model which was followed by most succeeding hymn-writers1 and exceeded all others in popularity till the close of the century1 when a new wave of thought was generated by the movement which produced the ,french ,revolution4 ,since that time they have been1 perhaps1 too much depreciated4 ,they are1 indeed1 cold and didactic1 as compared with ,scheffler or ,tersteegen2 but there is nevertheless in them a spirit of genuine practical piety2 and1 if not marked by genius1 they are pure in taste1 and often terse1 vigorous and graceful4 ,klopstock4 ,klopstock1 the author of the ,messiah1 cannot be considered great as a hymn-writer1 though his ,sabbath ,hymn 7of which there is a version in ,hymns from the ,land of ,luther7 is simple and good4 ,generally his hymns 7ten of which are translated in ,sheppard's ,foreign ,sacred ,lyre7 are artificial and much too elaborate4 ,fouqu4 ,of the romantic school1 which came in with the ,french ,revolution1 the two leading writers are ,friedrich ,leopold von ,hardenberg1 called ,novalis1 and ,friedrich de la ,motte ,fouqu1 the celebrated author of ,undine and ,sintram--both romance-writers1 as well as poets4 ,the genius of ,novalis was early lost to the world2 he died in #ahja1 not thirty years old4 ,some of his hymns are very beautiful2 but even in such works as ,though all to ,thee were faithless1 and ,if only ,he is mine1 there is a feeling of insulation and of despondency as to good in the actual world1 which was perhaps inseparable from his ecclesiastical idealism4 ,fouqu survived till #ahdc4 ,in his hymns there is the same deep flow of feeling1 richness of imagery and charm of expression which distinguishes his prose works4 ,the two missionary hymns--,thou1 solemn ,ocean1 rollest to the strand1 and ,in our sails all soft and sweetly--and the exquisite composition which finds its motive in the gospel narrative of blind ,bartimeus1 ,was du vor tausend ,jahren 7finely translated both by ,miss ,winkworth and by ,miss ,cox71 are among the best examples4 ,spitta4 ,the later ,german hymn-writers of the #aith century belong1 generally1 to the revived ,pietistic school4 ,some of the best1 ,johann ,baptist von ,albertini1 ,friedrich ,adolf ,krummacher1 and especially ,karl ,johann ,philipp ,spitta 7#ahja-ahei7 have produced works not unworthy of the fame of their nation4 ,mr ,massie1 the able translator of ,spitta's ,psalter und ,harfe 7,leipzig1 #ahcc71 speaks of it as having obtained for him in ,germany a popularity only second to that of ,paul ,gerhardt4 ,in ,spitta's poems 7for such they generally are1 rather than hymns7 the subjective and meditative tone is tempered1 not ungracefully1 with a didactic element2 and they are not disfigured by exaggerated sentiment1 or by a too florid and rhetorical style4 #f4 ,british ,hymnody4--,after the ,reformation1 the development of hymnody was retarded1 in both parts of ,great ,britain1 by the example and influence of ,geneva4 ,archbishop ,cranmer appears at one time to have been disposed to follow ,luther's course1 and to present to the people1 in an ,english dress1 some at least of the hymns of the ancient church4 ,in a letter to ,king ,henry ,,viii4 7,october #g1 #aedd71 among some new processions which he had himself translated1 into ,english1 he mentions the ,easter hymn1 ,salve1 festa dies1 toto memorabilis aevo 7,hail1 glad day1 to be joyfully kept through all generations71 of ,fortunatus4 ,in the ,primer of #aece 7by ,marshall7 and the one of #aeci 7by ,bishop ,hilsey of ,rochester1 published by order of the vicar-general ,cromwell7 there had been several rude ,english hymns1 none of them taken from ancient sources4 ,king ,henry's ,primer of #aede 7commanded by his injunction of the #fth of ,may #aede to be used throughout his dominions7 was formed on the model of the daily offices of the ,breviary2 and it contains ,english metrical translations from some of the best-known ,ambrosian and other early hymns4 ,but in the succeeding reign different views prevailed4 ,a new direction had been given to the taste of the ,reformed congregations in ,france and ,switzerland by the ,french metrical translation of the ,old ,testament ,psalms1 which appeared about #aedj4 ,this was the joint work of ,clement ,marot1 valet or groom of the chamber to ,francis ,i41 and ,theodore ,beza1 then a mere youth1 fresh from his studies at ,orleans4 ,marot's ,psalms4 ,marot's psalms were dedicated to the ,french king and the ladies of ,france1 and1 being set to popular airs1 became fashionable4 ,they were sung by ,francis himself1 the queen1 the princesses and the courtiers1 upon all sorts of secular occasions1 and also1 more seriously and religiously1 by the citizens and the common people4 ,they were soon perceived to be a power on the side of the ,reformation4 ,calvin1 who had settled at ,geneva in the year of ,marot's return to ,paris1 was then organizing his ecclesiastical system4 ,he rejected the hymnody of the breviaries and missals1 and fell back upon the idea1 anciently held by ,paul of ,samosata1 and condemned by the fourth council of ,toledo1 that whatever was sung in churches ought to be taken out of the ,scriptures4 ,marot's ,psalter1 appearing thus opportunely1 was introduced into his new system of worship1 and appended to his catechism4 ,on the other hand1 it was interdicted by the ,roman ,catholic priesthood4 ,thus it became a badge to the one party of the reformed profession1 and to the other of heresy4 ,sternhold and ,hopkins4 ,the example thus set produced in ,england the translation commonly known as the ,old ,version of the ,psalms4 ,it was begun by ,thomas ,sternhold1 whose position in the household of ,henry ,,viii41 and afterwards of ,edward ,,vi41 was similar to that of ,marot with ,francis ,i41 and whose services to the former of those kings were rewarded by a substantial legacy under his will4 ,sternhold published versions of nineteen ,psalms1 with a dedication to ,king ,edward1 and died soon afterwards4 ,a second edition appeared in #aeea1 with eighteen more ,psalms added1 of ,sternhold's translating1 and seven others by ,john ,hopkins1 a ,suffolk clergyman4 ,the work was continued during ,queen ,mary's reign by ,british refugees at ,geneva1 the chief of whom were ,william ,whittingham1 afterwards dean of ,durham1 who succeeded ,john ,knox as minister of the ,english congregation there1 and ,william ,kethe or ,keith1 said by ,strype to have been a ,scotsman4 ,they published at ,geneva in #aeef a service-book1 containing fifty-one ,english metrical psalms1 which number was increased1 in later editions1 to eighty-seven4 ,on the accession of ,queen ,elizabeth1 this ,genevan ,psalmody was at once brought into use in ,england--first 7according to a letter of ,bishop ,jewell to ,peter ,martyr1 dated #eth ,march #aefj7 in one ,london church1 from which it quickly spread to others both in ,london and in other cities4 ,jewell describes the effect produced by large congregations1 of as many as #fjjj persons1 young and old1 women and children1 singing it after the sermons at ,st ,paul's ,cross--adding1 ,id sacrificos et diabolum aegre habet2 vident enim sacras conciones hoc pacto profundius descendere in hominum animos4 ,the first edition of the completed ,old ,version 7containing forty ,psalms by ,sternhold1 sixty-seven by ,hopkins1 fifteen by ,whittingham1 six by ,kethe and the rest by ,thomas ,norton the dramatist1 ,robert ,wisdom1 ,john ,marckant and ,thomas ,churchyard7 appeared in #aefb4 ,in the meantime1 the ,books of ,common ,prayer1 of #aedi1 #aeeb and #aeei1 had been successively established as law by the acts of uniformity of ,edward ,,vi4 and ,queen ,elizabeth4 ,in these no provision was made for the use of any metrical psalm or hymn on any occasion whatever1 except at the consecration of bishops and the ordination of priests1 in which offices 7first added in #aeeb7 an ,english version of ,veni ,creator 7the longer of the two now in use7 was appointed to be said or sung4 ,the canticles1 ,te ,deum1 ,benedicite1 the ,nicene and ,athanasian ,creeds1 the ,gloria in ,excelsis1 and some other parts of the communion and other special offices were also directed to be said or sung2 and1 by general rubrics1 the chanting of the whole service was allowed4 ,the silence1 however1 of the rubrics in these books as to any other singing was not meant to exclude the use of psalms not expressly appointed1 when they could be used without interfering with the prescribed order of any service4 ,it was expressly provided by ,king ,edward's first act of uniformity 7by later acts made applicable to the later books7 that it should be lawful for all men1 as well in churches1 chapels1 oratories or other places1 to use openly any psalms or prayers taken out of the ,bible1 at any due time1 not letting or omitting thereby the service1 or any part thereof1 mentioned in the book4 ,and ,queen ,elizabeth1 by one of the injunctions issued in the first year of her reign1 declared her desire that the provision made1 in divers collegiate and also some parish churches1 for singing in the church1 so as to promote the laudable service of music1 should continue4 ,after allowing the use of a modest and distinct song in all parts of the common prayers of the church1 so that the same may be as plainly understanded as if it were read without singing1 the injunction proceeded thus--,and yet1 nevertheless1 for the comforting of such that delight in music1 it may be permitted that in the beginning or in the end of the ,common ,prayer1 either at morning or evening1 there may be sung an hymn1 or such like song to the praise of ,almighty ,god1 in the best sort of melody and music that may be conveniently devised1 having respect that the sentence 7i4e4 sense7 of hymn may be understanded and perceived4 ,the ,old ,version1 when published 7by ,john ,daye1 for the ,stationers' ,company1 cum gratia et privilegio ,regiae ,majestatis71 bore upon the face of it that it was newly set forth1 and allowed to be sung of the people in churches1 before and after morning and evening prayer1 as also before and after the sermon4 ,the question of its authority has been at different times much debated1 chiefly by ,peter ,heylyn and ,thomas ,warton on one side 7both of whom disliked and disparaged it71 and by ,william ,beveridge1 bishop of ,st ,asaph1 and the ,rev4 ,h4 ,j4 ,todd on the other4 ,heylyn says1 it was permitted rather than allowed1 which seems to be a distinction without much difference4 ,allowance1 which is all that the book claimed for itself1 is authorization by way of permission1 not of commandment4 ,its publication in that form could hardly have been licensed1 nor could it have passed into use as it did without question1 throughout the churches of ,england1 unless it had been allowed by some authority then esteemed to be sufficient4 ,whether that authority was royal or ecclesiastical does not appear1 nor 7considering the proviso in ,king ,edward's act of uniformity1 and ,queen ,elizabeth's injunctions7 is it very important4 ,no inference can justly be drawn from the inability of inquirers1 in ,heylyn's time or since1 to discover any public record bearing upon this subject1 many public documents of that period having been lost4 ,in this book1 as published in #aefb1 and for many years afterwards1 there were 7besides the versified ,psalms7 eleven metrical versions of the ,te ,deum1 canticles1 ,lord's ,prayer 7the best of which is that of the ,benedicite72 and also ,da pacem1 ,domine1 a hymn suitable to the times1 rendered into ,english from ,luther2 two original hymns of praise1 to be sung before morning and evening prayer2 two penitential hymns 7one of them the humble lamentation of a sinner72 and a hymn of faith1 beginning1 ,lord1 in ,thee is all my trust4 ,in these respects1 and also in the tunes which accompanied the words 7stated by ,dr ,charles ,burney1 in his ,history of ,music1 to be ,german1 and not ,french71 there was a departure from the ,genevan platform4 ,some of these hymns1 and some of the psalms also 7e4g4 those by ,robert ,wisdom1 being alternative versions71 were omitted at a later period2 and many alterations and supposed amendments were from time to time made by unknown hands in the psalms which remained1 so that the text1 as now printed1 is in many places different from that of #aefb4 ,scotch ,psalms4 ,in ,scotland1 the ,general ,assembly of the kirk caused to be printed at ,edinburgh in #aefd1 and enjoined the use of1 a book entitled ,the ,form of ,prayers and ,ministry of the ,sacraments used in the ,english ,church at ,geneva1 approved and received by the ,church of ,scotland2 whereto1 besides that was in the former books1 are also added sundry other prayers1 with the whole ,psalms of ,david in ,english metre4 ,this contained1 from the ,old ,version1 translations of forty ,psalms by ,sternhold1 fifteen by ,whittingham1 twenty-six by ,kethe and thirty-five by ,hopkins4 ,of the remainder two were by ,john ,pulleyn 7one of the ,genevan refugees1 who became archdeacon of ,colchester72 six by ,robert ,pont1 ,knox's son-in-law1 who was a minister of the kirk1 and also a lord of session2 and fourteen signed with the initials ,i4 ,c41 supposed to be ,john ,craig2 one was anonymous1 eight were attributed to ,n41 two to ,m4 and one to ,t4 ,n4 respectively4 ,so matters continued in both churches until the ,civil ,war4 ,during the interval1 ,king ,james ,i4 conceived the project of himself making a new version of the ,psalms1 and appears to have translated thirty-one of them--the correction of which1 together with the translation of the rest1 he entrusted to ,sir ,william ,alexander1 afterwards earl of ,stirling4 ,sir ,william having completed his task1 ,king ,charles ,i4 had it examined and approved by several archbishops and bishops of ,england1 ,scotland and ,ireland1 and caused it to be printed in #afca at the ,oxford ,university ,press1 as the work of ,king ,james2 and1 by an order under the royal sign manual1 recommended its use in all churches of his dominions4 ,in #afcd he enjoined the ,privy ,council of ,scotland not to suffer any other psalms1 of any edition whatever1 to be printed in or imported into that kingdom4 ,in #afcf it was republished1 and was attached to the famous ,scottish service-book1 with which the troubles began in #afcg4 ,it need hardly be added that the king did not succeed in bringing this ,psalter into use in either kingdom4 ,when the ,long ,parliament undertook1 in #afdb1 the task of altering the liturgy1 its attention was at the same time directed to psalmody4 ,it had to judge between two rival translations of the ,psalms--one by ,francis ,rouse1 a member of the ,house of ,commons1 afterwards one of ,cromwell's councillors and finally provost of ,eton2 the other by ,william ,barton1 a clergyman of ,leicester4 ,the ,house of ,lords favoured ,barton1 the ,house of ,commons ,rouse1 who had made much use of the labours of ,sir ,william ,alexander4 ,both versions were printed by order of parliament1 and were referred for consideration to the ,westminster ,assembly4 ,they decided in favour of ,rouse4 ,his version1 as finally amended1 was published in #afdf1 under an order of the ,house of ,commons dated #adth ,november #afde4 ,in the following year it was recommended by the parliament to the ,general ,assembly at ,edinburgh1 who appointed a committee1 with large powers1 to prepare a revised ,psalter1 recommending to their consideration not only ,rouse's book but that of #aefd1 and two other versions 7by ,zachary ,boyd and ,sir ,william ,mure of ,rowallan71 then lately executed in ,scotland4 ,the result of the labours of this committee was the ,paraphrase of the ,psalms1 which1 in #afdi-afej1 by the concurrent authority of the ,general ,assembly and the committee of estates1 was ordered to be exclusively used throughout the church of ,scotland4 ,some use was made in the preparation of this book of the versions to which the attention of the revisers had been directed1 and also of ,barton's2 but its basis was that of ,rouse4 ,it was received in ,scotland with great favour1 which it has ever since retained2 and it is fairly entitled to the praise of striking a tolerable medium between the rude homeliness of the ,old1 and the artificial modernism of the ,new ,english versions--perhaps as great a success as was possible for such an undertaking4 ,sir ,walter ,scott is said to have dissuaded any attempt to alter it1 and to have pronounced it1 with all its acknowledged occasional harshness1 so beautiful1 that any alterations must eventually prove only so many blemishes4 ,no further step towards any authorized hymnody was taken by the kirk of ,scotland till the following century4 ,in ,england1 two changes bearing on church hymnody were made upon the revision of the prayer-book after the ,restoration1 in #affa-affb4 ,one was the addition1 in the offices for consecrating bishops and ordaining priests1 of the shorter version of ,veni ,creator 7,come1 ,holy ,ghost1 our souls inspire71 as an alternative form4 ,the other1 and more important1 was the insertion of the rubric after the third collect1 at morning and evening prayer3 ,in quires and places where they sing1 here followeth the anthem4 ,by this rubric synodical and parliamentary authority was given for the interruption1 at that point1 of the prescribed order of the service by singing an anthem1 the choice of which was left to the discretion of the minister4 ,those actually used1 under this authority1 were for some time only unmetrical passages of scripture1 set to music by ,blow1 ,purcell and other composers1 of the same kind with the anthems still generally sung in cathedral and collegiate churches4 ,but the word anthem had no technical signification which could be an obstacle to the use under this rubric of metrical hymns4 ,tate and ,brady4 ,the ,new ,version of the ,psalms1 by ,dr ,nicholas ,brady and the poet-laureate ,nahum ,tate 7both ,irishmen71 appeared in #afif1 under the sanction of an order in council of ,william ,,iii41 allowing and permitting its use in all such churches1 chapels and congregations as should think fit to receive it4 ,dr ,compton1 bishop of ,london1 recommended it to his diocese4 ,no hymns were then appended to it2 but the authors added a supplement in #agjc1 which received an exactly similar sanction from an order in council of ,queen ,anne4 ,in that supplement there were several new versions of the canticles1 and of the ,veni ,creator2 a variation of the old humble lamentation of a sinner2 six hymns for ,christmas1 ,easter and ,holy ,communion 7all versions or paraphrases of scripture71 which are still usually printed at the end of the prayer-books containing the new version2 and a hymn on the divine use of music--all accompanied by tunes4 ,the authors also reprinted1 with very good taste1 the excellent version of the ,benedicite which appeared in the book of #aefb4 ,of the hymns in this supplement1 one 7,while shepherds watched their flocks by night7 greatly exceeded the rest in merit4 ,it has been ascribed to ,tate1 but it has a character of simplicity unlike the rest of his works4 ,old and new versions compared4 ,the relative merits of the ,old and ,new versions have been very variously estimated4 ,competent judges have given the old the praise1 which certainly cannot be accorded to the new1 of fidelity to the ,hebrew4 ,in both1 it must be admitted1 that those parts which have poetical merit are few and far between2 but a reverent taste is likely to be more offended by the frequent sacrifice1 in the new1 of depth of tone and accuracy of sense to a fluent commonplace correctness of versification and diction1 than by any excessive homeliness in the old4 ,in both1 however1 some psalms1 or portions of psalms1 are well enough rendered to entitle them to a permanent place in the hymn-books--especially the #hth1 and parts of the #ahth ,psalm1 by ,sternhold2 the #egth1 #hdth and #ajjth1 by ,hopkins2 the #bcrd1 #cdth and #cfth1 and part of the #adhth1 by ,tate and ,brady4 ,the judgment which a fastidious critic might be disposed to pass upon both these books may perhaps be considerably mitigated by comparing them with the works of other labourers in the same field1 of whom ,holland1 in his interesting volumes entitled ,psalmists of ,great ,britain1 enumerates above #aej4 ,some of them have been real poets--the celebrated earl of ,surrey1 ,sir ,philip ,sidney and his sister the countess of ,pembroke1 ,george ,sandys1 ,george ,wither1 ,john ,milton and ,john ,keble4 ,in their versions1 as might be expected1 there are occasional gleams of power and beauty1 exceeding anything to be found in ,sternhold and ,hopkins1 or ,tate and ,brady2 but even in the best these are rare1 and chiefly occur where the strict idea of translation has been most widely departed from4 ,in all of them1 as a rule1 the life and spirit1 which in prose versions of the psalms are so wonderfully preserved1 have disappeared4 ,the conclusion practically suggested by so many failures is that the difficulties of metrical translation1 always great1 are in this case insuperable2 and that1 while the psalms like other parts of scripture are abundantly suggestive of motive and material for hymnographers1 it is by assimilation and adaptation1 and not by any attempt to transform their exact sense into modern poetry1 that they may be best used for this purpose4 ,the order in council of #agjc is the latest act of any public authority by which an express sanction has been given to the use of psalms or hymns in the ,church of ,england4 ,at the end1 indeed1 of many ,prayer-books1 till about the middle of the #aith century1 there were commonly found1 besides some of the hymns sanctioned by that order in council1 or of those contained in the book of #aefb1 a sacramental and a ,christmas hymn by ,doddridge2 a ,christmas hymn 7varied by ,martin ,madan7 from ,charles ,wesley2 an ,easter hymn of the #ahth century1 beginning ,jesus ,christ has risen to-day2 and abridgments ,bishop ,ken's ,morning and ,evening ,hymns4 ,these additions first began to be made in or about #agia1 in ,london editions of the ,prayer-book and ,psalter1 at the mere will and pleasure 7so far as appears7 of the printers4 ,they had no sort of authority4 ,english congregational hymnody4 ,in the state of authority1 opinion and practice disclosed by the preceding narrative may be found the true explanation of the fact that1 in the country of ,chaucer1 ,spenser1 ,shakespeare and ,milton1 and notwithstanding the example of ,germany1 no native congregational hymnody worthy of the name arose till after the commencement of the #ahth century4 ,yet there was no want of appreciation of the power and value of congregational church music4 ,milton could write1 before #afde3-- ,there let the pealing organ blow ,to the full-voiced quire below ,in service high1 and anthems clear1 ,as may with sweetness through mine ear ,dissolve me into ecstasies1 ,and bring all ,heaven before mine eyes4 ,thomas ,mace1 in his ,music's ,monument 7#afgf71 thus described the effect of psalm-singing before sermons by the congregation in ,york ,minster on ,sundays1 during the siege of #afdd3 ,when that vast concording unity of the whole congregational chorus came thundering in1 even so as it made the very ground shake under us1 oh1 the unutterable ravishing soul's delight6 in the which ,i was so transported and wrapt up in high contemplations that there was no room left in my whole man1 body1 soul and spirit1 for anything below divine and heavenly raptures2 nor could there possibly be anything to which that very singing might be truly compared1 except the right apprehension or conceiving of that glorious and miraculous quire1 recorded in the scriptures at the dedication of the temple4 ,nor was there any want of men well qualified1 and by the turn of their minds predisposed1 to shine in this branch of literature4 ,some 7like ,sandys1 ,boyd and ,barton7 devoted themselves altogether to paraphrases of other scriptures as well as the psalms4 ,others 7like ,george ,herbert1 and ,francis and ,john ,quarles7 moralized1 meditated1 soliloquized and allegorized in verse4 ,without reckoning these1 there were a few1 even before the ,restoration1 who came very near to the ideal of hymnody4 ,wedderburn4 ,first in time is the ,scottish poet ,john ,wedderburn1 who translated several of ,luther's hymns1 and in his ,compendious ,book of ,godly and ,spiritual ,songs added others of his own 7or his brothers'7 composition4 ,some of these poems1 published before #aefj1 are of uncommon excellence1 uniting ease and melody of rhythm1 and structural skill1 with grace of expression1 and simplicity1 warmth and reality of religious feeling4 ,those entitled ,give me thy heart1 ,go1 heart1 and ,leave me not1 which will be found in a collection of #ahfj called ,sacred ,songs of ,scotland1 require little1 beyond the change of some archaisms of language1 to adapt them for church or domestic use at the present day4 ,dickson4 ,next come the two hymns of ,the new ,jerusalem1 by an ,english ,roman ,catholic priest signing himself ,f4 ,b4 ,p4 7supposed to be ,francis ,baker1 ,presbyter71 and by another ,scottish poet1 ,david ,dickson1 of which the history is given by ,dr ,bonar in his edition of ,dickson's work4 ,this 7,dickson's71 which begins ,o mother dear1 ,jerusalem1 and has long been popular in ,scotland1 is a variation and amplification by the addition of a large number of new stanzas of the ,english original1 beginning ,jerusalem1 my happy home1 written in ,queen ,elizabeth's time1 and printed 7as appears by a copy in the ,british ,museum7 about #afaf1 when ,dickson was still young4 ,both have an easy natural flow1 and a simple happy rendering of the beautiful scriptural imagery upon the subject1 with a spirit of primitive devotion uncorrupted by medieval peculiarities4 ,the ,english hymn of which some stanzas are now often sung in churches is the true parent of the several shorter forms1--all of more than common merit1--which1 in modern hymn-books1 begin with the same first line1 but afterwards deviate from the original4 ,kindred to these is the very fine and faithful translation1 by ,dickson's contemporary ,drummond of ,hawthornden of the ancient ,urbs beata ,hierusalem 7,jerusalem1 that place divine74 ,other ancient hymns 7two of ,thomas ,aquinas1 and the ,dies ,irae7 were also well translated1 in #afdf1 by ,richard ,crashaw1 after he had become a ,roman ,catholic and had been deprived by the parliament of his fellowship at ,cambridge4 ,wither4 ,conspicuous among the sacred poets of the first two ,stuart reigns in ,england was ,george ,wither4 ,his ,hymnes and ,songs of the ,church appeared in #afbb-afbc1 under a patent of ,king ,james ,i41 by which they were declared worthy and profitable to be inserted1 in convenient manner and due place1 into every ,english ,psalm-book to metre4 ,his ,hallelujah 7in which some of the former ,hymnes and ,songs were repeated7 followed in #afda4 ,some of the ,hymnes and ,songs were set to music by ,orlando ,gibbons1 and those in both books were written to be sung1 though there is no evidence that the author contemplated the use of any of them in churches4 ,they included hymns for every day in the week 7founded1 as those contributed nearly a century afterwards by ,charles ,coffin to the ,parisian ,breviary also were1 upon the successive works of the days of creation72 hymns for all the church seasons and festivals1 including saints' days2 hymns for various public occasions2 and hymns of prayer1 meditation and instruction1 for all sorts and conditions of men1 under a great variety of circumstances--being at once a ,christian ,year and a manual of practical piety4 ,many of them rise to a very high point of excellence1--particularly the general invitation to praise ,god 7,come1 ,o come1 in pious lays71 with which ,hallelujah opens2 the thanksgivings for peace and for victory1 the ,coronation ,hymn1 a ,christmas1 an ,epiphany1 and an ,easter ,hymn1 and one for ,st ,bartholomew's day 7,hymns #a1 #gd1 #ge1 and #hd in part i41 and #bf1 #bi1 #cf and #ed in part ii4 of ,hallelujah74 ,cosin4 ,john ,cosin1 afterwards bishop of ,durham1 published in #afbg a volume of ,private ,devotions1 for the canonical hours and other occasions4 ,in this there are seven or eight hymns of considerable merit1--among them a very good version of the ,ambrosian ,jam lucis orto sidere1 and the shorter version of the ,veni ,creator1 which was introduced after the ,restoration into the consecration and ordination services of the ,church of ,england4 ,milton4 ,the hymns of ,milton 7on the ,nativity1 ,passion1 ,circumcision and at a ,solemn ,music71 written about #afbi1 in his early manhood1 were probably not intended for singing2 but they are odes full of characteristic beauty and power4 ,jeremy ,taylor4 ,during the ,commonwealth1 in #afed1 ,jeremy ,taylor published at the end of his ,golden ,grove1 twenty-one hymns1 described by himself as celebrating the mysteries and chief festivals of the year1 according to the manner of the ancient church1 fitted to the fancy and devotion of the younger and pious persons1 apt for memory1 and to be joined1 to their other prayers4 ,of these1 his accomplished editor1 ,bishop ,heber1 justly says3-- ,they are in themselves1 and on their own account1 very interesting compositions4 ,their metre1 indeed1 which is that species of spurious ,pindaric which was fashionable with his contemporaries1 is an obstacle1 and must always have been one1 to their introduction into public or private psalmody2 and the mixture of that alloy of conceits and quibbles which was an equally frequent and still greater defilement of some of the finest poetry of the #agth century will materially diminish their effect as devotional or descriptive odes4 ,yet1 with all these faults1 they are powerful1 affecting1 and often harmonious2 there are many passages of which ,cowley need not have been ashamed1 and some which remind us1 not disadvantageously1 of the corresponding productions of ,milton4 ,he mentions particularly the advent hymn 7,lord1 come away71 part of the hymn ,on heaven1 and 7as more regular in metre1 and in words more applicable to public devotion7 the ,prayer for ,charity 7,full of mercy1 full of love74 ,restoration period4 ,the epoch of the ,restoration produced in #affd ,samuel ,crossman's ,young ,man's ,calling1 with a few ,divine ,meditations in verse attached to it2 in #affh ,john ,austin's ,devotions in the ancient way of offices1 with psalms1 hymns and prayers for every day in the week and every holyday in the year2 and in #afha ,richard ,baxter's ,poetical ,fragments4 ,in these books there are altogether seven or eight hymns1 the whole or parts of which are extremely good3 ,crossman's ,new ,jerusalem 7,sweet place1 sweet place alone71 one of the best of that class1 and ,my life's a shade1 my days2 ,austin's ,hark1 my soul1 how everything1 ,fain would my thoughts fly up to ,thee1 ,lord1 now the time returns1 ,wake all my hopes1 lift up your eyes2 and ,baxter's ,my whole1 though broken heart1 ,o ,lord1 and ,ye holy angels bright4 ,austin's ,offices 7he was a ,roman ,catholic7 seem to have attracted much attention4 ,theophilus ,dorrington1 in #afhf1 published variations of them under the title of ,reformed ,devotions2 ,george ,hickes1 the non-juror1 wrote one of his numerous recommendatory prefaces to ,s4 ,hopton's edition2 and the ,wesleys1 in their earliest hymn-book1 adopted hymns from them1 with little alteration4 ,these writers were followed by ,john ,mason in #afhc1 and ,thomas ,shepherd in #afib1--the former1 a country clergyman1 much esteemed by ,baxter and other ,nonconformists2 the latter himself a ,nonconformist1 who finally emigrated to ,america4 ,between these two men there was a close alliance1 ,shepherd's ,penitential ,cries being published as an addition to the ,spiritual ,songs of ,mason4 ,their hymns came into early use in several ,nonconformist congregations2 but1 with the exception of one by ,mason 7,there is a stream which issues forth71 they are not suitable for public singing4 ,in those of ,mason there is often a very fine vein of poetry2 and later authors have1 by extracts or centoes from different parts of his works 7where they were not disfigured by his general quaintness71 constructed several hymns of more than average excellence4 ,three other eminent names of the #agth century remain to be mentioned1 ,john ,dryden1 ,bishop ,ken and ,bishop ,simon ,patrick2 with which may be associated that of ,addison1 though he wrote in the #ahth century4 ,dryden1 ,ken4 ,patrick ,addison4 ,dryden's translation of ,veni ,creator a cold and laboured performance1 is to be met with in many hymn-books4 ,abridgments of ,ken's morning and evening hymns are in all4 ,these1 with the midnight hymn1 which is not inferior to them1 first appeared ,in #afig1 appended to the third edition of the author's ,manual of ,prayers for ,winchester ,scholars4 ,between these and a large number of other hymns 7on the attributes of ,god1 and for the festivals of the church7 published by ,bishop ,ken after #agjc the contrast is remarkable4 ,the universal acceptance of the morning and evening hymns is due to their transparent simplicity1 warm but not overstrained devotion1 and extremely popular style4 ,those afterwards published have no such qualities4 ,they are mystical1 florid1 stiff1 didactic and seldom poetical1 and deserve the neglect into which they have fallen4 ,bishop ,patrick's hymns were chiefly translations from the ,latin1 most of them from ,prudentius4 ,the best is a version of ,alleluia dulce carmen4 ,of the five attributed to ,addison1 not more than three are adapted to public singing2 one 7,the spacious firmament on high7 is a very perfect and finished composition1 taking rank among the best hymns in the ,english language4#c ,from the preface to ,simon ,browne's hymns1 published in #agbj1 we learn that down to the time of ,dr ,watts the only hymns known to be in common use1 either in private families or in ,christian assemblies1 were those of ,barton1 ,mason and ,shepherd1 together with an attempt to turn some of ,george ,herbert's poems into common metre1 and a few sacramental hymns by authors now forgotten1 named ,joseph ,boyse 7#affj-agbh7 and ,joseph ,stennett4 ,of the #adaj authors of original ,british hymns enumerated in ,daniel ,sedgwick's catalogue1 published in #ahfc1 #abac are of later date than #agjg2 and1 if any correct enumeration could be made of the total number of hymns of all kinds published in ,great ,britain before and after that date1 the proportion subsequent to #agjg would be very much larger4 ,the ,english ,independents1 as represented by ,dr ,isaac ,watts1 have a just claim to be considered the real founders of modern ,english hymnody4 ,watts was the first to understand the nature of the want1 and1 by the publication of his ,hymns in #agjg-agji1 and ,psalms 7not translations1 but hymns founded on psalms7 in #agji1 he led the way in providing for it4 ,his immediate followers were ,simon ,browne and ,philip ,doddridge4 ,later in the #ahth century1 ,joseph ,hart1 ,thomas ,gibbons1 ,miss ,anne ,steele1 ,samuel ,medley1 ,samuel ,stennett1 ,john ,ryland1 ,benjamin ,beddome and ,joseph ,swain succeeded to them4 ,watts4 ,among these writers1 most of whom produced some hymns of merit1 and several are extremely voluminous1 ,isaac ,watts and ,philip ,doddridge are pre-eminent4 ,it has been the fashion with some to disparage ,watts1 as if he had never risen above the level of his ,hymns for ,little ,children4 ,no doubt his taste is often faulty1 and his style very unequal1 but1 looking to the good1 and disregarding the large quantity of inferior matter1 it is probable that more hymns which approach to a very high standard of excellence1 and are at the same time suitable for congregational use1 may be found in his works than in those of any other ,english writer4 ,such are ,when ,i survey the wondrous cross1 ,jesus shall reign where'er the sun 7and also another adaptation of the same #gbnd ,psalm71 ,before ,jehovah's awful throne 7first line of which1 however1 is not his1 but ,wesley's71 ,joy to the world1 the ,lord is come1 ,my soul1 repeat ,his praise1 ,why do we mourn departing friends1 ,there is a land of pure delight1 ,our ,god1 our help in ages past1 ,up to the hills ,i lift mine eyes1 and many more4 ,it is true that in some of these cases dross is found in the original poems mixed with gold2 but the process of separation1 by selection without change1 is not difficult4 ,as long as pure nervous ,english1 unaffected fervour1 strong simplicity and liquid yet manly sweetness are admitted to be characteristics of a good hymn1 works such as these must command admiration4 ,doddridge4 ,doddridge is1 generally1 much more laboured and artificial2 but his place also as a hymn-writer ought to be determined1 not by his failures1 but by his successes1 of which the number is not inconsiderable4 ,in his better works he is distinguished by a graceful and pointed1 sometimes even a noble style4 ,his ,hark1 the glad sound1 the ,saviour comes 7which is1 indeed1 his masterpiece71 is as sweet1 vigorous and perfect a composition as can anywhere be found4 ,two other hymns1 ,how gentle ,god's commands1 and that which1 in a form slightly varied1 became the ,o ,god of ,bethel1 by whose hand1 of the ,scottish ,paraphrases1 well represent his softer manner4 ,of the other followers in the school of ,watts1 ,miss ,anne ,steele 7#agag-aggh7 is the most popular and perhaps the best4 ,her hymn beginning ,far from these narrow scenes of night deserves high praise1 even by the side of other good performances on the same subject4 ,the influence of ,watts was felt in ,scotland1 and among the first whom it reached there was ,ralph ,erskine4 ,this seems to have been after the publication of ,erskine's ,gospel ,sonnets1 which appeared in #agcb1 five years before he joined his brother ,ebenezer in the ,secession ,church4 ,the ,gospel ,sonnets became1 as some have said1 a people's classic2 but there is in them very little which belongs to the category of hymnody4 ,more than nineteen-twentieths of this very curious book are occupied with what are1 in fact1 theological treatises and catechisms1 mystical meditations on ,christ as a bridegroom or husband1 and spiritual enigmas1 paradoxes1 and antithetical conceits1 versified1 it is true1 but of a quality of which such lines as-- ,faith's certain by fiducial arts1 ,sense by its evidential facts1 may be taken as a sample4 ,the grains of poetry scattered through this large mass of ,calvinistic divinity are very few2 yet in one short passage of seven stanzas 7,o send me down a draught of love71 the fire burns with a brightness so remarkable as to justify a strong feeling of regret that the gift which this writer evidently had in him was not more often cultivated4 ,another passage1 not so well sustained1 but of considerable beauty 7part of the last piece under the title ,the believer's soliloquy71 became afterwards1 in the hands of ,john ,berridge1 the foundation of a very striking hymn 7,o happy saints1 who walk in light74 ,after his secession1 ,ralph ,erskine published two paraphrases of the ,song of ,solomon1 and a number of other ,scripture songs1 paraphrased1 in like manner1 from the ,old and ,new ,testaments4 ,in these the influence of ,watts became very apparent1 not only by a change in the writer's general style1 but by the direct appropriation of no small quantity of matter from ,dr ,watts's hymns1 with variations which were not always improvements4 ,his paraphrases of ,i ,cor4 i4 #bd2 ,gal4 vi4 #ad2 ,heb4 vi4 #ag-ai2 ,rev4 v4 #aa1 #ab1 vii4 #aj-ag1 and xii4 #g-ab are little else than ,watts transformed4 ,one of these 7,rev4 vii4 #aj-ag7 is interesting as a variation and improvement1 intermediate between the original and the form which it ultimately assumed as the #ffth ,paraphrase of the ,church of ,scotland1 of ,watts's ,what happy men or angels these1 and ,these glorious minds1 how bright they shine4 ,no one can compare it with its ultimate product1 ,how bright these glorious spirits shine1 without perceiving that ,william ,cameron followed ,erskine1 and only added finish and grace to his work1--both excelling ,watts1 in this instance1 in simplicity as well as in conciseness4 ,scottish paraphrases4 ,of the contributions to the authorized ,paraphrases 7with the settlement of which committees of the ,general ,assembly of the ,church of ,scotland were occupied from #agde1 or earlier1 till #agha71 the most noteworthy1 besides the two already mentioned1 were those of ,john ,morrison and those claimed for ,michael ,bruce4 ,the obligations of these ,paraphrases to ,english hymnody1 already traced in some instances 7to which may be added the adoption from ,addison of three out of the five hymns appended to them71 are perceptible in the vividness and force with which these writers1 while adhering with a severe simplicity to the sense of the passages of ,scripture which they undertook to render1 fulfilled the conception of a good original hymn4 ,morrison's ,the race that long in darkness pined and ,come1 let us to the ,lord our ,god1 and ,bruce's ,where high the heavenly temple stands 7if this was really his71 are well entitled to that praise4 ,the advocates of ,bruce in the controversy1 not yet closed1 as to the poems said to have been entrusted by him to ,john ,logan1 and published by ,logan in his own name1 also claim for him the credit of having varied the paraphrase ,behold1 the mountain of the ,lord1 from its original form1 as printed by the committee of the ,general ,assembly in #agde1 by some excellent touches4 ,methodist hymns4 ,attention must now be directed to the hymns produced by the ,methodist movement1 which began about #agch1 and which afterwards became divided1 between those esteemed ,arminian1 under ,john ,wesley1 those who adhered to the ,moravians1 when the original alliance between that body and the founders of ,methodism was dissolved1 and the ,calvinists1 of whom ,whitfield was the leader1 and ,selina1 countess of ,huntingdon1 the patroness4 ,each of these sections had its own hymn-writers1 some of whom did1 and others did not1 secede from the ,church of ,england4 ,the ,wesleyans had ,charles ,wesley1 ,robert ,seagrave and ,thomas ,olivers2 the ,moravians1 ,john ,cennick1 with whom1 perhaps1 may be classed ,john ,byrom1 who imbibed the mystical ideas of some of the ,german schools2 the ,calvinists1 ,augustus ,montague ,toplady1 ,john ,berridge1 ,william ,williams1 ,martin ,madan1 ,thomas ,haweis1 ,rowland ,hill1 ,john ,newton and ,william ,cowper4 ,charles ,wesley4 ,among all these writers1 the palm undoubtedly belongs to ,charles ,wesley4 ,in the first volume of hymns published by the two brothers are several good translations from the ,german1 believed to be by ,john ,wesley1 who1 although he translated and adapted1 is not supposed to have written any original hymns2 and the influence of ,german hymnody1 particularly of the works of ,paul ,gerhardt1 ,scheffler1 ,tersteegen and ,zinzendorf1 may be traced in a large proportion of ,charles ,wesley's works4 ,he is more subjective and meditative than ,watts and his school2 there is a didactic turn1 even in his most objective pieces1 as1 for example1 in his ,christmas and ,easter hymns2 most of his works are supplicatory1 and his faults are connected with the same habit of mind4 ,he is apt to repeat the same thoughts1 and to lose force by redundancy--he runs sometimes even to a tedious length2 his hymns are not always symmetrically constructed1 or well balanced and finished off4 ,but he has great truth1 depth and variety of feeling2 his diction is manly and always to the point2 never florid1 though sometimes passionate and not free from exaggeration2 often vivid and picturesque4 ,of his spirited style there are few better examples than ,o for a thousand tongues to sing1 ,blow ye the trumpet1 blow1 ,rejoice1 the ,lord is ,king and ,come1 let us join our friends above2 of his more tender vein1 ,happy soul1 thy days are ended2 and of his fervid contemplative style 7without going beyond hymns fit for general use71 ,o ,thou who earnest from above1 ,forth in ,thy name1 ,o ,lord1 ,i go and ,eternal beam of light divine4 ,with those whose taste is for hymns in which warm religious feelings are warmly and demonstratively expressed1 ,jesus1 lover of my soul1 is as popular as any of these4 ,olivers4 ,of the other ,wesleyan hymn-writers1 ,olivers1 originally a ,welsh shoemaker and afterwards a preacher1 is the most remarkable4 ,he is the author of only two works1 both odes1 in a stately metre1 and from their length unfit for congregational singing1 but one of them1 ,the ,god of ,abraham praise1 an ode of singular power and beauty4 ,cennick1 ,hammond1 ,byrom4 ,the ,moravian ,methodists produced few hymns now available for general use4 ,the best are ,cennick's ,children of the heavenly ,king and ,hammond's ,awake and sing the song of ,moses and the ,lamb1 the former of which 7abridged71 and the latter as varied by ,madan1 are found in many hymn-books1 and are deservedly esteemed4 ,john ,byrom1 whose name we have thought it convenient to connect with these1 though he did not belong to the ,moravian community1 was the author of a ,christmas hymn 7,christians awake1 salute the happy morn7 which enjoys great popularity2 and also of a short subjective hymn1 very fine both in feeling and in expression1 ,my spirit longeth for ,thee within my troubled breast4 ,toplady4 ,the contributions of the ,calvinistic ,methodists to ,english hymnody are of greater extent and value4 ,few writers of hymns had higher gifts than ,toplady1 author of ,rock of ages1 by some esteemed the finest in the ,english language4 ,he was a man of ardent temperament1 enthusiastic zeal1 strong convictions and great energy of character4 ,he had1 says one of his biographers1 the courage of a lion1 but his frame was brittle as glass4 ,between him and ,john ,wesley there was a violent opposition of opinion1 and much acrimonious controversy2 but the same fervour and zeal which made him an intemperate theologian gave warmth1 richness and spirituality to his hymns4 ,in some of them1 particularly those which1 like ,deathless principle1 arise1 are meditations after the ,german manner1 and not without direct obligation to ,german originals1 the setting is somewhat too artificial2 but his art is never inconsistent with a genuine flow of real feeling4 ,others 7e4g4 ,when languor and disease invade and ,your harps1 ye trembling saints7 fail to sustain to the end the beauty with which they began1 and would have been better for abridgment4 ,but in all these1 and in most of his other works1 there is great force and sweetness1 both of thought and language1 and an easy and harmonious versification4 ,berridge1 ,williams and ,r4 ,hill4 ,berridge1 ,william ,williams 7#agag-agia7 and ,rowland ,hill1 all men remarkable for eccentricity1 activity and the devotion of their lives to the special work of missionary preaching1 though not the authors of many good hymns1 composed1 or adapted from earlier compositions1 some of great merit4 ,one of ,berridge1 adapted from ,erskine1 has been already mentioned2 another1 adapted from ,watts1 is ,jesus1 cast a look on me4 ,williams1 a ,welshman1 who wrote ,guide me1 ,o ,thou great ,jehovah1 was especially an apostle of ,calvinistic ,methodism in his own country1 and his hymns are still much used in the principality4 ,rowland ,hill wrote the popular hymn beginning ,exalted high at ,god's right hand4 ,cowper and ,newton4 ,if1 however1 the number as well as the quality of good hymns available for general use is to be regarded1 the authors of the ,olney ,hymns are entitled to be placed at the head of all the writers of this ,calvinistic school4 ,the greater number of the ,olney ,hymns are1 no doubt1 homely and didactic2 but to the best of them1 and they are no inconsiderable proportion1 the tenderness of ,cowper and the manliness of ,john ,newton 7#agbe-ahjg7 give the interest of contrast1 as well as that of sustained reality4 ,if ,newton carried to some excess the sound principle laid down by him1 that perspicuity1 simplicity and ease should be chiefly attended to1 and the imagery and colouring of poetry1 if admitted at all1 should be indulged very sparingly and with great judgment1 if he is often dry and colloquial1 he rises at other times into soul-animating strains1 such as ,glorious things of thee are spoken1 ,zion1 city of our ,god2 and sometimes 7as in ,approach1 my soul1 the mercy seat7 rivals ,cowper himself in depth of feeling4 ,cowper's hymns in this book are1 almost without exception1 worthy of his name4 ,among them are ,hark1 my soul1 it is the ,lord1 ,there is a fountain filled with blood1 ,far from the world1 ,o ,lord1 ,i flee1 ,god moves in a mysterious way and ,sometimes a light surprises4 ,some1 perhaps1 even of these1 and others of equal excellence 7such as ,o for a closer walk with ,god71 speak the language of a special experience1 which1 in ,cowper's case1 was only too real1 but which could not1 without a degree of unreality not desirable in exercises of public worship1 be applied to themselves by all ordinary ,christians4 #aith-century hymns4 ,r4 ,grant4 ,bowdler4 ,during the first quarter of the #aith century there were not many indications of the tendency1 which afterwards became manifest1 to enlarge the boundaries of ,british hymnody4 ,the ,remains of ,henry ,kirke ,white1 published by ,southey in #ahjg1 contained a series of hymns1 some of which are still in use2 and a few of ,bishop ,heber's hymns and those of ,sir ,robert ,grant1 which1 though offending rather too much against ,john ,newton's canon1 are well known and popular1 appeared between #ahaa and #ahaf1 in the ,christian ,observer4 ,in ,john ,bowdler's ,remains1 published soon after his death in #ahae1 there are a few more of the same1 perhaps too scholarlike1 character4 ,but the chief hymn-writers of that period were two clergymen of the ,established ,church--one in ,ireland1 ,thomas ,kelly1 and the other in ,england1 ,william ,hurn--who both became ,nonconformists1 and the ,moravian poet1 ,james ,montgomery 7#agga-ahed71 a native of ,scotland4 ,kelly4 ,kelly was the son of an ,irish judge1 and in #ahjd published a small volume of ninety-six hymns1 which grew in successive editions till1 in the last before his death in #ahed1 they amounted to #gfe4 ,there is1 as might be expected1 in this great number a large preponderance of the didactic and commonplace4 ,but not a few very excellent hymns may be gathered from them4 ,simple and natural1 without the vivacity and terseness of ,watts or the severity of ,newton1 ,kelly has some points in common with both those writers1 and he is less subjective than most of the ,methodist school4 ,his hymns beginning ,lo6 ,he comes1 let all adore ,him1 and ,through the day ,thy love hath spared us1 have a rich1 melodious movement2 and another1 ,we sing the praise of ,him who died1 is distinguished by a calm1 subdued power1 rising gradually from a rather low to a very high key4 ,hurn4 ,hurn published in #ahac a volume of #cgj hymns1 which were afterwards increased to #dbj4 ,there is little in them which deserves to be saved from oblivion2 but one at least1 ,there is a river deep and broad1 may bear comparison with the best of those which have been produced upon the same1 and it is rather a favourite1 theme4 ,montgomery4 ,the ,psalms and ,hymns of ,james ,montgomery were published in #ahbb and #ahbe1 though written earlier4 ,more cultivated and artistic than ,kelly1 he is less simple and natural4 ,his ,hail to the ,lord's ,anointed1 ,songs of praise the angels sang and ,mercy alone can meet my case are among his most successful efforts4 ,collections of hymns4 ,during this period1 the collections of miscellaneous hymns for congregational use1 of which the example was set by the ,wesleys1 ,whitfield1 ,toplady and ,lady ,huntingdon1 had greatly multiplied2 and with them the practice 7for which1 indeed1 too many precedents existed in the history of ,latin and ,german hymnody7 of every collector altering the compositions of other men without scruple1 to suit his own doctrine or taste2 with the effect1 too generally1 of patching and disfiguring1 spoiling and emasculating the works so altered1 substituting neutral tints for natural colouring1 and a dead for a living sense4 ,in the ,church of ,england the use of these collections had become frequent in churches and chapels1 principally in cities and towns1 where the sentiments of the clergy approximated to those of the ,nonconformists4 ,in rural parishes1 when the clergy were not of the ,evangelical school1 they were generally held in disfavour2 for which1 even if doctrinal prepossessions had not entered into the question1 the great want of taste and judgment often manifested in their compilation1 and perhaps also the prevailing mediocrity of the bulk of the original compositions from which most of them were derived1 would be enough to account4 ,in addition to this1 the idea that no hymns ought to be used in any services of the ,church of ,england1 except prose anthems after the third collect1 without express royal or ecclesiastical authority1 continued down to that time largely to prevail among high churchmen4 ,heber1 ,milman1 ,keble4 ,mant4 ,newman4 ,two publications1 which appeared almost simultaneously in #ahbg--;,bishop ,heber's ,hymns1 with a few added by ,dean ,milman1 and ,john ,keble's ,christian ,year 7not a hymn-book1 but one from which several admirable hymns have been taken1 and the well-spring of many streams of thought and feeling by which good hymns have since been produced7--introduced a new epoch1 breaking down the barrier as to hymnody which had till then existed between the different theological schools of the ,church of ,england4 ,in this movement ,richard ,mant1 bishop of ,down1 was also one of the first to co-operate4 ,it soon received a great additional impulse from the increased attention which1 about the same time1 began to be paid to ancient hymnody1 and from the publication in #ahcc of ,bunsen's ,gesangbuch4 ,among its earliest fruits was the ,lyra apostolica1 containing hymns1 sonnets and other devotional poems1 most of them originally contributed by some of the leading authors of the ,tracts for the ,times to the ,british ,magazine2 the finest of which is the pathetic ,lead1 kindly ,light1 amid th' encircling gloom1 by ,cardinal ,newman--well known1 and universally admired4 ,from that time hymns and hymn-writers rapidly multiplied in the ,church of ,england1 and in ,scotland also4 ,nearly #fjj authors whose publications were later than #ahbg are enumerated in ,sedgwick's catalogue of #ahfc1 and about half a million hymns are now in existence4 ,works1 critical and historical1 upon the subject of hymns1 have also multiplied2 and collections for church use have become innumerable--several of the various religious denominations1 and many of the leading ecclesiastical and religious societies1 having issued hymn-books of their own1 in addition to those compiled for particular dioceses1 churches and chapels1 and to books 7like ,hymns ,ancient and ,modern1 published #ahfa1 supplemented #ahhi1 revised edition1 #aije7 which have become popular without any sanction from authority4 ,to mention all the authors of good hymns since the commencement of this new epoch would be impossible2 but probably no names could be chosen more fairly representative of its characteristic merits1 and perhaps also of some of its defects1 than those of ,josiah ,conder and ,james ,edmeston among ,english ,nonconformists2 ,henry ,francis ,lyte and ,charlotte ,elliott among evangelicals in the ,church of ,england2 ,john ,mason ,neale and ,christopher ,wordsworth1 bishop of ,lincoln1 among ,english churchmen of the higher school2 ,arthur ,penrhyn ,stanley1 ,edward ,h4 ,plumptre1 ,frances ,ridley ,havergal2 and in ,scotland1 ,dr ,horatius ,bonar1 ,dr ,norman ,macleod and ,dr ,george ,matheson4 ,american hymn-writers belong to the same schools1 and have been affected by the same influences4 ,some of them have enjoyed a just reputation on both sides of the ,atlantic4 ,among those best known are ,john ,greenleaf ,whittier1 ,bishop ,doane1 ,dr ,w4 ,a4 ,muhlenberg and ,thomas ,hastings2 and it is difficult to praise too highly such works as the ,christmas hymn1 ,it came upon the midnight clear1 by ,edmund ,h4 ,sears2 the ,ascension hymn1 ,thou1 who didst stoop below1 by ,mrs ,s4 ,e4 ,miles2 two by ,dr ,ray ,palmer1 ,my faith looks up to ,thee1 ,thou ,lamb of ,calvary1 and ,jesus1 ,thou joy of loving hearts1 the latter of which is the best among several good ,english versions of ,jesu1 dulcedo1 cordium2 and ,lord of all being1 throned afar1 by ,oliver ,wendell ,holmes4 ,the more modern ,moody and ,sankey hymns 7see ,moody1 ,d4 ,l47 popularized a new ,evangelical type1 and the ,salvation ,army has carried this still farther4 #g4 ,conclusion4--,the object aimed at in this article has been to trace the general history of the principal schools of ancient and modern hymnody1 and especially the history of its use in the ,christian church4 ,for this purpose it has not been thought necessary to give any account of the hymns of ,racine1 ,madame ,guyon and others1 who can hardly be classed with any school1 nor of the works of ,caesar ,malan of ,geneva 7#aghg-ahfd7 and other quite modern hymn-writers of the ,reformed churches in ,switzerland and ,france4 ,on a general view of the whole subject1 hymnody is seen to have been a not inconsiderable factor in religious worship4 ,it has been sometimes employed to disseminate and popularize particular views1 but its spirit and influence has been1 on the whole1 catholic4 ,it has embodied the faith1 trust and hope1 and no small part of the inward experience1 of generation after generation of men1 in many different countries and climates1 of many different nations1 and in many varieties of circumstances and condition4 ,coloured1 indeed1 by these differences1 and also by the various modes in which the same truths have been apprehended by different minds and sometimes reflecting partial and imperfect conceptions of them1 and errors with which they have been associated in particular churches1 times and places1 its testimony is1 nevertheless1 generally the same4 ,it has upon it a stamp of genuineness which cannot be mistaken4 ,it bears witness to the force of a central attraction more powerful than all causes of difference1 which binds together times ancient and modern1 nations of various race and language1 churchmen and nonconformists1 churches reformed and unreformed2 to a true fundamental unity among good ,christians2 and to a substantial identity in their moral and spiritual experience4 7,s47 ,the regular practice of hymnody in ,english musical history dates from the beginning of the #afth century4 ,luther's verses were adapted sometimes to ancient church melodies1 sometimes to tunes of secular songs1 and sometimes had music composed for them by himself and others4 ,many rhyming ,latin hymns are of earlier date whose tunes are identified with them1 some of which tunes1 with the subject of their ,latin text1 are among the ,reformer's appropriations2 but it was he who put the words of praise and prayer into the popular mouth1 associated with rhythmical music which aided to imprint the words upon the memory and to enforce their enunciation4 ,in conjunction with his friend ,johann ,walther1 ,luther issued a collection of poems for choral singing in #aebd1 which was followed by many others in ,north ,germany4 ,the ,english versions of the ,psalms by ,sternhold and ,hopkins and their predecessors1 and the ,french version by ,clement ,marot and ,theodore ,beza1 were written with the same purpose of fitting sacred minstrelsy to the voice of the multitude4 ,goudimel in #aeff and ,claudin le ,jeune in #afjg printed harmonizations of tunes that had then become standard for the ,psalms1 and in ,england several such publications appeared1 culminating in ,thomas ,ravenscroft's famous collection1 ,the ,whole ,book of ,psalms 7#afba72 in all of these the arrangements of the tunes were by various masters4 ,the ,english practice of hymn-singing was much strengthened on the return of the exiled reformers from ,frankfort and ,geneva1 when it became so general that1 according to ,bishop ,jewell1 thousands of the populace who assembled at ,paul's ,cross to hear the preaching would join in the singing of psalms before and after the sermon4 ,the placing of the choral song of the church within the lips of the people had great religious and moral influence2 it has had also its great effect upon art1 shown in the productions of the ,north ,german musicians ever since the first days of the ,reformation1 which abound in exercises of scholarship and imagination wrought upon the tunes of established acceptance4 ,some of these are accompaniments to the tunes with interludes between the several strains1 and some are compositions for the organ or for orchestral instruments that consist of such elaboration of the themes as is displayed in accompaniments to voices1 but of far more complicated and extended character4 ,a special art-form that was developed to a very high degree1 but has passed into comparative disuse1 was the structure of all varieties of counterpoint extemporaneously upon the known hymn-tunes 7chorals71 and several masters acquired great fame by success in its practice1 of whom ,j4 ,a4 ,reinken 7#afbc-agbb71 ,johann ,pachelbel 7#afec-agjf71 ,georg ,boehm and the great ,j4 ,s4 ,bach are specially memorable4 ,the hymnody of ,north ,germany has for artistic treatment a strong advantage which is unpossessed by that of ,england1 in that for the most part the same verses are associated with the same tunes1 so that1 whenever the text or the music is heard1 either prompts recollection of the other1 whereas in ,england tunes were always and are now often composed to metres and not to poems2 any tune in a given metre is available for every poem in the same1 and hence there are various tunes to one poem1 and various poems to one tune4#d ,in ,england a tune is named generally after some place--as ,york1 ,windsor1 ,dundee1--or by some other unsignifying word2 in ,north ,germany a tune is mostly named by the initial words of the verses to which it is allied1 and consequently1 whenever it is heard1 whether with words or without1 it necessarily suggests to the hearer the whole subject of that hymn of which it is the musical moiety undivorceable from the literary half4 ,manifold as they are1 knowledge of the choral tunes is included in the earliest schooling of every ,lutheran and every ,calvinist in ,germany1 which thus enables all to take part in performance of the tunes1 and hence expressly the definition of choral4 ,compositions grounded on the standard tune are then not merely school exercises1 but works of art which link the sympathies of the writer and the listener1 and aim at expressing the feeling prompted by the hymn under treatment4 ,,bibliography3 ,i4 ,ancient4--,george ,cassander1 ,hymni ecclesiastici 7,cologne1 #aeef72 ,georgius ,fabricius1 ,potarum veterum ecclesiasticorum 7,frankfort1 #aegh72 ,cardinal ,j4 ,m4 ,thomasius1 ,hymnarium in ,opera1 ii4 #cea seq4 7,rome1 #agdg72 ,a4 ,j4 ,rambach1 ,anthologie christlicher ,gesnge 7,altona1 #ahag72 ,h4 ,a4 ,daniel1 ,thesaurus hymnologicus 7,leipzig1 #e vols41 #ahda-ahef72 ,j4 ,m4 ,neale1 ,hymni ecclesiae et sequentiae 7,london1 #ahea-aheb72 and ,hymns of the ,eastern ,church 7#ahfc74 ,the dissertation prefixed to the second volume of the ,acta sanctorum of the ,bollandists2 ,cardinal ,j4 ,b4 ,pitra1 ,hymnographie de l'glise grecque 7#ahfg71 ,analecta sacra 7#ahgf72 ,w4 ,christ and ,m4 ,paranikas1 ,anthologia ,graeca carminum ,christianorum 7,leipzig1 #ahga72 ,f4 ,a4 ,march1 ,latin ,hymns with ,english ,notes 7,new ,york1 #ahge72 ,r4 ,c4 ,trench1 ,sacred ,latin ,poetry 7,london1 #dth ed41 #ahgd72 ,j4 ,pauly1 ,hymni breviarii ,romani 7,aix-la-,chapelle1 #c vols41 #ahfh-ahgj72 ,pimont1 ,les ,hymnes du brviaire romain 7vols4 #a-c1 #ahgd-ahhd1 unfinished72 ,a4 ,w4 ,f4 ,fischer1 ,kirchenlieder-,lexicon 7,gotha1 #ahgh-ahgi72 ,j4 ,kayser1 ,beitrge zur ,geschichte der ltesten ,kirchenhymnen 7#ahha72 ,m4 ,manitius1 ,geschichte der christlichen lateinischen ,poesie 7,stuttgart1 #ahia72 ,john ,julian1 ,dictionary of ,hymnology 7#ahib1 new ed4 #aijg74 ,for criticisms of metre1 see also ,huemer1 ,untersuchungen ber die ltesten christlichen ,rhythmen 7#ahgi72 ,e4 ,bouvy1 ,potes et mlodes 7,nmes1 #ahhf72 ,c4 ,krumbacher1 ,geschichte der byzantinischen ,literatur 7,munich1 #ahig1 p4 #gjj seq472 ,j4 ,m4 ,neale1 ,latin dissertation prefixed to ,daniel's ,thesaurus1 vol4 #e2 and ,d4 ,j4 ,donahoe1 ,early ,christian ,hymns 7,london1 #aiji74 ,,ii4 ,medieval4--,walafrid ,strabo's treatise1 ch4 #be1 ,de hymnis1 c42 ,radulph of ,tongres1 ,de psaltario observando 7#adth century72 ,clichtavaens1 ,elucidatorium ecclesiasticum 7,paris1 #aeef72 ,faustinus ,arevalus1 ,hymnodia ,hispanica 7,rome1 #aghf72 ,e4 du ,mril1 ,posies populaires latines antrieures au ,,xiiie sicle 7,paris1 #ahdc72 ,j4 ,stevenson1 ,latin ,hymns of the ,anglo-,saxon ,church 7,surtees ,society1 ,durham1 #ahea72 ,norman1 ,hymnarium ,sarisburiense 7,london1 #ahea72 ,j4 ,d4 ,chambers1 ,psalter1 c41 according to the ,sarum use 7#aheb72 ,f4 ,j4 ,mone1 ,lateinische ,hymnen des ,mittelalters 7,freiburg1 #c vols41 #ahec-ahee72 ,ph4 ,wackernagel1 ,das deutsche ,kirchenlied von der ltesten ,zeit bis zum ,anfang des #ag4 ,jahrhunderts1 vol4 i4 7,leipzig1 #ahfd72 ,e4 ,dmmler1 ,potae latini aevi ,carolini 7#ahha-ahij72 the ,hymnologische ,beitrge3 ,quellen und ,forschungen zur ,geschichte der lateinischen ,hymnendichtung1 edited by ,c4 ,blume and ,g4 ,m4 ,dreves 7,leipzig1 #ahig72 ,g4 ,c4 ,f4 ,mohnike1 ,hymnologische ,forschungen2 ,klemming1 ,hymni et sequentiae in regno ,sueciae 7,stockholm1 #d vols41 #ahhe-ahhg72 ,das katholische deutsche ,kirchenlied 7vol4 i4 by ,k4 ,severin ,meister1 #ahfb1 vol4 ii4 by ,w4 ,baumker1 #ahhc72 the ,hymnodia ,hiberica1 ,spanische ,hymnen des ,mittelalters1 vol4 xvi4 7#ahid72 the ,hymnodia ,gotica1 ,mozarabische ,hymnen des altspanischen ,ritus1 vol4 xxvii4 7#ahig72 ,j4 ,dank1 ,vetus hymnarium ecclesiasticae ,hungariae 7,budapest1 #ahic72 ,j4 ,h4 ,bernard and ,r4 ,atkinson1 ,the ,irish ,liber ,hymnorum 7#b vols41 ,london1 #ahih72 ,c4 ,a4 ,j4 ,chevalier1 ,posie liturgique du moyen ge 7,paris1 #ahic74 ,,iii4 ,modern4--,j4 ,c4 ,jacobi1 ,psalmodia ,germanica 7#agbb-agbe and #agcb1 with supplement added by ,j4 ,haberkorn1 #agfe72 ,f4 ,a4 ,cunz1 ,geschichte des deutschen ,kirchenliedes 7,leipzig1 #ahee72 ,baron von ,bunsen1 ,versuch eines allgemeinen ,gesang- und ,gebetbuches 7#ahcc7 and ,allgemeines evangelisches ,gesang- und ,gebetbuch 7#ahdf72 ,catherine ,winkworth1 ,christian ,singers of ,germany 7#ahfi7 and ,lyra ,germanica 7#ahee72 ,catherine ,h4 ,dunn1 ,hymns from the ,german 7#aheg72 ,frances ,e4 ,cox1 ,sacred ,hymns from the ,german 7,london1 #ahda72 ,massie1 ,lyra domestica 7#ahfj72 ,appendix on ,scottish ,psalmody in ,d4 ,laing's edition of ,baillie's ,letters and ,journals 7#ahda-ahdb72 ,j4 and ,c4 ,wesley1 ,collection of ,psalms and ,hymns 7#agda72 ,josiah ,miller1 ,our ,hymns1 their ,authors and ,origin 7#ahff72 ,john ,gadsby1 ,memoirs of the ,principal ,hymn-writers 7#crd ed41 #ahfa72 ,l4 ,c4 ,biggs1 ,annotations to ,hymns ,ancient and ,modern 7#ahfg72 ,daniel ,sedgwick1 ,comprehensive ,index of ,names of ,original ,authors of ,hymns 7#bnd ed41 #ahfc72 ,r4 ,e4 ,prothero1 ,the ,psalms in ,human ,life 7#aijg72 ,c4 ,j4 ,brandt and ,l4 ,helweg1 ,den danske ,psalmedigtning 7,copenhagen1 #ahdf-ahdg72 ,j4 ,n4 ,skaar1 ,norsk ,salmehistorie 7,bergen1 #ahgi-ahhj72 ,h4 ,schck1 ,svensk ,literaturhistoria 7,stockholm1 #ahij72 ,rudolf ,wolkan1 ,geschichte der deutschen ,literatur in ,bhmen1 #bdf-bef1 and ,das deutsche ,kirchenlied der bhm4 ,brder 7,prague1 #ahia72 ,zahn1 ,die geistlichen ,lieder der ,brder in ,bhmen1 ,mhren u4 ,polen 7,nuremberg1 #ahge72 and ,j4 ,mller1 ,bohemian ,brethren's ,hymnody1 in ,j4 ,julian's ,dictionary of ,hymnology4 ,for account of hymn-tunes1 c41 see ,w4 ,cowan and ,james ,love1 ,music of the ,church ,hymnody and the ,psalter in ,metre 7,london1 #aija72 and ,dickinson1 ,music in the ,history of the ,western ,church 7,new ,york1 #aijb72 ,s4 ,kmmerle1 ,encyklopdie der evangelischen ,kirchenmusik 7#d vols41 #ahhh-ahie72 ,chr4 ,palmer1 ,evangelische ,hymnologie 7,stuttgart1 #ahfe72 and ,p4 ,urto ,kornmller1 ,lexikon der kirchlichen ,tonkunst 7#ahia74 ,,footnotes3 #a ,the history of the hymn naturally begins with ,greece1 but it may be found in some form much earlier2 ,assyria and ,egypt have left specimens1 while ,india has the ,vedic hymns1 and ,confucius collected praise songs in ,china4 #b ,see ,,greek ,,literature4 #c ,the authorship of this and of one other1 ,when all thy mercies1 ,o my ,god1 has been made a subject of controversy1--being claimed for ,andrew ,marvell 7who died in #afgh71 in the preface to ,captain ,e4 ,thompson's edition 7#aggf7 of ,marvell's ,works4 ,but this claim does not appear to be substantiated4 ,the editor did not give his readers the means of judging as to the real age1 character or value of a manuscript to which he referred2 he did not say that these portions of it were in ,marvell's handwriting2 he did not even himself include them among ,marvell's poems1 as published in the body of his edition2 and he advanced a like claim on like grounds to two other poems1 in very different styles1 which had been published as their own by ,tickell and ,mallet4 ,it is certain that all the five hymns were first made public in #agab1 in papers contributed by ,addison to the ,spectator 7,nos4 #dda1 #dec1 #dfe1 #dhi1 #eac71 in which they were introduced in a way which might have been expected if they were by the hand which wrote those papers1 but which would have been improbable1 and unworthy of ,addison1 if they were unpublished works of a writer of so much genius1 and such note in his day1 as ,marvell4 ,they are all printed as ,addison's in ,dr ,johnson's ,british ,poets4 #d ,the old tune for the #ajjth ,psalm and ,croft's tune for the #ajdth are almost the only exceptions1 unless ,god save the ,king may be classed under hymnody4 ,in ,scotland also the tune for the #abdth ,psalm is associated with its proper text4 ,,hypaethros 7,gr4 ,greek3 hypaithros1 beneath the sky1 in the open air1 ,greek3 hypo1 beneath1 and ,greek3 aithr1 air71 the ,greek term quoted by ,vitruvius 7iii4 #b7 for the opening in the middle of the roof of decastyle temples1 of which there was no example in ,rome1 but one in ,athens in the temple of ,jupiter ,olympius1 which is octastyle4 ,but at the time he wrote 7c4 #be ,b4,c47 the cella of this temple was unroofed1 because the columns which had been provided to carry1 at all events1 part of the ceiling and roof had been taken away by ,sulla in #hj ,b4,c4 ,the decastyle temple of ,apollo ,didymaeus near ,miletus was1 according to ,strabo 7c4 #ej ,b4,c471 unroofed1 on account of the vastness of its cella1 in which precious groves of laurel bushes were planted4 ,apart from these two examples1 the references in various writers to an opening of some kind in the roofs of temples dedicated to particular deities1 and the statement of ,vitruvius1 which was doubtless based on the writings of ,greek authors1 that in decastyle or large temples the centre was open to the sky and without a roof 7medium autem sub divo est sine tecto71 render the existence of the hypaethros probable in some cases2 and therefore ,c4 ,r4 ,cockerell's discovery in the temple at ,aegina of two fragments of a coping-stone1 in which there were sinkings on one side to receive the tiles and covering tiles1 has been of great importance in the discussion of this subject4 ,in the conjectural restoration of the opaion or opening in the roof shown in ,cockerell's drawing1 it has been made needlessly large1 having an area of about one quarter of the superficial area of the cella between the columns1 and since in the ,pantheon at ,rome the relative proportions of the central opening in the dome and the area of the ,rotunda are #a3 #bb1 and the light there is ample1 in the clearer atmosphere of ,greece it might have been less4 ,the larger the opening the more conspicuous would be the notch in the roof which is so greatly objected to2 in this respect ,t4 ,j4 ,hittorff would seem to be nearer the truth when1 in his conjectural restoration of ,temple ,r4 at ,selinus1 he shows an opaion about half the relative size shown in ,cockerell's of that at ,aegina1 the coping on the side elevation being much less noticeable4 ,the problem was apparently solved in another way at ,bassae1 where1 in the excavations of the temple of ,apollo by ,cockerell and ,baron ,haller von ,hallerstein1 three marble tiles were found with pierced openings in them about #ah in4 by #aj in42 five of these pierced tiles on either side would have amply lighted the interior of the cella1 and the amount of rain passing through 7a serious element to be considered in a country where torrential rains occasionally fall7 would not be very great or more than could be retained to dry up in the cella sunk pavement4 ,in favour of both these methods of lighting the interior of the cella1 the sarcophagus tomb at ,cyrene1 about #bj ft4 long1 carved in imitation of a temple1 has been adduced1 because1 on the top of the roof and in its centre1 there is a raised coping1 and a similar feature is found on a tomb found near ,delos2 an example from ,crete now in the ,british ,museum shows a pierced tile on each side of the roof1 and a large number of pierced tiles have been found in ,pompeii1 some of them surrounded with a rim identical with that of the marble tiles at ,bassae4 ,on the other hand1 there are many authorities1 among them ,dr ,w4 ,drpfeld1 who have adhered to their original opinion that it was only through the open doorway that light was ever admitted into the cella1 and with the clear atmosphere of ,greece and the reflections from the marble pavement such lighting would be quite sufficient4 ,there remains still another source of light to be considered1 that passing through the ,parian marble tiles of the roof2 the superior translucency of ,parian to any other marble may have suggested its employment for the roofs of temples1 and if1 in the framed ceilings carried over the cella1 openings were left1 some light from the ,parian tile roof might have been obtained4 ,it is possibly to this that ,plutarch refers when describing the ceiling and roof of the temple of ,demeter at ,eleusis1 where the columns in the interior of the temple carried a ceiling1 probably constructed of timbers crossing one another at right angles1 and one or more of the spaces was left open1 which ,xenocles surmounted by a roof formed of tiles4 ,james ,fergusson put forward many years ago a conjectural restoration in which he adopted a clerestory above the superimposed columns inside the cella2 in order to provide the light for these windows he indicated two trenches in the roof1 one on each side1 and pointed out that the great ,hall of ,columns at ,karnak was lighted in this way with clerestory windows2 but in the first place the light in the latter was obtained over the flat roofs covering lower portions of the hall1 and in the second place1 as it rarely rains in ,thebes1 there could be no difficulty about the drainage1 while in ,greece1 with the torrential rains and snow1 these trenches would be deluged with water1 and with all the appliances of the present day it would be impossible to keep these clerestory windows watertight4 ,there is1 however1 still another objection to ,fergusson's theory2 the water collecting in these trenches on the roof would have to be discharged1 for which ,fergusson's suggestions are quite inadequate1 and the gargoyles shown in the cella wall would make the peristyle insupportable just at the time when it was required for shelter4 ,no drainage otherwise of any kind has ever been found in any ,greek temple1 which is fatal to ,fergusson's view4 ,nor is it in accordance with the definition open to the sky4 ,english cathedrals and churches are all lighted by clerestory windows1 but no one has described them as open to the sky1 and although ,vitruvius's statements are sometimes confusing1 his description is far too clear to leave any misunderstanding as to the lighting of temples 7where it was necessary on account of great length7 through an opening in the roof4 ,there is one other theory which has been put forward1 but which can only apply to non-peristylar temples1--that light and air was admitted through the metopes1 the apertures between the beams crossing the cella1--and it has been assumed that because ,orestes was advised in one of the ,greek plays to climb up and look through the metopes of the temple1 these were left open2 but if ,orestes could look in1 so could the birds1 and the statue of the god would be defiled4 ,the metopes were probably filled in with shutters of some kind which ,orestes knew how to open4 7,r4 ,p4 ,s47 ,,hypallage 7,gr4 ,greek3 hypallag1 interchange or exchange71 a rhetorical figure1 in which the proper relation between two words according to the rules of syntax are inverted4 ,the stock instance is that in ,virgil1 ,aen4 iii4 #fa1 where dare classibus austros1 to give winds to the fleet1 is put for dare classes austris1 to give the fleet to the winds4 ,the term is also loosely applied to figures of speech properly known as metonymy and1 generally1 to any striking turn of expression4 ,,hypatia 7,greek3 ,hypatia7 7c4 ,a4,d4 #cgj-dae7 mathematician and philosopher1 born in ,alexandria1 was the daughter of ,theon1 also a mathematician and philosopher1 author of scholia on ,euclid and a commentary on the ,almagest1 in which it is suggested that he was assisted by ,hypatia 7on the #crd book74 ,after lecturing in her native city1 ,hypatia ultimately became the recognized head of the ,neoplatonic school there 7c4 #djj74 ,her great eloquence and rare modesty and beauty1 combined with her remarkable intellectual gifts1 attracted to her class-room a large number of pupils4 ,among these was ,synesius1 afterwards 7c4 #daj7 bishop of ,ptolemas1 several of whose letters to her1 full of chivalrous admiration and reverence1 are still extant4 ,suidas1 misled by an incomplete excerpt in ,photius from the life of ,isidorus 7the ,neoplatonist7 by ,damascius1 states that ,hypatia was the wife of ,isidorus2 but this is chronologically impossible1 since ,isidorus could not have been born before #dcd 7see ,hoche in ,philologus74 ,shortly after the accession of ,cyril to the patriarchate of ,alexandria in #dab1 owing to her intimacy with ,orestes1 the pagan prefect of the city1 ,hypatia was barbarously murdered by the ,nitrian monks and the fanatical ,christian mob 7,march #dae74 ,socrates has related how she was torn from her chariot1 dragged to the ,caesareum 7then a ,christian church71 stripped naked1 done to death with oyster-shells 7,greek3 ostrakois aneilon1 perhaps cut her throat7 and finally burnt piecemeal4 ,most prominent among the actual perpetrators of the crime was one ,peter1 a reader2 but there seems little reason to doubt ,cyril's complicity 7see ,,cyril ,,of ,,alexandria74 ,hypatia1 according to ,suidas1 was the author of commentaries on the ,arithmetica of ,diophantus of ,alexandria1 on the ,conics of ,apollonius of ,perga and on the astronomical canon 7of ,ptolemy74 ,these works are lost2 but their titles1 combined with expressions in the letters of ,synesius1 who consulted her about the construction of an astrolabe and a hydroscope1 indicate that she devoted herself specially to astronomy and mathematics4 ,little is known of her philosophical opinions1 but she appears to have embraced the intellectual rather than the mystical side of ,neoplatonism1 and to have been a follower of ,plotinus rather than of ,porphyry and ,iamblichus4 ,zeller1 however1 in his ,outlines of ,greek ,philosophy 7#ahhf1 ,eng4 trans4 p4 #cdg71 states that she appears to have taught the ,neoplatonic doctrine in the form in which ,iamblichus had stated it4 ,a ,latin letter to ,cyril on behalf of ,nestorius1 printed in the ,collectio nova conciliorum1 i4 7#afbc71 by ,stephanus ,baluzius 7tienne ,baluze1 q4v471 and sometimes attributed to her1 is undoubtedly spurious4 ,the story of ,hypatia appears in a considerably disguised yet still recognizable form in the legend of ,st ,catherine as recorded in the ,roman ,breviary 7,november #be71 and still more fully in the ,martyrologies 7see ,a4 ,b4 ,jameson1 ,sacred and ,legendary ,art 7#ahfg7 ii4 #dfg47 ,the chief source for the little we know about ,hypatia is the account given by ,socrates 7,hist4 ecclesiastica1 vii4 #ae74 ,she is the subject of an epigram by ,palladas in the ,greek ,anthology 7ix4 #djj74 ,see ,fabricius1 ,bibliotheca ,graeca 7ed4 ,harles71 ix4 #ahg2 ,john ,toland1 ,tetradymus 7#agbj72 ,r4 ,hoche in ,philologus 7#ahfj71 xv4 #dce2 monographs by ,stephan ,wolf 7,czernowitz1 #ahgi71 ,h4 ,ligier 7,dijon1 #ahhj7 and ,w4 ,a4 ,meyer 7,heidelberg1 #ahhe71 who devotes attention to the relation of ,hypatia to the chief representatives of ,neoplatonism2 ,j4 ,b4 ,bury1 ,hist4 of the ,later ,roman ,empire 7#ahhi71 i4 #bjh1cag2 ,a4 ,gldenpenning1 ,geschichte des ostrmischen ,reiches unter ,arcadius und ,theodosius ,,ii4 7,halle1 #ahhe71 p4 #bcj2 ,wetzer and ,welte1 ,kirchenlexikon1 vi4 7#ahhi71 from a ,catholic standpoint4 ,the story of ,hypatia also forms the basis of the well-known historical romance by ,charles ,kingsley 7#ahec74 ,,hyperbaton 7,gr4 ,greek3 huperbaton1 a stepping over71 the name of a figure of speech1 consisting of a transposition of words from their natural order1 such as the placing of the object before instead of after the verb4 ,it is a common method of securing emphasis4 ,,hyperbola1 a conic section1 consisting of two open branches1 each extending to infinity4 ,it may be defined in several ways4 ,the in solido definition as the section of a cone by a plane at a less inclination to the axis than the generator brings out the existence of the two infinite branches if we imagine the cone to be double and to extend to infinity4 ,the in plano definition1 i4e4 as the conic having an eccentricity greater than unity1 is a convenient starting-point for the ,euclidian investigation4 ,in projective geometry it may be defined as the conic which intersects the line at infinity in two real points1 or to which it is possible to draw two real tangents from the centre4 ,analytically1 it is defined by an equation of the second degree1 of which the highest terms have real roots 7see ,,conic ,,section74 ,while resembling the parabola in extending to infinity1 the curve has closest affinities to the ellipse4 ,thus it has a real centre1 two foci1 two directrices and two vertices2 the transverse axis1 joining the vertices1 corresponds to the major axis of the ellipse1 and the line through the centre and perpendicular to this axis is called the conjugate axis1 and corresponds to the minor axis of the ellipse2 about these axes the curve is symmetrical4 ,the curve does not appear to intersect the conjugate axis1 but the introduction of imaginaries permits us to regard it as cutting this axis in two unreal points4 ,calling the foci ,s1 ,s1 the real vertices ,a1 ,a1 the extremities of the conjugate axis ,b1 ,b' and the centre ,c1 the positions of ,b1 ,b are given by ,,ab ,,ab ,,cs4 ,if a rectangle be constructed about ,,aa and ,,bb1 the diagonals of this figure are the asymptotes of the curve2 they are the tangents from the centre1 and hence touch the curve at infinity4 ,these two lines may be pictured in the in solido definition as the section of a cone by a plane through its vertex and parallel to the plane generating the hyperbola4 ,if the asymptotes be perpendicular1 or1 in other words1 the principal axes be equal1 the curve is called the rectangular hyperbola4 ,the hyperbola which has for its transverse and conjugate axes the transverse and conjugate axes of another hyperbola is said to be the conjugate hyperbola4 ,some properties of the curve will be briefly stated3 ,if ,,pn be the ordinate of the point ,p on the curve1 ,,aa' the vertices1 ,x the meet of the directrix and axis and ,c the centre1 then ,,pn3 ,,an,,na3 3 ,,sx3 ,,ax,a,x1 i4e4 ,,pn is to ,,an,,na in a constant ratio4 ,the circle on ,,aa' as diameter is called the auxiliarly circle2 obviously ,,an,,na' equals the square of the tangent to this circle from ,n1 and hence the ratio of ,,pn to the tangent to the auxiliarly circle from ,n equals the ratio of the conjugate axis to the transverse4 ,we may observe that the asymptotes intersect this circle in the same points as the directrices4 ,an important property is3 the difference of the focal distances of any point on the curve equals the transverse axis4 ,the tangent at any point bisects the angle between the focal distances of the point1 and the normal is equally inclined to the focal distances4 ,also the auxiliarly circle is the locus of the feet of the perpendiculars from the foci on any tangent4 ,two tangents from any point are equally inclined to the focal distance of the point4 ,if the tangent at ,p meet the conjugate axis in t1 and the transverse in ,n1 then ,ct4 ,,pn ,,bc2 similarly if g and ,g be the corresponding intersections of the normal1 ,,pg 3 ,pg 3 3 ,,bc 3 ,,ac4 ,a diameter is a line through the centre and terminated by the curve3 it bisects all chords parallel to the tangents at its extremities2 the diameter parallel to these chords is its conjugate diameter4 ,any diameter is a mean proportional between the transverse axis and the focal chord parallel to the diameter4 ,any line cuts off equal distances between the curve and the asymptotes4 ,if the tangent at ,p meets the asymptotes in ,r1 ,r'1 then ,,cr,,cr ,,cs4 ,the geometry of the rectangular hyperbola is simplified by the fact that its principal axes are equal4 ,analytically the hyperbola is given by ax #b;hxy by #b;gx #b;fy c #j wherein ab h4 ,referred to the centre this becomes ,ax #b;,hxy ,by ,c #j2 and if the axes of coordinates be the principal axes of the curve1 the equation is further simplified to ,ax - ,by ,c1 or if the semi-transverse axis be a1 and the semi-conjugate b1 x_/a - y_/b #a4 ,this is the most commonly used form4 ,in the rectangular hyperbola a b2 hence its equation is x - y #j4 ,the equations to the asymptotes are x_/a y_/b and x y respectively4 ,referred to the asymptotes as axes the general equation becomes xy k2 obviously the axes are oblique in the general hyperbola and rectangular in the rectangular hyperbola4 ,the values of the constant k are 7a b7 and a respectively4 7,see ,,geometry3 ,analytical2 ,projective47 ,,hyperbole 7from ,gr4 ,greek3 hyperballein1 to throw beyond71 a figure of rhetoric whereby the speaker expresses more than the truth1 in order to produce a vivid impression2 hence1 an exaggeration4 ,,hyperboreans 7,greek3 ,hyperboreoi1 ,hyperboreioi71 a mythical people intimately connected with the worship of ,apollo4 ,their name does not occur in the ,iliad or the ,odyssey1 but ,herodotus 7iv4 #cb7 states that they were mentioned in ,hesiod and in the ,epigoni1 an epic of the ,theban cycle4 ,according to ,herodotus1 two maidens1 ,opis and ,arge1 and later two others1 ,hyperoche and ,laodice1 escorted by five men1 called by the ,delians ,perpheres1 were sent by the ,hyperboreans with certain offerings to ,delos4 ,finding that their messengers did not return1 the ,hyperboreans adopted the plan of wrapping the offerings in wheat-straw and requested their neighbours to hand them on to the next nation1 and so on1 till they finally reached ,delos4 ,the theory of ,h4 ,l4 ,ahrens1 that ,hyperboreans and ,perpheres are identical1 is now widely accepted4 ,in some of the dialects of northern ,greece 7especially ,macedonia and ,delphi7 phi had a tendency to become beta4 ,the original form of ,greek3 ,perpherees was ,greek3 hyperpheretai or ,greek3 hyperphoroi 7those who carry over71 which becoming ,greek3 hyperboroi gave rise to the popular derivation from ,greek3 boreas 7dwellers beyond the north wind74 ,the ,hyperboreans were thus the bearers of the sacrificial gifts to ,apollo over land and sea1 irrespective of their home1 the name being given to ,delphians1 ,thessalians1 ,athenians and ,delians4 ,it is objected by ,o4 ,schrder that the form ,greek3 ,perpherees requires a passive meaning1 those who are carried round the altar1 perhaps dancers like the whirling dervishes2 distinguishing them from the ,hyperboreans1 he explains the latter as those who live above the mountains1 that is1 in heaven4 ,under the influence of the derivation from ,greek3 boreas1 the home of the ,hyperboreans was placed in a region beyond the north wind1 a paradise like the ,elysian plains1 inaccessible by land or sea1 whither ,apollo could remove those mortals who had lived a life of piety4 ,it was a land of perpetual sunshine and great fertility2 its inhabitants were free from disease and war4 ,the duration of their life was #ajjj years1 but if any desired to shorten it1 he decked himself with garlands and threw himself from a rock into the sea4 ,the close connexion of the ,hyperboreans with the cult of ,apollo may be seen by comparing the ,hyperborean myths1 the characters of which by their names mostly recall ,apollo or ,artemis 7,agyieus1 ,opis1 ,hecaergos1 ,loxo71 with the ceremonial of the ,apolline worship4 ,no meat was eaten at the ,pyanepsia2 the ,hyperboreans were vegetarians4 ,at the festival of ,apollo at ,leucas a victim flung himself from a rock into the sea1 like the ,hyperborean who was tired of life4 ,according to an ,athenian decree 7#chj ,b4,c47 asses were sacrificed to ,apollo at ,delphi1 and ,pindar 7,pythia1 x4 #cc7 speaks of hecatombs of asses being offered to him by the ,hyperboreans4 ,as the latter conveyed sacrificial gifts to ,delos hidden in wheat-straw1 so at the ,thargelia a sheaf of corn was carried round in procession1 concealing a symbol of the god 7for other resemblances see ,crusius's article74 ,although the ,hyperborean legends are mainly connected with ,delphi and ,delos1 traces of them are found in ,argos 7the stories of ,heracles1 ,perseus1 ,io71 ,attica1 ,macedonia1 ,thrace1 ,sicily and ,italy 7which ,niebuhr indeed considers their original home74 ,in modern times the name has been applied to a group of races1 which includes the ,chukchis1 ,koryaks1 ,yukaghirs1 ,ainus1 ,gilyaks and ,kamchadales1 inhabiting the arctic regions of ,asia and ,america4 ,but if ever ethnically one1 the ,asiatic and ,american branches are now as far apart from each other as they both are from the ,mongolo-,tatar stock4 ,see ,o4 ,crusius in ,roscher's ,lexikon der ,mythologie2 ,o4 ,schrder in ,archiv fr ,religionswissenschaft 7#aijd71 viii4 #fi2 ,w4 ,mannhardt1 ,wald- und ,feldkulte 7#aije72 ,l4 ,r4 ,farnell1 ,cults of the ,greek ,states 7#aijg71 iv4 #ajj4 ,,hypereides 7c4 #cij-cbb ,b4,c471 one of the ten ,attic orators1 was the son of ,glaucippus1 of the deme of ,collytus4 ,having studied under ,isocrates1 he began life as a writer of speeches for the courts1 and in #cfj he prosecuted ,autocles1 a general charged with treason in ,thrace 7frags4 #ee-fe1 ,blass74 ,at the time of the so-called ,social ,war 7#ceh-cee7 he accused ,aristophon1 then one of the most influential men at ,athens1 of malpractices 7frags4 #dj-dd1 ,blass71 and impeached ,philocrates 7#cdc7 for high treason4 ,from the peace of #cdf to #cbd ,hypereides supported ,demosthenes in the struggle against ,macedon2 but in the affair of ,harpalus he was one of the ten public prosecutors of ,demosthenes1 and on the exile of his former leader he became the head of the patriotic party 7#cbd74 ,after the death of ,alexander1 he was the chief promoter of the ,lamian war against ,antipater and ,craterus4 ,after the decisive defeat at ,crannon 7#cbb71 ,hypereides and the other orators1 whose surrender was demanded by ,antipater1 were condemned to death by the ,athenian partisans of ,macedonia4 ,hypereides fled to ,aegina1 but ,antipater's emissaries dragged him from the temple of ,aeacus1 where he had taken refuge1 and put him to death2 according to others1 he was taken before ,antipater at ,athens or ,cleonae4 ,his body was afterwards removed to ,athens for burial4 ,hypereides was an ardent pursuer of the beautiful1 which in his time generally meant pleasure and luxury4 ,his temper was easy-going and humorous2 and hence1 though in his development of the periodic sentence he followed ,isocrates1 the essential tendencies of his style are those of ,lysias1 whom he surpassed1 however1 in the richness of his vocabulary and in the variety of his powers4 ,his diction was plain and forcible1 though he occasionally indulged in long compound words probably borrowed from the ,middle ,comedy1 with which1 and with the everyday life of his time1 he was in full sympathy4 ,his composition was simple4 ,he was specially distinguished for subtlety of expression1 grace and wit1 as well as for tact in approaching his case and handling his subject matter4 ,sir ,r4 ,c4 ,jebb sums up the criticism of pseudo-,longinus 7,de sublimitate1 #cd7 in the phrase--,hypereides was the ,sheridan of ,athens4 ,seventy-seven speeches were attributed to ,hypereides1 of which twenty-five were regarded as spurious even by ancient critics4 ,it is said that a ,,ms4 of most of the speeches was in existence in the #afth century in the library of ,matthias ,corvinus1 king of ,hungary1 at ,ofen1 but was destroyed at the capture of the city by the ,turks in #aebf4 ,only a few fragments were known until comparatively recent times4 ,in #ahdg large fragments of his speeches ,against ,demosthenes 7see above7 and ,for ,lycophron 7incidentally interesting as elucidating the order of marriage processions and other details of ,athenian life1 and the ,athenian government of ,lemnos71 and the whole of the ,for ,euxenippus 7c4 #ccj1 a locus classicus on ,greek3 eisangeliai or state prosecutions71 were found in a tomb at ,thebes in ,egypt1 and in #ahef a considerable portion of a ,greek3 logos epitaphios1 a ,funeral ,oration over ,leosthenes and his comrades who had fallen in the ,lamian war1 the best extant specimen of epideictic oratory 7see ,,babington1 ,,churchill74 ,towards the end of the century further discoveries were made of the conclusion of the speech ,against ,philippides 7dealing with a ,greek3 graph paranomn1 or indictment for the proposal of an unconstitutional measure1 arising out of the disputes of the ,macedonian and anti-,macedonian parties at ,athens71 and of the whole of the ,against ,athenogenes 7a perfumer accused of fraud in the sale of his business74 ,these have been edited by ,f4 ,g4 ,kenyon 7#ahic74 ,an important speech that is lost is the ,deliacus 7frags4 #fg-ge1 ,blass7 on the presidency of the ,delian temple claimed by both ,athens and ,delos1 which was adjudged by the ,amphictyons to ,athens4 ,on ,hypereides generally see pseudo-,plutarch1 ,decem oratorum vitae2 ,f4 ,blass1 ,attische ,beredsamkeit1 iii42 ,r4 ,c4 ,jebb1 ,attic ,orators1 ii4 #cha4 ,a full list of editions and articles is given in ,f4 ,blass1 ,hyperidis orationes sex cum ceterarum fragmentis 7#ahid1 ,teubner series71 to which may be added ,i4 ,bassi1 ,le ,quattro ,orazioni di ,iperide 7introduction and notes1 #ahhh71 and ,j4 ,e4 ,sandys in ,classical ,review 7,january #ahie7 7a review of the editions of ,kenyon and ,blass74 ,for the discourse against ,athenogenes see ,h4 ,weil1 tudes sur l'antiquit grecque 7#aijj74 ,,hyperion1 in ,greek mythology1 one of the ,titans1 son of ,uranus and ,gaea and father of ,helios1 the sun-god 7,hesiod1 ,theog4 #acd1 #cga2 ,apollodorus i4 #a4 #b74 ,in the well-known passage in ,shakespeare 7,hamlet1 i4 #b3 ,hyperion to a satyr1 where as in other poets the vowel -i- though really long1 is shortened for metrical reasons7 ,hyperion is used for ,apollo as expressive of the idea of beauty4 ,the name is often used as an epithet of ,helios1 who is himself sometimes called simply ,hyperion4 ,it is explained as 7#a7 he who moves above 7,greek3 hyper-in71 but the quantity of the vowel is against this2 7#b7 he who is above 7,greek3 hyperi-n74 ,others take it to be a patronymic in form1 like ,greek3 ,kronin1 ,molin4 ,,hypersthene1 a rock-forming mineral belonging to the group of orthorhombic pyroxenes4 ,it differs from the other members 7enstatite q4v4 and bronzite7 of this group in containing a considerable amount of iron replacing magnesium3 the chemical formula is 7,mg1 ,fe7,si,o#c4 ,distinctly developed crystals are rare1 the mineral being usually found as foliated masses embedded in those igneous rocks--norite1 hypersthene-andesite1 c4--of which it forms an essential constituent4 ,the coarsely grained labradorite-hypersthene-rock 7norite7 of the island of ,st ,paul off the coast of ,labrador has furnished the most typical material2 and for this reason the mineral has been known as ,labrador hornblende or paulite4 ,the colour is brownish-black1 and the pleochrism strong2 the hardness is #f1 and the specific gravity #c4d-c4e4 ,on certain surfaces it displays a brilliant copper-red metallic sheen or schiller1 which has the same origin as the bronzy sheen of bronzite 7q4v471 but is even more pronounced4 ,like bronzite1 it is sometimes cut and polished for ornamental purposes4 7,l4 ,j4 ,s47 ,,hypertrophy 7,gr4 ,greek3 hyper1 over1 and ,greek3 troph1 nourishment71 a term in medicine employed to designate an abnormal increase in bulk of one or more of the organs or component tissues of the body 7see ,,pathology74 ,in its strict sense this term can only be applied where the increase affects the natural textures of a part1 and is not applicable where the enlargement is due to the presence of some extraneous morbid formation4 ,hypertrophy of a part may manifest itself either by simply an increase in the size of its constituents1 or by this combined with an increase in their number 7hyperplasia74 ,in many instances both are associated4 ,the conditions giving rise to hypertrophy are the reverse of those described as producing ,atrophy 7q4v474 ,they are concisely stated by ,sir ,james ,paget as being chiefly or only three1 namely3 7#a7 the increased exercise of a part in its healthy functions2 7#b7 an increased accumulation in the blood of the particular materials which a part appropriates to its nutrition or in secretion2 and 7#c7 an increased afflux of healthy blood4 ,illustrations are furnished of the first of these conditions by the high development of muscular tissue under habitual active exercise2 of the second in the case of obesity1 which is an hypertrophy of the fatty tissues1 the elements of which are furnished by the blood2 and of the third in the occasional overgrowth of hair in the neighbourhood of parts which are the seat of inflammation4 ,obviously therefore1 in many instances1 hypertrophy cannot be regarded as a deviation from health1 but rather on the contrary as indicative of a high degree of nutrition and physical power4 ,even in those cases where it is found associated with disease1 it is often produced as a salutary effort of nature to compensate for obstructions or other difficulties which have arisen in the system1 and thus to ward off evil consequences4 ,no better example of this can be seen than in the case of certain forms of heart disease1 where from defect at some of the natural orifices of that organ the onward flow of the blood is interfered with1 and would soon give rise to serious embarrassment to the circulation1 were it not that behind the seat of obstruction the heart gradually becomes hypertrophied1 and thus acquires greater propelling power to overcome the resistance in front4 ,again1 it has been noticed1 in the case of certain double organs such as the kidneys1 that when one has been destroyed by disease the other has become hypertrophied to such a degree as enables it to discharge the functions of both4 ,hypertrophy may1 however1 in certain circumstances constitute a disease1 as in goitre and elephantiasis 7q4v471 and also in the case of certain tumours and growths 7such as cutaneous excrescences1 fatty tumours1 mucous polypi1 c471 which are simply enlargements of normal textures4 ,hypertrophy does not in all cases involve an increase in bulk2 for1 just as in atrophy there may be no diminution in the size of the affected organ1 so in hypertrophy there may be no increase4 ,this is apt to be the case where certain only of the elements of an organ undergo increase1 while the others remain unaffected or are actually atrophied by the pressure of the hypertrophied tissue1 as is seen in the disease known as cirrhosis of the liver4 ,a spurious hypertrophy is observed in the rare disease to which ,g4 ,b4 ,duchenne applied the name of pseudo-hypertrophic paralysis4 ,this ailment1 which appears to be confined to children1 consists essentially of a progressive loss of power accompanied with a remarkable enlargement of certain muscles or groups of muscles1 more rarely of the whole muscular system4 ,this increase of bulk is1 however1 not a true hypertrophy1 but rather an excessive development of connective tissue in the substance of the muscles1 the proper texture of which tends in consequence to undergo atrophy or degeneration4 ,the appearance presented by a child suffering from this disease is striking4 ,the attitude and gait are remarkably altered1 the child standing with shoulders thrown back1 small of the back deeply curved inwards1 and legs wide apart1 while walking is accompanied with a peculiar swinging or rocking movement4 ,the calves of the legs1 the buttocks1 the muscles of the back1 and occasionally other muscles1 are seen to be unduly enlarged1 and contrast strangely with the general feebleness4 ,the progress of the disease is marked by increasing failure of locomotory power1 and ultimately by complete paralysis of the limbs4 ,the malady is little amenable to treatment1 and1 although often prolonged for years1 generally proves fatal before the period of maturity4 ,,hypnotism1 a term now in general use as covering all that pertains to the art of inducing the hypnotic state1 or hypnosis1 and to the study of that state1 its conditions1 peculiarities and effects4 ,hypnosis is a condition1 allied to normal sleep 7,gr4 ,greek3 hypnos71 which can be induced in a large majority of normal persons4 ,its most characteristic and constant symptom is the increased suggestibility of the subject 7see ,,suggestion74 ,other symptoms are very varied and differ widely in different subjects and in the same subject at different times4 ,there can be no doubt that the increased suggestibility and all the other symptoms of hypnosis imply some abnormal condition of the brain of a temporary and harmless nature4 ,it would seem that in all ages and in almost all countries individuals have occasionally fallen into abnormal states of mind more or less closely resembling the hypnotic state1 and have thereby excited the superstitious wonder of their fellows4 ,in some cases the state has been deliberately induced1 in others it has appeared spontaneously1 generally under the influence of some emotional excitement4 ,the most familiar of these allied states is the somnambulism or sleep-walking to which some persons seem to be hereditarily disposed4 ,of a rather different type are the states of ecstasy into which religious enthusiasts have occasionally fallen and which were especially frequent among the peoples of ,europe during the middle ages4 ,while in this condition individuals have appeared to be insensitive to all impressions made on their sense-organs1 even to such as would excite acute pain in normal persons1 have been capable of maintaining rigid postures for long periods of time1 have experienced vivid hallucinations1 and have produced1 through the power of the imagination1 extraordinary organic changes in the body1 such as the bloody stigmata on the hands and feet in several well-attested instances4 ,it has been proved in recent years that effects of all these kinds may be produced by hypnotic suggestion4 ,different again1 but closely paralleled by some subjects in hypnosis1 is the state of latah into which a certain proportion of persons of the ,malay race are liable to fall4 ,these persons1 if their attention is suddenly and forcibly drawn to any other person1 will begin to imitate his every action and attitude1 and may do so in spite of their best efforts to restrain their imitative movements4 ,among the half-bred ,french-,canadians of the forest regions of ,canada occur individuals1 known as jumpers1 who are liable to fall suddenly into a similar state of abject imitativeness1 and the same peculiar behaviour has been observed among some of the remote tribes of ,siberia4 ,the deliberate induction of states identical with1 or closely allied to1 hypnosis is practised by many barbarous and savage peoples1 generally for ceremonial purposes4 ,thus1 certain dervishes of ,algiers are said to induce in themselves1 by the aid of the sound of drums1 monotonous songs and movements1 a state in which they are insensitive to pain1 and a similar practice of religious devotees is reported from ,tibet4 ,perhaps the most marvellous achievement among well-attested cases of this sort is that of certain yogis of ,hindustan2 by long training and practice they seem to acquire the power of arresting almost completely all their vital functions4 ,an intense effort of abstraction from the impressions of the outer world1 a prolonged fixation of the eyes upon the nose or in some other strained position and a power of greatly slowing the respiration1 these seem to be important features of their procedure for the attainment of their abnormal states4 ,in spite of the wide distribution in time and space1 and the not very infrequent occurrence1 of these instances of states identical with or allied to hypnosis1 some three centuries of enthusiastic investigation and of bitter controversy were required to establish the occurrence of the hypnotic state among the facts accepted by the world of ,european science4 ,scientific interest in them may be traced back at least as far as the end of the #afth century4 ,paracelsus had founded the sympathetic system of medicine1 according to which the stars and other bodies1 especially magnets1 influence men by means of a subtle emanation or fluid that pervades all space4 ,j4 ,b4 van ,helmont1 a distinguished man of science of the latter part of the #afth century1 extended this doctrine by teaching that a similar magnetic fluid radiates from men1 and that it can be guided by their wills to influence directly the minds and bodies of others4 ,in the middle of the #agth century there appeared in ,england several persons who claimed to have the power of curing diseases by stroking with the hand4 ,notable amongst these was ,valentine ,greatrakes1 of ,affane1 in the county of ,waterford1 ,ireland1 who was born in ,february #afbh1 and who attracted great attention in ,england by his supposed power of curing the king's evil1 or scrofula4 ,many of the most distinguished scientific and theological men of the day1 such as ,robert ,boyle and ,r4 ,cudworth1 witnessed and attested the cures supposed to be effected by ,greatrakes1 and thousands of sufferers crowded to him from all parts of the kingdom4 ,about the middle of the #ahth century ,john ,joseph ,gassner1 a ,roman ,catholic priest in ,swabia1 took up the notion that the majority of diseases arose from demoniacal possession1 and could only be cured by exorcism4 ,his method was undoubtedly similar to that afterwards followed by ,mesmer and others1 and he had an extraordinary influence over the nervous systems of his patients4 ,gassner1 however1 believed his power to be altogether supernatural4 ,but it was not until the latter part of the #ahth century that the doctrine of a magnetic fluid excited great popular interest and became the subject of fierce controversy in the scientific world4 ,f4 ,a4 ,mesmer 7q4v471 a physician of ,vienna1 was largely instrumental in bringing the doctrine into prominence4 ,he developed it by postulating a specialized variety of magnetic fluid which he called animal magnetism2 and he claimed to be able to cure many diseases by means of this animal magnetism1 teaching1 also1 that it may be imparted to and stored up in inert objects1 which are thereby rendered potent to cure disease4 ,it would seem that ,mesmer himself was not acquainted with the artificial somnambulism which for nearly a century was called mesmeric or magnetic sleep1 and which is now familiar as hypnosis of a well-marked degree4 ,it was observed and described about the year #aghj by the marquis de ,puysgur1 a disciple of ,mesmer1 who showed that1 while subjects were in this state1 not only could some of their diseases be cured1 but also their movements could be controlled by the magnetizer1 and that they usually remembered nothing of the events of the period of sleep when restored to normal consciousness4 ,these are three of the most important features of hypnosis1 and the modern study of hypnotism may therefore be said to have been initiated at this date by ,puysgur4 ,for1 though it is probable that this state had often been induced by the earlier magnetists1 they had not recognized that the peculiar behaviour of their patients resulted from their being plunged into this artificial sleep1 but had attributed all the symptoms they observed to the direct physical action of external agents upon the patients4 ,the success of ,mesmer and his disciples1 especially great in the fashionable world1 led to the appointment in ,paris of a royal commission for the investigation of their claims4 ,the commission1 which included men of great eminence1 notably ,a4 ,l4 ,lavoisier and ,benjamin ,franklin1 reported in the year #aghd that it could not accept the evidence for the existence of the magnetic fluid2 but it did not express an opinion as to the reality of the cures said to be effected by its means1 nor as to the nature of the magnetic sleep4 ,this report and the social upheavals of the following years seem to have abolished the public interest in animal magnetism for the space of one generation2 after which ,alexandre ,bertrand1 a ,parisian physician1 revived it by his acute investigations and interpretations of the phenomena4 ,bertrand was the first to give an explanation of the facts of the kind that is now generally accepted4 ,he exhibited the affinity of the magnetic sleep to ordinary somnambulism1 and he taught that the peculiar effects are to be regarded as due to the suggestions of the operator working themselves out in the mind and body of the magnetized subject1 i4e4 he regarded the influence of the magnetizer as exerted in the first instance on the mind of the subject and only indirectly through the mind upon the body4 ,shortly after this revival of public interest1 namely in the year #ahca1 a committee of the ,academy of ,medicine of ,paris reported favourably upon magnetism as a therapeutic agency1 and before many years had elapsed it was extensively practised by the physicians of all ,european countries1 with few exceptions1 of which ,england was the most notable4 ,most of the practitioners of this period adhered to the doctrine of the magnetic fluid emanating from the operator to his patient1 and the acceptance of this doctrine was commonly combined with belief in phrenology1 astrology and the influence of metals and magnets1 externally applied1 in curing disease and in producing a variety of strange sensations and other affections of the mind4 ,these beliefs1 claiming to rest upon carefully observed facts1 were given a new elaboration and a more imposing claim to be scientifically established by the doctrine of odylic force propounded by ,baron ,karl von ,reichenbach4 ,in this mass of ill-based assertion and belief the valuable truths of animal magnetism and the psychological explanations of them given by ,bertrand were swamped and well-nigh lost sight of4 ,for it was this seemingly inseparable association between the facts of hypnotism and these bizarre practices and baseless beliefs that blinded the larger and more sober part of the scientific world1 and led them persistently to assert that all this group of alleged phenomena was a mass of quackery1 fraud and superstition4 ,and the fact that magnetism was practised for pecuniary gain1 often in a shameless manner1 by exponents who claimed to cure by its means every conceivable ill1 rendered this attitude on the part of the medical profession inevitable and perhaps excusable1 though not justifiable4 ,it was owing to this baleful association that ,john ,elliotson1 one of the leading ,london physicians of that time1 who became an ardent advocate of magnetism and who founded and edited the ,zoist in the interests of the subject1 was driven out of the profession4 ,this association may perhaps be held1 also1 to excuse the hostile attitude of the medical profession towards ,james ,esdaile1 a surgeon1 who1 practising in a government hospital in ,calcutta among the natives of ,india1 performed many major operations1 such as the amputation of limbs1 painlessly and with the most excellent results by aid of the magnetic sleep4 ,for both ,elliotson and ,esdaile1 though honourable practitioners1 accepted the doctrine of the magnetic fluid and many of the erroneous beliefs that commonly were bound up with it4 ,in #ahda ,james ,braid1 a surgeon of ,manchester1 rediscovered independently ,bertrand's physiological and psychological explanations of the facts1 carried them further1 and placed hypnotism1 as he named the study1 on a sound basis4 ,braid showed that subjects in magnetic sleep1 far from being in a profoundly insensitive condition1 are often abnormally susceptible to impressions on the senses1 and showed that many of the peculiarities of their behaviour were due to suggestions1 made verbally or otherwise1 but unintentionally1 by the operator or by onlookers4 ,it seems1 on looking back on the history of hypnotism1 that at this time it was in a fair way to secure general recognition as a most interesting subject of psychological study and a valuable addition to the resources of the physician4 ,but it was destined once more to be denied its rights by official science and to fall back into disrepute4 ,this was due to the coincidence about the year #ahdh of two events of some importance1 namely--the discovery of the anaesthetic properties of chloroform and the sudden rise of modern spiritualism4 ,the former afforded a very convenient substitute for the most obvious practical application of hypnotism1 the production of anaesthesia during surgical operations2 the latter involved it once more in a mass of fraud and superstition1 and1 for the popular mind1 drove it back to the region of the marvellous1 the supernatural and the dangerous1 made it1 in fact1 once more a branch of the black art4 ,from this time onward there took place a gradual differentiation of the animal magnetism of the #ahth century into two diverging branches1 hypnotism and spiritualism1 two branches which1 however1 are not yet entirely separated and1 perhaps1 never will be4 ,at the same time the original system of animal magnetism has lived on in an enfeebled condition and is now very nearly1 though not quite1 extinct4 ,in the development of hypnotism since the time of ,braid we may distinguish three lines1 the physiological1 the psychological and the pathological4 ,the last may be dismissed in a few words4 ,its principal representative was ,j4 ,m4 ,charcot1 who taught at the ,salptrire in ,paris that hypnosis is essentially a symptom of a morbid condition of hysteria or hystero-epilepsy4 ,this doctrine1 which1 owing to the great repute enjoyed by ,charcot1 has done much to retard the application of hypnotism1 is now completely discredited4 ,the workers of the physiological party attached special importance to the fixation of the eyes1 or to other forms of long continued and monotonous1 or violent1 sensory stimulation in the induction of hypnosis4 ,they believed that by acting on the senses in these ways they induced a peculiar condition of the nervous system1 which consisted in the temporary abolition of the cerebral functions and the consequent reduction of the subject to machine-like unconscious automatism4 ,the leading exponent of this view was ,r4 ,heidenhain1 professor of physiology at ,breslau1 whose experimental investigations played a large part in convincing the scientific world of the genuineness of the leading symptoms of hypnosis4 ,the purely psychological doctrine of hypnosis puts aside all physical and physiological influences and effects as of but little or no importance1 and seeks a psychological explanation of the induction of hypnosis and of all the phenomena4 ,this dates from #ahhd1 when ,h4 ,bernheim1 professor of medicine at ,nancy1 published his work ,de la ,suggestion 7republished in #ahhg with a second part on the therapeutics of hypnotism74 ,bernheim was led to the study of hypnotism by ,a4 ,a4 ,libeault1 who for twenty years had used it very largely and successfully in his general practice among the poor of ,nancy4 ,libeault rediscovered independently1 and ,bernheim made known to the world the truths1 twice previously discovered and twice lost sight of1 that expectation is a most important factor in the induction of hypnosis1 that increased suggestibility is its essential symptom1 and that in general the operator works upon his patient by mental influences4 ,although they went too far in the direction of ignoring the peculiarity of the state of the brain in hypnosis and the predisposing effect of monotonous sensory stimulation1 and in seeking to identify hypnosis with normal sleep1 the views of the ,nancy investigators have prevailed1 and are now in the main generally accepted4 ,their methods of verbal suggestion have been adopted by leading physicians in almost all civilized countries and have been proved to be efficacious in the relief of many disorders2 and as a method of psychological investigation hypnotism has proved1 especially in the hands of the late ,ed4 ,gurney1 of ,dr ,pierre ,janet and of other investigators1 capable of throwing much light on the constitution of the mind1 has opened up a number of problems of the deepest interest1 and has done more than any other of the many branches of modern psychology to show the limitations and comparative barrenness of the old psychology that relied on introspection alone and figured as a department of general philosophy4 ,in ,england1 always the last to enter into the general movement of the ,european mind1 the prejudice1 incredulity and ignorant misrepresentation with which hypnotism has everywhere been received have resisted its progress more stubbornly than elsewhere2 but even in ,england its reality and its value as a therapeutic agent have at last been officially recognized4 ,in #ahib1 just fifty years after ,braid clearly demonstrated the facts and published explanations of them almost identical with those now accepted1 a committee of the ,british ,medical ,association reported favourably upon hypnotism after a searching investigation2 it is now regularly employed by a number of physicians of high standing1 and the formation in #aijg of ,the ,medical ,society for the ,study of ,suggestive ,therapeutics shows that the footing it has gained is likely to be made good4 ,induction of ,hypnosis4--,it has now been abundantly proved that hypnosis can be induced in the great majority of normal persons1 provided that they willingly submit themselves to the process4 ,several of the most experienced operators have succeeded in hypnotizing more than #ij of the cases they have attempted1 and most of them are agreed that failure to induce hypnosis in any case is due either to lack of skill and tact on the part of the operator1 or to some unfavourable mental condition of the subject4 ,it has often been said that some races or peoples are by nature more readily hypnotizable than others2 of the ,french people especially this has been maintained4 ,but there is no sufficient ground for this statement4 ,the differences that undoubtedly obtain between populations of different regions in respect to the ease or difficulty with which a large proportion of all persons can be hypnotized are sufficiently explained by the differences of the attitude of the public towards hypnotism2 in ,france1 e4g41 and especially in ,nancy1 hypnotism has been made known to the public chiefly as a recognized auxiliary to the better known methods of medical treatment1 whereas in ,england the medical profession has allowed the public to make acquaintance with hypnotism through the medium of disgusting stage-performances whose only object was to raise a laugh1 and has1 with few exceptions1 joined in the general chorus of condemnation and mistrust4 ,hence in ,france patients submit themselves with confidence and goodwill to hypnotic treatment1 whereas in ,england it is still necessary in most cases to remove an ill-based prejudice before the treatment can be undertaken with hope of success4 ,for the confidence and goodwill of the patient are almost essential to success1 and even after hypnosis has been induced on several occasions a patient may be so influenced by injudicious friends that he cannot again be hypnotized or1 if hypnotized1 is much less amenable to the power of suggestion4 ,various methods of hypnotization are current1 but most practitioners combine the methods of ,braid and of ,bernheim4 ,after asking the patient to resign himself passively into their hands1 and after seating him in a comfortable arm-chair1 they direct him to fix his eyes upon some small object held generally in such a position that some slight muscular strain is involved in maintaining the fixation2 they then suggest to him verbally the idea or expectation of sleep and the sensations that normally accompany the oncoming of sleep1 the heaviness of the eyes1 the slackness of the limbs and so forth2 and when the eyes show signs of fatigue1 they either close them by gentle pressure or tell the subject to close them4 ,many also pass their hands slowly and regularly over the face1 with or without contact4 ,the old magnetizers attached great importance to such passes1 believing that by them the magnetic fluid was imparted to the patient2 but it seems clear that1 in so far as they contribute to induce hypnosis1 it is in their character merely of gentle1 monotonous1 sensory stimulations4 ,a well-disposed subject soon falls into a drowsy state and tends to pass into natural sleep2 but by speech1 by passes1 or by manipulating his limbs the operator keeps in touch with him1 keeps his waning attention open to the impressions he himself makes4 ,most subjects then find it difficult or impossible to open their eyes or to make any other movement which is forbidden or said to be impossible by the operator1 although they may be fully conscious of all that goes on about them and may have the conviction that if they did but make an effort they could break the spell4 ,this is a light stage of hypnosis beyond which some subjects can hardly be induced to pass and beyond which few pass at the first attempt4 ,but on successive occasions1 or even on the first occasion1 a favourable subject passes into deeper stages of hypnosis4 ,many attempts have been made to distinguish clearly marked and constantly occurring stages4 ,but it seems now clear that the complex of symptoms displayed varies in all cases with the idiosyncrasies of the subject and with the methods adopted by the operator4 ,in many subjects a waxy rigidity of the limbs appears spontaneously or can be induced by suggestion2 the limbs then retain for long periods without fatigue any position given them by the operator4 ,the most susceptible subjects pass into the stage known as artificial somnambulism4 ,in this condition they continue to respond to all suggestions made by the operator1 but seem as insensitive to all other impressions as a person in profound sleep or in coma2 and on awaking from this condition they are usually oblivious of all that they have heard1 said or done during the somnambulistic period4 ,when in this last condition patients are usually more profoundly influenced by suggestions1 especially post-hypnotic suggestions1 than when in the lighter stages2 but the lighter stages suffice for the production of many therapeutic effects4 ,when a patient is completely hypnotized1 his movements1 his senses1 his ideas and1 to some extent1 even the organic processes over which he has no voluntary control become more or less completely subject to the suggestions of the operator2 and usually he is responsive to the operator alone 7rapport7 unless he is instructed by the latter to respond also to the suggestions of other persons4 ,if left to himself the hypnotized subject will usually awake to his normal state after a period which is longer in proportion to the depth of hypnosis2 and the deeper stages seem to pass over into normal sleep4 ,the subject can in almost every case be brought quickly back to the normal state by the verbal command of the operator4 ,the ,principal ,effects produced by ,suggestion during ,hypnosis4--,the subject may not only be rendered incapable of contracting any of the muscles of the voluntary system1 but may also be made to use them with extraordinarily great or sustained force 7though by no means in all cases74 ,he can with difficulty refrain from performing any action commanded by the operator1 and usually carries out any simple command without hesitation4 ,any one of the sense-organs1 or any sensory region such as the skin or deep tissues of one limb may be rendered anaesthetic by verbal suggestion1 aided perhaps by some gentle manipulation of the part4 ,on this fact depends the surgical application of hypnotism4 ,sceptical observers are always inclined to doubt the genuineness of the anaesthesia produced by a mere word of command1 but the number of surgical operations performed under hypnotic anaesthesia suffices to put its reality beyond all question4 ,a convincing experiment may1 however1 be made on almost any good subject4 ,anaesthesia of one eye may be suggested and its reality tested in the following way4 ,anaesthesia of the left eye may be suggested1 and the subject be instructed to fix his gaze on a distant point and to give some signal as soon as he sees the operator's finger in the peripheral field of view4 ,the operator then brings his finger slowly from behind and to the right forwards towards the subject's line of sight4 ,the subject signals as soon as it crosses the normal temporal boundary of the field of view of the right eye4 ,the operator then brings his finger forward from a point behind and to the left of the subject's head4 ,the subject allows it to cross the monocular field of the left eye and signals only when the finger enters the field of vision of the right eye across its nasal boundary4 ,since few persons1 other than physiologists or medical men1 are aware of the relations of the boundaries of the monocular and binocular fields of vision1 the success of this experiment affords proof that the finger remains invisible to the subject during its passage across the monocular field of the left eye4 ,the abolition of pain1 especially of neuralgias1 the pain of rheumatic and other inflammations1 which is one of the most valuable applications of hypnotism1 is an effect closely allied to the production of such anaesthesia4 ,it has often been stated that in hypnosis the senses may be rendered extraordinarily acute or hyperaesthetic1 so that impressions too faint to affect the senses of the normal person may be perceived by the hypnotized subject2 but in view of the fact that most observers are ignorant of the normal limits of sensitivity and discrimination1 all such statements must be received with caution1 until we have more convincing evidence than has yet been brought forward4 ,positive and ,negative ,hallucinations are among the most striking effects of hypnotic suggestion4 ,a good subject may be made to experience an hallucinatory perception of almost any object1 the more easily the less unusual and out of harmony with the surroundings is the suggested object4 ,he may1 e4g41 be given a blank card and asked if he thinks it a good photograph of himself4 ,he may then assent and describe the photograph in some detail1 and1 what is more astonishing1 he may pick out the card as the one bearing the photograph1 after it has been mixed with other similar blank cards4 ,this seems to be due to the part played by points de repre1 insignificant details of surface or texture1 which serve as an objective basis around which the hallucinatory image is constructed by the pictorial imagination of the subject4 ,a negative hallucination may be induced by telling the subject that a certain object or person is no longer present1 when he ignores in every way that object or person4 ,this is more puzzling than the positive hallucination and will be referred to again in discussing the theory of hypnosis4 ,both kinds of hallucination tend to be systematically and logically developed2 if1 e4g41 the subject is told that a certain person is no longer visible1 he may become insensitive to impressions made on any sense by that person4 ,delusions1 or false beliefs as to their present situation or past experiences may be induced in many subjects4 ,on being assured that he is some other person1 or that he is in some strange situation1 the subject may accept the suggestion and adapt his behaviour with great histrionic skill to the induced delusion4 ,it is probable that many1 perhaps all1 subjects are vaguely aware1 as we sometimes are in dreams1 that the delusions and hallucinations they experience are of an unreal nature4 ,in the lighter stages of hypnosis a subject usually remembers the events of his waking life1 but in the deeper stages he is apt1 while remembering the events of previous hypnotic periods1 to be incapable of recalling his normal life2 but in this respect1 as also in respect to the extent to which on awaking he remembers the events of the hypnotic period1 the suggestions of the operator usually play a determining part4 ,among the organic changes that have been produced by hypnotic suggestion are slowing or acceleration of the cardiac and respiratory rhythms2 rise and fall of body-temperature through two or three degrees2 local erythema and even inflammation of the skin with vesication or exudation of small drops of blood2 evacuation of the bowel and vomiting2 modifications of the secretory activity of glands1 especially of the sweat-glands4 ,post-hypnotic ,effects4--,most subjects in whom any appreciable degree of hypnosis can be induced show some susceptibility to post-hypnotic suggestion1 i4e4 they may continue to be influenced1 when restored to the fully waking state1 by suggestions made during hypnosis1 more especially if the operator suggests that this shall be the case2 as a rule1 the deeper the stage of hypnosis reached1 the more effective are post-hypnotic suggestions4 ,the therapeutic applications of hypnotism depend in the main upon this post-hypnotic continuance of the working of suggestions4 ,if a subject is told that on awaking1 or on a certain signal1 or after the lapse of a given interval of time from the moment of awaking1 he will perform a certain action1 he usually feels some inclination to carry out the suggestion at the appropriate moment4 ,if he remembers that the action has been suggested to him he may refuse to perform it1 and if it is one repugnant to his moral nature1 or merely one that would make him appear ridiculous1 he may persist in his refusal4 ,but if the action is of a simple and ordinary nature he will usually perform it1 remarking that he cannot be comfortable till it is done4 ,if the subject was deeply hypnotized and remembers nothing of the hypnotic period1 he will carry out the post-hypnotic suggestion in almost every case1 no matter how complicated or absurd it may be1 so long as it is not one from which his normal self would be extremely averse2 and he will respond appropriately to the suggested signals1 although he is not conscious of their having been named2 he will often perform the action in a very natural way1 and will1 if questioned1 give some more or less adequate reason for it4 ,such actions1 determined by post-hypnotic suggestions of which no conscious memory remains1 may be carried out even after the lapse of many weeks or even months4 ,inhibitions of movement1 anaesthesia1 positive and negative hallucinations1 and delusions may also be made to persist for brief periods after the termination of hypnosis2 and organic effects1 such as the action of the bowels1 the oncoming of sleep and the cessation of pain1 may be determined by post-hypnotic suggestion4 ,in short1 it may be said that in a good subject all the kinds of suggestion which will take effect during hypnosis will also be effective if given as post-hypnotic suggestions4 ,theory of the ,hypnotic ,state4--,very many so called theories of hypnosis have been propounded1 but few of them demand serious consideration4 ,one author ascribes all the symptoms to cerebral anaemia1 another to cerebral congestion1 a third to temporary suppression of the functions of the cerebrum1 a fourth to abnormal cerebral excitability1 a fifth to the independent functioning of one hemisphere4 ,another seeks to explain all the facts by saying that in hypnosis our normal consciousness disappears and is replaced by a dream-consciousness2 and yet another by the assumption that every human organism comprises two mental selves or personalities1 a normal one and one which only comes into activity during sleep and hypnosis4 ,most of these theories would1 even if true1 carry us but a little way towards a complete understanding of the facts4 ,there is1 however1 one theory or principle of explanation which is now gradually taking shape under the hands of a number of the more penetrating workers in this field1 and which does seem to render intelligible many of the principle facts4 ,this is the theory of mental dissociation4 ,it is clear that a theory of hypnosis must attempt to give some account of the peculiar condition of the brain which is undoubtedly present as an essential feature of the state4 ,it is therefore not enough to say with ,bernheim that hypnosis is a state of abnormally increased suggestibility produced by suggestion2 nor is it enough1 though it is partially true1 to say that it is a state of mono-ideism or one of abnormally great concentration of attention4 ,any theory must be stated in terms of physiological psychology1 it must take account of both the psychical and the nervous peculiarities of the hypnotic state2 it must exhibit the physiological condition as in some degree similar to that obtaining in normal sleep2 but principally it must account for that abnormally great receptivity for ideas1 and that abnormally intense and effective operation of ideas so received1 which constitute abnormally great suggestibility4 ,the theory of mental dissociation may be stated in purely mental terms1 or primarily in terms of nervous structure and function1 and the latter mode of statement is probably the more profitable at the present time4 ,the increased effectiveness of ideas might be due to one of two conditions3 7#a7 it might be that certain tracts of the brain or the whole brain were in a condition of abnormally great excitability2 or 7#b7 an idea might operate more effectively in the mind and on the body1 not because it1 or the underlying brain-process was more intense than normally1 but because it worked out its effects free from the interference of contrary or irrelevant ideas that might weaken its force4 ,it is along this second line that the theory of mental dissociation attempts to explain the increased suggestibility of hypnosis4 ,to understand the theory we must bear in mind the nature of mental process in general and of its nervous concomitants4 ,mental process consists in the interplay1 not merely of ideas1 but rather of complex dispositions which are the more or less enduring conditions of the rise of ideas to consciousness4 ,each such disposition seems capable of remaining inactive or quiescent for long periods1 and of being excited in various degrees1 either by impressions made upon the sense-organs or by the spread of excitement from other dispositions4 ,when its excitement rises above a certain pitch of intensity1 the corresponding idea rises to the focus of consciousness4 ,these dispositions are essential factors of all mental process1 the essential conditions of all mental retention4 ,they may be called simply mental dispositions1 their nature being left undefined2 but for our present purpose it is advantageous to regard them as neural dispositions1 complex functional groups of nervous elements or neurones4 ,the neurones of each such group must be conceived as being so intimately connected with one another that the excitement of any part of the group at once spreads through the whole group or disposition1 so that it always functions as a unit4 ,the whole cerebrum must be conceived as consisting of a great number of such dispositions1 inextricably interwoven1 but interconnected in orderly fashion with very various degrees of intimacy2 groups of dispositions are very intimately connected to form neural systems1 so that the excitement of any one member of such a system tends to spread in succession to all the other members4 ,on the other hand1 it is a peculiarity of the reciprocal relations of all such dispositions and systems that the excitement of any one to such a degree that the corresponding idea rises to consciousness prevents or inhibits the excitement of others1 i4e4 all of them are in relations of reciprocal inhibition with one another 7see ,,muscle ,,and ,,nerve74 ,the excitement of dispositions associated together to form a system tends towards some end which1 either immediately or remotely1 is an action1 a bodily movement1 in many cases a movement of the organs of speech only4 ,now we know from many exact experiments that the neural dispositions act and react upon one another to some extent1 even when they are excited only in so feeble a degree that the corresponding ideas do not rise to consciousness4 ,in the normal state of the brain1 then1 when any idea is present to consciousness1 the corresponding neural disposition is in a state of dominant excitement1 but the intensity of that excitement is moderated1 depressed or partially inhibited by the sub-excitement of many rival or competing dispositions of other systems with which it is connected4 ,suppose now that all the nervous connexions between the multitudinous dispositions of the cerebrum are by some means rendered less effective1 that the association-paths are partially blocked or functionally depressed2 the result will be that1 while the most intimate connexions1 those between dispositions of any one system remain functional or permeable1 the weaker less intimate connexions1 those between dispositions belonging to different systems will be practically abolished for the time being2 each system of dispositions will then function more or less as an isolated system1 and its activity will no longer be subject to the depressing or inhibiting influence of other systems2 therefore each system1 on being excited in any way1 will tend to its end with more than normal force1 being freed from all interferences2 that is to say1 each idea or system of ideas will tend to work itself out and to realize itself in action immediately1 without suffering the opposition of antagonistic ideas which1 in the normal state of the brain1 might altogether prevent its realization in action4 ,the theory of mental dissociation assumes that the abnormal state of the brain that obtains during hypnosis is of this kind1 a temporary functional depression of all1 or of many of the associations or nervous links between the neural dispositions2 that is1 it regards hypnosis as a state of relative dissociation4 ,the lighter the stage of hypnosis the slighter is the degree of dissociation1 the deeper the stage the more nearly complete is the dissociation4 ,it is not essential that the theory should explain in what change this stage of dissociation consists1 but a view compatible with all that we know of the functions of the central nervous system may be suggested4 ,the connexions between neural dispositions involve synapses or cell-junctions1 and these seem to be the places of variable resistance which demarcate the dispositions and systems2 and there is good reason to think that their resistances vary with the state of the neurones which they connect1 being lowered when these are excited and raised when their excitement ebbs4 ,now1 in the waking state1 the varied stimuli1 which constantly rain upon all the sense-organs1 maintain the whole cerebrum in a state of sub-excitement1 keep all the cerebral neurones partially charged with free nervous energy4 ,when the subject lies down to sleep or submits himself to the hypnotizer he arrests as far as possible the flow of his thoughts1 and the sensory stimuli are diminished in number and intensity4 ,under these conditions the general cerebral activity tends to subside1 the free energy with which the cerebral neurones are charged ebbs away1 and the synaptic resistances rise proportionally2 then the effect of sensory impressions tends to be confined to the lower nervous level1 and the brain tends to come to rest4 ,if this takes place the condition of normal sleep is realized4 ,but in inducing hypnosis the operator1 by means of his words and manipulations1 keeps one system of ideas and the corresponding neural system in activity1 namely1 the ideas connected with himself2 thus he keeps open one channel of entry to the brain and mind1 and through this one open channel he can introduce whatever ideas he pleases2 and the ideas so introduced then operate with abnormally great effect because they work in a free field1 unchecked by rival ideas and tendencies4 ,this theory of relative dissociation has two great merits3 in the first place it goes far towards enabling us to understand in some degree most of the phenomena of hypnosis2 secondly1 we have good evidence that dissociation really occurs in deep hypnosis and in some allied states4 ,any one may readily work out for himself the application of the theory to the explanation of the power of the operator's suggestions to control movement1 to induce anaesthesia1 hallucinations and delusions1 and to exert on the organic processes an influence greater than can be exerted by mental processes in the normal state of the brain4 ,but the positive evidence of the occurrence of dissociation is a matter of great psychological interest and its nature must be briefly indicated4 ,the phenomena of automatic speech and writing afford the best evidence of cerebral dissociation4 ,many persons can1 while in an apparently normal or but very slightly abnormal condition1 produce automatic writing1 i4e4 intelligibly written sentences1 in some cases long connected passages1 of whose import they have no knowledge1 their self-conscious intelligence being continuously directed to some other task4 ,the carrying out of post-hypnotic suggestions affords in many cases similar evidence4 ,thus a subject may be told that after waking he will perform some action when a given signal1 such as a cough1 is repeated for the fifth time4 ,in the post-hypnotic state he remains unaware of his instructions1 is not conscious of noting the signals1 and yet carries out the suggestion at the fifth signal1 thereby proving that the signals have been in some sense noted and counted4 ,many interesting varieties of this experiment have been made1 some of much greater complexity2 but all agreeing in indicating that the suggested action is prepared for and determined by cerebral processes that do not affect the consciousness of the subject1 but seem to occur as a system of processes detached from the main stream of cerebral activity2 that is to say1 they imply the operation of relatively dissociated neural systems4 ,many authorities go further than this2 they argue that1 since actions of the kind described are determined by processes which involve operations1 such as counting1 that we are accustomed to regard as distinctly mental in character and that normally involve conscious activity1 we must believe that in these cases also consciousness or psychical activity is involved1 but that it remains as a separate system or stream of consciousness concurrent with the normal or personal consciousness4 ,in recent years the study of various abnormal mental states1 especially the investigations by ,french physicians of severe forms of hysteria1 have brought to light many facts which seem to justify this assumption of a secondary stream of consciousness1 a co- or sub-consciousness coexistent with the personal consciousness2 although1 from the nature of the case1 an absolute proof of such co-consciousness can hardly be obtained4 ,the co-consciousness seems to vary in degree of complexity and coherence from a mere succession of fragmentary sensations to an organized stream of mental activity1 which may rival in all respects the primary consciousness2 and in cases of the latter type it is usual to speak of the presence of a secondary personality4 ,the co-consciousness seems in the simpler cases1 e4g4 in cases of hysterical or hypnotic anaesthesia1 to consist of elements split off from the normal primary consciousness1 which remains correspondingly poorer2 and the assumption is usually made that such a stream of co-consciousness is the psychical correlate of groups and systems of neurones dissociated from the main mass of cerebral neurones4 ,if1 in spite of serious objections1 we entertain this conception1 we find that it helps us to give some account of various hypnotic phenomena that otherwise remain quite inexplicable2 some such conception seems to be required more particularly by the facts of negative hallucination and the execution of post-hypnotic suggestions involving such operations as counting and exact discrimination without primary consciousness4 ,supernormal ,hypnotic ,phenomena4--,the facts hitherto considered1 strange and perplexing as many of them are1 do not seem to demand for their explanation any principles of action fundamentally different from those operative in the normal human mind4 ,but much of the interest that has centred in hypnotism in recent years has been due to the fact that some of its manifestations seem to go beyond all such principles of explanation1 and to suggest the reality of modes of influence and action that science has not hitherto recognized4 ,of these by far the best attested are the post-hypnotic unconscious reckoning of time and telepathy or thought-transference 7for the latter see ,,telepathy74 ,the post-hypnotic reckoning and noting of the lapse of time seems in some instances to have been carried out1 in the absence of all extraneous aids and with complete unconsciousness on the part of the normal personality1 with such extreme precision that the achievement cannot be accounted for by any intensification of any faculty that we at present recognize or understand4 ,thus1 ,dr ,milne ,bramwell has reported the case of a patient who1 when commanded in hypnosis to perform some simple action after the lapse of many thousands of minutes1 would carry out the suggestion punctually to the minute1 without any means of knowing the exact time of day at which the suggestion was given or the time of day at the moment its performance fell due2 more recently a similar case1 even more striking in some respects1 has been carefully observed and described by ,dr ,t4 ,w4 ,mitchell4 ,other reported phenomena1 such as telaesthesia or clairvoyance1 and telekinesia1 are hardly sufficiently well attested to demand serious consideration in this place4 ,medical ,applications of ,hypnotism4--,the study and practice of hypnotism is not yet1 and probably never will be1 regarded as a normal part of the work of the general practitioner4 ,its successful application demands so much time1 tact1 and special experience1 that it will probably remain1 as it is now1 and as it is perhaps desirable that it should remain1 a specialized branch of medical practice4 ,in ,england it is only in recent years that it has been possible for a medical man to apply it in his practice without incurring professional odium and some risk of loss of reputation4 ,that1 in certain classes of cases1 it may effect a cure or bring relief when all other modes of treatment are of no avail is now rapidly becoming recognized2 but it is less generally recognized that it may be used with great advantage as a supplement to other modes of treatment in relieving symptoms that are accentuated by nervous irritability or mental disturbance4 ,a third wide field of usefulness lies before it in the cure of undesirable habits of many kinds4 ,under the first heading may be put insomnia1 neuralgia1 neurasthenia1 hysteria in almost all its many forms2 under the second1 inflammations such as that of chronic rheumatism1 contractures and paralyses resulting from gross lesion of the brain1 epilepsy1 dyspepsia1 menstrual irregularities1 sea-sickness2 under the third1 inebriety1 the morphia and other drug habits1 nail-biting1 enuresis nocturna1 masturbation1 constipation1 facial and other twitchings4 ,in pronounced mental diseases hypnotism seems to be almost useless2 for in general terms it may be said that it can be applied most effectively where the brain1 the instrument through which it works1 is sound and vigorous4 ,the widespread prejudice against the use of hypnotism is no doubt largely due to the marvellous and 7to most minds7 mysterious character of the effects producible by its means2 and this prejudice may be expected to diminish as our insight into the mode of its operation deepens4 ,the more purely bodily results achieved by hypnotic suggestion become in some degree intelligible if we regard it as a powerful means of diverting nervous energy from one channel or organ to others1 so as to give physiological rest to an overworked organ or tissue1 or so as to lead to the atrophy of one nervous habit and the replacement of it by a more desirable habit4 ,and in the cure of those disorders which involve a large mental element the essential part played by it is to drive out some habitually recurrent idea and to replace it by some idea1 expectation or conviction of healthy tendency4 ,it seems clear that the various systems of mind-curing in the hands of persons lacking all medical training1 which are now so frequently the cause of distressing and needless disasters1 owe their rapid spread to the fact that the medical profession has hitherto neglected to attach sufficient importance to the mental factor in the causation and cure of disease2 and it seems clear1 too1 that a more general and more intelligent appreciation of the possibilities of hypnotic treatment would constitute the best means at the disposal of the profession for combating this growing evil4 ,the ,dangers of ,hypnotism4--,much has been written on this head of late years1 and some of the enthusiastic advocates of hypnotic treatment have done harm to their cause by ignoring or denying in a too thoroughgoing manner the possibility of undesirable results of the spread of the knowledge and practice of hypnotism4 ,like all powerful agencies1 chloroform or morphia1 dynamite or strong electric currents1 hypnotic suggestion can only be safely used by those who have special knowledge and experience1 and1 like them1 it is liable to abuse4 ,there is little doubt that1 if a subject is repeatedly hypnotized and made to entertain all kinds of absurd delusions and to carry out very frequently post-hypnotic suggestions1 he may be liable to some ill-defined harm2 also1 that an unprincipled hypnotizer might secure an undue influence over a naturally weak subject4 ,but there is no ground for the belief that hypnotic treatment1 applied with good intentions and reasonable care and judgment1 does or can produce deleterious effects1 such as weakening of the will or liability to fall spontaneously into hypnosis4 ,all physicians of large experience in hypnotic practice are in agreement in respect to this point4 ,but some difference of opinion exists as to the possibility of deliberately inducing a subject to commit improper or criminal actions during hypnosis or by post-hypnotic suggestion4 ,there is1 however1 no doubt that subjects retain even in deep hypnosis a very considerable power of resistance to any suggestion that is repugnant to their moral nature2 and it has been shown that1 on some cases in which a subject in hypnosis is made to perform some ostensibly criminal action1 such as firing an unloaded pistol at a bystander or putting poison into a cup for him to drink1 he is aware1 however obscurely1 of the unreal nature of the situation4 ,nevertheless it must be admitted that a person lacking in moral sentiments might be induced to commit actions from which in the normal state he would abstain1 if only from fear of punishment2 and it is probable that a skilful and evil-intentioned operator could in some cases so deceive a well-disposed subject as to lead him into wrong-doing4 ,the proper precaution against such dangers is legislative regulation of the practice of hypnotism such as is already enforced in some countries4 ,,bibliography4--,the literature of hypnotism has increased in volume at a rapid rate during recent years4 ,of recent writings the following may be mentioned as among the most important3--,treatment by ,hypnotism and ,suggestion by ,c4 ,lloyd ,tuckey1 ,m4,d4 7#eth ed41 ,london1 #aijg72 ,hypnotism1 its ,history1 ,practice and ,theory1 by ,j4 ,milne ,bramwell1 ,m4,b4 7#bnd ed41 ,london1 #aijf72 ,hypnotism1 by ,albert ,moll 7#eth ed41 ,london1 #aija74 ,all these three books give good general accounts of hypnotism1 the first being the most strictly medical1 the last the most general in its treatment4 ,see also ,hypnotism3 or ,suggestion in ,psycho-,therapy1 by ,august ,forel 7translated from the #eth ,german ed4 by ,g4 ,h4 ,w4 ,armit1 ,london1 #aijf72 a number of papers by ,ed4 ,gurney1 and by ,ed4 ,gurney and ,f4 ,w4 ,h4 ,myers in ,proc4 of the ,soc4 for ,psychical ,research1 especially ,the ,stages of ,hypnotism1 in vol4 ii42 also some more recent papers in the same journal by other hands2 chapter on ,hypnotism in ,human ,personality and its ,survival of bodily ,death1 by ,f4 ,w4 ,h4 ,myers 7,london1 #aijc72 ,the ,psychology of ,suggestion1 by ,boris ,sidis1 ,ph4,d4 7,new ,york1 #ahih72 ,zur ,psychologie der ,suggestion1 by ,prof4 ,th4 ,lipp1 and other papers in the ,zeitschrift fr ,hypnotismus4 ,of special historical interest are the following3--tude sur le zoomagntisme1 par ,a4 ,a4 ,libeault 7,paris1 #ahhc72 ,hypnotisme1 suggestion1 psycho-thrapie1 par ,prof4 ,bernheim 7,paris1 #ahia72 ,braid on ,hypnotism 7a new issue of ,james ,braid's ,neurypnology71 edited by ,a4 ,e4 ,waite 7,london1 #ahii72 ,trait du somnambulisme1 by ,a4 ,bertrand 7,paris1 #ahbf74 ,a full bibliography is appended to ,dr ,milne ,bramwell's ,hypnotism4 7,w4 ,mc,d47 ,,hypocaust 7,gr4 ,greek3 hypokauston3 hypo1 beneath1 and ,greek3 kauein1 to burn71 the term given to the chamber formed under the floors of the ,roman baths1 through which the hot air from the furnace passed1 sometimes to a single flue1 as in the case of the tepidarium1 but in the calidarium and sweating-room to a series of flues placed side by side forming the lining of the walls4 ,the floor of the hot-air chamber consisted of tiles1 #b ft4 square1 laid on a bed of concrete2 on this a series of dwarf piers #b ft4 high were built of #h-;in4 square tiles placed about #af in4 apart1 which carried the floor of the hall or room2 this floor was formed of a bed of concrete covered with layers of pounded bricks and marble cement1 on which the marble pavement in slabs or tesserae was laid4 ,in colder countries1 as for instance in ,germany and ,england1 the living rooms were all heated in a similar way1 and round ,trves 7,trier7 both systems have been found in two or three ,roman villas1 with the one flue for the ordinary rooms and several wall flues for the hot baths4 ,in ,england these hypocausts are found in every ,roman settlement1 and the chief interest in these is centred in the magnificent mosaic pavements with which the principal rooms were laid4 ,many of the pavements found in ,london and elsewhere have been preserved in the ,british or the ,guildhall museums2 and in some of the provincial towns1 such as ,leicester and ,lincoln1 they remain in situ many feet below the present level of the town4 ,,hypochondriasis 7synonyms--the spleen1 the vapours71 a medical term 7from ,greek3 to hypochondrion1 ta hypochondria1 the soft part of the body immediately under the ,greek3 chondros or cartilage of the breast-bone7 given by the ancients1 and indeed by physicians down to the time of ,william ,cullen1 to diseases or derangements of one or more of the abdominal viscera4 ,cullen 7,clinical ,lectures1 #aggg7 classified it amongst nervous diseases1 and ,jean ,pierre ,falret 7#agid-ahgj7 more fully described it as a morbid condition of the nervous system characterized by depression of feeling and false beliefs as to an impaired state of the health4 ,the subjects of hypochondriasis are for the most part members of families in which hereditary predisposition to degradation of the nervous system is strong1 or those who have suffered from morbid influences affecting this system during the earlier years of life4 ,it may be dependent on depressing disease affecting the general system1 but under such circumstances it is generally so complicated with the symptoms of hysteria as to render differentiation difficult 7see ,,hysteria74 ,hypochondriasis is often handed down from one generation to another in its individual form1 but it is also not unfrequently to be met with in an individual as the sole manifestation in him of a family tendency to insanity4 ,in its most common form it is manifested by simple false belief as to the state of the health1 the intellect being otherwise unaffected4 ,we may instance the vapourish woman or the splenetic as terms society has applied to its milder manifestations4 ,such persons are constantly asserting a weak state of health although no palpable cause can be discovered4 ,in its more definite phases pain or uneasy sensations are referred by the patient to some particular region1 generally the abdomen1 the heart or the head4 ,that these are subjective is apparent from the fact that the general health is good3 all the functions of the various systems are duly performed2 the patient eats and sleeps well2 and1 when any circumstance temporarily overrides the false belief1 he is happy and comfortable4 ,no appeal to the reason is of any avail1 and the hypochondriac idea so dominates his existence as to render him unable to perform the ordinary duties of life4 ,in its most aggravated form hypochondriasis amounts to actual insanity1 delusions arising as to the existence of living creatures in the intestines or brain1 or to the effect that the body is materially changed2 e4g4 into glass1 wood1 c4 ,the symptoms of this condition may be remittent2 they may even disappear for years1 and only return on the advent of some exciting cause4 ,suicide is occasionally committed in order to escape from the constant misery4 ,recovery can only be looked for by placing the patient under such morally hygienic conditions as may help to turn his mind to other matters4 7,see also ,,neuropathology47 ,,hypocrisy1 pretence1 or false assumption of a high character1 especially in regard to religious belief or practice4 ,the ,greek ,greek3 hypokrisis1 from which the word is derived through the ,old ,french1 meant primarily the acting of a part on the stage1 from ,greek3 hypokrinesthai1 to give an answer1 to speak dialogue1 play a part on the stage1 hence to practice dissimulation4 ,,hypostasis1 in theology1 a term frequently occurring in the ,trinitarian controversies of the #dth and #eth centuries4 ,according to ,irenaeus 7i4 #e1 #d7 it was introduced into theology by ,gnostic writers1 and in earliest ecclesiastical usage appears1 as among the ,stoics1 to have been synonymous with ,greek3 ousia4 ,thus ,dionysius of ,rome 7cf4 ,routh1 ,rel4 ,sacr4 iii4 #cgc7 condemns the attempt to sever the ,godhead into three separate hypostases and three deities1 and the ,nicene ,creed in the anathemas speaks of ,greek3 ex heteras hypostases ousias4 ,alongside1 however1 of this persistent interchange there was a desire to distinguish between the terms1 and to confine ,greek3 hypostasis to the ,divine persons4 ,this tendency arose in ,alexandria1 and its progress may be seen in comparing the early and later writings of ,athanasius4 ,that writer1 in view of the ,arian trouble1 felt that it was better to speak of ,greek3 ousia as the common undifferentiated substance of ,deity1 and ,greek3 hypostasis as ,deity existing in a personal mode1 the substance of ,deity with certain special properties 7,greek3 ousia meta tinn idimatn74 ,at the council of ,alexandria in #cfb the phrase ,greek3 treis hypostaseis was permitted1 and the work of this council was supplemented by ,basil1 ,gregory of ,nazianzus and ,gregory of ,nyssa in the formula ,greek3 mia ousia1 treis hypostaseis or ,greek3 mia ousia en trisin hypostasesin4 ,the results arrived at by these ,cappadocian fathers were stated in a later age by ,john of ,damascus 7,de orth4 fid4 iii4 #f71 quoted in ,r4 ,l4 ,ottley1 ,the ,doctrine of the ,incarnation1 ii4 #beg4 ,,hypostyle1 in architecture1 the term applied to a hall1 the flat ceiling of which is supported by columns1 as in the ,hall of ,columns at ,karnak4 ,in this case the columns flanking the central avenue are of greater height than those of the side aisles1 and this admits of openings in the wall above the smaller columns1 through which light is admitted over the aisle roof1 through clerestory windows4 ,,hyposulphite ,,of ,,soda1 the name originally given to the substance known in chemistry as sodium thiosulphate1 ,na#b,s#b,o#c2 the earlier name is still commonly used1 especially by photographers1 who employ this chemical as a fixer4 ,in systematic chemistry1 sodium hyposulphite is a salt of hyposulphurous acid1 to which ,schutzenberger gave the formula ,h#b,,so#b1 but which ,bernthsen showed to be ,h#b,s#b,o#d4 7,see ,,sulphur47 ,,hypothec 7,lat4 hypotheca1 ,gr4 ,greek3 hypothk71 in ,roman law1 the most advanced form of the contract of pledge4 ,a specific thing may be given absolutely to a creditor on the understanding that it is to be given back when the creditor's debt is paid2 or the property in the thing may be assigned to the creditor while the debtor is allowed to remain in possession1 the creditor as owner being able to take possession if his debt is not discharged4 ,here we have the kind of security known as pledge and mortgage respectively4 ,in the hypotheca1 the property does not pass to the creditor1 nor does he get possession1 but he acquires a preferential right to have his debt paid out of the hypothecated property2 that is1 he can sell it and pay himself out of the proceeds1 or in default of a purchaser he can become the owner himself4 ,the name and the principle have passed into the law of ,scotland1 which distinguishes between conventional hypothecs1 as bottomry and respondentia1 and tacit hypothecs established by law4 ,of the latter the most important is the landlord's hypothec for rent 7corresponding to distress in the law of ,england71 which extends over the produce of the land and the cattle and sheep fed on it1 and over stock and horses used in husbandry4 ,the law of agricultural hypothec long caused much discontent in ,scotland2 its operation was restricted by the ,hypothec ,amendment 7,scotland7 ,act #ahfg1 and finally by the ,hypothec ,abolition 7,scotland7 ,act #ahhj it was enacted that the landlord's right of hypothec for the rent of land1 including the rent of any buildings thereon1 exceeding two acres in extent1 let for agriculture or pasture1 shall cease and determine4 ,by the same act and by the ,agricultural ,holdings 7,scotland7 ,act #ahhc other rights and remedies for rent1 where the right of hypothec had ceased1 were given to the landlord4 ,,hypothesis 7from ,gr4 ,greek3 hypotithenai1 to put under2 cf4 ,lat4 suppositio1 from sub-ponere71 in ordinary language1 an explanation1 supposition or assumption1 which is put forward in the absence of ascertained facts or causes4 ,both in ordinary life and in the acquisition of scientific knowledge hypothesis is all-important4 ,a detective's work consists largely in forming and testing hypothesis4 ,if an astronomer is confronted by some phenomenon which has no obvious explanation he may postulate some set of conditions which from his general knowledge of the subject would or might give rise to the phenomenon in question2 he then tests his hypothesis until he discovers whether it does or does not conflict with the facts4 ,an example of this process is that of the discovery of the planet ,neptune3 certain perturbations of the orbit of ,uranus had been observed1 and it was seen that these could be explained on the hypothesis of the existence of a then unknown planet1 and this hypothesis was verified by actual observation4 ,the progress of inductive knowledge is by the formation of successive hypotheses1 and it frequently happens that the demolition of one or even many hypotheses is the direct road to a new and accurate hypothesis1 i4e4 to fresh knowledge4 ,a hypothesis may1 therefore1 turn out to be entirely wrong1 yet it may be of the greatest practical use4 ,the recognition of the importance of hypotheses has led to various attempts at drawing up exact rules for their formation1 but logicians are generally agreed that only very elementary principles can be laid down4 ,thus a hypothesis must contain nothing which is at variance with known facts or principles3 it should not postulate conditions which cannot be verified empirically4 ,j4 ,s4 ,mill 7,logic ,,iii4 xiv4 #d7 laid down the principle that a hypothesis is not genuinely scientific if it is destined always to remain a hypothesis3 it must be of such a nature as to be either proved or disproved by comparison with observed facts3 in the same spirit ,bacon said that in searching for causes in nature ,deum semper excipimus4 ,mill's principle1 though sound in the abstract1 has1 except in a few cases1 little practical value in determining the admissibility of hypotheses1 and in practice any rule which tends to discourage hypothesis is in general undesirable4 ,the most satisfactory check on hypothesis is expert knowledge in the particular field of research by which rigorous tests may be applied4 ,this test is roughly of two kinds1 first by the ultimate principles or presuppositions on which a particular branch of knowledge rests1 and second by the comparison of correlative facts4 ,useful light is shed on this distinction by ,lotze1 who contrasts 7,logic1 #bgc7 postulates 7absolutely necessary assumptions without which the content of the observation with which we are dealing would contradict the laws of our thought7 with hypotheses1 which he defines as conjectures1 which seek to fill up the postulate thus abstractly stated by specifying the concrete causes1 forces or processes1 out of which the given phenomenon really arose in this particular case1 while in other cases maybe the same postulate is to be satisfied by utterly different though equivalent combinations of forces or active elements4 ,thus a hypothesis may be ruled out by principles or postulates without any reference to the concrete facts which belong to that division of the subject to explain which the hypothesis is formulated4 ,a true hypothesis1 therefore1 seeks not merely to connect or colligate two separate facts1 but to do this in the light of and subject to certain fundamental principles4 ,various attempts have been made to classify hypotheses and to distinguish hypothesis from a theory or a mere conjecture3 none of these have any great practical importance1 the differences being only in degree1 not in kind4 ,the adjective hypothetical is used1 in the same sense1 both loosely in contradistinction to real or actual1 and technically in the phrases hypothetical judgment and hypothetical syllogism4 7,see ,,logic and ,,syllogism47 ,see ,naville1 ,la ,logique de l'hypothse 7#ahhj71 and textbooks of logic1 e4g4 those of ,jevons1 ,bosanquet1 ,joseph2 ,liebmann1 ,der ,klimax d4 ,theorien4 ,,hypotrachelium 7,gr4 ,greek3 hypotrachlion1 the lower part of the neck1 ,greek3 trachlos71 in classical architecture1 the space between the annulet of the echinus and the upper bed of the shafts1 including1 according to ,c4 ,r4 ,cockerell1 the three grooves or sinkings found in some of the older examples1 as in the temple of ,neptune at ,paestum and the temple of ,aphaea at ,aegina2 there being only one groove in the ,parthenon1 the ,theseum and later examples4 ,in the temple of ,ceres and the so-called ,basilica at ,paestum the hypotrachelium consists of a concave sinking carved with vertical lines suggestive of leaves1 the tops of which project forward4 ,a similar decoration is found in the capital of the columns flanking the tomb of ,agamemnon at ,mycenae1 but here the hypotrachelium projects forward with a cavetto moulding1 and is carved with triple leaves like the buds of a rose4 ,in the ,roman ,doric ,order the term was sometimes applied to that which is generally known as the necking1 the space between the fillet and the annulet4 ,,hypsometer 7,gr4 ,greek3 hypsos1 height1 ,greek3 metron1 a measure71 an instrument for measuring heights which employs the principles that the boiling-point of a liquid is lowered by diminishing the pressure1 and that the barometric pressure varies with the height of the point of observation4 ,the instrument consists of a cylindrical vessel in which the liquid1 usually water1 is boiled1 surmounted by a jacketed column1 in the outer partitions of which the vapour circulates1 while in the central one a thermometer is placed4 ,to deduce the height of the station from the observed boiling-point1 it is necessary to know the relation existing between the boiling-point and pressure1 and also between the pressure and height of the atmosphere4 ,,hyracoidea1 a suborder of ungulate mammals represented at the present day only by the ,syrian hyrax 7,procavia syriaca71 the coney of the ,bible1 and its numerous ,african relatives1 all of which may be included in the single genus ,procavia 7or ,hyrax71 and consequently in the family ,procaviidae4 ,these creatures have no proper ,english name1 and are generally known as hyraxes1 from the scientific term 7,hyrax7 by which they were for many years designated--a term which has unfortunately had to give place to the earlier ,procavia4 ,in size these animals may be compared roughly to rabbits and hares2 and they have rodent-like habits1 hunching up their backs after the fashion of some foreign members of the hare-family1 more especially the ,liu-,kiu rabbit4 ,in the matter of nomenclature these animals have been singularly unfortunate4 ,in the title hyrax they have1 for instance1 usurped the ,greek name for the shrew-mouse2 while in the ,bible they have been given the old ,english name for the rabbit4 ,perhaps rock-rabbit would be the best name4 ,at the ,cape they are known to the ,dutch as dass 7badger71 which has been anglicized into dassie4 ,illustration3 ,,fig4 #a4--,the ,cape ,hyrax 7,procavia capensis74 ,as regards the recent forms1 the dentition in the fully adult animal consists only of incisors and cheek-teeth1 the formula being i4 1 c4 #j_/j1 p4 #d_/d m4 #c_/c4 ,there is1 however1 a minute upper canine developed at first1 which is early shed2 and in extinct forms this tooth was functional and molar-like4 ,the upper incisors have persistent pulps1 and are curved longitudinally1 forming a semicircle as in rodents2 they are1 however1 not flattened from before backwards as in that order1 but prismatic1 with an antero-external1 an antero-internal and a posterior surface1 the first two only being covered with enamel2 their tips are consequently not chisel-shaped1 but sharp-pointed4 ,they are preceded by functional1 rooted milk-teeth4 ,the lower incisors have long tapering roots1 but not of persistent growth2 and are straight1 directed somewhat forwards1 with awl-shaped1 tri-lobed crowns4 ,behind the incisors is a considerable gap1 followed by the cheek-teeth1 which are all contiguous1 and formed almost exactly on the pattern of some of the perissodactyle ungulates4 ,the milk-dentition includes three pairs of incisors and one of canines in each jaw4 ,the hyoid arch is unlike that of any known mammal4 ,the dorsal and lumbar vertebrae are very numerous1 #bh to #cj1 of which #ba or #bb bear ribs4 ,the tail is extremely short4 ,there are no clavicles4 ,in the fore foot1 the three middle toes are subequally developed1 the fifth is present1 but smaller1 and the first is rudimentary1 although1 in one species at least1 all its normal bones are present4 ,the terminal phalanges of the four outer digits are small1 somewhat conical and flattened in form4 ,the carpus has a distinct os centrale4 ,there is a slight ridge on the femur in the place of a third trochanter4 ,the fibula is complete1 thickest at its upper end1 where it generally unites with the tibia4 ,the articulation between the tibia and astragalus is more complex than in other mammals1 the end of the malleolus entering into it4 ,the hind-foot is very like that of a rhinoceros1 having three well-developed toes4 ,there is no trace of a first toe1 and the fifth meta-tarsal is represented by a small nodule4 ,the terminal phalange of the inner 7or second7 digit is deeply cleft1 and has a peculiar long curved claw1 the others having short broad nails4 ,the stomach is formed upon much the same principle as that of the horse or rhinoceros1 but is more elongated transversely and divided by a constriction into two cavities--a large left cul de sac1 lined by a very dense white epithelium1 and a right pyloric cavity1 with a thick1 soft1 vascular lining4 ,the intestinal canal is long1 and has1 in addition to the ordinary short1 but capacious and sacculated caecum at the commencement of the colon1 lower down1 a pair of large1 conical1 pointed caeca4 ,the liver is much subdivided1 and there is no gall-bladder4 ,the brain resembles that of typical ungulates far more than that of rodents4 ,the testes are permanently abdominal4 ,the ureters open into the fundus of the bladder as in some ,rodents4 ,the female has six teats1 of which four are inguinal and two axillary1 and the placenta is zonary and deciduous4 ,there is a gland on the back4 ,illustration3 ,,fig4 #b4--,skull and ,dentition of ,tree-,hyrax 7,procavia dorsalis74 ,the more typical members of the genus are terrestrial in their habits1 and their cheek-teeth have nearly the same pattern as in rhinoceroses2 while the interval between the upper incisors is less than the width of the teeth2 and the lower incisors are only slightly notched at the cutting edge4 ,vertebrae3 ,c4 #g1 ,d4 #bb1 ,l4 #h1 ,s4 #f1 ,c4 #f4 ,of this form the earliest known species1 ,p4 capensis1 is the type2 but there are many other species1 as ,p4 syriaca1 and ,p4 brucei from ,syria and eastern ,africa4 ,they inhabit mountainous and rocky regions1 and live on the ground4 ,in a second section the molar teeth have the same pattern as in ,palaeotherium 7except that the third lower molar has but two lobes72 the interval between the upper incisors exceeds the width of the teeth2 and the lower incisors have distinctly tri-lobed crowns4 ,vertebrae3 ,c4 #g1 ,d4 #ba1 ,l4 #g1 ,s4 #e1 ,c4 #aj4 ,the members of this section frequent the trunks and large branches of trees1 sleeping in holes4 ,there are several species from ,western and ,south ,africa1 as ,p4 arboreus and ,p4 dorsalis4 ,the members of both groups appear to have a power like that possessed by geckos of clinging to vertical surfaces of rocks and trees by the soles of their feet4 ,extinct ,hyracoids4--,for many years extinct representatives of the ,hyracoidea were unknown1 partly owing to the fact that certain fossils were not recognized as really belonging to that group4 ,the longest known of these was originally named ,leptodon graecus1 but1 on account of the preoccupation of the generic title1 the designation has been changed to ,pliohyrax graecus4 ,this animal1 whose remains occur in the ,lower ,pliocene of both ,attica and ,samos1 was about the size of a donkey1 and possessed three pairs of upper incisor teeth1 of which the innermost were large and trihedral1 recalling those of the existing genus4 ,on the other hand1 the two outer pairs of incisors were in contact with one another and with the canines1 so as to form on each side a series continuous with the cheek-teeth4 ,the next representatives of the group occur in the ,upper ,eocene beds of the ,fayum district of ,egypt1 where the genera ,saghatherium and ,megalohyrax occur4 ,these are regarded as representing a distinct family1 the ,saghatheriidae1 characterized by the possession of the full series of twenty-two teeth in the upper jaw1 among which the first pair of incisors was modified to form trihedral rootless tusks1 while the two remaining pairs were separated from one another and from the teeth in front by gaps4 ,the canine was like a premolar1 and in contact with the first tooth of that series2 and the cheek-teeth were short-crowned1 with the premolar simpler than the molars1 and a third lobe to the last lower tooth of the latter series4 ,the members of this genus were small or medium-sized ungulates with single-rooted incisors4 ,on the other hand1 the representatives of the contemporary genus ,megalohyrax were approximately as large as ,pliohyrax1 and in some instances had double roots to the second and third incisors4 ,it is now possible to define the suborder ,hyracoidea as including ungulates with a centrale in the carpus1 plantigrade feet1 in which the first and fifth toes are reduced in greater or less degree1 and clavicles and a foramen in the lower end of the humerus are absent4 ,the femur has a small third trochanter1 the radius and ulna and tibia and fibula are respectively separate1 at least in the young1 and the fibula articulates with the astragalus4 ,the earlier forms had the full series of #dd teeth1 with the premolars simpler than the molars2 but in the later types the canines and some of the incisors disappear1 and at least the hinder premolars become molar-like4 ,in all cases the first upper incisors are large and rootless4 ,that the group originated in ,africa there can be no reasonable doubt2 and it is remarkable that so early as the ,upper ,eocene the types in existence differed comparatively little in structure from the modern forms4 ,in fact the hyraxes were then almost as distinct from other mammals as they are at the present day4 ,see also ,c4 ,w4 ,andrews1 ,descriptive ,catalogue of the ,tertiary ,vertebrata of the ,fayum1 ,british ,museum 7#aijf74 7,r4 ,l4997 ,,hyrcania4 7#a7 ,an ancient district of ,asia1 south of the ,caspian ,sea1 and bounded on the ,e4 by the river ,oxus1 called ,virkana1 or ,wolf's ,land1 in ,old ,persian4 ,it was a wide and indefinite tract4 ,its chief city is called ,tape by ,strabo1 ,zadracarta by ,arrian 7probably the modern ,astarabad74 ,the latter is evidently the same as ,carta1 mentioned by ,strabo as an important city4 ,little is known of the history of the country4 ,xenophon says it was subdued by the ,assyrians2 ,curtius that #fjjj ,hyrcanians were in the army of ,darius ,,iii4 7#b7 ,two towns named ,hyrcania are mentioned1 one in ,hyrcania1 the other in ,lydia4 ,the latter is said to have derived its name from a colony of ,hyrcanians1 transported thither by the ,persians4 ,,hyrcanus 7,greek3 ,hykanos71 a ,greek surname1 of unknown origin1 borne by several ,jews of the ,maccabaean period4 ,,john ,,hyrcanus ,i41 high priest of the ,jews from #ace to #aje ,b4,c41 was the youngest son of ,simon ,maccabaeus4 ,in #acg ,b4,c4 he1 along with his brother ,judas1 commanded the force which repelled the invasion of ,judaea led by ,cendebeus1 the general of ,antiochus ,,vii4 ,sidetes4 ,on the assassination of his father and two elder brothers by ,ptolemy1 governor of ,jericho1 his brother-in-law1 in ,february #ace1 he succeeded to the high priesthood and the supreme authority in ,judaea4 ,while still engaged in the struggle with ,ptolemy1 he was attacked by ,antiochus with a large army 7#acd71 and compelled to shut himself up in ,jerusalem2 after a severe siege peace was at last secured only on condition of a ,jewish disarmament1 and the payment of an indemnity and an annual tribute1 for which hostages were taken4 ,in #abi he accompanied ,antiochus as a vassal prince on his ill-fated ,parthian expedition2 returning1 however1 to ,judaea before winter1 he escaped the final disaster4 ,by the judicious mission of an embassy to ,rome he now obtained confirmation of the alliance which his father had previously made with the growing western power2 at the same time he availed himself of the weakened state of the ,syrian monarchy under ,demetrius ,,ii4 to overrun ,samaria1 and also to invade ,idumaea1 which he completely subdued1 compelling its inhabitants to receive circumcision and accept the ,jewish faith4 ,after a long period of rest he directed his arms against the town of ,samaria1 which1 in spite of the intervention of ,antiochus1 his sons ,antigonus and ,aristobulus ultimately took1 and by his orders razed to the ground 7c4 #ajj ,b4,c474 ,he died in #aje1 and was succeeded by ,aristobulus1 the eldest of his five sons4 ,the external policy of ,hyrcanus was marked by considerable energy and tact1 and1 aided as it was by favouring circumstances1 was so successful as to leave the ,jewish nation in a position of independence and of influence such as it had not known since the days of ,solomon4 ,during its later years his reign was much disturbed1 however1 by the contentions for ascendancy which arose between the ,pharisees and ,sadducees1 the two rival sects or parties which then for the first time 7under those names at least7 came into prominence4 ,josephus has related the curious circumstances under which he ultimately transferred his personal support from the former to the latter4 ,,john ,,hyrcanus ,,ii41 high priest from #gh to #dj ,b4,c41 was the eldest son of ,alexander ,jannaeus by his wife ,alexandra1 and was thus a grandson of the preceding4 ,when his father died in #gh1 he was by his mother forthwith appointed high priest1 and on her death in #fi he claimed the succession to the supreme civil authority also2 but1 after a brief and troubled reign of three months1 he was compelled to abdicate both kingly and priestly dignities in favour of his more energetic and ambitious younger brother ,aristobulus ,,ii4 ,in #fc it suited the policy of ,pompey that he should be restored to the high priesthood1 with some semblance of supreme command1 but of much of this semblance even he was soon again deprived by the arrangement of the pro-consul ,gabinius1 according to which ,palestine was in #eg ,b4,c4 divided into five separate circles 7,greek3 synodoi1 synedria74 ,for services rendered to ,caesar after the battle of ,pharsalia1 he was again rewarded with the sovereignty 7,greek3 prostasia tou ethnous1 ,jos4 ,ant4 xx4 #aj7 in #dg ,b4,c41 ,antipater of ,idumaea1 however1 being at the same time made procurator of ,judaea4 ,in #da ,b4,c4 he was practically superseded by ,antony's appointment of ,herod and ,phasael to be tetrarchs of ,judaea2 and in the following year he was taken prisoner by the ,parthians1 deprived of his ears that he might be permanently disqualified for priestly office1 and carried to ,babylon4 ,he was permitted in #cc ,b4,c4 to return to ,jerusalem1 where on a charge of treasonable correspondence with ,malchus1 king of ,arabia1 he was put to death in #cj ,b4,c4 ,see ,josephus 7,ant4 xiii4 #h-aj2 xiv4 #e-ac2 ,bell4 ,jud4 i4 #b2 i4 #h-ac74 ,also ,,maccabees1 ,history4 7,j4 ,h4 ,a4 ,h47 ,,hyssop 7,hyssopus officinalis71 a garden herb belonging to the natural order ,labiatae1 formerly cultivated for use in domestic medicine4 ,it is a small perennial plant about #b ft4 high1 with slender1 quadrangular1 woody stems2 narrowly elliptical1 pointed1 entire1 dotted leaves1 about #a in4 long and #a_/c in4 wide1 growing in pairs on the stem2 and long terminal1 erect1 half-whorled1 leafy spikes of small violet-blue flowers1 which are in blossom from ,june to ,september4 ,varieties of the plant occur in gardens with red and white flowers1 also one having variegated leaves4 ,the leaves have a warm1 aromatic1 bitter taste1 and are believed to owe their properties to a volatile oil which is present in the proportion of to 4 ,hyssop is a native of the south of ,europe1 its range extending eastward to central ,asia4 ,a strong tea made of the leaves1 and sweetened with honey1 was formerly used in pulmonary and catarrhal affections1 and externally as an application to bruises and indolent swellings4 ,the hedge hyssop 7,gratiola officinalis7 belongs to the natural order ,scrophulariaceae1 and is a native of marshy lands in the south of ,europe1 whence it was introduced into ,britain more than #cjj years ago4 ,like ,hyssopus officinalis1 it has smooth opposite entire leaves1 but the stems are cylindrical1 the leaves twice the size1 and the flowers solitary in the axils of the leaves and having a yellowish-red veined tube and bluish-white limb1 while the capsules are oval and many-seeded4 ,the herb has a bitter1 nauseous taste1 but is almost odourless4 ,in small quantities it acts as a purgative1 diuretic and emetic when taken internally4 ,it was formerly official in the ,edinburgh ,pharmacopoeia1 being esteemed as a remedy for dropsy4 ,it is said to have formed the basis of a celebrated nostrum for gout1 called ,eau mdicinale1 and in former times was called ,gratia ,dei4 ,when growing in abundance1 as it does in some damp pastures in ,switzerland1 it becomes dangerous to cattle4 ,g4 peruviana is known to possess similar properties4 ,the hyssop 7'ezob7 of ,scripture 7,ex4 xii4 #bb2 ,lev4 xiv4 #d1 #f2 ,numb4 xix4 #f1 #ah2 #a ,kings v4 #ac 7iv4 #cc72 ,ps4 li4 #i 7#g72 ,john xix4 #bi71 a wall-growing plant adapted for sprinkling purposes1 has long been the subject of learned disputation1 the only point on which all have agreed being that it is not to be identified with the ,hyssopus officinalis1 which is not a native of ,palestine4 ,no fewer than eighteen plants have been supposed by various authors to answer the conditions1 and ,celsius has devoted more than forty pages to the discussion of their several claims4 ,by ,tristram 7,oxford ,bible for ,teachers1 #ahhj7 and others the caper plant 7,capparis spinosa7 is supposed to be meant2 but1 apart from other difficulties1 this identification is open to the objection that the caper seems to be1 at least in one passage 7,eccl4 xii4 #e71 otherwise designated 7'abiy-ynah74 ,thenius 7on #a ,kings v4 #ac7 suggests ,orthotrichum saxatile4 ,the most probable opinion would seem to be that found in ,maimonides and many later writers1 according to which the ,hebrew 'ezob is to be identified with the ,arabic sa'atar1 now understood to be ,satureja ,thymus1 a plant of very frequent occurrence in ,syria and ,palestine1 with which ,thymus ,serpyllum1 or wild thyme1 and ,satureja ,thymbra are closely allied4 ,its smell1 taste and medicinal properties are similar to those of ,h4 officinalis4 ,in ,morocco the sa'atar of the ,arabs is ,origanum compactum2 and it appears probable that several plants of the genera ,thymus1 ,origanum and others nearly allied in form and habit1 and found in similar localities1 were used under the name of hyssop4 ,,hystaspes 7the ,greek form of the ,persian ,vishtaspa74 7#a7 ,a semi-legendary king 7kava71 praised by ,zoroaster as his protector and a true believer1 son of ,aurvataspa 7,lohrasp74 ,the later tradition and the ,shahname of ,firdousi makes him 7in the modern form ,kai ,gushtasp7 king of ,iran4 ,as ,zoroaster probably preached his religion in eastern ,iran1 ,vishtaspa must have been a dynast in ,bactria or ,sogdiana4 ,the ,zoroastrian religion was already dominant in ,media in the time of the ,assyrian king ,sargon 7c4 #gae ,b4,c471 and had been propagated here probably in much earlier times 7cf4 ,,persia72 the time of ,zoroaster and ,vishtaspa may therefore be put at c4 #ajjj ,b4,c4 7#b7 ,a ,persian1 father of ,darius ,i41 under whose reign he was governor of ,parthia1 as ,darius himself mentions in the ,behistun inscription 7#b4 #fe74 ,by ,ammianus ,marcellinus1 xxiii4 #f4 #cb1 and by many modern authors he has been identified with the protector of ,zoroaster1 which is equally impossible for chronological and historical reasons1 and from the evidence of the development of ,zoroastrianism itself 7see ,,persia3 ,ancient ,history74 7,ed4 ,m47 ,,hysteresis 7,gr4 ,greek3 hystersis1 from ,greek3 hysterein1 to lag behind71 a term added to the vocabulary of physical science by ,j4 ,a4 ,ewing1 who defines it as follows3 ,when there are two qualities ,m and ,n such that cyclic variations of ,n cause cyclic variations of ,m1 then if the changes of ,m lag behind those of ,n1 we may say that there is hysteresis in the relation of ,m to ,n 7,phil4 ,trans41 #ahhe1 #agf1 p4 #ebd74 ,the phenomenon is best known in connexion with magnetism4 ,if an iron bar is subjected to a magnetic force which is first gradually increased to a maximum and then gradually diminished1 the resulting magnetization of the bar for any given value of the magnetic force will be greater when the force is decreasing than when it is increasing2 the iron always tends to retain the magnetic condition which it has previously acquired1 and changes of its magnetization consequently lag behind changes of the magnetic force4 ,thus there is hysteresis in the relation of magnetization to magnetic force4 ,in consequence of hysteresis the process of magnetizing a piece of iron to a certain intensity and then restoring it to its original condition1 or of effecting a double reversal of its magnetization1 involves the expenditure of energy1 which is dissipated as heat in the iron4 ,electrical generators and transformers often contain pieces of iron the magnetization of which is reversed many times in a second1 and in order to economize power and to avoid undue heating it is essential that hysteresis should in such cases be as small as possible4 ,iron and mild steels showing remarkably little hysteresis are now specially manufactured for use in the construction of electrical machinery4 7,see ,,magnetism47 ,,hysteria1 a term applied to an affection which may manifest itself by a variety of symptoms1 and which depends upon a disordered condition of the highest nervous centres4 ,it is characterized by psychical peculiarities1 while in addition there is often derangement of the functions subserved by the lower cerebral and spinal centres4 ,histological examination of the nervous system has failed to disclose associated structural alterations4 ,by the ancients and by modern physicians down to the time of ,sydenham the symptoms of hysteria were supposed to be directly due to disturbances of the uterus 7,gr4 ,greek3 hystera1 whence the name74 ,this view is now universally recognized to be erroneous4 ,the term functional is often used by ,english neurologists as synonymous with hysterical1 a nomenclature which is tentatively advantageous since it is at least non-committal4 ,p4 ,j4 ,mbius has defined hysteria as a state in which ideas control the body and produce morbid changes in its functions4 ,p4 ,janet1 who has done much to popularize the psychical origin of the affection1 holds that there is a limitation of the field of consciousness comparable to the contraction of the visual fields met with in the disease4 ,the hysterical subject1 according to this view1 is incapable of taking into the field of consciousness all the impressions of which the normal individual is conscious4 ,strong momentary impressions are no longer controlled so efficiently because of the defective simultaneous impressions of previous memories4 ,hence the readiness with which the impulse of the moment is obeyed1 the loss of emotional control and the increased susceptibility to external suggestion1 which are so characteristic4 ,a secondary subconscious mental state is engendered by the relegation of less prominent impressions to a lower sphere4 ,the dual personality which is typically exemplified in somnambulism and in the hypnotic state is thus induced4 ,the explanation of hysterical symptoms which are independent of the will1 and of the existence of which the individual may be unaware1 is to be found in a relative preponderance of this secondary subconscious state as compared with the primary conscious personality4 ,an elaboration of this theory affords an explanation of hysterical symptoms dependent upon a fixed idea4 ,the following definition of hysteria has recently been advanced by ,j4 ,f4 ,f4 ,babinski3 ,hysteria is a psychical condition manifesting itself principally by signs that may be termed primary1 and in an accessory sense others that we may call secondary4 ,the characteristic of the primary signs is that they may be exactly reproduced in certain subjects by suggestion and dispelled by persuasion4 ,the characteristic of the secondary signs is that they are closely related to the primary phenomena4 ,the causes of hysteria may be divided into 7a7 the predisposing1 such as hereditary predisposition to nervous disease1 sex1 age and national idiosyncrasy2 and 7b7 the immediate1 such as mental and physical exhaustion1 fright and other emotional influences1 pregnancy1 the puerperal condition1 diseases of the uterus and its appendages1 and the depressing influence of injury or general disease4 ,perhaps1 taken over all1 hereditary predisposition to nerve-instability may be asserted as the most prolific cause4 ,there is frequently direct inheritance1 and cases of epilepsy and insanity or other form of nervous disease are rarely wanting when the family history is carefully enquired into4 ,as regards age1 the condition is apt to appear at the evolution periods of life--puberty1 pregnancy and the climacteric--without any further assignable cause except that first spoken of4 ,it is rare in young children1 but very frequent in girls between the ages of fifteen and twenty-five1 while it sometimes manifests itself in women at the menopause4 ,it is much more common in the female than in the male--in the proportion of #bj to #a4 ,certain races are more liable to the disease than others2 thus the ,latin races are much more prone to hysteria than are those who come of a ,teutonic stock1 and in more aggravated and complex forms4 ,in ,england it has been asserted that an undue proportion of cases occur among ,jews4 ,occupation1 or be it rather said want of occupation1 is a prolific cause4 ,this is noticeable more especially in the higher classes of society4 ,an hysterical attack may occur as an immediate sequel to an epileptic fit4 ,if the patient suffers only from petit mal 7see ,,epilepsy71 unaccompanied by true epileptic fits1 the significance of the hysterical seizure1 which is really a post-epileptic phenomenon1 may remain unrecognized4 ,it is convenient to group the very varied symptoms of hysteria into paroxysmal and chronic4 ,the popular term hysterics is applied to an explosion of emotionalism1 generally the result of mental excitement1 on which convulsive fits may supervene4 ,the characters of these vary1 and may closely resemble epilepsy4 ,the hysterical fit is generally preceded by an aura or warning4 ,this sometimes takes the form of a sensation as of a lump in the throat 7globus hystericus74 ,the patient may fall1 but very rarely is injured in so doing4 ,the eyes are often tightly closed1 the body and limbs become rigid1 and the back may become so arched that the patient rests on her heels and head 7opisthotonos74 ,this stage is usually followed by violent struggling movements4 ,there is no loss of consciousness4 ,the attack may last for half-an-hour or even longer4 ,hysterical fits in their fully-developed form are rarely seen in ,england1 though common in ,france4 ,in the chronic condition we find an extraordinary complexity of symptoms1 both physical and mental4 ,the physical symptoms are extremely diverse4 ,there may be a paralysis of one or more limbs associated with rigidity1 which may persist for weeks1 months or years4 ,in some cases1 the patient is unable to walk2 in others there are peculiarities of the gait quite unlike anything met with in organic disease4 ,perversions of sensation are usually present2 a common instance is the sensation of a nail being driven through the vertex of the head 7clavus hystericus74 ,the region of the spine is a very frequent seat of hysterical pain4 ,loss of sensation 7anaesthesia71 of which the patient may be unaware1 is of common occurrence4 ,very often this sensory loss is limited exactly to one-half of the body1 including the leg1 arm and face on that side 7hemianaesthesia74 ,sensation to touch1 pain1 heat and cold1 and electrical stimuli may have completely disappeared in the anaesthetic region4 ,in other cases1 the anaesthesia is relative or it may be partial1 certain forms of sensation remaining intact4 ,anaesthesia is almost always accompanied by an inability to recognize the exact position of the affected limb when the eyes are closed4 ,when hemianaesthesia is present1 sight1 hearing1 taste and smell are usually impaired on that side of the body4 ,often there is loss of voice 7hysterical aphonia74 ,it is to such cases of hysterical paralysis and sensory disturbance that the wonderful cures effected by quacks and charlatans may be referred4 ,the mental symptoms have not the same tendency to pass away suddenly4 ,they may be spoken of as inter-paroxysmal and paroxysmal4 ,the chief characteristics of the former are extreme emotionalism combined with obstructiveness1 a desire to be an object of interest and a constant craving for sympathy which is often procured at an immense sacrifice of personal comfort4 ,obstructiveness is the invariable symptom4 ,hysteria may pass into absolute insanity4 ,the treatment of hysteria demands great tact and firmness on the part of the physician4 ,the affection is a definite entity and has to be clearly distinguished from malingering1 with which it is so often erroneously regarded as synonymous4 ,drugs are of little value4 ,the moral treatment is all-important4 ,in severe cases1 removal from home surroundings and isolation1 either in a hospital ward or nursing home1 are essential1 in order that full benefit may be derived from psychotherapeutic measures4 ,,bibliography4--,charcot1 ,leons sur les maladies du systme nerveuse 7#ahgg72 ,s4 ,weir ,mitchell1 ,lectures on ,diseases of the ,nervous ,system especially in ,women 7#ahhe72 ,buzzard1 ,simulation of ,hysteria by ,organic ,nervous ,disease 7#ahia72 ,pitres1 ,leons cliniques sur l'hystrie et l'hypnotisme 7#ahia72 ,richer1 tudes cliniques sur la grande hystrie 7#ahia72 ,gilles de la ,tourette1 ,trait clinique et thrapeutique de l'hystrie 7#ahia72 ,bastian1 ,hysterical or ,functional ,paralysis 7#ahic72 ,ormerod1 ,art4 ,hysteria1 in ,clifford ,allbutt's ,system of ,medicine 7#ahii72 ,camus and ,pagnez1 ,isolement et ,psychotherapie 7#aijd74 7,j4 ,b4 ,t42 ,e4 ,bra47 ,,hysteron-,,proteron 7,gr4 ,greek3 hysteron1 latter1 and ,greek3 proteron1 former71 a figure of speech1 in which the order of words or phrases is inverted1 and that which should logically or naturally come last is put first1 to secure emphasis for the principal idea2 the classical example is ,virgil's moriamur et in media arma ruamus1 let us die and charge into the thick of the fight 7,aen4 ii4 #ceh74 ,the term is also applied to any inversion in order of events1 arguments1 c4 ,,hythe1 a market town and watering-place1 one of the ,cinque ,ports1 and a municipal and parliamentary borough of ,kent1 ,england1 #fg m4 ,s4,e4 by ,e4 of ,london on a branch of the ,south ,eastern ,chatham railway4 ,pop4 7#aija7 #eeeg4 ,it is beautifully situated at the foot of a steep hill near the eastern extremity of ,romney ,marsh1 about half a mile from the sea1 and consists principally of one long street running parallel with the shore1 with which it is connected by a straight avenue of wych elms4 ,on account of its fine situation and picturesque and interesting neighbourhood1 it is a favourite watering-place4 ,a sea-wall and parade extend eastward to ,sandgate1 a distance of #c m4 ,there is communication with ,sandgate by means of a tramway along the front4 ,on the slope of the hill above the town stands the fine church of ,st ,leonard1 partly ,late ,norman1 with a very beautiful ,early ,english chancel4 ,the tower was rebuilt about #agej4 ,in a vault under the chancel there is a collection of human skulls and bones supposed to be the remains of men killed in a battle near ,hythe in #def4 ,lionel ,lukin 7#agdb-ahcd71 inventor of the life-boat1 is buried in the churchyard4 ,hythe possesses a guildhall founded in #agid and two hospitals1 that of ,st ,bartholomew founded by ,haimo1 bishop of ,rochester1 in #accf1 and that of ,st ,john 7rebuilt in #ahjb71 of still greater antiquity but unknown date1 founded originally for the reception of lepers4 ,a government school of musketry1 in which instructors for the army are trained1 was established in #ahed1 and has been extended since1 and the ,shorncliffe military camp is within #b m4 of the town4 ,lympne1 which is now #c m4 inland1 is thought to have been the original harbour which gave ,hythe a place among the ,cinque ,ports4 ,the course of the ancient estuary may be distinctly traced from here along the road to ,hythe1 the sea-sand lying on the surface and colouring the soil4 ,here are remains of a ,roman fortress1 and excavations have brought to light many remains of the ,roman ,portus ,lemanis4 ,large portions of the fortress walls are standing4 ,at the south-west corner is one of the circular towers which occurred along the line of wall4 ,the site is now occupied by the fine old castellated mansion of ,studfall castle1 formerly a residence of the archdeacons of ,canterbury4 ,the name denotes a fallen place1 and is not infrequently thus applied to ancient remains4 ,the church at ,lympne is ,early ,english1 with a ,norman tower built by ,archbishop ,lanfranc1 and ,roman material may be traced in the walls4 ,a short distance east is ,shipway or ,shepway ,cross1 where some of the great assemblies relating to the ,cinque ,ports were held4 ,a mile north from ,hythe is ,saltwood ,castle1 of very ancient origin1 but rebuilt in the time of ,richard ,,ii4 ,the castle was granted to the see of ,canterbury in #ajbf1 but escheated to the crown in the time of ,henry ,,ii41 when the murder of ,thomas ,beckett is said to have been concerted here1 and having been restored to the archbishops by ,king ,john remained a residence of theirs until the time of ,henry ,,viii4 ,it was restored as a residence in #ahhb4 ,about #b m4 ,n4,w4 of ,saltwood are remains of the fortified #adth-century manor-house of ,westenhanger4 ,it is quadrangular and surrounded by a moat1 and of the nine towers 7alternately square and round7 by which the walls were defended1 three remain4 ,the parliamentary borough of ,hythe1 which includes ,folkestone1 ,sandgate and a number of neighbouring villages1 returns one member4 ,the town is governed by a mayor1 #d aldermen and #ab councillors4 ,area #bfag acres4 ,hythe 7,heda1 ,heya1 ,hethe1 ,hithe1 i4e4 landing-place7 was known as a port in ,saxon times1 and was granted by ,halfden1 a ,saxon thegn1 to ,christ ,church1 ,canterbury4 ,in the ,domesday ,survey the borough is entered among the archbishop's lands as appurtenant to his manor of ,saltwood1 and the bailiff of the town was appointed by the archbishop4 ,hythe was evidently a ,cinque ,port before the ,conquest1 as ,king ,john in #abje confirmed the liberties1 viz4 freedom from toll1 the right to be impleaded only at the ,shepway court1 c41 which the townsmen had under ,edward the ,confessor4 ,the liberties of the ,cinque ,ports were confirmed in ,magna ,carta and later by ,edward ,i4 in a general charter1 which was confirmed1 often with additions1 by subsequent kings down to ,james ,,ii4 ,john's charter to ,hythe was confirmed by ,henry ,,iv41 ,henry ,v4 and ,henry ,,vi4 ,these charters were granted to the ,cinque ,ports in return for the fifty-seven ships which they supplied for the royal service1 of which five were contributed by ,hythe4 ,the ports were first represented in the parliament of #acfe1 to which they each sent four members4 ,hythe was governed by twelve jurats until #aegd1 when it was incorporated by ,elizabeth under the title of the mayor1 jurats and commonalty of ,hythe2 a fair for the sale of fish1 c41 was also granted1 to be held on the feast of ,st ,peter and ,st ,paul4 ,as the sea gradually retreated from ,hythe and the harbour became choked up with sand1 the town suffered the fate of other places near it1 and lost its old importance4 ,i the ninth letter of the ,english and ,latin alphabet1 the tenth in the ,greek and ,phoenician1 because in these the symbol ,teth 7the ,greek theta7 preceded it4 ,teth was not included in the ,latin alphabet because that language had no sound corresponding to the ,greek theta1 but the symbol was metamorphosed and utilized as the numeral ,c #ajj1 which took this form through the influence of the initial letter of the ,latin centum4 ,the name of ,i in the ,phoenician alphabet was ,yod4 ,though in form it seems the simplest of letters it was originally much more complex4 ,in ,phoenician it takes the form symbol1 which is found also in the earliest ,syriac and ,palestinian inscriptions with little modification4 ,ultimately in ,hebrew it became reduced to a very small symbol1 whence comes its use as a term of contempt for things of no importance as in not one jot or tittle 7,matthew v4 #ah74 ,the name passed from ,phoenician to ,greek1 and thence to the ,latin of the vulgate as iota1 and from the ,latin the ,english word is derived4 ,amongst the ,greeks of ,asia it appears only as the simple upright ,i1 but in some of the oldest alphabets elsewhere1 as ,crete1 ,thera1 ,attica1 ,achaia and its colonies in lower ,italy1 it takes the form symbol or ,s1 while at ,corinth and ,corcyra it appears first in a form closely resembling the later ,greek sigma ,sigma4 ,it had originally no cross-stroke at top and bottom4 ,i being not i but z4 ,the ,phoenician alphabet having no vowel symbols1 the value of yod was that of the ,english y4 ,in ,greek1 where the consonant sound had disappeared or been converted into h1 ,i is regularly used as a vowel4 ,occasionally1 as in ,pamphylian1 it is used dialectically as a glide between i and another vowel1 as in the proper name ,greek3 ,damatriius4 ,in ,latin ,i was used alike for both vowel and consonant1 as in iugum 7yoke74 ,the sound represented by it was approximately that still assigned to i on the continent4 ,neither ,greek nor ,latin made any distinction in writing between short and long i1 though in the ,latin of the ,empire the long sound was occasionally represented by a longer form of the symbol ,i4 ,the dot over the i begins in the #eth or #fth century ,a4,d4 ,in pronunciation the ,english short i is a more open sound than that of most languages1 and does not correspond to the ,greek and ,latin sound4 ,nor are the ,english short and long i of the same quality4 ,the short i in ,sweet's terminology is a high-front-wide vowel1 the long i1 in ,english often spelt ee in words like seed1 is diphthonged1 beginning like the short vowel but becoming higher as it proceeds4 ,the ,latin short i1 however1 in final syllables was open and ultimately became e1 e4g4 in the neuter of i-stems as utile from utili-s4 ,medially both the short and the long sounds are very common in syllables which were originally unaccented1 because in such positions many other sounds passed into i3 officio but facio1 redimo but emo1 quidlibet but lubet 7libet is later72 collido but laedo1 fido from an older feido1 istis 7dative plural7 from an earlier istois4 7,p4 ,gi47 ,,iambic1 the term employed in prosody to denote a succession of verses1 each consisting of a foot or metre called an iambus 7,greek3 iambos71 formed of two syllables1 of which the first is short and the second long 7u --74 ,after the dactylic hexameter1 the iambic trimeter was the most popular metre of ancient ,greece4 ,archilochus is said to have been the inventor of this iambic verse1 the ,greek3 trimetros consisting of three iambic fed4 ,in the ,greek tragedians an iambic line is formed of six feet arranged in obedience to the following scheme3-- u -- u -- u -- u -- u -- u -- u u u u u u u u u u u u u u u -- -- -- -- -- -- -- u u -- u u u u -- ,much of the beauty of the verse depends on the caesura1 which is usually ,in the middle of the third foot1 and far less frequently in the middle of the fourth4 ,the ,english language runs more naturally in the iambic metre than in any other4 ,the normal blank verse in ,english is founded upon an iambic basis1 and ,milton's line-- ,and swims or sinks or wades or creeps or flies -- exhibits it in its primitive form4 ,the ordinary alexandrine of ,french literature is a hexapod iambic1 but in all questions of quantity in modern prosody great care has to be exercised to recollect that all ascriptions of classic names to modern forms of rhymed or blank verse are merely approximate4 ,the octosyllabic1 or four-foot iambic metre1 has found great favour in ,english verse founded on old romances4 ,decasyllabic iambic lines rhyming together form an heroic metre4 ,,iamblichus 7d4 c4 ,a4,d4 #ccj71 the chief representative of ,syrian ,neoplatonism1 is only imperfectly known to us in the events of his life and the details of his creed4 ,we learn1 however1 from ,suidas1 and from his biographer ,eunapius1 that he was born at ,chalcis in ,coele-,syria1 the scion of a rich and illustrious family1 that he studied under ,anatolius and afterwards under ,porphyry1 the pupil of ,plotinus1 that he himself gathered together a large number of disciples of different nations with whom he lived on terms of genial friendship1 that he wrote various philosophical books1 and that he died during the reign of ,constantine1--according to ,fabricius1 before ,a4,d4 #ccc4 ,his residence 7probably7 at his native town of ,chalcis was varied by a yearly visit with his pupils to the baths of ,gadara4 ,of the books referred to by ,suidas only a fraction has been preserved4 ,his commentaries on ,plato and ,aristotle1 and works on the ,chaldaean theology and on the soul1 are lost4 ,for our knowledge of his system we are indebted partly to the fragments of these writings preserved by ,stobaeus and others1 and to the notices of his successors1 especially ,proclus1 partly to his five extant books1 the sections of a great work on the ,pythagorean philosophy4 ,besides these1 ,proclus 7#dab-dhe7 seems to have ascribed to him#a the authorship of the celebrated book ,on the ,egyptian ,mysteries 7so-called71 and although its differences in style and in some points of doctrine from the writings just mentioned make it improbable that the work was by ,iamblichus himself1 it certainly emanated from his school1 and in its systematic attempt to give a speculative justification of the polytheistic cultus of the day1 marks the turning-point in the history of thought at which ,iamblichus stood4 ,as a speculative theory ,neoplatonism 7q4v47 had received its highest development from ,plotinus4 ,the modifications introduced by ,iamblichus were the elaboration in greater detail of its formal divisions1 the more systematic application of the ,pythagorean number-symbolism1 and chiefly1 under the influence of ,oriental systems1 the thorough-going mythic interpretation of what the previous philosophy had still regarded as notional4 ,it is on the last account1 probably1 that ,iamblichus was looked upon with such extravagant veneration4 ,as a philosopher he had learning indeed1 but little originality4 ,his aim was to give a philosophical rendering of the popular religion4 ,by his contemporaries he was accredited with miraculous powers 7which he1 however1 disclaimed71 and by his followers in the decline of ,greek philosophy1 and his admirers on its revival in the #aeth and #afth centuries1 his name was scarcely mentioned without the epithet divine or most divine1 while1 not content with the more modest eulogy of ,eunapius that he was inferior to ,porphyry only in style1 the emperor ,julian regarded him as not even second to ,plato1 and said that he would give all the gold of ,lydia for one epistle of ,iamblichus4 ,theoretically1 the philosophy of ,plotinus was an attempt to harmonize the principles of the various ,greek schools4 ,at the head of his system he placed the transcendent incommunicable one 7,greek3 hen amethekton71 whose first-begotten is intellect 7,greek3 nous71 from which proceeds soul 7,greek3 psych71 which in turn gives birth to ,greek3 physis1 the realm of nature4 ,immediately after the absolute one1 ,iamblichus introduced a second superexistent unity to stand between it and the many as the producer of intellect1 and made the three succeeding moments of the development 7intellect1 soul and nature7 undergo various modifications4 ,he speaks of them as intellectual 7,greek3 theoi noeroi71 supramundane 7,greek3 hyperkosmioi71 and mundane gods 7,greek3 egkosmioi74 ,the first of these--which ,plotinus represented under the three stages of 7objective7 being 7,greek3 on71 7subjective7 life 7,greek3 z71 and 7realized7 intellect 7,greek3 nous7--is distinguished by him into spheres of intelligible gods 7,greek3 theoi notoi7 and of intellectual gods 7,greek3 theoi noeroi71 each subdivided into triads1 the latter sphere being the place of ideas1 the former of the archetypes of these ideas4 ,between these two worlds1 at once separating and uniting them1 some scholars think there was inserted by ,iamblichus1 as afterwards by ,proclus1 a third sphere partaking of the nature of both 7,greek3 theoi notoi kai noeroi74 ,but this supposition depends on a merely conjectural emendation of the text4 ,we read1 however1 that in the intellectual hebdomad he assigned the third rank among the fathers to the ,demiurge4 ,the ,demiurge1 ,zeus1 or world-creating potency1 is thus identified with the perfected ,greek3 nous1 the intellectual triad being increased to a hebdomad1 probably 7as ,zeller supposes7 through the subdivision of its first two members4 ,as in ,plotinus ,greek3 nous produced nature by mediation of ,greek3 psych1 so here the intelligible gods are followed by a triad of psychic gods4 ,the first of these is incommunicable and supramundane1 while the other two seem to be mundane though rational4 ,in the third class1 or mundane gods 7,greek3 theoi egkosmioi71 there is a still greater wealth of divinities1 of various local position1 function1 and rank4 ,we read of gods1 angels1 demons and heroes1 of twelve heavenly gods whose number is increased to thirty-six or three hundred and sixty1 and of seventy-two other gods proceeding from them1 of twenty-one chiefs 7,greek3 hegemones7 and forty-two nature-gods 7,greek3 theoi genesiourgoi71 besides guardian divinities1 of particular individuals and nations4 ,the world is thus peopled by a crowd of superhuman beings influencing natural events1 possessing and communicating knowledge of the future1 and not inaccessible to prayers and offerings4 ,the whole of this complex theory is ruled by a mathematical formulism of triad1 hebdomad1 c41 while the first principle is identified with the monad1 ,greek3 nous with the dyad1 and ,greek3 psych with the triad1 symbolic meanings being also assigned to the other numbers4 ,the theorems of mathematics1 he says1 apply absolutely to all things1 from things divine to original matter 7,greek3 hyl74 ,but though he thus subjects all things to number1 he holds elsewhere that numbers are independent existences1 and occupy a middle place between the limited and unlimited4 ,another difficulty of the system is the account given of nature4 ,it is said to be bound by the indissoluble chains of necessity which men call fate1 as distinguished from divine things which are not subject to fate4 ,yet1 being itself the result of higher powers becoming corporeal1 a continual stream of elevating influence flows from them to it1 interfering with its necessary laws and turning to good ends the imperfect and evil4 ,of evil no satisfactory account is given2 it is said to have been generated accidentally4 ,in his doctrine of man ,iamblichus retains for the soul the middle place between intellect and nature which it occupies in the universal order4 ,he rejects the passionless and purely intellectual character ascribed to the human soul by ,plotinus1 distinguishing it sharply both from those above and those below it4 ,he maintains that it moves between the higher and lower spheres1 that it descends by a necessary law 7not solely for trial or punishment7 into the body1 and1 passing perhaps from one human body to another1 returns again to the supersensible4 ,this return is effected by the virtuous activities which the soul performs through its own power of free will1 and by the assistance of the gods4 ,these virtues were classified by ,porphyry as political1 purifying 7,greek3 kathartikai71 theoretical1 and paradigmatic2 and to these ,iamblichus adds a fifth class of priestly virtues 7,greek3 hieratikai aretai71 in which the divinest part of the soul raises itself above intellect to absolute being4 ,iamblichus does not seem ever to have attained to that ecstatic communion with and absorption in deity which was the aim of earlier ,neoplatonism1 and which ,plotinus enjoyed four times in his life1 ,porphyry once4 ,indeed his tendency was not so much to raise man to ,god as to bring the gods down to men--a tendency shown still more plainly in the ,answer of ,abamon the master to ,porphyry's letter to ,anebo and solutions of the doubts therein expressed1 afterwards entitled the ,liber de mysteriis1 and ascribed to ,iamblichus4 ,in answer to questions raised and doubts expressed by ,porphyry1 the writer of this treatise appeals to the innate idea all men have of the gods as testifying to the existence of divinities countless in number and various in rank 7to the correct arrangement of which he1 like ,iamblichus1 attaches the greatest importance74 ,he holds with the latter that above all principles of being and intelligence stands the absolute one1 from whom the first god and king spontaneously proceeds2 while after these follow the ethereal1 empyrean1 and heavenly gods1 and the various orders of archangels1 angels1 demons1 and heroes distinguished in nature1 power1 and activity1 and in greater profusion than even the imagination of ,iamblichus had conceived4 ,he says that all the gods are good 7though he in another place admits the existence of evil demons who must be propitiated71 and traces the source of evil to matter2 rebuts the objection that their answering prayer implies passivity on the part of gods or demons2 defends divination1 soothsaying1 and theurgic practices as manifestations of the divine activity2 describes the appearances of the different sorts of divinities2 discusses the various kinds of sacrifice1 which he says must be suitable to the different natures of the gods1 material and immaterial1 and to the double condition of the sacrificer as bound to the body or free from it 7differing thus in his psychology from ,iamblichus72 and1 in conclusion1 states that the only way to happiness is through knowledge of and union with the gods1 and that theurgic practices alone prepare the mind for this union--again going beyond his master1 who held assiduous contemplation of divine things to be sufficient4 ,it is the passionless nature of the soul which permits it to be thus united to divine beings1--knowledge of this mystic union and of the worship associated with it having been derived from the ,egyptian priests1 who learnt it from ,hermes4 ,on one point only does the author of the ,de mysteriis seem not to go so far as ,iamblichus in thus making philosophy subservient to priestcraft4 ,he condemns as folly and impiety the worship of images of the gods1 though his master held that these simulacra were filled with divine power1 whether made by the hand of man or 7as he believed7 fallen from heaven4 ,but images could easily be dispensed with from the point of view of the writer1 who not only held that all things were full of gods 7,greek3 panta plr then1 as ,thales said71 but thought that each man had a special divinity of his own--an ,greek3 idios daimn--as his guard and companion4 ,the following are the extant works of ,iamblichus3 7#a7 ,on the ,pythagorean 7,life ,greek3 ,peri tou ,pythagorikou biou71 ed4 ,t4 ,kiessling 7#ahae71 ,a4 ,nauck 7,st ,petersburg1 #ahhd72 for a discussion of the authorities used see ,e4 ,rohde in ,rheinisches ,museum1 xxvi41 xxvii4 7#ahga1 #ahgb72 ,eng4 trans4 by ,thomas ,taylor 7#ahah71 7#b7 ,the ,exhortation to ,philosophy 7,greek3 ,logos protreptikos eis philosophian71 ed4 ,t4 ,kiessling 7#ahac72 ,h4 ,piselli 7#ahhh74 7#c7 ,the treatise ,on the ,general ,science of ,mathematics 7,greek3 ,peri ts koins mathmatks epistms71 ed4 ,j4 ,g4 ,friis 7,copenhagen1 #agij71 ,n4 ,festa 7,leipzig1 #ahia74 7#d7 ,the book ,on the ,arithmetic of ,nicomachus 7,greek3 ,peri ts ,nikomachou arithmtiks eisaggs71 along with fragments on fate 7,greek3 ,peri heimarmens7 and prayer 7,greek3 ,peri euchs71 ed4 ,s4 ,tennulius 7#afhh71 the ,arithmetic by ,h4 ,pistelli 7#ahid74 7#e7 ,the ,theological ,principles of ,arithmetic 7,greek3 ,theologoumena ts arithmtiks7--the seventh book of the series--by ,f4 ,ast 7,leipzig1 #ahag74 ,two lost books1 treating of the physical and ethical signification of numbers1 stood fifth and sixth1 while books on music1 geometry and astronomy followed4 ,the emperor ,julian had a great admiration for ,iamblichus1 whom he considered intellectually not inferior to ,plato2 but the ,letters to ,iamblicus the ,philosopher which bear his name are now generally considered spurious4 ,the so-called ,liber de mysteriis was first edited1 with ,latin translation and notes1 by ,t4 ,gale 7,oxford1 #afgh71 and more recently by ,c4 ,parthey 7,berlin1 #aheg72 ,eng4 trans4 by ,thomas ,taylor 7#ahba74 ,there is a monograph on ,iamblichus by ,g4 ,e4 ,hebenstreit 7,de ,iamblichi1 philosophi ,syri1 doctrina1 ,leipzig1 #agfd71 and one of the ,de myst4 by ,harless 7,das ,buch v4 d4 gypt4 ,myst41 ,munich1 #aheh74 ,the best accounts of ,iamblichus are those of ,zeller1 ,phil4 d4 ,griechen1 iii4 #b1 pp4 #fac sq41 #bnd ed42 ,e4 ,vacherot1 ,hist4 de l'cole d',alexandrie 7#ahdf71 ii4 #eg sq42 ,j4 ,simon1 ,hist4 de l'cole d',alexandrie 7#ahde72 ,a4 ,e4 ,chaignet1 ,histoire de la psychologie des ,grecs 7,paris1 #ahic7 v4 #fg-ajh2 ,t4 ,whittaker1 ,the ,neo-,platonists 7,cambridge1 #aija74 7,w4 ,r4 ,so47 ,,footnote3 #a ,besides the anonymous testimony prefixed to an ancient ,,ms4 of ,proclus1 ,de ,myst4 viii4 #c seems to be quoted by the latter as ,iamblichus's4 ,cf4 ,meiners4 ,judicium de libro qui de ,myst4 ,aeg4 inscribitur1 in ,comment4 ,soc4 ,reg4 ,sci4 ,gott41 vol4 iv41 #agha1 p4 #gg4 ,,iamblichus1 of ,syria1 the earliest of the ,greek romance writers1 flourished in the #bnd century ,a4,d4 ,he was the author of ,greek3 ,babylniaka1 the loves of ,rhodanes and ,sinonis1 of which an epitome is preserved in ,photius 7cod4 #id74 ,garmus1 a legendary king of ,babylon1 forces ,sinonis to marry him and throws ,rhodanes into prison4 ,the lovers manage to escape1 and after many singular adventures1 in which magic plays a considerable part1 ,garmus is overthrown by ,rhodanes1 who becomes king of ,babylon4 ,according to ,suidas1 ,iamblichus was a freedman1 and a scholiast's note on ,photius further informs us that he was a native ,syrian 7not descended from ,greek settlers72 that he borrowed the material for his romance from a love story told him by his ,babylonian tutor1 and that he subsequently applied himself with great success to the study of ,greek4 ,a ,,ms4 of the original in the library of the ,escorial is said to have been destroyed by fire in #afgj4 ,only a few fragments have been preserved1 in addition to ,photius's epitome4 ,see ,scriptores erotici1 ed4 ,a4 ,hirschig 7#ahef7 and ,r4 ,hercher 7#aheh72 ,a4 ,mai1 ,scriptorum veterum nova collectio1 ii42 ,e4 ,rohde1 ,der griechische ,roman 7#aijj74 ,,iannina 7i4e4 the city of ,st ,john2 ,gr4 ,ioannina2 ,turk ,yani2 also written ,janina1 ,jannina1 and1 according to its ,albanian pronunciation1 ,yanina71 the capital of the vilayet of ,iannina1 ,albania1 ,european ,turkey4 ,pop4 7#aije7 about #bb1jjj4 ,the largest ethnical groups in the population are the ,albanian and ,greek2 the purest form of colloquial ,greek is spoken here among the wealthy and highly educated merchant families4 ,the position of ,iannina is strikingly picturesque4 ,at the foot of the grey limestone mass of ,mount ,mitzekeli 7#aejj ft471 which forms part of the fine range of hills running north from the ,gulf of ,arta1 there lies a valley 7the ,hellopia of antiquity7 partly occupied by a lake2 and the city is built on the slopes of a slight eminence1 stretching down to the western shore4 ,it has greatly declined from the state of barbaric prosperity which it enjoyed from #aghh to #ahbb1 when it was the seat of ,ali ,pasha 7q4v471 and was estimated to have from #cj1jjj to #ej1jjj inhabitants4 ,the fortress--,demir ,kule or ,iron ,castle1 which1 like the principal seraglio1 was built on a promontory jutting into the lake--is now in ruins4 ,but the city is the seat of a ,greek archbishop1 and still possesses many mosques and churches1 besides synagogues1 a ,greek college 7gymnasium71 a library and a hospital4 ,sayades 7opposite ,corfu7 and ,arta are the places through which it receives its imports4 ,the rich gold and silver embroidery for which the city has long been famous is still one of the notable articles in its bazaar2 but the commercial importance of ,iannina has notably declined since the cession of ,arta and ,thessaly to ,greece in #ahha4 ,iannina had previously been one of the chief centres of the ,thessalian grain trade2 it now exports little except cheese1 hides1 bitumen and sheepskins to the annual value of about #abj1jjj2 the imports1 which supply only the local demand for provisions1 textile goods1 hardware1 c41 are worth about double that sum4 ,the lake of ,iannina 7perhaps to be identified with the ,pambotus or ,pambotis of antiquity7 is #f m4 long1 and has an area of #bd sq4m41 with an extreme depth of less than #ce ft4 ,in time of flood it is united with the smaller lake of ,labchistas to the north4 ,there are no affluents of any considerable size1 and the only outlets are underground passages or katavothra extending for many miles through the calcareous rocks4 ,the theory supported by ,w4 ,m4 ,leake 7,northern ,greece1 ,london1 #ahce7 that the citadel of ,iannina is to be identified with ,dodona1 is now generally abandoned in favour of the claims of a more southern site4 ,as ,anna ,comnena1 in describing the capture of the town 7,greek3 ta ,ioannina7 by ,bohemond in #ajhb1 speaks of the walls as being dilapidated1 it may be supposed that the place existed before the #aath century4 ,it is mentioned from time to time in the ,byzantine annals1 and on the establishment of the lordship of ,epirus by ,michael ,angelus ,comnenus ,ducas1 it became his capital4 ,in the middle ages it was successively attacked by ,serbs1 ,macedonians and ,albanians2 but it was in possession of the successors of ,michael when the forces of the ,sultan ,murad appeared before it in #adcj 7cf4 ,hahn1 ,alban4 ,studien1 ,jena #ahed1 pp4 #cai-cbb74 ,since #adca it has continued under ,turkish rule4 ,descriptions of ,iannina will be found in ,holland's ,travels 7#ahae72 ,hughes1 ,travels in ,greece1 c4 7#ahcj72 ,h4 ,f4 ,tozer1 ,researches in the ,highlands of ,turkey 7,london1 #ahfi74 ,see also ,,albania and the authorities there cited4 ,,iapetus1 in ,greek mythology1 son of ,uranus and ,gaea1 one of the ,titans1 father of ,atlas1 ,prometheus1 ,epimetheus and ,menoetius1 the personifications of certain human qualities 7,hesiod1 ,theog4 #ejg74 ,as a punishment for having revolted against ,zeus1 he was imprisoned in ,tartarus 7,homer1 ,iliad1 viii4 #dgi7 or underneath the island of ,inarime off the coast of ,campania 7,silius ,italicus xii4 #adh74 ,hyginus makes him the son of ,tartarus and ,gaea1 and one of the giants4 ,iapetus was considered the original ancestor of the human race1 as the father of ,prometheus and grandfather of ,deucalion4 ,the name is probably identical with ,japhet 7,japheth71 and the son of ,noah in the ,greek legend of the flood becomes the ancestor of 7,noah7 ,deucalion4 ,iapetus as the representative of an obsolete order of things is described as warring against the new order under ,zeus1 and is naturally relegated to ,tartarus4 ,see ,f4 ,g4 ,welcker1 ,griechische ,gtterlehre1 i4 7#aheg72 ,c4 ,h4 ,vlcker1 ,die ,mythologie des ,iapetischen ,geschlechtes 7#ahbd72 ,m4 ,mayer1 ,giganten und ,titanen 7#ahhg74 ,,iapydes1 or ,,iapodes1 one of the three chief peoples of ,roman ,illyria4 ,they occupied the interior of the country on the north between the ,arsia 7,arsa7 and ,tedanius 7perhaps the ,zermanja71 which separated them from the ,liburnians4 ,their territory formed part of the modern ,croatia4 ,they are described by ,strabo as a mixed race of ,celts and ,illyrians1 who used ,celtic weapons1 tattooed themselves1 and lived chiefly on spelt and millet4 ,they were a warlike race1 addicted to plundering expeditions4 ,in #abi ,b4,c4 ,c4 ,sempronius ,tuditanus celebrated a triumph over them1 and in #cd ,b4,c4 they were finally crushed by ,augustus4 ,they appear to have had a foedus with ,rome1 but subsequently rebelled4 ,see ,strabo iv4 #bjg1 vii4 #cac-cae2 ,dio ,cassius xlix4 #ce2 ,appian1 ,illyrica1 #aj1 #ad1 #af2 ,livy1 ,epit4 lix4 #aca2 ,tibullus iv4 #a4 #ajh2 ,cicero1 ,pro ,balbo1 #ad4 ,,iatrochemistry 7coined from ,gr4 ,greek3 iatros1 a physician1 and chemistry71 a stage in the history of chemistry1 during which the object of this science was held to be not to make gold but to prepare medicines4 ,this doctrine dominated chemical thought during the #afth century1 its foremost supporters being ,paracelsus1 van ,helmont and de la ,bo ,sylvius4 ,but it gave way to the new definition formulated by ,boyle1 viz4 that the proper domain of chemistry was to determine the composition of substances4 7,see ,,chemistry3 ,i4 ,history2 ,,medicine47 ,,iazyges1 a tribe of ,sarmatians first heard of on the ,maeotis1 where they were among the allies of ,mithradates the ,great4 ,moving westward across ,scythia1 and hence called ,metanastae1 they were on the lower ,danube by the time of ,ovid1 and about ,a4,d4 #ej occupied the plains east of the ,theiss4 ,here1 under the general name of ,sarmatae1 they were a perpetual trouble to the ,roman province of ,dacia4 ,they were divided into freemen and serfs 7,sarmatae ,limigantes71 the latter of whom had a different manner of life and were probably an older settled population enslaved by nomad masters4 ,they rose against them in ,a4,d4 #ccd1 but were repressed by foreign aid4 ,nothing is heard of ,iazyges or ,sarmatae after the ,hunnish invasions4 ,graves at ,keszthely and elsewhere in the ,theiss valley1 shown by their contents to belong to nomads of the first centuries ,a4,d41 are referred to the ,iazyges4 7,e4 ,h4 ,m47 ,,ibadan1 a town of ,british ,west ,africa1 in ,yorubaland1 ,southern ,nigeria1 #abc m4 by rail ,n4,e4 of ,lagos1 and about #ej m4 ,n4,e4 of ,abeokuta4 ,pop4 #aiaj estimated at #aej1jjj4 ,the town occupies the slope of a hill1 and stretches into the valley through which the river ,ona flows4 ,it is enclosed by mud walls1 which have a circuit of #ah m41 and is encompassed by cultivated land #e or #f m4 in breadth4 ,the native houses are all low1 thatched structures1 enclosing a square court1 and the only break in the mud wall is the door4 ,there are numerous mosques1 orishas 7idol-houses7 and open spaces shaded with trees4 ,there are a few buildings in the ,european style4 ,most of the inhabitants are engaged in agriculture2 but a great variety of handicrafts is also carried on4 ,ibadan is the capital of one of the ,yoruba states and enjoys a large measure of autonomy4 ,nominally the state is subject to the alafin 7ruler7 of ,oyo2 but it is virtually independent4 ,the administration is in the hands of two chiefs1 a civil and a military1 the bale and the balogun2 these together form the highest court of appeal4 ,there is also an iyaloda or mother of the town1 to whom are submitted all the disputes of the women4 ,ibadan long had a feud with ,abeokuta1 but on the establishment of the ,british protectorate the intertribal wars were stopped4 ,in #ahfb the people of ,ibadan destroyed ,ijaya1 a neighbouring town of #fj1jjj inhabitants4 ,a ,british resident and a detachment of ,hausa troops are stationed at ,ibadan4 ,see also ,,yorubas1 ,,abeokuta and ,,lagos4 ,,ibagu1 or ,,san ,,bonifacio ,,de ,,ibagu1 a city of ,colombia1 and capital of the department of ,tolima1 about #fj m4 ,w4 of ,bogot and #ah m4 ,n4,w4 of the ,nevado de ,tolima4 ,pop4 7#aijj1 estimate7 #ac1jjj4 ,ibagu is built on a beautiful plain between the ,chipalo and ,combeima1 small affluents of the ,cuello1 a western tributary of the ,magdalena4 ,its elevation1 #dcjj ft4 above the sea1 gives it a mild1 subtropical climate4 ,the plain and the neighbouring valleys produce cacao1 tobacco1 rice and sugar-cane4 ,there are two thermal springs in the vicinity1 and undeveloped mines of sulphur and silver4 ,the city has an endowed college4 ,it is an important commercial centre1 being on the road which crosses the ,quindio pass1 or paramo1 into the ,cauca valley4 ,ibagu was founded in #aeej and was the capital of the republic for a short time in #ahed4 ,,ibarra1 a city of ,ecuador and capital of the province of ,imbabura1 about #ej m4 ,n4,n4,e4 of ,quito1 on a small fertile plain at the northern foot of ,imbabura volcano1 #gcjj ft4 above sea-level4 ,pop4 7#aijj1 estimate7 #ejjj4 ,it stands on the left bank of the ,tahuando1 a small stream whose waters flow north and west to the ,pacific through the ,mira1 and is separated from the higher plateau of ,quito by an elevated transverse ridge of which the ,imbabura and ,mojanda volcanoes form a part4 ,the surrounding country is mountainous1 the valleys being very fertile4 ,ibarra itself has a mild1 humid climate1 and is set in the midst of orchards and gardens4 ,it is the see of a bishop and has a large number of churches and convents1 and many substantial residences4 ,ibarra has manufactures of cotton and woollen fabrics1 hats1 sandals 7alpargates71 sacks and rope from cabulla fibre1 laces1 sugar and various kinds of distilled spirits and cordials made from the sugar-cane grown in the vicinity4 ,mules are bred for the ,colombian markets of ,pasto and ,popayan4 ,ibarra was founded in #aeig by ,alvaro de ,ibarra1 the president of ,quito4 ,it has suffered from the eruptions of ,imbabura1 and more severely from earthquakes1 that of #ahei causing great damage to its public buildings1 and the greater one of the #afth of ,august #ahfh almost completely destroyed the town and killed a large number of its inhabitants4 ,the village of ,carranqui1 #a m4 from ,ibarra1 is the birthplace of ,atahualpa1 the ,inca sovereign executed by ,pizarro1 and close by is the small lake called ,yaguarcocha where the army of ,huaynacapac1 the father of ,atahualpa1 inflicted a bloody defeat on the ,carranquis4 ,another aboriginal battle-field is that of ,hatuntaqui1 near ,ibarra1 where ,huaynacapac won a decisive victory and added the greater part of ,ecuador to his realm4 ,the whole region is full of tolas1 or ,indian burial mounds4 ,,iberians 7,iberi1 ,greek3 ,ibres71 an ancient people inhabiting parts of the ,spanish peninsula4 ,their ethnic affinities are not known1 and our knowledge of their history is comparatively slight4 ,it is almost impossible to make any statement in regard to them which will meet with general agreement4 ,at the same time1 the general lines of ,iberian controversy are clear enough ,the principal sources of information about the ,iberians are 7#a7 historical1 7#b7 numismatic1 7#c7 linguistic1 7#d7 anthropological4 #a4 ,historical4--,the name seems to have been applied by the earlier ,greek navigators to the peoples who inhabited the eastern coast of ,spain2 probably it originally meant those who dwelt by the river ,iberus 7mod4 ,ebro74 ,it is possible 7,boudard1 tudes sur l'alphabet ibrien 7,paris1 #aheb7 that the river-name itself represents the ,basque phrase ibay-erri the country of the river4 ,on the other hand1 even in older ,greek usage 7as in ,thuc4 vi4 #a7 the term ,iberia is said to have embraced the country as far east as the ,rhone 7see ,herodorus of ,heraclea1 ,fragm4 ,hist4 ,gr4 ii4 #cd71 and by the time of ,strabo it was the common ,greek name for the ,spanish peninsula4 ,iberians thus meant sometimes the population of the peninsula in general and sometimes1 it would appear1 the peoples of some definite race 7,greek3 genos7 which formed one element in that population4 ,of the tribal distribution of this race1 of its linguistic1 social and political characteristics1 and of the history of its relation to the other peoples of ,spain1 we have only the most general1 fragmentary and contradictory accounts4 ,on the whole1 the historical evidence indicates that in ,spain1 when it first became known to the ,greeks and ,romans there existed many separate and variously civilized tribes connected by at least apparent identity of race1 and by similarity 7but not identity7 of language1 and sufficiently distinguished by their general characteristics from ,phoenicians1 ,romans and ,celts4 ,the statement of ,diodorus ,siculus that the mingling of these ,iberians with the immigrant ,celts gave rise to the ,celtiberians is in itself probable4 ,varro and ,dionysius ,afer proposed to identify the ,iberians of ,spain with the ,iberians of the ,caucasus1 the one regarding the eastern1 and other the western1 settlements as the earlier4 #b4 ,numismatic4--,knowledge of ancient ,iberian language and history is mainly derived from a variety of coins1 found widely distributed in the peninsula1#a and also in the neighbourhood of ,narbonne4 ,they are inscribed in an alphabet which has many points of similarity with the western ,greek alphabets1 and some with the ,punic alphabet2 but which seems to retain a few characters from an older script akin to those of ,minoan ,crete and ,roman ,libya4#b ,the same ,iberian alphabet is found also rarely in inscriptions4 ,the coinage began before the ,roman conquest was completed2 the monetary system resembles that of the ,roman republic1 with values analogous to denarii and quinarii4 ,the coin inscriptions usually give only the name of the town1 e4g4 ,,plplis 7,bilbilis71 ,,klaqriqs 7,calagurris71 ,,seqbrics 7,segobriga71 ,,tmaniav 7,dumania74 ,the types show late ,greek and perhaps also late ,punic influence1 but approximate later to ,roman models4 ,the commonest reverse type1 a charging horseman1 reappears on the ,roman coins of ,bilbilis1 ,osca1 ,segobriga and other places4 ,another common type is one man leading two horses or brandishing a sword or a bow4 ,the obverse has usually a male head1 sometimes inscribed with what appears to be a native name4 #c4 ,linguistic4--,the survival of the non-,aryan language among the ,basques around the west ,pyrenees has suggested the attempt to interpret by its means a large class of similar-sounding place-names of ancient ,spain1 some of which are authenticated by their occurrence on the inscribed coins1 and to link it with other traces of non-,aryan speech round the shores of the ,western ,mediterranean and on the ,atlantic seaboard of ,europe4 ,this phase of ,iberian theory opens with ,k4 ,w4 ,humboldt 7,prfung der ,untersuchungen ber die ,urbewohner ,hispaniens vermittelst der waskischen ,sprache1 ,berlin1 #ahba71 who contended that there existed once a single great ,iberian people1 speaking a distinct language of their own2 that an essentially ,iberian population was to be found in ,sicily1 ,sardinia and ,corsica1 in southern ,france1 and even in the ,british ,isles2 and that the ,basques of the present day were remnants of this race1 which had elsewhere been expelled or absorbed4 ,this last was the central and the seminal idea of the work1 and it has been the point round which the battle of scholarship has mainly raged4 ,the principal evidence which ,humboldt adduced in its support was the possibility of explaining a vast number of the ancient topographical names of ,spain1 and of other asserted ,iberian districts1 by the forms and significations of ,basque4 ,in reply1 ,graslin 7,de l',ibrie1 ,paris1 #ahci71 maintained that the name ,iberia was nothing but a ,greek misnomer of ,spain1 and that there was no proof that the ,basque people had ever occupied a wider area than at present2 and ,blad 7,origine des ,basques1 ,paris1 #ahfi7 took the same line of argument1 holding that ,iberia is a purely geographical term1 that there was no proper ,iberian race1 that the ,basques were always shut in by alien races1 that their affinity is still to seek1 and that the whole ,basque-,iberian theory is a figment4 ,his main contention has met with some acceptance1#c but the great current of ethnographical speculation still flows in the direction indicated by ,humboldt4 #d4 ,anthropological4--,humboldt's ,iberian theory depended partly on linguistic comparisons1 but partly on his observation of widespread similarity of physical type among the population of south-western ,europe4 ,since his time the anthropological researches of ,broca1 ,thurnam and ,davis1 ,huxley1 ,busk1 ,beddoe1 ,virchow1 ,tubino and others have proved the existence in ,europe1 from ,neolithic times1 of a race1 small of stature1 with long or oval skulls1 and accustomed to bury their dead in tombs4 ,their remains have been found in ,belgium and ,france1 in ,britain1 ,germany and ,denmark1 as well as in ,spain2 and they bear a close resemblance to a type which is common among the ,basques as well as all over the ,iberian peninsula4 ,this ,neolithic race has consequently been nicknamed ,iberians1 and it is now common to speak of the ,iberian ancestry of the people of ,britain1 recognizing the racial characteristics of ,iberians in the small swarthy ,welshman1 the small dark ,highlander1 and the ,black ,celts to the west of the ,shannon1 as well as in the typical inhabitants of ,aquitania and ,brittany4#d ,later investigators went further4 ,m4 d',arbois de ,jubainville1 for example 7,les ,premiers habitants de l',europe1 ,paris1 #ahgg71 maintained that besides possessing ,spain1 ,gaul1 ,italy and the ,british ,isles1 ,iberian peoples penetrated into the ,balkan peninsula1 and occupied a part of northern ,africa1 ,corsica and ,sardinia2 and it is now generally accepted that a race with fairly uniform characteristics was at one time in possession of the south of ,france 7or at least of ,aquitania71 the whole of ,spain from the ,pyrenees to the straits1 the ,canary ,islands 7the ,guanches7 a part of northern ,africa and ,corsica4 ,whether this type is more conveniently designated by the word ,iberian1 or by some other name 7,eur-african1 ,mediterranean1 c47 is a matter of comparative indifference1 provided that there is no misunderstanding as to the steps by which the term ,iberian attained its meaning in modern anthropology4 ,,authorities4--,k4 ,w4 von ,humboldt1 ber die cantabrische oder baskische ,sprache in ,adelung1 ,mithridates iv4 7#ahag71 and ,prfung d4 ,untersuchungen 4 die ,urbewohner ,hispaniens vermittelst der waskischen ,sprache 7,berlin1 #ahba72 ,l4 ,f4 ,graslin1 ,de l',ibrie 7,paris1 #ahch72 ,t4 ,b4 ,g4 ,m4 ,bory de ,st ,vincent1 ,essai gologique sur le genre humain 7#ahch72 ,g4 ,lagneau1 ,sur l'ethnologie des peuples ibriens1 in ,bull4 soc4 anthrop4 7#ahfg71 pp4 #adf-afa2 ,j4 ,f4 ,blad1 tudes sur l'origine des ,basques 7,paris1 #ahfi71 ,dfense des tudes1 c4 7,paris1 #ahgj72 ,phillips1 ,die ,einwanderung der ,iberer in die pyren4 ,halbinsel 7,vienna1 #ahgj71 ber das iberische ,alphabet 7,vienna1 #ahgj72 ,w4 ,boyd ,dawkins1 ,the ,northern ,range of the ,basques1 in ,fortnightly ,rev4 ,n4,s4 xvi4 #cbc-ccg 7#ahgd72 ,w4 ,t4 van ,eys1 ,la ,langue ibrienne et la langue basque1 in ,revue de linguistique1 pp4 #c-ae 7#ahgd72 ,w4 ,webster1 ,the ,basque and the ,kelt1 in ,journ4 ,anthrop4 ,inst4 v4 #e-bi 7#ahge72 ,f4 ,m4 ,tubino1 ,los ,aborigines ibericos o los ,berberos en la peninsula 7,madrid1 #ahgf72 ,a4 ,luchaire1 ,les ,origines linguistiques de l',aquitaine 7,paris1 #ahgg72 ,w4 ,boyd ,dawkins1 ,early ,man in ,britain 7,london1 #ahhj72 ,a4 ,castaing1 ,les ,origines des ,aquitains1 ,mm4 ,soc4 ,eth4 ,n4,s4 #a1 pp4 #ahc-cbh 7#ahhd72 ,g4 ,c4 ,c4 ,gerland1 ,die ,basken und die ,iberer in ,grber1 ,grundriss d4 roman4 ,philologie1 #a1 pp4 #cac-ccd 7#ahhh72 ,m4 ,h4 d',arbois de ,jubainville1 ,les ,premiers habitants de l',europe 7#ahhi-ahid72 ,j4 ,f4 ,blad1 ,les ,vascons avant leur tablissement en ,novempopulanie1 ,agen4 7#ahia72 ,w4 ,webster1 ,the ,celt-iberians1 ,academy xl4 #bfh-bfi 7and consequent correspondence7 7#ahia72 ,j4 ,rhys1 ,the ,inscriptions and ,language of the ,northern ,picts1 ,proc4 ,soc4 ,ant4 ,scot4 xxvi4 #bfc-cea 7#ahib72 ,f4 ,fita1 ,el ,vascuence en las inscripciones gmicas1 ,bol4 ,real4 ,acad4 ,hist4 ,madrid 7,june #ahic71 xxii4 #egi-ehg2 ,g4 v4 d4 ,gabelentz1 ,baskisch u4 ,berberisch1 ,sitz4 k4 preuss4 ,akad4 ,wiss4 #eic-fac 7,berlin1 #ahic71 ,die ,verwandtschaft der ,baskischen mit der ,berber-,sprache ,nordafrikas nachgewiesen 7,braunschweig1 #ahid72 ,m4 ,h4 d',arbois de ,jubainville1 ,les ,celtes en ,espagne1 ,rev4 celtique1 xiv4 #ceg-cie 7#ahid72 ,g4 ,buschan1 ber die iberische ,rasse1 ,ausland1 lxvi4 #cdb-cdd 7#ahid72 ,f4 ,olriz y ,aguilera1 ,distribucion geografica del indice cefalico en ,espaa 7,madrid1 #ahid71 ,la ,talla humana en ,espaa in ,discursos ,r4 ,acad4 ,medicina xxxvi4 #chi 7,madrid1 #ahif72 ,r4 ,collignon1 ,la ,race basque1 ,l',anthropologie1 v4 #bgf-bhg 7#ahid72 ,t4 de ,aranzadi1 ,le ,peuple basque1 rsum ,bull4 soc4 d'anth4 #eaj-ebj 7#ahid71 ,consideraciones acerca de la raza basca ,euskel-,erria xxxv4 #cc1 #fe1 #ig1 #abi 7#ahif72 ,h4 ,schuchhardt1 ,baskische ,studien1 i4 ber die ,entstehung der ,bezugsformen des baskischen ,zeitworts2 ,denkschriften der ,k4 ,akad4 der ,wiss41 ,phil4-,hist41 ,classe1 ,bd4 #db1 ,abh4 #c4 7,wien1 #ahic72 ,ph4 ,salmon1 ,rev4 mens4 c4 d'anthr4 v4 #aee-aha1 #bad-bbj 7#ahie72 ,r4 ,collignon1 ,anthr4 du ,s4-,o4 de la ,france1 ,mm4 ,soc4 ,anthr4 #c4 #a4 #d4 p4 #a-abi 7#ahie71 ,ann4 de gogr4 v4 #aef-aff 7#ahif71 and with ,j4 ,deniker1 ,les ,maures de ,sngal1 ,l',anthr4 vii4 #eg-fi 7#ahig72 ,g4 ,herv1 ,rev4 mens4 c4 d'anthr4 vi4 #ig-aji 7#ahif72 ,g4 ,sergi1 ,africa3 ,anthropologia della stirpe ,camitica 7,turin1 #ahig71 ,arii ed ,italici 7#ahih72 ,l4 de ,hoyos ,sainz1 ,l',anthropologie et la prhistorique en ,espagne et en ,portugal en #ahig1 ,l',anthropologie1 ix4 #cg-ea 7#ahih72 ,j4 ,deniker 7see ,collignon7 ,les ,races de l',europe1 ,l',anthropologie1 ix4 #aac-acc 7#ahih72 ,m4 ,gze1 ,de quelques rapports entre les langues berbre et basque1 ,mm4 soc4 arch4 du ,midi de la ,france1 xiii4 ,see also the works quoted in the footnotes2 and the bibliography under ,,basques4 7,j4 ,l4 ,m47 ,,footnotes3 #a ,for the prehistoric civilization of the peninsula as a whole see ,,spain4 #b ,p4 ,a4 ,boudard's tudes sur l'alphabet ibrien 7,paris1 #aheb74 and ,numismatique ibrienne 7,bziers1 #ahei72 ,aloiss ,heiss1 ,notes sur les monnaies celtibriennes 7,paris1 #ahfe71 and ,description gnrale des monnaies antiques de l',espagne 7,paris1 #ahgj72 ,phillips1 ber das iberische ,alphabet 7,vienna1 #ahgj71 ,die ,einwanderung der ,iberer in die pyren4 ,halbinsel 7,vienna1 #ahgj72 ,w4 ,m4 ,flinders ,petrie1 ,journ4 ,anthr4 ,inst4 xxix4 7#ahii7 #bjd1 and above all ,e4 ,hbner1 ,monumenta linguae ,ibericae4 #c ,w4 van ,eys1 for example1 ,la ,langue ibrienne et la langue basque1 in ,revue de linguistique1 goes against ,humboldt2 but ,prince ,napoleon and to a considerable extent ,a4 ,luchaire maintain the justice of his method and the value of many of his results4 ,see ,luchaire1 ,les ,origines linguistiques de l',aquitaine 7,paris1 #ahgg74 #d ,compare the interesting rsum of the whole question in ,boyd ,dawkins's ,early ,man in ,britain 7,london1 #ahhj74 ,,ibex1 one of the names of the ,alpine wild goat1 otherwise known as the steinbok and bouquetin1 and scientifically as ,capra ibex4 ,formerly the ibex was common on the mountain-ranges of ,germany1 ,switzerland and ,tirol1 but is now confined to the ,alps which separate ,valais from ,piedmont1 and to the lofty peaks of ,savoy1 where its existence is mainly due to game-laws4 ,the ibex is a handsome animal1 measuring about #d ft4 in length and standing about #dj in4 at the shoulder4 ,the skin is covered in summer with a short fur of an ashy-grey colour1 and in winter with much longer yellowish-brown hair concealing a dense fur beneath4 ,the horns of the male rise from the crest of the skull1 and after bending gradually backwards terminate in smooth tips2 the front surface of the remainder carrying bold transverse ridges or knots4 ,about #a yd4 is the maximum recorded length of ibex-horns4 ,the fact that the fore-legs are somewhat shorter than those behind enables the ibex to ascend mountain slopes with more facility than it can descend1 while its hoofs are as hard as steel1 rough underneath and when walking over a flat surface capable of being spread out4 ,these1 together with its powerful sinews1 enable it to take prodigious leaps1 to balance itself on the smallest foothold and to scale almost perpendicular rocks4 ,ibex live habitually at a greater height than chamois or any other ,alpine mammals1 their vertical limit being the line of perpetual snow4 ,there they rest in sunny nooks during the day1 descending at night to the highest woods to graze4 ,ibex are gregarious1 feeding in herds of ten to fifteen individuals2 but the old males generally live apart from1 and usually at greater elevations than1 the females and young4 ,they utter a sharp whistling sound not unlike that of the chamois1 but when greatly irritated or frightened make a peculiar snorting noise4 ,the period of gestation in the female is ninety days1 after which she produces--usually at the end of ,june--a single young one which is able at once to follow its mother4 ,kids when caught young and fed on goat's milk can be readily tamed2 and in the #afth century young tamed ibex were frequently driven to the mountains along with the goats1 in whose company they would afterwards return4 ,even wild ibex have been known to stray among the herds of goats1 although they shun the society of chamois4 ,its flesh is said to resemble mutton1 but has a flavour of game4 ,illustration3 ,the ,ibex 7,capra ibex74 ,by naturalists the name ibex has been extended to embrace all the kindred species of wild goats1 while by sportsmen it is used in a still more elastic sense1 to include not only the true wild goat 7known in ,india as the ,sind ibex7 but even the short-horned ,hemitragus hylocrius of the ,nilgiris4 ,dealing only with species zoologically known as ibex1 the one nearest akin to the ,european kind is the ,asiatic or ,siberian ibex 7,capra sibirica71 which1 with several local phases1 extends from the northern side of ,kashmir over an enormous area in ,central ,asia4 ,these ibex1 especially the race from the ,thian ,shan1 are incomparably finer than the ,european species1 their bold knotted horns sometimes attaining a length of close on #fj in4 ,the ,arabian1 or ,nubian1 ibex 7,c4 nubiana7 is characterized by the more slender type of horn1 in which the front edge is much narrower2 while the ,simien ibex 7,c4 vali7 of ,central ,abyssinia is a very large and dark-coloured animal1 with the horns black instead of brownish1 and bearing only slightly marked front ridges4 ,the ,caucasian ibex 7,c4 caucasica71 or tur1 is a wholly fox-coloured animal1 in which the horns are still flatter in front1 and thus depart yet further from the ibex type4 ,in the ,spanish ibex 7,c4 pyrenaica7 the horns are flattened1 with ill-defined knobs1 and a spiral twist4 7,see ,,goat47 7,w4 ,h4 ,f42 ,r4 ,l4997 ,,ibis1 one of the sacred birds of the ancient ,egyptians4 ,james ,bruce identified this bird with the ,abu-,hannes or ,father ,john of the ,abyssinians1 and in #agij it received from ,latham 7,index ornithologicus1 p4 #gjf7 the name of ,tantalus aethiopicus4 ,this determination was placed beyond question by ,cuvier 7,ann4 du ,musum1 iv4 #aaf-ace7 and ,savigny 7,hist4 nat4 et mythol4 de l'ibis7 in #ahje4 ,they1 however1 removed it from the ,linnaean genus ,tantalus and1 ,lacpde having some years before founded a genus ,ibis1 it was transferred thither1 and is now generally known as ,i4 aethiopica1 though some speak of it as ,i4 religiosa4 ,no attempt can here be made to treat the ibis from a mythological or antiquarian point of view4 ,savigny's memoir contains a great deal of matter on the subject4 ,wilkinson 7,ancient ,egyptians1 ser4 #b1 vol4 ii4 pp4 #bag-bbd7 added some of the results of later research1 and ,renouf in his ,hibbert ,lectures explains the origin of the myth4 ,the ibis is chiefly an inhabitant of the ,nile basin from ,dongola southward1 as well as of ,kordofan and ,sennar2 whence about midsummer it moves northwards to ,egypt4#a ,in ,lower ,egypt it bears the name of ,abu-mengel1 or father of the sickle1 from the form of its bill1 but it does not stay long in that country1 disappearing when the ,nile has subsided4 ,hence most travellers have failed to meet with it there#b 7since their acquaintance with the birds of ,egypt is limited to those which frequent the country in winter71 and writers have denied generally to this species a place in its modern fauna 7cf4 ,shelley1 ,birds of ,egypt1 p4 #bfa74 ,however1 in #ahfd1 von ,heuglin 7,journ4 fr ,ornithologie1 #ahfe1 p4 #ajj7 saw a young bird which had been shot in the ,delta1 and ,e4 ,c4 ,taylor 7,ibis1 #ahgh1 p4 #cgb7 saw an adult which had been killed near ,lake ,menzal in #ahgg4 ,the story told to ,herodotus of its destroying snakes is1 according to ,savigny1 devoid of truth1 but ,cuvier states that he discovered partly digested remains of a snake in the stomach of a mummied ibis4 ,the ibis is somewhat larger than a curlew1 ,numenius arquata1 which bird it resembles1 with a much stouter bill and stouter legs4 ,the head and greater part of the neck are bare and black4 ,the plumage is white1 except the primaries1 which are black1 and a black plume1 formed by the secondaries1 tertials and lower scapulars1 and richly glossed with bronze1 blue and green1 which curves gracefully over the hind-quarters4 ,the bill and feet are also black4 ,the young lack the ornamental plume1 and in them the head and neck are clothed with short black feathers1 while the bill is yellow4 ,the nest is placed in bushes or high trees1 the bird generally building in companies1 and in the middle of ,august von ,heuglin 7,orn4 ,nord-,ost-,afrikas1 p4 #aach7 found that it had from two to four young or much incubated eggs4#c ,these are of a dingy white1 splashed1 spotted and speckled with reddish-brown4 ,congeneric with the typical ibis are two or three other species1 the ,i4 melanocephala of ,india1 the ,i4 molucca or ,i4 strictipennis1 of ,australia1 and the ,i4 bernieri of ,madagascar1 all of which closely resemble ,i4 aethiopica2 while many other forms not very far removed from it1 though placed by authors in distinct genera1#d are known4 ,among these are several beautiful species such as the ,japanese ,geronticus nippon1 the ,lophotibis cristata of ,madagascar1 and the scarlet ibis1#e ,eudocimus ruber1 of ,america4 ,the glossy ibis1 ,plegadis falcinellus1 found throughout the ,west ,indies1 ,central and the south-eastern part of ,north ,america1 as well as in many parts of ,europe 7whence it not unfrequently strays to the ,british ,islands71 ,africa1 ,asia and ,australia4 ,this bird1 believed to be the second kind of ibis spoken of by ,herodotus1 is rather smaller than the sacred ibis1 and mostly of a dark chestnut colour with brilliant green and purple reflections on the upper parts1 exhibiting1 however1 when young none of the rufous hue4 ,this species lays eggs of a deep sea-green colour1 having wholly the character of heron's eggs1 and it often breeds in company with herons1 while the eggs of all other ibises whose eggs are known resemble those of the sacred ibis4 ,though ibises resemble the curlews externally1 there is no affinity between them4 ,the ,ibididae are more nearly related to the storks1 ,ciconiidae1 and still more to the spoonbills1 ,plataleidae1 with which latter many systematists consider them to form one group1 the ,hemiglottides of ,nitzsch4 ,together these groups form the sub-order ,ciconiae of the order ,ciconiiformes4 ,the true ibises are also to be clearly separated from the wood-ibises1 ,tantalidae1 of which there are four or five species1 by several not unimportant structural characters4 ,fossil remains of a true ibis1 ,i4 pagana1 have been found in considerable numbers in the middle ,tertiary beds of ,france4#f 7,a4 ,n47 ,,footnotes3 #a ,it has been said to occur occasionally in ,europe 7,greece and southern ,russia74 #b ,e4 ,c4 ,taylor remarked 7,ibis1 #ahei1 p4 #ea71 that the buff-backed heron1 ,ardea bubulcus1 was made by the tourists' dragomans to do duty for the sacred ibis1 and this seems to be no novel practice1 since by it1 or something like it1 ,hasselqvist was misled1 and through him ,linnaeus4 #c ,the ibis has more than once nested in the gardens of the ,zoological ,society in ,london1 and even reared its young there4 #d ,for some account of these may be consulted ,dr ,reichenow's paper in ,journ4 fr ,ornithologie 7#ahgg71 pp4 #adc-aef2 ,elliot's in ,proc4 ,zool4 ,society 7#ahgg71 pp4 #dgg-eaj2 and that of ,oustalet in ,nouv4 ,arch4 du ,musum1 ser4 #b1 vols4 i4 pp4 #afg-ahd4 #e ,it is a popular error--especially among painters--that this bird was the sacred ibis of the ,egyptians4 #f ,the name ,ibis was selected as the title of an ornithological magazine1 frequently referred to in this and other articles1 which made its first appearance in #ahei4 ,,iblis1 or ,,eblis1 in ,moslem mythology the counterpart of the ,christian and ,jewish devil4 ,he figures oftener in the ,koran under the name ,shaitan1 ,iblis being mentioned #aa times1 whereas ,shaitan appears in #hg passages4 ,he is chief of the spirits of evil1 and his personality is adapted to that of his ,jewish prototype4 ,iblis rebelled against ,allah and was expelled from ,paradise4 ,the ,koranic legend is that his fall was a punishment for his refusal to worship ,adam4 ,condemned to death he was afterwards respited till the judgment day 7,koran vii4 #ac74 ,see ,gustav ,weil1 ,the ,bible1 the ,koran and the ,talmud 7,london1 #ahdf74 ,,ibn ',,abd ,,rabbihi ,abu ',umar ,ahmad ibn ,mahommed ibn ',abd ,rabbihi 7#hfj-idj71 ,arabian poet1 was born in ,cordova and descended from a freed slave of ,hisham1 the second ,spanish ,omayyad caliph4 ,he enjoyed a great reputation for learning and eloquence4 ,no diwan of his is extant1 but many selections from his poems are given in the ,yatimat ud-,dahr1 i4 #dab-dcf 7,damascus1 #ahhg74 ,more widely known than his poetry is his great anthology1 the ',iqd ul-,farid 7,the ,precious ,necklace71 a work divided into twenty-five sections1 the thirteenth being named the middle jewel of the necklace1 the chapters on either side of this being named after other jewels4 ,it is an adab book 7see ,,arabia3 ,literature1 section ,belles ,lettres7 resembling ,ibn ,qutaiba's ',uyun ul-,akhbar1 from which it borrows largely4 ,it has been printed1 several times in ,cairo 7#ahgf1 #ahhf1 c474 7,g4 ,w4 ,t47 ,,ibn ',,arabi ,muhyiuddin ,abu ',abdallah ibn ul-',arabi 7#aafe-abdj71 ,moslem theologian and mystic1 was born in ,murcia and educated in ,seville4 ,when thirty-eight he travelled in ,egypt1 ,arabia1 ,bagdad1 ,mosul and ,asia ,minor1 after which he lived in ,damascus for the rest of his life4 ,in law he was a ,zahirite1 in theology a mystic of the extreme order1 though professing orthodox ,ash'arite theology and combating in many points the ,indo-,persian mysticism 7pantheism74 ,he claims to have had conversations with all the prophets past and future1 and reports conversations with ,god himself4 ,of his numerous works about #aej still exist4 ,the most extensive is the twelve-volume ,futuhat ul-,makkiyat 7,meccan ,revelations71 a general encyclopaedia of ,sufic beliefs and doctrines4 ,numerous extracts from this work are contained in ,sha'rani's 7d4 #aefe7 manual of ,sufic dogma 7,yawaqit7 published several times in ,cairo4 ,a short account of these works is given in ,a4 von ,kremer's ,geschichte der herrschenden ,ideen des ,islams1 pp4 #ajb-aji 7,leipzig1 #ahfh74 ,another characteristic and more accessible work of ,ibn ',arabi is the ,fusus ul-,hikam1 on the nature and importance of the twenty-seven chief prophets1 written in #abcj 7ed4 ,bulaq1 #ahcg7 and with the ,commentary 7,cairo1 #ahia7 of ,qashani 7d4 #acej72 cf4 analysis by ,m4 ,schreiner in ,journal of ,german ,oriental ,society1 lii4 #eaf-ebe4 ,of some #bhi works said to have been written by ,ibn ',arabi #aej are mentioned in ,c4 ,brockelmann's ,gesch4 der arabischen ,litteratur1 vol4 i4 7,weimar1 #ahih71 pp4 #dda-ddh4 ,see also ,r4 ,a4 ,nicholson1 ,a ,literary ,history of the ,arabs1 pp4 #cii-djd 7,london1 #aijg74 7,g4 ,w4 ,t47 ,,ibn ,,athir1 the family name of three brothers1 all famous in ,arabian literature1 born at ,jazirat ibn ',umar in ,kurdistan4 ,the eldest brother1 known as ,,majd ,,ud-,,din 7#aadi-abaj71 was long in the service of the amir of ,mosul1 and was an earnest student of tradition and language4 ,his dictionary of traditions 7,kitab un-,nihaya7 was published at ,cairo 7#ahic71 and his dictionary of family names 7,kitab ul-,murassa'7 has been edited by ,seybold 7,weimar1 #ahif74 ,the youngest brother1 known as ,,diya ,,ud-,,din 7#aafc-abci71 served ,saladin from #aaia on1 then his son1 al-,malik ul-,afdal1 and was afterwards in ,egypt1 ,samosata1 ,aleppo1 ,mosul and ,bagdad4 ,he was one of the most famous aesthetic and stylistic critics in ,arabian literature4 ,his ,kitab ul-,mathal1 published in ,bulaq in #ahfe 7cf4 ,journal of the ,german ,oriental ,society1 xxxv4 #adh1 and ,goldziher's ,abhandlungen1 i4 #afa sqq471 contains some very independent criticism of ancient and modern ,arabic verse4 ,some of his letters have been published by ,d4 ,s4 ,margoliouth ,on the ,royal ,correspondence of ,diya ed-,din el-,jazari in the ,actes du dixime congrs international des orientalistes1 sect4 #c1 pp4 #g-ba4 ,the brother best known by the simple name of ,ibn ,athir was ,,abu-,l-,,hasan ',,izzuddin ,,mahommed ,,ibn ,,ul-,,athir 7#aafj-abcd71 who devoted himself to the study of history and tradition4 ,at the age of twenty-one he settled with his father in ,mosul and continued his studies there4 ,in the service of the amir for many years1 he visited ,bagdad and ,jerusalem and later ,aleppo and ,damascus4 ,he died in ,mosul4 ,his great history1 the ,kamil1 extends to the year #abca2 it has been edited by ,c4 ,j4 ,tornberg1 ,ibn al-,athiri ,chronicon quod perfectissimum inscribitur 7#ad vols41 ,leiden1 #ahea-ahgf71 and has been published in #ab vols4 in ,cairo 7#ahgc and #ahhf74 ,the first part of this work up to ,a4,h4 #caj 7,a4,d4 #ibc7 is an abbreviation of the work of ,tabari 7q4v47 with additions4 ,ibn ,athir also wrote a history of the ,atabegs of ,mosul1 published in the ,recueil des historiens des croisades 7vol4 ii41 ,paris72 a work 7,usd ul-,ghaba71 giving an account of #gejj companions of ,mahomet 7#e vols41 ,cairo1 #ahfc71 and a compendium 7the ,lubab7 of ,sam'ani's ,kitab ul-,ansab 7cf4 ,f4 ,wstenfeld's ,specimen el-,lobabi1 ,gttingen1 #ahce74 7,g4 ,w4 ,t47 ,,ibn ,,batuta1 i4e4 ,,abu ,,abdullah ,,mahommed1 surnamed ,,ibn ,,batuta 7#acjd-acgh71 the greatest of ,moslem travellers1 was born at ,tangier in #acjd4 ,he entered on his travels at twenty-one 7#acbe7 and closed them in #acee4 ,he began by traversing the coast of the ,mediterranean from ,tangier to ,alexandria1 finding time to marry two wives on the road4 ,after some stay at ,cairo1 then probably the greatest city in the world 7excluding ,china71 and an unsuccessful attempt to reach ,mecca from ,aidhab on the west coast of the ,red ,sea1 he visited ,palestine1 ,aleppo and ,damascus4 ,he then made the pilgrimage to ,mecca and ,medina1 and visited the shrine of ,ali at ,mashhad-,ali1 travelling thence to ,basra1 and across the mountains of ,khuzistan to ,isfahan1 thence to ,shiraz and back to ,kufa and ,bagdad4 ,after an excursion to ,mosul and ,diarbekr1 he made the haj a second time1 staying at ,mecca three years4 ,he next sailed down the ,red ,sea to ,aden 7then a place of great trade71 the singular position of which he describes1 noticing its dependence for water-supply upon the great cisterns restored in modern times4 ,he continued his voyage down the ,african coast1 visiting1 among other places1 ,mombasa and ,quiloa 7,kilwa74 ,returning north he passed by the chief cities of ,oman to ,new ,ormuz 7,hurmuz71 which had about #ae years before1 c4 #acae1 been transferred to its famous island-site from the mainland 7,old ,ormuz74 ,after visiting other parts of the gulf he crossed the breadth of ,arabia to ,mecca1 making the haj for the third time4 ,crossing the ,red ,sea1 he made a journey of great hardship to ,syene1 and thence along the ,nile to ,cairo4 ,after this1 travelling through ,syria1 he made a circuit among the petty ,turkish states into which ,asia ,minor was divided after the fall of the kingdom of ,rum 7,iconium74 ,he now crossed the ,black ,sea to ,kaffa1 then mainly occupied by the ,genoese1 and apparently the first ,christian city he had seen1 for he was much perturbed by the bell-ringing4 ,he next travelled into ,kipchak 7the ,mongol khanate of ,russia71 and joined the camp of the reigning khan ,mahommed ,uzbeg1 from whom the great and heterogeneous ,uzbeg race is perhaps named4 ,among other places in this empire he travelled to ,bolghar 7#ed #ed ,n47 in order to witness the shortness of the summer night1 and desired to continue his travels north into the ,land of ,darkness 7in the extreme north of ,russia71 of which wonderful things were told1 but was obliged to forego this4 ,returning to the khan's camp he joined the cortge of one of the ,khatuns1 who was a ,greek princess by birth 7probably illegitimate7 and in her train travelled to ,constantinople1 where he had an interview with the emperor ,andronikos ,,iii4 the ,younger 7#acbh-acda74 ,he tells how1 as he passed the city gates1 he heard the guards muttering ,sarakinu4 ,returning to the court of ,uzbeg1 at ,sarai on the ,volga1 he crossed the steppes to ,khwarizm and ,bokhara2 thence through ,khorasan and ,kabul1 and over the ,hindu ,kush 7to which he gives that name1 its first occurrence74 ,he reached the ,indus1 on his own statement1 in ,september1 #accc4 ,this closes the first part of his narrative4 ,from ,sind1 which he traversed to the sea and back again1 he proceeded to ,multan1 and eventually1 on the invitation of ,mahommed ,tughlak1 the reigning sovereign1 to ,delhi4 ,mahommed was a singular character1 full of pretence at least to many accomplishments and virtues1 the founder of public charities1 and a profuse patron of scholars1 but a parricide1 a fratricide1 and as madly capricious1 bloodthirsty and unjust as ,caligula4 ,no day did his palace gate fail to witness the elevation of some abject to affluence and the torture and murder of some living soul4 ,he appointed the traveller to be kazi of ,delhi1 with a present of #ab1jjj silver dinars 7rupees71 and an annual salary of the same amount1 besides an assignment of village lands4 ,in the sultan's service ,ibn ,batuta remained eight years2 but his good fortune stimulated his natural extravagance1 and his debts soon amounted to four or five times his salary4 ,at last he fell into disfavour and retired from court1 only to be summoned again on a congenial duty4 ,the emperor of ,china1 last of the ,mongol dynasty1 had sent a mission to ,delhi1 and the ,moor was to accompany the return embassy 7#acdb74 ,the party travelled through central ,india to ,cambay and thence sailed to ,calicut1 classed by the traveller with the neighbouring ,kaulam 7,quilon71 ,alexandria1 ,sudak in the ,crimea1 and ,zayton 7,amoy harbour7 in ,china1 as one of the greatest trading havens in the world--an interesting enumeration from one who had seen them all4 ,the mission party was to embark in ,chinese junks 7the word used7 and smaller vessels1 but that carrying the other envoys and the presents1 which started before ,ibn ,batuta was ready1 was wrecked totally2 the vessel that he had engaged went off with his property1 and he was left on the beach of ,calicut4 ,not daring to return to ,delhi1 he remained about ,honore and other cities of the western coast1 taking part in various adventures1 among others the capture of ,sindabur 7,goa71 and visiting the ,maldive ,islands1 where he became kazi1 and married four wives1 and of which he has left the best medieval account1 hardly surpassed by any modern4 ,in ,august #acdd he left the ,maldives for ,ceylon2 here he made the pilgrimage to the ,footmark of our ,father ,adam4 ,thence he betook himself to ,maabar 7the ,coromandel coast71 where he joined a ,mussulman adventurer1 residing at ,madura1 who had made himself master of much of that region4 ,after once more visiting ,malabar1 ,canara and the ,maldives1 he departed for ,bengal1 a voyage of forty-three days1 landing at ,sadkawan 7,chittagong74 ,in ,bengal he visited the famous ,moslem saint ,shaykh ,jalaluddin1 whose shrine 7,shah ,jalal at ,silhet7 is still maintained4 ,returning to the delta1 he took ship at ,sunarganw 7near ,dacca7 on a junk bound for ,java 7i4e4 ,java ,minor of ,marco ,polo1 or ,sumatra74 ,touching the coast of ,arakan or ,burma1 he reached ,sumatra in forty days1 and was provided with a junk for ,china by ,malik al ,dhahir1 a zealous disciple of ,islam1 which had recently spread among the states on the northern coast of that island4 ,calling 7apparently7 at ,cambodia on his way1 ,ibn ,batuta reached ,china at ,zayton 7,amoy harbour71 famous from ,marco ,polo2 he also visited ,sin ,kalan or ,canton1 and professes to have been in ,khansa 7,kinsay of ,marco ,polo1 i4e4 ,hangchau71 and ,khanbalik 7,cambaluc or ,peking74 ,the truth of his visit to these two cities1 and especially to the last1 has been questioned4 ,the traveller's history1 not least in ,china1 singularly illustrates the free masonry of ,islam1 and its power of carrying a ,moslem doctor over the known world of ,asia and ,africa4 ,on his way home he saw the great bird ,rukh 7evidently1 from his description1 an island lifted by refraction72 revisited ,sumatra1 ,malabar1 ,oman1 ,persia1 ,bagdad1 and crossed the great desert to ,palmyra and ,damascus1 where he got his first news of home1 and heard of his father's death fifteen years before4 ,diverging to ,hamath and ,aleppo1 on his return to ,damascus1 he found the ,black ,death raging1 so that two thousand four hundred died in one day4 ,revisiting ,jerusalem and ,cairo he made the haj a fourth time1 and finally reappeared at ,fez 7visiting ,sardinia en route7 on the #hth of ,november #acdi1 after twenty-four years' absence4 ,morocco1 he felt1 was1 after all1 the best of countries4 ,the dirhems of the ,west are but little2 but then you get more for them4 ,after going home to ,tangier1 ,ibn ,batuta crossed into ,spain and made the round of ,andalusia1 including ,gibraltar1 which had just then stood a siege from the ,roman tyrant ,adfunus 7,alphonso ,,xi4 of ,castile1 #acab-acej74 ,in #aceb the restless man started for ,central ,africa1 passing by the oases of the ,sahara 7where the houses were built of rock-salt1 as ,herodotus tells1 and roofed with camel skins7 to ,timbuktu and ,gogo on the ,niger1 a river which he calls the ,nile1 believing it to flow down into ,egypt1 an opinion maintained by some up to the date of ,lander's discovery4 ,being then recalled by his own king1 he returned to ,fez 7early in #aced7 via ,takadda1 ,haggar and ,tuat4 ,thus ended his twenty-eight years' wanderings which in their main lines alone exceeded #ge1jjj m4 ,by royal order he dictated his narrative to ,mahommed ,ibn ,juzai1 who concludes the work1 #acth of ,december #acee 7,a4,d47 with the declaration3 ,this ,shaykh is the traveller of our age2 and he who should call him the traveller of the whole body of ,islam would not exceed the truth4 ,ibn ,batuta died in #acgh1 aged seventy-three4 ,ibn ,batuta's travels have only been known in ,europe during the #aith century2 at first merely by ,arabic abridgments in the ,gotha and ,cambridge libraries4 ,notices or extracts had been published by ,seetzen 7c4 #ahjh71 ,kosegarten 7#ahah71 ,apetz 7#ahai71 and ,burckhardt 7#ahai71 when in #ahbi ,dr ,s4 ,lee published for the ,oriental ,translation ,fund a version from the abridged ,,mss4 at ,cambridge1 which attracted much interest4 ,the ,french capture of ,constantina afforded ,,mss4 of the complete work1 one of them the autograph of ,ibn ,juzai4 ,and from these1 after versions of fragments by various ,french scholars1 was derived at last 7#aheh-ahei7 the standard edition and translation of the whole by ,m4 ,dfrmery and ,dr ,sanguinetti1 in #d vols4 ,see also ,sir ,henry ,yule1 ,cathay1 ii4 #cig-ebf2 ,c4 ,raymond ,beazley1 ,dawn of ,modern ,geography1 iii4 #ece-ech4 ,though there are some singular chronological difficulties in the narrative1 and a good many cursory inaccuracies and exaggerations1 there is no part of it except1 perhaps1 certain portions of the journeys in north ,china1 which is open to doubt4 ,the accounts of the ,maldive ,islands1 and of the ,negro countries on the ,niger1 are replete with interesting and accurate particulars4 ,the former agrees surprisingly with that given by the only other foreign resident we know of1 ,pyrard de la ,val1 two hundred and fifty years later4 ,ibn ,batuta's statements and anecdotes regarding the showy virtues and solid vices of ,sultan ,muhammad ,tughlak are in entire agreement with ,indian historians1 and add many fresh details4 7,h4 ,y42 ,c4 ,r4 ,b47 ,,ibn ,,duraid ,abu ,bakr ,mahommed ibn ul-,hasan ibn ,duraid ul-,azdi 7#hcg-icd71 ,arabian poet and philologist1 was born at ,basra of south ,arabian stock4 ,at his native place he was trained under various teachers1 but fled in #hga to ,oman at the time ,basra was attacked by the negroes1 known as the ,zanj1 under ,muhallabi4 ,after living twelve years in ,oman he went to ,persia1 and1 under the protection of the governor1 ',abdallah ibn ,mahommed ibn ,mikal1 and his son1 ,isma'il1 wrote his chief works4 ,in #ibj he went to ,bagdad1 where he received a pension from the caliph ,moqtadir4 ,the ,maqsura1 a poem in praise of ,ibn ,mikal and his son1 has been edited by ,a4 ,haitsma 7#aggc7 ,e4 ,scheidius 7#aghf7 and ,n4 ,boyesen 7#ahbh74 ,various commentaries on the poem exist in ,,ms4 7cf4 ,c4 ,brockelmann1 ,gesch4 der ar4 ,lit41 i4 #baa ff41 ,weimar1 #ahih71 ,the ,jamhara fi-l-,lugha is a large dictionary written in ,persian but not printed4 ,another work is the ,kitab ul-,ishtiqaq 7,book of ,etymology71 edited by ,f4 ,wstenfeld 7,gttingen1 #ahed72 it was written in opposition to the anti-,arabian party to show the etymological connexion of the ,arabian tribal names4 7,g4 ,w4 ,t47 ,,ibn ,,faradi ,abu-l-,walid ',abdallah ibn ul-,faradi 7#ifb-ajab71 ,arabian historian1 was born at ,cordova and studied law and tradition4 ,in #iib he made the pilgrimage and proceeded to ,egypt and ,kairawan1 studying in these places4 ,after his return in #ajji he became cadi in ,valencia1 and was killed at ,cordova when the ,berbers took the city4 ,his chief work is the ,history of the ,learned ,men of ,andalusia1 edited by ,f4 ,codera 7,madrid1 #ahia-ahib74 ,he wrote also a history of the poets of ,andalusia4 7,g4 ,w4 ,t47 ,,ibn ,,farid ,abu-l-,qasim ',umar ibn ul-,farid 7#aaha-abce71 ,arabian poet1 was born in ,cairo1 lived for some time in ,mecca and died in ,cairo4 ,his poetry is entirely ,sufic1 and he was esteemed the greatest mystic poet of the ,arabs4 ,some of his poems are said to have been written in ecstasies4 ,his diwan has been published with commentary at ,beirut1 #ahhg1 c42 with the commentaries of ,burini 7d4 #afae7 and ',abdul-,ghani 7d4 #agcj7 at ,marseilles1 #ahec1 and at ,cairo2 and with the commentary of ,rushayyid ,ghalib 7#aith century7 at ,cairo1 #ahic4 ,one of the separate poems was edited by ,j4 von ,hammer ,purgstall as ,das arabische hohe ,lied der ,liebe 7,vienna1 #ahed74 ,see ,r4 ,a4 ,nicholson1 ,a ,literary ,history of the ,arabs 7,london1 #aijg71 pp4 #cid-cih4 7,g4 ,w4 ,t47 ,,ibn ,,gabirol ,,solomon ,,ben ,,judah1 ,jewish poet and philosopher1 was born at ,malaga1 probably about #ajba4 ,the early part of his troublous life was spent at ,saragossa1 but few personal details of it are recorded4 ,his parents died while he was a child and he was under the protection first of a certain ,jekuthiel1 who died in #ajci1 and afterwards of ,samuel ha-,nagid1 the well-known patron of learning4 ,his passionate disposition1 however1 embittered no doubt by his misfortunes1 involved him in frequent difficulties and led to his quarrelling with ,samuel4 ,it is generally agreed that he died young1 although the date is uncertain4 ,al ,harizi#a says at the age of twenty-nine1 and ,moses b4 ,ezra#b about thirty1 but ,abraham ,zaccuto#c states that he died 7at ,valencia7 in #ajgj4 ,m4 ,steinschneider#d accepts the date #ajeh4 ,his literary activity began early4 ,he is said to have composed poems at the age of sixteen1 and elegies by him are extant on ,hai ,gaon 7died in #ajch7 and ,jekuthiel 7died in #ajci71 each of which was written probably soon after the death of the person commemorated4 ,about the same time he also wrote his ',anaq1 a poem on grammar1 of which only #ig lines out of #djj are preserved4 ,moses ben ,ezra says of him that he imitated ,moslem models1 and was the first to open to ,jewish poets the door of versification1#e meaning that he first popularized the use of ,arabic metres in ,hebrew4 ,it is as a poet that he has been known to the ,jews to the present day1 and admired for the youthful freshness and beauty of his work1 in which he may be compared to the romantic school in ,france and ,england in the early #aith century4 ,besides his lyrical and satirical poems1 he contributed many of the finest compositions to the liturgy 7some of them with the acrostic ,shelomoh ha-qato71 which are widely different from the artificial manner of the earlier payyetanim4 ,the best known of his longer liturgical compositions are the philosophical ,kether ,malkuth 7for the ,day of ,atonement7 and the ,azharoth1 on the #fac precepts 7for ,shebhu'oth74 ,owing to his pure biblical style he had an abiding influence on subsequent liturgical writers4 ,outside the ,jewish community he was known as the philosopher ,avicebron 7,avencebrol1 ,avicebrol1 c47 ,the credit of identifying this name as a medieval corruption of ,ibn ,gabirol is due to ,s4 ,munk1 who showed that selections made by ,shem ,tobh ,palqera 7or ,falqera7 from the ,meqor ,hayyim 7the ,hebrew translation of an ,arabic original7 by ,ibn ,gabirol1 corresponded to the ,latin ,fons ,vitae of ,avicebron4 ,the ,latin version1 made by ,johannes ,hispalensis and ,gundisalvi about one hundred years after the author's death1 had at once become known among the ,schoolmen of the #abth century and exerted a powerful influence upon them1 although so little was known of the author that it was doubted whether he was a ,christian or a ,moslem4 ,the teaching of the ,fons ,vitae was entirely new to the country of its origin1 and being drawn largely from ,neoplatonic sources could not be expected to find favour with ,jewish thinkers4 ,its distinctive doctrines are3 7#a7 that all created beings1 spiritual or corporeal1 are composed of matter and form1 the various species of matter being but varieties of the universal matter1 and similarly all forms being contained in one universal form2 7#b7 that between the primal ,one and the intellect 7the ,greek3 nous of ,plotinus7 there is interposed the divine ,will1 which is itself divine and above the distinction of form and matter1 but is the cause of their union in the being next to itself1 the intellect1 in which ,avicebron holds that the distinction does exist4 ,the doctrine that there is a material1 as well as a formal1 element in all created beings was explicitly adopted from ,avicebron by ,duns ,scotus 7as against the view of ,albertus ,magnus and ,thomas ,aquinas71 and perhaps his exaltation of the will above the intellect is due to the same influence4 ,avicebron develops his philosophical system throughout quite independently of his religious views--a practice wholly foreign to ,jewish teachers1 and one which could not be acceptable to them4 ,indeed1 this charge is expressly brought against him by ,abraham ben ,david of ,toledo 7died in #aahj74 ,it is doubtless this non-religious attitude which accounts for the small attention paid to the ,fons ,vitae by the ,jews1 as compared with the wide influence of the philosophy of ,maimonides4 ,the other important work of ,ibn ,gabirol is ,islah al-akhlaq 7the improvement of character71 a popular work in ,arabic1 translated into ,hebrew 7,tiqqun middoth ha-nephesh7 by ,judah ibn ,tibbon4 ,it is widely different in treatment from the ,fons1 being intended as a practical not a speculative work4 ,the collection of moral maxims1 compiled in ,arabic but best known 7in the ,hebrew translation of ,judah ibn ,tibbon7 as ,mibhar ha-peninim1 is generally ascribed to ,ibn ,gabirol1 though on less certain grounds4 ,,bibliography4--,texts of the liturgical poems are to be found in the prayer-books3 others in ,dukes and ,edelmann1 ,treasures of ,oxford 7,oxford1 #ahej72 ,dukes1 ,shire ,shelomoh 7,hanover1 #aheh72 ,s4 ,sachs1 ,shir ha-shirim asher li-,shelomoh 7,paris1 #ahfh1 incomplete72 ,brody1 ,die weltlichen ,gedichte des 444 ,gabirol 7,berlin1 #ahig1 c474 ,avencebrolis ,fons ,vitae 7,latin text7 in ,clemens ,bumker's ,beitrge zur ,gesch4 d4 ,philosophie1 ,bd4 i4 ,hefte #b-d 7,mnster1 #ahib72 ,the ,improvement of the ,moral ,qualities ,arabic and ,english ed4 by ,s4 ,s4 ,wise 7,new ,york1 #aija72 ,a ,choice of ,pearls ,hebrew and ,english ed4 by ,ascher 7,london1 #ahei74 ,on the philosophy in general3 ,s4 ,munk1 ,mlanges 7quoted above72 ,guttmann1 ,die ,philosophie des ,sal4-ibn ,gabirol 7,gttingen1 #ahhi72 ,d4 ,kaufmann1 ,studien ber ,sal4-ibn ,gabirol 7,budapest1 #ahii72 ,s4 ,horovitz1 ,die ,psychologie ,ibn ,gabirols1 in the ,jahresbericht des jd4 theol4 ,seminars ,frnckel'scher ,stiftung 7,breslau1 #aijj72 ,wittmann1 ,zur ,stellung ,avencebrols 444 7in ,bumker's ,beitrge1 ,bd4 v4 ,heft #a1 ,mnster1 #aije74 7,a4 ,cy47 ,,footnotes3 #a ,jud4 ,har4 ,macam1 ed4 ,lagarde 7,gttingen1 #ahhc71 p4 #hi1 l4 #fa4 #b ,see the passage quoted by ,munk1 ,mlanges de philosophie arabe et juive 7,paris1 #ahei71 pp4 #bfd and #eag4 #c ,liber ,juchassin1 ed4 ,filipowski 7,london1 #aheg71 p4 #bag4 #d ,hebr4 bersetzungen 7,berlin1 #ahic71 #bai1 note #gj2 cf4 ,kaufmann1 ,studien ber ,sal4-ibn ,gabirol 7,budapest1 #ahii71 p4 #gi1 note #b4 #e ,see ,munk1 op4 cit4 pp4 #eae-eaf1 transl4 on pp4 #bfc-bfd4 ,metre had been already used by ,dunash4 ,,ibn ,,haukal1 strictly ,,ibn ,,hauqal1 a #ajth century ,arabian geographer4 ,nothing is known of his life4 ,his work on geography1 written in #igg1 is only a revision and extension of the ,masalik ul-,mamalik of al-,istakhri1 who wrote in #iea4 ,this itself was a revised edition of the ,kitab ul-,ashkal or ,suwar ul-,aqalim of ,abu ,zaid ul-,balkhi1 who wrote about #iba4 ,ibn ,haukal's work was published by ,m4 ,j4 de ,goeje 7,leiden1 #ahgc74 ,an anonymous epitome of the book was written in #abcc4 ,see ,m4 ,j4 de ,goeje1 ,die ,istahri-,balhi ,frage1 in the ,zeitschrift der deutschen ,morgenlndischen ,gesellschaft1 xxv4 #db sqq4 ,,ibn ,,hazm ,abu ,mahommed ',ali ibn ,ahmad ibn ,hazm 7#iid-ajfd71 ,moslem theologian1 was born in a suburb of ,cordova4 ,he studied history1 law and theology1 and became a vizier as his father had been before him1 but was deposed for heresy1 and spent the rest of his life quietly in the country4 ,in legal matters he belonged first to the ,shafi'ite school1 but came to adopt the views of the ,zahirites1 who admitted only the external sense of the ,koran and tradition1 disallowing the use of analogy 7,qiyas7 and ,taqlid 7appeal to the authority of an imam71 and objecting altogether to the use of individual opinion 7,ra'y74 ,every sentence of the ,koran was to be interpreted in a general and universal sense2 the special application to the circumstances of the time it was written was denied4 ,every word of the ,koran was to be taken in a literal sense1 but that sense was to be learned from other uses in the ,koran itself1 not from the meaning in other literature of the time4 ,the special feature of ,ibn ,hazm's teaching was that he extended the application of these principles from the study of law to that of dogmatic theology4 ,he thus found himself in opposition at one time to the ,mo'tazilites1 at another to the ,ash'arites4 ,he did not1 however1 succeed in forming a school4 ,his chief work is the ,kitab ul-,milal wan-,nihal1 or ,book of ,sects 7published in ,cairo1 #ahii74 ,for his teaching cf4 ,i4 ,goldziher1 ,die ,zahiriten1 pp4 #aaf-agb 7,leipzig1 7#ahhd71 and ,m4 ,schreiner in the ,journal of the ,german ,oriental ,society1 lii4 #dfd-dhf4 ,for a list of his other works see ,c4 ,brockelmann's ,geschichte der arabischen ,literatur1 vol4 i4 7,weimar1 #ahih71 p4 #djj4 7,g4 ,w4 ,t47 ,,ibn ,,hisham ,abu ,mahommed ',abdulmalik ibn ,hisham ibn ,ayyub ul-,himyari 7d4 #hcd71 ,arabian biographer1 studied in ,kufa but lived afterwards in ,fostat 7old ,cairo71 where he gained a name as a grammarian and student of language and history4 ,his chief work is his edition of ,ibn ,ishaq's 7q4v47 ,life of the ,apostle of ,god1 which has been edited by ,f4 ,wstenfeld 7,gttingen1 #aheh-ahfj74 ,an abridged ,german translation has been made by ,g4 ,weil 7,stuttgart1 #ahfd2 cf4 ,p4 ,brnnle1 ,die ,commentatoren des ,ibn ,ishaq und ihre ,scholien1 ,halle1 #ahie74 ,ibn ,hisham is said to have written a work explaining the difficult words which occur in poems on the life of the ,apostle1 and another on the genealogies of the ,himyarites and their princes4 7,g4 ,w4 ,t47 ,,ibn ,,ishaq ,mahommed ibn ,ishaq ,abu ',abdallah 7d4 #gfh71 ,arabic historian1 lived in ,medina1 where he interested himself to such an extent in the details of the ,prophet's life that he was attacked by those to whom his work seemed to have a rationalistic tendency4 ,he consequently left ,medina in #gcc1 and went to ,alexandria1 then to ,kufa and ,hira1 and finally to ,bagdad1 where the caliph ,mansur provided him with the means of writing his great work4 ,this was the ,life of the ,apostle of ,god1 which is now lost and is known to us only in the recension of ,ibn ,hisham 7q4v474 ,the work has been attacked by ,arabian writers 7as in the ,fihrist7 as untrustworthy1 and it seems clear that he introduced forged verses 7cf4 ,journal of the ,german ,oriental ,society1 xiv4 #bhh sqq474 ,it remains1 however1 one of the most important works of the age4 7,g4 ,w4 ,t47 ,,ibn ,,jubair ,abu-l ,husain ,mahommed ibn ,ahmad ibn ,jubair 7#aade-abag71 ,arabian geographer1 was born in ,valencia4 ,at ,granada he studied the ,koran1 tradition1 law and literature1 and later became secretary to the ,mohad governor of that city4 ,during this time he composed many poems4 ,in #aahc he left the court and travelled to ,alexandria1 ,jerusalem1 ,medina1 ,mecca1 ,damascus1 ,mosul and ,bagdad1 returning in #aahe by way of ,sicily4 ,the ,travels of ,ibn ,jubair were edited by ,w4 ,wright 7,leiden1 #aheb72 and a new edition of this text1 revised by ,m4 ,j4 de ,goeje1 was published by the ,gibb ,trustees 7,london1 #aijg74 ,the part relating to ,sicily was published1 with ,french translation and notes1 by ,m4 ,amari in the ,journal asiatique 7#ahde-ahdf7 and a ,french translation alone of the same part by ,g4 ,crolla in ,museon1 vi4 #abc-acb4 7,g4 ,w4 ,t47 ,,ibn ,,khaldun ,abu ,zaid ibn ,mahommed ibn ,mahommed ibn ,khaldun 7#accb-adjf71 ,arabic historian1 was born at ,tunis4 ,he studied the various branches of ,arabic learning with great success4 ,in #aceb he obtained employment under the ,marinid sultan ,abu ,inan 7,faris ,i47 at ,fez4 ,in the beginning of #acef1 his integrity having been suspected1 he was thrown into prison until the death of ,abu ,inan in #aceh1 when the vizier al-,hasan ibn ,omar set him at liberty and reinstated him in his rank and offices4 ,he here continued to render great service to ,abu ,salem 7,ibrahim ,,iii471 ,abu ,inan's successor1 but1 having offended the prime minister1 he obtained permission to emigrate to ,spain1 where1 at ,granada1 he was received with great cordiality by ,ibn al ,ahmar1 who had been greatly indebted to his good offices when an exile at the court of ,abu ,salem4 ,the favours he received from the sovereign excited the jealousy of the vizier1 and he was driven back to ,africa 7#acfd71 where he was received with great cordiality by the sultan of ,bougie1 ,abu ,abdallah1 who had been formerly his companion in prison4 ,on the fall of ,abu ,abdallah ,ibn ,khaldun raised a large force amongst the desert ,arabs1 and entered the service of the sultan of ,tlemen4 ,a few years later he was taken prisoner by ,abdalaziz 7',abd ul ',aziz71 who had defeated the sultan of ,tlemen and seized the throne4 ,he then entered a monastic establishment1 and occupied himself with scholastic duties1 until in #acgj he was sent for to ,tlemen by the new sultan4 ,after the death of ',abd ul ',aziz he resided at ,fez1 enjoying the patronage and confidence of the regent4 ,after some further vicissitudes in #acgh he entered the service of the sultan of his native town of ,tunis1 where he devoted himself almost exclusively to his studies and wrote his history of the ,berbers4 ,having received permission to make the pilgrimage to ,mecca1 he reached ,cairo1 where he was presented to the sultan1 al-,malik udh-,dhahir ,barkuk1 who insisted on his remaining there1 and in the year #achd made him grand cadi of the ,malikite rite for ,cairo4 ,this office he filled with great prudence and probity1 removing many abuses in the administration of justice in ,egypt4 ,at this time the ship in which his wife and family1 with all his property1 were coming to join him1 was wrecked1 and every one on board lost4 ,he endeavoured to find consolation in the completion of his history of the ,arabs of ,spain4 ,at the same time he was removed from his office of cadi1 which gave him more leisure for his work4 ,three years later he made the pilgrimage to ,mecca1 and on his return lived in retirement in the ,fayum until #acii1 when he was again called upon to resume his functions as cadi4 ,he was removed and reinstated in the office no fewer than five times4 ,in #adjj he was sent to ,damascus1 in connexion with the expedition intended to oppose ,timur or ,tamerlane4 ,when ,timur had become master of the situation1 ,ibn ,khaldun let himself down from the walls of the city by a rope1 and presented himself before the conqueror1 who permitted him to return to ,egypt4 ,ibn ,khaldun died on the #afth of ,march #adjf1 at the age of sixty-four4 ,the great work by which he is known is a ,universal ,history1 but it deals more particularly with the history of the ,arabs of ,spain and ,africa4 ,its ,arabic title is ,kitab ul',ibar1 wa diwan el ,mubtada wa'l ,khabar1 fi ayyam ul ',arab wa'l',ajam wa'l ,berber2 that is1 ,the ,book of ,examples and the ,collection of ,origins and ,information respecting the ,history of the ,arabs1 ,foreigners and ,berbers4 ,it consists of three books1 an introduction and an autobiography4 ,book i4 treats of the influence of civilization upon man2 book ii4 of the history of the ,arabs and other peoples from the remotest antiquity until the author's own times2 book iii4 of the history of the ,berber tribes and of the kingdoms founded by that race in ,north ,africa4 ,the introduction is an elaborate treatise on the science of history and the development of society1 and the autobiography contains the history1 not only of the author himself1 but of his family and of the dynasties which ruled in ,fez1 ,tunis and ,tlemen during his lifetime4 ,an edition of the ,arabic text has been printed at ,bulaq1 7#g vols41 #ahfg7 and a part of the work has been translated by the late ,baron ,mc,g4 de ,slane under the title of ,histoire des ,berbres 7,algiers1 #aheb-ahef72 it contains an admirable account of the author and analysis of his work4 ,vol4 i41 the ,muqaddama 7preface71 was published by ,m4 ,quatremre 7#c vols41 ,paris1 #aheh71 often republished in the ,east1 and a ,french translation was made by ,mc,g4 de ,slane 7#c vols41 ,paris1 #ahfb-ahfh74 ,the parts of the history referring to the expeditions of the ,franks into ,moslem lands were edited by ,c4 ,j4 ,tornberg 7,upsala1 #ahdj71 and the parts treating of the ,banu-l ,ahmar kings of ,granada were translated into ,french by ,m4 ,gaudefroy-,demombynes in the ,journal asiatique1 ser4 #i1 vol4 xiii4 ,the ,autobiography of ,ibn ,khaldun was translated into ,french by de ,slane in the ,journal asiatique1 ser4 #d1 vol4 iii4 ,for an ,english appreciation of the philosophical spirit of ,ibn ,khaldun see ,r4 ,flint's ,history of the ,philosophy of ,history 7,edinburgh1 #ahic71 pp4 #aeg-agj4 7,e4 ,h4 ,p42 ,g4 ,w4 ,t47 ,,ibn ,,khallikan ,abu-l ',abbas ,ahmad ibn ,khallikan 7#abaa-abhb71 ,arabian biographer1 was born at ,arbela1 the son of a professor reputed to be ascended from the ,barmecides of the court of ,harun al-,rashid4 ,when eighteen he went to ,aleppo1 where he studied for six years1 then to ,damascus1 and in #abch to ,alexandria and ,cairo4 ,in #abeb he married and became chief cadi of ,syria in ,damascus in #abfa4 ,having held this office for ten years1 he was professor in ,cairo until #abgh1 when he again took office in ,damascus for three years4 ,in #abha he accepted a professorship in the same city1 but died in the following year4 ,his great work is the ,kitab ,wafayat ul-,a'yan1 ,the ,obituaries of ,eminent ,men4 ,it contains in alphabetical order the lives of the most celebrated persons of ,moslem history and literature1 except those of ,mahomet1 the four caliphs and the companions of ,mahomet and their followers 7the ,tabiun74 ,the work is anecdotal and contains many brief extracts from the poetry of the writers4 ,it was published by ,f4 ,wstenfeld 7,gttingen1 #ahce-ahdc71 in part by ,mc,g4 de ,slane 7,paris1 #ahch-ahdb71 and also in ,cairo 7#ahei and #ahhb74 ,an ,english translation by ,mc,g4 de ,slane was published for the ,oriental ,translation ,fund in #d vols4 7,london1 #ahdb-ahga74 ,thirteen extra biographies from a manuscript in ,amsterdam were published by ,pijnappel 7,amsterdam1 #ahde74 ,a ,persian translation exists in manuscript1 and various extracts from the work are known4 ,several supplements to the book have been written1 the best known being that of ,mahommed ibn ,shakir 7d4 #acfb71 published at ,cairo #ahhb4 ,a collection of poems by ,ibn ,khallikan is also extant4 7,g4 ,w4 ,t47 ,,ibn ,,qutaiba1 or ,,kotaiba ,abu ,mahommed ibn ,muslim ibn ,qutaiba 7#hbh-hhi71 ,arabian writer1 was born at ,bagdad or ,kufa1 and was of ,iranian descent1 his father belonging to ,merv4 ,having studied tradition and philology he became cadi in ,dinawar and afterwards teacher in ,bagdad1 where he died4 ,he was the first representative of the eclectic school of ,bagdad philologists that succeeded the schools of ,kufa and ,basra 7see ,,arabia3 ,literature1 section ,grammar74 ,although engaged also in theological polemic 7cf4 ,i4 ,goldziher1 ,muhammedanische ,studien1 ii4 #acf1 ,halle1 #ahij71 his chief works were directed to the training of the ideal secretary4 ,of these five may be said to form a series4 ,the ,adab ul-,katib 7,training of the ,secretary7 contains instruction in writing and is a compendium of ,arabic style4 ,it has been edited by ,max ,grnert 7,leiden1 #aijj74 ,the ,kitab ush-,sharab is still in manuscript4 ,the ,kitab ul-,ma'arif has been edited by ,f4 ,wstenfeld as the ,handbuch der ,geschichte#a 7,gttingen1 #ahej72 the ,kitab ush-,shi'r wash-,shu'arai 7,book of ,poetry and ,poets7 edited by ,m4 ,j4 de ,goeje 7,leiden1 #aijd74b ,the fifth and most important is the ',uyun ul-,akhbar1 which deals in ten books with lordship1 war1 nobility1 character1 science and eloquence1 asceticism1 friendship1 requests1 foods and women1 with many illustrations from history1 poetry and proverb 7ed4 ,c4 ,brockelmann1 ,leiden1 #aijj sqq474 ,for other works 7which were much quoted by later ,arabian writers7 see ,c4 ,brockelmann1 ,gesch4 der arabischen ,literatur1 vol4 i4 7,weimar1 #ahih71 pp4 #abj-abb4 7,g4 ,w4 ,t47 ,,footnotes3 #a ,summary in ,e4 ,g4 ,browne1 ,a ,literary ,history of ,persia 7,london1 #aijb71 pp4 #chg f4 #b ,the preface was translated into ,german by ,theodor ,nldeke in his ,beitrge 7,hanover1 #ahfd71 pp4 #a-ea4 ,,ibn ,,sa',d ,abu ',abdallah ,mahommed ibn ,sa'd ibn ,mani' uz-,zuhri1 often called ,katib ul-,waqidi 7secretary of ,waqidi7 of ,basra 7d4 #hde71 ,arabian biographer1 received his training in tradition from ,waqidi and other celebrated teachers4 ,he lived for the most part in ,bagdad1 and had the reputation of being both trustworthy and accurate in his writings1 which1 in consequence1 were much used by later writers4 ,his work1 the ,kitab ul-,tabaqat ul-,kabir 7#ae vols47 contains the lives of ,mahomet1 his ,companions and ,helpers 7including those who fought at ,badr as a special class7 and of the following generation 7the ,followers7 who received their traditions from the personal friends of the ,prophet4 ,this work has been edited under the superintendence of ,e4 ,sachau 7,leiden1 #aijd sqq472 cf4 ,o4 ,loth1 ,das ,classenbuch des ,ibn ,sa'd 7,leipzig1 #ahfi74 7,g4 ,w4 ,t47 ,,ibn ,,tibbon1 a family of ,jewish translators1 who flourished in ,provence in the #abth and #acth centuries4 ,they all made original contributions to philosophical and scientific literature1 but their permanent fame is based on their translations4 ,between them they rendered into ,hebrew all the chief ,jewish writings of the middle ages4 ,these ,hebrew translations were1 in their turn1 rendered into ,latin 7by ,buxtorf and others7 and in this form the works of ,jewish authors found their way into the learned circles of ,europe4 ,the chief members of the ,ibn ,tibbon family were 7#a7 ,,judah ,,ben ,,saul 7#aabj-aaij71 who was born in ,spain but settled in ,lunel4 ,he translated the works of ,bahya1 ,halevi1 ,saadiah and the grammatical treatises of ,janah4 7#b7 ,his son1 ,,samuel 7#aaej-abcj71 translated the ,guide of the ,perplexed by ,maimonides4 ,he justly termed his father the father of the ,translators1 but ,samuel's own method surpassed his father's in lucidity and fidelity to the original4 7#c7 ,son of ,samuel1 ,,moses 7died #abhc74 ,he translated into ,hebrew a large number of ,arabic books 7including the ,arabic form of ,euclid74 ,the ,ibn ,tibbon family thus rendered conspicuous services to ,european culture1 and did much to further among ,jews who did not understand ,arabic the study of science and philosophy4 7,i4 ,a47 ,,ibn ,,tufail1 or ,,tofail ,abu ,bakr ,mahommed ibn ',abd-ul-,malik ibn ,tufail ul-,qaisi 7d4 #aahe71 ,moslem philosopher1 was born at ,guadix near ,granada4 ,there he received a good training in philosophy and medicine1 and is said to have been a pupil of ,avempace 7q4v474 ,he became secretary to the governor of ,granada1 and later physician and vizier to the ,mohad caliph1 ,abu ,ya'qub ,yusuf4 ,he died at ,morocco4 ,his chief work is a philosophical romance1 in which he describes the awakening and growth of intellect in a child removed from the influences of ordinary life4 ,its ,arabic title is ,risalat ,hayy ibn ,yaqzan2 it was edited by ,e4 ,pococke as ,philosophus autodidactus 7,oxford1 #afga2 #bnd ed41 #agjj71 and with a ,french translation by ,l4 ,gauthier 7,algiers1 #aijj74 ,an ,english translation by ,s4 ,ockley was published in #agjh and has been reprinted since4 ,a ,spanish translation by ,f4 ,pons ,boigues was published at ,saragossa 7#aijj74 ,another work of ,ibn ,tufail1 the ,kitab ,asrar ul-,hikma ul-mashraqiyya 7,secrets of ,eastern ,science71 was published at ,bulaq 7#ahhb72 cf4 ,s4 ,munk1 ,mlanges 7#ahei71 pp4 #daj sqq41 and ,t4 ,j4 de ,boer1 ,geschichte der ,philosophie im ,islam 7,stuttgart1 #aija71 pp4 #afj sqq4 7also an ,english translation74 7,g4 ,w4 ,t47 ,,ibn ,,usaibi',a ,muwaffaquddin ,abu-l-',abbas ,ahmad ibn ul-,qasim ibn ,abi ,usaibi'a 7#abjc-abgj71 ,arabian physician1 was born at ,damascus1 the son of an oculist1 and studied medicine at ,damascus and ,cairo4 ,in #abcf he was appointed by ,saladin physician to a new hospital in ,cairo1 but surrendered the appointment the following year to take up a post given him by the amir of ,damascus in ,salkhad near that city4 ,there he lived and died4 ,he wrote ',uyun ul-,anba'fi ,tabaqat ul-,atibba' or ,lives of the ,physicians1 which in its first edition 7#abde-abdf7 was dedicated to the vizier of ,damascus4 ,this he enlarged1 though it is uncertain whether the new edition was made public in the lifetime of the author4 ,edition by ,a4 ,mller 7,knigsberg1 #ahhd74 7,g4 ,w4 ,t47 ,,ibo1 a district of ,british ,west ,africa1 on the lower ,niger immediately above the delta1 and mainly on the eastern bank of the river4 ,the chief town1 frequently called by the same name 7more correctly ,abo or boh71 lies on a creek which falls into the main stream about #aej m4 from its mouth and contains from #fjjj to #hjjj inhabitants4 ,the ,ibo are a strong well-built ,negro race4 ,their women are distinguished by their embonpoint4 ,the language of the ,ibo is one of the most widely spoken on the lower ,niger4 ,the ,rev4 ,j4 ,f4 ,schn began its reduction in #ahda1 and in #ahfa he published a grammar 7,oku ,ibo ,grammatical ,elements1 ,london1 ,church ,miss4 ,soc474 7,see ,,nigeria47 ,,ibrahim ,,al-,,mausili 7#gdb-hjd71 ,arabian singer1 was born of ,persian parents settled in ,kufa4 ,in his early years his parents died and he was trained by an uncle4 ,singing1 not study1 attracted him1 and at the age of twenty-three he fled to ,mosul1 where he joined a band of wild youths4 ,after a year he went to ,rai 7,rei1 ,rhagae71 where he met an ambassador of the caliph ,mansur1 who enabled him to come to ,basra and take singing lessons4 ,his fame as a singer spread1 and the caliph ,mahdi brought him to the court4 ,there he remained a favourite under ,hadi1 while ,harun al-,rashid kept him always with him until his death1 when he ordered his son 7,ma'mun7 to say the prayer over his corpse4 ,ibrahim1 as might be expected1 was no strict ,moslem4 ,two or three times he was knouted and imprisoned for excess in wine-drinking1 but was always taken into favour again4 ,his powers of song were far beyond anything else known at the time4 ,two of his pupils1 his son ,ishaq and ,muhariq1 attained celebrity after him4 ,see the ,preface to ,w4 ,ahlwardt's ,abu ,nowas 7,greifswald1 #ahfa71 pp4 #ac-ah1 and the many stories of his life in the ,kitab ul-,aghani1 v4 #b-di4 7,g4 ,w4 ,t47 ,,ibrahim ,,pasha 7#aghi-ahdh71 ,egyptian general1 is sometimes spoken of as the adopted son of ,mehemet ,ali1 pasha of ,egypt4 ,he is also and more commonly called his son4 ,he was born in his father's native town1 ,kavala in ,thrace4 ,during his father's struggle to establish himself in ,egypt1 ,ibrahim1 then sixteen years of age1 was sent as a hostage to the ,ottoman capitan pasha 7admiral71 but when ,mehemet ,ali was recognized as pasha1 and had defeated the ,english expedition under ,general ,a4 ,m4 ,fraser1 he was allowed to return to ,egypt4 ,when ,mehemet ,ali went to ,arabia to prosecute the war against the ,wahhabis in #ahac1 ,ibrahim was left in command in ,upper ,egypt4 ,he continued the war with the broken power of the ,mamelukes1 whom he suppressed4 ,in #ahaf he succeeded his brother ,tusun in command of the ,egyptian forces in ,arabia4 ,mehemet ,ali had already begun to introduce ,european discipline into his army1 and ,ibrahim had probably received some training1 but his first campaign was conducted more in the old ,asiatic style than his later operations4 ,the campaign lasted two years1 and terminated in the destruction of the ,wahhabis as a political power4 ,ibrahim landed at ,yembo1 the port of ,medina1 on the #cjth of ,september #ahaf4 ,the holy cities had been recovered from the ,wahhabis1 and ,ibrahim's task was to follow them into the desert of ,nejd and destroy their fortresses4 ,such training as the ,egyptian troops had received1 and their artillery1 gave them a marked superiority in the open field4 ,but the difficulty of crossing the desert to the ,wahhabi stronghold of ,deraiya1 some #djj m4 east of ,medina1 and the courage of their opponents1 made the conquest a very arduous one4 ,ibrahim displayed great energy and tenacity1 sharing all the hardships of his army1 and never allowing himself to be discouraged by failure4 ,by the end of ,september #ahah he had forced the ,wahhabi leader to surrender1 and had taken ,deraiya1 which he ruined4 ,on the #aath of ,december #ahai he made a triumphal entry into ,cairo4 ,after his return he gave effective support to the ,frenchman1 ,colonel ,sve 7,suleiman ,pasha71 who was employed to drill the army on the ,european model4 ,ibrahim set an example by submitting to be drilled as a recruit4 ,when in #ahbd ,mehemet ,ali was appointed governor of the ,morea by the sultan1 who desired his help against the insurgent ,greeks1 he sent ,ibrahim with a squadron and an army of #ag1jjj men4 ,the expedition sailed on the #ajth of ,july #ahbd1 but was for some months unable to do more than come and go between ,rhodes and ,crete4 ,the fear of the ,greek fire ships stopped his way to the ,morea4 ,when the ,greek sailors mutinied from want of pay1 he was able to land at ,modon on the #bfth of ,february #ahbe4 ,he remained in the ,morea till the capitulation of the #ast of ,october #ahbh was forced on him by the intervention of the ,western powers4 ,ibrahim's operations in the ,morea were energetic and ferocious4 ,he easily defeated the ,greeks in the open field1 and though the siege of ,missolonghi proved costly to his own troops and to the ,turks who operated with him1 he brought it to a successful termination on the #bdth of ,april #ahbf4 ,the ,greek guerrilla bands harassed his army1 and in revenge he desolated the country and sent thousands of the inhabitants into slavery in ,egypt4 ,these measures of repression aroused great indignation in ,europe1 and led first to the intervention of the ,english1 ,french and ,russian squadrons 7see ,,navarino1 ,,battle ,,of71 and then to the landing of a ,french expeditionary force4 ,by the terms of the capitulation of the #ast of ,october #ahbh1 ,ibrahim evacuated the country4 ,it is fairly certain that the ,turkish government1 jealous of his power1 had laid a plot to prevent him and his troops from returning to ,egypt4 ,english officers who saw him at ,navarino describe him as short1 grossly fat and deeply marked with smallpox4 ,his obesity did not cause any abatement of activity when next he took the field4 ,in #ahca1 his father's quarrel with the ,porte having become flagrant1 ,ibrahim was sent to conquer ,syria4 ,he carried out his task with truly remarkable energy4 ,he took ,acre after a severe siege on the #bgth of ,may #ahcb1 occupied ,damascus1 defeated a ,turkish army at ,homs on the #hth of ,july1 defeated another ,turkish army at ,beilan on the #bith of ,july1 invaded ,asia ,minor1 and finally routed the grand vizier at ,konia on the #bast of ,december4 ,the convention of ,kutaiah on the #fth of ,may left ,syria for a time in the hands of ,mehemet ,ali4 ,ibrahim was undoubtedly helped by ,colonel ,sve and the ,european officers in his army1 but his intelligent docility to their advice1 as well as his personal hardihood and energy1 compare most favourably with the sloth1 ignorance and arrogant conceit of the ,turkish generals opposed to him4 ,he is entitled to full credit for the diplomatic judgment and tact he showed in securing the support of the inhabitants1 whom he protected and whose rivalries he utilized4 ,after the campaign of #ahcb and #ahcc ,ibrahim remained as governor in ,syria4 ,he might perhaps have administered successfully1 but the exactions he was compelled to enforce by his father soon ruined the popularity of his government and provoked revolts4 ,in #ahch the ,porte felt strong enough to renew the struggle1 and war broke out once more4 ,ibrahim won his last victory for his father at ,nezib on the #bdth of ,june #ahci4 ,but ,great ,britain and ,austria intervened to preserve the integrity of ,turkey4 ,their squadrons cut his communications by sea with ,egypt1 a general revolt isolated him in ,syria1 and he was finally compelled to evacuate the country in ,february #ahda4 ,ibrahim spent the rest of his life in peace1 but his health was ruined4 ,in #ahdf he paid a visit to western ,europe1 where he was received with some respect and a great deal of curiosity4 ,when his father became imbecile in #ahdh he held the regency till his own death on the #ajth of ,november #ahdh4 ,see ,edouard ,gouin1 ,l'gypte au ,,xixe sicle 7,paris1 #ahdg72 ,aim ,vingtrinier1 ,soliman-,pasha 7,colonel ,sve7 7,paris1 #ahhf74 ,a great deal of unpublished material of the highest interest with regard to ,ibrahim's personality and his system in ,syria is preserved in the ,british ,foreign ,office archives2 for references to these see ,cambridge ,mod4 ,hist4 x4 #heb1 bibliography to chap4 xvii4 ,,ibsen1 ,,henrik 7#ahbh-aijf71 ,norwegian dramatic and lyric poet1 eldest son of ,knud ,henriksen ,ibsen1 a merchant1 and of his wife ,marichen ,cornelia ,altenburg1 was born at ,skien on the #bjth of ,march #ahbh4 ,for five generations the family had consisted on the father's side of a blending of the ,danish1 ,german and ,scottish races1 with no intermixture of pure ,norwegian4 ,in #ahcf ,knud ,ibsen became insolvent1 and the family withdrew1 in great poverty1 to a cottage in the outskirts of the town4 ,after brief schooling at ,skien1 ,ibsen was1 towards the close of #ahdc1 apprenticed to an apothecary in ,grimstad2 here he remained through seven dreary years of drudgery1 which set their mark upon his spirit4 ,in #ahdg1 in his nineteenth year1 he began to write poetry4 ,he made a gloomy and almost sinister impression upon persons who met him at this time1 and one of his associates of those days has recorded that ,ibsen walked about ,grimstad like a mystery sealed with seven seals4 ,he had continued1 by assiduous reading1 his self-education1 and in #ahej he contrived to come up as a student to ,christiania4 ,in the same year he published his first work1 the blank-verse tragedy of ,catilina1 under the pseudonym ,brynjolf ,bjarme4 ,a second drama1 ,the ,viking's ,barrow1 was acted 7but not printed7 a few months later2 ,ibsen was at this time entirely under the influence of the ,danish poet ,oehlenschlger4 ,during the next year or two he made a very precarious livelihood in ,christiania as a journalist1 but in ,november #ahea he had the good fortune to be appointed stage-poet at the little theatre of ,bergen1 with a small but regular salary4 ,he was practically manager at this house1 and he also received a travelling stipend4 ,in #aheb1 therefore1 he went for five months to study the stage1 to ,copenhagen and to ,dresden4 ,among many dramatic experiments which ,ibsen made in ,bergen1 the most considerable and most satisfactory is the saga-drama of ,mistress ,inger at straat1 which was produced in #ahee2 and printed at ,christiania in #aheg2 here are already perceptible some qualities of his mature character4 ,much less significant1 although at the time more successful1 is ,the ,feast at ,solhaug1 a tragedy produced in ,bergen in #ahef2 here for a moment ,ibsen abandoned his own nascent manner for an imitation of the popular romantic dramatist of ,denmark1 ,henrik ,hertz4 ,it is noticeable that ,ibsen1 by far the most original of modern writers for the stage1 was remarkably slow in discovering the true bent of his genius4 ,his next dramatic work was the romantic tragedy of ,olaf ,liljekrans1 performed in #aheg1 but unprinted until #ahih4 ,this was the last play ,ibsen wrote in ,bergen4 ,in the summer of the former year his five years' appointment came to an end1 and he returned to ,christiania4 ,almost immediately he began the composition of a work which showed an extraordinary advance on all that he had written before1 the beautiful saga-drama of ,the ,warriors in ,helgeland1 in which he threw off completely the influence of the ,danish romantic tragedians1 and took his material directly from the ancient ,icelandic sources4 ,this play marks an epoch in the development of ,norwegian literature4 ,it was received by the managers1 both in ,christiania and ,copenhagen1 with contemptuous disapproval1 and in the autumn of #aheg ,ibsen could not contrive to produce it even at the new theatre of which he was now the manager4 ,the ,warriors was printed at ,christiania in #aheh1 but was not acted anywhere until #ahfa4 ,during these years ,ibsen suffered many reverses and humiliations1 but he persisted in his own line in art4 ,some of his finest short poems1 among others the admirable seafaring romance1 ,terje ,vigen1 belong to the year #ahfj4 ,the annoyances which ,ibsen suffered1 and the retrograde and ignorant conditions which he felt around him in ,norway1 developed the ironic qualities in his genius1 and he became an acid satirist4 ,the brilliant rhymed drama1 ,love's ,comedy1 a masterpiece of lyric wit and incisive vivacity1 was published in #ahfb4 ,this was a protest against the conventionality which deadens the beauty of all the formal relations between men and women1 and against the pettiness1 the publicity1 and the prosiness of betrothed and married life among the middle classes in ,norway2 it showed how society murders the poetry of love4 ,for some time past ,ibsen had been meditating another saga-drama in prose1 and in #ahfd this appeared1 ,kongsemnerne 7,the ,pretenders74 ,these works1 however1 now so universally admired1 contained an element of strangeness which was not welcome when they were new4 ,ibsen's position in ,christiania grew more and more disagreeable1 and he had positive misfortunes which added to his embarrassment4 ,in #ahfb his theatre became bankrupt1 and he was glad to accept the poorly-paid post of aesthetic adviser at the other house4 ,an attempt to obtain a poet's pension 7digtergage7 was unsuccessful2 the ,storthing1 which had just voted one to ,bjrnson1 refused to do the same for ,ibsen4 ,his cup was full of disillusion and bitterness1 and in ,april #ahfd he started1 by ,berlin and ,trieste1 ultimately to settle in ,rome4 ,his anger and scorn gave point to the satirical arrows which he shot back to his thankless fatherland from ,italy in the splendid poem of ,brand1 published in ,copenhagen in #ahff1 a fierce attack on the ,laodicean state of religious and moral sentiment in the ,norway of that day2 the central figure1 the stern priest ,brand1 who attempts to live like ,christ and is snubbed and hounded away by his latitudinarian companions1 is one of the finest conceptions of a modern poet4 ,ibsen had scarcely closed ,brand before he started a third lyrico-dramatic satire4 ,peer ,gynt 7#ahfg71 which remains1 in a technical sense1 the most highly finished of all his metrical works4 ,in ,brand the hero had denounced certain weaknesses which ,ibsen saw in the ,norwegian character1 but these and other faults are personified in the hero of ,peer ,gynt2 or rather1 in this figure the poet pictured1 in a type1 the ,norwegian nation in all the egotism1 vacillation1 and lukewarmness which he believed to be characteristic of it4 ,ibsen1 however1 acted better than he preached1 and he soon forgot his abstraction in the portrait of ,peer ,gynt as a human individual4 ,in this magnificent work modern ,norwegian literature first rises to a level with the finest ,european poetry of the century4 ,in #ahfi ,ibsen wrote the earliest of his prose dramas1 the political comedy1 ,the ,young ,men's ,league1 in which for the first time he exercised his extraordinary gift for perfectly natural and yet pregnant dialogue4 ,ibsen was in ,egypt1 in ,october #ahfi1 when his comedy was put on the stage in ,christiania1 amid violent expressions of hostility2 on hearing the news1 he wrote his brilliant little poem of defiance1 called ,at ,port ,sad4 ,by this time1 however1 he had become a successful author2 ,brand sold largely1 and has continued to be the most popular of ,ibsen's writings4 ,in #ahff1 moreover1 the ,storthing had been persuaded to vote him a poet's pension1 and there was now an end of ,ibsen's long struggle with poverty4 ,in #ahfh he left ,rome1 and settled in ,dresden until #ahgd1 when he returned to ,norway4 ,but after a short visit he went back to ,germany1 and lived first at ,dresden1 afterwards at ,munich1 and did not finally settle in ,christiania until #ahia4 ,his shorter lyrical poems were collected in #ahga1 and in that year his name and certain of his writings were for the first time mentioned to the ,english public4 ,at this time he was revising his old works1 which were out of print1 and which he would not resign again to the reading world until he had subjected them to what in some instances 7for example1 ,mistress ,inger at straat7 amounted to practical recomposition4 ,in #ahgc he published a double drama1 each part of which was of unusual bulk1 the whole forming the tragedy of ,emperor and ,galilean2 this1 ,ibsen's latest historical play1 has for subject the unsuccessful struggle of ,julian the ,apostate to hold the world against the rising tide of ,christianity4 ,the work is of an experimental kind1 and takes its place between the early poetry and the later prose of the author4 ,compared with the series of plays which ,ibsen had already inaugurated with ,the ,young ,men's ,league1 ,emperor and ,galilean preserves a colour of idealism and even of mysticism which was for many years to be absent from ,ibsen's writings1 but to reappear in his old age with ,the ,master-builder4 ,there is some foundation for the charge that ,ibsen has made his romantic ,greek emperor needlessly squalid1 and that he has robbed him1 at last1 too roughly of all that made him a sympathetic exponent of ,hellenism4 ,ibsen was now greatly occupied by the political spectacle of ,germany at war first in ,denmark1 then in ,france1 and he believed that all things were conspiring to start a new epoch of individualism4 ,he was therefore deeply disgusted by the ,paris commune1 and disappointed by the conservative reaction which succeeded it4 ,this disillusion in political matters had a very direct influence upon ,ibsen's literary work4 ,it persuaded him that nothing could be expected in the way of reform from democracies1 from large blind masses of men moved capriciously in any direction1 but that the sole hope for the future must lie in the study of personality1 in the development of individual character4 ,he set himself to diagnose the conditions of society1 which he had convinced himself lay sick unto death4 ,hitherto ,ibsen had usually employed rhymed verse for his dramatic compositions1 or1 in the case of his saga-plays1 a studied and artificial prose4 ,now1 in spite of the surprising achievements of his poetry1 he determined to abandon versification1 and to write only in the language of everyday conversation4 ,in the first drama of this his new period1 ,the ,pillars of ,society 7#ahgg71 he dealt with the problem of hypocrisy in a small commercial centre of industry1 and he drew in the ,bernick family a marvellous picture of social egotism in a prosperous seaport town4 ,there was a certain similarity between this piece and ,a ,doll's ,house 7#ahgi71 although the latter was much the more successful in awakening curiosity4 ,indeed1 no production of ,ibsen's has been so widely discussed as this1 which is nevertheless not the most coherently conceived of his plays4 ,here also1 social hypocrisy1 was the object of the playwright's satire1 but this time mainly in relation to marriage4 ,in ,a ,doll's ,house ,ibsen first developed his views with regard to the individualism of woman4 ,in his previous writings he had depicted woman as a devoted and willing sacrifice to man2 here he begins to explain that she has no less a duty to herself1 and must keep alive her own conception of honour and of responsibility4 ,the conclusion of ,a ,doll's ,house was violently and continuously discussed through the length and breadth of ,europe1 and to the situation of ,nora ,helmer is probably due more than to anything else the long tradition that ,ibsen is immoral4 ,he braved convention still more audaciously in ,ghosts 7#ahha71 perhaps the most powerful of the series of plays in which ,ibsen diagnoses the diseases of modern society4 ,it was received in ,norway with a tumult of ill-will1 and the author was attacked no less venomously than he had been twenty years before4 ,ibsen was astonished and indignant at the reception given to ,ghosts1 and at the insolent indifferentism of the majority to all ideas of social reform4 ,he wrote1 more as a pamphlet than as a play1 what is yet one of the most effective of his comedies1 ,an ,enemy of the ,people 7#ahhb74 ,dr ,stockmann1 the hero of that piece1 discovers that the drainage system of the bathing-station on which the little town depends is faulty1 and the water impure and dangerous4 ,he supposes that the corporation will be grateful to have these deficiencies pointed out2 on the contrary1 they hound him out of their midst as an enemy of the people4 ,in this play occurs ,ibsen's famous and typical saying1 a minority may be right--a majority is always wrong4 ,this polemical comedy seemed at first to be somewhat weakened by the personal indignation which runs through it1 but it has held the stage4 ,ibsen's next drama1 ,the ,wild ,duck 7#ahhd71 was written in singular contrast with the zest and fire which had inspired ,an ,enemy of the ,people4 ,here he is squalid and pessimistic to a degree elsewhere unparalleled in his writings2 it is not quite certain that he is not here guilty of a touch of parody of himself4 ,the main figure of the play is an unhealthy1 unlucky enthusiast1 who goes about making hopeless mischief by exposing weak places in the sordid subterfuges of others4 ,this drama contains a figure1 ,hjlmar ,ekdal1 who claims the bad pre-eminence of being the meanest scoundrel in all drama4 ,the ,wild ,duck is the darkest1 the least relieved1 of ,ibsen's studies of social life1 and his object in composing it is not obvious4 ,with ,rosmersholm 7#ahhf7 he rose to the height of his genius again2 this is a mournful1 but neither a pessimistic nor a cynical play4 ,the fates which hang round the contrasted lives of ,rosmer and ,rebecca1 the weak-willed scrupulous man and the strong-willed unshrinking woman1 the old culture and the new1 the sickly conscience and the robust one1 create a splendid dramatic antithesis4 ,ibsen then began to compose a series of dramas1 of a more and more symbolical and poetic character2 the earliest of these was the mystical ,the ,lady from the ,sea 7#ahhh74 ,at ,christmas #ahij he brought out ,hedda ,gabler2 two years later ,the ,master-builder 7,bygmester ,solnaes71 in which many critics see the highest attainment of his genius2 at the close of #ahid ,little ,eyolf2 in #ahif ,john ,gabriel ,borkman2 and in #aijj ,when ,we ,dead ,awaken4 ,on the occasion of his seventieth birthday 7#ahih7 ,ibsen was the recipient of the highest honours from his own country and of congratulations and gifts from all parts of the world4 ,a colossal bronze statue of him was erected outside the new ,national ,theatre1 ,christiania1 in ,september #ahii4 ,in #aija his health began to decline1 and he was ordered by the physician to abandon every species of mental effort4 ,the evil advanced1 and he became unconscious of the passage of events4 ,after lingering in this sad condition he died1 without suffering1 on the #bcrd of ,may #aijf1 and was accorded a public funeral1 with the highest national honours4 ,no recent writer belonging to the smaller countries of ,europe has had so widely spread a fame as that of ,ibsen1 and although the value of his dramatic work is still contested1 it has received the compliment of vivacious discussion in every part of the world4 ,there would1 perhaps1 have been less violence in this discussion if it had been perceived that the author does not pose as a moral teacher1 but as an imaginative investigator4 ,he often and with much heat insisted that he was not called upon as a poet to suggest a remedy for the diseases of society1 but to diagnose them4 ,in this he was diametrically opposed to ,tolstoi1 who admitted that he wrote his books for the healing of the nations4 ,if the subjects which ,ibsen treats1 or some of them1 are open to controversy1 we are at least on firm ground in doing homage to the splendour of his art as a playwright4 ,he reintroduced into modern dramatic literature something of the velocity and inevitability of ,greek tragic intrigue4 ,it is very rarely that any technical fault can be found with the architecture of his plots1 and his dialogue is the most lifelike that the modern stage has seen4 ,his long apprenticeship to the theatre was of immense service to him in this respect4 ,in every country1 though least perhaps in ,england1 the influence of ,ibsen has been marked in the theatrical productions of the younger school4 ,even in ,england1 on the rare occasions when his dramas are acted1 they awaken great interest among intelligent playgoers4 ,the editions of ,ibsen's works are numerous1 but the final text is included in the ,samlede ,vaerker1 with a bibliography by ,j4 ,b4 ,halvorsen1 published in ,copenhagen1 in #aj vols4 7#ahih-aijb74 ,they have been translated into the principal ,european languages1 and into ,japanese4 ,the study of ,ibsen in ,english was begun by ,mr ,gosse in #ahgb1 and continued by ,mr ,william ,archer1 whose version of ,ibsen's prose dramas appeared in #e vols4 7#ahij1 #ahia2 new and revised edition1 #aijf74 ,other translators have been ,mr ,c4 ,herford1 ,mr ,r4 ,a4 ,streatfield1 ,miss ,frances ,lord and ,mr ,adie4 ,his ,correspondence was edited1 in #b vols41 under the supervision of his son1 ,sigurd ,ibsen1 in #aijd 7,eng4 trans41 #aije74 ,critical studies on the writings and position of ,ibsen are innumerable1 and only those which were influential in guiding opinion1 during the early part of his career1 in the various countries1 can be mentioned here3 ,georg ,brandes sthetiske ,studier 7,copenhagen1 #ahfh72 ,les ,quesnel1 ,posie scandinave 7,paris #ahgd72 ,valfrid ,valsenius1 ,henrik ,ibsen 7,helsingfors1 #ahgi72 ,edmund ,gosse1 ,studies in ,northern ,literature 7,london1 #ahgi72 ,l4 ,passarge1 ,henrik ,ibsen 7,leipzig1 #ahhc72 ,g4 ,brandes1 ,bjrnson och ,ibsen 7,stockholm1 #ahhb72 ,henrik ,jaeger1 ,henrik ,ibsen #ahbh-ahhh 7,copenhagen1 #ahhh2 ,eng4 trans41 #ahij72 ,t4 ,terwey1 ,henrik ,ibsen 7,amsterdam1 #ahhb72 ,g4 ,bernard ,shaw1 ,the ,quintessence of ,ibsen 7,london1 #ahib74 ,in ,france ,count ,moritz ,prozor carried on an ardent propaganda in favour of ,ibsen from #ahhe1 and ,jules ,lematre's articles in his ,les ,contemporains and ,impressions de thtre did much to encourage discussion4 ,w4 ,archer forwarded the cause in ,england from #ahgh onwards4 ,in ,germany ,ibsen began to be known in #ahff1 when ,john ,grieg1 ,p4 ,f4 ,siebold and ,adolf ,strodtmann successively drew attention to his early dramas2 but his real popularity among the ,germans dates from #ahhj4 7,e4 ,g47 ,,ibycus1 of ,rhegium in ,italy1 ,greek lyric poet1 contemporary of ,anacreon1 flourished in the #fth century ,b4,c4 ,notwithstanding his good position at home1 he lived a wandering life1 and spent a considerable time at the court of ,polycrates1 tyrant of ,samos4 ,the story of his death is thus related3 ,while in the neighbourhood of ,corinth1 the poet was mortally wounded by robbers4 ,as he lay dying he saw a flock of cranes flying overhead1 and called upon them to avenge his death4 ,the murderers betook themselves to ,corinth1 and soon after1 while sitting in the theatre1 saw the cranes hovering above4 ,one of them1 either in alarm or jest1 ejaculated1 ,behold the avengers of ,ibycus1 and thus gave the clue to the detection of the crime 7,plutarch1 ,de ,garrulitate1 xiv474 ,the phrase1 the cranes of ,ibycus1 passed into a proverb among the ,greeks for the discovery of crime through divine intervention4 ,according to ,suidas1 ,ibycus wrote seven books of lyrics1 to some extent mythical and heroic1 but mainly erotic 7,cicero1 ,tusc4 ,disp4 iv4 #cc71 celebrating the charms of beautiful youths and girls4 ,f4 ,g4 ,welcker suggests that they were sung by choruses of boys at the beauty competitions held at ,lesbos4 ,although the metre and dialect are ,dorian1 the poems breathe the spirit of ,aeolian melic poetry4 ,the best editions of the fragments are by ,f4 ,w4 ,schneidewin 7#ahcc7 and ,bergk1 ,potae lyrici ,graeci4 ,,ica 7,,yca1 or ,,ecca71 a city of southern ,peru and the capital of a department of the same name1 #agj m4 ,s4,s4,e4 of ,lima1 and #df m4 by rail ,s4,e4 of ,pisco2 its port on the ,pacific coast4 ,pop4 7#aijf1 official estimate7 #fjjj4 ,it lies in a valley of the foothills of the ,cordillera ,occidental1 which is watered by the ,rio de ,ica1 is made highly fertile by irrigation1 and is filled with vineyards and cotton fields2 between this valley and the coast is a desert4 ,the original town was founded in #aefc1 #d m4 ,e4 of its present site1 but it was destroyed by the earthquake of #aega1 and again by that of #affd1 after which the present town was laid out near the ruins4 ,in #ahhb a ,chilean marauding expedition inflicted great damage to private property in the town and vicinity4 ,these repeated disasters give the place a partially ruined appearance1 but it has considerable commercial and industrial prosperity4 ,it has a large cotton factory and there are some smaller industries4 ,wine-making is one of the principal industries of the valley1 and much brandy1 called pisco1 is exported from ,pisco4 ,a new industry is that of drying the fruits for which this region is celebrated4 ,ica is the seat of a national college4 ,the department of ,,ica lies between the ,western ,cordillera and the ,pacific coast1 and extends from the department of ,lima ,s4,e4 to that of ,arequipa4 ,pop4 7#aijf1 official estimate7 #fh1bbj2 area #hgba sq4 m4 ,ica is in the rainless region of ,peru1 and the greater part of its surface is barren4 ,it is crossed by the rivers ,pisco1 ,ica and ,grande1 whose tributaries drain the western slope of the ,cordillera1 and whose valleys are fertile and highly cultivated4 ,the valley of the ,nasca1 a tributary of the ,grande1 is celebrated for an extensive irrigating system constructed by the natives before the discovery of ,america4 ,the principal products of the department are cotton1 grapes1 wine1 spirits1 sugar and fruit4 ,these are two good ports on the northern coast1 ,tambo de ,mora and ,pisco1 the latter being connected with the capital by a railway across the desert1 #df m4 long4 ,,ice 7a word common to ,teutonic languages2 cf4 ,ger4 ,eis71 the solid crystalline form which water assumes when exposed to a sufficiently low temperature4 ,it is a colourless crystalline substance1 assuming forms belonging to the hexagonal system1 and distinguished by a well-marked habit of twinning1 which occasions the beautiful ice flowers displayed by hoar-frost4 ,it is frequently precipitated as hoar-frost1 snow or hail2 and in the glaciers and snows of lofty mountain systems or of regions of high latitude it exists on a gigantic scale1 being especially characteristic of the seas and lands around the poles4 ,in various regions1 especially in ,france and ,italy1 great quantities of ice form in caves1 which1 in virtue of their depth below the earth's surface1 their height above the sea-level1 or their exposure to suitable winds1 or to two or more of these conditions in combination1 are unaffected by ordinary climatic changes1 so that the mean annual temperature is sufficiently low to ensure the permanency of the ice4 ,the temperature at which water freezes1 and also at which ice melts1 is so readily determined that it is employed as one of the standard temperatures in the graduation of ordinary thermometer scales1 this temperature being the zero of the ,centigrade and ,raumur scales1 and #cb of the ,fahrenheit 7see ,,thermometry74 ,in the act of freezing1 water1 though its temperature remains unchanged1 undergoes a remarkable expansion so that ice at #j ,c4 is less dense than water--a fact demonstrated by its power of floating4 ,the sub-aqueous retention of ground-ice or anchor-ice1 which forms in certain circumstances at the bottom of streams or pools in which there are many eddies1 is due to the cohesion between it and the stones or rocks which compose the bed of the streams or pools4 ,as water expands on freezing1 so conversely ice contracts on melting2 and the ice-cold water thus formed continues to contract when heated until it has reached its point of maximum density1 the temperature at which this occurs being about #ci ,fahr1 or #d ,c4 ,above this point water continuously expands1 and at no temperature is it less dense than ice as is shown by the following table3-- ,density of ice at #j;,c4 4#iage water at #j;,c4 4#iiihh #d;,c4 #a4jjjjj #aj;,c4 4#iiigf #ajj;,c4 4#iehff ,under the influence of heat1 ice itself behaves as most solids do1 contracting when cooled1 expanding when heated4 ,according to ,plcker1 the coefficient of cubical dilatation at moderately low temperatures is #j4jjjaehe4 ,from a series of elaborate experiments1 ,person deduced #j4eje as the specific heat of ice1 or about half that of water4 ,though no rise of temperature accompanies the melting of ice1 there is yet a definite quantity of heat absorbed1 namely1 about #hj calories per gram2 this is called the latent heat of fusion of water 7see ,,fusion74 ,the same amount of heat is evolved when water becomes ice4 ,that ice can be melted by increase of pressure was first pointed out by ,james ,thomson in #ahdi4 ,he showed that1 since water expands on freezing1 the laws of thermodynamics require that its freezing-point must be lowered by increase of pressure2 and he calculated that for every additional atmosphere of pressure the freezing-point of water was lowered by #j4jjge4 ,this result was verified by his brother1 ,sir ,william ,thomson 7,lord ,kelvin71 in #ahej4 ,the ,thomsons and ,h4 ,l4 ,f4 ,helmholtz successfully applied this behaviour of ice under pressure to the explanation of many properties of the substance4 ,when two blocks of ice at #j ,c4 are pressed together or even simply laid in contact1 they gradually unite along their touching surfaces till they form one block4 ,this regelation is due to the increased pressure at the various points of contact causing the ice there to melt and cool4 ,the water so formed tends to escape1 thus relieving the pressure for an instant1 refreezing and returning to the original temperature4 ,this succession of melting and freezing1 with their accompanying thermal effects1 goes on until the two blocks are cemented into one4 ,ice forms over fresh water if the temperature of the air has been for a sufficient time at or below the freezing-point2 but not until the whole mass of water has been cooled down to its point of maximum density1 so that the subsequent cooling of the surface can give rise to no convection currents1 is freezing possible4 ,sea-water1 in the most favourable circumstances1 does not freeze till its temperature is reduced to about -#b ,c42 and the ice1 when formed1 is found to have rejected four-fifths of the salt which was originally present4 ,in the upper provinces of ,india water is made to freeze during cold clear nights by leaving it overnight in porous vessels1 or in bottles which are enwrapped in moistened cloth4 ,the water then freezes in virtue of the cold produced by its own evaporation or by the drying of the moistened wrapper4 ,in ,bengal the natives resort to a still more elaborate forcing of the conditions4 ,pits are dug about #b ft4 deep and filled three-quarters full with dry straw1 on which are set flat porous pans containing the water to be frozen4 ,exposed overnight to a cool dry gentle wind from the north-west1 the water evaporates at the expense of its own heat1 and the consequent cooling takes place with sufficient rapidity to overbalance the slow influx of heat from above through the cooled dense air or from below through the badly conducting straw4 ,see ,,water1 and for the manufacture of ice see ,,refrigerating4 ,,iceberg 7from ice and ,berg1 ,ger4 for hill1 mountain71 a floating mass of ice broken from the end of a glacier or from an ice-sheet4 ,the word is sometimes1 but rarely1 applied to the arch of an ,arctic glacier viewed from the sea4 ,it is more commonly used to describe huge floating masses of ice that drift from polar regions into navigable waters4 ,they are occasionally encountered far beyond the polar regions1 rising into beautiful forms with breakers roaring into their caves and streams of water pouring from their pinnacles in the warmer air4 ,when1 however1 they rest in comparatively warm water1 melting takes place most rapidly at the base and they frequently overturn4 ,only one-ninth of the mass of ice is seen above water4 ,when a glacier descends to the sea1 as in ,alaska1 and advances into water1 the depth of which approaches its thickness1 the ends are broken off and the detached masses float away as icebergs4 ,many of the bergs are overturned1 or at least tilted1 as they set sail4 ,if this does not happen at once it is likely to occur later as the result of the wave-cutting and melting which disturb their equilibrium 7,t4 ,c4 ,chamberlin and ,r4 ,d4 ,salisbury1 ,geology3 ,processes and their ,results1 #aije74 ,these bergs carry a load of dbris from the glacier and gradually strew their load upon the sea floor4 ,they do not travel far before losing all stony and earthy dbris1 but glacial material found in dredgings shows that icebergs occasionally carry their load far from land4 ,the structure of the iceberg varies with its origin and is always that of the glacier or ice-sheet from which it was broken4 ,the breaking off of the ice-sheet from a ,greenland glacier is called locally the calving of the glacier4 ,the constantly renewed material from which the icebergs are formed is brought down by the motion of the glacier4 ,the ice-sheet cracks at the end1 and masses break off1 owing to the upward pressure of the water upon the lighter ice which is pushed into it4 ,this is accomplished with considerable violence4 ,the disintegration of an ,arctic ice-sheet is a simpler matter1 as the ice is already floating4 ,,iceland 7,dan4 ,island71 an island in the ,north ,atlantic ,ocean1 belonging to ,denmark4 ,its extreme northerly point is touched by the ,arctic ,circle2 it lies between #ac #bb and #bd #ce ,w41 and between #fc #ab and #ff #cc ,n41 and has an area of #dj1dcg sq4 m4 ,its length is #bih m4 and its breadth #aid m41 the shape being a rough oval1 broken at the north-west1 where a peninsula1 diversified by a great number of fjords1 projects from the main portion of the island4 ,the total length of the coast-line is about #cgcj m41 of which approximately one-third belongs to the north-western peninsula4 ,iceland is a plateau or tableland1 built up of volcanic rocks of older and younger formation1 and pierced on all sides by fjords and valleys4 ,compared with the tableland1 the lowlands have a relatively small area1 namely1 one-fourteenth of the whole2 but these lowlands are almost the only parts of the island which are inhabited4 ,in consequence of the rigour of its climate1 the central tableland is absolutely uninhabitable4 ,at the outside1 not more than one-fourth of the area of ,iceland is inhabited2 the rest consists of elevated deserts1 lava streams and glaciers4 ,the north-west peninsula is separated from the main mass of the island by the bays ,hunafli and ,breiifjrr1 so that there are really two tablelands1 a larger and a smaller4 ,the isthmus which connects the two is only #d m4 across1 but has an altitude of #gdh ft4 ,the mean elevation of the north-west peninsula is #bjjj ft4 ,the fjords and glens which cut into it are shut in by precipitous walls of basalt1 which plainly shows that they have been formed by erosion through the mass of the plateau4 ,the surface of this tableland is also bare and desolate1 being covered with gravel and fragments of rock4 ,here and there are large straggling snowfields1 the largest being ,glmu and ,drangajkull1#a on the culminating points of the plateau4 ,the only inhabited districts are the shores of the fjords1 where grass grows capable of supporting sheep2 but a large proportion of the population gain their livelihood by fishing4 ,the other and larger tableland1 which constitutes the substantial part of ,iceland1 reaches its culminating point in the south-east1 in the gigantic snowfield of ,vatnajkull1 which covers #ccjj sq4 m4 ,the axis of highest elevation of ,iceland stretches from north-west to south-east1 from the head of ,hvammsfjrr to ,hornafjrr1 and from this water-parting the rivers descend on both sides4 ,the crest of the water-parting is crowned by a chain of snow-capped mountains1 separated by broad patches of lower ground4 ,they are really a chain of minor plateaus which rise #dejj to #fbej ft4 above sea-level and #bjjj to #cjjj ft4 above the tableland itself4 ,in the extreme east is ,vatnajkull1 which is separated from ,tungnafellsjkull by ,vonarskard 7#ccjj ft474 ,between ,tungnafellsjkull and ,hofsjkull lies the broad depression of ,sprengisandr 7#bacj ft474 ,continuing north-west1 between ,hofsjkull and the next snow-capped mountain1 ,langjkull1 lies ,kjlur 7#bjjj ft472 and between ,langjkull and ,eiriksjkull1 ,flosaskard 7#bfcj ft474 ,to the north of the jklar last mentioned there are a number of lakes1 all well stocked with fish4 ,numerous valleys or glens penetrate into the tableland1 especially on the north and east1 and between them long mountain spurs1 sections of the tableland which have resisted the action of erosion1 thrust themselves towards the sea4 ,of these the most considerable is the mass crowned by ,mrdalsjkull1 which stretches towards the south4 ,the interior of the tableland consists for the most part of barren1 grassless deserts1 the surface being covered by gravel1 loose fragments of rock1 lava1 driftsand1 volcanic ashes and glacial detritus4 ,save the lower parts of the larger glens1 there are no lowlands on the north and east4 ,the south coast is flat next the sea2 but immediately underneath ,vatnajkull there is a strip of gravel and sand1 brought down and deposited by the glacial streams4 ,the largest low-lying plain of ,iceland1 lying between ,mrdalsjkull and ,reykjanes1 has an area of about #aeej sq4 m4 ,in its lowest parts this plain barely keeps above sea-level1 but it rises gradually towards the interior1 terminating in a ramification of valleys4 ,its maximum altitude is attained at #cha ft4 near ,geysir4 ,on the west of ,mount ,hekla this plain connects by a regular slope directly with the tableland1 to the great injury of its inhabited districts1 which are thus exposed to the clouds of pumice dust and driftsand that cover large areas of the interior4 ,nevertheless the greater part of this lowland plain produces good grass1 and is relatively well inhabited4 ,the plain is drained by three rivers--,markarfljt1 ,thjrs and ,oelfus--all of large volume1 and numerous smaller streams4 ,towards the west there exist a number of warm springs4 ,there is another lowland plain around the head of ,faxafli1 nearly #djj sq4 m4 in extent4 ,as a rule the surface of this second plain is very marshy4 ,several dales or glens penetrate the central tableland2 the eastern part of this lowland is called ,borgarfjrr1 the western part ,mrar4 ,the great bays on the west of the island 7,faxafli and ,breiifjrr71#b as well as the many bays on the north1 which are separated from one another by rocky promontories1 appear to owe their origin to subsidences of the surface2 whereas the fjords of the north-west peninsula1 which make excellent harbours1 and those of the east coast seem to be the result chiefly of erosion4 ,illustration3 ,map of ,iceland4 ,glaciers4--,an area of #eagj sq4 m4 is covered with snowfields and glaciers4 ,this extraordinary development of ice and snow is due to the raw1 moist climate1 the large rainfall and the low summer temperature4 ,the snow-line varies greatly in different parts of the island1 its range being from #acjj to #dbej ft4 ,it is highest on the tableland1 on the north side of ,vatnajkull1 and lowest on the north-west peninsula1 to the south of ,north ,cape4 ,without exception the great nvs of ,iceland belong to the interior tableland4 ,they consist of slightly rounded domes or billowy snowfields of vast thickness4 ,in external appearance they bear a closer resemblance to the glaciers of the ,polar regions than to those of the ,alps4 ,the largest snowfields are ,vatnajkull 7#cbhj sq4 m471 ,hofsjkull 7#ebj7 ,langjkull 7#ejj7 and ,mrdalsjkull 7#cij74 ,the glaciers which stream off from these snowfields are often of vast extent1 e4g4 the largest glacier of ,vatnajkull has an area of #aej to #bjj sq4 m41 but the greater number are small4 ,altogether1 more than #abj glaciers are known in ,iceland4 ,it is on the south side of ,vatnajkull that they descend lowest2 the lower end of ,breidamerkurjkull was in the year #ahid only #cj ft4 above sea-level4 ,the glaciers of the north-west peninsula also descend nearly to sea-level4 ,the great number of streams of large volume is due to the moist climate and the abundance of glaciers1 and the milky white or yellowish-brown colour of their waters 7whence the common name ,hvt1 white7 is due to the glacial clays4 ,the majority of them change their courses very often1 and vary greatly in volume2 frequently they are impetuous torrents1 forming numerous waterfalls4 ,iceland also possesses a great number of lakes1 the largest being ,thingvallavatn#c and ,thorisvatn1 each about #bg sq4 m4 in area4 ,mvatn1 in the north1 is well known from the natural beauty of its surroundings4 ,above its surface tower a great number of volcanoes and several craters1 and its waters are alive with water-fowl1 a multitude of ducks of various species breeding on its islands4 ,the lakes of ,iceland owe their origin to different causes1 some being due to glacial erosion1 others to volcanic subsidence4 ,mvatn fills a depression between lava streams1 and has a depth of not more than #h ft4 ,the group of lakes called ,fiskivtn 7or ,veidivtn71 which lie in a desolate region to the west of ,vatnajkull1 consist for the most part of crater lakes4 ,the groups of lakes which lie north-west from ,langjkull occupy basins formed between ridges of glacial gravel2 and in the valleys numerous lakes are found at the backs of the old moraines4 ,volcanoes4--,iceland is one of the most volcanic regions of the earth2 volcanic activity has gone on continuously from the formation of the island in the ,tertiary period down to the present time4 ,so far as is known1 there have in historic times been eruptions from twenty-five volcanic vents4 ,altogether #ajg volcanoes are known to exist in ,iceland1 with thousands of craters1 great and small4 ,the lava-streams which have flowed from them since the ,glacial epoch now cover an area of #dfej sq4 m4 ,they are grouped in dense masses round the volcanoes from which they have flowed1 the bulk of the lava dating from outbreaks which occurred in prehistoric times4 ,the largest volume of lava which has issued at one outflow within historic times is the stream which came from the craters of ,laki at ,skapt4 ,this belongs to the year #aghc1 and covers an area of #bah sq4 m41 and amounts to a volume represented by a cube each of whose sides measures #g m4 ,the largest unbroken lava-field in ,iceland is ,odaahraun 7,lava of ,evil ,deeds71 upon the tableland north from ,vatnajkull 7#bjjj to #djjj ft4 above sea-level74 ,it is the accretion of countless eruptions from over twenty volcanoes1 and covers an area of #acjj sq4m4 7or1 including all its ramifications and minor detached streams1 #agjj sq4 m471 and its volume would fill a cube measuring #ac4d m4 in every direction4 ,as regards their superficies1 the lava-streams differ greatly4 ,sometimes they are very uneven and jagged 7apalhraun71 consisting of blocks of lava loosely flung together in the utmost confusion4 ,the great lava-fields1 however1 are composed of vast sheets of lava1 ruptured and riven in divers ways 7helluhraun74 ,the smooth surface of the viscous billowy lava is further diversified by long twisted ropes1 curving backwards and forwards up and down the undulations4 ,moreover1 there are gigantic fissures1 running for several miles1 caused by subsidences of the underlying sections4 ,the best-known fissure of this character is ,almannagj at ,thingvellir4 ,on the occasion of outbreaks the fine ashes are scattered over a large portion of the island1 and sometimes carried far across the ,atlantic4 ,after the eruption of ,katla in #afbe the ashes were blown as far as ,bergen in ,norway1 and when ,askja was in eruption in #ahge a rain of ashes fell on the west coast of ,norway #aa hours #dj minutes1 and at ,stockholm #ae hours1 afterwards4 ,the volcanic ash frequently proves extremely harmful1 destroying the pastures so that the sheep and cattle die of hunger and disease4 ,the outbreak of ,laki in #aghc occasioned the loss of #aa1ejj cattle1 #bh1jjj horses and #aij1ejj sheep--that is to say1 #ec of the cattle in the island1 #gg of the horses and #hb of the sheep4 ,after that the island was visited by a famine1 which destroyed #iejj people1 or one-fifth of the total population4 ,the ,icelandic volcanoes may be divided into three classes3 7#a7 cone-shaped1 like ,vesuvius1 built up of alternate layers of ashes1 scoriae and lava2 7#b7 cupola-shaped1 with an easy slope and a vast crater opening at the top--these shield-shaped cupolas are composed entirely of layers of lava1 and their inclination is seldom steeper than #g-h2 7#c7 chains of craters running close alongside a fissure in the ground4 ,for the most part the individual craters are low1 generally not exceeding #cjj to #ejj ft4 ,these crater chains are both very common and often very long4 ,the chain of ,laki1 which was formed in #aghc1 extends #bj m41 and embraces about one hundred separate craters4 ,sometimes1 however1 the lava-streams are vomited straight out of gigantic fissures in the earth without any crater being formed4 ,many of the ,icelandic volcanoes during their periods of quiescence are covered with snow and ice4 ,then when an outbreak occurs the snow and ice melt1 and in that way they sometimes give rise to serious catastrophes 7jkulhlaup71 through large areas being suddenly inundated by great floods of water1 which bear masses of ice floating on their surface4 ,katla caused very serious destruction in this way by converting several cultivated districts into barren wastes4 ,in the same way in the year #acfb ,oerfajkull1 the loftiest mountain in ,iceland 7#fdbd ft471 swept forty farms1 together with their inhabitants and live stock1 bodily into the ocean4 ,the best-known volcano is ,hekla 7#eajh ft471 which was in eruption eighteen times within the historic period down to #ahde4 ,katla during the same period was active thirteen times down to #ahfj4 ,the largest volcano is ,askja1 situated in the middle of the lava-field of ,odaahraun4 ,its crater measures #cd sq4 m4 in area4 ,at ,mvatn there are several volcanoes1 which were particularly active in the years #agbd-agcj4 ,on several occasions there have been volcanic outbreaks under the sea outside the peninsula of ,reykjanes1 islands appearing and afterwards disappearing again4 ,the crater chain of ,laki has only been in eruption once in historic times1 namely1 the violent and disastrous outbreak of #aghc4 ,iceland1 however1 possesses no constantly active volcano4 ,there are often long intervals between the successive outbreaks1 and many of the volcanoes 7and this is especially true of the chains of craters7 have only vented themselves in a solitary outburst4 ,earthquakes are frequent1 especially in the districts which are peculiarly volcanic4 ,historical evidence goes to show that they are closely associated with three naturally defined regions3 7#a7 the region between ,skjlfandi and ,axarfjrr in the north1 where violent earth tremblings are extremely common2 7#b7 at ,faxafli1 where minor vibrations are frequent2 7#c7 the southern lowlands1 between ,reykjanes and ,mrdalsjkull1 have frequently been devastated by violent earthquake shocks1 with great loss of property and life1 e4g4 on the #adth-#afth of ,august #aghd1 when #ib farmsteads were totally destroyed1 and #cgb farmsteads and #aa churches were seriously damaged2 and again in ,august and ,september #ahif1 when another terrible earthquake destroyed #afa farmsteads and damaged #aee others4 ,hot springs are found in every part of ,iceland1 both singly and in groups2 they are particularly numerous in the western portion of the southern lowlands1 where amongst others is the famous ,geyser 7q4v474 ,sulphur springs and boiling mud lakes are also general in the volcanic districts2 and in places there are carbonic acid springs1 these more especially on the peninsula of ,snfellsnes1 north of ,faxafli4 ,geology4--,iceland is built up almost entirely of volcanic rocks1 none of them older1 however1 than the middle of the ,tertiary period4 ,the earlier flows were probably contemporaneous with those of ,greenland1 the ,froes1 the western islands of ,scotland and the north-east of ,ireland4 ,the principal varieties are basalt and palagonitic breccias1 the former covering two-thirds of the entire area1 the latter the remaining one-third4 ,compared with these two systems1 all other formations have an insignificant development4 ,the palagonitic breccias1 which stretch in an irregular belt across the island1 are younger than the basalt4 ,in the north-west1 north and east the coasts are formed of basalt1 and rise in steep1 gloomy walls of rock to altitudes of #cjjj ft4 and more above sea-level4 ,deposits of clay1 with remains of plants of the ,tertiary period1 lignite and tree-trunks pressed flat1 which the ,icelanders call surtarbrandur1 occur in places in the heart of the basalt formation4 ,these fossiliferous strata are developed in greatest thickness in the north-west peninsula4 ,indeed1 in some few places well-marked impressions of leaves and fruit have been discovered1 proving that in ,tertiary times ,iceland possessed extensive forests1 and its annual mean temperature must have been at least #dh ,fahr41 whereas the present mean is #ce4f4 ,the palagonitic breccias1 which attain their greatest development in the south of the island and on the tableland1 consist of reddish1 brown or yellowish rocks1 tuffs and breccias1 belonging to several different groups or divisions1 the youngest of which seems to be of a date subsequent to the ,glacial epoch4 ,all over ,iceland1 in both the basalt and breccia formations1 there occur small intrusive beds and dikes of liparite1 and as this rock is of a lighter colour than the basalt1 it is visible from a distance4 ,in the south-east of the island1 in the parish of ,ln1 there exist a few mountains of gabbro1 a rock which does not occur in any other part of ,iceland4 ,near ,hsavik in the north there have been found marine deposits containing a number of marine shells2 they belong to the ,red ,crag division of the ,pliocene4 ,in the middle of ,iceland1 where the geological foundation is tuff and breccias1 large areas are buried under ancient outflows of lava1 which bear evidences of glacial scratching4 ,these lava streams1 which are of a doleritic character1 flowed before the ,glacial age1 or during its continuance1 out of lava cones with gigantic crater openings1 such as may be seen at the present day4 ,during the ,glacial epoch the whole of ,iceland was covered by a vast sheet of inland ice1 except for a few small isolated peaks rising along its outer margins4 ,this ice-cap had on the tableland a thickness of #bcjj to #bfjj ft4 ,rocks scored by glacial ice and showing plain indications of striation1 together with thousands of erratic blocks1 are found scattered all over ,iceland4 ,signs of elevation subsequent to the ,glacial epoch are common all round the island1 especially on the north-west peninsula4 ,there are found strikingly developed marine terraces of gravel1 shore lines and surf beaches marked on the solid rock4 ,in several places there are traces of shells2 and sometimes skeletal remains of whales and walruses1 as well as ancient driftwood1 have been discovered at tolerable distances from the present coast4 ,the ancient shore-lines occur at two different altitudes4 ,along the higher1 #bcj to #bff ft4 above the existing sea-level1 shells have been found which are characteristic of high ,arctic latitudes and no longer exist in ,iceland2 whereas on the lower shore-line1 #ajj to #acj ft41 the shells belong to species which occur amongst the coast fauna of the present day4 ,the geysers and other hot springs are due to the same causes as the active volcanoes1 and the earthquakes are probably manifestations of the same forces4 ,a feature of special interest to geologists in the present conditions of the island is the great power of the wind both as a transporting and denuding agent4 ,the rock sculpture is often very similar to that of a tropical desert4#d ,climate4--,considering its high latitude and situation1 ,iceland has a relatively mild climate4 ,the meteorological conditions vary greatly1 however1 in different parts of the island4 ,in the south and east the weather is generally changeable1 stormy and moist2 whilst on the north the rainfall is less4 ,the climate of the interior tableland approximates to the continental type and is often extremely cold4 ,the mean annual temperature is #cg4b ,f4 in ,stykkishlmr on ,breiifjrr1 #ch4e at ,eyrarbakki in the south of ,iceland1 #da at ,vestmannyjar1 #cf at ,akureyri in the north1 #cf4g on ,berufjrr in the east1 and #cj4f at ,mdrudalr on the central tableland4 ,the range is great not only from year to year1 but also from month to month4 ,for instance1 at ,stykkishlmr the highest annual mean for ,march was #ci4g1 and the lowest #h1 during a period of thirty-eight years4 ,iceland lies contiguous to that part of the north ,atlantic in which the shifting areas of low pressure prevail1 so that storms are frequent and the barometer is seldom firm4 ,the barometric pressure at sea-level in the south-west of ,iceland during the period #ahgh-aijj varied between #cj4h and #bg4a in4 ,the climate of the coasts is relatively mild in summer1 but tolerably cold in winter4 ,the winter means of the north and east coasts average #ca4g and #ca4c ,f4 respectively2 the summer means1 #db4h and #dd4f2 and the means of the year1 #cc4a and #ce4f4 ,the winter means of the south and west coasts average #cb and #ca4g respectively2 the summer means1 #dh4b and #ej2 the annual means1 #cg4d and #ci4b4 ,the rainfall on the south and east coasts is considerable1 e4g4 at ,vestmannyjar1 #di4d in4 in the year2 at ,berufjrr1 #dc4f in4 ,on the west coast it is less1 e4g4 #bd4c in4 at ,stykkishlmr2 but least of all on the north coast1 being only #ad4f in4 on the island of ,grimsey1 which lies off that coast4 ,mist is commonly prevalent on the east coast2 at ,berufjrr there is mist on no fewer than #bab days in the year4 ,the south and west coasts are washed by the ,gulf ,stream1 and the north coast by an ,arctic current1 which frequently brings with it a quantity of drift-ice1 and thus exercises a considerable effect upon the climate of the island2 sometimes it blocks the north coast in the summer months4 ,on the whole1 during the #aith century1 the north coast was free from ice on an average of one year in every four or five4 ,the clearness of the atmosphere has been frequently remarked4 ,thunderstorms occur mostly in winter4 ,flora4--,the vegetation presents the characteristics of an ,arctic ,european type1 and is tolerably uniform throughout the island1 the differences even on the tableland being slight4 ,at present #dce species of phanerogams and vascular cryptogams are known2 the lower orders have been little investigated4 ,the grasses are of the greatest importance to the inhabitants1 for upon them they are dependent for the keep of their live stock4 ,heather covers large tracts1 and also affords pasture for sheep4 ,the development of forest trees is insignificant4 ,birch woods exist in a good many places1 especially in the warmer valleys2 but the trees are very short1 scarcely attaining more than #c to #aj ft4 in height4 ,in a few places1 however1 they reach #ac to #bj ft4 and occasionally more4 ,a few mountain ash or rowan trees 7,sorbus aucuparia7 are found singly here and there1 and attain to #cj ft4 in height4 ,willows are also pretty general1 the highest in growth being ,salix phyllicifolia1 #g to #aj ft4 ,the wild flora of ,iceland is small and delicate1 with bright bloom1 the heaths being especially admired4 ,wild crowberries and bilberries are the only fruit found in the island4 ,fauna4--,the ,icelandic fauna is of a sub-,arctic type4 ,but while the species are few1 the individuals are often numerous4 ,the land mammals are very poorly represented2 and it is doubtful whether any species is indigenous4 ,the polar bear is an occasional visitant1 being brought to the coast by the ,greenland drift-ice4 ,foxes are common1 both the white and the blue occurring2 mice and the brown rat have been introduced1 though one variety of mouse is possibly indigenous4 ,reindeer were introduced in #aggj4 ,the marine mammalia are numerous4 ,the walrus is now seldom seen1 although in prehistoric times it was common4 ,there are numerous species of seals2 and the seas abound in whales4 ,of birds there are over #ajj species1 more than one-half being aquatic4 ,in the interior the whistling swan is common1 and numerous varieties of ducks are found in the lakes4 ,the eider duck1 which breeds on the islands of ,breiifjrr1 is a source of livelihood to the inhabitants1 as are also the many kinds of sea-fowl which breed on the sea-cliffs4 ,iceland possesses neither reptiles nor batrachians4 ,the fish fauna is abundant in individuals1 some sixty-eight species being found off the coasts4 ,the cod fisheries are amongst the most important in the world4 ,large quantities of herring1 plaice and halibut are also taken4 ,many of the rivers abound in salmon1 and trout are plentiful in the lakes and streams4 ,population and ,towns4--,the census of #ahij gave a total population of #gj1ibg1 and this number had increased by #aija to #gh1dhi4 ,the increase during the #aith century was #bg1jjj1 while at least #ae1fjj ,icelanders emigrated to ,america1 chiefly to ,manitoba1 from #ahgb to the close of the century4 ,the largest town is ,reykjavik on ,faxafli1 with #fgjj inhabitants1 the capital of the island1 and the place of residence of the governor-general and the bishop4 ,here the ,althing meets2 and here1 further1 are the principal public institutions of the island 7library1 schools1 c474 ,the town possesses a statue to ,thorvaldsen1 the famous sculptor1 who was of ,icelandic descent4 ,the remaining towns include ,isafjrr 7pop4 #ajjj7 on the north-west peninsula1 ,akureyri 7#ajjj7 on the north and ,seydisfjrr 7#hjj7 in the east4 ,industries4--,the principal occupation of the ,icelanders is cattle-breeding1 and more particularly sheep-breeding1 although the fishing industries have come rapidly to the front in modern times4 ,in #ahej1 #hb of the population were dependent upon cattle-breeding and #g upon fishing2 in #ahij the numbers were #fd and #ah respectively4 ,the culture of grain is not practised in ,iceland2 all bread-stuffs are imported4 ,in ancient times barley was grown in some places1 but it never paid for the cost of cultivation4 ,cattle-breeding has declined in importance1 while the number of sheep has increased4 ,formerly gardening was of no importance1 but considerable progress has been made in this branch in modern times1 as also in the cultivation of potatoes and turnips4 ,fruit-trees will not thrive2 but black and red currants and rhubarb are grown1 the last-named doing excellently4 ,iceland possesses four agricultural schools1 one agricultural society1 and small agricultural associations in nearly every district4 ,the fisheries give employment to about #ab1jjj people4 ,for the most part the fishing is carried on from open boats1 notwithstanding the dangers of so stormy a coast4 ,but larger decked vessels have come into increasing use4 ,in summer the waters are visited by a great number of foreign fishermen1 inclusive of about #cjj fishing-boats from ,french ports1 as well as by fishing-boats from the ,froes and ,norway1 and steam trawlers from ,england4 ,excellent profit is made in certain parts of the island from the herring fishery2 this is especially the case on the east coast4 ,there are marine insurance societies and a school of navigation at ,reykjavik4 ,the export of fish and fish products has greatly increased4 ,in #ahdi to #ahee the annual average exported was #adhj tons2 whereas at the close of the century 7in #ahii7 it amounted to #aa1cci tons and #fh1jgi barrels of oil1 valued at #bgf1eif4 ,commerce4--,from the first colonization of the island down to the #adth century the trade was in the hands of native ,icelanders and ,norsemen2 in the #aeth century it was chiefly in the hands of the ,english1 in the #afth of ,germans from the ,hanse towns4 ,from #afjb to #aghf commerce was a monopoly of the ,danish government2 in the latter year it was declared free to all ,danish subjects and in #ahed free to all nations4 ,since #ahgd1 when ,iceland obtained her own administration1 commerce has increased considerably4 ,thus the total value of the imports and exports together in #ahdi did not exceed #agj1jjj2 while in #ahia-ahie the imports averaged #cef1jjj and the exports #cdj1jjj4 ,in #aijb imports were valued at #eif1aic and exports at #eaa1jhc4 ,trade is almost entirely with ,denmark1 the ,united ,kingdom1 and ,norway and ,sweden1 in this order according to value4 ,the principal native products exported are live sheep1 horses1 salt meat1 wool and hides1 to which must be added the fish products--cod1 train-oil1 herring and salmon--eiderdown and woollen wares4 ,the spinning1 weaving and knitting of wool is a widespread industry1 and the native tweed 7vamal7 is the principal material for the clothing of the inhabitants4 ,the imports consist principally of cereals and flour1 coffee1 sugar1 ale1 wines and spirits1 tobacco1 manufactured wares1 iron and metal wares1 timber1 salt1 coal1 c4 ,the money1 weights and measures in use are the same as in ,denmark4 ,the ,islands ,bank in ,reykjavik 7#aijd7 is authorized to issue bank-notes up to #acc1ijj in total value4 ,communications4--,all land journeys are made on horseback1 and in the remoter parts all goods have to be transported by the same means4 ,throughout the greater part of the island there exist no proper roads even in the inhabited districts1 but only bridle-paths1 and in the uninhabited districts not even these4 ,nevertheless much has been done to improve such paths as there are1 and several miles of driving roads have been made1 more particularly in the south4 ,since #ahhh many bridges have been built2 previous to that year there was none4 ,the larger rivers have been spanned by iron swing-bridges1 and the ,blanda is crossed by a fixed iron bridge4 ,postal connexion is maintained with ,denmark by steamers1 which sail from ,copenhagen and call at ,leith4 ,besides1 steamers go round the island1 touching at nearly every port4 ,religion4--,the ,icelanders are ,lutherans4 ,for ecclesiastical purposes the island is divided into #bj deaneries and #adb parishes1 and the affairs of each ecclesiastical parish are administered by a parish council1 and in each deanery by a district 7hjera7 council4 ,when a living falls vacant1 the governor-general of the island1 after consultation with the bishop1 selects three candidates1 and from these the congregation chooses one1 the election being subsequently confirmed by the governor-general4 ,in the case of certain livings1 however1 the election requires confirmation by the crown4 ,in #ahdg a theological seminary was founded at ,reykjavik1 and there the majority of the ,icelandic ministry are educated2 some1 however1 are graduates of the university of ,copenhagen4 ,health4--,the public health has greatly improved in modern times2 the death-rate of young children has especially diminished4 ,this improvement is due to greater cleanliness1 better dwellings1 better nourishment1 and the increase in the number of doctors4 ,there are now doctors in all parts of the country1 whereas formerly there were hardly any in the island4 ,there is a modern asylum for leprosy at ,laugarnes near ,reykjavik1 and a medical school at ,reykjavik1 opened in #ahgf4 ,the general sanitary affairs of the island are under the control of a chief surgeon 7national physician7 who lives in ,reykjavik1 and has superintendence over the doctors and the medical school4 ,government4--,according to the constitution granted to ,iceland in #ahgd1 the king of ,denmark shares the legislative power with the ,althing1 an assembly of #cf members1 #cj of whom are elected by household suffrage1 and #f nominated by the king4 ,the ,althing meets every second year1 and sits in two divisions1 the upper and the lower4 ,the upper division consists of the #f members nominated by the king and #f elected by the representatives of the people out of their own body4 ,the lower division consists of the remaining #bd representative members4 ,the minister for ,iceland1 who resided in ,copenhagen until #aijc1 when his office was transferred to ,reykjavik1 is responsible to the king and the ,althing for the maintenance of the constitution1 and he submits to the king for confirmation the legislative measures proposed by the ,althing4 ,the king appoints a governor-general 7landshfingi7 who is resident in the island and carries on the government on the responsibility of the minister4 ,formerly ,iceland was divided into four quarters1 the east1 the south1 the west and north4 ,now the north and the east are united under one governor1 and the south and the west under another4 ,the island is further divided into #ah sslur 7counties71 and these again into #afi hreppur 7rapes7 or poor-law districts4 ,responsible to the governors are the sheriffs 7sslumenn71 who act as tax gatherers1 notaries public and judges of first instance2 the sheriff has in every hreppur an assistant1 called hreppstjri4 ,in every hreppur there is also a representative committee1 who administer the poor laws1 and look after the general concerns of the hreppur4 ,these committees are controlled by the committees of the sslur 7county boards71 and these again are under the control of the amtsr 7quarter board71 consisting of three members4 ,from the sheriff courts appeals lie to the superior court at ,reykjavik1 consisting of three judges4 ,appeals may be taken in all criminal cases and most civil cases to the supreme court at ,copenhagen4 ,iceland has her own budget1 the ,althing having1 by the constitution of #ahgd1 the right to vote its own supplies4 ,as the ,althing only meets every other year1 the budget is passed for two years at once4 ,the total income and expenditure are each about #gj1jjj per financial period4 ,there is a national reserve fund of about #fj1jjj1 but no public debt2 nor is there any contribution for either military or naval purposes4 ,iceland has her own customs service1 but the only import duties levied are upon spirits1 tobacco1 coffee and sugar1 and in each case the duties are fairly low4 ,education4--,education is pretty widespread amongst the people4 ,in the towns and fishing villages there are a few elementary schools1 but often the children are instructed at home2 in some places by peripatetic teachers4 ,it is incumbent upon the clergy to see that all children are taught reading1 writing and arithmetic4 ,the people are great readers2 considering the number of the inhabitants1 books and periodicals have a very extensive circulation4 ,eighteen newspapers are issued 7once and twice a week71 besides several journals1 and ,iceland has always been distinguished for her native literature4 ,at ,reykjavik there are a ,latin school1 a medical school and a theological school2 at ,mdruvellir and ,hafnarfjrr1 modern high schools 7,realschulen72 and in addition to these there are four agricultural schools1 a school of navigation1 and three girls' schools4 ,the national library at ,reykjavik contains some #dj1jjj volumes and #cjjj ,,mss4 ,at the same place there is also a valuable archaeological collection4 ,amongst the learned societies are the ,icelandic ,literary ,society 7,bokmentafjelag71 the society of the ,friends of the ,people1 and the ,archaeological ,society of ,reykjavik4 ,,authorities4--,among numerous works of ,dr ,thorvald ,thoroddsen1 see ,geschichte der ,islands ,geographie 7,leipzig1 #ahih72 and the following articles in ,geografisk ,tidskrift 7,copenhagen73 ,om ,islands geografiske og geologiske ,undersgelse 7#ahic72 ,islandske ,fjorde og ,bugter 7#aija72 ,geog4 og geol4 ,unders4 ved den sydlige ,del af ,faxafli paa ,island 7#aijc72 ,lavarkener og ,vulkaner paa ,islands ,hjland 7#aije74 ,see also ,c4 ,s4 ,forbes1 ,iceland 7,london1 #ahfj72 ,s4 ,baring-,gould1 ,iceland1 its ,scenes and ,sagas 7,london1 #ahfc72 ,sir ,r4 ,f4 ,burton1 ,ultima ,thule 7,edinburgh1 #ahge72 ,w4 ,t4 ,mc,cormick1 ,a ,ride across ,iceland 7,london1 #ahib72 ,j4 ,coles1 ,summer ,travelling in ,iceland 7,london1 #ahhb72 ,h4 ,j4 ,johnston ,lavis1 ,notes on the ,geography1 ,geology1 ,agriculture and ,economics of ,iceland1 ,scott4 ,geog4 ,mag4 xi4 7#ahie72 ,w4 ,bisiker1 ,across ,iceland 7,london1 #aijb72 ,j4 ,hann1 ,die ,anomalien der ,witterung auf ,island in dem ,zeitraume #ahea-aijj1 c41 ,sitzungsberichte1 ,vienna ,acad4 ,sci4 7#aijd72 ,p4 ,hermann1 ,island in ,vergangenheit und ,gegenwart 7,leipzig1 #aijg74 ,also ,geografisk ,tidskrift1 and the ,geographical ,journal 7,london71 passim4 7,th4 ,t47 ,,history ,shortly after the discovery of ,iceland by the ,scandinavian1 c4 #hej 7it had long been inhabited by a small colony of ,irish ,culdees71 a stream of immigration set in towards it1 which lasted for sixty years1 and resulted in the establishment of some #djjj homesteads4 ,in this immigration three distinct streams can be traced4 7#a7 ,about #hgj-hij four great noblemen from ,norway1 ,ingolf1 ,ketil ,hng1 ,skalla-,grim and ,thorolf1 settled with their dependants in the south-west of the new found land4 7#b7 ,in #hij-ijj there came from the western ,islands ,queen ,aud1 widow of ,olaf the ,white1 king of ,dublin1 preceded and followed by a number of her kinsmen and relations 7many like herself being ,christians71 ,helgi ,biolan1 ,biorn the ,eastern1 ,helgi the ,lean1 ,ketil the ,foolish1 c41 who settled the best land in the island 7west1 north-west and north71 and founded families who long swayed its destinies4 ,there also came from the ,western ,islands a fellowship of vikings seeking a free home in the north4 ,they had colonized the west in the viking times2 they had fought at ,hafursfirth1 helping their stay-at-home kinsmen against the centralization of the great head-king1 who1 when he had crushed opposition in ,norway1 followed up his victory by compelling them to flee or bow to his rule4 ,such were ,ingimund the ,old1 ,geirmund ,hellskin1 ,thord ,beardie 7who had wed ,st4 ,edmund's granddaughter17 ,audun ,shackle1 ,bryniulf the ,old1 ,uni1 to whom ,harold promised the earldom of the new land if he could make the settlers acknowledge him as king 7a hopeless project71 and others by whom the north-west1 north and east were almost completely claimed4 7#c7 ,in #ijj-icj a few more incomers direct from ,norway completed the settlement of the south1 north-east and south-east4 ,among them were ,earl ,hrollaug 7half-brother of ,hrolf ,ganger and of the first earl of ,orkney71 ,hialti1 ,hrafnkell ,frey's priest1 and the sons of ,asbiorn4 ,fully three-quarters of the land was settled from the west1 and among these immigrants there was no small proportion of ,irish blood4 ,in #aajj there were #dejj franklins1 i4e4 about #ej1jjj souls4 ,table of ,icelandic ,literature and ,history4 ---------------------------------------- ------------------------------------- ,i4 ,the ,commonwealth4 #djj years4 ,heroic ,age4 #hgj- #icj ,poetry of ,western ,islands4 ,settlement by colonists from ,western ,isles and ,norway4 #icj- #ihj ,early ,icelandic poets1 ,constitution worked out--,events of chiefly abroad4 earlier sagas take place4 #ihj-ajcj ,icelandic poets abroad4 ,christianity comes in--,events of ------------ later sagas take place4 ,saga ,telling4 #ajcj-aajj ,first era of phonetic ,peace--,ecclesiastical organization4 change4 ------------ ,the ,literary ,age4 #aajj-aaej ,,ari and his school-- ,,thorodd--,vernacular writing begins4 #aaej-abbj ,,saga-,,writers--,second ,first civil wars--#abjh-bb--,rise of generation of historians4 ,sturlungs4 #abbj-abdh ,,snorri and his ,second civil wars1 #abbf-eh--;,fall school--,biographers4 of ,great ,houses4 #abdh-abhd ,,sturla--,second era of ,change of law1 #abga--,submission to phonetic change4 ,norwegian kings4 ------------ ,,ii4 ,medievalism4 #bej years4 ,continental ,influence chiefly ,norse4 #abhd-acbj ,collecting and editing-- ,foreign influence through ,norway4 ,foreign romances4 #acbj-acij ,annalists--,copyists--,new ,great eruptions1 #acfb and ,medieval poetry begins4 #achi--;,epidemics--,danish rule1 #achj4 #acij-adac ,death of old ,epidemics--,norse trade--,close of traditions1 c4 intercourse with ,norway4 ------------ ,dark ,age4 #adac-aecj ,only ,medieval poetry ,isolation from flourishes4 ,continent--,english trade4 ------------ ,,iii4 ,reformation--,absolute ,rule--,decay4 #cbj years4 ,reformation4 #aecj-aege ,,odd--,printing--,third era ,religious struggle--,new of phonetic change4 organization--,hanse trade ------------ ,renaissance4 #aege-afdj ,first antiquarians4 ,danish monopoly--,pirates' ravages4 #afdj-agjj ,,hallgrim--,paper copies taken4 ------------ ,gradual ,decay4 #agjj-agcj ,,jon ,,vidalin--,arni ,i ,d _/ ,smallpox kills one-third ,magnusson--,,mss4 taken n e population1 #agjg4 abroad4 c c ,great famine1 #aj1jjj die1 #agcj-agfh ,eggert ,olafsson4 r a #agei--,sheep plague1 e y #agfb--;,eruption1 #agfe #agfh-ahjj ,finn ,jonsson--,icelandic a 4 ,great eruption1 #aghc4 scholars abroad4 s ,beginnings of recovery-- #ahjj-ahej ,rationalistic i ,travellers make known island movement--,european n to ,europe--,free constitution influences first felt4 g in ,denmark1 #ahdh4 ------------ ,,iv4 ,modern ,iceland4 ,recovery of ,iceland4 #ahej-ahgd ,modern thought and ,increasing wealth and population-- learning--,icelandic ,free trade1 #ahed--;,jon ,sigurdsson scholars abroad and home rule struggle4 #ahgd ,home rule granted4 ---------------------------------------- ------------------------------------ ,organization4 ,the unit of ,icelandic politics was the homestead with its franklin-owner 7buendi71 its primal organization the hundred-moot 7thing71 its tie the goor 7godar7 or chieftainship4 ,the chief who had led a band of kinsmen and dependants to the new land1 taken a claim there1 and parcelled it out among them1 naturally became their leader1 presiding as priest at the temple feasts and sacrifices of heathen times1 acting as speaker of their moot1 and as their representative towards the neighbouring chiefs4 ,he was not a feudal lord nor a local sheriff1 for any franklin could change his goor when he would1 and the rights of judgment by peers were in full use2 moreover1 the office could be bequeathed1 sold1 divided or pledged by the possessor2 still the goi had considerable power as long as the commonwealth lasted4 ,disputes between neighbouring chiefs and their clients1 and uncertainty as to the law1 brought about the ,constitution of ,ulfliot 7c4 #icj71 which appointed a central moot for the whole island1 the ,althing1 and a speaker to speak a single law 7principally that followed by the ,gula-moot in ,norway72 the ,reforms of ,thord ,gellir 7#ifd71 settling a fixed number of moots and chieftaincies1 dividing the island into four quarters 7thus characterized by ,ari3 north1 thickest settled1 most famous2 east1 first completely settled2 south1 best land and greatest chiefs2 west1 remarkable for noble families71 to each of which a head-court1 the quarter-court1 was assigned2 and the ,innovations of ,skapti 7ascribed in the saga to ,nial7 the ,law-,speaker 7d4 #ajcj71 who set up a fifth court as the ultimate tribunal in criminal matters1 and strengthened the community against the chiefs4 ,but here constitutional growth ceased3 the law-making body made few and unimportant modifications of custom2 the courts were still too weak for the chiefs who misused and defied them2 the speaker's power was not sufficiently supported to enable him to be any more than a highly respected lord chief justice1 whereas he ought to have become a justiza if anarchy was to be avoided2 even the ecclesiastical innovations1 while they secured peace for a time1 provoked in the end the struggles which put an end to the commonwealth4 ,christianity was introduced c4 #ajjj4 ,tithes were established in #ajif1 and an ecclesiastical code made c4 #aabe4 ,the first disputes about the jurisdiction of the clergy were moved by ,gudmund in the #acth century1 bringing on a civil war1 while the questions of patronage and rights over glebe and mortmainland occupied ,bishop ,arni and his adversaries fifty years afterwards1 when the land was under ,norwegian viceroys and ,norwegian law4 ,for the civil wars broke down the great houses who had monopolized the chieftaincies2 and after violent struggles 7in which the ,sturlungs of the first generation perished at ,orlygstad1 #abch1 and ,reykiaholt1 #abda1 while of the second generation ,thord ,kakali was called away by the king in #abej1 and ,thorgils ,skardi slain in #abeh7 the submission of the island to ,norway quarter after quarter1 took place in #abfb-abfd1 under ,gizur's auspices1 and the old ,common ,law was replaced by the ,new ,norse ,code ,ironside in #abga4 ,the political life and law of the old days is abundantly illustrated in the sagas 7especially ,eyrbyggia1 ,hamsa-,thori1 ,reykdla1 ,hrafnkell1 and ,niala71 the two collections of law-scrolls 7,codex ,regius1 c4 #abce1 and ,stadarhol's ,book1 c4 #abga71 the ,libellus1 the ,liberfragments1 and the ,landnamabk of ,ari1 and the ,diplomatarium4 ,k4 ,maurer has made the subject his own in his ,beitrge1 ,island1 ,grgs1 c4 ,the medieval ,icelandic church had two bishoprics1 ,skalholt 7,s41 ,w41 and ,e47 #ajef1 and ,holar 7,n47 #aajf1 and about #age parishes 7two-thirds of which belonged to the southern bishopric74 ,they belonged to the metropolitan see of ,bremen1 then to ,lund1 lastly to ,nidaros1 #abcg4 ,there were several religious foundations3 ,thingore 7founded #aacc71 ,thwera 7#aaee71 ,hitardale 7c4 #aaff71 ,kirkby ,nunnery 7#aahd71 ,stad ,nunnery 7#abif71 and ,saurby 7c4 #abjj7 were ,benedictine1 while ,ver 7#aafh71 ,flatey after ,holyfell 7#aagb71 ,videy 7#abbf71 ,madderfield ,priory 7#abif71 and ,skrid ,priory 7#adth century7 were ,augustinian4 ,the bishops1 elected by the people at the ,althing till #abcg1 enjoyed considerable power2 two1 ,thorlak of ,skalholt and ,john of ,holar1 were publicly voted saints at the ,althing1 and one1 ,gudmund1 received the title of ,good by decree of the bishop and chapter4 ,full details as to ecclesiastical history will be found in the ,biskupasgur 7edited by ,dr ,vigfusson74 ,mode of life4 ,iceland was not agricultural but pastoral1 depending upon flocks ,mode of and herds for subsistence1 for1 though rye and other grain would grow in favoured localities1 the hay1 self-sown1 was the only regular crop4 ,in some districts the fisheries and fowling were of importance1 but nine-tenths of the population lived by their sheep and cattle4 ,life on each homestead was regularly portioned out3 out door occupations--fishing1 shepherding1 fowling1 and the hay-making and fuel-gathering--occupying the summer2 while indoor business--weaving1 tool-making1 c4--filled up the long winter4 ,the year was broken by the spring feasts and moots1 the great ,althing meeting at midsummer1 the marriage and arval gatherings after the summer1 and the long yule feasts at midwinter4 ,there were but two degrees of men1 free and unfree1 though only the franklins had any political power2 and1 from the nature of the life1 social intercourse was unrestrained and unfettered2 goi and thrall lived the same lives1 ate the same food1 spoke the same tongue1 and differed little in clothing or habits4 ,the thrall had a house of his own and was rather villein or serf than slave1 having rights and a legal price by law4 ,during the heathen days many great chiefs passed part of their lives in ,norway at the king's court1 but after the establishment of ,christianity in ,iceland they kept more at home1 visiting the continent1 however1 for purposes of state1 suits with clergy1 c4 ,trade was from the first almost entirely in foreign 7,norse7 hands4 ,the introduction of a church system brought little change4 ,the great families put their members into orders1 and so continued to enjoy the profits of the land which they had given to the church2 the priests married and otherwise behaved like the franklins around them in everyday matters1 farming1 trading1 going to law like laymen4 ,effects of the ,union4 ,life in the commonwealth was turbulent and anarchic1 but free and varied2 it produced men of mark1 and fostered bravery1 adventure and progress4 ,but on the union with ,norway all this ceased1 and there was left but a low dead level of poor peasant proprietors careless of all save how to live by as little labour as possible1 and pay as few taxes as they could to their foreign rulers4 ,the island received a foreign governor 7,earl1 ,hirdstjori or ,stiptamtsmadr as he was successively called71 and was parcelled out into counties 7sslur71 administered by sheriffs 7sslumadr7 appointed by the king4 ,a royal court took the place of the ,althing courts2 the local business of the local things was carried out by the 7hreppstjri7 bailiff1 a subordinate of the sheriff2 and the goor1 things1 quarter-courts1 trial by jury1 c41 were swept away by these innovations4 ,the power of the crown was increased by the confiscation of the great ,sturlung estates1 which were underleased to farmers1 while the early falling off of the ,norse trade threatened to deprive the island of the means of existence2 for the great epidemics and eruptions of the #adth century had gravely attacked its pastoral wealth and ruined much of its pasture and fishery4 ,the union of the ,three ,crowns transferred the practical rule of ,iceland to ,denmark in #abhj1 and the old ,treaty of ,union1 by which the island had reserved its essential rights1 was disregarded by the absolute ,danish monarchs2 but1 though new taxation was imposed1 it was rather their careless neglect than their too active interference that damaged ,iceland's interests4 ,but for an ,english trade1 which sprang up out of the half-smuggling1 half-buccaneering enterprise of the ,bristol merchants1 the island would have fared badly1 for during the whole of the #aeth century their trade with ,england1 exporting sulphur1 eiderdown 7of which the ,english taught them the value71 wool1 and salt stock-fish1 and importing as before wood1 iron1 honey1 wine1 grain and flax goods1 was their only link with the outer world4 ,this period of ,iceland's existence is eventless3 she had got peace but with few of its blessings2 all spirit seemed to have died with the commonwealth2 even shepherding and such agriculture as there had been sank to a lower stage2 wagons1 ploughs and carts went out of use and knowledge2 architecture in timber became a lost art1 and the fine carved and painted halls of the heathen days were replaced by turf-walled barns half sunk in the earth2 the large decked luggers of the old days gave way to small undecked fishing-boats4 ,the ,reformation4 ,the ,reformation in ,iceland wakened men's minds1 but it left their circumstances little changed4 ,though the fires of martyrdom were never lighted in ,iceland1 the story of the easily accepted ,reformation is not altogether a pleasant one4 ,when it was accomplished1 the little knot of able men who came to the front did much in preserving the records of the past1 while ,odd and ,hallgrim exhibit the noblest impulses of their time4 ,while there was this revolution in religion a social and political revolution never came to ,iceland4 ,the ,hanse trade replaced the ,english for the worse2 and the ,danish monopoly which succeeded it when the ,danish kings began to act again with vigour was still less profitable4 ,the glebes and hospital lands were a fresh power in the hands of the crown1 and the subservient ,lutheran clergy became the most powerful class in the island1 while the system of under-leasing at rackrent and short lease with unsecured tenant right extended over at least a quarter of the better land4 ,decadence4 ,a new plague1 that of the ,english1 ,gascon and ,algerine pirates1 marked the close of the #afth century and opening of the #agth1 causing widespread panic and some devastation in #aegi1 #afac-afaf and #afbg4 ,nothing points more to the helplessness of the natives' condition than their powerlessness against these foes4 ,but the #ahth century is the most gloomy in ,iceland's annals4 ,smallpox1 famine1 sheep disease1 and the eruptions of #agfe and #aghc follow each other in terrible succession4 ,against such visitations1 which reduced the population by about a fourth1 little could be done4 ,the few literary men1 whose work was done and whose books were published abroad1 were only concerned with the past1 and ,jon ,vidalin is the one man of mark1 beside ,eggert ,olafsson1 who worked and wrote for his own generation4#e ,modern times4 ,gradually the ideas which were agitating ,europe spread through ,scandinavia into ,iceland1 and its claims were more respectfully listened to4 ,the continental system1 which1 by its leading to the blockade of ,denmark1 threatened to starve ,iceland1 was neutralized by special action of the ,british government4 ,trade and fishery grew a little brisker1 and at length the turn came4 ,the rationalistic movement1 headed by ,magnus ,stephenson1 a patriotic1 narrow-minded lawyer1 did little good as far as church reform went1 but was accompanied by a more successful effort to educate the people4 ,a ,useful ,knowledge ,society was formed and did some honest work4 ,newspapers and periodicals were published1 and the very stir which the ecclesiastical disputes encouraged did good4 ,when free trade came1 and when the free constitution of ,denmark had produced its legitimate effects1 the endeavours of a few patriots such as ,jon ,sigurdsson were able to push on the next generation a step further4 ,questions of a modern political complexion arose2 the cattle export controversy and the great home rule struggle began4 ,after thirty years' agitation home rule was conceded in #ahgd 7see above1 ,government74 7,f4 ,y4 ,p47 ,,ancient ,,literature ,poetry4--,iceland has always borne a high renown for song1 but has never produced a poet of the highest order1 the qualities which in other lands were most sought for and admired in poetry being in ,iceland lavished on the saga1 a prose epic1 while ,icelandic poetry is to be rated very high for the one quality which its authors have ever aimed at--melody of sound4 ,to these generalizations there are few exceptions1 though ,icelandic literature includes a group of poems which possess qualities of high imagination1 deep pathos1 fresh love of nature1 passionate dramatic power1 and noble simplicity of language which ,icelandic poetry lacks4 ,the solution is that these poems do not belong to ,iceland at all4 ,they are the poetry of the ,western ,islands4 ,it was among the ,scandinavian colonists of the ,british coasts that in the first generations after the colonization of ,iceland therefrom a magnificent school of poetry arose1 to which we owe works that for power and beauty can be paralleled in no ,teutonic language till centuries after their date4 ,to this school1 which is totally distinct from the ,icelandic1 ran its own course apart and perished before the #acth century1 the following works belong 7of their authors we have scarcely a name or two2 their dates can be rarely exactly fixed1 but they lie between the beginning of the #ith and the end of the #ajth centuries71 classified into groups3-- 7a7 ,the ,helgi trilogy 7last third lost save a few verses1 but preserved in prose in ,hromund ,gripsson's ,saga71 the ,raising of ,anganty and ,death of ,hialmar 7in ,hervarar ,saga71 the fragments of a ,volsung ,lay 7,volsungakiraa7 7part interpolated in earlier poems1 part underlying the prose in ,volsunga ,saga71 all by one poet1 to whom ,dr ,vigfusson would also ascribe ,vlusp1 ,vegtamskvia1 rymskvia1 ,grtta ,song and ,vlundarkvia4 7b7 ,the ,dramatic ,poems3--,flyting of ,loki1 the ,fr ,skirnis1 the ,harbarslio and several fragments1 all one man's work1 to whose school belong1 probably1 the ,lay underlying the story of ,ivar's death in ,skioldunga ,saga4 7c7 ,the ,didactic ,poetry3--,grmnisml1 ,vafprunisml1 ,alvssmal1 c4 7d7 ,the ,genealogical and ,mythological ,poems3--,hyndluljo written for one of the ,haurda-,kari family1 so famous in the ,orkneys2 ,ynglingatal and ,haustlong1 by ,thiodolf of ,hvin2 ,rig's ,thul1 c4 7e7 ,the ,dirges and ,battle ,songs--such as that on ,hafur-firth ,battle ,hrafnsmal1 by ,thiodolf of ,hvin or ,thorbjrn ,hornklofi1 shortly after #hgj2 ,eirik's ,dirge 7,erksml7 between #iej and #ifi2 the ,dart-,lay on ,clontarf ,battle 7#ajad72 ,barka-mal 7fragments of which we have1 and paraphrase of more is found in ,hrolf ,kraki's ,saga and in ,saxo74 ,there are also fragments of poems in ,half's ,saga1 ,asmund ,kappa-,bana's ,saga1 in the ,latin verses of ,saxo1 and the ,shield ,lays 7,ragnarsdrapa7 by ,bragi1 c41 of this school1 which closes with the ,sun-,song1 a powerful ,christian ,dantesque poem1 recalling some of the early compositions of the ,irish ,church1 and with the #abth-century ,lay of ,ragnar1 ,lay of ,starkad1 ,the ,proverb ,song 7,havamal7 and ,krakumal1 to which we may add those singular ,gloss-poems1 the ulur1 which also belong to the ,western ,isles4 ,to ,greenland1 ,iceland's farthest colony1 founded in the #ajth century1 we owe the two ,lays of ,atli1 and probably ,hymiskvtia1 which1 though of a weirder1 harsher cast1 yet belong to the ,western ,isles school and not to ,iceland4 ,in form all these poems belong to two or three classes3--kvia1 an epic cantilena2 tl1 a genealogical poem2 drapa1 songs of praise1 c41 written in modifications of the old ,teutonic metre which we know in ,beowulf2 galdr and lokkr1 spell and charm songs in a more lyric measure2 and ml1 a dialogue poem1 and liod1 a lay1 in elegiac measure suited to the subject4 ,the characteristics of this ,western school are no doubt the result of the contact of ,scandinavian colonists of the viking-tide1 living lives of the wildest adventure1 with an imaginative and civilized race1 that exercised upon them a very strong and lasting influence 7the effects of which were also felt in ,iceland1 but in a different way74 ,the frequent intermarriages which mingled the best families of either race are sufficient proof of the close communion of ,northmen and ,celts in the #ith and #ajth centuries1 while there are in the poems themselves traces of ,celtic mythology1 language and manners4#f ,when one turns to the early poetry of the ,scandinavian continent1 preserved in the rune-staves on the memorial stones of ,sweden1 ,norway and ,denmark1 in the didactic ,havamal1 the ,great ,volsung ,lay 7i4e4 ,sigurd ,,ii41 ,fafnis's ,lay1 ,sigrdrifa's ,lay7 and ,hamdismal1 all continental1 and all entirely consonant to the remains of ,old ,english poetry in metre1 feeling and treatment1 one can see that it is with this school that the ,icelandic makers are in sympathy1 and that from it their verse naturally descends4 ,while shrewdness1 plain straightforwardness1 and a certain stern way of looking at life are common to both1 the ,icelandic school adds a complexity of structure and ornament1 an elaborate mythological and enigmatical phraseology1 and a regularity of rhyme1 assonance1 luxuriance1 quantity and syllabification1 which it caught from the ,latin and ,celtic poets1 and adapted with exquisite ingenuity to its own main object1 that of securing the greatest possible beauty of sound4 ,the first generations of ,icelandic poets resemble in many ways the later troubadours2 the books of the kings and the sagas are full of their strange lives4 ,men of good birth 7nearly always1 too1 of ,celtic blood on one side at least71 they leave ,iceland young and attach themselves to the kings and earls of the north1 living in their courts as their henchmen1 sharing their adventures in weal and woe1 praising their victories1 and hymning their deaths if they did not fall by their sides--men of quick passion1 unhappy in their loves1 jealous of rival poets and of their own fame1 ever ready to answer criticism with a satire or with a sword-thrust1 but clinging through all to their art1 in which they attained most marvellous skill4 ,such men were ,egil1 the foe of ,eirik ,bloodaxe and the friend of thelstan2 ,kormak1 the hot-headed champion2 ,eyvind1 ,king ,haakon's poet1 called ,skaldaspillir1 because he copied in his dirge over that king the older and finer ,erksml2 ,gunnlaug1 who sang at thelred's court1 and fell at the hands of a brother bard1 ,hrafn2 ,hallfred1 ,olaf ,tryggvason's poet1 who lies in ,iona by the side of ,macbeth2 ,sighvat1 ,saint ,olafs henchman1 most prolific of all his comrades2 ,thormod1 ,coalbrow's poet1 who died singing after ,sticklestad battle2 ,ref1 ,ottar the ,black1 ,arnor the earls' poet1 and1 of those whose poetry was almost confined to ,iceland1 ,gretti1 ,biorn the ,hitdale champion1 and the two model ,icelandic masters1 ,einar ,skulason and ,markus the ,lawman1 both of the #abth century4 ,it is impossible to do more here than mention the names of the most famous of the long roll of poets which are noted in the works of ,snorri and in the two ,skalda-tal4 ,they range from the rough and noble pathos of ,egil1 the mystic obscurity of ,kormak1 the pride and grief of ,hallfred1 and the marvellous1 fluency of ,sighvat1 to the florid intricacy of ,einar and ,markus4 ,the art of poetry stood to the ,icelanders in lieu of music2 scarcely any prominent man but knew how to turn a mocking or laudatory stanza1 and down to the fall of the commonwealth the accomplishment was in high request4 ,in the literary age the chief poets belong to the great ,sturlung family1 ,snorri and his two nephews1 ,sturla and ,olaf1 the ,white ,poet1 being the most famous makers of their day4 ,indeed1 it is in ,snorri's ,edda1 a poetic grammar of a very perfect kind1 that the best examples of the whole of northern poetry are to be found4 ,the last part1 ,hattatal1 a treatise on metre1 was written for ,earl ,skuli about #abbb1 in imitation of ,earl ,rognvald and ,hall's ,hattalykill 7,clavis metrica7 of #aaej4 ,the second part1 ,skaldskapar-mal1 a gradus of synonyms and epithets1 which contains over #bdj quotations from #fe poets1 and #aj anonymous lays--a treasury of verse--was composed c4 #abcj4 ,the first part1 an exquisite sketch of northern mythology1 ,gylfa-ginning1 was probably prefixed to the whole later4 ,there is some of ,sturla's poetry in his ,islendinga ,saga1 and verses of ,snorri occur in the ,grammatical ,treatise on figures of speech1 c41 of ,olaf1 which contains about one hundred and forty quotations from various authors1 and was written about #abej4 ,besides those sources1 the ,kings' ,lives of ,snorri and later authors contain a great deal of verse by ,icelandic poets4 ,king ,harold ,sigurdsson1 who fell at ,stamford ,bridge #ajff1 was both a good critic and composed himself4 ,many tales are told of him and his poet visitors and henchmen4 ,the ,icelandic sagas also comprise much verse which is partly genuine1 partly the work of the #abth and #acth century editors4 ,thus there are genuine pieces in ,nial's ,saga 7chaps4 #cd1 #gh1 #ajc1 #abf1 #adf71 in ,eyrbyggia1 ,laxdla1 ,egil's ,saga 7part only71 ,grettla 7two and a half stanzas1 cf4 ,landnamabk71 ,biorn's ,saga1 ,gunnlaug's ,saga1 ,havard's ,saga1 ,kormak's ,saga1 ,viga-,glum's ,saga1 ,erik the ,red's ,saga and ,fostbrdra ,saga4 ,in ,nial's1 ,gisli's and ,droplaug's ,sons' ,sagas there is good verse of a later poet1 and in many sagas worthless rubbish foisted in as ornamental4 ,to these may be added two or three works of a semi-literary kind1 composed by learned men1 not by heroes and warriors4 ,such are ,konunga-tl1 ,hugsvinnsml 7a paraphrase of ,cato's ,distichs71 ,merlin's ,prophecy 7paraphrased from ,geoffrey of ,monmouth by ,gunnlaug the monk71 ,jomsvikinga-drapa 7by ,bishop ,ketil71 and the ,islendinga-drapa1 which has preserved brief notices of several lost sagas concerning ,icelandic worthies1 with which ,gudmundar-drapa1 though of the #adth century1 may be also placed4 ,just as the change of law gave the death-blow to an already perishing commonwealth1 so the rush of medieval influence1 which followed the union with ,norway1 completed a process which had been in force since the end of the #aath century1 when it overthrew the old ,icelandic poetry in favour of the rimur4 ,the introduction of the danz1 ballads 7or fornkvdi1 as they are now called7 for singing1 with a burden1 usually relating to a love-tale1 which were immensely popular with the people and performed by whole companies at weddings1 yule feasts and the like1 had relegated the regular ,icelandic poetry to more serious events or to the more cultivated of the chiefs4 ,but these jigs1 as the ,elizabethans would have called them1 dissatisfied the popular ear in one way3 they were1 like old ,english ballads1 which they closely resembled1 in rhyme1 but void of alliteration1 and accordingly they were modified and replaced by the rimur1 the staple literary product of the #aeth century4 ,these were rhymed but also alliterative1 in regular form1 with prologue or mansong 7often the prettiest part of the whole71 main portion telling the tale 7mostly derived in early days from the ,french romances of the ,carlovingian1 ,arthurian or ,alexandrian cycles1 or from the mythic or skrk-sgur71 and epilogue4 ,their chief value to us lies in their having preserved versions of several ,french poems now lost1 and in their evidence as to the feelings and bent of ,icelanders in the ,dark ,age of the island's history4 ,the ring and melody which they all possess is their chief beauty4 ,of the earliest1 ,olafsrima1 by ,einar ,gilsson 7c4 #acej71 and the best1 the ,aristophanic ,skda-rima 7c4 #adcj71 by ,einar ,fostri1 the names may be given4 ,rimur on sacred subjects was called diktur2 of these1 on the legends of the saints' lives1 many remain4 ,the most notable of its class is the ,lilia of ,eystein ,asgrimsson1 a monk of ,holyfell 7c4 #acej71 a most sweet sounding song4 ,later the poems of the famous ,jon ,arason 7b4 #adhd71 last ,catholic bishop of ,holar 7c4 #aecj71 ,liomr 7gleam7 and ,pslargrtr 7passion-tears71 deserve mention4 ,arason is also celebrated as having introduced printing into ,iceland4 ,taste has sunk since the old days2 but still this rimur poetry is popular and genuine4 ,moreover1 the very prosaic and artificial verse of ,sturla and the last of the old school deserved the oblivion which came over them1 as a casual perusal of the stanzas scattered through ,islendinga will prove4 ,it is interesting to notice that a certain number of kenningar 7poetical paraphrases7 have survived from the old school even to the present day1 though the mass of them have happily perished4 ,the change in the phonesis of the language is well illustrated by the new metres as compared with the old ,icelandic drott-kvdi in its varied forms4 ,most of the older rimur and diktur are as yet unprinted4 ,many of the fornkvdi are printed in a volume of the old ,nordiske ,litteralur-,samfund4 ,the effects of the ,reformation was deeply felt in ,icelandic literature1 both prose and verse4 ,the name of ,hallgrim ,petursson1 whose ,passion-hymns1 the flower of all ,icelandic poetry1 have been the most popular composition in the language1 is foremost of all writers since the second change of faith4 ,the gentle sweetness of thought1 and the exquisite harmony of wording in his poems1 more than justify the popular verdict4 ,his ,hymns were finished in #affj and published in #afff1 two great ,protestant poets thus being contemporaries4 ,a collection of ,reformation hymns1 adapted1 many of them1 from the ,german1 the ,holar-book1 had preceded them in #afai4 ,there was a good deal of verse-writing of a secular kind1 far inferior in every way1 during this period4 ,in spite of the many physical distresses that weighed upon the island1 ballads 7fornkvdi7 were still written1 ceasing about #agej1 rimur composed1 and more elaborate compositions published4 ,the most notable names are those of the improvisatore ,stephen the ,blind2 ,thorlak ,gudbrandsson1 author of ,ulfar-,rmur1 d4 #agjg2 ,john ,magnusson1 who wrote ,hristafla1 a didactic poem2 ,stefan ,olafsson1 composer of psalms1 rimur1 c41 d4 #afhh2 ,gunnar ,plsson1 the author of ,gunnarslag1 often printed with the ,eddic poems1 c4 #agia2 and ,eggert ,olafsson1 traveller1 naturalist and patriot1 whose untimely death in #agfh was a great loss to his country4 ,his ,bunadar-balkr1 a ,georgic written1 like ,tusser's ,points1 with a practical view of raising the state of agriculture1 has always been much prized4 ,paul ,vidalin's ditties are very nave and clever4 ,of later poets1 down to more recent times1 perhaps the best was ,sigurd of ,broadfirth1 many of whose prettiest poems were composed in ,greenland like those of ,jon ,biarnisson before him1 c4 #agej2 ,john ,thorlaksson's translation of ,milton's great epic into ,eddic verse is praiseworthy in intention1 but1 as may be imagined1 falls far short of its aim4 ,he also turned ,pope's ,essay on ,man and ,klopstock's ,messiah into ,icelandic4 ,benedikt ,grndal tried the same experiment with ,homer in his ,ilion's ,kvdi1 c4 #ahbe4 ,there is a fine prose translation of the ,odyssey by ,sweinbjrn ,egillson1 the lexicographer1 both faithful and poetic in high degree4 ,sagas4--,the real strength of ancient ,icelandic literature is shown in its most indigenous growth1 the ,saga 7see also ,,saga74 ,this is1 in its purest form1 the life of a hero1 composed in regular form1 governed by fixed rules1 and intended for oral recitation4 ,it bears the strongest likeness to the epic in all save its unversified form2 in both are found1 as fixed essentials1 simplicity of plot1 chronological order of events1 set phrases used even in describing the restless play of emotion or the changeful fortunes of a fight or a storm1 while in both the absence of digression1 comment or intrusion of the narrator's person is invariably maintained4 ,the saga grew up in the quieter days which followed the change of faith 7#ajjb71 when the deeds of the great families' heroes were still cherished by their descendants1 and the exploits of the great kings of ,norway and ,denmark handed down with reverence4 ,telling of stories was a recognized form of entertainment at all feasts and gatherings1 and it was the necessity of the reciter which gradually worked them into a regular form1 by which the memory was relieved and the artistic features of the story allowed to be more carefully elaborated4 ,that this form was so perfect must be attributed to ,irish influence1 without which indeed there would have been a saga1 but not the same saga4 ,it is to the west that the best sagas belong2 it is to the west that nearly every classic writer whose name we know belongs2 and it is precisely in the west that the admixture of ,irish blood is greatest4 ,in comparing the ,irish tales with the saga1 there will be felt deep divergencies in matter1 style and taste1 the richness of one contrasting with the chastened simplicity of the other2 the one's half-comic1 half-earnest bombast is wholly unlike the other's grim humour2 the marvellous1 so unearthly in the one1 is almost credible in the other2 but in both are the keen grasp of character1 the biting phrase1 the love of action and the delight in blood which almost assumes the garb of a religious passion4 ,when the saga had been fixed by a generation or two of oral reciters1 it was written down2 and this stereotyped the form1 so that afterwards when literary works were composed by learned men 7such as ,abbot ,karl's ,swerri's ,saga and ,sturla's ,islendinga7 the same style was adopted4 ,icelandic sagas4 ,taking first the sagas relating to ,icelanders1 of which some thirty-five or forty remain out of thrice that number1 they were first written down between #aadj and #abbj1 in the generation which succeeded ,ari and felt the impulse his books had given to writing1 on separate scrolls1 no doubt mainly for the reciter's convenience2 they then went through the different phases which such popular compositions have to pass in all lands--editing and compounding 7#abbj-abfj71 padding and amplifying 7#abfj-acjj71 and finally collection in large ,,mss4 7#adth century74 ,sagas exist showing all these phases1 some primitive and rough1 some refined and beautified1 some diluted and weakened1 according as their copyists have been faithful1 artistic or foolish2 for the first generation of ,,mss4 have all perished4 ,we have also complex sagas put together in the #acth century out of the scrolls relating to a given locality1 such a group as still exists untouched in ,vapnfirdinga being fused into such a saga as ,niala or ,laxdla4 ,of the authors nothing is known2 we can only guess that some belong to the ,sturlung school4 ,according to subject they fall into two classes1 those relating to the older generation before ,christianity and those telling of ,st ,olaf's contemporaries2 only two fall into a third generation4 ,beginning with the sagas of the west1 most perfect in style and form1 the earliest in subject is that of ,gold-,thori 7c4 #icj71 whose adventurous career it relates2 ,hensa-orissaga tells of the burning of ,blund-,ketil1 a noble chief1 an event which led to ,thord ,gelli's reforms next year 7c4 #ifd72 ,gislasaga 7#ifj-ihj7 tells of the career and death of that ill-fated outlaw2 it is beautifully written1 and the verses by the editor 7#acth century7 are good and appropriate2 ,hord's ,saga 7#ihj7 is the life of a band of outlaws on ,whalesfirth1 and especially of their leader ,hord4 ,of later subject are the sagas of ,havard and his revenge for his son1 murdered by a neighbouring chief 7#iig-ajjb72 of the ,heiarirgasaga 7#iij-ajad71 a typical tale of a great blood feud1 written in the most primitive prose2 of ,gunnlaug and ,hrafn 7,gunnlaugssaga ,ormstungu1 #ihj-ajjh71 the rival poets and their ill-starred love4 ,the verse in this saga is important and interesting4 ,to the west also belong the three great complex sagas ,egla1 ,eyrbyggia and ,laxdla4 ,the first 7#hgj-ihj71 after noticing the migration of the father and grandfather of the hero poet ,egil1 and the origin of the feud between them and the kings of ,norway1 treats fully of ,egil's career1 his enmity with ,eirik ,bloodaxe1 his service with thelstan1 and finally1 after many adventures abroad1 of his latter days in ,iceland at ,borg1 illustrating very clearly what manner of men those great settlers and their descendants were1 and the feelings of pride and freedom which led them to ,iceland4 ,the style is that of ,snorri1 who had himself dwelt at ,borg4 ,eyrbyggia 7#hij-ajca7 is the saga of politics1 the most loosely woven of all the compound stories4 ,it includes a mass of information on the law1 religion1 traditions1 c41 of the heathen days in ,iceland1 and the lives of ,eric1 the real discoverer of ,greenland1 ,biorn of ,broadwick1 a famous chief1 and ,snorri1 the greatest statesman of his day4 ,dr ,vigfusson would ascribe its editing and completion to ,sturla the ,lawman1 c4 #abej4 ,laxdla 7#iaj-ajbf7 is the saga of ,romance4 ,its heroine ,gudrun is the most famous of all ,icelandic ladies4 ,her love for ,kiartan the poet1 and his career abroad1 his betrayal by his friend ,bolli1 the sad death of ,kiartan at his hands1 the revenge taken for him on ,bolli1 whose slayers are themselves afterwards put to death1 and the end of ,gudrun1 who becomes an anchorite after her stormy life1 make up the pith of the story4 ,the contrast of the characters1 the rich style and fine dialogue which are so remarkable in this saga1 have much in common with the best works of the ,sturlung school4 ,of the north there are the sagas of ,kormak 7#icj-ifj71 most primitive of all1 a tale of a wild poet's love and feuds1 containing many notices of the heathen times2 of ,vatzdlasaga 7#hij-ihj71 relating to the settlement and the chief family in ,waterdale2 of ,hallfred the poet 7#iif-ajad71 narrating his fortune at ,king ,olafs court1 his love affairs in ,iceland1 and finally his death and burial at ,iona2 of ,reyk-dla 7#iij71 which preserves the lives of ,askell and his son ,viga-,skuti2 of ,svarf-dla 7#ihj-iij71 a cruel1 coarse story of the old days1 with some good scenes in it1 unfortunately imperfect1 chapters #a-aj being forged2 of ,viga-,glum 7#igj-iij71 a fine story of a heathen hero1 brave1 crafty and cruel4 ,to the north also belong the sagas of ,gretti the ,strong 7#ajaj-ajca71 the life and death of the most famous of ,icelandic outlaws1 the real story of whose career is mixed up with the mythical adventures of ,beowulf1 here put down to ,gretti1 and with late romantic episodes and fabulous folk-tales 7,dr ,vigfusson would ascribe the best parts of this saga to ,sturla2 its last editor1 whose additions would be better away1 must have touched it up about #acjj71 and the stories of the ,ljosvetningasaga 7#ajji-ajfj74 ,gudmund the ,mighty and his family and neighbours are the heroes of these tales1 which form a little cycle4 ,the ,banda-manna saga 7#ajej-ajfj71 the only comedy among the sagas1 is also a northern tale2 it relates the struggles of a plebeian who gets a chieftancy against the old families of the neighbourhood1 whom he successfully outwits2 l-kofra attr is a later imitation of it in the same humorous strain4 ,the sagas of the north are rougher and coarser than those of the west1 but have a good deal of individual character4 ,of tales relating to the east there survive the ,weapon-firth cycle--the tales of ,thorstein the ,white 7c4 #ijj71 of ,thorstein the ,staffsmitten 7c4 #ihe71 of ,gunnar ,thidrand's ,bane 7#ajjj-ajjh7 and of the ,weapon-firth ,men 7#ige-iij71 all relating to the family of ,hof and their friends and kin for several generations--and the story of ,hrafnkell ,frey's ,priest 7c4 #ifj71 the most idyllic of sagas and best of the eastern tales4 ,of later times there are ,droplaug's ,sons' ,saga 7#iig-ajjg71 written probably about #aaaj1 and preserved in the uncouth style of the original 7a brother's revenge for his brother's death is the substance of it2 ,brandkrossa attr is an appendix to it71 and the tales of ,thorstein ,hall of ,side's ,son 7c4 #ajad7 and his brother ,thidrandi 7c4 #iif71 which belong to the cycle of ,hall o' ,side's ,saga1 unhappily lost2 they are weird tales of bloodshed and magic1 with idyllic and pathetic episodes4 ,the sagas of the south are either lost or absorbed in that of ,nial 7#igj-ajad71 a long and complex story into which are woven the tales of ,gunnar ,nial1 and parts of others1 as ,brian ,boroimhe1 ,hall o' ,side1 c4 ,it is1 whether we look at style1 contents or legal and historical weight1 the foremost of all sagas4 ,it deals especially with law1 and contains the pith and the moral of all early ,icelandic history4 ,its hero ,nial1 type of the good lawyer1 is contrasted with its villain ,mord1 the ensample of cunning1 chicane1 and legal wrong doing2 and a great part of the saga is taken up with the three cases and suits of the divorce1 the death of ,hoskuld and the burning of ,nial1 which are given with great minuteness4 ,the number and variety of its dramatis personae give it the liveliest interest throughout4 ,the women ,hallgerda1 ,bergthora and ,ragnhild are as sharply contrasted as the men ,gunnar1 ,skarphedin1 ,flosi and ,kari4 ,the pathos of such tragedies as the death of ,gunnar and ,hoskuld and the burning is interrupted by the humour of the ,althing scenes and the intellectual interest of the legal proceedings4 ,the plot dealing first with the life and death of ,gunnar1 type of the chivalry of his day1 then with the burning of ,nial by ,flosi1 and how it came about1 and lastly with ,kari's revenge on the burners1 is the ideal saga-plot4 ,the author must have been of the east1 a good lawyer and genealogist1 and have composed it about #abej1 to judge from internal evidence4 ,it has been overworked by a later editor1 c4 #acjj1 who inserted many spurious verses4 ,of ,greenland and ,north ,america4 ,relating partly to ,iceland1 but mostly to ,greenland and ,vinland 7,n4 ,america71 are the ,floamannasaga 7#ihe-iij71 a good story of the adventures of ,thorgils and of the struggles of shipwrecked colonists in ,greenland1 a graphic and terrible picture2 and ,eirikssaga raua 7#iij-ajjj71 two versions1 one northern 7,flatey-book71 one western1 the better 7in ,hawk's ,book1 and ,,am4 #eeg71 the story of the discovery of ,greenland and ,vinland 7,america7 by the ,icelanders at the end of the #ith century4 ,later is the ,fostbrdrasaga 7#ajae-ajcj71 a very interesting story1 told in a quaint romantic style1 of ,thorgeir1 the reckless henchman of ,king ,olaf1 and how his death was revenged in ,greenland by his sworn brother the true-hearted ,thormod ,coalbrow's poet1 who afterward dies at ,sticklestad4 ,the tale of ,einar ,sookisson 7c4 #aabe7 may also be noticed4 ,the lost saga of ,poet ,helgi1 of which only fragments remain1 was also laid in ,greenland4 ,besides complete sagas there are embedded in the ,heimskringla numerous small ttir or episodes1 small tales of ,icelanders' adventures1 often relating to poets and their lives at the kings' courts2 one or two of these seem to be fragments of sagas now lost4 ,among the more notable are those of ,orm ,storolfsson1 ,ogmund ,dijtt1 ,halldor ,snorrason1 ,thorstein ,oxfoot1 ,hromund ,halt1 ,thorwald ,tasaldi1 ,svadi and ,arnor ,herlingar-nef1 ,audunn of ,westfirth1 ,sneglu-,halli1 ,hrafn of ,hrutfiord1 ,hreidar ,heimski1 ,gisli ,illugison1 ,ivar the poet1 ,gull-su ,thord1 ,einar ,skulason the poet1 ,mani the poet1 c4 ,the forged ,icelandic sagas appear as early as the #acth century4 ,they are very poor1 and either worked up on hints given in genuine stories or altogether apocryphal4 ,history4--,about the year of the battle of ,hastings was born ,ari ,froi ,thorgilsson 7#ajfg-aadh71 one of the blood of ,queen ,aud1 who founded the famous historical school of ,iceland1 and himself produced its greatest monument in a work which can be compared for value with the ,english ,domesday ,book4 ,nearly all that we know of the heathen commonwealth may be traced to the collections of ,ari4 ,it was he too that fixed the style in which history should be composed in ,iceland4 ,it was he that secured and put into order the vast mass of fragmentary tradition that was already dying out in his day4 ,and perhaps it is the highest praise of all to him that he wrote in his own ,danish tongue1 and so ensured the use of that tongue by the cultured of after generations4 ,ari's great works are ,konungabk1 or ,the ,book of ,kings1 relating the history of the kings of ,norway from the rise of the ,yngling dynasty down to the death of ,harald ,sigurdsson in the year of his own birth4 ,this book he composed from the dictation of old men such as ,odd ,kolsson1 from the genealogical poems1 and from the various dirges1 battle-songs and eulogia of the poets4 ,it is most probable that he also compiled shorter ,kings' ,books relating to ,denmark and perhaps to ,england4 ,the ,konungabk is preserved under the ,heimskringla of ,snorri ,sturloson1 parts of it almost as they came from ,ari's hands1 for example ,ynglinga and ,harald ,fairhair's ,saga1 and the prefaces stating the plan and critical foundations of the work1 parts of it only used as a framework for the magnificent superstructure of the lives of the two ,olafs1 and of ,harald ,hardrada and his nephew ,magnus the ,good4 ,the best text of ,ari's ,konungabk 7,ynglinga1 and the sagas down to but not including ,olaf ,tryggvason's7 is that of ,frisbk4 ,the ,book of ,settlements 7,landnamabk7 is a wonderful performance1 both in its scheme and carrying out4 ,it is divided into five parts1 the first of which contains a brief account of the discovery of the island2 the other four1 one by one taking a quarter of the land1 describe the name1 pedigree and history of each settler in geographical order1 notice the most important facts in the history of his descendants1 the names of their homesteads1 their courts and temples1 thus including mention of #djjj persons1 one-third of whom are women1 and #bjjj places4 ,the mass of information contained in so small a space1 the clearness and accuracy of the details1 the immense amount of life which is breathed into the whole1 astonish the reader1 when he reflects that this colossal task was accomplished by one man1 for his collaborator ,kolsegg merely filled up his plan with regard to part of the east coast1 a district with which ,ari in his western home at ,stad was little familiar4 ,landnamabk has reached us in two complete editions1 one edited by ,sturla1 who brought down the genealogies to his own grandfather and grandmother1 ,sturla and ,gudny1 and one by ,hawk1 who traces the pedigrees still later to himself4 ,ari also wrote a ,book of ,icelanders 7,islendingabk1 c4 #aabg71 which has perished as a whole1 but fragments of it are embedded in many sagas and ,kings' ,lives2 it seems to have been a complete epitome of his earlier works1 together with an account of the constitutional history1 ecclesiastical and civil1 of ,iceland4 ,an abridgment of the latter part of it1 the little ,libellus ,islandorum 7to which the title of the bigger ,liber--,islendingabk--is often given71 was made by the historian for his friends ,bishops ,ketil and ,thorlak1 for whom he wrote the ,liber 7c4 #aacg74 ,this charming little book is1 with the much later collections of laws1 our sole authority for the ,icelandic constitution of the commonwealth1 but1 much as it tells1 the lost ,liber would have been of still greater importance4 ,kristni-,saga1 the story of the christening of ,iceland1 is also a work of ,ari's1 overlaid by a later editor1 but often preserving ,ari's very words4 ,this saga1 together with several scattered tales of early ,christians in ,iceland before the change of faith 7#ajjb71 may have made up a section of the lost ,liber4 ,of the author of these works little is known4 ,he lived in quiet days a quiet life2 but he shows himself in his works1 as ,snorri describes him1 a man wise1 of good memory and a speaker of the truth4 ,if ,thucydides is justly accounted the first political historian1 ,ari may be fitly styled the first of scientific historians4 ,a famous contemporary and friend of ,ari is ,smund 7#ajef-aaca71 a great churchman1 whose learning so impressed his age that he got the reputation of a magician4 ,he was the friend of ,bishop ,john1 the founder of the great ,odd-,verjar family1 and the author of a ,book of ,kings from ,harald ,fairhair to ,magnus the ,good1 in which he seems to have fixed the exact chronology of each reign4 ,it is most probable that he wrote in ,latin4 ,the idea that he had anything to do with the poetic ,edda in general1 or the ,sun's ,song in particular1 is unfounded4 ,the flame which ,ari had kindled was fed by his successors in the #abth century4 ,eirik ,oddsson 7c4 #aaej7 wrote the lives of ,sigurd ,evil-deacon and the sons of ,harold ,gille1 in his ,hryggiar-,stykki 7,sheldrake71 of which parts remain in the ,,mss4 collections of ,kings' ,lives1 ,morkin-skinna1 c4 ,karl ,jonsson1 abbot of ,thingore1 the ,benedictine minister1 wrote 7c4 #aahd7 ,sverrissaga from the lips of that great king1 a fine racy biography1 with a style and spirit of its own4 ,bglunga-,sgur tell the story of the civil wars which followed ,sverri's death4 ,they are probably by a contemporary4 ,the ,latin ,lives of ,st ,olaf1 ,odd's in ,latin 7c4 #aage71 compiled from original authorities1 and the ,legendary ,life1 by another monk whose name is lost1 are of the medieval ,latin school of ,smund to which ,gunnlaug belonged4 ,snorri ,sturlason 7q4v47 was known to his contemporaries as a statesman and poet2 to us he is above all an historian4 ,snorri 7#aagi-abda7 wrote the ,lives of the ,kings 7,heimskringla71 from ,olaf ,tryggvason to ,sigurd the ,crusader inclusive2 and we have them substantially as they came from his hand in the ,great ,king ,olaf's ,saga2 ,st ,olaf's ,saga1 as in ,heimskringla and the ,stockholm ,,ms42 and the succeeding ,kings' ,lives1 as in ,hulda and ,hrokkinskinna1 in which1 however1 a few episodes have been inserted4 ,these works were indebted for their facts to ,ari's labours1 and to sagas written since ,ari's death2 but the style and treatment of them are ,snorri's own4 ,the fine ,thucydidean speeches1 the dramatic power of grasping character1 and the pathos and poetry that run through the stories1 along with a humour such as is shown in the ,edda1 and a varied grace of style that never flags or palls1 make ,snorri one of the greatest of historians4 ,here it should be noticed that ,heimskringla and its class of ,,mss4 7,eirspennil1 ,jofraskinna1 ,gullinskinna1 ,fris-bok and ,kringla7 do not give the full text of ,snorri's works4 ,they are abridgments made in ,norway by ,icelanders for their ,norwegian patrons1 the ,life of ,st ,olaf alone being preserved intact1 for the great interest of the ,norwegians lay in him1 but all the other ,kings' ,lives being more or less mutilated1 so that they cannot be trusted for historic purposes2 nor do they give a fair idea of ,snorri's style4 ,agrip is a #abth-century compendium of the ,kings' ,lives from ,harald ,fairhair to ,sverri1 by a scholastic writer of the school of ,smund4 ,as the only ,icelandic abridgment of ,norwegian history taken not from ,snorri but sources now lost1 it is of worth4 ,its real title is ,konunga-tal4 ,noregs ,konunga-tal1 now called ,fagrskinna1 is a ,norse compendium of the ,kings' ,lives from ,halfdan the ,black to ,sverri's accession1 probably written for ,king ,haakon1 to whom it was read on his death-bed4 ,it is an original work1 and contains much not found elsewhere4 ,as non-,icelandic it is only noticed here for completeness4 ,styrmi ,karason1 a contemporary of ,snorri's1 dying in #abde1 was a distinguished churchman 7lawman twice7 and scholar4 ,he wrote a ,life of ,st ,olaf1 now lost2 his authority is cited4 ,he also copied out ,landnamabk and ,sverri's ,life from his ,,mss41 of which surviving copies were taken4 ,sturla1 ,snorri's nephew1 wrote the ,hakonssaga and ,magnussaga at the request of ,king ,magnus1 finishing the first c4 #abfe1 the latter c4 #abhj4 ,king ,haakon's ,life is preserved in full2 of the other only fragments remain4 ,these are the last of the series of historic works which ,ari's labours began1 from which the history of ,norway for #ejj years must be gathered4 ,a few books relating the history of other ,scandinavian realms will complete this survey4 ,in ,skioldunga-bok was told the history of the early kings of ,denmark1 perhaps derived from ,ari's collections1 and running parallel to ,ynglinga4 ,the earlier part of it has perished save a fragment ,sogu-brot1 and citations and paraphrases in ,saxo1 and the mythical ,ragnar ,lodbrok's and ,gongu-,hrolf's ,sagas2 the latter part1 ,lives of ,harold ,bluetooth and the ,kings down to ,sveyn ,,ii41 is still in existence and known as ,skioldunga4 ,the ,knutssaga is of later origin and separate authorships1 parallel to ,snorri's ,heimskringla1 but earlier in date4 ,the ,lives of ,king ,valdemar and his ,son1 written c4 #aahe1 by a contemporary of ,abbot ,karl's1 are the last of this series4 ,the whole were edited and compiled into one book1 often quoted as ,skioldunga1 by a #acth-century editor1 possibly ,olaf1 the ,white ,poet1 ,sturla's brother1 guest and friend of ,king ,valdemar ,,ii4 ,jomsvikinga ,saga1 the history of the pirates of ,jom1 down to ,knut the ,great's days1 also relates to ,danish history4 ,the complex work now known as ,orkneyinga is made up of the ,earls' ,saga1 lives of the first great earls1 ,turf-,einar1 ,thorfinn1 c42 the ,life of ,st ,magnus1 founded partly on ,abbot ,robert's ,latin life of him 7c4 #aaej7 an ,orkney work1 partly on ,norse or ,icelandic biographies2 a ,mirade-book of the same saint2 the ,lives of ,earl ,rognwald and ,sveyn1 the last of the vikings1 and a few episodes such as the ,burning of ,bishop ,adam4 ,a scholastic sketch of the rise of the ,scandinavian empire1 the ,foundation of ,norway1 dating c4 #aabj1 is prefixed to the whole4 ,freyinga tells the tale of the conversion of the ,freys or ,faroes1 and the lives of its chiefs ,sigmund and ,leif1 composed in the #acth century from their separate sagas by an ,icelander of the ,sturlung school4 ,biographies4--,the saga has already been shown in two forms1 its original epic shape and its later development applied to the lives of ,norwegian and ,danish kings and earls1 as heroic but deeper and broader subjects than before4 ,in the #acth century it is put to a third use1 to tell the plain story of men's lives for their contemporaries1 after satisfying which demand it dies away for ever4 ,these biographies are more literary and medieval and less poetic than the ,icelandic sagas and king's lives2 their simplicity1 truth1 realism and purity of style are the same4 ,they run in two parallel streams1 some being concerned with chiefs and champions1 some with bishops4 ,the former are mostly found embedded in the complex mass of stories known as ,sturlunga1 from which ,dr ,vigfusson has extricated them1 and for the first time set them in order4 ,among them are the sagas of ,thorgils and ,haflidi 7#aaah-aaba71 the feud and peacemaking of two great chiefs1 contemporaries of ,ari2 of ,sturla 7#aaej-aahc71 the founder of the great ,sturlung family1 down to the settlement of his great lawsuit by ,jon ,loptsson1 who thereupon took his son ,snorri the historian to fosterage1--a humorous story but with traces of the decadence about it1 and glimpses of the evil days that were to come2 of the nundar-brennusaga 7#aahe-abjj71 a tale of feud and fire-raising in the north of the island1 the hero of which1 ,gudmund ,dyri1 goes at last into a cloister2 of ,hrafn ,sveinbiornsson 7#aaij-abac71 the noblest ,icelander of his day1 warrior1 leech1 seaman1 craftsman1 poet and chief1 whose life at home1 travels and pilgrimages abroad 7,hrafn was one of the first to visit ,becket's shrine71 and death at the hands of a foe whom he had twice spared1 are recounted by a loving friend in pious memory of his virtues1 c4 #abbj2 of ron ,hiorleifsson 7#abjj-abee71 a man whose strength1 courage and adventures befit rather a henchman of ,olaf ,tryggvason than one of ,king ,haakon's thanes 7the beginning of the feuds that rise round ,bishop ,gudmund are told here71 of the ,svinefell-men 7#abdh-abeb71 a pitiful story of a family feud in the far east of ,iceland4 ,but the most important works of this class are the ,islendinga ,saga and ,thorgils ,saga of ,lawman ,sturla4 ,sturla and his brother ,olaf were the sons of ,thord ,sturlason and his mistress ,thora4 ,sturla was born and brought up in prosperous times1 but his manhood was passed in the midst of strife1 in which his family fell one by one1 and he himself1 though a peaceful man who cared little for politics1 was more than once forced to fly for his life4 ,while in refuge with ,king ,magnus1 in ,norway1 he wrote his two sagas of that king and his father4 ,after his first stay in ,norway he came back in #abga1 with the new ,norse law-book1 and served a second time as lawman4 ,the ,islendinga must have been the work of his later years1 composed at ,fairey in ,broadfirth1 where he died1 #cjth ,july #abhd1 aged about seventy years4 ,the saga of ,thorgils ,skardi 7#abeb-abfa7 seems to have been the first of his works on ,icelandic contemporary history2 it deals with the life of his own nephew1 especially his career in ,iceland from #abeb to #abeh4 ,the second part of ,islendinga 7#abdb-abfb71 which relates to the second part of the civil war1 telling of the careers of ,thord ,kakali1 ,kolbein the ,young1 ,earl ,gizur and ,hrafn ,oddsson4 ,the end is imperfect1 there being a blank of some years before the fragmentary ending to which an editor has affixed a notice of the author's death4 ,the first part of ,islendinga 7#abjb-abdb7 tells of the beginning and first part of the civil wars1 the lives of ,snorri and ,sighvat1 ,sturla's uncles1 of his cousin and namesake ,sturla ,sighvatsson1 of ,bishop ,gudmund1 and ,thorwald ,gizursson1--the fall of the ,sturlungs1 and with them the last hopes of the great houses to maintain the commonwealth1 being the climax of the story4 ,sturla's power lies in his faithfulness to nature1 minute observance of detail and purity of style4 ,the great extent of his subject1 and the difficulty of dealing with it in the saga form1 are most skilfully overcome2 nor does he allow prejudice or favour to stand in the way of the truth4 ,he ranks below ,ari in value and below ,snorri in power2 but no one else can dispute his place in the first rank of ,icelandic writers4 ,of the ecclesiastical biographers1 an anonymous ,skalholt clerk is the best4 ,he wrote ,hungrvaka1 lives of the first five bishops of ,skalholt1 and biographies of his patron ,bishop ,paul 7,plssaga7 and also of ,st ,thorlak 7,thorlakssaga74 ,they are full of interesting notices of social and church life4 ,thorlak was a learned man1 and had studied at ,paris and ,lincoln1 which he left in #aafa4 ,these lives cover the years #ajef-aaic4 ,the life of ,st ,john1 a great reformer1 a contemporary of ,thorodd1 whom he employed to build a church for him1 is by another author 7#ajeb-aaba74 ,the life of ,gudmund 7,gudmundar ,saga ,goda71 as priest1 recounts the early life of this ,icelandic ,becket till his election as bishop 7#aafj-abjb72 his after career must be sought out in ,islendinga4 ,it is written by a friend and contemporary4 ,a later life by ,arngrim1 abbot of ,thingore1 written c4 #acej1 as evidence of his subject's sanctity1 tells a good deal about ,icelandic life1 c4 ,the lives of ,bishops ,arni and ,lawrence bring down our knowledge of ,icelandic history into the #adth century4 ,the former work1 ,arna ,saga ,biskups1 is imperfect2 it is the record of the struggles of church and state over patronage rights and glebes1 written c4 #acae2 it now covers only the years #abfi-abia2 a great many documents are given in it1 after the modern fashion4 ,the latter1 ,laurentius ,saga ,biskups1 by his disciple1 priest ,einar ,haflidason1 is a charming biography of a good and pious man1 whose chequered career in ,norway and ,iceland is picturesquely told 7#acbd-acca74 ,it is the last of the sagas4 ,bishop ,jon's ,table-,talk 7#acbe-acci7 is also worth noticing2 it contains many popular stories which the good bishop1 who had studied at ,bologna and ,paris1 was wont to tell to his friends4 ,annals4--,the ,annals are now almost the sole material for ,icelandic history2 they had begun earlier1 but after #acca they got fuller and richer1 till they end in #adcj4 ,the best are ,annales ,regii1 ending #acjf1 ,einar ,haflidason's ,annals1 known as ,lawman's ,annals1 reaching to #acib1 and preserved with others in ,flatey-book1 and the ,new ,annals1 last of all4 ,the ,diplomatarium ,islandicum1 edited by ,jon ,sigurdsson1 contains what remains of deeds1 inventories1 letters1 c41 from the old days1 completing our scanty material for this dark period of the island's history4 ,literature of ,foreign ,origin4--,after the union with ,norway and change of law genuine tradition died out with the great houses4 ,the ordinary medieval literature reached ,iceland through ,norway1 and every one began to put it into a vernacular dress1 so neglecting their own classics that but for a few collectors like ,lawman ,hauk they would have perished entirely4 ,the ,norwegian kings1 ,haakon ,haakonson 7c4 #abbe71 and ,haakon ,v4 7c4 #acje71 employed ,icelanders at their courts in translating the ,french romances of the ,alexander1 ,arthur and ,charlemagne cycles4 ,some forty or fifty of these ,riddara-,sgur 7,romances of ,chivalry7 remain4 ,they reached ,iceland and were eagerly read1 many ,rimur being founded on them4 ,norse versions of ,mary of ,brittany's ,lays1 the stories of ,brutus and of ,troy1 and part of the ,pharsalia translated are also found4 ,the ,speculum ,regale1 with its interesting geographical and social information1 is also ,norse1 written c4 #abdj1 by a ,halogalander4 ,the computistic and arithmetical treatises of ,stiorn-,odd1 ,biarni the ,number-skilled 7d4 #aagc71 and ,hauk ,erlendsson the ,lawman 7d4 #accd71 and the geography of ,ivar ,bardsson1 a ,norwegian 7c4 #acdj71 are of course of foreign origin4 ,a few tracts on geography1 c41 in ,hauk's book1 and a ,guide to the ,holy ,land1 by ,nicholas1 abbot of ,thwera 7d4 #aaeh71 complete the list of scientific works4 ,the stories which contain the last lees of the old mythology and pre-history seem to be also non-,icelandic1 but amplified by ,icelandic editors1 who probably got the plots from the ,western ,islands4 ,vlsunga ,saga and ,hervarar ,saga contain quotations and paraphrases of lays by the ,helgi poet1 and ,half's1 ,ragnar's and ,asmund ,kappabana's ,sagas all have bits of ,western poetry in them4 ,hrolf ,kraki's ,saga paraphrases part of ,biarkamal2 ,hromund ,gripsson's gives the story of ,helgi and ,kara 7the lost third of the ,helgi trilogy72 ,gautrek's ,arrow ,odd's1 ,frithiof's ,sagas1 c41 contain shreds of true tradition amidst a mass of later fictitious matter of no worth4 ,with the ,riddara-,sgur they enjoyed great popularity in the #aeth century1 and gave matter for many ,rimur4 ,thidrek's ,saga1 a late version of the ,vlsung story1 is of ,norse composition 7c4 #abcj71 from ,north ,german sources4 ,the medieval religious literature of ,western ,europe also influenced ,iceland1 and the ,homilies 7like the ,laws7 were1 according to ,thorodd1 the earliest books written in the vernacular1 antedating even ,ari's histories4 ,the lives of the ,virgin1 the ,apostles and the ,saints fill many ,,mss4 7edited in four large volumes by ,professor ,unger71 and are the works of many authors1 chiefly of the #acth and #adth centuries2 amongst them are the lives of ,,ss4 ,edward the ,confessor1 ,oswald of ,northumbria1 ,dunstan and ,thomas of ,canterbury4 ,of the authors we know ,priest ,berg ,gunsteinsson 7d4 #abaa72 ,kygri-,biorn1 bishop-elect 7d4 #abcg72 ,bishop ,brand 7d4 #abfd72 ,abbot ,runolf 7d4 #acjg72 ,bishop ,lawrence's son ,arni 7c4 #accj72 ,abbot ,berg 7c4 #acdj71 c4 ,a paraphrase of the historical books of the ,bible was made by ,bishop ,brand 7d4 #abfd71 called ,gydinga ,sgur4 ,about #acaj ,king ,haakon ,v4 ordered a commentary on the ,bible to be made1 which was completed down to ,exodus xix4 ,to this ,brand's work was afterwards affixed1 and the whole is known as ,stiorn4 ,the ,norse version of the famous ,barlaam and ,josaphat1 made for ,prince ,haakon 7c4 #abdj71 must not be forgotten4 ,post-classical ,literature4--,the post-classical literature falls chiefly under three heads--religious1 literary and scientific4 ,under the first comes foremost the noble translation of the ,new ,testament by ,odd ,gottskalksson1 son of the bishop of ,hlar4 ,brought up in ,norway1 he travelled in ,denmark and ,germany1 and took upon him the new faith before he returned to ,iceland1 where he became secretary to ,bishop ,ogmund of ,skalholt4 ,here he began by translating the ,gospel of ,matthew into his mother-tongue in secret4 ,having finished the remainder of the ,new ,testament at his own house at ,olves1 he took it to ,denmark1 where it was printed at ,roskild in #aedj4 ,odd afterwards translated the ,psalms1 and several devotional works of the day1 ,corvinus's ,epistles1 c4 ,he was made lawman of the north and west1 and died from a fall in the ,laxa in ,kios1 ,june #aeef4 ,three years after his death the first press was set up in ,iceland by ,john ,matthewson1 at ,breidabolstad1 in ,hunafloe1 and a ,gospel and ,epistle ,book1 according to ,odd's version1 issued from it in #aefb4 ,in #aehd ,bishop ,gudbrand1 who had brought over a splendid fount of type from ,denmark in #aege 7which he completed with his own hands71 printed a translation of the whole ,bible at ,hlar1 incorporating ,odd's versions and some books 7,proverbs and the ,son of ,sirach1 #aehj7 translated by ,bishop ,gizar1 but supplying most of the ,old ,testament himself4 ,this fine volume was the basis of every ,bible issued for ,iceland till #ahbf1 when it was replaced by a bad modern version4 ,for beauty of language and faithful simplicity of style the finer parts of this version1 especially the ,new ,testament1 have never been surpassed4 ,the most notable theological work ,iceland ever produced is the ,postill-,book of ,bishop ,john ,vidalin 7#afff-agbj71 whose bold homely style and stirring eloquence made ,john's ,book1 as it is lovingly called1 a favourite in every household1 till in the #aith century it was replaced for the worse by the more sentimental and polished ,danish tracts and sermons4 ,theological literature is very popular1 and many works on this subject1 chiefly translations1 will be found in the lists of ,icelandic bibliographers4 ,the first modern scientific work is the ,iter per patriam of ,eggert ,olafsson and ,biarni ,paulsson1 which gives an account of the physical peculiarities--fauna1 flora1 c4--of the island as far as could be done at the date of its appearance1 #aggb4 ,the island was first made known to the world by this book and by the sketch of ,unno von ,troil1 a ,swede1 who accompanied ,sir ,joseph ,banks to ,iceland in #aggb1 and afterwards wrote a series of letters on the land and its literature1 c4 ,this tour was the forerunner of an endless series of travels1 of which those of ,sir ,w4 ,j4 ,hooker1 ,sir ,g4 ,s4 ,mackenzie 7#ahaj71 ,ebenezer ,henderson 7#ahah71 ,joseph ,paul ,gaimard 7#ahch-ahdc71 ,paijkull 7#ahfg7 and1 lastly1 that of ,sir ,richard ,burton1 an excellent account of the land and people1 crammed with information of every kind 7#ahge71 are the best4 ,iceland is emphatically a land of proverbs1 while of folk-tales1 those other keys to the people's heart1 there is plentiful store4 ,early work in this direction was done by ,jon ,gudmundsson1 ,olaf the ,old and ,john ,olafsson in the #agth century1 who all put traditions on paper1 and their labours were completed by the magnificent collection of ,jon ,arnason 7#ahfb-ahfd71 who was inspired by the example of the ,grimms4 ,many tales are but weak echoes of the sagas2 many were family legends1 many are old fairy tales in a garb suited to their new northern home2 but1 besides all these1 there are a number of traditions and superstitions of indigenous origin4 ,the ,renaissance of ,iceland dates from the beginning of the #agth century1 when a school of antiquaries arose4 ,arngrim ,jonsson's ,brevis ,commentarius 7#aeic71 and ,crymogaea 7#afji71 were the first-fruits of this movement1 of which ,bishops ,odd1 ,thorlak and ,bryniulf 7worthy parallels to ,parker and ,laud7 were the wise and earnest supporters4 ,the first 7d4 #afcj7 collected much material for church history4 ,the second 7d4 #afef7 saved ,sturlunga and the ,bishops' ,lives1 encouraged ,john ,egilsson to write his ,new ,hungerwaker1 lives of the bishops of the ,dark ,ages and ,reformation1 and helped ,biorn of ,skardsa 7d4 #afee71 a bold and patriotic antiquary 7whose ,annals continue ,einar's71 in his researches4 ,the last 7d4 #afge7 collected a fine library of ,,mss41 and employed the famous copyist ,john ,erlendsson1 to whom and the bishop's brother1 ,john ,gizurarsson 7d4 #afdh71 we are indebted for transcripts of many lost ,,mss4 ,torfaeus 7#afcf-agai7 and ,bartholin1 a ,dane 7d4 #afij71 roused the taste for northern literature in ,europe1 a taste which has never since flagged2 and soon after them ,arni ,magnusson 7#affc-agcj7 transferred all that remained of vellum and good paper ,,mss4 in ,iceland to ,denmark1 and laid the foundations of the famous library and bequest1 for which all ,icelandic students are so much beholden4 ,for over forty years ,arni stuck to his task1 rescuing every scrap he could lay hands on from the risks of the ,icelandic climate and carelessness1 and when he died only one good ,,mss4 remained in the island4 ,besides his magnificent collection1 there are a few ,,mss4 of great value at ,upsala1 at ,stockholm1 and in the old royal collection at ,copenhagen4 ,those in the university library in the latter city perished in the fire of #agbh4 ,sagas were printed at ,upsala and ,copenhagen in the #agth century1 and the ,arna-,magnaean fund has been working since #aggb4 ,in that year appeared also the first volume of ,bishop ,finn ,jonsson's ,historia ,ecclesiastica ,islandiae1 a work of high value and much erudition1 containing not only ecclesiastical but civil and literary history1 illustrated by a well-chosen mass of documents1 #hgj-agdj4 ,it has been continued by ,bishop ,p4 ,peterson to modern times1 #agdj-ahdj4 ,the results1 however1 of modern observers and scholars must be sought for in the periodicals1 ,safn1 ,felagsrit1 ,ny ,felagsrit and others4 ,john ,espolin's ,arbkr is very good up to its date1 #ahba4 ,a brilliant sketch of ,icelandic classic literature is given by ,dr ,gudbrandr ,vigfusson in the ,prolegomena to ,sturlunga ,saga 7,oxford1 #ahgi74 ,it replaces much earlier work1 especially the ,sciagraphia of ,halfdan ,einarsson 7#aggg71 and the ,saga-,bibliotek of ,mller4 ,the numerous editions of the classics by the ,icelandic societies1 the ,danish ,socit des ,antiquits1 ,nordiske ,litteratur ,samfund1 and the new ,gammel ,nordisk ,litteratur ,samfund1 the splendid ,norwegian editions of ,unger1 the labours of the ,icelanders ,sigurdsson and ,gislason1 and of those foreign scholars in ,scandinavia and ,germany who have thrown themselves into the work of illustrating1 publishing and editing the sagas and poems 7men like ,p4 ,a4 ,munch1 ,s4 ,bugge1 ,f4 ,w4 ,bergmann1 ,th4 ,mbius and ,k4 von ,maurer1 to name only a few71 can only be referred to here4 ,see also ,finnur ,jnsson1 ,den ,oldnorske og ,oldislanske ,litteraturs ,historie 7,copenhagen1 #ahic-aijj72 ,r4 ,b4 ,anderson's translation 7,chicago1 #ahhd7 of ,winkel ,horn's ,history of the ,literature of the ,scandinavian ,north2 and ,w4 ,morris and ,e4 ,magnusson's ,saga ,library4 7,f4 ,y4 ,p47 ,,recent ,,literature ,the recent literature of ,iceland has been in a more flourishing state than ever before since the #acth century4 ,lyrical poetry is by far the largest and the most interesting portion of it4 ,the great influence of ,jnas ,hallgrmsson 7#ahjg-ahde7 is still felt1 and his school was the reigning one up to the end of the #aith century1 although then a change seemed to be in sight4 ,the most successful poet of this school is ,steingrmr ,thorsteinsson 7b4 #ahcj74 ,he is specially famous for his splendid descriptions of scenery 7,the ,song of ,gilsbakki71 his love-songs and his sarcastic epigrams4 ,as a translator he has enriched the literature with ,the ,arabian ,nights1 ,sakuntala1 ,king ,lear and several other masterpieces of foreign literature4 ,equal in fame is ,matthas ,jochumsson 7b4 #ahce71 who1 following another of ,jnas ,hallgrmsson's many ways1 has successfully revived the old metres of the classical ,icelandic poets1 whom he resembles in his majestic1 but sometimes too gorgeous1 language4 ,he is as an artist inferior to ,steingrmr ,thorsteinsson1 but surpasses him in bold flight of imagination4 ,he has successfully treated subjects from ,icelandic history ,grettislj1 a series of poems about the famous outlaw ,grettir4 ,his chief fault is a certain carelessness in writing2 he can never write a bad poem1 but rarely a poem absolutely flawless4 ,he has translated ,tegnr's ,frithiofs ,saga1 several plays of ,shakespeare and some other foreign masterpieces4 ,the great religious poet of ,iceland1 ,hallgrmr ,ptursson1 has found a worthy successor in ,valdemar ,briem 7b4 #ahdh71 whose ,songs of the ,bible are deservedly popular4 ,he is like ,matthas ,jochumsson in the copious flow of his rhetoric2 some of his poems are perfect both as regards form and contents1 but he sometimes neglects the latter while polishing the former4 ,an interesting position is occupied by ,benedict ,grndal 7b4 #ahbf71 whose travesties of the old romantic stories1#g and his ,aristophanic drama ,gandreiin 7,the ,magic ,ride7 about contemporary events1 are among the best satirical and humorous productions of ,icelandic literature4 ,influenced by ,jnas ,hallgrmsson with regard to language and poetic diction1 but keeping unbroken the traditions of ,icelandic medieval poetry maintained by ,sigurr ,breifjr 7#agih-ahdf71 is another school of poets1 very unlike the first4 ,in the middle of the #aith century this school was best represented by ,hjlmar ,jnsson from ,bla 7#agif-ahge71 a poor farmer with little education1 but endowed with great poetical talents1 and the author of satirical verses not inferior to those of ,juvenal both in force and coarseness4 ,in the last decades of the #aith century this school produced two poets of a very high order1 both distinctly original and ,icelandic4 ,one is ,pll ,olafsson 7b4 #ahbg74 ,his songs are mostly written in the medieval quatrains 7ferskeytla71 and are generally of a humorous and satirical character2 his convivial songs are known by heart by every modern ,icelander2 and although some of the poets of the present day are more admired1 there is none who is more loved by the people4 ,the other is orsteinn ,erlingsson 7b4 #aheh74 ,his exquisite satirical songs1 in an easy and elegant but still manly and splendid language1 have raised much discussion4 ,of his poems may be mentioned ,the ,oath1 a series of most beautiful ballads1 with a tragical love-story of the #agth century as their base1 but with many and happy satirical allusions to modern life2 ,jrundr1 a long poem about the convict king1 the ,danish pirate ,jrgensen1 who nearly succeeded in making himself the master of ,iceland1 and ,the ,fate of the ,gods and ,the ,men of the ,west 7the ,americans71 two poems which1 with their anti-clerical and half-socialistic tendencies1 have caused strong protests from orthodox ,lutheran clergy4 ,near to this school1 but still standing apart1 is ,grmur ,thomsen 7b4 #ahbj74 ,in the beginning of the 'eighties a new school arose--having its origin in the colony of ,icelandic students at the ,university of ,copenhagen4 ,they had all attended the lectures of ,georg ,brandes1 the great reformer of ,scandinavian literature1 and1 influenced by his literary theories1 they chose their models in the realistic school4 ,this school is very dissimilar from the half-romantic school of ,jnas ,hallgrmsson2 it is nearer the national ,icelandic school represented by ,pll ,olafsson and orsteinn ,erlingsson1 but differs from those writers by introducing foreign elements hitherto unknown in ,icelandic literature1 and--especially in the case of the prose-writers--by imitating closely the style and manner of some of the great ,norwegian novelists4 ,their influence brought the ,icelandic literature into new roads1 and it is interesting to see how the tough ,icelandic element gradually assimilates the foreign4 ,of the lyrical poets1 ,hannes ,hafsteinn 7b4 #ahfa7 is by far the most important4 ,in his splendid ballad1 ,the ,death of ,skarphedinn1 and in his beautiful series of songs describing a voyage through some of the most picturesque parts of ,iceland1 he is entirely original2 but in his love-songs1 beautiful as many of them are1 a strong foreign influence can be observed4 ,among the innovations of this poet we may note a predilection for new metres1 sometimes adopted from foreign languages1 sometimes invented by himself1 a thing practised rarely and generally with small success by the ,icelandic poets4 ,no ,icelandic novelist has as yet equalled ,jn ,throddsen 7#ahai-ahfh74 ,the influence of the realistic school has of late been predominant4 ,the most distinguished writer of that school has been ,gestur ,plsson 7#aheb-ahia71 whose short stories with their sharp and biting satire have produced many imitations in ,iceland4 ,the best are ,a ,home of ,love and ,captain ,sigurd4 ,jnas ,jnasson 7b4 #ahef71 a clergyman of northern ,iceland1 has1 in a series of novels and short stories1 given accurate1 but somewhat dry1 descriptions of the more gloomy sides of ,icelandic country life4 ,his best novel is ,randir from ,hvassafell1 an historical novel of the middle ages4 ,besides these we may mention ,torfhildur ,hlm1 one of the few women who have distinguished themselves in ,icelandic literature4 ,her novels are mostly historical4 ,the last decade of the #aith century saw the establishment of a permanent theatre at ,reykjavik4 ,the poet ,matthas ,jochumsson has written several dramas1 but their chief merits are lyrical4 ,the most successful of ,icelandic dramatists as yet is ,indri ,einarsson1 whose plays1 chiefly historical1 in spite of excessive rhetoric1 are very interesting and possess a true dramatic spirit4 ,in geography and geology orvaldr ,thoroddsen has acquired a ,european fame for his researches and travels in ,iceland1 especially in the rarely-visited interior4 ,of his numerous writings in ,icelandic1 ,danish and ,german1 the ,history of ,icelandic ,geography is a monumental work4 ,in history ,pll ,melste's 7b4 #ahab7 chief work1 the large ,history of the ,world1 belongs to this period1 and its pure style has had a beneficial influence upon modern ,icelandic prose4 ,of the younger historians we may mention orkell ,bjarnason 7,history of the ,reformation in ,iceland74 ,jn orkelsson 7b4 #ahbb71 inspector of the archives of ,iceland1 has rendered great services to the study of ,icelandic history and literature by his editions of the ,diplomatarium ,islandicum and ,obituarium ,islandicum1 and by his ,icelandic ,poetry in the #aeth and #afth ,century1 written in ,danish1 an indispensable work for any student of that period4 ,a leading position among ,icelandic lexicographers is occupied by ,jn orkelsson1 formerly head of the ,latin school at ,reykjavik1 whose ,supplement til islandske ,ordbger1 an ,icelandic-,danish vocabulary 7three separate collections71 has hardly been equalled in learning and accuracy4 ,other distinguished philologists are his successor as head of the ,latin school1 ,bjrn ,magnsson ,olsen 7,researches on ,sturlunga1 ,ari the ,wise1 ,the ,runes in the ,old ,icelandic ,literature--the last two works in ,danish72 ,finnur ,jnsson1 professor at the ,university of ,copenhagen 7,history of the ,old ,norwegian and ,icelandic ,literature1 in ,danish1 and excellent editions of many old ,icelandic classical works72 and ,valtr ,gumundsson1 lecturer at the ,university of ,copenhagen 7several works on the old architecture of ,scandinavia7 and editor of the influential ,icelandic literary and political review1 ,eimreiin 7,the ,locomotive74 ,see ,j4 ,c4 ,poestion1 ,islandische ,dichter der ,neuzeit 7,leipzig1 #ahig72 ,c4 ,kchler1 ,geschichte der islndischen ,dichtung der ,neuzeit 7,leipzig1 #ahif72 ,ph4 ,schweitzer1 ,island2 ,land und ,leute 7,leipzig1 #ahhe72 ,alexander ,baumgartner1 ,island und die ,faroer 7,freiburg im ,breisgau1 #ahhi74 7,s4 ,bl47 ,,footnotes3 #a ,jkull1 plural jklar1 ,icel4 snowfield1 glacier4 #b ,fli1 bay2 fjrr1 fjord4 #c ,vatn1 lake4 #d ,see ,th4 ,thoroddsen1 ,explorations in ,iceland during the years #ahha-ahih1 ,geographical ,journal1 vol4 xiii4 7#ahii71 pp4 #bea-bgd1 #dhj-eac1 with map4 #e ,for the periods succeeding the union1 ,danish state papers and the ,history of ,finn ,jonsson are the best authority4 #f ,many of these poems were ,englished in prose by the translator of ,mallet1 by ,b4 ,thorpe in his ,smund's ,edda1 and two or three by ,messrs ,morris and ,magnussen1 as appendices to their translation of ,volsunga ,saga4 ,earlier translations in verse are those in ,dryden's ,miscellany 7vol4 vi71 ,a4 ,cottle's ,edda1 ,mathias's ,translations1 and ,w4 ,herbert's ,old ,icelandic ,poetry4 ,gray's versions of ,darradar-liod and ,vegtamskvia are well known4 #g ,e4g4 ,the ,battle of the ,plains of ,death1 a burlesque on the battle of ,solferino4 ,,iceland ,,moss1 a lichen 7,cetraria islandica7 whose erect or ascending foliaceous habit gives it something of the appearance of a moss1 whence probably the name4 ,it is often of a pale chestnut colour1 but varies considerably1 being sometimes almost entirely greyish white2 and grows to a height of from #c to #d in41 the branches being channelled or rolled into tubes1 which terminate in flattened lobes with fringed edges4 ,it grows abundantly in the mountainous regions of northern countries1 and it is specially characteristic of the lava slopes and plains of the west and north of ,iceland4 ,it is found on the mountains of north ,wales1 north ,england1 ,scotland and south-west ,ireland4 ,as met with in commerce it is a light-grey harsh cartilaginous body1 almost destitute of colour1 and having a slightly bitter taste4 ,it contains about #gj of lichenin or lichen-starch1 a body isomeric with common starch1 but wanting any appearance of structure4 ,it also yields a peculiar modification of chlorophyll1 called thallochlor1 fumaric acid1 licheno-stearic acid and cetraric acid1 to which last it owes its bitter taste4 ,it forms a nutritious and easily digested amylaceous food1 being used in place of starch in some preparations of cocoa4 ,it is not1 however1 in great request1 and even in ,iceland it is only habitually resorted to in seasons of scarcity4 ,cetraric acid or cetrarin1 a white micro-crystalline powder with a bitter taste1 is readily soluble in alcohol1 and slightly soluble in water and ether4 ,it has been recommended for medicinal use1 in doses of #b to #d grains1 as a bitter tonic and aperient4 ,,ice-,,plant1 the popular name for ,mesembryanthemum crystallinum1 a hardy annual most effective for rockwork4 ,it is a low-growing spreading herbaceous plant with the fleshy stem and leaves covered with large glittering papillae which give it the appearance of being coated with ice4 ,it is a dry-country plant1 a native of ,greece and other parts of the ,mediterranean region1 the ,canary ,islands1 ,south ,africa and ,california4 ,mesembryanthemum is a large genus 7containing about #cjj species7 of erect or prostrate fleshy herbs or low shrubs1 mostly natives of ,south ,africa1 and rarely hardy in the ,british ,isles where they are mostly grown as greenhouse plants4 ,they bear conspicuous white1 yellow or red flowers with many petals inserted in the calyx-tube4 ,the thick fleshy leaves are very variable in shape1 and often have spiny rigid hairs on the margin4 ,they are essentially sun-loving plants4 ,the best-known member of the genus is ,m4 cordifolium1 var4 variegatum1 with heart-shaped green and silvery leaves and bright rosy-purple flowers4 ,it is extensively used for edging flower-beds and borders during the summer months4 ,,ice-,,yachting1 the sport of sailing and racing ice-boats4 ,it is practised in ,great ,britain1 ,norway and ,sweden1 to some extent1 and is very popular in ,holland and on the ,gulf of ,finland1 but its highest development is in the ,united ,states and ,canada4 ,the ,dutch ice-yacht is a flat-bottomed boat resting crossways upon a planking about three feet wide and sixteen long1 to which are affixed four steel runners1 one each at bow1 stern and each end of the planking4 ,the rudder is a fifth runner fixed to a tiller4 ,heavy mainsails and jibs are generally used and the boat is built more for safety than for speed4 ,the ice-boat of the ,gulf of ,finland is a ,v-shaped frame with a heavy plank running from bow to stern1 in which the mast is stepped4 ,the stern or steering runner is worked by a tiller or wheel4 ,the sail is a large lug and the boom and gaff are attached to the mast by travellers4 ,the passengers sit upon planks or rope netting4 ,the ,russian boats are faster than the ,dutch4 ,in #agij ice-yachting was in vogue on the ,hudson river1 its headquarters being at ,poughkeepsie1 ,new ,york4 ,the type was a square box on three runners1 the two forward ones being nailed to the box and the third acting as a rudder operated by a tiller4 ,the sail was a flatheaded sprit4 ,this primitive style generally obtained until #ahec1 when triangular frames with boxes for the crew aft and jib and mainsail rig were introduced4 ,a heavy1 hard-riding type soon developed1 with short gaffs1 low sails1 large jibs and booms extending far over the stern4 ,it was over-canvassed and the mast was stepped directly over the runner-plank1 bringing the centre of sail-balance so far aft that the boats were apt to run away1 and the over-canvassing frequently caused the windward runner to swing up into the air to a dangerous height4 ,the largest and fastest example of this type1 which prevailed until #ahgi1 was ,commodore ,j4 ,a4 ,roosevelt's first ,icicle1 which measured #fi ft4 over all and carried #ajgj sq4 ft4 of canvas4 ,in #ahgi ,mr ,h4 ,relyea built the ,robert ,scott1 which had a single backbone and wire guy-ropes1 and it became the model for all ,hudson river ice-yachts4 ,masts were now stepped farther forward1 jibs were shortened1 booms cut down1 and the centre of sail-balance was brought more inboard and higher up1 causing the centres of effort and resistance to come more in harmony4 ,the shallow steering-box became elliptical4 ,in #ahha occurred the first race for the ,american ,challenge ,pennant1 which represents the championship of the ,hudson river1 the clubs competing including the ,hudson river1 ,north ,shrewsbury1 ,orange lake1 ,newburgh and ,carthage ,ice-,yacht ,clubs4 ,the races are usually sailed five times round a triangle of which each leg measures one mile1 at least two of the legs being to windward4 ,ice-yachts are divided into four classes1 carrying respectively #fjj sq4 ft4 of canvas or more1 between #dej and #fjj1 between #cjj and #dej1 and less than #cjj sq4 ft4 ,ice-yachting is very popular on the ,great ,lakes1 both in the ,united ,states and ,canada1 the ,kingston 7,ontario7 ,club having a fleet of over #be sail4 ,other important centres of the sport are ,lakes ,minnetonka and ,white ,bear in ,minnesota1 ,lakes ,winnebago and ,pepin in ,wisconsin1 ,bar ,harbor lake in ,maine1 the ,st ,lawrence river1 ,quinte ,bay and ,lake ,champlain4 ,a modern ice-yacht is made of a single-piece backbone the entire length of the boat1 and a runner-plank upon which it rests at right angles1 the two forming a kite-shaped frame4 ,the best woods for these pieces are basswood1 butternut and pine4 ,they are cut from the log in such a way that the heart of the timber expands1 giving the planks a permanent curve1 which1 in the finished boat1 is turned upward4 ,the two forward runners1 usually made of soft cast iron and about #b ft4 #g in4 long and #b in4 high1 are set into oak frames a little over #e ft4 long and #e in4 high4 ,the runners have a cutting edge of #ij1 though a ,v-shaped edge is often preferred for racing4 ,the rudder is a runner about #c ft4 #g in4 long1 worked by a tiller1 sometimes made very long1 #g ft4 not being uncommon4 ,this enables the helmsman to lie in the box at full length and steer with his feet1 leaving his hands free to tend the sheet4 ,masts and spars are generally made hollow for racing-yachts and the rigging is pliable steel wire4 ,the sails are of #aj-oz4 duck for a boat carrying #djj sq4 ft4 of canvas4 ,they have very high peaks1 short hoists and long booms4 ,the mainsail and jib rig is general1 but a double-masted lateen rig has been found advantageous4 ,the foremost ice-yacht builder of ,america is ,g4 ,e4 ,buckhout of ,poughkeepsie4 ,an ice-yacht about #dj ft4 in length will carry #f or #g passengers or crew1 who are distributed in such a manner as to preserve the balance of the boat4 ,in a good breeze the crew lie out on the windward side of the runner-plank to balance the boat and reduce the pressure on the leeward runner4 ,a course of #bj m4 with many turns has been sailed on the ,hudson in less than #dh minutes1 the record for a measured mile with flying start being at the rate of about #gb m4 an hour4 ,in a high wind1 however1 ice-yachts often move at the rate of #he and even #ij m4 an hour4 ,several of the laws of ice navigation seem marvellous to the uninitiated4 ,commodore ,irving ,grinnell1 who has made a scientific study of the sport1 says3 ,the two marked peculiarities of ice-yachting which cause it to differ materially from yachting on the sea are3 7#a7 ,sailing faster than the wind4 7#b7 ,sheets flat aft under all circumstances4 ,mr ,h4 ,a4 ,buck1 in the ,badminton ,library1 ,skating1 ,curling1 ,tobogganing1 c41 thus explains these paradoxes4 ,an ice-boat sails faster than the wind because she invariably sails at some angle to it4 ,the momentum is increased by every puff of wind striking the sails obliquely1 until it is finally equalled by the increase of friction engendered4 ,thus the continued bursts of wind against the sails cause a greater accumulation of speed in the ice-yacht than is possessed by the wind itself4 ,when the boat sails directly before the wind she is1 like a balloon1 at its mercy1 and thus does not sail faster than the wind4 ,the ice-yacht always sails with its sheets flat aft1 because the greater speed of the boat changes the angle at which the wind strikes the sail from that at which it would strike if the yacht were stationary to such a degree that1 in whatever direction the yacht is sailing1 the result is always the same as if the yacht were close-hauled to the wind4 ,it follows that the yacht is actually overhauling the wind1 and her canvas shivers as if in the wind's eye4 ,when eased off her momentum becomes less and less until it drops to the velocity of the wind1 when she can readily be stopped by being spun round and brought head to the wind4 ,the latter method is one way of coming to1 instead of luffing up in the usual way from a beam wind4 ,in beating to windward an ice-boat is handled like a water yacht1 though she points more closely4 ,on the bays near ,new ,york a peculiar kind of ice-boat has developed1 called scooter1 which may be described as a toboggan with a sail4 ,a typical scooter is about #ae ft4 long with an extreme beam of #e ft41 perfectly oval in form and flat4 ,it has mainsail and jib carried on a mast #i or #aj ft4 long and set well aft1 and is provided with two long parallel metal runners4 ,there is no rudder1 the scooter being steered entirely by trimming the sails1 particularly the jib4 ,as the craft is flat and buoyant it sails well in water1 and can thus be used on very thin ice without danger4 ,a speed of #ej m4 an hour has been attained by a scooter 7see ,outing for ,march #aije74 ,see ,ice ,sports1 in the ,isthmian ,library2 ,skating1 ,curling1 ,tobogganing1 c4 in the ,badminton ,library4 ,i-,,ch',,ang 7,,yi-,,ch',,ang1 anciently known as ,yi-ling71 a town of ,china in the province of ,hu-peh1 one of the four ports opened to foreign trade by treaty in #ahgg4 ,it is situated in #cj #db ,n4 and 7approximately7 #aaa #bj ,e41 on the ,yangtsze-,kiang1 #ajjj m4 from ,shanghai4 ,built on the left bank of the river where it escapes from the ravines and gorges which for #cej m4 have imprisoned its channel1 ,i-ch'ang is exposed to considerable risk of floods2 in #ahgj the waters rose #bj ft4 in one day1 and the town had many of its houses and about half of its wall swept away4 ,the first ,english vessels to ascend the river as far as ,i-ch'ang were those of ,admiral ,sir ,james ,hope's expedition in #ahfa4 ,all cargo to or from ,szech'uen is here transhipped from steamer to junk1 or vice vers4 ,about #aj m4 above ,i-ch'ang the famed scenery of the ,yangtsze gorges begins4 ,through these the great river runs in a series of rapids1 which make navigation by vessels of any size extremely difficult4 ,a very large trade1 nevertheless1 is carried on by this route between ,chungk'ing and ,i-ch'ang4 ,as a local centre of distribution this port is of no great consequence1 the transhipment trade with ,szech'uen being almost its sole business4 ,the population is estimated at #ce1jjj4 ,the number of foreign residents is very small1 trade being carried on by ,chinese agents4 ,before the anti-opium campaign of #aijf 7see ,,china7 opium was much grown4 ,the trade of the port amounted in #ahii to #eca1bbi1 and in #aijd to #dbd1ddb1 the principal import being cotton yarn and the principal export opium4 ,,ichneumon 7,gr4 ,greek3 ichneumn1 from ,greek3 ichneuein1 to track out71 the common name of the ,north ,african representative of a number of small weasel-shaped mammals belonging to the carnivorous family ,viverridae2 the ,indian representatives of the group being known as mongooses4 ,a large number of species of the type genus are known1 and range over southern ,asia and all ,africa1 the typical ,herpestes ichneumon also occurring in the south of ,spain4 ,the latter is an inhabitant of ,egypt and the north of ,africa1 where it is known to foreign residents as ,pharaoh's rat4 ,it is covered with long harsh fur of a tawny-grey colour1 darker on the head and along the middle of the back1 its legs reddish and its feet and tail black4 ,it lives largely on rats and mice1 birds and reptiles1 and for this reason it is domesticated4 ,it is1 however1 fond of poultry and their eggs1 and its depredations among fowls detract from its merits as a vermin-killer4 ,during the inundations of the ,nile it is said to approach the habitations of man1 but at other seasons it keeps to the fields and to the banks of the river4 ,the ,indian mongoose 7,h4 mungo7 is considerably smaller than the ,egyptian animal1 with fur of a pale-grey colour1 the hairs being largely white-ringed1 while the cheeks and throat are more or less reddish4 ,like the former it is frequently domesticated4 ,it is especially serviceable in ,india as a serpent-killer1 destroying not only the eggs and young of these creatures1 but killing the most venomous adult snakes4 ,the fact that it survives those encounters has led to the belief that it either enjoys immunity from the effects of snake poison1 or that after being bitten it has recourse1 as the ,hindus maintain1 to the root of a plant as an antidote4 ,it has been found1 however1 that when actually bitten it falls a victim to the poison as rapidly as other mammals1 while there is no evidence of its seeking a vegetable antidote4 ,the truth seems to be that the mongoose1 by its exceeding agility and quickness of eye1 avoids the fangs of the snake while fixing its own teeth in the back of the reptile's neck4 ,moreover1 when excited1 the mongoose erects its long stiff hair1 and it must be very difficult for a snake to drive its fangs through this and the thick skin which all the members of the genus possess4 ,the mongoose never hesitates to attack a snake2 the moment he sees his enemy1 his whole nature1 writes a spectator of one of those fights1 appears to be changed4 ,his fur stands on end1 and he presents the incarnation of intense rage4 ,the snake invariably attempts to escape1 but1 finding it impossible to evade the rapid onslaught of the mongoose1 raises his crest and lashes out fiercely at his little persecutor1 who seems to delight in dodging out of the way just in time4 ,this goes on until the mongoose sees his opportunity1 when like lightning he rushes in and seizes the snake with his teeth by the back of the neck close to the head1 shaking him as a terrier does a rat4 ,these tactics are repeated until the snake is killed4 ,the mongoose is equally dexterous in killing rats and other four-footed vermin4 ,illustration3 ,egyptian ,ichneumon 7,herpestes ichneumon74 ,,ichneumon-,,fly1 a general name applied to parasitic insects of the section ,ichneumonoidea 7or ,entomophaga71 order ,hymenoptera1 from the typical genus ,ichneumon1 belonging to the chief family of that section--itself fancifully so called after the ,egyptian mammal 7,herpestes74 ,the species of the families 7,ichneumonidae1 ,braconidae1 ,evaniidae1 ,proctotrypidae1 and ,chalcididae7 are often indiscriminately called ,ichneumons1 but the super-family of the ,ichneumonoidea in the classification of ,w4 ,h4 ,ashmead contains only the ,evaniidae1 the ,stephanidae1 and the large assemblage of insects usually included in the two families of the ,ichneumonidae and the ,braconidae1 which are respectively equivalent to the ,ichneumones genuini and ,i4 adsciti of older naturalists1 chiefly differing in the former having two recurrent nerves to the anterior wing1 whilst the latter has only one such nerve4 ,the ,ichneumonidae proper are one of the most extensive groups of insects4 ,gravenhorst described some #afej ,european species1 to which considerable subsequent additions have been made4 ,there are #f sub-families of the ,ichneumonidae1 viz4 the ,ichneumoninae1 ,cryptinae1 ,agriotypinae1 ,ophioninae1 ,tryphoninae and ,pimplinae1 differing considerably in size and facies1 but united in the common attribute of being1 in their earlier stages1 parasitic upon other insects4 ,they have all long narrow bodies2 a small free head with long filiform or setaceous antennae1 which are never elbowed1 and have always more than sixteen joints2 the abdomen attached to the thorax at its hinder extremity between the base of the posterior coxae1 and provided in the female with a straight ovipositor often exserted and very long2 and the wings veined1 with perfect cells on the disk of the front pair4 ,ashmead proposes to separate the ,agriotypidae 7which are remarkable for their aquatic habit1 being parasitic on caddis-worms7 from the ,ichneumonidae on account of their firm ventral abdominal segments and spined scutellum4 ,he also separates from the ,braconidae the ,alysiidae as a distinct family2 they have peculiar mandibles with out-turned tips4 ,their parasitic habits render these flies of great importance in the economy of nature1 as they serve to check any inordinate increase in the numbers of injurious insects4 ,without their aid it would in many cases be impossible for the agriculturist to hold his own against the ravages of his minute insect foes1 whose habits are not sufficiently known to render artificial checks or destroying agents available4 ,the females of all the species are constantly on the alert to discover the proper living food for their own larvae1 which are hatched from the eggs they deposit in or on the eggs1 larvae or pupae of other insects of all orders1 chiefly ,lepidoptera1 the caterpillars of butterflies and moths being specially attacked 7as also are spiders74 ,any one who has watched insect life during the summer can hardly have failed to notice the busy way in which the parent ichneumon1 a small four-winged fly1 with constantly vibrating antennae1 searches for her prey2 and the clusters of minute cocoons round the remains of some cabbage-butterfly caterpillar must also have been observed by many4 ,this is the work of ,apanteles 7or ,microgaster7 glomeratus1 one of the ,braconidae1 which in days past was a source of disquietude to naturalists1 who believed that the life of the one defunct larva had transmigrated into the numerous smaller flies reared from it4 ,ichneumon-flies which attack external feeders have a short ovipositor1 but those attached to wood-feeding insects have that organ of great length1 for the purpose of reaching the haunts of their concealed prey4 ,thus a species from ,japan 7,bracon penetrator7 has its ovipositor nine times the length of the body2 and the large species of ,rhyssa and ,ephialtes1 parasitic on ,sirex and large wood-boring beetles in temperate ,europe1 have very long instruments 7with which when handled they will endeavour to sting1 sometimes penetrating the skin71 in order to get at their secreted victims4 ,a common reddish-coloured species of ,ophion 7,o4 obscurum71 with a sabre-shaped abdomen1 is noteworthy from the fact of its eggs being attached by stalks outside the body of the caterpillar of the puss-moth 7,cerura vinula74 ,lepidopterists wishing to breed the latter cut off the eggs of the parasite with scissors4 ,the larvae of the ichneumon-flies are white1 fleshy1 cylindrical1 footless grubs2 the majority of them spin silk cocoons before pupating1 often in a mass 7sometimes almost geometrically71 and sometimes in layers of different colours and texture4 ,,authorities4--,among the older works on ,ichneumonoidea may be specially mentioned ,j4 ,l4 ,k4 ,gravenhorst1 ,ichneumonologia ,europaea 7,breslau1 #ahbi72 ,a4 ,h4 ,haliday 7,entom4 ,mag4 i4-v41 #ahcc-ahch71 and ,a4 ,frster 7,verhandl4 ,naturhist4 ,ver4 ,rheinl4 u4 ,westph4 xix41 xxv41 #ahfb1 #ahfh74 ,full reference to the systematic literature of the group will be found in ,c4 ,g4 de ,dalla ,torre's ,catalogus hymenopterorum1 vols1 iii41 iv4 7,leipzig1 #ahih-aijb71 and a comprehensive summary in ,w4 ,h4 ,ashmead's recent memoir 7,proc4 ,u4,s4 ,nat4 ,mus4 xxiii41 #aija74 ,for the ,british species consult ,c4 ,morley1 ,ichneumons of ,great ,britain 7,plymouth1 #aijc71 and ,t4 ,a4 ,marshall 7,trans4 ,entom4 ,soc41 #ahhe-ahii74 7,g4 ,h4 ,c47 ,,ichnography 7,gr4 ,greek3 ichnos1 a trace1 and ,greek3 graph1 description71 in architecture1 a term defined by ,vitruvius 7i4#b7 as the ground-plan of the work1 i4e4 the geometrical projection or horizontal section representing the plan of any building1 taken at such a level as to show the outer walls1 with the doorways1 windows1 fireplaces1 c41 and the correct thickness of the walls2 the position of piers1 columns or pilasters1 courtyards and other features which constitute the design4