,,yale ,,university ,,mrs4 ,,hepsa ,,ely ,,silliman ,,memorial ,,lectures ,in the year #ahhc a legacy of eighty thousand dollars was left to the ,president and ,fellows of ,yale ,college in the city of ,new ,haven1 to be held in trust1 as a gift from her children1 in memory of their beloved and honored mother1 ,mrs4 ,hepsa ,ely ,silliman4 ,on this foundation ,yale ,college was requested and directed to establish an annual course of lectures designed to illustrate the presence and providence1 the wisdom and goodness of ,god1 as manifested in the natural and moral world4 ,these were to be designated as the ,mrs4 ,hepsa ,ely ,silliman ,memorial ,lectures4 ,it was the belief of the testator that any orderly presentation of the facts of nature or history contributed to the end of this foundation more effectively than any attempt to emphasize the elements of doctrine or of creed2 and he therefore provided that lectures on dogmatic or polemical theology should be excluded from the scope of this foundation1 and that the subjects should be selected rather from the domains of natural science and history1 giving special prominence to astronomy1 chemistry1 geology1 and anatomy4 ,it was further directed that each annual course should be made the basis of a volume to form part of a series constituting a memorial to ,mrs4 ,silliman4 ,the memorial fund came into the possession of the ,corporation of ,yale ,university in the year #aija2 and the present volume constitutes the fourteenth of the series of memorial lectures4 ,,silliman ,,memorial ,,lectures ,,published ,,by ,,yale ,,university ,,press ,,electricity ,,and ,,matter4 ,by ,,joseph ,,john ,,thomson1 ,d4,s4,c41 ,l4,l4,d1 ,,ph4,d41 ,f4,r4,s41 ,fellow of ,trinity ,college and ,cavendish ,professor of ,experimental ,physics1 ,cambridge ,university4 7,fourth printing47 ,price #a4ej net4 ,,the ,,integrative ,,action ,,of ,,the ,,nervous ,,system4 ,by ,,charles ,s4 ,,sherrington1 ,d4,,sc41 ,m4,d41 ,,hon4 ,,ll4,d4 ,,tor41 ,f4,r4,s41 ,holt ,professor of ,physiology1 ,university of ,liverpool4 7,fifth ,printing47 ,price #e4jj net4 ,,radioactive ,,transformations4 ,by ,,ernest ,,rutherford1 ,d4,,sc1 ,,ll4,d41 ,f4,r4,s41 ,macdonald ,professor of ,physics1 ,mc,gill ,university4 ,price #e4jj net4 ,,experimental ,,and ,,theoretical ,,applications ,,of ,,thermodynamics ,,to ,,chemistry4 ,by ,,dr4 ,,walter ,,nernst1 ,professor and ,director of the ,institute of ,physical ,chemistry in the ,university of ,berlin4 ,price #a4ej net4 ,,problems ,,of ,,genetics4 ,by ,,william ,,bateson1 ,m4,a41 ,f4,r4,s41 ,director of the ,john ,innes ,horticultural ,institution1 ,merton ,park1 ,surrey1 ,england4 7,second printing47 ,price #e4jj net4 ,,stellar ,,motions4 ,with ,special ,reference to ,motions ,determined by ,means of the ,spectrograph4 ,by ,,william ,,wallace ,,campbell1 ,,so4,d1 ,,ll4,d41 ,director of the ,lick ,observatory1 ,university of ,california4 7,second printing47 ,price #e4jj net4 ,,theories ,,of ,,solutions4 ,by ,,svante ,,arrhenius1 ,,ph4,d41 ,,sc4,d41 ,m4,d41 ,director of the ,physico-,chemical ,department of the ,nobel ,institute1 ,stockholm1 ,sweden4 7,third printing47 ,price #c4jj net4 ,,irritability4 ,a ,physiological ,analysis of the ,general ,effect of ,stimuli in ,living ,substances4 ,by ,,max ,,verworn1 ,m4,d41 ,,ph4,d41 ,professor at ,bonn ,physiological ,institute4 7,second printing47 ,price #e4jj net4 ,,problems ,,of ,,american ,,geology4 ,by ,,william ,,north ,,rice1 ,,frank ,d4 ,,adams1 ,,arthur ,p4 ,,coleman1 ,,charles ,d4 ,,walcott1 ,,waldemar ,,lindgren1 ,,frederick ,,leslie ,,ransome1 ,,and ,,william ,d4 ,,matthew4 7,second printing47 ,price #e4jj net4 ,,the ,,problem ,,of ,,volcanism4 ,by ,,joseph ,,paxson ,,iddings1 ,,ph4,d41 ,,sc4,d4 7,second printing47 ,price #e4jj net4 ,,organism ,,and ,,environment ,,as ,,illustrated ,,by ,,the ,,physiology ,,of ,,breathing4 ,by ,,john ,,scott ,,haldane1 ,m4,d41 ,,ll4,d41 ,f4,r4,s41 ,fellow of ,new ,college1 ,oxford ,university4 7,second printing47 ,price #a4be net4 ,a ,,century ,,of ,,science ,,in ,,america ,illustration3 ,b4 ,silliman ,a ,,century ,,of ,,science ,,in ,,america ,,with ,,special ,,reference ,,to ,,the ,,american ,,journal ,,of ,,science #ahah-aiah ,,by ,,edward ,,salisbury ,,dana ,,charles ,,schuchert ,,herbert ,e4 ,,gregory ,,joseph ,,barrell ,,george ,,otis ,,smith ,,richard ,,swann ,,lull ,,louis ,v4 ,,pirsson ,,william ,e4 ,,ford ,r4 ,b4 ,,sosman ,,horace ,l4 ,,wells ,,harry ,w4 ,,foote ,,leigh ,,page ,,wesley ,r4 ,,coe ,,and ,,george ,l4 ,,goodale ,illustration3 ,logo ,,new ,,haven ,,yale ,,university ,,press ,,london ,,humphrey ,,milford ,,oxford ,,university ,,press ,,mdccccxviii ,,copyright1 #aiah1 ,,by ,,yale ,,university ,,press ,,prefatory ,,note ,the present book commemorates the one-hundredth anniversary of the founding of the ,american ,journal of ,science by ,benjamin ,silliman in ,july1 #ahah4 ,the opening chapter gives a somewhat detailed account of the early days of the ,journal1 with a sketch of its subsequent history4 ,the remaining chapters are devoted to the principal branches of science which have been prominent in the pages of the ,journal4 ,they have been written with a view to showing in each case the position of the science in #ahah and the general progress made during the century2 special prominence is given to ,american science and particularly to the contributions to it to be found in the ,journal's pages4 ,references to specific papers in the ,journal are in most cases included in the text and give simply volume1 page1 and date1 as 7#bd1 #aje1 #ahcc72 when these and other references are in considerable number they have been brought together as a ,bibliography at the end of the chapter4 ,the entire cost of the present book is defrayed from the income of the ,mrs4 ,hepsa ,ely ,silliman ,memorial ,fund1 established under the will of ,augustus ,ely ,silliman1 a nephew of ,benjamin ,silliman1 who died in #ahhd4 ,certain of the chapters here printed have been made the basis of a series of seven ,silliman ,lectures in accordance with the terms of that gift4 ,the selection of these lectures has been determined by the convenience of the gentlemen concerned and in part also by the nature of the subject4 ,,table ,,of ,,contents ,page ,prefatory ,note vii ,i4 ,the ,american ,journal of ,science from #ahah to #aiah4 ,edward ,salisbury ,dana #ac ,,ii4 ,a ,century of ,geology3 ,the ,progress of ,historical ,geology in ,north ,america4 ,charles ,schuchert #fj ,,iii4 ,a ,century of ,geology3 ,steps of ,progress in the ,interpretation of ,land ,forms4 ,herbert ,e4 ,gregory #abb ,,iv4 ,a ,century of ,geology 7continued73 ,the ,growth of ,knowledge of ,earth ,structure4 ,joseph ,barrell #aec ,v4 ,a ,century of ,government ,geological ,surveys4 ,george ,otis ,smith #aic ,,vi4 ,on the ,development of ,vertebrate ,paleontology4 ,richard ,swann ,lull #bag ,,vii4 ,the ,rise of ,petrology as a ,science4 ,louis ,v4 ,pirsson #bdh ,,viii4 ,the ,growth of ,mineralogy from #ahah to #aiah4 ,william ,e4 ,ford #bfh ,,ix4 ,the ,work of the ,geophysical ,laboratory of the ,carnegie ,institution of ,washington4 ,r4 ,b4 ,sosman #bhd ,x4 ,the ,progress of ,chemistry during the ,past ,one ,hundred ,years4 ,horace ,l4 ,wells and ,harry ,w4 ,foote #bhh ,,xi4 ,a ,century's ,progress in ,physics4 ,leigh ,page #cce ,,xii4 ,a ,century of ,zoology in ,america4 ,wesley ,r4 ,coe #cia ,,xiii4 ,the ,development of ,botany since #ahah4 ,george ,l4 ,goodale #dci ,,portraits ,benjamin ,silliman ,frontispiece ,from a painting by ,g4 ,s4 ,hubbard1 ,esq41 in possession of ,miss ,henrietta ,w4 ,hubbard ,benjamin ,silliman1 ,jr4 opposite page #bh ,james ,d4 ,dana #cf ,edward ,s4 ,dana #dh ,wolcott ,gibbs #eb ,james ,hall #hd ,g4 ,k4 ,gilbert #adj ,edward ,hitchcock #aef ,o4 ,c4 ,marsh #bcb ,f4 ,v4 ,hayden #aif ,j4 ,w4 ,powell #bjd ,clarence ,king #bjh ,george ,j4 ,brush #bgf ,j4 ,willard ,gibbs #cbd ,h4 ,a4 ,newton #ccf ,james ,clerk ,maxwell #cdh ,louis ,agassiz #djd ,thomas ,h4 ,huxley #daj ,a4 ,e4 ,verrill #dab ,asa ,gray #ddd ,charles ,darwin #deb ,a ,,century ,,of ,,science ,,in ,,america ,i ,,the ,,american ,,journal ,,of ,,science ,,from #ahah ,,to #aiah ,by ,,edward ,s4 ,,dana ,introduction4 ,in ,july1 #ahah1 one hundred years ago1 the first number of the ,american ,journal of ,science and ,arts was given to the public4 ,this is the only scientific periodical in this country to maintain an uninterrupted existence since that early date1 and this honor is shared with hardly more than half a dozen other independent scientific periodicals in the world at large4 ,similar publications of learned societies for the same period are also very few in number4 ,it is interesting1 on the occasion of this centenary1 to glance back at the position of science and scientific literature in the world's intellectual life in the early part of the nineteenth century1 and to consider briefly the marvelous record of combined scientific and industrial progress of the hundred years following--subjects to be handled in detail in the succeeding chapters4 ,it is fitting also that we should recall the man who founded the ,journal1 the conditions under which he worked1 and the difficulties he encountered4 ,finally1 we must review1 but more briefly1 the subsequent history of what has so often been called after its founder1 8,silliman's ,journal40 ,the nineteenth century1 and particularly the hundred years in which we are now interested1 must always stand out in the history of the world as the period which has combined the greatest development in all departments of science with the most extraordinary industrial progress4 ,it was not until this century that scientific investigation used to their full extent the twin methods of observation and experiment4 ,in cases too numerous to mention they have given us first1 a tentative hypothesis2 then1 through the testing and correcting of the hypothesis by newly acquired data1 an accepted theory has been arrived at2 finally1 by the same means carried further has been established one of nature's laws4 ,early ,science4--,looking far back into the past1 it seems surprising that science should have had so late a growth1 but the wonderful record of man's genius in the monuments he erected and in architectural remains shows that the working of the human mind found expression first in art and further man also turned to literature4 ,so far as man's thought was constructive1 the early results were systems of philosophy1 and explanations of the order of things as seen from within1 not as shown by nature herself4 ,we date the real beginning of science with the ,greeks1 but it was the century that preceded ,aristotle that saw the building of the ,parthenon and the sculptures of ,phidias4 ,even the great ,aristotle himself 7#chd-cbb ,b4 ,c47 though he is sometimes called the 8founder of natural history10 was justly accused by ,lord ,bacon many centuries later of having formed his theories first and then to have forced the facts to agree with them4 ,the bringing together of facts through observation alone began1 to be sure1 very early1 for it was the motion of the sun1 moon1 and stars and the relation of the earth to them that first excited interest1 and1 especially in the countries of the ,east1 led to the accumulation of data as to the motion of the planets1 of comets and the occurrence of eclipses4 ,but there was no cordination of these facts and they were so involved in man's superstition as to be of little value4 ,in passing1 however1 it is worthy of mention that the ,chinese astronomical data accumulated more than two thousand years before the ,christian era have in trained hands yielded results of no small significance4 ,doubtless were full knowledge available as to the science existing in the early civilizations1 we should rate it higher than we can at present1 but it would probably prove even then to have been developed from within1 like the philosophies of the ,greeks1 and with but minor influence from nature herself4 ,it is indeed remarkable that down to the time with which we are immediately concerned1 it was the branches of mathematics1 as arithmetic and geometry and later their applications1 that were first and most fully developed3 in other words those lines of science least closely connected with nature4 ,of the importance to science of the ,greek school at ,alexandria in the second and third centuries ,b4 ,c41 there can be no question4 ,the geometry of ,euclid 7about #cjj ,b4 ,c47 was marvelous in its completeness as in clearness of logical method4 ,hipparchus 7about #afj-abe ,b4 ,c47 gave the world the elements of trigonometry and developed astronomy so that ,ptolemy #bfj years later was able to construct a system that was well developed1 though in error in the fundamental idea as to the relative position of the earth4 ,it is interesting to note that the ,almagest of ,ptolemy was thought worthy of republication by the ,carnegie ,institution only a year or two since4 ,this great astronomical work1 by the way1 had no successor till that of the ,arab ,ulugh ,bey in the fifteenth century1 which within a few months has also been made available by the same ,institution4 ,to the ,alexandrian school also belongs ,archimedes 7#bhg-bab ,b4 ,c471 who1 as every school boy knows1 was the founder of mechanics and in fact almost a modern physical experimenter4 ,he invented the water screw for raising water2 he discovered the principle of the lever1 which appealed so keenly to his imagination that he called for a 1 or fulcrum1 on which to place it so as to move the earth itself4 ,he was still nearer to modern physics in his reputed plan of burning up a hostile fleet by converging the sun's rays by a system of great mirrors4 ,to the ,romans1 science owes little beyond what is implied in their vast architectural monuments1 buildings and aqueducts which were erected at home and in the countries of their conquests4 ,the elder ,pliny 7#bc-gi ,a4 ,d47 most nearly deserved to be called a man of science1 but his work on natural history1 comprised in thirty-seven volumes1 is hardly more than a compilation of fable1 fact1 and fancy1 and is sometimes termed a collection of anecdotes4 ,he lost his life in the 8grandest geological event of antiquity10 the eruption of ,vesuvius1 which is vividly described by his nephew1 the younger ,pliny1 in 8one of the most remarkable literary productions in the domain of geology0 7,zittel74 ,with the fall of ,rome and the decline of ,roman civilization came a period of intellectual darkness1 from which the world did not emerge until the revival of learning in the fifteenth and sixteenth centuries4 ,then the extension of geographical knowledge went hand in hand with the development of art1 literature1 and the birth of a new science4 ,copernicus 7#adgc-aedc7 gave the world at last a sun-controlled solar system2 ,kepler 7#aega-afcj7 formulated the laws governing the motion of the planets2 ,galileo 7#aefd-afdb7 with his telescope opened up new vistas of astronomical knowledge and laid the foundations of mechanics2 while ,leonardo da ,vinci 7#adeb-aeai71 painter1 sculptor1 architect1 engineer1 musician and true scientist1 studied the laws of falling bodies and solved the riddle of the fossils in the rocks4 ,still later ,newton 7#afdb-agbg7 established the law of gravitation1 developed the calculus1 put mechanics upon a solid basis and also worked out the properties of lenses and prisms so that his ,optics 7#agjd7 will always have a prominent place in the history of science4 ,from the time of the ,renaissance on science grew steadily1 but it was not till the latter half of the eighteenth century that the foundations in most of the lines recognized to-day were fully laid4 ,much of what was accomplished then is1 at least1 outlined in the chapters following4 ,our standpoint in the early years of the nineteenth century1 just before the ,american ,journal had its beginning1 may be briefly summarized as follows3 ,a desire for knowledge was almost universal and1 therefore1 also a general interest in the development of science4 ,mathematics was firmly established and the mathematical side of astronomy and natural philosophy--as physics was then called--was well developed4 ,many of the phenomena of heat and their applications1 as in the steam engine of ,watt1 were known and even the true nature of heat had been almost established by our countryman1 ,count ,rumford2 but of electricity there were only a few sparks of knowledge4 ,chemistry had had its foundation firmly laid by ,priestley1 ,lavoisier1 and ,dalton1 while ,berzelius was pushing rapidly forward4 ,geology had also its roots down1 chiefly through the work of ,hutton and ,william ,smith1 though the earth was as yet essentially an unexplored field4 ,systematic zoology and botany had been firmly grounded by ,buffon1 ,lamarck and ,cuvier1 on the one hand1 and ,linnus on the other2 but of all that is embraced under the biology of the latter half of the nineteenth century the world knew nothing4 ,the statements of ,silliman in his ,introductory ,remarks in the first number1 quoted in part on a following page1 put the matter still more fully1 but they are influenced by the enthusiasm of the time and he could have had little comprehension of what was to be the record of the next one hundred years4 ,now1 leaving this hasty and incomplete retrospect and coming down to #aiah1 we find the contrast between to-day and #ahah perhaps most strikingly brought out1 on the material side1 if we consider the ability of man1 in the early part of the nineteenth century1 to meet the demands upon him in the matter of transportation of himself and his property4 ,in #ahjj1 he had hardly advanced beyond his ancestor of the earliest civilization2 on the contrary1 he was still dependent for transportation on land upon the muscular efforts of himself and domesticated animals1 while at sea he had only the use of sails in addition4 ,the first application of the steam engine with commercial success was made by ,fulton when1 in #ahjg1 the steamboat 8,clermont0 made its famous trip on the ,hudson ,river4 ,since then1 step by step1 transportation has been made more and more rapid1 economical and convenient1 both on land and water4 ,this has come first through the perfection of the steam engine2 later through the agency of electricity1 and still further and more universally by the use of gasolene motors4 ,finally1 in these early years of the twentieth century1 what seemed once a wild dream of the imagination has been realized1 and man has gained the conquest of the air2 while the perfection of the submarine is as wonderful as its work can be deadly4 ,hardly less marvelous is the practical annihilation of space and time in the electric transmission of human thought and speech by wire and by ether waves4 ,while1 still further1 the same electrical current now gives man his artificial illumination and serves him in a thousand ways besides4 ,but the limitations of space have also been conquered1 during the same period1 by the spectroscope which brings a knowledge of the material nature of the sun and the fixed stars and of their motion in the line of sight2 while spectrum analysis has revealed the existence of many new elements and opened up vistas as to the nature of matter4 ,the chemist and the physicist1 often working together in the investigation of the problems lying between their two departments1 have accumulated a staggering array of new facts from which the principles of their sciences have been deduced4 ,many new elements have been discovered1 in fact nearly all called for by the periodic law2 the so-called fixed gases have been liquefied1 and now air in liquid form is almost a plaything2 the absolute zero has been nearly reached in the boiling point of helium2 physical measurements in great precision have been carried out in both directions for temperatures far beyond any scale that was early conceived possible2 the atom1 once supposed to be indivisible1 has been shown to be made up of the much smaller electrons1 while its disintegration in radium and its derivatives has been traced out and with consequences only as yet partly understood but certainly having far-reaching consequences2 at one point we seem to be brought near to the transmutation of the elements which was so long the dream of the alchemist4 ,still again photography has been discovered and perfected and with the use of ,x-rays it gives a picture of the structure of bodies totally opaque to the eye2 the same ,x-rays seem likely to locate and determine the atoms in the crystal4 ,here and at many other points we are reaching out to a knowledge of the ultimate nature of matter4 ,in geology1 vast progress has been made in the knowledge of the earth1 not only as to its features now exhibited at or near the surface1 but also as to its history in past ages1 of the development of its structure1 the minute history of its life1 the phenomena of its earthquakes1 volcanoes1 etc4 ,geological surveys in all civilized countries have been carried to a high degree of perfection4 ,in biology1 itself a word which though used by ,lamarck did not come into use till taken up by ,huxley1 and then by ,herbert ,spencer in the middle of the century1 the progress is no less remarkable as is well developed in a later chapter of this volume4 ,although not falling within our sphere1 it would be wrong1 too1 not to recognize also the growth of medicine1 especially through the knowledge of bacteria and their functions1 and of disease germs and the methods of combating them4 ,the world can never forget the debt it owes to ,pasteur and ,lister and many later investigators in this field4 ,to follow out this subject further would be to encroach upon the field of the chapters following1 but1 more important and fundamental still than all the facts discovered and the phenomena investigated has been the establishment of certain broad scientific principles which have revolutionized modern thought and shown the relation between sciences seemingly independent4 ,the law of conservation of energy in the physical world and the principle of material and organic evolution may well be said to be the greatest generalizations of the human mind4 ,although suggestions in regard to them1 particularly the latter1 are to be found in the writings of early authors1 the establishment and general acceptance of these principles belong properly to the middle of the nineteenth century4 ,they stand as the crowning achievement of the scientific thought of the period in which we are interested4 ,any mere enumeration of the vast fund of knowledge accumulated by the efforts of man through observation and experiment in the period in which we are interested would be a dry summary1 and yet would give some measure of what this marvelous period has accomplished4 ,as in geography1 man's energy has in recent years removed the reproach of a 8,dark ,continent10 of 8unexplored0 central ,asia and the once 8inaccessible polar regions10 so in the different departments of science1 he has opened up many unknown fields and accumulated vast stores of knowledge4 ,it might even seem as if the limit of the unknown were being approached4 ,there remains1 however1 this difference in the analogy1 that in science the fundamental relations--as1 for example1 the nature of gravitation1 of matter1 of energy1 of electricity2 the actual nature and source of life--the solution of these and other similar problems still lies in the future4 ,what the result of continued research may be no one can predict1 but even with these possibilities before us1 it is hardly rash to say that so great a combined progress of pure and applied science as that of the past hundred years is not likely to be again realized4 ,scientific ,periodical ,literature in #ahah4 ,the contrast in scientific activity between #ahah and #aiah is nowhere more strikingly shown than in the amount of scientific periodical literature of the two periods4 ,of the thousands of scientific journals and regular publications by scientific societies and academies to-day1 but a very small number have carried on a continuous and practically unbroken existence since #ahah4 ,this small amount of periodical scientific literature in the early part of the last century is significant as giving a fair indication of the very limited extent to which scientific investigation appealed to the intellectual life of the time4 ,some definite facts in regard to the scientific publications of those early days seem to be called for4 ,learned societies and academies1 devoted to literature and science1 were formed very early but at first for occasional meetings only and regular publications were in most cases not begun till a very much later date4 ,some of the earliest--not to go back of the ,renaissance--are the following3 #aefj4 ,naples1 ,academia ,secretorum ,natur4 #afjc4 ,rome1 ,accademia dei ,lincei4 #afea4 ,leipzig1 ,academia ,natur ,curiosum4 #afeg4 ,florence1 ,accademia del ,cimento4 #affb4 ,london1 ,royal ,society4 #afff4 ,paris1 ,acadmie des ,sciences4 #afij4 ,bologna1 ,accademia delle ,scienze4 #agjj4 ,berlin1 ,societas ,regia ,scientiarum4 ,this was the forerunner of the ,k4 preuss4 ,akad4 d4 ,wissenschaften4 ,the ,royal ,society of ,london1 whose existence dates from #afde1 though not definitely chartered until #affb1 began the publication of its 8,philosophical ,transactions0 in #affe and has continued it practically unbroken to the present time2 this is a unique record4 ,following this1 other early--but in most cases not continuous--publications were those of ,paris 7#afii72 ,berlin 7#agaj72 ,upsala 7#agbj72 ,petrograd1 #agbh2 ,stockholm 7#agci72 and ,copenhagen 7#agdc74 ,for the latter half of the eighteenth century1 when the foundations of our modern science were being rapidly laid1 a considerable list might be given of early publications of similar scientific bodies4 ,some of the prominent ones are3 ,gttingen 7#agej71 ,munich 7#agei71 ,brussels 7#agfi71 ,prague 7#agge71 ,turin 7#aghd71 ,dublin 7#aghh71 etc4 ,the early years of the nineteenth century saw the beginnings of many others1 particularly in northern ,italy4 ,it is to be noted that1 as stated1 only rarely were the publications of these learned societies even approximately continuous4 ,in the majority of cases the issue of transactions or proceedings was highly irregular and often interrupted4 ,in this country the earliest scientific bodies are the following3 ,philadelphia4 ,american ,philosophical ,society1 founded in #agdc4 ,transactions were published #agga-ahji2 then interrupted until #ahah et seq4 ,boston4 ,american ,academy of ,arts and ,sciences1 founded in #aghj4 ,memoirs1 #aghe-ahba2 and then #ahcc et seq4 ,new ,haven4 ,connecticut ,academy of ,arts and ,sciences1 begun in #agii4 ,memoirs1 vol4 #a1 #ahaj-af2 ,transactions1 #ahff et seq4 ,philadelphia4 ,academy of ,natural ,sciences1 begun in #ahab4 ,journal1 #ahag-ahdb2 and from #ahdg et seq4 ,new ,york4 ,lyceum of ,natural ,history1 #ahag2 later 7#ahgf7 became the ,new ,york ,academy of ,sciences4 ,annals from #ahbc2 ,proceedings from #ahgj4 ,the situation is somewhat similar as to independent scientific journals4 ,a list of the names of those started only to find an early death would be a very long one1 but interesting only historically and as showing a spasmodic but unsustained striving after scientific growth4 ,it seems worth while1 however1 to give here the names of the periodicals embracing one or more of the subjects of the ,american ,journal1 which began at a very early date and most of which have maintained an uninterrupted existence down to #aiae4 ,it should be added that certain medical journals1 not listed here1 have also had a long and continued existence4#a ,early ,scientific ,journals4 #agga-ahbc4 ,journal de ,physique1 ,paris2 title changed several times4 #aghg-4 ,botanical ,magazine4 7,for a time known as ,curtis's ,journal74 #aghi-ahaf4 ,annales de ,chimie1 ,paris4 ,continued from #ahag on as the ,annales de ,chimie et de ,physique4 #agij4 ,journal der ,physik1 ,halle 7by ,gren72 from #agii on became the ,annalen der ,physik 7und ,chemie71 ,halle1 ,leipzig4 ,the title has been somewhat changed from time to time though publication has been continuous4 ,often referred to by the name of the editor-in-chief1 as ,gren1 ,gilbert1 ,poggendorff1 ,wiedemann1 etc4 #agie-ahae4 ,journal des ,mines1 ,paris1 continued from #ahaf as the ,annales des ,mines4 #agif-ahae4 ,bibliothque ,britannique1 ,geneva4 ,from #ahaf-ahdj1 ,bibliothque ,universelle1 etc4 #ahdf-aheg1 ,archives des ,sci4 phys4 nat4 ,since #aheh generally known as the ,bibliothque ,universelle4 #agig4 ,journal of ,natural ,philosophy1 ,chemistry and the ,arts 7,nicholson's ,journal7 ,london2 united in #ahad with the ,philosophical ,magazine 7,tilloch's ,journal74 #agih-4 ,the ,philosophical ,magazine 7originally by ,tilloch74 ,this absorbed ,nicholson's ,journal 7above7 in #ahad2 also the ,annals of ,philosophy 7,thomson1 ,phillips7 in #ahbg and ,brewsters' ,edinburgh ,journal of ,science in #ahcb4 #agih-ahjc4 ,allgemeines ,journal der ,chemie 7,scherer's ,journal74 #ahjc-ahjf2 continued as ,neues ,allg4 ,j4 etc4 7,gehlen's ,journal74 ,later title repeatedly changed and finally 7#ahcd et seq47 ,journal fr praktische ,chemie4 #ahaf-ah4 ,journal of ,science and the ,arts1 ,london4 #ahaicj1 ,quarterly ,j4 etc4 #ahcj-ca1 ,journal of the ,royal ,institution of ,great ,britain4 #ahah4 ,american ,journal of ,science and ,arts until #ahhj1 when 8the ,arts0 was dropped1 ,new ,haven1 ,conn4 ,first ,series1 #a-ej1 #ahah-ahde2 ,second ,series1 #a-ej1 #ahdf-ahgj2 ,third ,series1 #a-ej1 #ahga-ahie2 ,fourth ,series1 #a-de1 #ahif-;,june1 #aiah4 #ahah4 ,flora1 or ,allgemeine botanische ,zeitung4 ,regensburg1 ,munich4 #ahbj-ahfg4 ,london ,journal of ,arts and ,sciences 7after #ahee1 ,newton's ,journal74 #ahbd-4 ,annales des sciences naturelles4 ,paris4 #ahbf-4 ,linna1 ,berlin1 ,halle2 from #ahhb united with ,jahrb4 d4 ,k4 botan4 ,gartens4 #ahbh-ahdj4 ,magazine of ,natural ,history1 ,london2 united #ahch with the ,annals of ,natural ,history1 and known since #ahda as the ,annals and ,magazine of ,natural ,history4 #ahbh-4 ,journal of the ,franklin ,institute1 ,philadelphia1 from #ahbf2 earlier 7#ahbe7 the ,american ,mechanics ,magazine4 #ahcb-4 ,annalen der ,chemie 7und ,pharmacie7 often known as ,liebig's ,annalen4 ,leipzig1 ,lemgo4 ,the ,founder of the ,american ,journal of ,science4 ,the establishment of a scientific journal in this country in #ahah was a pioneer undertaking1 requiring of its founder a rare degree of energy1 courage1 and confidence in the future4 ,it was necessary1 not only to obtain the material to fill its pages and the money to carry on the enterprise1 but1 before the latter end could be accomplished1 an audience must be found among those who had hitherto felt little or no interest in the sciences4 ,this great work was accomplished by ,benjamin ,silliman1 8the guardian of ,american ,science10 whose influence was second to none in the early development of science in this country4 ,before speaking in some detail of the early years of this ,journal and of its subsequent history1 it is proper that some words should be given to its founder4 ,benjamin ,silliman1 son of a general prominent in the ,revolutionary ,war1 was born in ,trumbull1 ,connecticut1 on ,august #h1 #aggi4 ,he was a graduate of ,yale ,college of the class of #agif4 ,though at first a student of law and accepted for the bar in ,connecticut1 he was called in #ahjb by ,president ,timothy ,dwight--a man of rare breadth of mind--to occupy the newly made chair of chemistry1 mineralogy 7and later geology7 in ,yale ,college at ,new ,haven4 ,to fit himself for the work before him he carried on extensive studies at home and in ,philadelphia and spent the year #ahje in travels and study at ,london and ,edinburgh1 and also on the ,continent4 ,his active duties began in #ahjf and from this time on he was in the service of ,yale ,college until his resignation in #ahec4 ,from the first1 ,silliman met with remarkable success as a teacher and public lecturer in arousing an interest in science4 ,his breadth of knowledge1 his enthusiasm for his chosen subjects and power of clear presentation1 combined with his fine presence and attractive personality1 made him a great leader in the science of the country and gave him a unique position in the history of its development4 ,much might be said of the man and his work1 but1 the best tribute is that of ,james ,dwight ,dana1 given in his inaugural address upon the occasion of his beginning his duties as ,silliman professor of geology in ,yale ,college4 ,this was delivered on ,february #ah1 #ahef1 in what was then known as the 8,cabinet ,building40 ,dana says in part3 8,in entering upon the duties of this place1 my thoughts turn rather to the past than to the subject of the present hour4 ,i feel that it is an honored place1 honored by the labors of one who has been the guardian of ,american ,science from its childhood2 who here first opened to the country the wonderful records of geology2 whose words of eloquence and earnest truth were but the overflow of a soul full of noble sentiments and warm sympathies1 the whole throwing a peculiar charm over his learning1 and rendering his name beloved as well as illustrious4 ,just fifty years since1 ,professor ,silliman took his station at the head of chemical and geological science in this college4 ,geology was then hardly known by name in the land1 out of these walls4 ,two years before1 previous to his tour in ,europe1 the whole cabinet of ,yale was a half-bushel of unlabelled stones4 ,on visiting ,england he found even in ,london no school public or private1 for geological instruction1 and the science was not named in the ,english universities4 ,to the mines1 quarries1 and cliffs of ,england1 the crags of ,scotland1 and the meadows of ,holland he looked for knowledge1 and from these and the teachings of ,murray1 ,jameson1 ,hall1 ,hope1 and ,playfair1 at ,edinburgh1 ,professor ,silliman returned1 equipped for duty1--albeit a great duty1--that of laying the foundation1 and creating almost out of nothing a department not before recognized in any institution in ,america4 ,he began his work in #ahjf4 ,the science was without books--and1 too1 without system1 except such as its few cultivators had each for himself in his conceptions4 ,it was the age of the first beginnings of geology1 when ,wernerians and ,huttonians were arrayed in a contest4444 ,professor ,silliman when at ,edinburgh witnessed the strife1 and while1 as he says1 his earliest predilections were for the more peaceful mode of rock-making1 these soon yielded to the accumulating evidence1 and both views became combined in his mind in one harmonious whole4 ,the science1 thus evolved1 grew with him and by him2 for his own labors contributed to its extension4 ,every year was a year of expansion and onward development1 and the grandeur of the opening views found in him a ready and appreciative response4444 ,and while the sciences and truth have thus made progress here1 through these labors of fifty years1 the means of study in the institution have no less increased4 ,instead of that half-bushel of stones1 which once went to ,philadelphia for names1 in a candle-box1 you see above the largest mineral cabinet in the country1 which but for ,professor ,silliman1 his attractions and his personal exertions together1 would never have been one of the glories of old ,yale4444 ,moreover1 the ,american ,journal of ,science1--now in its thirty-seventh year and seventieth volume #ahef1--projected and long-sustained solely by ,professor ,silliman1 while ever distributing truth1 has also been ever gathering honors1 and is one of the laurels of ,yale4 ,we rejoice that in laying aside his studies1 after so many years of labor1 there is still no abated vigor4444 ,he retires as one whose right it is to throw the burden on others4 ,long may he be with us1 to enjoy the good he has done1 and cheer us by his noble and benign presence40 ,in addition to these words of ,dana1 much of vital interest in regard to ,silliman and his work will be gathered from what is given in the pages immediately following1 quoted from his personal statements in the early volumes of the ,journal4 ,the ,early ,years of the ,journal4 ,in no direction did ,silliman's enthusiastic activities in science produce a more enduring result than in the founding and carrying on of the ,journal4 ,the first suggestion in regard to the enterprise was made to ,silliman by his friend1 ,colonel ,george ,gibbs1 from whom the famous ,gibbs collection of minerals was bought by ,yale ,college in #ahbe4 ,silliman says 7#be1 #bae1 #ahcd73 ,illustration3 ,,the ,,american ,,journal ,,of ,,science1 ,,more ,,especially ,,of ,,mineralogy1 ,,geology1 ,,and ,,the ,,other ,,branches ,,of ,,natural ,,history2 ,,including ,,also ,,agriculture ,,and ,,the ,,ornamental ,,as ,,well ,,as ,,useful ,,arts4 ,,conducted ,,by ,,benjamin ,,silliman1 ,,professor ,,of ,,chemistry1 ,,mineralogy1 ,,etc4 ,,in ,,yale ,,college1 ,,author ,,of ,,travels ,,in ,,england1 ,,scotland1 ,,and ,,holland1 ,,etc4 ,,vol4 ,i4 444 ,,no4 ,i4 ,,engraving ,,in ,,the ,,present ,,no4 ,new apparatus for the combustion of ,,tar1 c4 by the vapour of water4 ,new ,york3 ,,published ,,by ,j4 ,,eastburn ,,and ,,co4 ,,literary ,,rooms1 ,,broadway1 ,,and ,,by ,,howe ,,and ,,spalding1 ,,new-,,haven ,abraham ,paul1 printer4 #ahah4 8,col4 ,gibbs was the person who first suggested to the ,editor the project of this ,journal1 and he urged the topic with so much zeal and with such cogent arguments1 as prevailed to induce the effort in a case then viewed as of very dubious success4 ,the subject was thus started in ,november1 #ahag2 proposals for the ,journal were issued in ,january1 #ahah1 and the first number appeared in ,july of that year40 ,he adds further 7#ej1 p4 iii1 #ahdg7 that the conversation here recorded took place 8on an accidental meeting on board the steamboat ,fulton in ,long ,island ,sound40 ,this was some ten years after ,robert ,fulton's steamboat1 the ,clermont1 made its pioneer trip on the ,hudson river1 already alluded to4 ,the incident is not without significance in this connection4 ,the deck of the 8,fulton0 was not an inappropriate place for the inauguration of an enterprise also great in its results for the country4 ,in the preface to the concluding volume of the ,first ,series 7loc4 cit47 ,silliman adds the following remarks which show his natural modesty at the thought of undertaking so serious a work4 ,he says3 ,although a different selection of an editor would have been much preferred1 and many reasons1 public and personal1 concurred to produce diffidence of success1 the arguments of ,col4 ,gibbs1 whose views on subjects of science were entitled to the most respectful consideration1 and had justly great weight1 being pressed with zeal and ability1 induced a reluctant assent2 and accordingly1 after due consultation with many competent judges1 the proposals were issued early in #ahah1 embracing the whole range of physical science and its applications4 ,the ,editor in entering on the duty1 regarded it as an affair for life1 and the thirty years of experience which he has now had1 have proved that his views of the exigencies of the service were not erroneous4 ,the plan with which the editor began his work and the lines laid down by him at the outset can only be made clear by quoting entire the 8,plan of the ,work0 which opens the first number4 ,it seems desirable also to give this in its original form as to paragraphs and typography4 ,the first page of the cover of the opening number has also been reproduced here4 ,it will be seen that the plan of the young editor was as wide as the entire range of science and its applications and extended out to music and the fine arts4 ,this seems strange to-day1 but it must be remembered how few were the organs of publication open to contributors at the time4 ,if the plan was unreasonably extended1 that fact is to be taken not only as an expression of the enthusiasm of the editor1 as yet inexperienced in his work1 but also of the time when the sciences were still in their infancy4 ,he says 7#a1 pp4 v1 vi73 8,,plan ,,of ,,the ,,work4 ,this ,journal is intended to embrace the circle of ,,the ,,physical ,,sciences1 with their application to ,,the ,,arts1 and to every useful purpose4 ,it is designed as a deposit for original ,american communications2 but will contain also occasional selections from ,foreign ,journals1 and notices of the progress of science in other countries4 ,within its plan are embraced ,,natural ,,history1 in its three great departments of ,,mineralogy1 ,,botany1 and ,,zoology2 ,,chemistry and ,,natural ,,philosophy1 in their various branches3 and ,,mathematics1 pure and mixed4 ,it will be a leading object to illustrate ,,american ,,natural ,,history1 and especially our ,,mineralogy and ,,geology4 ,the ,,applications of these sciences are obviously as numerous as physical arts1 and physical wants2 for no one of these arts or wants can be named which is not connected with them4 ,while ,,science will be cherished for its own sake1 and with a due respect for its own inherent dignity2 it will also be employed as the handmaid to the ,arts4 ,its numerous applications to ,,agriculture1 the earliest and most important of them2 to our ,,manufactures1 both mechanical and chemical2 and to our ,,domestic ,,economy1 will be carefully sought out1 and faithfully made4 ,it is also within the design of this ,journal to receive communications on ,,music1 ,,sculpture1 ,,engraving1 ,,painting1 and generally on the fine and liberal1 as well as useful arts2 ,on ,military and ,civil ,engineering1 and the art of ,navigation4 ,illustration3 ,very truly ,yours1 ,b4 ,silliman ,notices1 ,reviews1 and ,analyses of new scientific works1 and of new ,inventions1 and ,specifications of ,patents2 ,biographical and ,obituary ,notices of scientific men2 essays on ,,comparative ,,anatomy and ,,physiology1 and generally on such other branches of medicine as depend on scientific principles2 ,meteorological ,registers1 and ,reports of ,agricultural ,experiments3 and we would leave room also for interesting miscellaneous things1 not perhaps exactly included under either of the above heads4 ,communications are respectfully solicited from men of science1 and from men versed in the practical arts4 ,learned ,societies are invited to make this ,journal1 occasionally1 the vehicle of their communications to the ,public4 ,the editor will not hold himself responsible for the sentiments and opinions advanced by his correspondents2 but he will consider it as an allowed liberty to make slight verbal alterations1 where errors may be presumed to have arisen from inadvertency40 ,in the 8,advertisement0 which precedes the above statement in the first number1 the editor remarks somewhat navely that he 8does not pledge himself that all the subjects shall be touched upon in every number4 ,this is plainly impossible unless every article should be very short and imperfect44440 ,the whole subject is discussed in all its relations in the 8,introductory ,remarks0 which open the first volume4 ,no apology is needed for quoting at considerable length1 for only in this way can the situation be made clear1 as seen by the editor in #ahah4 ,further we gain here a picture of the intellectual life of the times and1 not less interesting1 of the mind and personality of the writer4 ,with a frank kindliness1 eminently characteristic of the man1 as will be seen1 he takes the public fully into his confidence4 ,in the remarks made in subsequent volumes1--also extensively quoted--the vicissitudes in the conduct of the enterprise are brought out and when success was no longer doubtful1 there is a tone of quiet satisfaction which was also characteristic and which the circumstances fully justified4 ,the ,,introductory ,,remarks begin as follows3 ,the age in which we live is not less distinguished by a vigorous and successful cultivation of physical science1 than by its numerous and important applications to the practical arts1 and to the common purposes of life4 ,in every enlightened country1 men illustrious for talent1 worth and knowledge1 are ardently engaged in enlarging the boundaries of natural science2 and the history of their labors and discoveries is communicated to the world chiefly through the medium of scientific journals4 ,the utility of such journals has thus become generally evident2 they are the heralds of science2 they proclaim its toils and its achievements2 they demonstrate its intimate connection as well with the comfort1 as with the intellectual and moral improvement of our species2 and they often procure for it enviable honors and substantial rewards4 ,mention is then made of the journals existing in ,england and ,france in #ahah 8which have long enjoyed a high and deserved reputation40 ,he then continues3 ,from these sources our country reaps and will long continue to reap1 an abundant harvest of information3 and if the light of science1 as well as of day1 springs from the ,east1 we will welcome the rays of both2 nor should national pride induce us to reject so rich an offering4 ,but can we do nothing in return8 ,in a general diffusion of useful information through the various classes of society1 in activity of intellect and fertility of resource and invention1 producing a highly intelligent population1 we have no reason to shrink from a comparison with any country4 ,but the devoted cultivators of science in the ,united ,states are comparatively few3 they are1 however1 rapidly increasing in number4 ,among them are persons distinguished for their capacity and attainments1 and1 notwithstanding the local feelings nourished by our state sovereignties1 and the rival claims of several of our larger cities1 there is evidently a predisposition towards a concentration of effort1 from which we may hope for the happiest results1 with regard to the advancement of both the science and reputation of our country4 ,is it not1 therefore1 desirable to furnish some rallying point1 some object sufficiently interesting to be nurtured by common efforts1 and thus to become the basis of an enduring1 common interest8 ,to produce these efforts1 and to excite this interest1 nothing1 perhaps1 bids fairer than a ,,scientific ,,journal4 ,the valuable work already accomplished by various medical journals is then spoken of and particularly that of the first scientific periodical in the ,united ,states1 ,bruce's ,mineralogical ,journal4 ,this1 as ,silliman says 7#a1 p4 #c1 #ahah71 although 8both in this country and in ,europe received in a very flattering manner10 did not survive the death of its founder1 and only a single volume of #bgj pages appeared 7#ahaj-ahac74 ,silliman continues3 ,no one1 it is presumed1 will doubt that a journal devoted to science1 and embracing a sphere sufficiently extensive to allure to its support the principal scientific men of our country1 is greatly needed2 if cordially supported1 it will be successful1 and if successful1 it will be a great public benefit4 ,even a failure1 in so good a cause1 7unless it should arise from incapacity or unfaithfulness17 cannot be regarded as dishonourable4 ,it may prove only that the attempt was premature1 and that our country is not yet ripe for such an undertaking2 for without the efficient support of talent1 knowledge1 and money1 it cannot long proceed4 ,no editor can hope to carry forward such a work without the active aid of scientific and practical men2 but1 at the same time1 the public have a right to expect that he will not be sparing of his own labour1 and that his work shall be generally marked by the impress of his own hand4 ,to this extent the editor cheerfully acknowledges his obligations to the public2 and it will be his endeavour faithfully to redeem his pledge4 ,most of the periodical works of our country have been short-lived4 ,this1 also1 may perish in its infancy2 and if any degree of confidence is cherished that it will attain a maturer age1 it is derived from the obvious and intrinsic importance of the undertaking2 from its being built upon permanent and momentous national interests2 from the evidence of a decided approbation of the design1 on the part of gentlemen of the first eminence1 obtained in the progress of an extensive correspondence2 from assurance of support1 in the way of contributions1 from men of ability in many sections of the union2 and from the existence of such a crisis in the affairs of this country and of the world1 as appears peculiarly auspicious to the success of every wise and good undertaking4 ,an interesting discussion follows 7pp4 #e-h7 as to the claims of the different branches of science1 and the extent to which they and their applications had been already developed1 also the spheres still open to discovery4 ,the ,introductory ,remarks close1 as follows3 ,in a word1 the whole circle of physical science is directly applicable to human wants and constantly holds out a light to the practical arts2 it thus polishes and benefits society and everywhere demonstrates both supreme intelligence and harmony and beneficence of design in the ,creator4 ,the science of mathematics1 both pure and mixed1 can never cease to be interesting and important to man1 as long as the relations of quantity shall exist1 as long as ships shall traverse the ocean1 as long as man shall measure the surface or heights of the earth on which he lives1 or calculate the distances and examine the relations of the planets and stars2 and as long as the iron reign of war shall demand the discharge of projectiles1 or the construction of complicated defences4 ,the closing part of the paragraph shows the influence exerted upon the mind of the editor by the serious wars of the years preceding #ahah1 a subject alluded to again at the close of this chapter4 ,in ,february1 #ahbb1 with the completion of the fourth volume1 the editor reviews the situation which1 though encouraging is by no means fully assuring4 ,he says 7preface to vol4 #d1 dated ,feb4 #ae1 #ahbb73 ,two years and a half have elapsed1 since the publication of the first volume of this ,journal1 and one year and ten months since the ,editor assumed the pecuniary responsibility4444 ,the work has not1 even yet1 reimbursed its expenses1 7we speak not of editorial or of business compensation17 we intend1 that it has not paid for the paper1 printing and engraving2 the proprietors of the first volume being in advance1 on those accounts1 and the ,editor on the same score1 with respect to the aggregate expense of the three last volumes4 ,this deficit is1 however1 no longer increasing1 as the receipts1 at present1 just about cover the expense of the physical materials1 and of the manual labour4 ,a reiterated disclosure of this kind is not grateful1 and would scarcely be manly1 were it not that the public1 who alone have the power to remove the difficulty1 have a right to a frank exposition of the state of the case4 ,as the patronage is1 however1 growing gradually more extensive1 it is believed that the work will be eventually sustained1 although it may be long before it will command any thing but gratuitous intellectual labour4444 ,these facts1 with the obvious one1--that its pages are supplied with contributions from all parts of the ,union1 and occasionally from ,europe1 evince that the work is received as a national and not as a local undertaking1 and that the community consider it as having no sectional character4 ,encouraged by this view of the subject1 and by the favour of many distinguished men1 both at home and abroad1 and supported by able contributors1 to whom the ,editor again tenders his grateful acknowledgments1 he will still persevere1 in the hope of contributing something to the advancement of our science and arts1 and towards the elevation of our national character4 ,in the autumn of the same year1 the editor closes the fifth volume with a more confident tone 7,sept4 #be1 #ahbb73 ,a trial of four years has decided the point1 that the ,american ,public will support this ,journal4 ,its pecuniary patronage is now such1 that although not a lucrative1 it is no longer a hazardous enterprise4 ,it is now also decided1 that the intellectual resources of the country are sufficient to afford an unfailing supply of valuable original communications and that nothing but perseverance and effort are necessary to give perpetuity to the undertaking4 ,the decided and uniform expression of public favour which the ,journal has received both at home and abroad1 affords the ,editor such encouragement1 that he cannot hesitate to persevere--and he now renews the expression of his thanks to the friends and correspondents of the work1 both in ,europe and the ,united ,states1 requesting at the same time a continuance of their friendly influence and efforts4 ,still again in the preface to the sixth volume 7#ahbc7 he takes the reader more fully into his confidence and shows that he regards the enterprise as no longer of doubtful success4 ,he says3 ,the conclusion of a new volume of a work1 involving so much care1 labour and responsibility1 as are necessarily attached1 at the present day1 to a ,journal of ,science and the ,arts1 naturally produces in the mind1 a state of not ungrateful calmness1 and a disposition1 partaking of social feeling1 to say something to those who honour such a production1 by giving to it a small share of their money1 and of their time4 ,the ,editor's first impression was1 that the sixth volume should be sent into the world without an introductory note1 but he yields to the impulse already expressed1 and to the established usages of respectful courtesy to the public1 which a short preface seems to imply4 ,he has now persevered almost five years1 in an undertaking1 regarded by many of the friends whom he originally consulted1 as hazardous1 and to which not a few of them prophetically alloted only an ephemeral existence4 ,it has been his fortune to prosecute this work without1 7till a very recent period17 returns1 adequate to its indispensable responsibilities2--under a heavy pressure of professional and private duty2 with trying fluctuations of health1 and amidst severe and reiterated domestic afflictions4 ,the world are usually indulgent to allusions of this nature1 when they have any relation to the discharge of public duty2 and in this view1 it is with satisfaction1 that the ,editor adds1 that he has now to look on formidable difficulties1 only in retrospect1 and with something of the feeling of him1 who sees a powerful and vanquished foe1 slowly retiring1 and leaving a field no longer contested4 ,this ,journal which1 from the first1 was fully supplied with original communications1 is now sustained by actual payment1 to such an extent1 that it may fairly be considered as an established work2 its patronage is regularly increasing1 and we trust it will no longer justify such remarks as some of the following1 from the pen of one of the most eminent scientific men in ,europe4 8,nothing surprises me more1 than the little encouragement which your ,journal10 78which ,i always read with very great interest1 and of which ,i make great use107 8experiences in ,america--this must surely arise from the present depressed condition of trade1 and cannot long continue40 ,six years more of uninterrupted editorial work passed by1 the sixteenth volume was completed1 and the editor was now in a position to review the whole situation up to #ahbi4 ,this preface 7dated ,july #a1 #ahbi71 which is quoted nearly in full1 cannot fail to be found particularly interesting and from several standpoints1 not the least for the insight it gives into the writer's mind4 ,it is also noteworthy that at this early date it was found possible to pay for original contributions1 a privilege far beyond the means of the editor of to-day4 ,when this ,journal was first projected1 very few believed that it would succeed4 ,among others1 ,dr4 ,dorsey wrote to the editor2 8,i predict a short life for you1 although ,i wish1 as the ,spaniards say1 that you may live a thousand years40 ,the work has not lived a thousand years1 but as it has survived more than the hundredth part of that period1 no reason is apparent why it may not continue to exist4 ,to the contributors1 disinterested and arduous as have been their exertions1 the editor's warmest thanks are due2 and they are equally rendered to numerous personal friends for their unwavering support3 nor ought those subscribers to be forgotten who1 occupied in the common pursuits of life1 have aided1 by their money1 in sustaining the hazardous novelty of an ,american ,journal of ,science4 ,a general approbation1 sufficiently decided to encourage effort1 where there was no other reward1 has supported the editor2 but he has not been inattentive to the voice of criticism1 whether it has reached him in the tones of candor and kindness1 or in those of severity4 ,we must not look to our friends for the full picture of our faults4 ,he is unwise who neglects the maxim-- --fas est ab hoste doceri1 and we may be sure1 that those are quite in earnest1 whose pleasure it is1 to place faults in a strong light and bold relief2 and to throw excellencies into the shadow of total eclipse4 ,minds at once enlightened and amiable1 viewing both in their proper proportions1 will however render the equitable verdict2 ,non ego paucis offendar maculis1-- ,it is not pretended that this ,journal has been faultless2 there may be communications in it which had been better omitted1 and it is not doubted that the power to command intellectual effort1 by suitable pecuniary reward1 would add to its purity1 as a record of science1 and to its richness1 as a repository of discoveries in the arts4 ,but the editor1 even now1 offers payment1 at the rate adopted by the literary ,journals1 for able original communications1 containing especially important facts1 investigations and discoveries in science1 and practical inventions in the useful and ornamental ,arts4 ,as however his means are insufficient to pay for all the copy1 it is earnestly requested1 that those gentlemen1 who1 from other motives1 are still willing to write for this ,journal1 should continue to favor it with their communications4 ,that the period when satisfactory compensation can be made to all writers whose pieces are inserted1 and to whom payment will be acceptable1 is not distant1 may perhaps be hoped1 from the spontaneous expression of the following opinion1 by the distinguished editor of one of our principal literary journals1 whose letter is now before me4 8,the character of the ,american ,journal is strictly national1 and it is the only vehicle of communication in which an inquirer may be sure to find what is most interesting in the wide range of topics1 which its design embraces4 ,it has become in short1 not more identified with the science than the literature of the country40 ,it is believed that a strict examination of its contents will prove that its character has been decidedly scientific2 and the opinion is often expressed to the editor1 that in common with the journals of our ,academies1 it is a work of reference1 indispensable to him who would examine the progress of ,american science during the period which it covers4 ,that it might not be too repulsive to the general reader1 some miscellaneous pieces have occasionally occupied its pages2 but in smaller proportion1 than is common with several of the most distinguished ,british ,journals of ,science4 ,still1 the editor has been frequently solicited1 both in public and private1 to make it more miscellaneous1 that it might be more acceptable to the intelligent and well educated man1 who does not cultivate science2 but he has never lost sight of his great object1 which was to produce and concentrate original ,american effort in science1 and thus he has foregone pecuniary returns1 which by pursuing the other course1 might have been rendered important4 ,others would not have him admit any thing that is not strictly and technically scientific2 and would make this journal for mere professors and amateurs2 especially in regard to those numerous details in natural history1 which although important to be registered1 7and which1 when presented1 have always been recorded in the ,american ,journal17 can never exclusively occupy the pages of any such work without repelling the majority of readers4 ,if this is true even in ,great ,britain it is still more so in this country2 and our savants1 unless they would be1 not only the exclusive admirers1 but the sole purchasers of their own works1 must permit a little of the graceful drapery of general literature to flow around the cold statues of science4 ,the editor of this ,journal1 strongly inclined1 both from opinion and habit1 to gratify the cultivators of science1 will still do everything in his power to promote its high interests1 and as he hopes in a better manner than heretofore2 but these respectable gentlemen will have the courtesy1 to yield something to the reading literary1 as well as scientific public1 and will not1 we trust1 be disgusted1 if now and then an ,oasis relieves the eye1 and a living stream refreshes the traveller4 ,not being inclined to renew the abortive experiment1 to please every body1 which has been so long renowned in fable2 the editor will endeavor to pursue1 the even tenor of his way2 altogther inclined to be courteous and useful to his fellow travellers1 and hoping for their kindness and services in return4 ,the ,close of the ,first ,series4 ,the 8,first ,series10 as it was henceforth to be known1 closed with the fiftieth volume 7#ahdg1 pp4 xx #cdg74 ,this final volume is devoted to an exhaustive index to the forty-nine volumes preceding4 ,in the preface 7dated ,april #ai1 #ahdg7 the elder ,silliman1 now the senior editor1 reviews the work that had been accomplished with a frank expression of his feeling of satisfaction in the victory won against great obstacles2 with this every reader must sympathize4 ,he quotes here at length 7but in slightly altered form7 the matter from the first volume 7#ahah71 which has been already reproduced almost entire1 and then goes on as follows 7pp4 xi et seq473 ,illustration3 ,james ,d4 ,dana ,such was the pledge which1 on entering upon our editorial labors in #ahah1 we gave to the public1 and such were the views which we then entertained1 regarding science and the arts as connected with the interests and honor of our country and of mankind4 ,in the retrospect1 we realize a sober but grateful feeling of satisfaction1 in having1 to the extent of our power1 discharged these self-imposed obligations2 this feeling is chastened also by a deep sense of gratitude1 first to ,god for life and power continued for so high a purpose2 and next1 to our noble band of contributors1 whose labors are recorded in half a century of volumes1 and in more than a quarter of a century of years4 ,we need not conceal our conviction1 that the views expressed in these 8,introductory ,remarks10 have been fully sustained by our fellow laborers4 ,should we appear to take higher ground than becomes us1 we find our vindication in the fact1 that we have heralded chiefly the doings and the fame of others4 ,the work has indeed borne throughout 8the impress0 of editorial unity of design1 and much that has flowed from one pen1 and not a little from the pens of others1 has been without a name4 ,the materials for the pile1 have however been selected and brought in1 chiefly by other hands1 and if the monument which has been reared should prove to be 8aere perennius10 the honor is not the sole property of the architect2 those who have quarried1 hewn and polished the granite and the marble1 are fully entitled to the enduring record of their names already deeply cut into the massy blocks1 which themselves have furnished4 ,if a retrospective survey of the labors of thirty years on this occasion has rekindled a degree of enthusiasm1 it is a natural result of an examination of all our volumes from the contents of which we have endeavored to make out a summary both of the laborers and their works4444 ,the series of volumes must ever form a work of permanent interest on account of its exhibiting the progress of ,american science during the long period which it covers4 ,comparing #ahag with #ahdg1 we mark on this subject a very gratifying change4 ,the cultivators of science in the ,united ,states were then few--now they are numerous4 ,societies and associations of various names1 for the cultivation of natural history1 have been instituted in very many of our cities and towns1 and several of them have been active and efficient in making original observations and forming collections4 ,a summary follows presenting some facts as to the growth of scientific societies and scientific collections in this country during the period involved3 ,then the striking contrast between #ahah and #ahdg in the matter of organized effort toward scientific exploration is discussed1 as follows 7pp4 xvi et seq473 ,when we began our ,journal1 not one of the ,states had been surveyed in relation to its geology and natural history2 now those that have not been explored are few in number4 ,state collections and a ,united ,states ,museum hold forth many allurements to the young naturalist1 as well as to the archaeologist and the student of his own race4 ,the late ,exploring ,expedition ,wilkes with the ,national ,institute1 has enriched the capital with treasures rarely equalled in any country1 and the ,smithsonian ,institution recently organized at ,washington1 is about to begin its labors for the increase and diffusion of knowledge among men4 ,it must not be forgotten that the ,american ,association of ,geologists and ,naturalists--composed of individuals assembled from widely separate portions of the ,union--by the seven sessions which it has held1 and by its rich volume of reports1 has produced a concentration and harmony of effort which promise happy results1 especially as1 like the ,british ,association1 it visits different towns and cities in its annual progress4 ,astronomy now lifts its exploring tubes from the observatories of many of our institutions4 ,even the ,ohio1 which within the memory of the oldest living men1 rolled along its dark waters through interminable forests1 or received the stains of blood from deadly ,indian warfare1 now beholds on one of its most beautiful hills1 and near its splendid city1 a permanent observatory with a noble telescope sweeping the heavens1 by the hand of a zealous and gifted observer4 ,at ,washington also1 under the powerful patronage of the general government1 an excellent observatory has been established1 and is furnished with superior instruments1 under the direction of a vigilant and well instructed astronomer--seconded by able and zealous assistants4 ,here also 7in ,yale ,college7 successful observations have been made with good instruments1 although no permanent building has been erected for an ,observatory4 ,we only give single examples by way of illustration1 for the history of the progress of science in the ,united ,states1 and of institutions for its promotion1 during the present generation1 would demand a volume4 ,it is enough for our purpose that science is understood and valued1 and the right methods of prosecuting it are known1 and the time is at hand when its moral and intellectual use will be as obvious as its physical applications4 ,nor is it to be forgotten that we have awakened an ,european interest in our researches3 general science has been illustrated by treasures of facts drawn from this country1 and our discoveries are eagerly sought for and published abroad4 ,while with our co-workers in many parts of our broad land1 we rejoice in this auspicious change1 we are far from arrogating it to ourselves4 ,multiplied labors of many hands have produced the great results4 ,in the place which we have occupied1 we have persevered despite of all discouragements1 and may1 with our numerous coadjutors1 claim some share in the honors of the day4 ,we do not say that our work might not have been better done--but we may declare with truth that we have done all in our power1 and it is something to have excited many others to effort and to have chronicled their deeds in our annals4 ,let those that follow us labor with like zeal and perseverance1 and the good cause will continue to advance and prosper4 ,it is the cause of truth--science is only embodied and sympathized truth and in the beautiful conception of our noble ,agassiz--8it tells the thought of ,god40 ,the preface closes with some personal remarks3 ,in tracing back the associations of many gone-by years1 a host of thoughts rush in1 and pensive remembrance of the dead who have labored with us casts deep shadows into the vista through which we view the past4 ,anticipation of the hour of discharge1 when our summons shall arrive1 gives sobriety to thought and checks the confidence which health and continued power to act might naturally inspire1 were we not reproved1 almost every day1 by the death of some co-eval1 co-worker1 companion1 friend or patron4 ,this very hour is saddened by such an event1--but we will continue to labor on1 and strive to be found at our post of duty1 until there is nothing more for us to do2 trusting our hopes for a future life in the hands of ,him who placed us in the midst of the splendid garniture of this lower world1 and who has made not less ample provision for another and a better4 ,editorial and financial4--,the editorial labors on the ,journal were carried by the elder ,silliman alone for twenty years from #ahah to #ahch4 ,as has been clearly shown in his statements1 already quoted1 he was1 after the first beginning1 personally responsible also for the financial side of the enterprise4 ,with volume #cd 7#ahch7 the name of ,benjamin ,silliman1 ,jr41 is added as co-editor on the title page4 ,he was graduated from ,yale ,college the year preceding and at this date was only twenty-one years old4 ,his aid was unquestionably of much service from the beginning and increased rapidly with years and experience4 ,the elder ,silliman introduces him in the preface to vol4 #cd 7#ahch7 and comes back to the subject again in the preface to vol4 #ej 7#ahdg74 ,the whole editorial situation is here presented as follows3 8,during twenty years from the inception of this ,journal1 the editor labored alone1 although overtures for editorial cooperation had been made to him by gentlemen commanding his confidence and esteem1 and who would personally have been very acceptable4 ,it was1 however1 his opinion that the unity of purpose and action so essential to the success of such a work were best secured by individuality2 but he made every effort1 and not without success1 to conciliate the good will and to secure the assistance of gentlemen eminent in particular departments of knowledge4 ,on the title page of ,no4 #a1 vol4 #cd1 published in ,july1 #ahch1 a new name is introduced3 the individual to whom it belongs having been for several years more or less concerned in the management of the ,journal1 and from his education1 position1 pursuits and taste1 as well as from affinity1 being almost identified with the editor1 he seemed to be quite a natural ally1 and his adoption into the editorship was scarcely a violation of individual unity4 ,his assistance has proved to be very important3--his near relation to the senior editor prevents him from saying more1 while justice does not permit him to say less40 ,as is distinctly intimated in the preceding paragraph the elder ,silliman was fortunate in obtaining the assistance in his editorial labors of numerous gentlemen interested in the enterprise4 ,their cooperation provided many of the scientific notices1 book reviews and the like contained in the ,miscellany with which each number closed4 ,it is impossible1 at this date1 to render the credit due to ,silliman's helpers or even to mention them by name4 ,very early ,asa ,gray was one of these as occasional notes are signed by his initials4 ,dr4 ,levi ,ives of ,new ,haven was another4 ,prof4 ,j4 ,griscom of ,paris also sent numerous contributions even as early as #ahbe 7see #i1 #aed1 #ahbe2 #bb1 #aib1 #ahcb2 #bd1 #cdb1 #ahcc1 and others74 ,some statements have already been quoted from the early volumes as to the business part of ,silliman's enterprise4 ,the subject is taken up more fully in the preface to volume #ej 7#ahdg74 ,no one can fail to marvel at the energy and optimism required to push the ,journal forward when conditions must have been so difficult and encouragement so scanty4 ,he says 7pp4 iii1 iv73 ,this ,journal first appeared in ,july1 #ahah1 and in ,june1 #ahai1 the first volume of four numbers and #ddh pages was completed4 ,this scale of publication1 originally deemed sufficient1 was found inadequate to receive all the communications1 and as the receipts proved insufficient to sustain the expenses1 the work1 having but three hundred and fifty subscribers1 was1 at the end of the year1 abandoned by the publishers4 ,an unprofitable enterprise not being attractive to the trade1 ten months elapsed before another arrangement could be carried into effect1 and1 therefore1 ,no4 #a of vol4 #b was not published until ,april1 #ahbj4 ,the new arrangement was one of mutual responsibility for the expenses1 but the ,editor was constrained nevertheless to pledge his own personal credit to obtain from a bank the funds necessary to begin again1 and from this responsibility he was1 for a series of years1 seldom released4 ,the single volume per annum being found insufficient for the communications1 two volumes a year were afterward published1 commencing with the second volume4 ,the publishers whose names appear on the title page of the four numbers of the first volume are 8,j4 ,eastburn ,co41 ,literary ,rooms1 ,broadway1 ,new ,york0 and 8,howe ,spalding1 ,new ,haven40 ,for the second volume and those immediately following the corresponding statement 8printed and published by ,s4 ,converse ,new ,haven for the ,editor40 ,silliman adds 7p4 iv73 ,at the conclusion of vol4 #aj1 in ,february1 #ahbf1 the work was again left upon the hands of its ,editor2 all its receipts had been absorbed by the expenses1 and it became necessary now to pay a heavy sum to the retiring publisher1 as an equivalent for his copies of previous volumes1 as it was deemed necessary either to control the work entirely or to abandon it4 ,the ,editor was not willing to think of the latter1 especially as he was encouraged by public approbation1 and was cheered onward in his labors by eminent men both at home and abroad1 and he saw distinctly that the ,journal was rendering service not only to science and the arts1 but to the reputation of his country4 ,he reflected1 moreover1 that in almost every valuable enterprise perseverance in effort is necessary to success4 ,he being now sole proprietor1 a new arrangement was made for a single year1 the publishers being at liberty1 at the end of that time1 to retire1 and the ,editor to resume the ,journal should he prefer that course4 ,the latter alternative he adopted1 taking upon himself the entire concern1 including both the business and the editorial duties1 and of course1 all the correspondence and accounts4 ,from that time the work has proceeded without interruption1 two volumes per annum having been published for the last twenty years2 and its pecuniary claims ceased to be onerous1 although its means have never been large4444 ,later in the same preface he adds 7p4 xiv73 ,it may be interesting to our readers to know something of the patronage of the ,journal4 ,it has never reached one thousand paying subscribers1 and has rarely exceeded seven or eight hundred--for many years it fluctuated between six and seven hundred4 ,it has been far from paying a reasonable editorial compensation2 often it has paid nothing1 and at present it does little more than pay its bills4 ,the number of engravings and the extra labor in printer's composition1 cause it to be an expensive work1 while its patronage is limited4 ,it is difficult at this date to give any adequate statement of the amount of encouragement and active assistance given to ,silliman by his scientific colleagues in ,new ,haven and elsewhere--a subject earlier alluded to4 ,it is fortunately possible1 however1 to acknowledge the generous aid received by the ,journal in the early days from a source near at hand4 ,it has already been noted in another place that the dawning activity of science at ,new ,haven was recognized by the founding of the 8,connecticut ,academy of ,arts and ,sciences10 formally established at ,new ,haven in #agii and the third scientific body to be organized in this country4 ,from the beginning of the ,journal in #ahah1 the ,connecticut ,academy freely gave its support both in papers for publication and at least on one occasion later it gave important financial aid4 ,upon the occasion of the celebration of the centennial anniversary of the ,academy on ,october #aa1 #ahii1 ,professor1 later ,governor1 ,baldwin1 the president of the ,academy1 discusses this subject in some detail4 ,he says in part3 ,to support his ,silliman's undertaking1 a vote had been passed in ,february #ahah1 8that the ,committee of ,publication may allow such of the ,academy's papers as they think proper1 to be published in ,mr4 ,silliman's ,scientific ,journal40 ,free use was made of this authority1 and a large part of the contents of the ,journal was for many years drawn from this source4 ,in some cases this fact was noted in publication2#b but in most it was not4444 ,in #ahbf1 when the ,journal was in great need of financial support1 the ,academy further voted to pay for a year the cost of printing such of its papers as might be published in it4 ,in ,baldwin's ,annals of ,yale ,college1 published in #ahca1 it is described as a publication 8honorable to the science of our common country10 and having 8an additional value as being adopted as the acknowledged organ of the ,connecticut ,academy of ,arts and ,sciences40 ,many active campaigns were carried on over the country through paid agents to obtain new subscribers for the ,journal and it was doubtless due to these efforts that the nominal subscription list was1 at times1 as already noted1 relatively large as compared with that of a later date4 ,the new subscribers in many cases1 however1 did not remain permanently interested1 often failed to pay their bills1 and the uncertain and varying demand upon the supply of printed copies was doubtless one reason why many single numbers became early out of print4 ,an interesting sidelight is thrown upon the efforts of ,silliman to interest the public in his work1 at its beginning1 by a letter to the editor from ,thomas ,jefferson1 then seventy-five years of age4 ,the writer is indebted to ,mr4 ,robert ,b4 ,adam of ,buffalo for a copy of this letter and its interest justifies its being reproduced here entire4 ,the letter is as follows3 ,monticello1 ,apr4 #aa4 '#ah4 ,sir ,the unlucky displacement of your letter of ,mar #c has been the cause of delay in my answer4 altho' ,i have very generally withdrawn from subscribing to or reading periodical publications from the love of rest which age produces1 yet ,i willingly subscribe to the journal you propose from a confidence that the talent with which it will be edited will entitle it to attention among the things of select reading for which alone ,i have time now left4 be so good as to send it by mail1 and the receipt of the #ast number will be considered as announcing that the work is commenced and the subscription money for a year shall be forwarded4 ,accept the assurance of my great esteem and respect4 ,th4 ,jefferson ,professor ,silliman4 ,contributors4--,an interesting summary is also given by ,silliman of the contributors to the ,journal and the extent of their work 7vol4 #ej1 pp4 xii1 xiii72 he says3 ,we find that there have been about #fjj contributors of original matter to the ,journal1 and we have the unexpected satisfaction of believing that probably five-sixths of them are still living2 for we are not certain that more than fifty are among the dead2 of perhaps fifty more we are without information1 and if that additional number is to be enrolled among the 8stelligeri10 we have still #ejj remaining4 ,among them are not a few of the veterans with whom we began our career1 and several of these are still active contributors4 ,shall we then conclude that the peaceful pursuits of knowledge are favorable to long life8 ,this we think is1 cteris paribus1 certainly true3 but in the present instance1 another reason can be assigned for the large amount of survivorship4 ,as the ,journal has advanced and death has removed its scientific contributors1 younger men and men still younger1 have recruited the ranks1 and volunteers have enlisted in numbers constantly increasing1 so that the flower of the host are now in the morning and meridian of life4 ,we have been constantly advancing1 like a traveller from the equinoctial towards the colder zones1--as we have increased our latitude1 stars have set and new stars have risen1 while a few planetary orbs visible in every zone1 have continued to cheer us on our course4 ,the number of articles1 almost exclusively original1 contained in the ,journal is about #ahjj1 and the ,index will show how many have been contributed by each individual2 we have doubtless included in this number some few articles republished from foreign ,journals--but we think they are even more than counterbalanced by original communications without a name and by editorial articles1 both of which have been generally omitted in the enumeration4 ,of smaller articles and notices in the ,miscellany1 we have not made any enumeration1 but they evidently are more numerous than the regular articles1 and we presume that they may amount to at least #bejj4 ,of party1 either in politics or religion1 there is no trace in our work2 of personalities there are none1 except those that relate to priority of claims or other rights of individuals4 ,of these vindications the number is not great1 and we could heartily have wished that there had been no occasion for any4 ,general ,scope of ,articles4--,many references will be found in the chapters following which throw light upon the character and scope of the papers published in the ,journal1 particularly in its early years2 a few additional statements here may1 however1 prove of interest4 ,one feature that is especially noticeable is the frequent publication of articles planned to place before the readers of the ,journal in full detail subjects to which they might not otherwise have access4 ,these are sometimes translations2 sometimes republications of articles that had already appeared in ,english periodicals2 again1 they are exhaustive and critical reviews of important memoirs or books4 ,the value of this feature in the early history of the ,journal1 when the distribution of scientific literature had nothing of the thoroughness characteristic of recent years1 is sufficiently obvious4 ,it is also interesting to note the long articles of geological description and others giving lists of mineral or botanical localities4 ,noteworthy1 too1 is the attempt to keep abreast of occurring phenomena as in the many notes on tornadoes and storms by ,redfield1 ,loomis1 etc42 on auroras at different localities2 on shooting stars by ,herrick1 ,olmstead and others4 ,the wide range of topics treated of is quite in accordance with the plan of the editor as given on an earlier page4 ,some notes1 taken more or less at random1 may serve to illustrate this point4 ,an extended and quite technical discussion of 8,musical ,temperament0 opens the first number 7#a1 pp4 #i-ce7 and is concluded in the same volume 7pp4 #agf-aii74 ,an article on 8,mystery0 is given by ,mark ,hopkins1 ,a4,m41 8late a tutor of ,williams ,college0 7#ac1 #bag1 #ahbh74 ,there is an essay on 8,gypsies0 by ,j4 ,griscom 7from the ,revue ,encyclopdique7 in volume #bd 7pp4 #cdb-cde1 #ahcc71 while some notes on ,american gypsies are added in vol4 #bf 7p4 #ahi1 #ahcd74 ,the 8divining rod0 is described at length in vol4 #aa 7pp4 #bja-bab1 #ahbf71 but without giving any comfort to the credulous2 on the contrary the last paragraph states that 8the pretensions of diviners are worthless1 etc40 ,a long article by ,j4 ,finch on the forts of ,boston harbour appeared in #ahbd 7#h1 #cch-cdh72 the concluding paragraph seems worthy of quotation3 8,many centuries hence1 if despotism without1 or anarchy within1 should cause the republican institutions of ,america to fade1 then these fortresses ought to be destroyed1 because they would be a constant reproach to the people2 but until that period1 they should be preserved as the noblest monuments of liberty40 ,the promise to include the fine arts is kept by the publication of various papers1 as of the ,trumbull paintings 7#af1 #afc1 #ahbi72 also by a series of articles on 8architecture in the ,united ,states0 7#ag1 #ii1 #ahcj2 #ah1 #bah1 #bbj1 #ahcj7 and others4 ,quite in another line is the paper by ,j4 ,w4 ,gibbs 7#cc1 #cbd1 #ahch7 on 8,arabic words in ,english40 ,a number of related linguistic papers by the same author are to be found in other volumes4 ,papers in pure mathematics are also not infrequent1 though now not considered as falling within the field of the ,journal4 ,applied science takes a prominent place through all the volume of the ,first ,series4 ,an interesting paper is that on ,eli ,whitney1 containing an account of the cotton gin2 this is accompanied by an excellent portrait 7#ba1 #bja-bfd1 #ahcb74 ,the steam engine and its application are repeatedly discussed and in the early volumes brief accounts are given of the early steamboats in use2 for example1 between ,stockholm and ,st4 ,petersburg 7#b1 #cdg1 #ahbj72 ,trieste and ,venice 7#d1 #cgg1 #ahbb72 on the ,swiss ,lakes 7#f1 #che1 #ahbc74 ,the voyage of the first ,atlantic steamboat1 the 8,savannah10 which crossed from ,savannah to ,liverpool in #ahai1 is described 7#ch1 #aee1 #ahdj72 mention is also made of the 8first iron boat0 7#c1 #cga1 #ahba2 #e1 #cif1 #ahbb74 ,a number of interesting letters on 8,steam ,navigation0 are given in vol4 #ce1 #afj1 #afb1 #ccb1 #ccc1 #ccf2 some of the suggestions seem very quaint1 viewed in the light of the experience of to-day4 ,a very early form of explosive engine is described at length by ,samuel ,morey 7#aa1 #ajd1 #ahbf72 this is an article that deserves mention in these days of gasolene motors4 ,even more interesting is the description by ,charles ,griswold 7#b1 #id1 #ahbj7 of the first submarine invented by ,david ,bushnell and used in the ,revolutionary ,war in ,august1 #aggf4 ,an account is also given of a dirigible balloon that may be fairly regarded as the original ancestor of the ,zeppelin 7see #aa1 #cdf1 #ahbf74 ,the whole subject of arial navigation is treated at length by ,h4 ,strait 7#be1 pp4 #be1 #bf1 #ahcd7 and the expression of his hopes for the future deserve quotation3 8,conveyance by air can be easily rendered as safe as by water or land1 and more cheap and speedy1 while the universal and uniform diffusion of the air over every portion of the earth1 will render arial navigation preferable to any other4 ,to carry it into effect1 there needs only an immediate appeal on a sufficiently large scale1 to experiment2 reason has done her part1 when experiment does hers1 nature will not refuse to sanction the whole4 ,arial navigation will present the works of nature in all their charms2 to commerce and the diffusion of knowledge1 it will bring the most efficient aid1 and it can thus be rendered serviceable to the whole human family40 ,a subject of quite another character is the first discussion of the properties of chloroform 7chloric ether7 and its use as an ansthetic 7,guthrie1 #ba1 #fd1 #dje1 #ahcb2 #bb1 #aje1 #ahcb2 ,levi ,ives1 #ba1 #djf74 ,further interesting communications are given of the first analyses of the gastric juice and the part played by it in the process of digestion4 ,dr4 ,william ,beaumont of ,st4 ,louis took advantage of a patient who through a gun-shot wound was left with a permanent opening into his stomach through which the gastric juice could be drawn off4 ,the results of ,dr4 ,beaumont and of ,professor ,robley ,dunglison1 to whom samples were submitted1 are given in full in the life of ,beaumont by ,jesse ,s4 ,myer 7,st4 ,louis1 #aiab74 ,the interest of the matter1 so far as the ,journal is concerned1 is chiefly because ,dr4 ,beaumont selected ,professor ,silliman as a chemist to whom samples for examination were also submitted4 ,an account of ,silliman's results is given in the ,beaumont volume referred to 7see also #bf1 #aic1 #ahcd74 ,desiring the support of a chemist of wider experience in organic analysis1 he also sent a sample through the ,swedish consul to ,berzelius in ,stockholm4 ,after some months the sample was received and it is interesting to note in a perfectly fresh condition2 it is to be regretted1 however1 that the ,swedish chemist failed to add anything to the results already obtained in this country 7#bg1 #dj;b1 #ahce74 ,the above list1 which might be greatly extended1 seems to leave little ground for the implied criticism replied to by ,silliman as follows 7#af1 p4 v1 #ahbi73 ,a celebrated scholar1 while himself an editor1 advised me1 in a letter1 to introduce into this ,journal as much 8readable0 matter as possible3 and there was1 pretty early1 an earnest but respectful recommendation in a ,philadelphia paper1 that ,literature1 in imitation of the ,london ,quarterly ,journal of ,science1 c4 should be in form1 inscribed among the titles of the work4 ,the ,second1 ,third and ,fourth ,series4 ,the ,,second ,,series of the ,journal1 as already stated1 began with ,january1 #ahdf4 ,up to this time the publication had been a quarterly or two volumes annually of two numbers each4 ,from #ahdf until the completion of an additional fifty volumes in #ahga1 the ,journal was made a bimonthly1 each of the two yearly volumes having three numbers each4 ,furthermore1 a general index was given for each period of five years1 that is for every ten volumes4 ,illustration3 ,edward ,s4 ,dana ,much more important than this change was the addition to the editorial staff of ,james ,dwight ,dana1 ,silliman's son-in-law4 ,dana returned from the four-years cruise of the ,wilkes ,exploring ,expedition in #ahdb2 he settled in ,new ,haven1 was married in #ahdd1 and in #ahej was appointed ,silliman professor of ,geology in ,yale ,college4 ,he was at this time actively engaged in writing his three quarto reports for the ,expedition and hence did not begin his active professional duties in ,yale ,college until #ahef4 ,part of his inaugural address was quoted on an earlier page4 ,dana had already performed the severe labor of preparing the complete index to the ,first ,series1 a volume of about #cej pages1 finally issued in #ahdg4 ,from the beginning of the ,second ,series he was closely associated with his brother-in-law1 the younger ,silliman4 ,later the editorial labor devolved more and more upon him and the larger part of this he carried until about #ahij4 ,his work1 was1 however1 somewhat interrupted during periods of ill health4 ,this was conspicuously true during a year's absence in ,europe in #ahei-fj1 made necessary in the search for health2 during these periods the editorial responsibility rested entirely upon the younger ,silliman4 ,of ,dana's contributions to science in general this is not the place to speak1 nor is the present writer the one to dwell in detail upon his work for the ,journal4 ,this subject is to such an extent involved in the history of geology and zoology1 the subjects of several succeeding chapters1 that it is adequately presented in them4 ,it may1 however1 be worth stating that in the bibliography accompanying the obituary notice of ,dana 7#di1 #cbi-cef1 #ahie7 some #bej titles of articles in the ,journal are enumerated2 these aggregate approximately #bhjj pages4 ,the number of critical notes1 abstracts1 book reviews1 etc41 could be also given1 were it worth while1 but what is much more significant in this connection1 than their number or aggregate length1 is the fact that these notices are in a large number of cases--like those of ,gray in botany--minutely critical and original in matter4 ,they thus give the writer's own opinion on a multitude of different subjects4 ,it was a great benefit to ,dana1 as it was to science also1 that he had this prompt means at hand of putting before the public the results of his active brain1 which continued to work unceasingly even in times of health prostration4 ,this may be the most convenient place to add that as ,dana became gradually less able to carry the burden of the details involved in editing the ,journal in addition to his more important scientific labors1 particularly from #ahij on1 this work devolved more and more upon his son1 the present editor1 whose name was added to the editorial staff in #ahge1 with volume #i1 of the ,third ,series4 ,the latter has served continuously until the present time1 with the exception of absences1 due to ill health1 in #ahic-id and in #aijc2 during the first of these ,professor ,henry ,s4 ,williams and during the second ,professor ,h4 ,e4 ,gregory occupied the editorial chair4 ,the ,,third ,,series began in #ahga1 after the completion of the one-hundredth volume from the beginning in #ahah4 ,at this date the ,journal was made a monthly and as such it remains to-day4 ,fifty volumes again completed this series1 which closed in #ahie4 ,the ,,fourth ,,series began with ,january1 #ahif1 and the present number for ,july1 #aiah1 is the opening one of the forty-sixth volume or1 in other words1--the one hundred and ninety-sixth volume of the entire issue since #ahah4 ,the ,fourth ,series1 according to the precedent established1 will end with #aibj4 ,associate ,editors4--,in #ahea the new policy was introduced of adding 8,associate ,editors0 to the staff4 ,the first of these was ,dr4 ,wolcott ,gibbs of ,cambridge4 ,he began his duties with the eleventh volume of the ,second ,series in #ahea and continued them with unceasing care and thoroughness for more than twenty years4 ,in a note dated ,jan4 #a1 #ahea 7#aa1 #aje71 he says3 ,it is my intention in future to prepare for the columns of this ,journal abstracts of the more important physical and chemical memoirs contained in foreign scientific journals1 accompanied by references1 and by such critical observations as the occasion may demand4 ,contributions of a similar character from others will of course not be excluded by this arrangement1 but ,i shall hold myself responsible only for those notices which appear over my initials4 ,the departments covered by ,dr4 ,gibbs1 in his excellent monthly contributions1 embraced chemistry and physics1 and these subjects were carried together until #ahgc when they were separated and the physical notes were furnished1 first by ,alfred ,m4 ,mayer and later successively by ,e4 ,c4 ,pickering 7from #ahgd71 ,j4 ,p4 ,cooke 7from #ahgg71 and ,john ,trowbridge 7from #ahhj74 ,the first instalment of the long series of notes in chemistry and chemical physics by ,george ,f4 ,barker was printed in volume #ej1 #ahgj4 ,he came in at first to occasionally relieve ,dr4 ,gibbs1 but soon took the entire responsibility4 ,his name was placed among the associate editors on the cover in #ahgg and two years later ,dr4 ,gibbs formally retired4 ,it may be added that from the beginning in #ahea to the present time1 the notes in 8,chemistry and ,physics0 have been continued almost without interruption4 ,the other departments of science have been also fully represented in the notes1 abstracts of papers published1 book notices1 etc41 of the successive numbers1 but as with the chemistry and physics the subject of botany was long treated in a similar formal manner4 ,for the notes in this department1 the ,journal was for many years indebted to ,dr4 ,asa ,gray1 who became associate editor in #ahec1 two years after ,gibbs1 although he had been a not infrequent contributor for many years previously4 ,gray's contributions were furnished with great regularity and were always critical and original in matter4 ,they formed indeed one of the most valuable features of the ,journal for many years2 as botanists well appreciate1 and1 as ,professor ,goodale has emphasized in his chapter on botany1 ,gray's notes are of vital importance in the history of the development of his subject4 ,with ,gray's retirement from active duty1 his colleague1 ,george ,w4 ,goodale1 took up the work in #ahhh and in #ahie ,william ,g4 ,farlow1 also of ,cambridge1 was added as an associate editor in cryptogamic botany4 ,at this time1 however1 and indeed earlier1 the sphere of the ,journal had unavoidably contracted and botany perforce ceased to occupy the prominent place it had long done in the ,journal pages4 ,this is not the place to present an appreciation of the truly magnificent work of ,asa ,gray4 ,it may not be out of place1 however1 to call attention to the notice of ,gray written for the ,journal by his life-long friend1 ,james ,d4 ,dana 7#ce1 #aha1 #ahhh74 ,the opening paragraph is as follows3 8,our friend and associate1 ,asa ,gray1 the eminent botanist of ,america1 the broad-minded student of nature1 ended his life of unceasing and fruitful work on the #cjth of ,january last4 ,for thirty-five years he has been one of the editors of this ,journal1 and for more than fifty years one of its contributors2 and through all his communications there is seen the profound and always delighted student1 the accomplished writer1 the just and genial critic1 and as ,darwin has well said1 #8,the lovable man4'0 ,the third associate editor1 following ,gray1 was ,louis ,agassiz1 whose work for science1 particularly in his adopted home in this country1 calls for no praise here4 ,his term of service extended from #ahec to #ahff and1 particularly in the earlier years1 his contributions were numerous and important4 ,the next gentleman in the list was ,waldo ,i4 ,burnett1 of ,boston1 who served one year only1 and then followed four of ,dana's colleagues in ,new ,haven1 of whose generosity and able assistance it would be impossible to say too much4 ,these gentlemen were ,brush in mineralogy2 ,johnson in chemistry1 particularly on the agricultural side2 ,newton in mathematics and astronomy1 whose contributions will be spoken of elsewhere2 and ,verrill--a student of ,agassiz--in zoology4 ,all of these gentlemen1 besides their frequent and important original articles1 were ever ready not only to give needed advice1 but also1 to furnish brief communications1 abstracts of papers and book reviews1 and otherwise to aid in the work4 ,verrill particularly furnished the ,journal a long list of original and important papers1 chiefly in systematic zoology1 extending from #ahfe almost down to the present year4 ,his abstracts and book notices also were numerous and trenchant and it is not too much to say that without him the ,journal never could have filled the place in zoology which it so long held4 ,much later the list of ,new ,haven men was increased by the addition of ,henry ,s4 ,williams 7#ahid71 and ,o4 ,c4 ,marsh 7#ahie74 ,illustration3 ,wolcott ,gibbs ,of the valuable work of those more or less closely associated in the conduct of the ,journal at the present time1 it would not be appropriate to speak in detail4 ,it must suffice to say that the services rendered freely by them have been invaluable1 and to their aid is due a large part of the success of the ,journal1 especially since the ,fourth ,series began in #ahif4 ,but even this statement is inadequate1 for the editor-in-chief has had the generous assistance of other gentlemen1 whose names have not been placed on the title page1 and who have also played an important part in the conduct of the ,journal4 ,this policy1 indeed1 is not a matter of recent date4 ,very early in the ,first ,series1 ,professor ,griscom of ,paris1 as already noted1 furnished notes of interesting scientific discoveries abroad4 ,other gentlemen have from time to time acted in the same capacity4 ,the most prominent of them was ,professor ,jerome ,nickls of ,nancy1 ,france1 who regularly furnished a series of valuable notes on varied subjects1 chiefly from foreign sources1 extending from #aheb to #ahfi4 ,on the latter date he met an untimely death in his laboratory in connection with experiments upon hydrofluoric acid 7#dg1 #dcd1 #ahfi74 ,it may be added1 further1 that one of the striking features about the ,journal1 especially in the earlier half century of its existence1 is the personal nature of many of its contributions1 which were very frequently in the form of letters written to ,benjamin ,silliman or ,j4 ,d4 ,dana4 ,this is perhaps but another reflection of the extent to which the growth of the magazine centered around these two men1 whose wide acquaintance and broad scientific repute made of the ,journal a natural place to record the new and interesting things that were being discovered in science4 ,the following list gives the names and dates of service1 as recorded on the ,journal title pages1 of the gentlemen formally made ,associate ,editors3 ,wolcott ,gibbs 7#b7 #aa1 #ahea to 7#c7 #ah1 #ahgi ,asa ,gray #ae1 #ahec #cd1 #ahhg ,louis ,agassiz #af1 #ahec 7#b7 #da1 #ahff ,waldo ,i4 ,burnett #af1 #ahec #ag1 #ahec ,george ,j4 ,brush #ce1 #ahfc 7#c7 #ah1 #ahgi ,samuel ,w4 ,johnson #ce1 #ahfc #ah1 #ahgi ,hubert ,a4 ,newton 7#b7 #ch1 #ahfd to 7#d7 #a1 #ahif ,addison ,e4 ,verrill #dg1 #ahfi ,alfred ,m4 ,mayer 7#c7 #e1 #ahgc to 7#c7 #f1 #ahgc ,edward ,c4 ,pickering #g1 #ahgd #ac1 #ahgg ,george ,f4 ,barker #ad1 #ahgg 7#d7 #bi1 #aiaj ,josiah ,p4 ,cooke #ad1 #ahgg 7#c7 #dg1 #ahid ,john ,trowbridge 7#c7 #ai1 #ahhj ,george ,w4 ,goodale #ce1 #ahhh ,henry ,s4 ,williams #dg1 #ahid ,henry ,p4 ,bowditch #di1 #ahie to 7#d7 #h1 #ahii ,william ,g4 ,farlow #di1 #ahie ,othniel ,c4 ,marsh #di1 #ahie to 7#d7 #f1 #ahii ,henry ,a4 ,rowland 7#d7 #a1 #ahif #aj1 #aijj ,joseph ,s4 ,diller #a1 #ahif ,louis ,v4 ,pirsson #g1 #ahii ,william ,m4 ,davis #i1 #aijj ,joseph ,s4 ,ames #ab1 #aija ,horace ,l4 ,wells #ah1 #aijd ,herbert ,e4 ,gregory #ah1 #aijd ,horace ,s4 ,uhler #cc1 #aiab ,present and ,future ,conditions4 ,the field to be occupied by the 8,american ,journal of ,science and ,arts10 as seen by its founder in #ahah and presented by him in the first number1 as quoted entire on an earlier page1 was as broad as the entire sphere of science itself4 ,it thus included all the departments of both pure and applied science and extended even to music and fine arts also4 ,as the years went by1 however1 and the practical applications of science greatly increased1 technical journals started up1 and the necessity of cultivating this constantly expanding field diminished4 ,it was not1 however1 until ,january1 #ahhj1 that 8the ,arts0 ceased to be a part of the name by which the ,journal was known4 ,about the same date also--or better a little earlier--began an increasing development of scientific research1 particularly as fostered by the graduate schools of our prominent universities4 ,the full presentation of this subject would require much space and is indeed unnecessary as the main facts must be distinct in the mind of the reader4 ,it is only right1 however1 that the large part played in this movement by the ,johns ,hopkins ,university 7founded in #ahgf7 should be mentioned here4 ,as a result of this movement1 which has been of great benefit in stimulating the growth of science in the country1 many new journals of specialized character have come into existence from time to time4 ,further localization and specialization of scientific publication have resulted from the increased activity of scientific societies and academies at numerous centers and the springing into existence thereby of new organs of publication through them1 as also through certain of the ,government ,departments1 the ,carnegie ,institution1 and certain universities and museums4 ,as bearing upon this subject1 the following list of the more prominent scientific periodicals started in this country since #ahfg is not without interest3 #ahfg- 4 ,american ,naturalist4 #ahge- 4 ,botanical ,bulletin2 later ,botanical ,gazette4 #ahgi-aiac4 ,american ,chemical ,journal4 #ahhj-aiae4 ,school of ,mines ,quarterly4 #ahhc- 4 ,science4 #ahhe- 4 ,journal of ,heredity4 #ahhg- 4 ,journal of ,morphology4 #ahhg-aijh4 ,technology ,quarterly4 #ahhh-aije4 ,american ,geologist4 #ahia- 4 ,journal of ,comparative ,neurology4 #ahic- 4 ,journal of ,geology4 #ahic- 4 ,physical ,review4 #ahie- 4 ,astrophysical ,journal4 #ahif- 4 ,journal of ,physical ,chemistry4 #ahif- 4 ,terrestrial ,magnetism4 #ahig-ahii4 ,zoological ,bulletin2 followed by #aijj- 4 ,biological ,bulletin4 #aija- 4 ,american ,journal of ,anatomy4 #aijd- 4 ,journal of ,experimental ,zoology4 #aije- 4 ,economic ,geology4 #aijf- 4 ,anatomical ,record4 #aijg- 4 ,journal of ,economic ,entomology4 #aiaa- 4 ,journal of ,animal ,behavior4 #aiad- 4 ,american ,journal of ,botany4 #aiaf- 4 ,genetics4 #aiah- 4 ,american ,journal of ,physical ,anthropology4 ,the result of the whole movement has been of necessity to narrow1 little by little1 the sphere of a general scientific periodical such as the ,journal has been from the beginning4 ,the exact change might be studied in detail by tabulating as to subjects the contents of successive volumes1 decade by decade1 from #ahgj down4 ,it is sufficient1 here1 however1 to recognize the general fact that while the number of original papers published in the periodicals of this country1 in #aiaj1 for example1 was very many times what it was in #ahbe1 a large part of these have naturally found their home in periodicals devoted to the special subject dealt with in each case4 ,that this movement will continue1 though in lessened degree now that the immediate demand is measurably satisfied1 is to be expected4 ,at the same time it has not seemed wise1 at any time in the past1 to formally restrict the pages of the ,journal to any single group of subjects4 ,the future is before us and its problems will be met as they arise4 ,at the moment1 however1 there seems to be still a place for a scientific monthly sufficiently broad to include original papers of important general bearing even if special in immediate subject4 ,in this way it would seem that 8,silliman's ,journal0 can best continue to meet the ideals of its honored founder1 modified as they must be to meet the change of conditions which a century of scientific investigation and growth have wrought4 ,incidentally it is not out of place to add that a self-supporting1 non-subsidized scientific periodical may hope to find a larger number of subscribers from among the workers in science and the libraries if it is not too restricted in scope4 ,the last subject touched upon introduces the essential matter of financial support without which no monthly publication can survive4 ,with respect to the periodicals of recent birth1 listed above1 it is safe to say that some form of substantial support or subsidy--often very generous--is the rule1 perhaps the universal one4 ,this has never been the case with the ,american ,journal4 ,the liberality and broad-minded attitude of ,yale ,college in the early days1 and of the ,yale ,university that has developed from it1 have never been questioned4 ,at the same time the special conditions have been such as to make it desirable that the responsibility of meeting the financial requirements should be carried by the editors-in-chief4 ,at present the ,yale ,library gives adequate payment for certain publications received by the ,journal in exchange1 though for many years they were given to it as a matter of course1 free of charge4 ,beyond this there is nothing approaching a subsidy4 ,the difficulties on the financial side met with by the elder ,silliman have been suggested1 although not adequately presented1 in the various statements quoted from early volumes4 ,the same problems in varying degree have continued for the past sixty years4 ,since #aiad they have been seriously aggravated for reasons that need not be enlarged upon4 ,prior to that date the subscription list had1 for reasons chiefly involved in the development of special journals1 been much smaller than the number estimated by ,silliman1 for example1 in volume #ej 7p4 xiv71 although there has been this partial compensation that the considerable number of well-established libraries on the subscription list has meant a greater degree of stability and a smaller proportion of bad accounts4 ,the past four years1 however1 the ,journal1 with all similar undertakings here and elsewhere1 has been compelled to bear its share of the burden of the world war in diminished receipts and greatly increased expenses4 ,it is gratifying to be able to acknowledge here the generosity of the authors1 or of the laboratories with which they have been connected1 in their willingness not infrequently to give assistance1 for example1 in the payment of more or less of the cost of engravings1 or in a few special cases a large portion of the total cost of publication4 ,in this way the problem of ways and means1 constantly before the editor who bears the sole responsibility1 has been simplified4 ,it should also be stated that as those immediately interested have looked forward to the present anniversary1 it has been with the hope that this occasion might be an appropriate one for the establishment of a 8,silliman ,fund0 to commemorate the life and work of ,benjamin ,silliman4 ,the income of such a fund would lift from the ,university the burden that must unavoidably fall upon it when the responsibility for the conduct of the ,journal can no longer be carried by members of the family including the editor and--as in years long past--a silent partner whose aid on the business side has been essential to the efficiency and economy of the enterprise4 ,present conditions are not favorable for such a movement1 although something has been already accomplished in the desired direction4 ,at the present time every patriotic citizen must feel it his first duty to give his savings as well as his spare income to the support of the ,national ,government in the world struggle for freedom in which it is taking part4 ,but1 whatever the exact condition of the future may be1 it cannot be questioned that the ,journal founded by ,benjamin ,silliman in #ahah will survive and will continue to play a vital part in the support and further development of science4 ,the present year of #aiah finds the world at large1 and with it the world of science1 painfully crushed beneath the overwhelming weight of a world war of unprecedented severity4 ,the four terrible years now nearly finished have seen a fearful destruction of life and property which must have a sad influence on the progress of science for many years to come4 ,only in certain restricted lines has there been a partial compensation in the stimulating influence due to the immediate necessities connected with the great conflict4 ,one hundred years ago 8the reign of war0 was keenly in the mind of the editor in beginning his work1 but for him1 happily1 the long period of the ,napoleonic wars was already in the past1 as also the brief conflict of #ahab1 in which this country was engaged and in which ,silliman himself played a minor part4 ,we1 too1 must believe1 no matter how serious the outlook of the present moment1 that a fundamental change will come in the not distant future2 the nations of the world must sooner or later turn once more to peaceful pursuits and the scientific men of different races must become again not enemies but brothers engaged in the common cause of uplifting human life4 ,the peace that we look forward to to-day is not for this country alone1 but a peace which shall be a permanent blessing to the entire world for ages to come4 ,,note4--,the portrait which forms the frontispiece of this volume has been reproduced from the plate in volume #ej 7#ahdg74 ,the original painting was made by ,h4 ,willard in #ahce1 when ,silliman was in ,boston engaged in delivering the ,lowell lectures2 he was then nearly fifty-six years of age4 ,the engraving1 as he states elsewhere1 was made from this painting for the ,yale ,literary ,magazine1 and was published in the number for ,december1 #ahci4 ,it is interesting to quote the remarks with which the editor introduces the portrait 7#ej1 xviii1 #ahdg74 ,he says3 ,the portrait prefixed to this volume was engraved for a very different purpose and for others than the patrons of this ,journal4 ,it has been suggested by friends1 whose judgment we are accustomed to respect1 that it ought to find a place here1 since it is regarded as an authentic1 although1 perhaps1 a rather austere resemblance4 ,in yielding to this suggestion1 it may be sufficient to quote the sentiment of ,cowper on a similar occasion1 who remarked--8that after a man has1 for many years1 turned his mind inside out before the world1 it is only affectation to attempt to hide his face40 ,notes4 ,footnote #a3 ,the statements given are necessarily much condensed1 without an attempt to follow all changes of title2 furthermore1 the dates of actual publication for the academies given above are often somewhat vaguely recorded4 ,for fuller information see ,scudder's 8,catalogue of ,scientific ,serials1 #afcc-ahgf10 ,cambridge1 #ahgf2 also ,h4 ,carrington ,bolton's 8,catalogue of ,scientific and ,technical ,periodicals1 #affe-ahhb0 7,smithsonian ,institution1 #ahhe74 ,the writer is much indebted to ,mr4 ,c4 ,j4 ,barr1 ,assistant ,librarian of ,yale ,university ,library1 for his valuable assistance in this connection4 ,footnote #b3 ,the following footnote accompanies the opening article of the first volume of the ,journal4 8,from the ,,ms4 papers of the ,connecticut ,academy1 now published by permission40 ,similar notes appear elsewhere4 ,ed4 ,,ii ,a ,,century ,,of ,,geology4--,,the ,,progress ,,of ,,historical ,,geology ,,in ,,north ,,america ,by ,,charles ,,schuchert ,introduction4 ,the ,american ,journal of ,science1 8one of the greatest influences in ,american geology10 founded in #ahah1 has published a little more than #ib1jjj pages of scientific matter4 ,of geology1 including mineralogy1 there appear to be upward of #bj1jjj pages4 ,what a vast treasure house of geologic knowledge is stored in these #aid volumes1 and how well the editors have lived up to their proposed 8plan of work0 as stated in the opening volume1 where ,silliman says3 8,it is designed as a deposit for original ,american communications0 in 8the physical sciences 444 and especially our mineralogy and geology0 7#a1 v1 #ahah76 ,not only is it the oldest continuously published scientific journal of this country1 but it has proved itself to be 8perhaps the most important geological periodical in ,america0 7,merrill74 ,it is impossible to adequately present in this memorial volume of the ,journal the contents of the articles on the geological sciences4 ,editor ,silliman was not only the founder of the ,journal1 but the generating center for the making of geologists and promoting geology during the rise of this science in ,america4 ,for nearly three decades1 the workers came to him for counsel and help1 and he had a kind paternal word for them all4 ,this influence is also shown in the many letters which were addressed to him1 and which he published in the ,journal4 ,a similar influence1 paternal care1 and constructive criticism were continued by ,james ,d4 ,dana1 and especially in his earlier career as editor4 ,not including mineralogy1 there are in the ,journal upward of #aejj distinct articles on geology4 ,of these1 over #djj are on vertebrate paleontology1 about #cbe on invertebrate paleontology1 and #ij on paleobotany4 ,of articles bearing on historical geology there are about #afj1 and on stratigraphic geology more than #cfj4 ,in addition to all this1 there are more than #bjjj pages of geologic matter relating to books and of letters communicated to the editors ,silliman and ,dana4 ,we may summarize with ,doctor ,merrill's statement in his well-known ,contributions to the ,history of ,american ,geology3 8,from its earliest inception geological notes and papers occupied a prominent place in its pages1 and a perusal of the numbers from the date of issue down to the present time will1 alone1 afford a fair idea of the gradual progress of ,american geology40 ,before presenting a synopsis of the more important steps in the progress of historical geology in ,america1 it will be well to introduce a rapid survey of the rise of geology in ,europe1 for1 after all1 ,american geology grew out of that of ,england1 ,france and ,germany4 ,this dependence was conspicuously true during the first four decades of the previous century4 ,with the rise of the first ,new ,york ,state ,survey 7#ahcf-ahdc7 and that of ,pennsylvania 7#ahcf-ahdd1 #aheh71 ,american geology became more or less independent of ,europe4 ,finally1 this article will conclude with a survey of the rise of paleometeorology1 paleogeography1 evolution1 and invertebrate paleontology4 ,the ,rise of ,geology in ,europe4 ,mineral ,geology4--,the geological sciences had their rise in the study of minerals as carried on by the ,german chemist and physician ,george ,bauer 7#adid-aeee71 better known as ,agricola4 ,bauer originated the critical study of minerals1 but did not distinguish his 8fossilia10 the remains of organisms1 from the inorganic crystal forms4 ,mineral geology endured until the close of the eighteenth century4 ,cosmogonists4--,then came the expounders of the earth's origin1 the cosmogonists of the sixteenth to the end of the eighteenth centuries4 ,the fashion of this time was to write histories of the earth derived out of the imagination4 ,earliest ,historical ,geology4--,even though ,giovanni ,arduino 7#agac-agie7 of ,padua was not the first to classify the rocks into three series according to their age1 he did this more clearly than any one else before his time4 ,the rocks about ,verona he grouped in #agei into ,primary1 ,secondary1 ,tertiary1 and ,volcanic4 ,this three-fold classification came into general use1 though modified with time4 ,early in the nineteenth century it had become plain that formations of very varying ages were included in each one of the three series4 ,through the study of the fossils and the recognition of the fact that mountain ranges have been raised at various times1 causing younger fossiliferous strata to take on the characters of the ,primary1 it was seen that these terms of ,arduino had lost their original significance4 ,the first one to describe in detail a local stratigraphic sequence was ,johann ,gottlob ,lehmann 7died #agfg74 ,in #agef he published 8one of the classics of geological literature10 distinguishing clearly thirty successive sedimentary deposits1 some of which he said had fossils1 but he did not use them to distinguish the strata4 ,what ,lehmann did for the ,permian system1 ,george ,christian ,fchsel 7#agbb-aggc7 did even better for the ,triassic of ,thuringia1 in #agfb and #aggc4 ,he pointed out not only the sequence1 but also how the gently inclined strata rest upon the older upturned masses of the mountains2 also that some formations have only marine fossils1 while others have only terrestrial forms and thus indicate the proximity of land4 ,the deformed strata he thought had fallen into the hollows within the earth1 great caverns that had also consumed much of the oceanic waters and had in so doing greatly lowered the sea-level4 ,it was ,fchsel who first introduced the theory of universal formations1 and who defined the term formation1 using it as we now do1 system or period4 ,even though ,lehmann and ,fchsel showed that there was a definite order and process in the formation of the earth's crust1 their example was barren of followers until the beginning of the eighteenth century4 ,wernerian ,geology or ,geognosy4--,we come now to the time of ,abraham ,gottlob ,werner 7#agdi-ahag71 who from #agge to #ahag was professor of mining and mineralogy in the ,freiberg ,academy of ,mines4 ,geikie1 in his most interesting ,founders of ,geology1 says that ,werner 8bulks far more largely in the history of geology than any of those with whom up to the present we have been concerned--a man who wielded an enormous authority over the mineralogy and geology of his day40 8,although he did great service by the precision of his lithological characters and by his insistence on the doctrine of geological succession1 yet as regards geological theory1 whether directly by his own teaching1 or indirectly by the labors of his pupils and followers1 much of his influence was disastrous to the higher interests of geology40 ,werner arranged the crust of the earth into a series of formations1 as had been done previously by ,lehmann and ,fchsel1 and one of his fundamental postulates was that all rocks were chemically precipitated in the ocean as 8universal formations40 ,for this reason ,werner's school were called the ,neptunists4 ,nowhere1 however1 did he explain how and where the deep and primitive ocean had disappeared4 ,according to ,werner1 the first formed or oldest rocks were the chemically deposited ,primitive strata1 including granite and other igneous and metamorphic rocks4 ,on these followed the ,transition rocks1 the earliest sediments of mechanical origin1 and above them the ,floetz rocks1 a term for the horizontal stratified rocks4 ,these last he said were partly of chemical but chiefly of mechanical origin4 ,last of all came the ,alluvial series4 ,the existence of volcanoes had been pointed out long before ,werner's time by the ,italian school of geologists1 but as for 8the universality and potency of what is now termed igneous action10 all was 8brushed aside by the oracle of ,freiberg40 ,reactions between the interior and exterior of our earth 8were utterly antagonistic to ,werner's conception of the structure and history of the earth40 ,to him1 volcanoes were 8burning mountains0 that arose from the combustion of subterranean beds of coal1 spontaneously ignited4 ,the breaking down of the ,wernerian doctrines began with two of ,werner's most distinguished pupils1 ,d',aubuisson de ,voisins 7#agfi-ahai7 and ,von ,buch4 ,the former in #ahjc had accepted ,werner's aqueous origin of basalt1 but after studying the celebrated and quite recent volcanic area of ,auvergne he recanted in #ahjd4 ,here he saw the basaltic rocks lying upon and cutting through granite1 and in places more than #abjj feet thick4 8,if these basaltic rocks were lavas10 says ,geikie1 8they must1 according to the ,wernerian doctrine1 have resulted from the combustion of beds of coal4 ,but how could coal be supposed to exist under granite1 which was the first chemical precipitate of a primeval ocean80 ,leopold von ,buch 7#aggd-ahec71 8the most illustrious geologist that ,germany has produced10 after two years spent in ,norway was satisfied 8that the rocks in the ,christiania district could not be arranged according to the ,wernerian plan1 which there completely broke down4 ,von ,buch found a mass of granite lying among fossiliferous limestones which were manifestly metamorphosed1 and were pierced by veins of granite1 porphyry1 and syenite40 ,even so1 he was not ready to abandon the teachings of his master4 ,after a study of the mountain systems of ,germany1 however1 8he declared that the more elevated mountains had never been covered by the sea1 as ,werner had taught1 but were produced by successive ruptures and uplifts of the terrestrial crust0 7,geikie74 ,rise of ,geology and ,conformism4--,modern geology has its rise in ,james ,hutton 7#agbf-agig7 of ,edinburgh1 ,scotland4 ,in #aghe and #agie1 ,hutton published his ,theory of the ,earth1 with ,proofs and ,illustrations4 ,his 8immortal theory0 is his only work on geology4 8,fortunately for ,hutton's fame and for the onward march of geology1 the philosopher numbered among his friends the illustrious mathematician and natural philosopher1 ,john ,playfair 7#agdh-ahai71 who had been closely associated with him in his later years1 and was intimately conversant with his geological opinions40 ,in #ahjb1 ,playfair published his ,illustrations of the ,huttonian ,theory of the ,earth1 of which ,geikie says1 8,of this great classic it is impossible to speak too highly10 as it is at the basis of all modern geology4 ,one of ,hutton's fundamental doctrines is that the earth is internally hot and that in the past large masses of molten material1 the granites1 have been intruded into the crust4 ,it was these igneous views that led to his followers being called the ,plutonists4 ,another of his great doctrines was that 8the ruins of an earlier world lie beneath the secondary strata10 and that they are separated by what is now known as unconformity4 ,he clearly recognized a lost interval in the broken relation of the structures1 and that the ruins1 the detrital materials1 of one world after another are superposed in the structure of the earth4 ,hutton also held that the deformation of once horizontally deposited strata was probably brought about at different periods by great convulsions that shook the very foundations of the earth4 ,after a convulsion1 there was a long time of erosion1 represented by the unconformity4 ,geikie says1 8,the whole of the modern doctrine of earth sculpture is to be found in the ,huttonian theory40 ,the ,lyellian doctrine of metamorphism had its origin in ,hutton1 for he showed that invading igneous granite had altered1 through its heat and expanding power1 the originally waterlaid sediments1 and that the schists of the ,alps had been born of the sea like other stratified rocks4 ,hutton is the father of the ,uniformitarian principle1 for he 8started with the grand conception that the past history of our globe must be explained by what can be seen to be happening now1 or to have happened only recently4 ,the dominant idea in his philosophy is that the present is the key to the past40 ,this principle has been impressed on all later geologists by ,sir ,charles ,lyell1 and is the chief cornerstone of modern geology4 ,the principle of uniformitarianism has underlain geologic interpretation since the days of ,hutton1 ,playfair1 and ,lyell4 ,however1 it is often applied too rigidly in interpretations based upon the present conditions1 because in the past there were long times when the topographic features of the earth were very different from those of to-day4 ,throughout the ,paleozoic1 and1 less markedly1 the ,mesozoic1 the oceans flooded the lands widely 7at times over #fj per cent of the total area71 highlands were inconspicuous1 sediments far scarcer1 and climates warm and equable throughout the world4 ,highland conditions1 and especially the broadly emergent continents of the present1 were only periodically present in the ,paleozoic and then for comparatively short intervals between the periods4 ,therefore rates of denudation1 solution1 sedimentation1 and evolution have varied greatly throughout the geological ages4 ,these differences1 however1 relate to degrees of operation1 and not to kinds of processes2 but the differences in degree of operation react mightily on our views as to the age of the earth4 ,geologic time had1 for ,hutton1 no 8vestige of a beginning1 no prospect of an end40 ,in other words1 geologic time is infinite4 ,he did not1 however1 discover a method by which the chronology of the earth could be determined4 ,first ,important ,text-books4--,in #ahbb appeared the ablest text-book so far published1 and the pattern for most of the later ones1 ,outlines of the ,geology of ,england and ,wales1 by ,w4 ,d4 ,conybeare 7#aghg-aheg7 and ,w4 ,phillips 7#agge-ahbh74 8,in this excellent volume all that was then known regarding the rocks of the country1 from the youngest formations down to the ,old ,red ,sandstone1 was summarized in so clear and methodical a manner as to give a powerful impulse to the cultivation of geology in ,england0 7,geikie74 ,this book is reviewed at great length by ,edward ,hitchcock in the ,journal 7#g1 #bjc1 #ahbd74 ,to indicate how far historical geology had progressed up to #ahbb in ,england1 a digest of the geological column as presented in this text-book is given in the following table1 along with other information4 ,a text-book writer of yet greater influence was ,charles ,lyell 7#agig-ahge71 whose ,principles of ,geology appeared in three volumes between #ahcj and #ahcc4 ,this and his other books were kept up to date through many editions1 and his ,elements of ,geology is1 as ,geikie says1 8the hand book of every ,english geologist0 working with the fossiliferous formations4 ,the ,rise of ,geology in ,north ,america4 ,the ,generating ,centers4--,in ,america1 geology had its rise independently in three places3 in the two scientific societies of ,boston and ,philadelphia1 and dominantly in ,benjamin ,silliman of ,yale ,college4 ,stated in another way1 we may say that geology in ,america had its origin in the following pioneers and founders3 first1 in ,william ,maclure at ,philadelphia1 and next in ,benjamin ,silliman at ,new ,haven4 ,through the influence of the latter1 ,amos ,eaton1 the botanist1 became a geologist and taught geology at ,williams ,college and later at the ,rensselaer ,school in ,troy1 ,new ,york4 ,through the same influence ,rev4 ,edward ,hitchcock also became a geologist and taught the subject after #ahbe at ,amherst ,college4 ,silliman was the first to take up actively the teaching of mineralogy and geology based on collections of specimens4 ,he spread the knowledge in popular lectures throughout the ,eastern ,states1 graduated many a student in the sciences1 making of some of them professional teachers and geologists1 provided all with a journal wherein they could publish their research1 organized the first geological society and through his students the first official geological surveys1 and by kind words and acts stimulated1 fostered1 and held together ,american scientific men for fifty years4 ,of him it has been truly said that he was 8the guardian of ,american science from its childhood40 ,the ,american ,academy in ,boston4--,the second oldest scientific society1 but the first one to publish on geological subjects1 was the ,american ,academy of ,arts and ,sciences of ,boston1 instituted and publishing since #aghj4 ,up to the time of the founding of this ,journal1 there had appeared in the publications of the ,american ,academy about a dozen papers of a geologic character1 none of which need to be mentioned here excepting one by ,s4 ,l4 and ,j4 ,f4 ,dana1 entitled 8,outlines of the ,mineralogy and ,geology of ,boston10 published in #ahah4 ,this is an early and important step in the elucidation of one of the most intricate geologic areas1 and is further noteworthy for its geologic map1 the third one to appear1 the older ones being by ,maclure and ,hitchcock 7,merrill74 ,,the ,,geological ,,column ,,in #ahbb ,present ,american classification ,conybeare and ,c4 ,p4 ,phillips #ahbb orders ,superior ,psychozoic or ,recent ,alluvial ,order ,cenozoic ,pleistocene ,diluvial ,upper ,marine formation 7,crag1 ,pliocene ,neogene ,bagshot sand1 and ,isle of ,wight7 ,miocene ,fresh-water formations ,oligocene ,paleogene ,london ,clay ,eocene ,plastic ,clay ,supermedial ,mesozoic ,cretaceous ,chalk ,order ,beds between ,chalk and ,oolite ,series ,comanchian #ahhg 7,chalk ,marle1 ,green ,sand1 ,weald ,clay1 ,iron ,sand7 ,upper ,oolitic division 7,purbeck ,jurassic #ahbi beds1 ,portland ,oolite1 ,kimmeridge ,clay7 ,middle ,oolitic division 7,coral ,rag1 ,oxford ,clay7 ,lower ,oolitic division 7,cornbrash ,stonesfield ,slate1 ,forest ,marble1 ,great ,oolite1 ,fullers' ,earth1 ,inferior ,oolite1 ,sand and ,marlestone7 ,lias ,triassic #ahcd ,new ,red ,sandstone ,paleozoic ,permian #ahda ,magnesian ,limestone ,medial or ,coal ,measures,carboniferous ,order ,pennsylvanian #ahia ,millstone ,mississippian #ahfi ,grit and ,shale ,old ,red ,sandstone ,devonian #ahci ,unresolved ,submedial ,silurian #ahce and ,inferior ,orders ,ordovician #ahgi 7,lower ,silurian #ahce7 ,cambrian #ahcc ,proterozoic,keweenawan ,huronian #aheb ,animikian ,huronian ,sudburian ,archeozoic ,keewatin ,laurentian #ahec ,coutchiching ,present ,american classification ,wernerian ,other orders writers ,newest ,tertiary ,psychozoic or ,recent ,floetz ,class ,class ,cenozoic ,pleistocene ,pliocene ,neogene ,miocene ,oligocene ,paleogene ,eocene ,primitive ,primitive ,transition,intermediate ,mesozoic ,cretaceous and ,floetz and ,classes ,secondary classes ,comanchian #ahhg ,jurassic #ahbi ,triassic #ahcd ,paleozoic ,permian #ahda ,pennsylvanian #ahia ,mississippian #ahfi ,devonian #ahci ,silurian #ahce ,ordovician #ahgi 7,lower ,silurian #ahce7 ,cambrian #ahcc ,proterozoic,keweenawan ,huronian #aheb ,animikian ,huronian ,sudburian ,archeozoic ,keewatin ,laurentian #ahec ,coutchiching ,early ,geology in ,philadelphia4--,the oldest scientific society is the ,american ,philosophical ,society of ,philadelphia1 started by the many-sided ,benjamin ,franklin in #agfi1 and which has published since #agga4 ,up to the time of the founding of the ,journal in #ahah1 there had appeared in the publications of this society thirteen papers of a geologic nature1 nearly all small building stones in the rising geologic story of ,north ,america4 ,the only fundamental ones were ,maclure's ,observations of #ahji and #ahag4 ,later1 in this same city1 there was organized another scientific society that came to be for a long time the most active one in ,america4 ,this was the ,academy of ,natural ,sciences1 started in #ahab with seven members1 but it was not until #ahag and the election of ,william ,maclure as its first president that the work of the ,academy was of a far-reaching character4 ,here was built up not only a society for the advancement of the natural sciences and publications for the dissemination of such knowledge1 but1 what is equally important1 the first large library and general museum4 ,william ,maclure 7#agfc-ahdj71 correctly named by ,silliman the 8father of ,american geology10 was born and educated in ,scotland1 and died near ,mexico ,city4 ,a merchant of ,london until #agif1 when he had already amassed 8a considerable fortune10 he made a first short visit to ,new ,york ,city in #aghb4 ,in #agif he again came to ,america1 this time to become a citizen of this country and a liberal patron of science4 ,about #ahjc1 single-handed and unsustained by government patronage1 ,maclure interested himself most zealously and efficiently in ,american geology4 ,in #ahji he published his ,observations on the ,geology of the ,united ,states1 ,explanatory of a ,geological ,map4 ,this work he revised 8on a yet more extended scale10 issuing it in #ahag with #acj pages of text1 accompanied by a large colored geological map4 ,silliman1 the ,pioneer ,promoter of ,geology4--,in #ahjf when ,benjamin ,silliman 7#aggi-ahfd7 began actively to teach chemistry and mineralogy1 all the sciences in ,america were in a very backward state1 and the earth sciences were not recognized as such in the curricula of any of our colleges4 ,silliman gave his first lecture in chemistry on ,april #d1 #ahjd4 ,in the summer of that year1 ,yale ,college asked him to go to ,england to purchase material for the ,college1 and great possibilities for broadening his knowledge now loomed before him4 ,as ,silliman himself 7#dc1 #bbe1 #ahdb7 has told the interesting story of his sojourn in ,england and ,scotland1 it is worth while to restate a part of it here4 8,passing over to ,england in the spring of #ahje1 and fixing my residence for six months in ,london1 ,i found there no school1 public or private1 for geological instruction1 and no association for the cultivation of the science1 which was not even named in the ,english universities40 ,in geology 8,edinburgh was then far in advance of ,london4444 ,prof4 ,jameson having recently returned from the school of ,werner1 fully instructed in the doctrines of his illustrious teacher1 was ardently engaged to maintain them1 and his eloquent and acute friend1 the late ,dr4 ,john ,murray1 was a powerful auxiliary in the same cause2 both of these philosophers strenuously maintaining the ascendancy of the aqueous over the igneous agencies1 in the geological phenomena of our planet4 ,on the other hand1 the disciples and friends of ,dr4 ,hutton were not less active4 ,he died in #agig1 and his mantle fell upon ,sir ,james ,hall1 who1 with ,prof4 ,playfair and ,prof4 ,thomas ,hope1 maintained with signal ability1 the igneous theory of ,hutton4 ,it did not become one who was still a youth and a novice1 to enter the arena of the geological tournament where such powerful champions waged war2 but it was very interesting to view the combat1 well sustained as it was on both sides1 and protracted1 without a decisive issue1 into a drawn battle4444 ,the conflicts of the rival schools of ,edinburgh--the ,neptunists and the ,vulcanists1 the ,wernerians and the ,huttonians1 were sustained with great zeal1 energy1 talent1 and science2 they were indeed marked too decidedly by a partisan spirit1 but this very spirit excited untiring activity in discovering1 arranging1 and criticising the facts of geology4 ,it was a transition period between the epoch of geological hypotheses and dreams1 which had passed by1 and the era of strict philosophical induction1 in which the geologists of the present day are trained4444 ,i was a diligent and delighted listener to the discussions of both schools4 ,still the igneous philosophers appeared to me to assume more than had been proved regarding internal heat4 ,in imagination we were plunged into a fiery ,phlegethon1 and ,i was glad to find relief in the cold bath of the ,wernerian ocean1 where my predilections inclined me to linger40 ,silliman's ,students and ,their ,publications4--,silliman's first student to take up geology as a profession was ,denison ,olmstead 7#agia-ahei71 educator1 chemist1 and geologist1 who was graduated from ,yale in #ahac4 ,four years later he was under special preparation with ,silliman in mineralogy and geology1 and in that year was appointed professor of chemistry in the ,university of ,north ,carolina4 ,in #ahbd-ahbe ,olmstead issued a ,report on the ,geology of ,north ,carolina1 which is the first official geological report issued by any state in ,america1 8a conspicuous and solitary instance10 according to ,hitchcock's review of it 7#ad1 #bcj1 #ahbh71 8in which any of our state governments have undertaken thoroughly to develop their mineral resources40 ,amos ,eaton 7#aggf-ahdb71 lawyer1 botanist1 surveyor1 and one of the founders of ,american geology1 was a graduate of ,williams ,college in the class of #agii4 ,he studied with ,silliman in #ahae1 attending his lectures on chemistry1 geology1 and mineralogy4 ,he also enjoyed access to the libraries of ,silliman and of the botanist1 ,levi ,ives1 in which works on botany and materia medica were prominent1 and was a diligent student of the ,college cabinet of minerals4 ,he settled as a lawyer and land agent in ,catskill1 ,new ,york1 and here in #ahaj he gave a popular course of lectures on botany1 believed to have been the first attempted in the ,united ,states4 ,in #ahah appeared ,eaton's first noteworthy geological publication1 the ,index to the ,geology of the ,northern ,states1 a text-book for the classes in geology at ,williamstown4 ,the controlling principle of this book was ,wernerism1 a false doctrine from which ,eaton was never able to free himself4 ,this book was 8written over anew0 and published in #ahbj4 ,while at ,albany in #ahah1 ,governor ,de ,witt ,clinton asked ,eaton to deliver a course of lectures on chemistry and geology before the members of the legislature of ,new ,york4 ,it is believed that ,eaton is the only ,american having this distinction1 and because of it he became acquainted with many leading men of the state1 interesting them in geology and its application to agriculture by means of surveys4 ,in this way was sown the idea which eventually was to fructify in that great official work3 ,the ,natural ,history of ,new ,york4 7,see #dc1 #bae1 #ahdb2 and ,youmans' sketch of ,eaton's life1 ,pop4 ,sci4 ,monthly1 ,nov4 #ahij47 ,edward ,hitchcock 7#agic-ahfd71 reverend1 state geologist1 college president1 and another of the founders of ,american geology1 was largely self-taught4 ,previous to #ahbe1 when he entered the theological department of ,yale ,college1 he had met ,amos ,eaton1 who interested him in botany and mineralogy1 and between #ahae and #ahai he had made lists of the plants and minerals found about his native town1 ,deerfield1 ,massachusetts4 ,therefore1 while studying theology at ,yale it was natural for him also to take up mineralogy and geology with ,silliman1 whose acquaintance he had made at least as early as #ahah4 ,hitchcock1 who was destined to be one of the most prominent figures of his time1 was appointed in #ahbe to the chair of chemistry and natural history at ,amherst ,college4 ,his first geologic paper1 one of five pages1 appeared in #ahae4 ,three years later appeared his more important paper on the ,geology and ,mineralogy of a ,section of ,massachusetts1 ,new ,hampshire1 and ,vermont 7#a1 #aje1 #dcf1 #ahah74 ,this is also noteworthy for its geological map1 the next one to be published after those of ,maclure of #ahji and #ahag4 ,in #ahbc came a still greater work1 ,a ,sketch of the ,geology1 ,mineralogy1 and ,scenery of the ,regions contiguous to the ,river ,connecticut 7#f1 #a1 #bjj1 #ahbc2 #g1 #a1 #ahbd74 ,here the map above referred to was greatly improved1 and the survey was one of the most important of the older publications4 ,youmans in his account of ,hitchcock 7,pop4 ,sci4 ,monthly1 ,sept4 #ahie7 says3 8,the ,state of ,massachusetts commissioned him to make a geological survey of her territory in #ahcj4 ,three years were spent in the explorations1 and the work was of such a high character that other ,states were induced to follow the example of ,massachusetts4444 ,the ,state of ,new ,york sought his advice in the organization of a survey1 and followed his suggestions1 particularly in the division of the territory into four parts1 and appointed him as the geologist of the first district4 ,he entered upon the work1 but after a few days of labor he found that he must necessarily be separated from his family1 much to his disinclination4 ,he also conceived the idea of urging a more thorough survey of his own ,state2 hence he resigned his commission and returned home4 ,the effort for a resurvey of ,massachusetts was successful1 and he was recommissioned to do the work4 ,the results appeared in #ahda and #ahdd40 ,oliver ,p4 ,hubbard was assistant to ,silliman in #ahca-ahcf1 and then up to #ahff taught chemistry1 mineralogy1 and geology at ,dartmouth ,college4 ,james ,g4 ,percival was graduated at ,yale in #ahae1 and in #ahce he and ,c4 ,u4 ,shepard of ,amherst ,college were appointed state geologists of ,connecticut4 ,their report was issued in #ahdb4 ,james ,dwight ,dana 7#ahac-ahie7 was undoubtedly the ablest of all of ,silliman's students4 ,graduated at ,yale in #ahcc1 he spent fifteen months in the ,united ,states ,navy as instructor in mathematics1 cruising off ,france1 ,italy1 ,greece1 and ,turkey4 ,in #ahcf he was assistant to ,silliman1 and in #ahcg1 at the age of twenty-four years1 he published his widely used ,system of ,mineralogy4 ,two years later ,dana joined the ,wilkes ,exploring ,expedition as mineralogist1 returning to ,america in #ahdb2 his geological results of this expedition were published in #ahdi4 ,in #ahfc1 during the ,rebellion1 he published his ,manual of ,geology1 and through four editions it remained for forty years the standard text-book for ,american geologists4 ,first ,american ,geological ,society4--,the founding in #ahjg of the ,geological ,society of ,london1 the parent of geological societies1 undoubtedly had its stimulating effect on ,silliman1 and with his marked organizing ability he began to think of forming an ,american society of the same kind4 ,this he brought about the year following the appearance of the ,journal1 that is1 in #ahai4 ,the ,american ,geological ,society1 begun in #ahai 7#a1 #ddb1 #ahai71 was terminated in #ahcj 7#ag1 #bjb1 #ahcj74 ,the first meeting 7,september #f1 #ahai7 and all the subsequent ones were held in the cabinet of ,yale ,college4 ,the brief records of the doings of this society are printed in volumes #a1 #aj1 #ae1 and #ah of the ,journal4 ,silliman was the attraction at the meetings1 surrounded by his mineral cabinet1 and he gave 8the true scientific dress to all the naked mineralogical subjects0 discussed4 ,wernerian ,geology in ,north ,america4 ,the ,father of ,american ,geology4--,historical ,geology begins in ,america with ,william ,maclure's ,observations on the ,geology of the ,united ,states1 issued in #ahji4 ,this was the first important original work on ,north ,american geology1 and its colored geological map was the first one of the area east of the ,mississippi ,river4 ,the classification was essentially the ,wernerian system4 ,all of the strata of the ,coastal ,plain1 now known to range from the ,lower ,cretaceous to ,recent1 were referred to the ,alluvial4 ,to the west1 over the area of the ,piedmont1 were his ,primitive rocks1 while the older ,paleozoic formations of the ,appalachian ranges were referred to the ,transition4 ,west of the folded area1 all was ,floetz or ,secondary1 or what we now know as ,paleozoic sedimentaries4 ,the ,triassic of the ,piedmont area and that of ,connecticut he called the ,old ,red ,sandstone1 and the coal formations of the interior region he said rested upon the ,secondary4 ,the second edition of the work in #ahag was much improved1 along with the map1 which was also printed on a more correct geographic base4 7,for greater detail1 see ,merrill1 ,contributions to the ,history of ,american ,geology1 #aijf47 ,even though ,maclure's geologic maps are much generalized1 and the scheme of classification adopted a very broad one1 they are in the main correct1 even if they do emphasize unduly the rather simple geologic structure of ,north ,america4 ,this fact is patent all through ,maclure's description4 ,cleaveland also refers to it in his treatise of #ahaf1 and ,silliman in the opening volume of the ,journal 7#a1 #g1 #ahah7 says3 8,the outlines of ,american geology appear to be particularly grand1 simple1 and instructive40 ,then1 all the kinds of rocks were comprehended under four classes1 ,primitive1 ,transition1 ,alluvial1 and ,volcanic4 ,it is also interesting to note here that in #ahbb ,maclure had lost faith in the aqueous origin of the igneous rocks and writes of the ,wernerian system as 8fast going out of fashion0 7#e1 #aig1 #ahbb71 while ,hitchcock said about the same thing in #ahbe 7#i1 #adf74 ,the ,work of ,eaton4--,amos ,eaton1 after traveling #aj1jjj miles and completing his ,erie ,canal ,report in #ahbd1 8reviewed the whole line several times10 and published in #ahbh in the ,journal 7#ad1 #ade7 a paper on ,geological ,nomenclature1 ,classes of ,rocks1 etc4 ,the broader classification is the ,wernerian one of ,primitive1 ,transition1 and ,secondary classes4 ,under the first two he has fossiliferous early ,paleozoic formations1 but does not know it1 because he pays no attention anywhere to the detail of the entombed fossils1 and all of his ,secondary is what we now call ,paleozoic4 ,the correlations of the latter are faulty throughout4 ,then came his paper of #ahcj1 ,geological ,prodromus 7#ag1 #fc71 in which he says3 8,i intend to demonstrate 444 that all geological strata are arranged in five analogous series2 and that each series consists of three formations2 viz41 the ,carboniferous meaning mud-stones1 ,quartzose1 and ,calcareous40 ,we seem to see here expressed for the first time the idea of 8cycles of sedimentation10 but ,eaton does not emphasize this idea1 and the localities given for each 8formation0 of 8analogous series0 demonstrate beyond a doubt that he did not have a sedimentary sequence4 ,the whole is simply a jumble of unrelated formations that happen to agree more or less in their physical characters4 8,i intend to demonstrate10 he says further1 8that the detritus of ,new ,jersey1 embracing the marle1 which contains those remarkable fossil relics1 is antediluvial1 or the genuine ,tertiary formation40 ,this correlation had been clearly shown by ,finch in #ahbd 7#g1 #ca7 and yet both are in error in that they do not distinguish the included ,cretaceous marls and greensands as something apart from the ,tertiary4 ,one gets impatient with the later writings of ,eaton1 because he does not become liberalized with the progressive ideas in stratigraphic geology developing first in ,europe and then in ,america1 especially among the geologists of ,philadelphia4 ,therefore it is not profitable to follow his work further4 ,early ,american ,text-books of ,geology4--,the first ,american text-book of geology bears the date of ,boston #ahaf and is entitled ,an ,elementary ,treatise on ,mineralogy and ,geology1 its author being ,parker ,cleaveland of ,bowdoin ,college4 ,the second edition appeared in #ahbb4 ,it also had a geologic map of the ,united ,states1 practically a copy of ,maclure's4 ,to mineralogy were devoted #ehe pages1 and to geology #ee1 of which #cg describe rocks and #e the geology of the ,united ,states4 ,the chronology is ,wernerian4 ,of 8geological systems0 there are two1 8primitive and secondary rocks40 ,in #ahah appeared ,amos ,eaton's ,index to the ,geology of the ,northern ,states1 having #ed pages1 and in #ahbj came the second edition1 8wholly written over anew10 with #bhf pages4 ,the theory of the later edition is still that of ,werner1 with 8improvements of ,cuvier and ,bakewell10 and yet one sees now-a-days but little in it of the far better ,english text-book4 ,eaton did very little to advance philosophic geology in ,america4 ,what is of most value here are his personal observations in regard to the local geology of western ,massachusetts1 ,connecticut1 southwestern ,vermont1 and eastern ,new ,york 7#a1 #fi1 #ahai2 also ,merrill1 p4 #bcd74 ,we come now to the most comprehensive and advanced of the early text-books used in ,america4 ,this is the third ,english edition of ,robert ,bakewell's ,introduction to ,geology 7#djj pages1 #ahbi71 and the first ,american edition 8with an ,appendix ,containing an ,outline of his ,course of ,lectures on ,geology at ,yale ,college1 by ,benjamin ,silliman0 7#abh pages74 ,bakewell's good book is in keeping with the time1 and while not so advanced as ,conybeare and ,phillips's ,outlines of #ahbb1 yet is far more so than ,silliman's appendix4 ,the latter is general and not specific as to details2 it is still decidedly ,wernerian1 though in a modified form4 ,silliman says he is 8neither ,wernerian nor ,huttonian10 and yet his summary on pages #abj to #abf shows clearly that he was not only a ,wernerian but a pietist as well4 ,unearthing of the ,cenozoic and ,mesozoic in ,north ,america4 ,the ,discerning of the ,tertiary4--,the ,new ,england ,states1 with their essentially igneous and metamorphic formations1 could not furnish the proper geologic environment for the development of stratigraphers and paleontologists4 ,so in ,america we see the rise of such geologists first in ,philadelphia1 where they had easy access to the horizontal and highly fossiliferous strata of the coastal plain4 ,the first one to attract attention was ,thomas ,say1 after him came ,john ,finch1 followed by ,lardner ,vanuxem1 ,isaac ,lea1 ,samuel ,g4 ,morton1 and ,t4 ,a4 ,conrad4 ,these men not only worked out the succession of the ,cenozoic and the upper part of the ,mesozoic1 but blazed the way among the ,paleozoic strata as well4 ,thomas ,say 7#aghg-ahcd71 in #ahai1 was the first ,american to point out the chronogenetic value of fossils in his article1 ,observations on some ,species of ,zoophytes1 ,shells1 etc41 principally ,fossil 7#a1 #cha74 ,he correctly states that the progress of geology 8must be in part founded on a knowledge of the different genera and species of reliqui1 which the various accessible strata of the earth present40 ,say fully realizes the difficulties in the study of fossils1 because of their fragmental character and changed nature1 and that their correct interpretation requires a knowledge of similar living organisms4 ,the application of what ,say pointed out came first in ,john ,finch's ,geological ,essay on the ,tertiary ,formations in ,america 7#g1 #ca1 #ahbd74 ,even though the paper is still laboring under the mineral system and does not discern the presence of ,cretaceous strata among his ,tertiary formations1 yet ,finch also sees that 8fossils constitute the medals of the ancient world1 by which to ascertain the various periods40 ,finch now objects to the wide misuse in ,america of the term alluvial and holds that it is applied to what is elsewhere known as ,tertiary4 ,he says3 8,geology will achieve a triumph in ,america1 when the term alluvial shall be banished from her ,geological ,essays1 or confined to its legitimate domain1 and then her tertiary formations will be seen to coincide with those of ,europe1 and the formations of ,london1 ,paris1 and the ,isle of ,wight1 will find kindred associations in ,virginia1 the ,carolinas1 ,georgias1 the ,floridas1 and ,louisiana40 ,the formations as he has them from the bottom upwards are3 7#a7 ,ferruginous sand1 7#b7 ,plastic clay1 7#c7 ,calcaire ,silicieuse of the ,paris ,basin1 7#d7 ,london ,clay1 7#e7 ,calcaire ,ostre1 7#f7 ,upper marine formation1 7#g7 ,diluvial4 ,the grandest of these early stratigraphic papers1 however1 is that by ,lardner ,vanuxem 7#agib-ahdh71 of only three pages1 entitled 8,remarks on the ,characters and ,classification of ,certain ,american ,rock ,formations0 7#af1 #bed1 #ahbi74 ,vanuxem1 a cautious man and a profound thinker1 had been educated at the ,paris ,school of ,mines4 ,james ,hall told the writer in a conversation that while the first ,new ,york ,state ,survey was in operation1 all of its members looked to ,vanuxem for advice4 ,in the paper above referred to1 ,vanuxem points out in a very concise manner that3 8,the alluvial of ,mr4 ,maclure 444 contains not only well characterized alluvion1 but products of the tertiary and secondary classes4 ,littoral shells1 similar to those of the ,english and ,paris basins1 and pelagic shells1 similar to those of the chalk deposition or latest secondary1 abound in it4 ,these two kinds of shells are not mixed with each other2 they occur in different earthy matter1 and1 in the southern states particularly1 are at different levels4 ,the incoherency or earthiness of the mass1 and our former ignorance of the true position of the shells1 have been the sources of our erroneous views40 ,the second error of the older geologists1 according to ,vanuxem1 was the extension of the secondary rocks over 8the western country1 and the back and upper parts of ,new ,york40 ,they are now called ,paleozoic4 ,some had even tried to show the presence of ,jurassic here because of the existence of olite strata4 8,it was taken for granted1 that all horizontal rocks are secondary1 and as the rocks of these parts of the ,united ,states are horizontal in their position1 so they were supposed to be secondary40 ,he then shows on the basis of similar ,ordovician fossils that the rocks of ,trenton ,falls1 ,new ,york1 recur at ,frankfort in ,kentucky1 and at ,nashville in ,tennessee4 8,it is also certain that an uplifting or downfalling force1 or both1 have existed1 but it is not certain that either or both these forces have acted in a uniform manner4444 ,innumerable are the facts1 which have fallen under my observation1 which show the fallacy of adopting inclination for the character of a class10 such as the ,transition class of strata4 ,he then goes on to say that in the interior of our country the so-called secondary rocks are horizontal and in the mountains to the east the same strata are highly inclined4 8,the analogy1 or identity of rocks1 ,i determine by their fossils in the first instance1 and their position and mineralogical characters in the second or last instance40 ,it appears that ,isaac ,lea 7#agib-ahhf7 in his ,contributions to ,geology1 #ahcc1 was the first to transplant to ,america ,lyell's terms1 ,pliocene1 ,miocene1 and ,eocene1 proposed the previous year4 ,the celebrated ,claiborne locality was made known to ,lea in #ahbi1 and in the work here cited he describes from it #bej species1 of which #bjj are new4 ,the horizon is correlated with the ,london ,clay and with the ,calcaire ,grossier of ,france1 both of ,eocene time 7#be1 #dac1 #ahcd74 ,timothy ,a4 ,conrad began to write about the ,american ,tertiary in #ahcj1 and his more important publications were issued at ,philadelphia4 ,his papers in the ,journal begin with #ahcc and the last one on the ,tertiary is in #ahdf4 ,the ,tertiary faunas and stratigraphy have been modernized by ,william ,h4 ,dall in his monumental work of #afej pages and #fj plates entitled 8,contributions to the ,tertiary ,fauna of ,florida0 7#ahhe-aijc74 ,here more than #cafj forms of the ,atlantic and ,gulf deposits are described1 but in order to understand their relations to the fossil faunas elsewhere and to the living world1 the author studied over #aj1jjj species4 ,since then1 many other workers have interested themselves in the ,tertiary problems4 ,much good work is also being done in the ,pacific ,states where the sequence is being rapidly developed4 ,the ,discerning of the ,eastern ,cretaceous4--,the ,cretaceous sequence was first determined by that 8active and acute geologist10 ,samuel ,g4 ,morton 7#agii-ahea71 but that these rocks might be present along the ,atlantic border had been surmised as early as #ahbd by ,edward ,hitchcock 7#g1 #baf74 ,vanuxem1 as above pointed out1 indicated the presence of the ,cretaceous in #ahbi4 ,in this same year ,morton proved its presence before the ,philadelphia ,academy of ,natural ,sciences4 ,between #ahcj and #ahce ,morton published a series of papers in the ,journal under the title 8,synopsis of the ,organic ,remains of the ,ferruginous ,sand ,formation of the ,united ,states1 with ,geological ,remarks0 7#ag1 #bgd1 et seq474 ,in these he describes the ,cretaceous fossils and demonstrates that the 8,diluvial0 and ,tertiary strata of the ,atlantic border also have a long sequence of ,cretaceous formations4 ,in the opening paper he writes3 8,i consider the marl of ,new ,jersey as referable to the great ferruginous sand series1 which in ,prof4 ,buckland's arrangement is designated by the name of green sand4444 ,on the continent this series is called the ancient chalk 444 lower chalk10 etc4 ,again1 the marls of ,new ,jersey are 8geologically equivalent to those beds which in ,europe are interposed between the white chalk and the ,olites40 ,this correlation is with the ,european ,lower ,cretaceous1 but we now know the marls to be of ,upper ,cretaceous age4 ,although ,eaton objected strenuously to ,morton's correlation1 we find ,m4 ,dufresnoy of ,france saying1 8,your limestone above green sand reminds me very much of the ,mstricht beds10 a correlation which stands to this day 7#bb1 #id1 #ahcb74 ,in #ahcc ,morton announces that the ,cretaceous is known all along the ,atlantic and ,gulf border1 and in the ,mississippi valley4 8,the same species of fossils are found throughout10 and none of them are known in the ,tertiary4 ,he now arranges the strata of the former 8,alluvial0 as follows3 ,modern ,alluvial4 ,diluvial4 ,tertiary ,upper ,tertiary 7,upper ,marine74 ,middle ,tertiary 7,london ,clay74 ,lower ,tertiary 7,plastic ,clay74 ,secondary,calcareous ,strata,cretaceous group1 or ,ferruginous ,sand series 7#bd1 #abh74 ,ferruginous ,sand ,western ,cretaceous4--,in #ahda and #ahdc ,j4 ,n4 ,nicollet announced the discovery of ,cretaceous in the ,rocky ,mountain area4 ,of #bj species of fossils collected by him1 #d were said to occur on the ,atlantic border1 and of the #bjj forms of the ,atlantic slope only #a was found in ,europe4 ,here we see pointed out a specific dissimilarity between the continents1 and a similarity between the ,american areas of ,cretaceous deposits 7#da1 #aha2 #de1 #aec74 ,the ,cretaceous of the ,rocky ,mountains was clearly developed by ,f4 ,v4 ,hayden in #ahee-ahhh and by ,f4 ,b4 ,meek 7#aheg-ahgf74 ,other workers in this field were ,charles ,a4 ,white 7#ahfi-ahia71 and ,r4 ,p4 ,whitfield 7#ahgg-ahhi74 ,since #ahia ,t4 ,w4 ,stanton has been actively interpreting its stratigraphy and faunas4 ,cretaceous and ,comanche of ,texas4--,the broader outlines of the ,cretaceous of ,texas had been described by ,ferdinand ,roemer in #aheb in his good work1 ,kreidebildungen von ,texas1 but it was not until #ahhg that ,robert ,t4 ,hill showed in the ,journal 7#cc1 #bia7 that it included two great series1 the ,gulf series1 or what we now call ,upper ,cretaceous1 and a new one1 the ,comanche series4 ,this was a very important step in the right direction4 ,since then the ,comanche series has been regarded by some stratigraphers as of period value1 while others call it ,lower ,cretaceous2 the rest of the ,texas ,cretaceous is divided by ,hill into ,middle and ,upper ,cretaceous4 ,on the other hand1 ,lower ,cretaceous strata had been proved even earlier in the state of ,california1 for here in #ahfi ,w4 ,m4 ,gabb 7#ahci-ahgh7 and ,j4 ,d4 ,whitney 7#ahai-ahif7 had defined their ,shasta group1 which was wholly distinct faunally from the ,comanche of ,texas and the southern part of the ,great ,plains country4 ,jurassic and ,triassic of the ,west4--,in #ahfd1 the ,geological ,survey of ,california proved the presence of marine ,upper ,triassic in that ,state1 and since then it has been shown that not only is all of the ,triassic present in ,idaho 7where it has been known since #ahgg71 ,oregon1 ,nevada1 and ,california1 but that the ,upper ,triassic is of very wide distribution throughout western ,north ,america4 ,jurassic strata1 on the other hand1 were not shown to be present in ,california until #ahhe1 while in the ,rocky ,mountain area of the ,united ,states there was long known an unresolved series of 8,red ,beds0 situated between the ,carboniferous and ,cretaceous4 ,this gave rise to the 8,red ,bed problem10 the history of which is given by ,c4 ,a4 ,white in the ,journal 7#ag1 #bad1 #ahgi74 ,in #ahfi1 ,f4 ,v4 ,hayden announced the discovery of marine ,jurassic fossils in this series1 and since then they have come to be known as the ,sundance fauna1 extending from southern ,utah and ,colorado into ,alaska4 ,above lie the dinosaur-bearing fresh-water deposits1 since #ahid known as the ,morrison beds4 ,in #ahif1 ,o4 ,c4 ,marsh 7#ahca-ahii7 announced the presence of ,jurassic fresh-water strata along the ,atlantic coast 7#b1 #dcc71 but to-day only a small part of them are regarded as of the age of the ,morrison1 while the far greater part are referred to the ,comanche or ,lower ,cretaceous4 ,the red beds below the ,jurassic of the ,rocky ,mountain area have during the past twenty years been shown to be in part of ,upper ,triassic age and of fresh-water origin1 while the greater lower part is connected with the ,carboniferous series and is made up of brackish-- and fresh-water deposits of probable ,permian time4 ,triassic of ,atlantic ,states4--,the fresh-water ,triassic of the ,atlantic border states was first mentioned by ,maclure 7#ahag71 who regarded it as the equivalent of the ,old ,red ,sandstone of ,europe4 ,in this he was followed by ,hitchcock in #ahbc 7#f1 #ci71 the latter saying that above it lies 8the coal formation10 which is true for ,europe1 but in ,america the coal strata are older than these red beds1 now known to be of ,triassic age4 ,the first one to question this correlation was ,alexandre ,brongniart1 who had received from ,hitchcock rock specimens and a fossil fish which he erroneously identified with a ,permian species1 and accordingly referred the strata to the ,permian 7#c1 #bbj1 #ahba2 #f1 #gf1 pl4 #i1 figs4 #a1 #b1 #ahbc74 ,the discerning ,professor ,finch in #ahbf remarked that the red beds of ,connecticut appear to belong 8to the new or variegated sandstone10 because of eight different criteria that he mentions4 ,of these1 but two are of value in correlation1 their 8geological position0 and the presence of bones other than fishes4 ,in the ,connecticut area1 however1 the geological position cannot be determined even to-day1 and in ,finch's time the bones of dinosaurs were unknown4 ,finch then goes on to point out the occurrences of ,old ,red ,sandstone in ,pennsylvania1 but all of the places he refers to are either younger or older in time4 ,here we again see the fatality of trying to make positive correlations on the basis of lithology and color 7#aj1 #bji1 #ahbf74 ,in #ahce1 however1 ,hitchcock showed that the bones that had been found in #ahbj were those of a saurian1 and accordingly referred the strata of the ,connecticut valley to the ,new ,red ,sandstone1 a term that then covered both the ,permian and the ,triassic4 ,in #ahdb1 ,w4 ,b4 ,rogers referred the beds to the ,jurassic1 on the basis of plants from ,virginia4 ,in #ahef1 ,w4 ,c4 ,redfield 7#aghi-aheg71 because of the fishes1 advocated a ,lias1 or ,jurassic age1 and proposed the name ,newark group for all the ,triassic deposits of the ,atlantic border4 ,more recently1 on the basis of the plants studied by ,newberry1 ,fontaine1 ,sturr1 and ,ward1 and the vertebrates described by ,marsh and ,lull1 the age has been definitely fixed as ,upper ,triassic 7see ,dana's ,manual of ,geology1 #gdj1 #ahie74 ,unearthing of the ,paleozoic in ,north ,america4 ,permian of the ,united ,states4--,in ,europe1 previous to #ahda1 the formations now classed as ,permian were included in the ,new ,red ,sandstone1 and with the ,carboniferous were referred to the ,secondary4 ,in that year ,murchison proposed the period term ,permian4 ,in #ahde came the classic ,geology of ,russia in ,europe and the ,ural ,mountains1 by ,murchison1 ,keyserling1 and ,de ,verneuil4 ,in this great work the authors separated out of the ,new ,red the ,magnesian ,limestone of ,great ,britain and the ,rothliegende marls1 ,kupferschiefer1 and ,zechstein of ,germany1 and with other formations of the ,urals in ,russia1 referred them to the ,permian system4 ,this step1 one of the most discerning in historical geology1 was all the more important because they closed the ,paleozoic era with the ,permian1 beginning the ,secondary1 or ,mesozoic1 with the ,new ,red ,sandstone or the ,triassic period4 ,there is a good review of this work by ,d4 ,d4 ,owen 7#ahjg-ahfj7 in the ,journal for #ahdg 7#c1 #aec74 ,owen1 though accepting the ,permian system1 is not satisfied with its reference to the ,paleozoic1 and he sets the matter forth in the ,journal 7#c1 #cfe1 #ahdg74 ,he doubts 8the propriety of a classification which throws the ,permian and ,carboniferous systems into the ,paleozoic period40 ,this is mainly because there is no 8evidence of disturbance or unconformability0 between the ,permian and ,triassic systems4 ,rather 8there is so complete a blending of adjacent strata0 that it is only in ,russia that the ,permian has been distinguished from the ,triassic4 ,this view of ,owen's was not only correct for ,russia but even more so for the ,alps and for ,india1 and it has taken a great deal of work and discussion to fix upon the disconformable contact that distinguishes the ,paleozoic from the ,mesozoic in these areas4 ,in other words1 there was here at this time no mountain making4 ,then ,owen goes on to state that because the ,permian of ,europe has reptiles1 he sees in them decisive ,mesozoic evidence4 8,these are certainly strong arguments in favor of placing1 not only the ,permian1 but also the ,carboniferous group in the ,mesozoic period1 and terminating the ,paleozoic division with the commencement of the coal measures40 ,to this harking backward the geologists of the world have not agreed1 but have followed the better views of ,murchison and his associates4 ,in #ahee ,g4 ,g4 ,shumard discovered1 and in #ahfj his brother ,b4 ,f4 ,shumard 7#ahbj-ahfi7 announced1 the presence of ,permian strata in the ,guadalupe ,mountains of ,texas1 and in #aijb ,george ,h4 ,girty 7#ad1 #cfc7 confirmed this4 ,girty regards the faunas as younger than any other late ,paleozoic ones of ,america1 and says3 8,for this reason ,i propose to give them a regional name1 which shall be employed in a force similar to ,mississippian and ,pennsylvanian4444 ,the term ,guadalupian is suggested40 ,g4 ,c4 ,swallow 7#ahag-ahii7 in #aheh was the first to announce the presence of ,permian fossils in ,kansas1 and this led to a controversy between himself and ,f4 ,b4 ,meek1 both claiming the discovery4 ,it is only in more recent years that it has been generally admitted that there is ,permian in that state1 in ,oklahoma1 and in ,texas4 ,this admission came the more readily through the discovery of many reptiles in the red beds of ,texas1 and through the work of ,c4 ,a4 ,white1 published in #ahia1 ,the ,texan ,permian and its ,mesozoic ,types of ,fossils 7,bull4 ,u4 ,s4 ,geological ,survey1 ,no4 #gg74 ,illustration3 ,james ,hall ,carboniferous ,formations4--,the coal formations are noted in a general way throughout the earliest volumes of the ,journal4 ,the first accounts of the presence of coal1 in ,ohio1 are by ,caleb ,atwater 7#a1 #bbg1 #bci1 #ahai71 and ,s4 ,p4 ,hildreth 7#ac1 #ch1 #dj1 #ahbh74 ,the first coal plants to be described and illustrated were also from ,ohio1 in an article by ,ebenezer ,granger in #ahba 7#c1 #e-g74 ,the anthracite field was first described in #ahbb by ,zachariah ,cist 7#d1 #a7 and then by ,benjamin ,silliman 7#aj1 #cca-cea1 #ahbf72 that of western ,pennsylvania was described by ,william ,meade in #ahbh 7#ac1 #cb74 ,the ,lower ,carboniferous was first recognized by ,w4 ,w4 ,mather in #ahch 7#cd1 #cef74 ,later1 through the work of ,alexander ,winchell 7#ahbd-ahia71 beginning in #ahfb 7#cc1 #ceb7 and continuing until #ahga1 and through the surveys of ,iowa 7#ahee-aheh71 ,illinois 7essentially the work of ,a4 ,h4 ,worthen1 #aheh-ahhh71 ,ohio 7#ahch1 ,mather1 etc471 and ,indiana 7,owen1 etc41 #ahch71 there was eventually worked out the following succession3 ,permian period4 ,upper ,barren series4 ,dunkard group4 ,washington group4 ,pennsylvanian period4 ,upper ,productive ,coal series4 ,monongahela series4 ,lower ,barren ,coal ,measures4 ,conemaugh series4 ,lower ,productive ,coal ,measures4 ,allegheny series4 ,pottsville series4 ,the ,new ,york ,system4--,we now come to the epochal survey of the ,state of ,new ,york1 one that established the principles of1 and put order into1 ,american stratigraphy from the ,upper ,cambrian to the top of the ,devonian4 ,no better area could have been selected for the establishing of this sequence4 ,this survey also developed a stratigraphic nomenclature based on ,new ,york localities and rock exposures1 and made full use of the entombed fossils in correlation4 ,incidentally it developed and brought into prominence ,james ,hall1 who continued the stratigraphic work so well begun and who also laid the foundation for paleontology in ,america1 becoming its leading invertebrate worker4 ,this work is reviewed at great length in the ,journal in the volumes for #ahdd-ahdg by ,d4 ,d4 ,owen4 ,evidently it followed too new a plan to receive fulsome praise from conservative ,owen1 as it should have4 ,he remarks that the volumes 8are not a little prolix1 are voluminous and expensive1 and do not give as clear and connected a view of the geological features of the state as could be wished4444 ,we are of the opinion that before this work can become generally useful and extensively circulated1 it must be condensed and arranged into one compendious volume0 7#df1 #add1 #ahdd74 ,this was never done and yet the work was everywhere accepted at once1 and to this end undoubtedly ,owen's detailed review helped much4 ,the ,natural ,history ,survey of ,new ,york was organized in #ahcf and completed in #ahdc4 ,the state was divided into four districts1 and to these were finally assigned the following experienced geologists4 ,the southeastern part was named the ,first ,district1 with ,w4 ,w4 ,mather 7#ahjd-ahei7 as geologist2 the northeastern quarter was the ,second ,district1 with ,ebenezer ,emmons 7#agii-ahfc7 in charge2 the central portion was the ,third ,district1 under ,lardner ,vanuxem 7#agib-ahdh72 while the western part was ,james ,hall's 7#ahaa-ahih7 ,fourth ,district4 ,paleontology for a time was in charge of ,t4 ,a4 ,conrad 7#ahcj-ahgg72 the mineralogical and chemical work was in the hands of ,lewis ,c4 ,beck2 the botanist was ,john ,torrey2 and the zoologist ,james ,de,kay4 ,the ,new ,york ,state ,survey published six annual reports of #afge pages octavo1 and four final geological reports with #bjgi pages quarto4 ,finally in #ahdf ,emmons added another volume on the soils and rocks of the state1 in which he also discussed the ,taconic and ,new ,york systems2 it has #cga pages4 ,with the completion of the first survey1 ,hall took up his life work under the auspices of the state--his monumental work1 ,paleontology of ,new ,york1 in fifteen quarto volumes of #deci pages and #ajha plates of fossils4 ,in addition to all this1 there are his annual and other reports to the ,regents of the ,state1 so that it is safe to say that he published not less than #aj1jjj pages of printed matter on the geology and paleontology of ,north ,america4 ,in regard to this great series of works1 all that can be presented here is a table of formations as developed by the ,new ,york ,state ,survey4 ,practically all of its results and formation names have come into general use1 with the exception of the ,taconic system of ,emmons and the division terms of the ,new ,york system4 7,see p4 #hh47 ,the ,new ,york ,state ,survey1 begun in #ahcf1 was continued by ,james ,hall from #ahdc to #ahih4 ,during this time he was also state geologist of ,iowa 7#ahee-aheh7 and ,michigan 7#ahfb74 ,since #ahih1 ,john ,m4 ,clarke has ably continued the ,geological ,survey of ,new ,york1 the state which continues to be1 in science and more especially in geology and paleontology1 the foremost in ,america4 ,western ,extension of the ,new ,york system4--,before ,hall finished his final report1 we find him in #ahda on 8a tour of exploration through the states of ,ohio1 ,indiana1 ,illinois1 a part of ,michigan1 ,kentucky1 and ,missouri1 and the territories of ,iowa and ,wisconsin40 ,this tour is described in the ,journal 7#db1 #ea1 #ahdb7 under the caption 8,notes upon the ,geology of the ,western ,states40 ,his object was to ascertain how far the ,new ,york system as the standard of reference 8was applicable in the western extension of the series40 ,in a general way he was very successful in extending the system to the ,mississippi ,river1 and he clearly saw 8a great diminution1 first of sandy matter1 and next of shale1 as we go westward1 and in the whole1 a great increase of calcareous matter in the same direction40 ,he also clearly noted the warped nature of the strata1 the 8anticlinal axis10 since known as the ,cincinnati and ,wabash uplifts and the ,ozark dome4 ,hall1 however1 fell into a number of flagrant errors because of a too great reliance on lithologic correlation and supposedly similar sequence4 ,for instance1 the ,coal ,measures of ,pennsylvania were said to directly overlap the ,chemung group of southern ,new ,york1 and now he finds the same condition in ,ohio1 ,indiana1 and ,illinois1 failing to see that in most places between the top of the ,new ,york system and the ,coal ,measures lay the extensive ,mississippian series1 one that he generally confounded with the ,chemung1 or included in the 8,carboniferous group40 ,he states that the ,portage of ,new ,york is the same as the ,waverly of ,ohio1 and at ,louisville the ,middle ,devonian waterlime is correlated with the similar rock of the ,new ,york ,silurian4 ,hall was especially desirous of fixing the horizon of the ,middle ,ordovician lead-bearing rocks of ,illinois1 ,wisconsin1 and ,iowa1 but unfortunately correlated them with the ,niagaran1 while the ,middle ,devonian about ,columbus1 ,ohio1 and ,louisville1 ,kentucky1 he referred to the same horizon4 ,the ,galena-,niagaran error was corrected in #ahee1 but the ,devonian and ,mississippian ones remained unadjusted for a long time1 and in ,iowa until toward the close of the nineteenth century4 ,the ,geological ,column of the ,new ,york ,geologists of #ahdb-ahdc1 according to ,w4 ,w4 ,mather #ahdb4 ,quaternary system ,alluvial division4 ,quaternary division4 ,drift division4 ,tertiary system ,these strata are included in the next lower division4 ,long ,island division4 ,equals,new ,red the ,tertiary and system of ,upper ,secondary system ,cretaceous marls1 sands1 ,emmons and and clays of the coastal ,hall4 plain of ,new ,jersey4 ,trappean division4 ,the ,palisades ,red ,sandstone division4 ,coal system of ,mather1 and ,carboniferous system of ,hall4 ,old ,red system of ,catskill ,mountains of ,emmons2 ,catskill division of ,mather and ,hall2 and ,catskill group of ,vanuxem4 ,according to ,hall #ahdc1 and essentially ,vanuxem #ahdb4 ,chemung1 ,portage or ,nunda 7divided into ,cashaqua1 ,gardeau1 ,portage71 ,genesee1 ,erie division ,devonian ,tully1 ,hamilton 7divided into ,ludlowville2 ,encrinal1 ,moscow71 and ,marcellus4 ,corniferous1 ,onondaga1 ,schoharie1 ,helderberg series ,cauda-alli1 ,oriskany1 ,upper ,devonian-,silurian ,pentamerus1 ,encrinal1 ,delthyris1 ,pentamerus1 ,waterlime1 ,onondaga salt group4 ,ontario division ,silurian ,niagara1 ,clinton1 and ,medina4 ,oneida or ,shawangunk1 ,grey sandstone1 ,champlain division ,hudson ,river group1 ,utica1 ,trenton1 ,silurian-,ordovician-,upper ,black ,river including ,birdseye and ,cambrian ,chazy1 ,calciferous sandrock1 and ,potsdam4 ,according to ,emmons #ahdb1 ,mather #ahdc1 ,vanuxem #ahdb1 ,hall #ahdc4 ,taconic ,system ,ordovician ,granular quartz1 ,stockbridge limestone1 and ,lower ,cambrian ,magnesian slate1 and ,taconic slate4 ,primary or ,hypogene system ,metamorphic and ,primary rocks4 ,correlations with ,europe4--,the first effort toward correlating the ,new ,york system with those of ,europe was made by ,conrad in his ,notes on ,american ,geology in #ahci 7#ce1 #bdc74 ,here he compares it on faunal grounds with the ,silurian system4 ,a more sustained effort was that of ,hall in #ahdc 7#de1 #aeg71 when he said that the ,silurian of ,murchison was equal to the ,new ,york system and embraced the ,cambrian1 ,silurian1 and ,devonian1 which he considered as forming but one system4 ,hall in #ahdd and ,conrad earlier were erroneously regarding the ,middle ,devonian of ,new ,york 7,hamilton7 as 8an equivalent of the ,ludlow rocks of ,mr4 ,murchison0 7#dg1 #aah1 #ahdd74 ,in #ahdf ,e4 ,p4 ,de ,verneuil spent the summer in ,america with a view to correlating the formations of the ,new ,york system with those of ,europe4 ,at this time he had had a wide field experience in ,france1 ,germany1 and ,russia1 was president of the ,geological ,society of ,france1 and 8virtually the representative of ,european geology0 7#b1 #aec1 #ahdf74 ,hall says1 8,no other person could have presented so clear and perfect a coup d'oeil40 ,de ,verneuil's results were translated by ,hall and with his own comments were published in the ,journal in #ahdh and #ahdi under the title 8,on the ,parallelism of the ,paleozoic ,deposits of ,north ,america with those of ,europe40 ,de ,verneuil was especially struck with the complete development of ,american ,paleozoic deposits and said it was the best anywhere4 ,on the other hand1 he did not agree with the detailed arrangement of the formations in the various divisions of the ,new ,york system1 and ,hall admitted altogether too readily that the terms were proposed 8as a matter of concession1 and it is to be regretted that such an artificial classification was adopted40 ,de ,verneuil's correlations are as follows3 ,the ,lower ,silurian system begins with the ,potsdam1 the analogue of the ,obolus sandstone of ,russia and ,sweden4 ,the ,black ,river and ,trenton hold the position of the ,orthoceras limestones of ,sweden and ,russia1 while the ,utica and ,lorraine are represented by the ,graptolite beds of the same countries4 ,both correlations are in partial error4 ,he unites the ,chazy1 ,birdseye1 and ,black ,river in one series1 and in another the ,trenton1 ,utica1 and ,lorraine4 ,of species common to ,europe and ,america he makes out seventeen4 ,in the ,upper ,silurian system1 the ,oneida and ,shawangunk are taken out of the ,champlain division1 and1 with the ,medina1 are referred to the ,silurian1 along with all of the ,ontario division plus the ,lower ,helderberg4 ,the ,clinton is regarded as highest ,caradoc or as holding a stage between that and the ,wenlock4 ,the ,niagara group is held to be the exact equivalent of the ,wenlock1 8while the five inferior groups of the ,helderberg division represent the rocks of ,ludlow40 ,we now know that these ,helderberg formations are ,lower ,devonian in age4 ,de ,verneuil unites in one series the ,waterlime1 ,pentamerus1 ,delthyris1 ,encrinal1 and ,upper ,pentamerus4 ,of identical species there are forty common to ,europe and ,america4 ,the ,devonian system ,de ,verneuil begins1 8after much hesitation10 with the ,oriskany and certainly with the five upper members of ,hall's ,helderberg division1 all of the ,erie and the ,old ,red ,sandstone4 ,he also adjusts ,hall's error by placing in the ,devonian the ,upper ,cliff limestone of ,ohio and ,indiana1 regarded by the former as ,silurian4 ,the ,oriskany is correlated with the grauwackes of the ,rhine1 and the ,onondaga or ,corniferous with the lower ,eifelian4 ,cauda-galli1 ,schoharie1 and ,onondaga are united in one series2 ,marcellus1 ,hamilton1 ,tully1 and ,genesee in another2 and ,portage and ,chemung in a third4 ,of species common to ,europe and ,america there are thirty-nine4 ,the ,waverly of ,ohio and that near ,louisville1 ,kentucky1 which ,hall had called ,chemung1 ,de ,verneuil correctly refers to the ,carboniferous1 but to this ,hall does not consent4 ,de ,verneuil points out that there are thirty-one species in common between ,europe and ,america4 8,and as to plants1 the immense quantity of terrestrial species identical on the two sides of the ,atlantic1 proves that the coal was formed in the neighborhood of lands already emerged1 and placed in similar physical conditions40 ,an analysis of the ,paleozoic fossils of ,europe and ,america leads ,de ,verneuil to 8the conviction that identical species have lived at the same epoch in ,america and in ,europe1 that they have had nearly the same duration1 and that they succeeded each other in the same order40 ,this he states is independent of the depth of the seas1 and of 8the upheavings which have affected the surface of the globe40 ,the species of a period begin and drop out at different levels1 and toward the top of a system the whole takes on the character of the next one4 8,if it happens that in the two countries a certain number of systems1 characterized by the same fossils1 are superimposed in the same order1 whatever may be1 otherwise1 their thickness and the number of physical groups of which they are composed1 it is philosophical to consider these systems as parallel and synchronous40 ,because of the dominance of the sandstones and shales in eastern ,new ,york1 ,de ,verneuil holds that a land lay to the east4 ,the many fucoids and ripple-marks from the ,potsdam to the ,portage indicated to him shallow water and nearness to a shore4 ,the ,oldest ,geologic ,eras4--,we have seen in previous pages how the ,primitive rocks of ,arduino and of ,werner had been resolved1 at least in part1 into the systems of the ,paleozoic1 but there still remained many areas of ancient rocks that could not be adjusted into the accepted scheme4 ,one of the most extensive of these is in ,canada1 where the really ,primitive formations1 of granites1 gneisses1 schists1 and even undetermined sediments1 abound and are developed on a grander scale than elsewhere1 covering more than two million square miles and overlain unconformably by the ,paleozoic and later rocks4 ,the first to call attention to them was ,j4 ,i4 ,bigsby1 a medical staff officer of the ,british ,army1 in #ahba 7#c1 #bed74 ,it was1 however1 ,william ,e4 ,logan 7#agih-ahge71 the 8father of ,canadian geology10 who first unravelled their historical sequence4 ,at first he also called them ,primary1 but after much work he perceived in them parallel structures and metamorphosed sediments1 underlain by and associated with pink granites4 ,for the oldest masses1 essentially the granites1 he proposed the term ,laurentian system 7#ahec1 #ahfc7 and for the altered and deformed strata1 the name ,huronian series 7#aheg1 #ahfc74 ,overlying these unconformably was a third series1 the copper-bearing rocks4 ,since his day a great host of ,canadian and ,american geologists have labored over this1 the most intricate of all geology1 and now we have the following tentative chronology 7,schuchert and ,barrell1 #ch1 #a1 #aiad73 ,late ,proterozoic era4 ,keweenawan1 ,animikian and ,huronian periods4 ,early ,proterozoic era4 ,sudburian period or older ,huronian4 ,archeozoic era4 ,grenville series1 etc4 ,cosmic history4 ,the ,taconic ,system ,resurrected4 ,the ,taconic system was first announced by ,ebenezer ,emmons in #ahda1 and clearly defined in #ahdb4 ,it started the most bitter and most protracted discussion in the annals of ,american geology4 ,after ,emmons's subsequent publications had put the ,taconic system through three phases1 ,barrande of ,bohemia in #ahfj-ahfc shed a great deal of new and correct light upon it1 affirming in a series of letters to ,billings that the ,taconic fossils are like those of his ,primordial system1 or what we now call the ,middle ,cambrian 7#ca1 #baj1 #ahfa1 et seq474 ,in a series of articles published by ,s4 ,w4 ,ford in the ,journal between #ahga and #ahhf1 there was developed the further new fact that in ,rensselaer and ,columbia counties1 ,new ,york1 the so-called ,hudson ,river group abounds in 8,primordial0 fossils wholly unlike those of the ,potsdam1 and which ,ford later on spoke of as belonging to 8,lower ,potsdam0 time4 ,james ,d4 ,dana entered the field of the ,taconic area in #ahga and demonstrated that the system also abounds in ,ordovician fossiliferous formations4 ,then came the far-reaching work of ,charles ,d4 ,walcott1 beginning in #ahhf1 which showed that all through eastern ,new ,york and into northern ,vermont the ,hudson ,river group and the ,taconic system abound not only in ,ordovician but also in ,cambrian fossils4 ,finally in #ahhh ,dana presented a ,brief ,history of ,taconic ,ideas1 and laid away the system with these words 7#cf1 #bg73 8,it is almost fifty years since the ,taconic system made its abrupt entrance into geological science4 ,notwithstanding some good points1 it has been through its greater errors1 long a hindrance to progress here and abroad 444 ,but1 whether the evil or the good has predominated1 we may now hope1 while heartily honoring ,professor ,emmons for his earnest geological labors and his discoveries1 that ,taconic ideas may be allowed to be and remain part of the past40 ,as an epitaph ,dana placed over the remains of the ,taconic system the black-faced numerals #ahda-ahhh4 ,that the remains of the system1 however1 and the term ,taconic are still alive and demanding a rehearing is apparent to all interested stratigraphers4 ,this is not the place to set the matter right1 and all that can be done at the present time is to point out what are the things that still keep alive ,emmons's system4 ,in the typical area of the ,taconic system1 i4 e41 in ,rensselaer ,county1 ,emmons in #ahdd-ahdf produced the fossils ,atops trilineatus and ,elliptocephala asaphoides4 ,s4 ,w4 ,ford1 as stated above1 later produced from the same general area many other fossils that he demonstrated to be older than the ,potsdam sandstone4 ,to this time he gave the name of ,lower ,potsdam1 thus proving on paleontological grounds that at least some part of the ,taconic system is older than the ,new ,york system1 and therefore older than the ,hudson ,river group of ,ordovician age4 ,in #ahhh ,walcott presented his conclusions in regard to the sequence of the strata in the typical ,taconic area and to the north and south of it4 ,he collected ,lower ,cambrian fossils at more than one hundred localities 8within the typical ,taconic area10 and said that the thickness of his 8terrane ,no4 #e0 or 8,cambrian 7,georgia710 now referable to the ,lower ,cambrian1 is 8#ad1jjj feet or more40 ,he demonstrated that the ,lower ,cambrian is infolded with the ,lower and ,middle ,ordovician1 and confirmed ,emmons's statement that the former rests upon his ,primary or ,pre-,cambrian masses4 ,elsewhere1 he writes3 8,to the west of the ,taconic range the section passes down through the limestone 7#c7 of ,lower and ,middle ,ordovician age to the hydromica schists 7#b7 whose age may also be of early ,ordovician1 and thence to the great development of slates and shales with their interbedded sparry limestones1 calciferous and arenaceous strata1 all of which contain more or less of the ,olenellus 444 fauna40 ,he then knew thirty-five species in ,washington ,county1 ,new ,york 7#ce1 #dja1 #ahhh74 ,finally in #aiae ,walcott said that in the ,cordilleran area of ,america there was a movement that brought about changes 8in the sedimentation and succession of the faunas which serve to draw a boundary line between the ,lower and ,middle ,cambrian series4444 ,the length of this period of interruption must have been considerable 444 and when connection with the ,pacific was resumed a new fauna that had been developing in the ,pacific was then introduced into the ,cordilleran sea and constituted the ,middle ,cambrian fauna4 ,the change in the species from the ,lower to the ,middle ,cambrian fauna is very great40 ,he then goes on to show that in the ,appalachian geosyncline there was another movement that shut out the ,middle ,cambrian ,paradoxides fauna of the ,atlantic realm from this trough1 and all deposition as well4 ,conclusions4--,accordingly it appears that everywhere in ,america the ,lower ,cambrian formations are separated by a land interval of long duration from those of ,middle ,cambrian time4 ,these formations therefore unite into a natural system of rocks or a period of time4 ,between ,middle and ,upper ,cambrian time1 however1 there appears to be a complete transition in the ,cordilleran trough1 binding these two series of deposits into one natural or diastrophic system4 ,hence the writer proposes that the ,lower ,cambrian of ,america be known as the ,taconic system4 ,the ,middle and ,upper ,cambrian series can be continued for the present under the term ,cambrian system1 a term1 however1 that is by no means in good standing for these formations1 as will be demonstrated under the discussion of the ,silurian controversy4 ,the ,silurian ,controversy4 ,just as in ,america the base of the ,paleozoic was involved in a protracted controversy1 so in ,england the ,cambrian-,silurian succession was a subject of long debate between ,sedgwick and ,murchison1 and among the succeeding geologists of ,europe4 ,the history of the solution is so well and justly stated in the ,journal by ,james ,d4 ,dana under the title 8,sedgwick and ,murchison3 ,cambrian and ,silurian0 7#ci1 #afg1 #ahij71 and by ,sir ,archibald ,geikie in his ,text-book of ,geology1 #aijc1 that all that is here required is to briefly restate it and to bring the solution up to date4 ,adam ,sedgwick 7#aghe-ahgc7 and ,r4 ,i4 ,murchison 7#agib-ahga7 each began to work in the areas of ,cambria 7,wales7 and ,siluria 7,england7 in #ahca1 but the terms ,cambrian and ,silurian were not published until #ahce4 ,murchison was the first to satisfactorily work out the sequence of the ,silurian system because of the simpler structural and more fossiliferous condition of his area4 ,sedgwick1 on the other hand1 had his academic duties to perform at ,cambridge ,university1 and being an older and more conservative man1 delayed publishing his final results1 because of the further fact that his area was far more deformed and less fossiliferous4 ,in #ahcd they were working in concert in the ,silurian area1 and ,sedgwick said3 8,i was so struck by the clearness of the natural sections and the perfection of his workmanship that ,i received1 ,i might say1 with implicit faith everything which he then taught me4444 ,the whole #8,silurian system' was by its author placed above the great undulating slate-rocks of ,south ,wales40 ,at that time ,murchison told ,sedgwick that the ,bala group of the latter1 now known to be in the middle of the ,lower ,silurian1 could not be brought within the limits of the ,silurian system1 and added1 8,i believe it to plunge under the true ,llandeilo-flags10 now placed next below the ,bala and above the ,arenig1 which at the present is regarded as at the base of the ,ordovician4 ,the ,silurian system was defined in print by ,murchison in ,july1 #ahce1 the ,upper ,silurian embracing the ,ludlow and ,wenlock1 while the ,lower ,silurian was based on the ,caradoc and ,llandeilo4 ,murchison's monumental work1 ,the ,silurian ,system1 of #ajj pages and many plates of fossils1 appeared in #ahch4 ,the ,cambrian system was described for the first time by ,sedgwick in ,august1 #ahce1 but the completed work--a classic in geology--,synopsis of the ,classification of the ,british ,palozoic ,rocks1 along with ,m',coy's ,descriptions of ,british ,palozoic ,fossils1 did not appear until #aheb-ahee4 ,sedgwick's original ,upper ,cambrian included the greater part of the chain of the ,berwyns1 where he said it was connected with the ,llandeilo flags of the ,silurian4 ,the ,middle ,cambrian comprised the higher mountains of ,crnarvonshire and ,merionethshire1 and the ,lower ,cambrian was said to occupy the southwest coast of ,crnarvonshire1 and to consist of chlorite and mica schists1 and some serpentine and granular limestone4 ,in #ahec it was seen that the fossiliferous ,upper ,cambrian included the ,arenig1 ,llandeilo1 ,bala1 ,caradoc1 ,coniston1 ,hirnant1 and ,lower ,llandovery4 ,on the other hand1 it was not until long after ,murchison and ,sedgwick passed away that the ,middle and ,lower ,cambrian were shown to have fossils1 but few of those that characterize what is now called ,lower1 ,middle1 and ,upper ,cambrian time4 ,not until long after the original announcement of the ,cambrian system did ,sedgwick become aware 8of the unfortunate mischief-involving fact0 that the most fossiliferous portion of the ,cambrian--the ,upper ,cambrian--and at that time the only part yielding determinable fossils1 when compared with the ,lower ,silurian was seen to be an equivalent formation but with very different lithologic conditions4 ,he began to see in #ahdb that his ,cambrian was in conflict with the ,silurian system1 and four years later there were serious divergencies of views between himself and ,murchison4 ,the climax of the controversy was attained in #aheb1 when ,sedgwick was extending his ,cambrian system upwards to include the ,bala1 ,llandeilo1 and ,caradoc1 a proceeding not unlike that of ,murchison1 who earlier had been extending his ,silurian downward through all of the fossiliferous ,cambrian to the base of the ,lingula flags4 ,dana in his review of the ,silurian-,cambrian controversy states3 8,the claim of a worker to affix a name to a series of rocks first studied and defined by him cannot be disputed40 ,we have seen that ,murchison had priority of publication in his term ,silurian over ,sedgwick's ,cambrian1 but that in a complete presentation1 both stratigraphically and faunally1 the former had years of prior definition4 ,what has even more weight is that geologists nearly everywhere had accepted ,murchison's ,silurian system as founded upon the ,lower and ,upper ,silurian formations4 ,a nomenclature once widely accepted is almost impossible to dislodge4 ,however1 in regard to the controversy it should not be forgotten that it was only ,murchison's ,lower ,silurian that was in conflict with ,sedgwick's ,upper ,cambrian4 ,as for the rest of the ,cambrian1 that was not involved in the controversy4 ,dana goes on to state that science may accept a name1 or not1 according as it is1 or is not1 needed4 ,in the progress of geology1 he thought that the time had finally been reached when the name ,cambrian was a necessity1 and he included both ,cambrian and ,silurian in the geological record4 ,the 8,silurian10 however1 included the ,lower and ,upper ,silurian--not one system of rocks1 but two4 ,it is now twenty-seven years since ,dana came to this conclusion1 at a time when it was believed that there was more or less continuous deposition not only between the formations of a system but between the systems themselves as well4 ,to-day many geologists hold that in the course of time the oceans pulsate back and forth over the continents1 and accordingly that the sequence of marine sedimentation in most places must be much broken1 and to-day we know that the breaks or land intervals in the marine record are most marked between the eras1 and shorter between all or at least most of the periods4 ,furthermore1 in ,north ,america1 we have learned that the breaks between the systems are most marked in the interior of the continent and less so on or toward its margins4 ,hardly any one now questions the fact of a long land interval between the ,lower ,silurian and ,upper ,silurian in ,england1 and it is to ,sedgwick's credit that he was the first to point out this fact and also the presence of an unconformity4 ,it therefore follows that we cannot continue to use ,silurian system in the sense proposed by ,murchison1 since it includes two distinct systems or periods4 ,dana1 in the last edition of his ,manual of ,geology 7#ahie71 also recognizes two systems1 but curiously he saw nothing incongruous in calling them 8,lower ,silurian era0 and 8,upper ,silurian era40 ,it certainly is not conducive to clear thinking1 however1 to refer to two systems by the one name of ,silurian and to speak of them individually as ,lower and ,upper ,silurian1 thus giving the impression that the two systems are but parts of one--the ,silurian4 ,each one of the parts has its independent faunal and physical characters4 ,we must digress a little here and note the work of ,joachim ,barrande 7#agii-ahhc7 in ,bohemia4 ,in #ahdf he published a short account of the 8,silurian system0 of ,bohemia1 dividing it into tages lettered ,c to ,h4 ,between #aheb and #ahhc he issued his 8,systme ,silurien du ,centre de la ,bohme10 in eighteen quarto volumes with #eefh pages of text and #gih plates of fossils--a monumental work unrivalled in paleontology4 ,in the first volume the geology of ,bohemia is set forth1 and here we see that tages ,a and ,b are ,azoic or pre-,cambrian1 and ,c to ,h make up his ,silurian system4 ,etage ,c has his 8,primordial fauna10 now known to be of ,paradoxides or ,middle ,cambrian time1 while ,d is ,lower ,silurian1 ,e is ,upper ,silurian1 ,f is ,lower ,devonian1 and ,g and ,h are ,middle ,devonian4 ,from this it appears that ,barrande's ,silurian system is far more extensive than that of ,murchison1 embracing twice as many periods as that of ,england and ,wales4 ,about #ahgi there was in ,england a nearly general agreement that ,cambrian should embrace ,barrande's ,primordial or ,paradoxides faunas1 and in the ,north ,wales area be continued up to the top of the ,tremadoc slates4 ,to-day we would include ,middle and ,upper ,cambrian4 ,lower ,cambrian in the sense of containing the ,olenellus faunas was then unknown in ,great ,britain4 ,lapworth1 recognizing the distinctness of the ,lower ,silurian as a system1 proposed in #ahgi to recognize it as such1 and named it ,ordovician1 restricting ,silurian to ,murchison's ,upper ,silurian4 ,this term has not been widely used either in ,great ,britain or on the ,continent1 but in the last twenty years has been accepted more and more widely in ,america4 ,even here1 however1 it is in direct conflict with the term ,champlain1 proposed by the ,new ,york ,state ,geologist in #ahdb4 ,in #ahig the ,international ,geological ,congress published ,e4 ,renevier's ,chronographie ,gologique1 wherein we find the following3 ,upper or ,silurian ,ludlowian 7,murchison ,silurian ,period4 7,murchison1 restricted1 #ahci74 #ahce74 ,wenlockian 7,murchison #ahci74 ,landoverian 7,murchison74 ,middle or ,ordovician ,caradocian 7,murchison 7,lapworth #ahgi74 #ahci74 ,landeilian 7,murchison #ahci74 ,arenigian 7,sedgwick #ahdg74 ,lower or ,cambrian 7,sedgwick1 restricted1 ,potsdamian 7,emmons #ahch74 #ahce74 ,menevian 7,salter and ,hicks #ahfe74 ,georgian 7,hitchcock #ahfa74 ,regarding this period1 which1 by the way1 is not very unlike that of ,barrande1 ,renevier remarks that it is 8as important as the ,cretaceous or the ,jurassic4 ,lapworth even gives it a value of the first order equal to the ,protozoic era40 ,in the above there is an obvious objection in the double usage of the term ,silurian1 and this difficulty was met later on in ,lapparent's ,trait by the proposal to substitute ,gothlandian for ,silurian4 ,of this change ,geikie remarks3 8,such an arrangement 444 might be adopted if it did not involve so serious an alteration of the nomenclature in general use40 ,on the other hand1 if diastrophism and breaks in the stratigraphic and faunal sequence are to be the basis for geologic time divisions1 we cannot accept the above scheme1 for it recognizes but one period where there are at least four in nature4 ,conclusions4--,we have arrived at a time when our knowledge of the stratigraphic and faunal sequence1 plus the orogenic record as recognized in the principle of diastrophism1 should be reflected in the terminology of the geologic time-table4 ,it would be easy to offer a satisfactory nomenclature if we were not bound by the law of priority in publication1 and if no one had the geologic chronology of his own time ingrained in his memory4 ,in addition1 the endless literature1 with its accepted nomenclature1 bars our way4 ,therefore with a view of creating the least change in geologic nomenclature1 and of doing the greatest justice to our predecessors that the present conditions of our knowledge will allow1 the following scheme is offered3 ,silurian period4 ,llandovery to top of ,ludlow in ,europe4 ,alexandrian-,cataract-,medina to top of ,manlius in ,america4 ,champlain 7#ahdb7 or ,ordovician 7#ahgi7 period4 ,arenig to top of ,caradoc in ,europe4 ,beekmantown to top of ,richmondian in ,america4 ,cambrian period4 ,in the ,atlantic realm1 begins with the ,paradoxides1 and in the ,pacific1 with the ,bathyuriscus and ,ogygopsis faunas4 ,the close is involved in ,ulrich's provisionally defined ,ozarkian system4 ,when the latter is established1 the ,ozarkian period will hold the time between the ,ordovician and the ,cambrian4 ,taconic period4 ,for the world-wide ,olenellus or ,mesonacid faunas4 ,paleogeography4 ,when geologists began to perceive the vast significance of ,hutton's doctrine that 8the ruins of an earlier world lie beneath the secondary strata10 and that great masses of bedded rocks are separated from one another by periods of mountain making and by erosion intervals1 it was natural for them to look for the lands that had furnished the debris of the accumulated sediments4 ,in this way paleogeography had its origin1 but it was at first of a descriptive and not of a cartographic nature4 ,the word paleogeography was proposed by ,t4 ,sterry ,hunt in #ahgb in a paper entitled 8,the ,paleogeography of the ,north ,american ,continent10 and published in the ,journal of the ,american ,geographical ,society for that year4 ,it has to do1 he says1 with the 8geographical history of these ancient geological periods40 ,it was again prominently used by ,robert ,etheridge in his presidential address before the ,geological ,society of ,london in #ahha4 ,since ,canu's use of the term in #ahif1 it has been frequently seen in print1 and now is generally adopted to signify the geography of geologic time4 ,the ,french were the first to make paleogeographic maps1 and ,jules ,marcou relates in #ahff that ,elie de ,beaumont1 as early as ,march1 #ahca1 in his course in the ,college of ,france and at the ,paris ,school of ,mines1 used to outline the relation of the lands and the seas in the center of ,europe at the different great geologic periods4 ,his first printed paleogeographic map appeared in #ahcc1 and was of early ,tertiary time4 ,other maps by ,beaumont were published by ,beudant in #ahda-ahdb4 ,the ,sicilian geologist ,gemmellaro published six maps of his country in #ahcd1 and the ,englishman ,de ,la ,beche had one in the same year4 ,in ,america the first to show such maps was ,arnold ,guyot in his ,lowell lectures of #ahdh4 ,james ,d4 ,dana published three in the #ahfc edition of his ,manual of ,geology4 ,of world paleogeographic maps1 ,jules ,marcou produced the first of ,jurassic time1 publishing it in ,france in #ahff1 but the most celebrated of these early attempts was the one by ,neumayr published in #ahhc in connection with his ,ueber klimatische ,zonen whrend der ,jura- und ,kreidezeit4 ,the first geologist to produce a series of maps showing the progressive geologic geography of a given area was ,jukes-,brown1 who in the volume entitled 8,the ,building of the ,british ,isles10 #ahhh1 included fifteen such maps4 ,karpinsky published fourteen maps of ,russia1 and in #ahif ,canu in his ,essai de palogographie has fifty-seven of ,france and ,belgium4 ,lapparent's ,trait of #aijf is famous for paleogeographic maps1 for he has twenty-three of the world1 thirty-four of ,europe1 twenty-five of ,france1 and ten taken from other authors4 ,schuchert in #aiaj published fifty-two to illustrate the paleogeography of ,north ,america1 and also gave an extended list of such published maps4 ,another article on the subject is by ,th4 ,arldt1 8,zur ,geschichte der ,palogeographischen ,rekonstructionen10 published in #aiad4 ,edgar ,dacqu in #aiac also produced a list in his ,palogeographischen ,karten1 and two years later appeared his book of #ejj pages1 ,grundlagen und ,methoden der ,palogeographie1 where the entire subject is taken up in detail4 ,conclusions4--,since #ahcc there have been published not less than #ejj different paleogeographic maps1 and of this number about #baj relate to ,north ,america4 ,nevertheless paleogeography is still in its infancy1 and most maps embrace too much geologic time1 all of them tens of thousands1 and some of them millions of years4 ,the geographic maps of the present show the conditions of the strand-lines of to-day1 and those made fifty years ago have to be revised again and again if they are to be of value to the mariner and merchant4 ,therefore in our future paleogeographic maps the tendency must ever be toward smaller amounts of geologic time1 if we are to show the actual relation of water to land and the movements of the periodic floodings4 ,moreover1 the ancient shore lines are all more or less hypothetic and are drawn in straight or sweeping curves1 unlike modern strands with their bays1 deltas1 and headlands1 and the ancient lands are featureless plains4 ,we must also pay more attention to the distribution of brackish- and fresh-water deposits4 ,the periodically rising mountains will be the first topographic features to be shown upon the ancient lands1 and then more and more of the drainage and the general climatic conditions must be portrayed4 ,in the seas1 depth1 temperature1 and currents are yet to be deciphered4 ,finally1 other base maps than those of the geography of to-day will have to be made1 allowing for the compression of the mountainous areas1 if we are to show the true geographic configurations of the lands and seas of any given geologic time4 ,paleometeorology4 ,in accordance with the ,laplacian theory1 announced at the beginning of the nineteenth century1 all of the older geologists held that the earth began as a hot star1 and that in the course of time it slowly cooled and finally attained its present zonal cold to tropical climatic conditions4 ,that the earth had very recently passed through a much colder climate1 a glacial one1 came into general acceptance only during the latter half of the previous century4 ,rise4--,our knowledge of glacial climates had its origin in the ,alps1 that wonderland of mountains and glaciers4 ,the rise of this knowledge in the ,alps is told in a charming and detailed manner by that erratic ,french-,american geologist1 ,jules ,marcou 7#ahbd-ahih71 in his ,life1 ,letters1 and ,works of ,louis ,agassiz1 #ahif4 ,he relates that the ,alpine chamois hunter ,perraudin in #ahae directed the attention of the engineer ,de ,charpentier to the fact 8that the large boulders perched on the sides of the ,alpine valleys were carried and left there by glaciers40 ,for a long time the latter thought the conclusion extravagant1 and in the meantime ,perraudin told the same thing to another engineer1 ,venetz4 ,he1 in #ahbi1 convinced of the correctness of the chamois hunter's views1 presented the matter before the ,swiss naturalists then meeting at ,st4 ,bernard's4 ,venetz 8told the ,society that his observations led him to believe that the whole ,valais has been formerly covered by an immense glacier and that it even extended outside of the canton1 covering all the ,canton de ,vaud1 as far as the ,jura ,mountains1 carrying the boulders and erratic materials1 which are now scattered all over the large ,swiss valley40 ,eight years earlier1 in #ahba1 similar views had been presented by the same modest naturalist before the ,helvetic ,society1 but it was not until #ahcc that ,de ,charpentier found the manuscript and had it published4 ,venetz's conclusions were that all of the glaciers of the ,bagnes valley 8have very recognizable moraines1 which are about a league from the present ice40 8,the moraines 444 date from an epoch which is lost in the night of time40 ,then in #ahcd ,de ,charpentier read a paper before the same society1 meeting at ,lucerne4 8,seldom1 if ever1 has such a small memoir so deeply excited the scientific world4 ,it was received at first with incredulity and even scorn and mockery1 ,agassiz being among its opponents40 ,the paper was published in #ahce1 first at ,paris1 then at ,geneva1 and finally in ,germany4 ,it 8attracted much attention1 and the smile of incredulity with which it was received when read at ,lucerne soon changed into a desire to know more about it40 ,louis ,agassiz 7#ahjg-ahgc71 who had long been acquainted with his countryman1 ,de ,charpentier1 spent several months with him in #ahcf1 and together they studied the glaciers of the ,alps4 ,agassiz was at first 8adverse to the hypothesis1 and did not believe in the great extension of glaciers and their transportation of boulders1 but on the contrary1 was a partisan of ,lyell's theory of transport by icebergs and ice-cakes 444 but from being an adversary of the glacial theory1 he returned to ,neuchtel an enthusiastic convert to the views of ,venetz and ,de ,charpentier4444 ,with his power of quick perception1 his unmatched memory1 his perspicacity and acuteness1 his way of classifying1 judging and marshalling facts1 ,agassiz promptly learned the whole mass of irresistible arguments collected patiently during seven years by ,de ,charpentier and ,venetz1 and with his insatiable appetite and that faculty of assimilation which he possessed in such a wonderful degree1 he digested the whole doctrine of the glaciers in a few weeks40 ,in ,july1 #ahcg1 ,agassiz presented as his presidential address before the ,helvetic ,society his memorable 8,discours de ,neuchtel10 which was 8the starting point of all that has been written on the ,ice-age10--a term coined at the time by his friend ,schimper1 a botanist4 ,the first part of this address is reprinted in ,french in ,marcou's book on ,agassiz4 ,the address was received with astonishment1 much incredulity1 and indifference4 ,among the listeners was the great ,german geologist ,von ,buch1 who 8was horrified1 and with his hands raised towards the sky1 and his head bowed to the distant ,bernese ,alps1 exclaimed3 #8,o ,sancte de ,saussure1 ora pro nobis6'0 ,even ,de ,charpentier 8was not gratified to see his glacial theory mixed with rather uncalled for biological problems1 the connection of which with the glacial age was more than problematic40 ,agassiz was then a ,cuvierian catastrophist and creationist1 and advanced the idea of a series of glacial ages to explain the destruction of the geologic succession of faunas6 ,curiously1 this theory was at once accepted by the ,american paleontologist ,t4 ,a4 ,conrad 7#ce1 #bci1 #ahci74 ,the classics in glacial geology are ,agassiz's ,etudes sur les ,glaciers1 #ahdj1 and ,de ,charpentier's ,essai sur les ,glaciers1 #ahda4 ,of the latter book1 ,marcou states that it has been said3 8,it is impossible to be truly a geologist without having read and studied it40 ,in the ,english language there is ,tyndall's ,glaciers of the ,alps1 #ahfj4 ,the progress of the ideas in regard to ,pleistocene glaciation is presented in the following chapter by ,h4 ,e4 ,gregory4 ,older ,glacial ,climates4--,hardly had the ,pleistocene glacial climate been proved1 when geologists began to point out the possibility of even earlier ones4 ,an enthusiastic ,scotch writer1 ,sir ,andrew ,ramsay1 in #ahee described certain late ,paleozoic conglomerates of middle ,england1 which he said were of glacial origin1 but his evidence1 though never completely gainsaid1 has not been generally accepted4 ,in the following year1 an ,englishman1 ,doctor ,w4 ,t4 ,blanford1 said that the ,talchir conglomerates of central and southern ,india were of glacial origin1 and since then the evidence for a ,permian glacial climate has been steadily accumulating4 ,africa is the land of tillites1 and here in #ahgj ,sutherland pointed out that the conglomerates of the ,karroo formation were of glacial origin4 ,australia also has ,permian glacial deposits1 and they are known widely in eastern ,brazil1 the ,falkland ,islands1 the vicinity of ,boston1 and elsewhere4 ,so convincing is this testimony that all geologists are now ready to accept the conclusion that a glacial climate was as wide-spread in early ,permian time as was that of the ,pleistocene4#c ,in ,south ,africa1 beneath the marine ,lower ,devonian1 occurs the ,table ,mountain series1 #ejjj feet thick4 ,the series is essentially one of quartzites1 with zones of shales or slates and with striated pebbles up to #ae inches long4 ,the latter occur in pockets and seem to be of glacial origin4 ,there are here no typical tillites1 and no striated undergrounds have so far been found4 ,while the evidence of the deposits appears to favor the conclusion that the ,table ,mountain strata were laid down in cold waters with floating ice derived from glaciers1 it is as yet impossible to assign these sediments a definite geologic age4 ,they are certainly not younger than the ,lower ,devonian1 but it has not yet been established to what period of the early ,paleozoic they belong4 ,in southeastern ,australia occur tillites of wide distribution that lie conformably beneath1 but sharply separated from the fossiliferous marine ,lower ,cambrian strata4 ,david 7#aijg71 ,howchin 7#aijh71 and other ,australian geologists think they are of ,cambrian time1 but to the writer they seem more probably late ,proterozoic in age4 ,in arctic ,norway ,reusch discovered unmistakable tillites in #ahia1 and this occurrence was confirmed by ,strahan in #ahig4 ,it is not yet certainly known what their age is1 but it appears to be late ,proterozoic rather than early ,paleozoic4 ,other undated ,proterozoic tillites occur in ,china 7,willis and ,blackwelder #aijg71 ,africa 7,schwarz #aijf71 ,india 7,vredenburg #aijg71 ,canada 7,coleman #aijh71 and possibly in ,scotland4 ,the oldest known tillites are described by ,coleman in #aijg1 and occur at the base of the ,lower ,huronian or in early ,proterozoic time4 ,they extend across northern ,ontario for #ajjj miles1 and from the north shore of ,lake ,huron northward for #gej miles4 ,fossils as ,climatic ,indexes4--,paleontologists have long been aware that variations in the climates of the past are indicated by the fossils1 and ,neumayr in #ahhc brought the evidence together in his study of climatic zones mentioned elsewhere4 ,plants1 and corals1 cephalopods1 and foraminifers among marine animals1 have long been recognized as particularly good 8life thermometers40 ,in fact1 all fossils are climatic indicators to some extent1 and a good deal of evidence concerning paleometeorology has been discerned in them4 ,this evidence is briefly stated in the paper by ,schuchert already alluded to1 and in ,w4 ,d4 ,matthew's ,climate and ,evolution1 #aiae4 ,sediments as ,climatic ,indexes4--,johannes ,walther in the third part of his ,einleitung--,lithogenesis der ,gegenwart1 #ahid--;is the first one to decidedly direct attention to the fact that the sediments also have within themselves a climatic record4 ,in ,america ,joseph ,barrell has since #aijg written much on the same subject4 ,on the other hand1 the periodic floodings of the continents by the oceans1 and the making of mountains1 due to the periodic shrinkage of the earth1 as expressed in ,t4 ,c4 ,chamberlin's principle of diastrophism and in his publications since #ahig1 are other criteria for estimating the climates of the past4 ,conclusions4--,in summation of this subject ,schuchert says3 8,the marine #8life thermometer' indicates vast stretches of time of mild to warm and equable temperatures1 with but slight zonal differences between the equator and the poles4 ,the great bulk of marine fossils are those of the shallow seas1 and the evolutionary changes recorded in these #8medals of creation' are slight throughout vast lengths of time that are punctuated by short but decisive periods of cooled waters and great mortality1 followed by quick evolution1 and the rise of new stocks4 ,the times of less warmth are the miotherm and those of greater heat the pliotherm periods of ,ramsay4 ,on the land the story of the climatic changes is different1 but in general the equability of the temperature simulates that of the oceanic areas4 ,in other words1 the lands also had long-enduring times of mild to warm climates4 ,into the problem of land climates1 however1 enter other factors that are absent in the oceanic regions1 and these have great influence upon the climates of the continents4 ,most important of these is the periodic warm-water inundation of the continents by the oceans1 causing insular climates that are milder and moister4 ,with the vanishing of the floods somewhat cooler and certainly drier climates are produced4 ,the effects of these periodic floods must not be underestimated1 for the ,north ,american continent was variably submerged at least seventeen times1 and over an area of from #aed1jjj to #d1jjj1jjj square miles4 ,when to these factors is added the effect upon the climate caused by the periodic rising of mountain chains1 it is at once apparent that the lands must have had constantly varying climates4 ,in general the temperature fluctuations seem to have been slight1 but geographically the climates varied between mild to warm pluvial1 and mild to cool arid4 ,the arid factor has been of the greatest import to the organic world of the lands4 ,further1 when to all of these causes is added the fact that during emergent periods the formerly isolated lands were connected by land bridges1 permitting intermigration of the land floras and faunas1 with the introduction of their parasites and parasitic diseases1 we learn that while the climatic environment is of fundamental importance it is not the only cause for the more rapid evolution of terrestrial life4444 ,briefly1 then1 we may conclude that the markedly varying climates of the past seem to be due primarily to periodic changes in the topographic form of the earth's surface1 plus variations in the amount of heat stored by the oceans4 ,the causation for the warmer interglacial climates is the most difficult of all to explain1 and it is here that factors other than those mentioned may enter4 ,granting all this1 there still seems to lie back of all these theories a greater question connected with the major changes in paleometeorology4 ,this is3 ,what is it that forces the earth's topography to change with varying intensity at irregularly rhythmic intervals8444 ,are we not forced to conclude that the earth's shape changes periodically in response to gravitative forces that alter the body-form80 ,evolution4 ,modern evolution1 or the theory of life continuously descending from life with change1 may be said to have had its first marked development in ,comte de ,buffon 7#agjg-aghh71 a man of wealth and station1 yet an industrious compiler1 a brilliant writer1 and a popularizer of science4 ,he was not1 however1 a true scientific investigator1 and his monument to fame is his ,histoire ,naturelle1 in forty-four volumes1 #agdi-ahjd4 ,a4 ,s4 ,packard in his book on ,lamarck1 his ,life and ,work1 #aija1 concludes in regard to ,buffon as follows3 8,the impression left on the mind1 after reading ,buffon1 is that even if he threw out these suggestions and then retracted them1 from fear of annoyance or even persecution from the bigots of his time1 he did not himself always take them seriously1 but rather jotted them down as passing thoughts4444 ,they appeared thirty-four years before ,lamarck's theory1 and though not epoch-making1 they are such as will render the name of ,buffon memorable for all time40 ,chevalier de ,lamarck 7#agdd-ahbi7 may justly be regarded as the founder of the doctrine of modern evolution4 ,previous to #agid he was a believer in the fixity of species1 but by #ahjj he stood definitely in favor of evolution4 ,locy in his ,biology and its ,makers1 #aijh1 states his theories in the following simplified form3 8,variations of organs1 according to ,lamarck1 arise in animals mainly through use and disuse1 and new organs have their origin in a physiological need4 ,a new need felt by the animal due to new conditions in its life1 or the environment expresses itself on the organism1 stimulating growth and adaptations in a particular direction40 ,to ,lamarck1 8inheritance was a simple1 direct transmission of those superficial changes that arise in organs within the lifetime of an individual owing to use and disuse40 ,this part of his theory has come to be known as 8the inheritance of acquired characters40 ,georges ,cuvier 7#agfi-ahcb71 a peer of ,france1 was a decided believer in the fixity of species and in their creation through divine acts4 ,in #agif he began to see that among the fossils so plentiful about ,paris many were of extinct forms1 and later on that there was a succession of wholly extinct faunas4 ,this at first puzzling phenomenon he finally came to explain by assuming that the earth had gone through a series of catastrophes1 of which the ,deluge was the most recent but possibly not the last4 ,with each catastrophe all life was blotted out1 and a new though improved set of organisms was created by divine acts4 ,the ,cuvierian theory of catastrophism was widely accepted during the first half of the nineteenth century1 and in ,america ,louis ,agassiz was long its greatest exponent4 ,it was this theory and the dominance of the brilliant ,cuvier1 not only in science but socially as well1 that blotted out the far more correct views of the more philosophical ,lamarck1 who held that life throughout the ages had been continuous and that through individual effort and the inheritance of acquired characters had evolved the wonderful diversity of the present living world4 ,in #ahcj there was a public debate at ,paris between ,cuvier and ,geoffroy ,saint-,hilaire1 the one holding to the views of the fixity of species and creation1 the other that life is continuous and evolves into better adapted forms4 ,cuvier1 a gifted speaker and the greatest debater zoology ever had1 with an extraordinary memory that never failed him1 defeated ,saint-,hilaire in each day's debate1 although the latter was in the right4 ,a book that did a great deal to prepare the ,english-speaking people for the coming of evolution was 8,vestiges of ,creation10 published in #ahdd by an unknown author4 ,in ,darwin's opinion1 8the work1 from its powerful and brilliant style 444 has done excellent service 444 in thus preparing the ground for the reception of analogous views40 ,this book was recommended to the readers of the ,journal 7#dh1 #cie1 #ahde7 with the editorial remark that 8we cannot subscribe to all of the author's views40 ,we can probably best illustrate the opinions of ,americans on the question of evolution just before the appearance of ,darwin's great work by directing attention to ,james ,d4 ,dana's ,thoughts on ,species 7#bd1 #cje1 #aheg74 ,after reading this article and others of a similar nature by ,agassiz1 one comes to the opinion that unconsciously both men are proving evolution1 but consciously they are firm creationists4 ,it is astonishing that with their extended and minute knowledge of living organisms and their philosophic type of mind neither could see the true significance of the imperceptible transitions between some species1 which if they do not actually pass into1 at least shade towards1 one another4 ,dana speaks of 8the endless diversities in individuals0 that compose a species1 and then states that a living species1 like an inorganic one1 8is based on a specific amount or condition of concentered force defined in the act or law of creation40 ,species1 he says1 are permanent1 and hybrids 8cannot seriously trifle with the true units of nature1 and at the best1 can only make temporary variations40 8,we have therefore reason to believe from man's fertile intermixture1 that he is one in species3 and that all organic species are divine appointments which cannot be obliterated1 unless by annihilating the individuals representing the species40 ,through the activities of the ,french the world was prepared for the reception of evolution1 and now it was already in the minds of many advanced thinkers4 ,in #ahfj ,asa ,gray sent to the editor of the ,journal 7#bi1 #a7 an article by the ,english botanist1 ,joseph ,d4 ,hooker1 entitled 8,on the ,origination and ,distribution of ,species10 with these significant remarks3 8,the essay cannot fail to attract the immediate and profound attention of scientific men4444 ,it has for some time been manifest that a re-statement of the ,lamarckian hypothesis is at hand4 ,we have this1 in an improved and truly scientific form1 in the theories which1 recently propounded by ,mr4 ,darwin1 followed by ,mr4 ,wallace1 are here so ably and altogether independently maintained4 ,when these views are fully laid before them1 the naturalists of this country will be able to take part in the interesting discussion which they will not fail to call forth40 ,hooker took up a study of the flora of ,tasmania1 of which the above cited article is but a chapter1 with a view to trying out ,darwin's theory1 and he now accepts it4 ,he says1 8,species are derivative and mutable40 8,the limits of the majority of species are so undefinable that few naturalists are agreed upon them40 ,asa ,gray had received from ,darwin an advance copy of the book that was to revolutionize the thought of the world1 and at once wrote for the ,journal a ,review of ,darwin's ,theory on the ,origin of ,species by means of ,natural ,selection 7#bi1 #aec1 #ahfj74 ,this is a splendid1 critical but just1 scientific review of ,darwin's epoch-making book4 ,evidently views similar to those1 of the ,english scientist had long been in the mind of ,gray1 for he easily and quickly mastered the work4 ,he is easy on ,dana's ,thoughts on ,species1 which were idealistic and not in harmony with the naturalistic views of ,darwin4 ,on the other hand1 he contrasts ,darwin's views at length with those of the creationists as exemplified by ,louis ,agassiz1 and says 8,the widest divergence appears40 ,gray says in part3 8,the gist of ,mr4 ,darwin's work is to show that such varieties are gradually diverged into species and genera through natural selection2 that natural selection is the inevitable result of the struggle for existence which all living things are engaged in2 and that this struggle is an unavoidable consequence of several natural causes1 but mainly of the high rate at which all organic beings tend to increase4 ,darwin is confident that intermediate forms must have existed2 that in the olden times when the genera1 the families and the orders diverged from their parent stocks1 gradations existed as fine as those which now connect closely related species with varieties4 ,but they have passed and left no sign4 ,the geological record1 even if all displayed to view1 is a book from which not only many pages1 but even whole alternate chapters have been lost out1 or rather which were never printed from the autographs of nature4 ,the record was actually made in fossil lithography only at certain times and under certain conditions 7i4e41 at periods of slow subsidence and places of abundant sediment72 and of these records all but the last volume is out of print2 and of its pages only local glimpses have been obtained4 ,geologists1 except ,lyell1 will object to this1--some of them moderately1 others with vehemence4 ,mr4 ,darwin himself admits1 with a candor rarely displayed on such occasions1 that he should have expected more geological evidence of transition than he finds1 and that all the most eminent paleontologists maintain the immutability of species4 ,the general fact1 however1 that the fossil fauna of each period as a whole is nearly intermediate in character between the preceding and the succeeding faunas1 is much relied on4 ,we are brought one step nearer to the desired inference by the similar #8fact1' insisted on by all paleontologists1 that fossils from two consecutive formations are far more closely related to each other1 than are the fossils of two remote formations4 ,it is well said that all organic beings have been formed on two great laws2 ,unity of type1 and ,adaptation to the conditions of existence4444 ,mr4 ,darwin harmonizes and explains them naturally4 ,adaptation to the conditions of existence is the result of ,natural ,selection2 ,unity of type1 of unity of descent40 ,gray's article was soon followed by another one from ,agassiz on ,individuality and ,specific ,differences among ,acalephs1 but the running title is 8,prof4 ,agassiz on the ,origin of ,species0 7#cj1 #adb1 #ahfj74 ,agassiz stoutly maintains his well known views1 and concludes as follows3 8,were the transmutation theory true1 the geological record should exhibit an uninterrupted succession of types blending gradually into one another4 ,the fact is that throughout all geological times each period is characterized by definite specific types1 belonging to definite genera1 and these to definite families1 referable to definite orders1 constituting definite classes and definite branches1 built upon definite plans4 ,until the facts of ,nature are shown to have been mistaken by those who have collected them1 and that they have a different meaning from that now generally assigned to them1 ,i shall therefore consider the transmutation theory as a scientific mistake1 untrue in its facts1 unscientific in its method1 and mischievous in its tendency40 ,dana1 in reviewing ,huxley's well known book1 ,man's ,place in ,nature 7#ce1 #dea1 #ahfc71 holds that man is apart from brute nature because man exhibits 8extreme cephalization0 in that he has arms that no longer are used in locomotion but go rather with the head1 and because he has a far higher mentality and speech4 ,as for the ,darwinian theory1 the evidence1 he says1 8comes from lower departments of life1 and is acknowledged by its advocates to be exceedingly scanty and imperfect40 ,the growth of evolution is set forth in the ,journal in ,asa ,gray's article on ,charles ,darwin 7#bd1 #dec1 #ahhb71 which speaks of the latter as 8the most celebrated man of science of the nineteenth century10 and1 in addition1 as 8one of the most kindly and charming1 unaffected1 simple-hearted1 and lovable of men40 ,in regard to the rise of evolution in ,america1 more can be had from ,dana's paper on ,asa ,gray 7#ce1 #aha1 #ahhh74 ,here we read1 as a sequel to his ,thoughts on ,species1 that the 8paper may be taken1 perhaps1 as a culmination of the past1 just as the new future was to make its appearance40 ,finally1 in this connection there should be mentioned ,o4 ,c4 ,marsh's paper on ,thomas ,henry ,huxley 7#ej1 #agg1 #ahie71 wherein is recorded the latter's share in the upbuilding of the evolutionary theory4 ,we have seen that originally ,dana was a creationist1 but in the course of his long and fruitful life he gradually became an evolutionist1 and rather a ,neo-,lamarckian than a ,darwinian4 ,this change may be traced in the various editions of his ,manual of ,geology1 and in the last edition of #ahie he says his 8speculative conclusions0 of #aheb in regard to the origin of species are not in 8accord with the author's present judgment40 8,the evidence in favor of evolution by variation is now regarded as essentially complete40 ,on the other hand1 while man is 8unquestionably0 closely related in structure to the man-apes1 yet he is not linked to them but stands apart1 through 8the intervention of a ,power above ,nature4444 ,believing that ,nature exists through the will and ever-acting power of the ,divine ,being1 and 444 that the whole ,universe is not merely dependent on1 but actually is1 the ,will of one ,supreme ,intelligence1 ,nature1 with ,man as its culminant species1 is no longer a mystery40 ,in ,america most of the paleontologists are ,neo-,lamarckian1 a school that was developed independently by ,e4 ,d4 ,cope 7#ahdj-ahig7 through the vertebrate evidence1 and by ,alpheus ,hyatt 7#ahch-aijb7 mainly on the evidence of the ammonites4 ,they hold that variations and acquired characters arise through the effects of the environment1 the mechanics of the organism resulting from the use and disuse of organs1 etc4 ,one of the leading exponents of this school is ,a4 ,s4 ,packard1 whose book on ,lamarck1 ,his ,life and ,work1 #aija1 fully explains the doctrines of the ,neo-,lamarckians4 ,the ,growth of ,invertebrate ,paleontology4 ,how and by whom paleontology has been developed has been fully stated in the ,journal in a very clear manner by ,professor ,marsh in his memorable presidential address of #ahgi1 ,history and ,methods of ,palontological ,discovery 7#ah1 #cbc1 #ahgi71 and by ,karl von ,zittel in his most interesting book1 ,history of ,geology and ,palontology1 #aija4 ,in this discussion we shall largely follow ,marsh4 ,the science of paleontology has passed through four periods1 the first of them the long ,mystic period extending up to the beginning of the seventeenth century1 when the idea that fossils were once living things was only rarely perceived4 ,the second period was the ,diluvial period of the eighteenth century1 when nearly everyone regarded the fossils as remains of the ,noachian deluge4 ,with the beginnings of the nineteenth century there arose in western ,europe the knowledge that fossils are the 8medals of creation0 and that they have a chronogenetic significance2 also that life had been periodically destroyed through world-wide convulsions in nature4 ,from about #ahjj to #ahfj was the time of the creationists and catastrophists1 which may be known as the ,catastrophic period4 ,the fourth period began in #ahfj with ,darwin's ,origin of ,species4 ,since that time the theory of evolution has pervaded all work in paleontology1 and accordingly this time may be known as the ,evolutionary period4 ,mystic ,period4--,the ,mystic period in paleontology begins with the ,greeks1 five centuries before the present era1 and continues down to the beginning of the seventeenth century of our time4 ,some correctly saw that the fossils were once living marine animals1 and that the sea had been where they now occur4 ,others interpreted fossil mammal bones as those of human giants1 the ,titans1 but the ,aristotelian view that they were of spontaneous generation through the hidden forces of the earth dominated all thought for about twenty centuries4 ,in the sixteenth century canals were being dug in ,northern ,italy1 and the many fossils so revealed led to a fierce discussion as to their actual nature4 ,leonardo da ,vinci 7#adeb-aeai7 opposed the commonly accepted view of their spontaneous generation and said that they were the remains of once living animals and that the sea had been where they occur4 8,you tell me10 he said1 8that ,nature and the influence of the stars have formed these shells in the mountains2 then show me a place in the mountains where the stars at the present day make shelly forms of different ages1 and of different species in the same place40 ,however1 nothing came of his teachings and those of his countryman ,fracastorio 7#adhc-aeec71 who further ridiculed the idea that they were the remains of the deluge4 ,the first mineralogist1 ,agricola1 described them as minerals--fossilia--and said that they arose in the ground from fatty matter set in fermentation by heat4 ,others said that they were freaks of nature4 ,martin ,lister 7#afch-agaa7 figured fossils side by side with living shells to show that they were extinct forms of life4 ,in the seventeenth century1 and especially in ,italy and ,germany1 many books were published on fossils1 some with illustrations so accurate that the species can be recognized to-day4 ,finally1 toward the close of this century the influence of ,aristotle and the scholastic tendency to disputation came more or less to an end4 ,fossils were already to many naturalists once living plants and animals4 ,marsh states3 8,the many collections of fossils that had been brought together1 and the illustrated works that had been published about them1 were a foundation for greater progress1 and1 with the eighteenth century1 the second period in the history of paleontology began40 ,diluvial ,period4--,during the eighteenth century many more books on fossils were published in western ,europe1 and now the prevalent explanation was that they were the remains of the ,noachian deluge4 ,for nearly a century theologians and laymen alike took this view1 and some of the books have become famous on this account1 but the diluvial views sensibly declined with the close of the eighteenth century4 ,the true nature of fossils had now been clearly determined4 ,they were the remains of plants and animals1 deposited long before the deluge1 part in fresh water and part in the sea4 8,some indicated a mild climate1 and some the tropics4 ,that any of these were extinct species1 was as yet only suspected40 ,yet before the close of the century there were men in ,england and ,france who pointed out that different formations had different fossils and that some of them were extinct4 ,these views then led to many fantastic theories as to how the earth was formed--dreams1 most of them have been called4 ,marsh says3 8,the dominant idea of the first sixteen centuries of the present era was1 that the universe was made for ,man4 ,this was the great obstacle to the correct determination of the position of the earth in the universe1 and1 later1 of the age of the earth4444 ,in a superstitious age1 when every natural event is referred to a supernatural cause1 science cannot live4444 ,scarcely less fatal to the growth of science is the age of ,authority1 as the past proves too well4 ,with freedom of thought1 came definite knowledge1 and certain progress2--but two thousand years was long to wait40 ,one of the most significant publications of this period was ,linnus's ,systema ,natur1 which appeared in #agce4 ,in this work was introduced binomial nomenclature1 or the system of giving each plant and animal species a generic and specific name1 as ,felis leo for the lion4 ,the system was1 however1 not established until the tenth edition of the work in #ageh1 which became the starting point of zoological nomenclature4 ,since then there has been added another canon1 the law of priority1 which holds that the first name applied to a given form shall stand against all later names given to the same organism4 ,catastrophic ,period4--,with the beginning of the nineteenth century there started a new era in paleontology1 and this was the time when the foundations of the science were laid4 ,the period continued for six decades1 or until the time of the ,origin of ,species4 ,marsh says that now 8method replaced disorder1 and systematic study superseded casual observation40 ,fossils were accurately determined1 comparisons were made with living forms1 and the species named according to the binomial system4 ,however1 every species1 recent and extinct1 was regarded as a separate creation1 and because of the usually sharp separation of the superposed fossil faunas and floras1 these were held to have been destroyed through a series of periodic catastrophes of which the ,noachian deluge was the last4 ,lamarck between #ahjb and #ahjf described the ,tertiary shells of the ,paris basin4 ,comparing them with the living forms1 he saw that most of the fossils were of extinct species1 and in this way he came to be the founder of modern invertebrate paleontology4 ,he also maintained after #ahja that life has been continuous since its origin and that nature has been uniform in the course of its development4 ,marsh adds3 8,his researches on the invertebrate fossils of the ,paris ,basin1 although less striking1 were not less important than those of ,cuvier on the vertebrates2 while the conclusions he derived from them form the basis of modern biology40 8,lamarck was the prophetic genius1 half a century in advance of his time40 ,cuvier established comparative anatomy and vertebrate paleontology1 and was one of the first to point out that fossil animals are nearly all extinct forms4 ,he came to the latter conclusion in #agif through a study of fossil elephants found in ,europe4 8,cuvier enriched the animal kingdom by the introduction of fossil forms among the living1 bringing all together into one comprehensive system40 ,this opened to him entirely new views respecting the theory of the earth1 and he devoted more than twenty-five years to developing the theories of special creation and catastrophism1 described in his ,discourse on the ,revolutions of the ,surface of the ,globe4 8,with all his knowledge of the earth1 he could not free himself from tradition1 and believed in the universality and power of the ,mosaic deluge4 ,again1 he refused to admit the evidence brought forward by his distinguished colleagues against the permanence of species1 and used all his great influence to crush out the doctrine of evolution1 then first proposed0 7,marsh74 ,in ,england it was ,william ,smith 7#agfi-ahci7 who independently discovered the chronogenetic significance of fossils1 and in their stratigraphic superposition indicated the way for the study of historical geology4 ,he first published on this matter in #agii1 but his completed statements came in works entitled 8,strata identified by ,organized ,fossils10 #ahaf-ahbj1 and 8,stratigraphical ,system of ,organized ,fossils10 #ahag4 ,invertebrate paleontology in ,america during the ,catastrophic period had its beginning in ,lesueur1 who in #ahah described the ,ordovician gastropod ,maclurites magna4 ,all of the paleontologists of this time were satisfied to describe species and genera and to ascertain in a broad way the stratigraphic significance of the fossil faunas and floras4 ,james ,hall in #ahed 7#ag1 #cab7 knew of #aehh species1 described and undescribed1 in the ,new ,york system1 while in ,england ,morris listed in that year #hcjj ,paleozoic forms4 ,in #ahef ,dana recites the known fossil species as follows 7#bb1 #ccc73 ,the whole number of known ,american species of animals of the ,permian to ,recent is about #bjjj2 while in ,britain and ,europe1 there were over #bj1jjj species4 ,in the ,permian we have none1 while ,europe has over #bjj species4 ,in the ,triassic we have none1 ,europe #ajjj species2 ,jurassic #fj1 ,europe over #djjj2 ,cretaceous #cej to #djj1 ,europe about #fjjj2 ,tertiary hardly #aejj1 ,europe about #hjjj4 ,since that time nearly all of the larger ,american ,paleozoic faunas have been developed1 but there are thousands of species yet to be described4 ,who the more prominent ,american paleontologists of this period were has been told in the section on the development of the geological column4 ,the grander paleontologic results of the ,catastrophic period have been so well stated by ,marsh that it is worth our while to repeat them here3 8,it had now been proved beyond question that portions at least of the earth's surface had been covered many times by the sea1 with alternations of fresh water and of land2 that the strata thus deposited were formed in succession1 the lowest of the series being the oldest2 that a distinct succession of animals and plants had inhabited the earth during the different geological periods2 and that the order of succession found in one part of the earth was essentially the same in all4 ,more than #cj1jjj new species of extinct animals and plants had now been described4 ,it had been found1 too1 that from the oldest formations to the most recent1 there had been an advance in the grade of life1 both animal and vegetable1 the oldest forms being among the simplest1 and the higher forms successively making their appearance4 ,it had now become clearly evident1 moreover1 that the fossils from the older formations were all extinct species1 and that only in the most recent deposits were there remains of forms still living4444 ,another important conclusion reached1 mainly through the labors of ,lyell1 was1 that the earth had not been subjected in the past to sudden and violent revolutions2 but the great changes wrought had been gradual1 differing in no essential respect from those still in progress4 ,strangely enough1 the corollary to this proposition1 that life1 too1 had been continuous on the earth1 formed at that date no part of the common stock of knowledge4 ,in the physical world1 the great law of #8correlation of forces' had been announced1 and widely accepted2 but in the organic world1 the dogma of the miraculous creation of each separate species still held sway40 ,evolutionary ,period4--,this period begins with #ahfj and the publication of ,darwin's ,origin of ,species 7late in #ahei74 ,it is the period of modern paleontology1 and is dominated by the belief that universal laws pervade not only inorganic matter1 but all life as well4 ,louis ,agassiz had been in ,america fourteen years when ,darwin's book appeared1 and his wonderful influence in bringing the zoology of our country to a high stand and the further influence he exerted through his students was bound to react beneficially on invertebrate paleontology4 ,shortly after the beginning of this period1 or in #ahfg1 ,alpheus ,hyatt1 one of ,agassiz's students1 began to apply the study of embryology to fossil cephalopods1 showing clearly that these shells retain a great deal of their growth stages or ontogeny4 ,this method of study was then followed by ,r4 ,t4 ,jackson1 ,c4 ,e4 ,beecher1 and ,j4 ,p4 ,smith1 and has been productive of natural classifications of the ,cephalopoda1 ,brachiopoda1 ,trilobita1 and ,echinoidea4 ,the dominant invertebrate paleontologist of this period was of course ,james ,hall1 who described about #ejjj species of ,american ,paleozoic fossils4 ,he also built up the ,new ,york ,state ,museum1 while around his private collections of fossils have been developed the ,american ,museum of ,natural ,history in ,new ,york ,city and the ,walker ,museum at the ,university of ,chicago4 ,in his most important laboratory of paleontology at ,albany1 there have been trained either wholly or in part the following paleontologists3 ,f4 ,b4 ,meek1 ,c4 ,a4 ,white1 ,r4 ,p4 ,whitfield1 ,c4 ,d4 ,walcott1 ,c4 ,e4 ,beecher1 ,john ,m4 ,clarke1 and ,charles ,schuchert4 ,in ,canada1 through the work of the ,geological ,survey of the ,dominion1 came the paleontologists ,elkanah ,billings and1 later on1 ,j4 ,f4 ,whiteaves4 ,the 8father of ,canadian paleontology10 ,sir ,william ,dawson1 who developed independently1 was active in all branches of the science and did much to unravel the geology of eastern ,canada4 ,no organism has been more discussed and more often rejected and accepted as a fossil than his 8dawn animal of ,canada10 ,eozoon canadense1 first described in #ahfe4 ,his son1 ,george ,m4 ,dawson1 was one of the directors of the ,geological ,survey of ,canada4 ,finally the extensive paleontology of the ,cambrian of ,canada was worked out by another self-made paleontologist1 ,g4 ,f4 ,matthew4 ,paleobotany4--,american paleobotany was developed during this1 the fourth period1 through the state and national surveys1 first in ,leo ,lesquereux1 a ,swiss student induced by ,agassiz to come to ,america1 and in ,j4 ,s4 ,newberry4 ,the second generation of paleobotanists is represented by ,lester ,f4 ,ward and ,w4 ,n4 ,fontaine1 and the third generation1 the present workers1 includes ,f4 ,h4 ,knowlton1 ,david ,white1 ,arthur ,hollick1 and ,e4 ,w4 ,berry4 ,a new line of paleobotanical work1 the histology of woody but pseudomorphous remains1 has been developed by ,g4 ,r4 ,wieland4 ,the grander results of the study of paleontology during the evolutionary period may be summed up with the conclusions of ,marsh3 8,one of the main characteristics of this epoch is the belief that all life1 living and extinct1 has been evolved from simple forms4 ,another prominent feature is the accepted fact of the great antiquity of the human race4 ,these are quite sufficient to distinguish this period sharply from those that preceded it40 ,charles ,darwin's work at once aroused attention1 and brought about in scientific thought a revolution which 8has influenced paleontology as extensively as any other department of science4444 ,in the previous period species were represented independently by parallel lines2 in the present period1 they are indicated by dependent1 branching lines4 ,the former was the analytic1 the latter is the synthetic period40 ,synthetic ,period4--,what is to be the next trend in paleontology8 ,clearly it is to be the ,synthetic period1 one that ,marsh in #ahgi indicated in these words3 8,but if we are permitted to continue in imagination the rapidly converging lines of research pursued to-day1 they seem to meet at the point where organic and inorganic nature become one4 ,that this point will yet be reached1 ,i cannot doubt40 ,this ,synthetic period1 foreshadowed also in ,herbert ,spencer's ,synthetic ,philosophy1 has not yet arrived1 but before long another great leader will appear4 ,we have the prophecy of his coming in such books as ,the ,fitness of the ,environment1 by ,lawrence ,j4 ,henderson1 #aiac2 ,the ,origin and ,nature of ,life1 by ,benjamin ,moore1 #aiac2 ,the ,organism as a ,whole1 by ,jacques ,loeb1 #aiaf2 and ,the ,origin and ,evolution of ,life1 by ,henry ,f4 ,osborn1 #aiag4 ,in all nature1 inorganic and organic1 there is continuity and consistency1 beauty and design4 ,we are beginning to see that there are eternal laws1 ever interacting and resulting in progressive and regressive evolutions4 ,the realization of these scientific revelations kindles in us a desire for more knowledge1 and the grandest revelations are yet before us in the synthesis of the sciences4 ,notes4 ,footnote #c3 ,for more detail in regard to these tillites and the older ones see ,climates of ,geologic ,time1 by ,charles ,schuchert1 being ,chapter ,,xxi in ,huntington's ,climatic ,factor as ,illustrated in ,arid ,america1 ,publication ,no4 #aib of the ,carnegie ,institution of ,washington1 #aiad4 ,also ,arthur ,p4 ,coleman's presidential address before the ,geological ,society of ,america in #aiae1 ,dry ,land in ,geology1 published in the ,society's ,bulletin1 #bg1 #age1 #aiaf4 ,,iii ,a ,,century ,,of ,,geology4--,,steps ,,of ,,progress ,,in ,,the ,,interpretation ,,of ,,land ,,forms ,by ,,herbert ,e4 ,,gregory ,the essence of physiography is the belief that land forms represent merely a stage in the orderly development of the earth's surface features2 that the various dynamic agents perform their characteristic work throughout all geologic time4 ,the formulation of principle and processes of earth sculpture was1 therefore1 impossible on the hypothesis of a ready-made earth whose features were substantially unchangeable1 except when modified by catastrophic processes4 ,in #ahba1 ,j4 ,w4 ,wilson wrote in the ,journal3 8,is it not the best theory of the earth1 that the ,creator1 in the beginning1 at least at the general deluge1 formed it with all its present grand characteristic features80#d ,if so1 a search for causes is futile1 and the study of the work performed by streams and glaciers and wind is unprofitable4 ,the belief in the ,deluge as the one great geological event in the history of the earth has brought it about that the speculations of ,aristotle1 ,herodotus1 ,strabo1 and ,ovid1 and the illustrious ,arab1 ,avicenna 7#ihj-ajcg71 unchecked by appeal to facts but also unopposed by priesthood or popular prejudice1 are nearer to the truth than the intolerant controversial writings of the intellectual leaders whose touchstone was orthodoxy4 ,a few thinkers of the sixteenth century revolted against the interminable repetition of error1 and ,peter ,severinus 7#aega7 advised his students3 8,burn up your books 444 buy yourselves stout shoes1 get away to the mountains1 search the valleys1 the deserts1 the shores of the seas4444 ,in this way and no other will you arrive at a knowledge of things40 ,but the thoroughgoing 8diluvialist0 who believed that a million species of animals could occupy a #dej-;foot ,ark1 but not that pebbles weathered from rock or that rivers erode1 had no use for his powers of observation4 ,sporadic germs of a science of land forms scattered through the literature of the seventeenth and eighteenth centuries found an unfavorable environment and produced inconspicuous growths4 ,even their sponsors did little to cultivate them4 ,steno 7#afca-afhg7 mildly suggested that surface sculpturing1 particularly on a small scale1 is largely the work of running water1 and ,guettard 7#agae-aghf71 a truly great mind1 grasped the fundamental principles of denudation and successfully entombed his views as well as his reputation in scores of books and volumes of cumbrous diffuse writing4 ,at the beginning of the nineteenth century a sufficient body of principles had been established to justify the recognition of an earth science1 geology1 and the #aie volumes of the ,journal thus far published carry a large part of the material which has won approval for the new science and given prominence to ,american thought4 ,from the pages in the ,journal1 the progress of geology may be illustrated by tracing the fluctuation in the development of fact and theory as relates to valleys and glacial features1 the subjects to which this chapter is devoted4 ,the ,interpretation of ,valleys4 ,the ,pioneers4 ,desmarest 7#agbe-ahae7 might be styled the father of physiography4 ,by concrete examples and sound induction he established 7#aggd7 the doctrine that the valleys of central ,france are formed by the streams which occupy them4 ,he also made the first attempt to trace the history of a landscape through its successive stages on the basis of known causes4 ,his methods and reasoning are practically identical with those of ,dutton working in the ancient lavas of ,new ,mexico2 and ,whitney's description of the ,table ,mountains of ,california might well have appeared in ,desmarest's memoirs4#e ,the teachings of ,desmarest were strengthened and expanded by ,de,saussure 7#agdj-agii71 the sponsor for the term1 8,geology10 7#aggi7 who saw in the intimate relation of ,alpine streams and valleys the evidence of erosion by running water 7#aghf74 ,the work of these acknowledged leaders of geological thought attracted singularly little attention on the ,continent1 and ,lamarck's volume on denudation 7,hydrogologie71 which appeared in #ahjb1 although an important contribution1 sank out of sight4 ,but the seed of the ,french school found fertile ground in ,edinburgh1 the center of the geological world during the first quarter of the nineteenth century4 ,hutton's 8,theory of the ,earth1 with ,proofs and ,illustrations10 in which the guidance of ,de,saussure and ,desmarest is gratefully acknowledged1 appeared in #agie4 ,the original publication aroused only local interest1 but when placed in attractive form by ,playfair's 8,illustrations of the ,huttonian ,theory0 7#ahjb71 the problem of the origin and development of land forms assumed a commanding position in geological thought4 ,hutton was peculiarly fortunate in his environment4 ,he had the support and assistance of a group of able scientific colleagues as well as the bitter opposition of ,jameson and of the defenders of orthodoxy4 ,his views were discussed in scientific publications and found their way to literary and theological journals4 ,hutton's conception of the processes of land sculpture--slow upheaving and slow degradation of mountains1 differential weathering1 and the carving of valleys by streams--has a very modern aspect4 ,playfair's book would scarcely be out of place in a twentieth century class room4 ,the following paragraphs are quoted from it3#f 8444 ,a river1 of which the course is both serpentine and deeply excavated in the rock1 is among the phenomena1 by which the slow waste of the land1 and also the cause of that waste1 are most directly pointed out4 ,the structure of the vallies among mountains1 shews clearly to what cause their existence is to be ascribed4 ,here we have first a large valley1 communicating directly with the plain1 and winding between high ridges of mountains1 while the river in the bottom of it descends over a surface1 remarkable1 in such a scene1 for its uniform declivity4 ,into this1 open a multitude of transverse or secondary vallies1 intersecting the ridges on either side of the former1 each bringing a contribution to the main stream1 proportioned to its magnitude2 and1 except where a cataract now and then intervenes1 all having that nice adjustment in their levels1 which is the more wonderful1 the greater the irregularity of the surface4 ,these secondary vallies have others of a smaller size opening into them2 and1 among mountains of the first order1 where all is laid out on the greatest scale1 these ramifications are continued to a fourth1 and even a fifth1 each diminishing in size as it increases in elevation1 and as its supply of water is less4 ,through them all1 this law is in general observed1 that where a higher valley joins a lower one1 of the two angles which it makes with the latter1 that which is obtuse is always on the descending side2 444 what else but the water itself1 working its way through obstacles of unequal resistance1 could have opened or kept up a communication between the inequalities of an irregular and alpine surface4444 444 ,the probability of such a constitution arrangement of valleys having arisen from another cause1 is1 to the probability of its having arisen from the running of water1 in such a proportion as unity bears to a number infinitely great4 444 ,with ,dr4 ,hutton1 we shall be disposed to consider those great chains of mountains1 which traverse the surface of the globe1 as cut out of masses vastly greater1 and more lofty than any thing that now remains4 ,from this gradual change of lakes into rivers1 it follows1 that a lake is but a temporary and accidental condition of a river1 which is every day approaching to its termination2 and the truth of this is attested1 not only by the lakes that have existed1 but also by those that continue to exist40 ,steps ,backward4 ,even ,hutton's clear reasoning1 firmly buttressed by concrete examples1 was insufficient to overcome the belief in ready-made or violently formed valleys and original corrugations and irregularities of mountain surface4 ,the pages of the ,journal show that the principles laid down by ,playfair were too far in advance of the times to secure general acceptance4 ,in the first volume of the ,journal1 the gorge of the ,french ,broad ,river is assigned by ,kain to 8some dreadful commotion in nature which probably shook these mountains to their bases10#g and the gorge of the lower ,connecticut is considered by ,hitchcock 7#ahbd7h as a breach which drained a series of lakes 8not many centuries before the settlement of this country40 ,the prevailing ,american and ,english view for the first quarter of the nineteenth century is expressed in the reviews in this ,journal1 where the well-known conclusions of ,conybeare and ,phillips that streams are incompetent to excavate valleys are quoted with approval and admiration is expressed for ,buckland's famous 8,reliqui ,diluvian10 a #cjj-page quarto volume devoted to proof of a deluge4 ,the professor at ,yale1 ,silliman1 and the professor at ,oxford1 ,buckland1 saw that an acceptance of ,hutton's views involved a repudiation of the ,biblical flood1 and much space is devoted to combating these 8erroneous0 and 8unscientific0 views4 ,for example1 ,buckland says3#i 8444 ,the general belief is1 that existing streams1 avalanches and lakes1 bursting their barriers1 are sufficient to account for all their phenomena1 and not a few geologists1 especially those of the ,huttonian school1 at whose head is ,professor ,playfair1 have till recently been of this opinion4444 ,but it is now very clear to almost every man1 who impartially examines the facts in regard to existing vallies1 that the causes now in action1 mentioned above1 are altogether inadequate to their production2 nay1 that such a supposition would involve a physical impossibility4 ,we do not believe that one-thousandth part of our present vallies were excavated by the power of existing streams4444 ,in very many cases of large rivers1 it is found1 that so far from having formed their own beds1 they are actually in a gradual manner filling them up4 ,again2 how happens it that the source of a river is frequently below the head of a valley1 if the river excavated that valley8 ,the most powerful argument1 however1 in our opinion1 against the supposition we are combating1 is the phenomena of transverse and longitudinal valleys2 both of which could not possibly have been formed by existing streams40 ,phillips writes in #ahbi3aj 8,the excavation of valleys can be ascribed to no other cause than a great flood of water which overtopped the hills1 whose summits those vallies descend40 ,faith in ,noah's flood as the dominant agent of erosion rapidly lost ground through the teaching of ,lyell after #ahcj1 but the theory of systematic development of landscapes by rivers gained little4 ,in fact1 ,scrope in #ahcj1aa in showing that the entrenched meanders of the ,moselle prove gradual progressive stream work1 was in advance of his ,english contemporary4 ,judged by contributions to the ,journal1 ,lyell's teaching served to standardize ,american opinion of earth sculpture somewhat as follows3 ,the ocean is the great valley maker1 but rivers also make them2 the position of valleys is determined by original or renewed surface inequalities or by faulting2 exceptional occurrences--earthquakes1 bursting of lakes1 upheavals and depressions--have played an important part4 ,hayes 7#ahci7ab thought that the surface of ,new ,york was essentially an upraised sea-bottom modified by erosion of waves and ocean currents4 ,sedgwick 7#ahch7ac considered high-lying lake basins proof of valleys which were shaped under the sea4 ,many of the valleys in the ,chilian ,cordillera were thought by ,darwin 7#ahdd7 to have been the work of waves and tides1 and water gaps are ascribed to currents 8bursting through the range at those points where the strata have been least inclined and the height consequently is less40 ,speaking of the magnificent stream-cut canyons of the ,blue ,mountains of ,new ,south ,wales1 gorges which lead to narrow exits through monoclines1 ,darwin says3 8,to attribute these hollows to alluvial action would be preposterous40#ad ,the influence of structure in the formation of valleys is emphasized by many contributors to the ,journal4 ,hildreth in #ahcf1 in a valuable paper1#ae which is perhaps the first detailed topographic description of drainage in folded strata1 expresses the opinion that the ,west ,virginia ridges and valleys antedated the streams and that water gaps though cut by rivers involve pre-existing lakes4 ,geddes 7#ahbf7af denied that ,niagara ,river cut its channel and speaks of valleys which 8were valleys e'er moving spirit bade the waters flow40 ,conrad 7#ahci7ag discussed the structural control of the ,mohawk1 the ,ohio1 and the ,mississippi1 and ,lieutenant ,warren 7#ahei7ah concluded that the ,niobrara must have originated in a fissure4 ,according to ,lesley 7#ahfb7ai the course of the ,new ,river across the ,great ,valley and into the ,appalachians 8striking the escarpment in the face0 is determined by the junction of anticlinal structures on the north with faulted monoclines toward the south2 a conclusion in harmony with the views of ,edward ,hitchcock 7#ahda7ag that major valleys and mountain passes are structural in origin and that even subordinate folds and faults may determine minor features4 8,is not this a beautiful example of prospective benevolence on the part of the ,deity1 thus1 by means of a violent fracture of primary mountains1 to provide for easy intercommunication through alpine regions1 countless ages afterwards60 ,the extent of the wandering from the guidance of ,de,saussure and ,playfair after the lapse of #ej years is shown by students of ,switzerland4 ,alpine valleys to ,murchison 7#ahea7 were bays of an ancient sea2 ,schlaginweit 7#aheb7 found regional and local complicated crustal movements a satisfactory cause1 and ,forbes 7#ahfc7 saw only glaciers4 ,valleys ,formed by ,rivers4 ,one strong voice before #ahfj appears to have called ,americans back to truths expounded by ,desmarest and ,hutton4 ,dana in #ahejbj amply demonstrated that valleys on the ,pacific ,islands owe neither their origin1 position or form to the sea or to structural factors4 ,they are the work of existing streams which have eaten their way headwards4 ,even the valleys of ,australia cited by ,darwin as type examples of ocean work are shown to be products of normal stream work4 ,dana went further and gave a permanent place to the ,huttonian idea that many bays1 inlets1 and fiords are but the drowned mouths of stream-made valleys4 ,in the same volume in which these conclusions appeared1 ,hubbard 7#ahej7ba announced that in ,new ,hampshire the 8deepest valleys are but valleys of erosion40 ,the theory that valleys are excavated by streams which occupy them was all but universally accepted after ,f4 ,v4 ,hayden's description#bb of ,rocky ,mountain gorges 7#ahfb7 and ,newberry's interpretation of the canyons of ,arizona 7#ahfb72 but the scientific world was poorly prepared for ,newberry's statement3#bc 8,like the great canons of the ,colorado1 the broad valleys bounded by high and perpendicular walls belong to a vast system of erosion1 and are wholly due to the action of water4444 ,the first and most plausible explanation of the striking surface features of this region will be to refer them to that embodiment of resistless power--the sword that cuts so many geological knots--volcanic force4 ,the ,great ,canon of the ,colorado would be considered a vast fissure or rent in the earth's crust1 and the abrupt termination of the steps of the table lands as marking lines of displacement4 ,this theory though so plausible1 and so entirely adequate to explain all the striking phenomena1 lacks a single requisite to acceptance1 and that is truth40 ,with such stupendous examples in mind1 the dictum of ,hutton seemed reasonable3 8there is no spot on which rivers may not formerly have run40 ,denudation by ,rivers4 ,the general recognition of the competency of streams to form valleys was a necessary prelude to the broader view expressed by ,jukes 7#ahfb7bd 8,the surfaces of our present lands are as much carved and sculptured surfaces as the medallion carved from the slab1 or the statue sculptured from the block4 ,they have been gradually reached by the removal of the rock that once covered them1 and are themselves but of transient duration1 always slowly wasting from decay40 ,contributions to the ,journal between #ahej and #ahgj reveal a tendency to accept greater degrees of erosion by rivers1 but the necessary end-product of subarial erosion--a plain--is first clearly defined by ,powell in #ahge4be ,in formulating his ideas ,powell introduced the term 8base-level10 which may be called the germ word out of which has grown the 8cycle of erosion10 the master key of modern physiographers4 ,the original definition of base-level follows3 8,we may consider the level of the sea to be a grand base-level1 below which the dry lands cannot be eroded2 but we may also have1 for local and temporary purposes1 other base-levels of erosion1 which are the levels of the beds of the principal streams which carry away the products of erosion4 7,i take some liberty in using the term #8level' in this connection1 as the action of a running stream in wearing its channel ceases1 for all practical purposes1 before its bed has quite reached the level of the lower end of the stream4 ,what ,i have called the base-level would1 in fact1 be an imaginary surface1 inclining slightly in all its parts toward the lower end of the principal stream draining the area through which the level is supposed to extend1 or having the inclination of its parts varied in direction as determined by tributary streams470 ,analysis of ,powell's view has given definiteness to the distinction between 8base-level10 an imaginary plane1 and 8a nearly featureless plain10 the actual land surface produced in the last stage of subarial erosion4 ,following their discovery in the ,colorado ,plateau ,province1 denudation surfaces were recognized on the ,atlantic slope and discussed by ,mc,gee 7#ahhh71bf in a paper notable for the demonstration of the use of physiographic methods and criteria in the solution of stratigraphic problems4 ,davis 7#ahhi7bg described the upland of southern ,new ,england developed during ,cretaceous time1 introducing the term 8peneplain10 8a nearly featureless plain40 ,the short-lived opposition to the theory of peneplanation indicates that in ,america at least the idea needed only formulation to insure acceptance4 ,it is interesting to note that surfaces now classed as peneplains were fully described by ,percival 7#ahdb71bh who assigned them to structure1 and by ,kerr 7#ahhj71bi who considered glaciers the agent4 ,in ,europe 8plains of denudation0 have been clearly recognized by ,ramsay 7#ahdf71 ,jukes 7#ahfb71 ,a4 ,geikie 7#ahfe71 ,foster and ,topley 7#ahfe71 ,maw 7#ahff71 ,wynne 7#ahfg71 ,whitaker 7#ahfg71 ,macintosh 7#ahfi71 ,green 7#ahhb71 ,richthofen 7#ahhb71 but all of them were looked upon as products of marine work1 and writers of more recent date in ,england seem reluctant to give a subordinate place to the erosive power of waves4 ,americans1 on the other hand1 have been thinking in terms of rivers1 and the great contribution of the ,american school is not that peneplains exist1 but that they are the result of normal subarial erosion4 ,more precise field methods during the past decade have revealed the fact that no one agent is responsible for the land forms classed as peneplains2 that not only rivers and ocean1 but ice1 wind1 structure1 and topographic position must be taken into account4 ,the recognition of rivers as valley-makers and of the final result of stream work necessarily preceded an analysis of the process of subarial erosion4 ,the first and last terms were known1 the intermediate terms and the sequence remained to be established4 ,a significant contribution to this problem was made by ,jukes 7#ahfb74cd 8444 ,i believe that the lateral valleys are those which were first formed by the drainage running directly from the crests of the chains1 the longitudinal ones being subsequently elaborated along the strike of the softer or more erodable beds exposed on the flanks of those chains40 ,powell's discussion of antecedent and consequent drainage 7#ahge7 and ,gilbert's chapter on land sculpture in the ,henry ,mountain report 7#ahhj7 are classics1 and ,mc,gee's contribution#cj contains significant suggestions1 but the master papers are by ,davis1#ca who introduces an analysis of land forms based on structure and age by the statement3 8,being fully persuaded of the gradual and systematic evolution of topographical forms it is now desired 444 to seek the causes of the location of streams in their present courses2 to go back if possible to the early date when central ,pennsylvania was first raised from the sea1 and trace the development of the several river systems then implanted upon it from their ancient beginning to the present time40 ,that such a task could have been undertaken a quarter of a century ago and to-day considered a part of everyday field work shows how completely the lost ground of a half century has been regained and how rapid the advance in the knowledge of land sculpture since the canyons of the ,colorado ,plateau were interpreted4 ,features ,resulting from ,glaciation4 ,the ,problem ,stated4 ,early in the nineteenth century when speculation regarding the interior of the earth gave place in part to observations of the surface of the earth1 geologists were confronted with perhaps the most difficult problem in the history of the science4 ,as stated by the editor of the ,journal in #ahba3cb 8,the almost universal existence of rolled pebbles1 and boulders of rock1 not only on the margin of the oceans1 seas1 lakes1 and rivers2 but their existence1 often in enormous quantities1 in situations quite removed from large waters2 inland1--in high banks1 embedded in strata1 or scattered1 occasionally1 in profusion1 on the face of almost every region1 and sometimes on the tops and declivities of mountains1 as well as in the vallies between them2 their entire difference1 in many cases1 from the rocks in the country where they lie--rounded masses and pebbles of primitive rocks being deposited in secondary and alluvial regions1 and vice versa2 these and a multitude of similar facts have ever struck us as being among the most interesting of geological occurrences1 and as being very inadequately accounted for by existing theories40 ,the phenomena demanding explanation--jumbled masses of 8diluvium10 polished and striated rock1 bowlders distributed with apparent disregard of topography--were indeed startling4 ,even ,lyell1 the great exponent of uniformitarianism1 appears to have lost faith in his theories when confronted with facts for which known causes seemed inadequate4 ,the interest aroused is attested by #ca titles in the ,journal during its first two decades1 articles which include speculations unsupported by logic or fact1 field observation unaccompanied by explanation1 field observation with fantastic explanation1 ex-cathedra pronouncements by prominent men1 sound reasoning from insufficient data1 and unclouded recognition of cause and effect by both obscure and prominent men4 ,with little knowledge of glaciers1 areal geology1 or of structure and composition of drift1 all known forces were called in3 normal weathering1 catastrophic floods1 ocean currents1 waves1 icebergs1 glaciers1 wind1 and even depositions from a primordial atmosphere 7,chabier1 #ahbc74 ,human agencies were not discarded4 ,speaking of a granite bowlder at ,north ,salem1 ,new ,york1 described by ,cornelius 7#ahbj7cc as resting on limestone1 ,finch 7#ahbd7cd says3 8it is a magnificent cromlech and the most ancient and venerable monument which ,america possesses40 ,in the absence of a known cause1 catastrophic agencies seem reasonable4 ,the ,deluge4 ,in the seventh volume of the ,journal 7#ahbd7ce we read3 8,after the production of these regular strata of sand1 clay1 limestone1 c4 came a terrible irruption of water from the north1 or northwest1 which in many places covered the preceding formations with diluvial gravel1 and carried along with it those immense masses of granite1 and the older rocks1 which attest to the present day the destruction and ruin of a former world40 ,another author remarks3 8,we find a mantle as it were of sand and gravel indifferently covering all the solid strata1 and evidently derived from some convulsion which has lacerated and partly broken up those strata44440 ,the catastrophe favored by most geologists was floods of water violently released--8we believe10 says the editor1 8that all geologists agree in imputing 444 the diluvium to the agency of a deluge at one period or another40#cf ,such conclusions rested in no small way upon ,hayden's well-known treatise on surficial deposits 7#ahba71cg a volume which deserves a prominent place in ,american geological literature4 ,hayden clearly distinguished the topographic and structural features of the drift but found an adequate cause in general wide-spread currents which 8flowed impetuously across the whole continent 444 from north east to south west40 ,in reviewing ,hayden's book ,silliman remarks3 8,the general cause of these currents ,mr4 ,hayden concludes to be the deluge of ,noah4 ,while no one will object to the propriety of ascribing very many1 probably most of our alluvial features1 to that catastrophe1 we conceive that neither ,mr4 ,hayden1 nor any other man1 is bound to prove the immediate physical cause of that vindictive infliction4 ,we would beg leave to suggest the following as a cause which may have aided in deluging the earth1 and which1 were there occasion1 might do it again4 ,the existence of enormous caverns in the bowels of the earth1 7so often imagined by authors17 appears to be no very extravagant assumption4 ,it is true it cannot be proved1 but in a sphere of eight thousand miles in diameter1 it would appear in no way extraordinary1 that many cavities might exist1 which collectively1 or even singly1 might well contain much more than all our oceans1 seas1 and other superficial waters1 none of which are probably more than a few miles in depth4 ,if these cavities communicate in any manner with the oceans1 and are 7as if they exist at all1 they probably are17 filled with water1 there exist1 we conceive1 agents very competent to expel the water of these cavities1 and thus to deluge1 at any time1 the dry land40 ,the teachings of ,hayden were favorably received by ,hitchcock1 ,struder1 and ,hubbard1 and many ,europeans4 ,they found a champion in ,jackson1 who states 7#ahci73ch 8,from the observations made upon ,mount ,ktaadn1 it is proved1 that the current did rush over the summit of that lofty mountain1 and consequently the diluvial waters rose to the height of more than #e1jjj feet4 ,hence we are enabled to prove1 that the ancient ocean1 which rushed over the surface of the ,state1 was at least a mile in depth1 and its transporting power must have been greatly increased by its enormous pressure40 ,gibson1 a student of western geology1 reaches the same conclusion 7#ahcf73ci 8,that a wide-spread current1 although not1 as imagined1 fed from an inland sea1 once swept over the entire region between the ,alleghany and the ,rocky ,mountains is established by plenary proof40 ,professor ,sedgwick 7#ahca7 thought the sudden upheaval of mountains sufficient to have caused floods again and again4 ,the strength of the belief in the ,biblical flood1 during the first quarter of the #aith century1 may be represented by the following remarks of ,phillips 7#ahcb73dj 8,of many important facts which come under the consideration of geologists1 the #8,deluge' is1 perhaps1 the most remarkable2 and it is established by such clear and positive arguments1 that if any one point of natural history may be considered as proved1 the deluge must be admitted to have happened1 because it has left full evidence in plain and characteristic effects upon the surface of the earth40 ,however1 the theory of deluges1 whether of ocean or land streams1 did not hold the field unopposed4 ,in #ahbc1 ,granger1#da an observer whose contributions to science total only six pages1 speaks of the stri on the shore of ,lake ,erie as 8having been formed by the powerful and continued attrition of some hard body4444 ,to me1 it does not seem possible that water under any circumstances1 could have effected it4 ,the flutings in width1 depth1 and direction1 are as regular as if they had been cut out by a grooving plane4 ,this1 running water could not effect1 nor could its operation have produced that glassy smoothness1 which1 in many parts1 it still retains40 ,hayes and also ,conrad expressed similar views in the ,journal #af years later4 ,the idea that ice was in some way concerned with the transportation of drift has had a curious history4 ,the first unequivocal statement1 based on reading and keen observation1 was made in the ,journal by ,dobson in #ahbf3db 8,i have had occasion to dig up a great number of bowlders1 of red sandstone1 and of the conglomerate kind1 in erecting a cotton manufactory2 and it was not uncommon to find them worn smooth on the under side1 as if done by their having been dragged over rocks and gravelly earth1 in one steady position4 ,on examination1 they exhibit scratches and furrows on the abraded part2 and if among the minerals composing the rock1 there happened to be pebbles of feldspar1 or quartz1 7which was not uncommon17 they usually appeared not to be worn so much as the rest of the stone1 preserving their more tender parts in a ridge1 extending some inches4 ,when several of these pebbles happen to be in one block1 the preserved ridges were on the same side of the pebbles1 so that it is easy to determine which part of the stone moved forward1 in the act of wearing4 ,these bowlders are found1 not only on the surface1 but ,i have discovered them a number of feet deep1 in the earth1 in the hard compound of clay1 sand1 and gravel4444 ,i think we cannot account for these appearances1 unless we call in the aid of ice along with water1 and that they have been worn by being suspended and carried in ice1 over rocks and earth1 under water40 ,in ,dobson's day the hypothesis of 8gigantic floods10 8debacles10 8resistless world-wide currents10 was so firmly entrenched that the voice of the observant layman found no hearers1 and a letter from ,dobson to ,hitchcock written in #ahcg and containing additional evidence and argument remained unpublished until ,murchison1 in #ahdb1dc paid his respects to the remarkable work of a remarkable man4#dd 8,i take leave of the glacial theory in congratulating ,american science in having possessed the original author of the best glacial theory1 though his name had escaped notice2 and in recommending to you the terse argument of ,peter ,dobson1 a previous acquaintance with which might have saved volumes of disputation on both sides of the ,atlantic40 ,glaciers vs4 ,icebergs4 ,the glacial theory makes its way into geological literature with the development of ,agassiz 7#ahcg7 of the views of ,venetz 7#ahcc7 and ,charpentier 7#ahcd71 that the glaciers of the ,alps once had greater extent4 ,the bold assumption was made that the surface of ,europe as far south as the shores of the ,mediterranean and ,caspian seas was covered by ice during a period immediately preceding the present4 ,the kernel of the present glacial theory is readily recognizable in these early works1 but it is wrapped in a strange husk3 it was assumed that the ,alps were raised by a great convulsion under the ice and that the erratics slid to their places over the newly made declivities4 ,the publication of the famous 8,etudes sur les ,glaciers0 7#ahdj71 remarkable alike for its clarity1 its sound inductions1 and wealth of illustrations1 brought the ideas of ,agassiz more into prominence and inaugurated a #cj-years' war with the proponents of currents and icebergs4 ,the outstanding objections to the theory were the requirement of a frigid climate and the demand for glaciers of continental dimensions2 very strong objections1 indeed1 for the time when fossil evidence was not available1 the great polar ice sheets were unexplored1 and the distinction between till and waterlaid drift had not been established4 ,the glacial theory was cordially adopted by ,buckland 7#ahda7de and in part by ,lyell in ,england but viewed with suspicion by ,sedgwick1 ,whewell1 and ,mantell4 ,in ,america the response to the new idea was immediate4 ,hitchcock 7#ahda7df concludes an able discussion with the statement3 8,so remarkably does it solve most of the phenomena of diluvial action1 that ,i am constrained to believe its fundamental principles to be founded in truth40 ,the theory formed the chief topic of discussion at the third and fourth meetings of the ,association of ,american ,geologists and ,naturalists 7#ahdb1 #ahdc7 under the lead of a committee on drift consisting of ,emmons1 ,w4 ,b4 ,rogers1 ,vanuxem1 ,nicollet1 ,jackson1 and ,j4 ,l4 ,hayes4 ,the result of these discussions was a curious reaction4 ,hitchcock complained that he 8had been supposed to be an advocate for the unmodified glacial theory1 but he had never been a believer in it10 and ,jackson spoke for a number of men when he stated3#dg 8,this country exhibits no proofs of the glacial theory as taught by ,agassiz but on the contrary the general bearing of the facts is against that theory4444 ,many eminent men incautiously embraced the new theory1 which within two or three years from its promulgation1 had been found utterly inadequate1 and is now abandoned by many of its former supporters40 ,out of this symposium came also the strange contribution of ,h4 ,d4 ,rogers 7#ahdd71dh who cast aside the teachings of deduction and observation and returned to the views of the ,medievalists4 8,if we will conceive1 then1 a wide expanse of waters1 less perhaps than one thousand feet in depth1 dislodged from some high northern or circumpolar basin1 by a general lifting of that region of perhaps a few hundred feet1 and an equal subsidence of the country south1 and imagine this whole mass converted by earthquake pulsations of the breadth which such undulations have1 into a series of stupendous and rapid-moving waves of translation1 helped on by the still more rapid flexures of the floor over which they move1 and then advert to the shattering and loosening power of the tremendous jar of the earthquake1 we shall have an agent adequate in every way to produce the results we see1 to float the northern ice from its moorings1 to rip off1 assisted with its aid1 the outcrops of the hardest strata1 to grind up and strew wide their fragments1 to scour down the whole rocky floor1 and1 gathering energy with resistance1 to sweep up the slopes and over the highest mountains40 ,because of the prominence of their author1 ,rogers's views exerted some influence and seemingly received support from ,england through the elaborate mathematic discussions of ,whewell 7#ahdh71 who considered the drift as 8irresistible proof of paroxysmal action10 and ,hopkins 7#aheb71 who contended for 8currents produced by repeated elevatory movements40 ,after his arrival in ,america 7#ahdf71 ,agassiz's influence was felt1 and his paper on the erratic phenomena about ,lake ,superior 7#ahej71di in which he called upon the advocates of water-borne ice to point out the barrier which caused the current to subside1 produced a salutary effect2 yet ,desor 7#aheb7ej states that in the region described by ,agassiz 8the assumption of a general ice cap is no longer admissible10 and that the bowlders on ,long ,island 8were transported on ice rafts along the sea shore and stranded on the ridges and eminences which were then shoals along the coast40 ,twenty years of discussion were insufficient to establish the glacial theory either in ,europe or ,america4 ,the consensus of opinion among the more advanced thinkers in #ahfj is expressed by ,dana3#ea 8,in view of the whole subject1 it appears reasonable to conclude that the ,glacier theory affords the best and fullest explanation of the phenomena over the general surface of the continents1 and encounters the fewest difficulties4 ,but icebergs have aided beyond doubt in producing the results along the borders of the continents1 across ocean-channels like the ,german ,ocean and the ,baltic1 and possibly over great lakes like those of ,north ,america4 ,long ,island ,sound is so narrow that a glacier may have stretched across it40 ,papers in the ,journal of #ahfj-gj show a prevailing belief in icebergs1 but the evidence for land ice was accumulating as the deposits became better known1 and in #ahga field workers speak in unmistakable tones3#eb 8,it is still a mooted question in ,american geology whether the events of the ,glacial era were due to glaciers or icebergs4444 ,american geologists are still divided in opinion1 and some of the most eminent have pronounced in favor of icebergs4 ,since1 then1 icebergs cannot pick up masses tons in weight from the bottom of a sea1 or give a general movement southward to the loose material of the surface2 neither can produce the abrasion observed over the rocks under its various conditions2 and inasmuch as all direct evidence of the submergence of the land required for an iceberg sea over ,new ,england fails1 the conclusion appears inevitable that icebergs had nothing to do with the drift of the ,new ,haven region1 in the ,connecticut valley2 and1 therefore1 that the ,glacial era in central ,new ,england was a ,glacier era40 ,matthew 7#ahga7ec reached the same conclusion for the ,lower ,provinces of ,canada4 ,in spite of the increasing clarity of the evidence1 the battle for the glacial theory was not yet won4 ,the remaining opponents though few in number were distinguished in attainments4 ,dawson clung to the outworn doctrine until his death in #ahii4 ,an interesting feature of the history of glacial theories is the calculation by ,maclaren 7#ahdb7ed that the amount of water abstracted from the seas to form the hypothetical ice sheet would lower the ocean level #cej feet--an early form of the glacial control hypothesis 7see ,daly#ee74 ,extent of ,glacial ,drift4 ,by the middle of the nineteenth century1 it was recognized that the 8drift10 whatever its origin1 was not of world-wide extent4 ,in ,america its characteristic features were found best developed north of latitude #dj degrees2 in ,europe1 the ,alps1 the ,scottish ,highlands1 and ,scandinavia were recognized as type areas4 ,the limits were unassigned1 partly because the field had not been surveyed1 but largely because criteria for the recognition of drift had not been established4 ,the well-known hillocks and ridges of 8diluvium0 and 8alluvium0 and 8drift0 of ,new ,jersey and ,ohio1 and the mounds of the ,missouri ,cotou elaborately described by ,catlin 7#ahdj7ef bore little resemblance to the walls of unsorted rock which stand as moraines bordering ,alpine glaciers4 ,the ,orange sand of ,mississippi was included in the drift by ,hilgard 7#ahff71eg and the gravels at ,philadelphia by ,hall 7#ahgf74eh ,stevens 7#ahgc7ei described trains of glacial erratics at ,richmond1 ,virginia1 and ,william ,b4 ,rogers 7#ahgf7fj accounts for certain deposits in the ,potomac1 ,james1 and ,roanoke rivers by the presence of ,pleistocene ice tongues or swollen glacial rivers1 and remarks3 8,it is highly probable that glacial action had much to do with the original accumulation of the rocky debris on the flanks of the ,blue ,ridge1 and in the ,appalachian valleys beyond40 ,kerr 7#ahha7fa referred the ancient erosion surface of the ,piedmont belt in ,north ,carolina to glacial denudation1 ,de la ,beche compared the drift of ,jamaica with that of ,new ,england1 and ,agassiz interpreted soils of ,brazil as glacial4 ,the first detailed description and unequivocal interpretation of either terminal or recessional moraines is from the pen of ,gilbert 7#ahga71fb geologist of the ,ohio ,survey4 ,in discussing the former outlet of ,lake ,erie through the ,fort ,wayne channel1 ,gilbert writes3 8,the page of history recorded in these phenomena is by no means ambiguous4 ,the ridges1 or1 more properly1 the ridge which determines the courses of the ,st4 ,joseph and ,st4 ,marys rivers is a buried terminal moraine of the glacier that moved southwestward through the ,maumee valley4 ,the overlying ,erie ,clay covers it from sight1 but it is shadowed forth on the surface of that deposit1 as the ground is pictured through a deep and even canopy of snow4 ,its irregularly curved outline accords intimately with the configuration of the valley1 and with the direction of the ice markings2 its concavity is turned toward the source of motion2 its greatest convexity is along the line of least resistance4 ,south of the ,st4 ,marys river are other and numerous moraines accompanied by glacial stri4 ,their character and courses have not yet been studied2 but their presence carries the mind back to an epoch of the cold period1 when the margin of the icefield was farther south1 and the glacier of the ,maumee valley was merged in the general mass4 ,as the mantle of ice grew shorter--and1 in fact1 at every stage of its existence--its margin must have been variously notched and lobed in conformity with the contour of the country1 the higher lands being first laid bare by the encroaching secular summer4 ,early in the history of this encroachment the glacier of the ,maumee valley constituted one of these lobes1 and has recorded its form in the two moraines that ,i have described40 ,three years after the recognition of moraines in the ,maumee valley1 ,chamberlin 7#ahgd7fc showed that the seemingly disorganized mounds and basins and ridges known as the ,kettle range of ,wisconsin is the terminal moraine of the ,green ,bay glacier4 ,at an earlier date 7#ahfd7 ,whittlesey interpreted the kettles of the ,wisconsin moraine as evidence of ice blocks from a melting glacier and presented a map showing the 8southern limit of boulders and coarse drift40 ,in #ahgf attention was called to the terminal moraine of ,new ,england by ,g4 ,frederick ,wright1 who assigns the honor of discovery to ,clarence ,king4 ,illustration3 ,g ,k ,gilbert ,with the observations of ,gilbert1 ,chamberlin1 and ,king in mind1 the terminal moraine was traced by various workers across the ,united ,states and into ,canada and the extent of glacial cover revealed4 ,following #ahge the pages of the ,journal contain many contributions dealing with the origin and structure of moraines1 eskers1 kames1 and drumlins4 ,before #ahij twenty-eight papers on the glacial phenomena of the ,erie and ,ohio basin alone had appeared4 ,by #aijj substantial agreement had been reached regarding the significant features of the drift1 the outline history of the ,great ,lakes had been written1 and the way had been paved for stratigraphic studies of the ,pleistocene1 which bulk large in the pages of the ,journal for the last two decades4 ,epochs of ,glaciation4 ,for a decade following the general acceptance of the glacial origin of 8diluvium10 the deposits were embraced as 8drift0 and treated as the products of one long period of glacial activity1 and throughout the controversy of iceberg and glacier the unity of the glacial period was unquestioned4 ,beds of peat and fossiliferous lacustrine deposits in ,switzerland1 ,england1 and in ,america and the recognition of an 8upper0 and a 8lower0 diluvium by ,scandinavian geologists suggested two epochs1 and as the examples of such deposits increased in number and it became evident that the plant fossils represented forms demanding a genial climate and that the phenomena were seen in many countries1 the belief grew that minor fluctuations or gradual recession of an ice sheet were inadequate to account for the phenomena observed4 ,it is natural that this problem should have found its solution in ,america1 where the ,pleistocene is admirably displayed1 and where the ,state and ,federal surveys were actively engaged in areal mapping4 ,in #ahhc ,chamberlin#fd presented his views under the bold title1 8,preliminary ,paper on the ,terminal ,moraine of the ,second ,glacial ,epoch10 and the existence of deposits of two or more ice sheets and the features of interglacial periods were substantially established by the interesting debate in the ,journal led by ,chamberlin1 ,wright1 ,upham and ,dana4#fe ,contributions since #ahie have been concerned with the degree rather than the fact of complexity1 and continued study has resulted in the general recognition of five glacial stages in ,north ,america and four in ,europe4 ,the ,loess as a ,glacial ,deposit4 ,a curious side-product of the study of glaciation in ,north ,america is the controversy over the origin of loess4 ,the interest aroused is indicated by scores of papers in ,american periodicals and ,state reports of the last quarter of the #aith century--papers which bear the names of prominent geologists4 ,the 8loess0 in the valley of the ,rhine had long been known1 but the subject assumed prominence by the publication in #ahff of ,pumpelly's ,travels in ,china4#ff ,wide-spread deposits #bjj to #a1jjj feet thick were described as very fine-grained yellowish earth of distinctive structure without stratification but penetrated by innumerable tubes and containing land or fresh-water shells4 ,pumpelly considered these deposits lacustrine1 a view which found general acceptance though combated by ,kingsmill 7#ahga71fg who argued for marine deposition4 ,baron ,von ,richthofen's classic on ,china1 which appeared in #ahgg1 amplifies the observations of ,pumpelly and marshals the evidence to support the hypothesis that the loess is wind-laid both on dry land and within ancient salt lakes4 ,the conclusions of ,von ,richthofen were adopted by ,pumpelly whose knowledge of the ,chinese deposits1 supplemented by studies in ,missouri1 of which ,state he was director of the ,geological ,survey in #ahgb-gc1 placed him in position to form a correct judgment4 ,he says3#fh 8,recognizing from personal observation the full identity of character of the loess of northern ,china1 ,europe and the ,missouri ,valley1 ,i am obliged to reject my own explanation of the origin of the ,chinese deposits1 and to believe with ,richthofen that the true loess1 wherever it occurs1 is a sub-aerial deposit1 formed in a dry central region1 and that it owes its structure to the formative influence of a steppe vegetation4 ,the one weak point of ,richthofen's theory is in the evident inadequacy of the current disintegration as a source of material4 ,when we consider the immense area covered by loess to depths varying from #ej to #b1jjj feet1 and the fact that this is only the very finest portion of the product of rock-destruction1 and again that the accumulation represents only a very short period of time1 geologically speaking1 surely we must seek a more fertile source of supply than is furnished by the current decomposition of rock surface4 ,it seems to me that there are two important sources3 ,i4 ,the silt brought by rivers1 many of them fed by the products of glacial attrition flowing from the mountains into the central region4 ,where the streams sink away1 or where the lakes which receive them have dried up1 the finer products of the erosion of a large territory are left to be removed in dust storms4 ,,ii4 ,the second 444 source is the residuary products of a secular disintegration40 ,the evidence presented by ,pumpelly for the eolian origin of loess--structure1 texture1 composition1 fossil content and topographic position--is complete1 and to him belongs the credit for the correct interpretation of the ,mississippi valley deposits4 ,unfortunately his contribution came at a time when the geologists of the central ,states were intent on tracing the paths and explaining the work of ,pleistocene glaciers1 and the belief was strong that loess was some phase of glacial work4 ,its position at the border of the ,iowan drift so obviously suggests a genetic relation that the fossil evidence of steppe climate suggested by ,binney in #ahdhfi was minimized4 ,students of ,pleistocene geology in ,minnesota1 ,iowa1 ,nebraska1 ,missouri1 although less vigorous in expression1 were substantially in agreement with ,hilgard 7#ahgi74gj 8,the sum total of anomalous conditions required to sustain the eolian hypothesis partakes strongly of the marvellous40 ,the last edition of ,dana's ,manual1 #ahid1 and of ,le,conte's ,geology1 #ahif1 the two most widely used text-books of their time1 oppose the eolian theory1 and ,chamberlin1 in #ahig1ga states3 8the aqueous hypothesis seems best supported so far as concerns the deposits of the ,mississippi ,valley and western ,europe0 7p4 #gie74 ,shimek1 in papers published since #ahif has shown that aquatic and glacial conditions can not account for the loess fossils1 and the return to the views of ,pumpelly that the loess was deposited on land by the agency of wind in a region of steppe vegetation is now all but universal4 ,glacial ,sculpture4 ,within the present generation sculpture by glaciers has received much attention and has involved a reconsideration of the ability of ice to erode which in turn involves a crystallization of views of the mechanics of moving ice4 ,the evidence for glacier erosion has remained largely physiographic and rests on a study of land forms4 ,in fact1 the inadequacy of structural features or of river corrasion to account for flat-floored1 steep-walled gorges1 hanging valleys1 and many lake basins1 rather than a knowledge of the mechanics of ice has led to the present fairly general belief that glaciers are powerful agents of rock sculpture4 ,the details of the process are not yet understood4 ,erosion by glaciers enters the arena of active discussion in #ahfb-fc4 ,the possibility had been suggested by ,esmark 7#ahbg7 and by ,dana 7#ahdi7 in the description of fiords and by ,hind 7#ahee7 with reference to the origin of the ,great ,lakes4 ,it appears full-fledged in ,ramsay's classic1 which was published simultaneously in ,england and in ,america4#gb ,the argument runs as follows3 ,there is a close association of ancient glaciers and lakes especially in mountains2 glaciers are amply able to erode2 evidences of faulting1 special subsidence1 river erosion1 and marine erosion are absent from the lake basins of ,switzerland and ,great ,britain4 ,to quote ,ramsay3 8,it required a solid body grinding steadily and powerfully in direct and heavy contact with and across the rocks to scoop out deep hollows1 the situations of which might either be determined by unequal hardness of the rocks1 by extra weight of ice in special places1 or by accidental circumstances1 the clue to which is lost from our inability perfectly to reconstruct the original forms of the glaciers40 8,i believe with the ,italian geologists1 that all that the glaciers as a whole effected was only slightly to deepen these valleys and materially to modify their general outlines1 and1 further 7a theory ,i am alone responsible for71 to deepen them in parts more considerably when1 from various causes1 the grinding power of the ice was unusually powerful1 especially where1 as in the lowlands of ,switzerland1 the ,miocene strata are comparatively soft40 ,whittlesey 7#ahfd7gc considered that the rock-bound lakes and narrow bays near ,lake ,superior were partly excavated by ice4 ,le,conte 7#ahge7gd records some significant observations in a pioneer paper on glacier erosion which has not received adequate recognition4 ,he says3 8444 ,i am convinced that a glacier1 by its enormous pressure and resistless onward movement1 is constantly breaking off large blocks from its bed and bounding walls4 ,its erosion is not only a grinding and scoring1 but also a crushing and breaking4 ,it makes by its erosion not only rock-meal1 but also large rock-chips4444 ,its erosion is a constant process of alternate rough hewing and planing4 ,if ,yosemite were unique1 we might suppose that it was formed by violent cataclysms2 but ,yosemite is not unique in form and therefore probably not in origin4 ,there are many ,yosemites4 ,it is more philosophical to account for them by the regular operation of known causes4 ,i must believe that all these deep perpendicular slots have been sawn out by the action of glaciers2 the peculiar verticality of the walls having been determined by the perpendicular cleavage structure40444 ,a lake in ,bloody ,canyon 8is a pure rock basin scooped out by the glacier at this place4444 ,these ridges separating ,hope1 ,faith1 and ,charity valleys are in fact the lips of consecutive lake basins scooped out by ice4 444 ,water tends to form deep ,v-shaped canons1 while ice produces broad valleys with lakes and meadows4444 ,i know not how general these distinctions may be1 but certainly the ,coast range of this ,state is characterized by rounded summits and ridges1 and deep ,v-shaped canons1 while the high ,sierras are characterized on the contrary by sharp1 spire-like1 comb-like summits1 and broad valleys2 and this difference ,i am convinced is due in part at least to the action of water on the one hand1 and of ice on the other40 ,king 7#ahgh7ge assigned to glacial erosion a commanding position in mountain sculpture4 ,in regard to the ,uintas1 he says3 8,glacial erosion has cut almost vertically down through the beds carving immense amphitheatres with basin bottoms containing numerous ,alpine lakes4444 ,post-glacial erosion has done an absolutely trivial work4 ,there is not a particle of direct evidence1 so far as ,i can see1 to warrant the belief that these ,u-shaped canons were given their peculiar form by other means than the actual ploughing erosion of glaciers44440 ,these contributions from the ,cordilleras corroborating the conclusions of ,ramsay 7#ahfb71 ,tyndall 7#ahfb71 ,jukes 7#ahfb71 ,hector 7#ahfc71 ,logan 7#ahfc71 ,close 7#ahgj71 and ,james ,geikie 7#ahge71 made little impression4 ,the views of ,lyell 7#ahcc71 ,ball 7#ahfc71 ,j4 ,w4 ,dawson 7#ahfd71 ,falconer 7#ahfd71 ,studer 7#ahfd71 ,murchison 7#ahfd1 #ahgj71 ,ruskin 7#ahfe71 ,rutimeyer 7#ahfi71 ,whymper 7#ahga71 ,bonney 7#ahgc71 ,pfaff 7#ahgd71 ,gurlt 7#ahgd71 ,judd 7#ahgf71 prevailed1 and the conclusions of ,davis in #ahhbgf fairly expressed the prevailing belief in ,europe and in ,america3 8,the amount of glacial erosion in the central districts has been very considerable1 but not greatly in excess of pre-glacial soils and old talus and alluvial deposits4 ,most of the solid rock that was carried away came from ledges rather than from valleys2 and glaciers had in general a smoothing rather than a roughening effect4 ,in the outer areas on which the ice advanced it only rubbed down the projecting points2 here it acted more frequently as a depositing than as an eroding agent40 ,during the past quarter-century the cleavage in the ranks of geologists1 brought about by ,ramsay's classic paper1 has remained4 ,fairchild and others in ,america1 ,heim1 ,bonney1 and ,garwood in ,europe argue for insignificant erosion by glaciers2 and ,gannet1 ,davis1 ,gilbert1 ,tarr in ,america followed by ,austrian workers present evidence for erosion on a gigantic scale4 ,a perusal of the voluminous literature in the ,journal and elsewhere shows that the difference of opinion is in part one of terms1 the amount of erosion rather than the fact of erosion2 it also arises from failure to differentiate the work of mountain glaciers and continental ice sheets1 of ,pleistocene glaciers and their present diminished representatives4 ,the irrelevant contribution of physicists has also made for confusion4 ,it is interesting to note that the criteria for erosion of valleys by glaciers has long been established and by workers in different countries4 ,ramsay 7#ahfb7 in ,england outlined the problem and presented generalized evidence4 ,hector 7#ahfc7 in ,new ,zealand pointed out the significance of discordant drainage1 the 8hanging valleys0 of ,gilbert4 ,the ,u-form1 the broad lake-dotted floor1 and the presence of cirques and the process of plucking were probably first described by ,le,conte 7#ahgc7 in ,america4 ,the truncation of valley spurs by glaciers pointed out by ,studer in the ,kerguelen ,islands 7#ahgh7 was used by ,chamberlin 7#ahhc7 as evidence of glacial scouring4 ,conclusion4 ,during the past century many principles of land sculpture have emerged from the fog of intellectual speculation and unorganized observation and taken their place among generally accepted truths4 ,many of them are no longer subjects of controversy4 ,erosion has found its place as a major geologic agent and has given a new conception of natural scenery4 ,lofty mountains are no longer 8ancient as the sun10 they are youthful features in process of dissection2 valleys and canyons are the work of streams and glaciers2 fiords are erosion forms2 waterfalls and lakes are features in process of elimination2 many plains and plateaus owe their form and position to long-continued denudation4 ,modern landscapes are no longer viewed as original features or the product of a single agent acting at a particular time1 but as ephemeral forms which owe their present appearance to their age and the particular forces at work upon them as well as to their original structure4 ,it is interesting to note the halting steps leading to the present viewpoint1 to find that decades elapsed between the formulation of a theory or the recording of significant facts and their final acceptance or rejection1 and to realize that the organization of principles and observations into a science of physiography has been the work of the present generation4 ,progress has been conditioned by a number of factors besides the intellectual ability of individual workers4 ,the influence of locality is plainly seen4 ,convincing evidence of river erosion was obtained in central ,france1 the ,pacific ,islands1 and the ,colorado ,plateau--regions in which other causes were easily eliminated4 ,sculpture by glaciers passed beyond the theoretical stage when the simple forms of the ,sierras and ,new ,zealand ,alps were described4 ,the origin of loess was first discerned in a region where glacial phenomena did not obscure the vision4 ,the complexity of the ,glacial period asserted by geologists of the ,middle ,west was denied by eastern students4 ,the work of waves on the ,english coast impressed ,british geologists to such an extent that plains of denudation and inland valleys were ascribed to ocean work4 ,in the establishment of principles1 the friendly interchange of ideas has yielded large returns4 ,many of the fundamental conceptions of earth sculpture have come from groups of men so situated as to facilitate criticism4 ,it is impossible1 even if desirable1 to award individual credit to ,venetz1 ,charpentier1 and ,agassiz in the formulation of the glacial theory2 and the close association of ,agassiz and ,dana in ,new ,england and of ,chamberlin and ,irving in ,wisconsin was undoubtedly helpful in establishing the theory of continental glaciation4 ,from the intimate companionship in field and laboratory of ,hutton1 ,playfair and ,hope1 arose the profound influence of the ,edinburgh school1 and the sympathetic cooperation of ,powell1 ,gilbert1 and ,dutton has given to the world its classics in the genetic study of land forms4 ,the influence of ideas has been closely associated with clarity1 conciseness1 and attractiveness of presentation4 ,hutton is known through ,playfair1 ,agassiz's contributions to glacial geology are known to every student1 while ,venetz1 ,charpentier1 and ,hugi are only names4 ,cuvier's discourses on dynamical geology were reprinted and translated into ,english and ,german1 but ,lamarck's 8,hydrogologie0 is known only to book collectors4 ,the verbose works of ,guettard1 although carrying the same message as ,playfair's 8,illustrations0 and ,desmarest's 8,memoirs10 are practically unknown1 as is also ,horace ,h4 ,hayden's treatise 7#ahba7 on the drift of eastern ,north ,america4 ,it has been well said that the world-wide influence of ,american physiographic teaching is due in no small part to the masterly presentations of ,gilbert and ,davis4 ,it is surprising to note the delays1 the backward steps1 and the duplication of effort resulting from lack of familiarity with the work of the pioneers4 ,sabine says in #ahfd3gg 8,it often happens1 not unnaturally1 that those who are most occupied with the questions of the day in an advancing science retain but an imperfect recollection of the obligations due to those who laid the first foundations of our subsequent knowledge40 ,the product of intellectual effort appears to be conditioned by time of planting and character of soil as well as by quantity of seed4 ,for example3 ,erosion by rivers was as clearly shown by ,desmarest as by ,dana and ,newberry #ej years later4 ,criteria for the recognition of ancient fluviatile deposits were established by ,james ,deane in #ahdg in a study of the ,connecticut ,valley ,triassic4 ,agassiz's proof that ice is an essential factor in the formation of till is substantially a duplication of ,dobson's observations 7#ahbf74 ,the volumes of the ,journal with their very large number of articles and reviews dealing with geology show that the interpretation of land forms as products of subarial erosion began in ,france and ,french ,switzerland during the later part of the eighteenth century as a phase of the intellectual emancipation following the ,revolution4 ,scotland and ,england assumed the leadership for the first half of the nineteenth century1 and the first #ajj volumes of the ,journal show the profound influence of ,english and ,french teaching4 ,in ,america1 independent thinking1 early exercised by the few1 became general with the establishment of the ,federal survey1 the increase in university departments1 geological societies and periodicals1 and has given to ,americans the responsibilities of teachers4 ,bibliography4 7,in the following list 8this ,journal0 refers to the ,american ,journal of ,science47 ,footnote #d3 ,wilson1 ,j4 ,w41 ,bursting of lakes through mountains1 this ,journal1 #c1 #bec1 #ahba4 ,footnote #e3 ,whitney1 ,j4 ,d41 ,progress of the ,geological ,survey of ,california1 this ,journal1 #ch1 #bfc-bfd1 #ahfd4 ,footnote #f3 ,playfair1 ,john1 ,illustrations of the ,huttonian theory of the earth1 ,edinburgh1 #ahjb4 ,footnote #g3 ,kain1 ,j4 ,h41 ,remarks on the mineralogy and geology of northwestern ,virginia and eastern ,tennessee1 this ,journal1 #a1 #fj-fg1 #ahai4 ,footnote #h3 ,hitchcock1 ,edward1 ,geology1 etc41 of regions contiguous to the ,connecticut1 this ,journal1 #g1 #a-cj1 #ahbd4 ,footnote #i3 ,buckland1 ,wm41 ,reliqui diluvian1 this ,journal1 #h1 #aej1 #cag1 #ahbd4 ,footnote #aj3 ,phillips1 ,john1 ,geology of ,yorkshire1 this ,journal1 #ba1 #ag-bj1 #ahcb4 ,footnote #aa3 ,scrope1 ,g4 ,p41 ,excavation of valleys1 ,geol4 ,soc41 ,london1 ,no4 #ad1 #ahcj4 ,footnote #ab3 ,hayes1 ,g4 ,e41 ,remarks on geology and topography of western ,new ,york1 this ,journal1 #ce1 #hh-ia1 #ahci4 ,footnote #ac3 ,seventh ,meeting of the ,british ,association for the ,advancement of ,science1 this ,journal1 #cc1 #bhh1 #ahch4 ,footnote #ad3 ,darwin1 ,charles1 ,geological observations on the volcanic islands and parts of ,south ,america1 etc41 second part of the ,voyage of the 8,beagle10 during #ahcb-ahcf4 ,london1 #ahdd4 ,footnote #ae3 ,hildreth1 ,s4 ,p41 ,observations1 etc41 valley of the ,ohio1 this ,journal1 #bi1 #a-adh1 #ahcf4 ,footnote #af3 ,geddes1 ,james1 ,observations on the geological features of the south side of ,ontario valley1 this ,journal1 #aa1 #bac-bah1 #ahbf4 ,footnote #ah3 ,warren1 ,g4 ,k41 ,preliminary report of explorations in ,nebraska and ,dakota1 this ,journal1 #bg1 #chj1 #ahei4 ,footnote #ai3 ,lesley1 ,j4 ,p41 ,observations on the ,appalachian region of southern ,virginia1 this ,journal1 #cd1 review1 #dac-dae1 #ahfb4 ,footnote #ag3 ,conrad1 ,t4 ,a41 ,notes on ,american geology1 this ,journal1 #ce1 #bcg-bea1 #ahci4 ,footnote #bj3 ,dana1 ,j4 ,d41 ,on denudation in the ,pacific1 this ,journal1 #i1 #dh-fb1 #ahej4 ----1 ,on the degradation of the rocks of ,new ,south ,wales and formation of valleys1 this ,journal1 #i1 #bhi-bid1 #ahej4 ,footnote #ba3 ,hubbard1 ,o4 ,p41 ,on the condition of trap dikes in ,new ,hampshire an evidence and measure of erosion1 this ,journal1 #i1 #aeh-aga1 #ahej4 ,footnote #bb3 ,hayden1 ,f4 ,v41 ,some remarks in regard to the period of elevation of the ,rocky ,mountains1 this ,journal1 #cc1 #cje-cac1 #ahfb4 ,footnote #bc3 ,newberry1 ,j4 ,s41 ,colorado ,river of the ,west1 this ,journal1 #cc1 review1 #chg-djc1 #ahfb4 ,footnote #bd3 ,jukes1 ,j4 ,b41 ,address to the ,geological ,section of the ,british ,association at ,cambridge1 ,quart4 ,jour4 ,geol4 ,soc41 #ah1 #ahfb1 this ,journal1 #cd1 #dci1 #ahfb4 ,footnote #be3 ,powell1 ,j4 ,w41 ,exploration of the ,colorado ,river of the ,west1 #ahge4 ,for ,powell's preliminary article see this ,journal1 #e1 #def-dfe1 #ahgc4 ,footnote #bf3 ,mc,gee1 ,w4 ,j41 ,three formations of the ,middle ,atlantic slope1 this ,journal1 #ce1 #abj1 #cbh1 #cfg1 #ddh1 #ahhh4 ,footnote #bg3 ,davis1 ,w4 ,m41 ,topographic development of the ,triassic formation of the ,connecticut ,valley1 this ,journal1 #cg1 #dbc-dcd1 #ahhi4 ,footnote #bh3 ,percival1 ,j4 ,g41 ,geology of ,connecticut1 #ahdb4 ,footnote #bi3 ,kerr1 ,w4 ,c41 ,origin of some new points in the topography of ,north ,carolina1 this ,journal1 #ba1 #baf-bai1 #ahha4 ,footnote #cj3 ,mc,gee1 ,w4 ,j41 ,the classification of geographic forms by genesis1 ,nat4 ,geogr4 ,mag41 #a1 #bg-cf1 #ahhh4 ,footnote #ca3 ,davis1 ,w4 ,m41 ,the rivers and valleys of ,pennsylvania1 ,nat4 ,geogr4 ,mag41 #a1 #ahc-bec1 #ahhi4 ----1 ,the rivers of northern ,new ,jersey with notes on the classification of rivers in general1 ibid41 #b1 #ha-aaj1 #ahij4 ,footnote #cb3 ,silliman1 ,benjamin1 ,notice of ,horace ,h4 ,hayden's geological essays1 this ,journal1 #c1 #di1 #ahba4 ,footnote #cc3 ,cornelius1 ,elias1 ,account of a singular position of a granite rock1 this ,journal1 #b1 #bjj-bja1 #ahbj4 ,footnote #cd3 ,finch1 ,john1 ,on the ,celtic antiquities of ,america1 this ,journal1 #g1 #adi-afa1 #ahbd4 ,footnote #ce3 ,finch1 ,john1 ,geological essay on the ,tertiary formations in ,america1 this ,journal1 #g1 #ca-dc1 #ahbd4 ,footnote #cf3 ,conybeare and ,phillips1 ,outlines of the geology of ,england and ,wales1 this ,journal1 #g1 #baj1 #baa1 #ahbd4 ,footnote #cg3 ,hayden1 ,horace ,h41 ,geological essays1 #a-dab1 #ahba1 this ,journal1 #c1 #dg-eg1 #ahba4 ,footnote #ch3 ,jackson1 ,c4 ,t41 ,reports on the geology of the ,state of ,maine1 and on the public lands belonging to ,maine and ,massachusetts1 this ,journal1 #cf1 #aec1 #ahci4 ,footnote #ci3 ,gibson1 ,j4 ,b41 ,remarks on the geology of the lakes and the valley of the ,mississippi1 this ,journal1 #bi1 #bja-bac1 #ahcf4 ,footnote #dj3 ,phillips1 ,john1 ,geology of ,yorkshire1 this ,journal1 #ba1 #ad-ae1 #ahcb4 ,footnote #da3 ,granger1 ,ebenezer1 ,notice of a curious fluted rock at ,sandusky ,bay1 ,ohio1 this ,journal1 #f1 #ahj1 #ahbc4 ,footnote #db3 ,dobson1 ,peter1 ,remarks on bowlders1 this ,journal1 #aj1 #bag-bah1 #ahbf4 ,footnote #dc3 ,murchison1 ,r4 ,i41 ,address at anniversary meeting of the ,geological ,society of ,london1 this ,journal1 #dc1 #bjj-bja1 #ahdb4 ,footnote #dd3 ,peter ,dobson 7#aghd-ahgh7 came to this country from ,preston1 ,england1 in #ahji and established a cotton factory at ,vernon1 ,conn4 ,footnote #de3 ,buckland1 ,w41 ,on the evidence of glaciers in ,scotland and the north of ,england1 ,proc4 ,london ,geol4 ,soc41 #c1 #ahda4 ,footnote #df3 ,hitchcock1 ,edward1 ,first anniversary address before the ,association of ,american ,geologists1 this ,journal1 #da1 #bcb-bge1 #ahda4 ,footnote #dg3 ,third annual meeting of the ,association of ,american ,geologists and ,naturalists1 this ,journal1 #dc1 #aed1 #ahdb2 ,abstract of proceedings of the fourth session of the ,association of ,american ,geologists and ,naturalists1 ibid41 #de1 #cba1 #ahdc4 ,footnote #dh3 ,rogers1 ,h4 ,d41 ,address delivered before ,association of ,american ,geologists and ,naturalists1 this ,journal1 #dg1 #bge1 #ahdd4 ,footnote #di3 ,agassiz1 ,louis1 ,the erratic phenomena about ,lake ,superior1 this ,journal1 #aj1 #hc-aja1 #ahej4 ,footnote #ej3 ,desor1 ,e41 ,on the drift of ,lake ,superior1 this ,journal1 #ac1 #ic-aji1 #aheb2 ,post-,pliocene of the southern ,states1 etc41 #ad1 #di-ei1 #aheb4 ,footnote #ea3 ,dana1 ,j4 ,d41 ,manual of geology1 #edf1 ,philadelphia1 #ahfc4 ,footnote #eb3 ,dana1 ,j4 ,d41 on the ,quaternary1 or post-,tertiary of the ,new ,haven region1 this ,journal1 #a1 #a-e1 #ahga4 ,footnote #ec3 ,matthew1 ,g4 ,f41 ,surface geology of ,new ,brunswick1 this ,journal1 #b1 #cga-cgb1 #ahga4 ,footnote #ed3 ,maclaren1 ,charles1 ,the glacial theory of ,prof4 ,agassiz1 this ,journal1 #db1 #cfe1 #ahdb4 ,footnote #ee3 ,daly1 ,r4 ,a41 ,problems of the ,pacific ,islands1 this ,journal1 #da1 #aec-ahf1 #aiaf4 ,footnote #ef3 ,catlin1 ,george1 ,account of a journey to the ,cteau des ,prairies1 this ,journal1 #ch1 #ach-adf1 #ahdj4 ,footnote #eg3 ,hilgard1 ,e4 ,w41 ,remarks on the drift of the western and southern ,states and its relation to the glacier and iceberg theories1 this ,journal1 #db1 #cdc-cdg1 #ahff4 ,footnote #eh3 ,hall1 ,c4 ,e41 ,glacial phenomena along the ,kittatinny or ,blue ,mountain1 ,pennsylvania1 this ,journal1 #aa1 review1 #bcc1 #ahgf4 ,footnote #ei3 ,stevens1 ,r4 ,p41 ,on glaciers of the glacial era in ,virginia1 this ,journal1 #f1 #cga-cgc1 #ahgc4 ,footnote #fj3 ,rogers1 ,w4 ,b41 ,on the gravel and cobble-stone deposits of ,virginia and the ,middle ,states1 ,proc4 ,boston ,soc4 ,nat4 ,hist41 #ah1 #ahge2 this ,journal1 #aa1 #fj-fa1 #ahgf4 ,footnote #fa3 ,kerr1 ,w4 ,c1 ,origin of some new points in the topography of ,north ,carolina1 this ,journal1 #ba1 #baf-bai1 #ahha4 ,footnote #fb3 ,gilbert1 ,g4 ,k41 ,on certain glacial and post-glacial phenomena of the ,maumee valley1 this ,journal1 #a1 #cci-cde1 #ahga4 ,footnote #fc3 ,chamberlin1 ,t4 ,c41 ,on the geology of eastern ,wisconsin1 ,geol4 of ,wisconsin1 #b1 #ahgg2 this ,journal1 #ae1 #fa1 #djf1 #ahgh4 ,footnote #fd3 ,chamberlin1 ,t4 ,c1 ,preliminary paper on the terminal moraine of the second glacial epoch1 ,u4 ,s4 ,geol4 ,survey1 ,third ,ann4 ,rept41 #bia-djb1 #ahhc4 ,footnote #fe3 ,wright1 ,g4 ,f41 ,unity of the glacial epoch1 this ,journal1 #dd1 #cea-cgc1 #ahib4 ,upham1 ,warren1 ,the diversity of the glacial drift along its boundary1 ibid41 #dg1 #ceh-cfe1 #ahid4 ,wright1 ,g4 ,f41 ,theory of an interglacial submergence in ,england1 ibid41 #dc1 #a-h1 #ahib4 ,chamberlin1 ,t4 ,c41 ,diversity of the glacial period1 ibid41 #de1 #aga-bjj1 #aihc ,dana1 ,j4 ,d41 ,on ,new ,england and the upper ,mississippi basin in the glacial period1 ibid41 #df1 #cbg-ccj1 #ahic4 ,wright1 ,g4 ,f41 ,continuity of the glacial period1 ibid41 #dg1 #afa-ahg1 #ahid4 ,chamberlin1 ,t4 ,c4 and ,leverett1 ,f41 ,further studies of the drainage features of the upper ,ohio basin1 ibid41 #dg1 #bdg-bhb1 #ahid4 ,footnote #ff3 ,pumpelly1 ,raphael1 ,geological researches in ,china1 ,japan1 and ,mongolia1 ,smithsonian ,contributions1 ,no4 #bjb1 #ahff4 ,footnote #fg3 ,kingsmill1 ,t4 ,w41 ,the probable origin of 8loess0 in ,north ,china and eastern ,asia1 ,quart4 ,jour4 ,geol4 ,soc41 #bg1 ,no4 #ajh1 #ahga4 ,footnote #fh3 ,pumpelly1 ,raphael1 ,the relation of secular rock-disintegration to loess1 glacial drift and rock basins1 this ,journal1 #ag1 #ace1 #ahgi4 ,footnote #fi3 ,binney1 ,a41 ,some geologic features at ,natchez on the ,mississippi ,river1 ,proc4 ,boston ,soc4 ,nat4 ,hist41 #b1 #abf-acj1 #ahdh4 ,footnote #gj3 ,hilgard1 ,e4 ,w41 ,the loess of ,mississippi ,valley1 and the eolian hypothesis1 this ,journal1 #ah1 #ajf-aab1 #ahgi4 ,footnote #ga3 ,chamberlin1 ,t4 ,c1 ,supplementary hypothesis respecting the origin of the loess of the ,mississippi ,valley1 ,jour4 ,geol41 #e1 #gie-hjb1 #ahig4 ,footnote #gb3 ,ramsay1 ,a4 ,c41 ,on the glacial origin of certain lakes in ,switzerland1 the ,black ,forest1 ,great ,britain1 ,sweden1 ,north ,america1 and elsewhere1 ,quart4 ,jour4 ,geol4 ,soc41 #ahfb2 this ,journal1 #ce1 #cbd-cde1 #ahfc4 ,preliminary statements of this theory appeared in #ahei and #ahfj4 ,footnote #gc3 ,whittlesey1 ,charles1 ,smithsonian ,contributions1 ,no4 #aig1 #ahfd4 ,footnote #gd3 ,le,conte1 ,joseph1 ,on some of the ancient glaciers of the ,sierras1 this ,journal1 #e1 #cbe-cdb1 #ahgc1 #aj1 #abf-aci1 #ahge4 ,footnote #ge3 ,king1 ,clarence1 ,u4 ,s4 ,geol4 ,expl4 #djth ,par41 #a1 #dei-ebi1 #ahgh4 ,footnote #gf3 ,davis1 ,w4 ,m41 ,glacial erosion1 ,proc4 ,boston ,soc4 ,nat4 ,hist41 #bb1 #eh1 #ahhb4 ,footnote #gg3 ,sabine1 ,sir ,edward1 ,address of the president of the ,royal ,society1 this ,journal1 #cg1 #ajh1 #ahfd4 ,,iv ,a ,,century ,,of ,,geology4--,,the ,,growth ,,of ,,knowledge ,,of ,,earth ,,structure ,by ,,joseph ,,barrell ,introduction ,the ,intellectual ,viewpoint in #ahah4 ,in #ahah1 the year of the founding of the ,journal1 the natural sciences were still in their infancy in ,europe4 ,geology was still subordinate to mineralogy1 was hardly recognized as a distinct science1 and consisted in little more than a description of the character and distribution of minerals and rocks4 ,america was remote from the ,old ,world centers of learning4 ,the energy of the young nation was absorbed in its own expansion1 and but a few of those who by aptitude were fitted to increase scientific knowledge were even conscious of the existence of such a field of endeavor4 ,under these circumstances the educative field open to a journal of science in the ,united ,states was an almost virgin soil4 ,original contributions could most readily be based upon the natural history of the ,new ,world1 and the founder of the ,journal showed insight appreciative of the situation in stating in the 8,plan of the ,work0 in the introduction to the first volume that 8,it will be a leading object to illustrate ,,american ,,natural ,,history1 and especially our ,,mineralogy and ,,geology40 ,at this time educated people were still satisfied that the whole knowledge of the origin and development of the earth so far as man could or should know it was embraced in the ,book of ,genesis4 ,they were inclined to look with misgiving at attempts to directly interrogate the earth as to its history4 ,philosophers such as ,descartes and ,liebnitz1 the cosmogonists de ,maillet and ,buffon had been less instrumental in developing science than in fitting a few facts and many speculations to their systems of philosophy4 ,by the opening of the nineteenth century1 however1 men of learning were coming to appreciate that the way to advance science was to experiment and observe1 to collect facts and discourage unfounded speculation4 ,silliman's insight into the needs of geologic science is shown in the following quotation 7#a1 pp4 #f1 #g1 #ahah73 8,our geology1 also1 presents a most interesting field of inquiry4 ,a grand outline has recently been drawn by ,mr4 ,maclure1 with a masterly hand1 and with a vast extent of personal observation and labour3 but to fill up the detail1 both observation and labour still more extensive are demanded2 nor can the object be effected1 till more good geologists are formed1 and distributed over our extensive territory4 ,to account for the formation and changes of our globe1 by excursions of the imagination1 often splendid and imposing1 but usually visionary1 and almost always baseless1 was1 till within half a century1 the business of geological speculations2 but this research has now assumed a more sober character2 the science of geology has been reared upon numerous and accurate observations of facts2 and standing thus upon the basis of induction1 it is entitled to a rank among those sciences which ,lord ,bacon's ,philosophy has contributed to create4 ,geological researches are now prosecuted by actually exploring the structure and arrangement of districts1 countries1 and continents4 ,the obliquity of the strata of most rocks1 causing their edges to project in many places above the surface2 their exposure1 in other instances on the sides or tops of hills and mountains2 or1 in consequence of the intersection of their strata1 by roads1 canals1 and river-courses1 or by the wearing of the ocean2 or their direct perforation1 by the shafts of mines2 all these causes1 and others1 afford extensive means of reading the interior structure of the globe4 ,the outlines of ,american geology appear to be particularly grand1 simple1 and instructive2 and a knowledge of the important facts1 and general principles of this science1 is of vast practical use1 as regards the interests of agriculture1 and the research for useful minerals4 ,geological and mineralogical descriptions1 and maps of particular states and districts1 are very much needed in the ,united ,states2 and to excite a spirit to furnish them will form one leading object of this ,journal40 ,the ,prolonged ,influence of ,outgrown ,ideas4 ,those interested in any branch of science should1 as a matter of education1 read the history of that special subject4 ,a knowledge of the stages by which the present development has been attained is essential to give a proper perspective to the literature of each period4 ,much of the existing terminology is an inheritance from the first attempts at nomenclature1 or may rest upon theories long discarded4 ,popular notions at variance with advanced teaching are often the forgotten inheritance of a past generation4 ,gneiss1 trap1 and ,old ,red ,sandstone are names which we owe to ,werner4 ,the 8,tertiary period0 and 8drift0 are relics of an early terminology4 ,the geology of tourist circulars still speaks of canyons as made by 8convulsions of nature40 ,popular writers still attribute to geologists a belief in a molten earth covered by a thin crust4 ,within the present century the eighteenth century speculations of ,werner and his predecessors1 postulating a supposed capacity of water to seep through the crust into the interior of the earth1 resulting in a hypothetical progressive desiccation of the surface1 views long abandoned by most modern geologists1 have been revived by an astronomer into a theory of 8planetology40 ,a review of the literature of a century brings to light certain tendencies in the growth of science4 ,each decade has witnessed a larger accumulation of observed facts and a fuller classification of these fundamental data1 but the pendulum of interpretative theory swings away from the path of progress1 now to one side1 now to the other1 testing out the proper direction4 ,for decades the understanding of certain classes of facts may be actually retrogressive4 ,a retrospect shows that certain minds1 keen and unfettered by a prevailing theory1 have in some directions been in advance of their generation4 ,but the judgment of the times had not sufficient basis in knowledge for the separation and acceptance of their truer views from the contemporaneous tangle of false interpretations4 ,an interesting illustration of these statements regarding the slow settling of opinion may be cited in regard to the significance of the dip of the ,triassic formations of the eastern ,united ,states4 ,the strata of the ,massachusetts-,connecticut basin possess a monoclinal easterly dip which averages about #bj degrees to the east4 ,those of the ,new ,jersey-,pennsylvania-,virginia basin possess a similar dip to the northwest4 ,both basins are cut by great faults and the dip is now accepted by practically all geologists as due to rotation of the crust blocks away from a geanticlinal axis between the two basins4 ,edward ,hitchcock1 whose work from the first shows an interpretative quality in advance of his time1 states in #ahbc 7#f1gd7 regarding the dip of the ,connecticut valley rocks3 8,there is reason to believe that ,mount ,toby1 the strata of which are almost horizontal1 exhibits the original dip of these rocks1 and that those cases in which they are more highly inclined are the result of some ,plutonian convulsion4 ,such irregularity in the dip of coal fields is no uncommon occurrence40 ,in ,hitchcock's ,geology of ,massachusetts1 published in #ahcc1 ten years later1 geological structure sections of the ,connecticut ,valley rocks are given1 the facts are discussed in detail and the dip ascribed to the elevatory forces4 ,he says 7l4 c41 pp4 #bac1 #bbc73 8,if it were possible to doubt that the new red sandstone formation was deposited from water1 the surface of some of the layers of this shale would settle the question demonstrably4 ,for it exhibits precisely those gentle undulations1 which the loamy bottom of every river with a moderate current1 presents4 7,no4 #aih47 ,but such a surface could never have been formed while the layers had that high inclination to the horizon1 which many of them now present3 so that we have here1 also1 decisive evidence that they have been elevated subsequently to their deposition4444 ,the objection of a writer in the ,american ,journal of ,science1 that such a height of waters as would deposit ,mount ,toby1 must have produced a lake nearly to the upper part of ,new ,hampshire1 in the ,connecticut ,valley1 and thus have caused the same sandstone to be produced higher up that valley than ,northfield1 loses its force1 when it is recollected that this formation was deposited before its strata were elevated4 ,for the elevating force undoubtedly changed the relative level of different parts of the country4 ,in this case1 the disturbing force must have acted beneath the primary rocks4 ,and besides1 we have good evidence which will be shown by and by1 that our new red sandstone was formed beneath the ocean4 ,we cannot then reason on this subject from present levels40 ,illustration3 ,courtesy of ,popular ,science ,monthly4 ,in #ahdj1 ,h4 ,d4 ,rogers1 a geologist who has acquired a more widely known name than ,hitchcock1 but who in reality showed an inferior ability in interpretation1 made the following statements in explanation of the regional monoclinal dip of the ,new ,jersey ,triassic rocks averaging #ae to #bj degrees to the northwest3#gh 8,their materials give evidence of having been swept into this estuary1 or great ancient river1 from the south and southeast1 by a current producing an almost universal dip of the beds towards the northwest1 a feature clearly not caused by any uplifting agency1 but assumed originally at the time of their deposition1 in consequence of the setting of the current from the opposite or southeastern shore40 ,in #ahdb1 at the third annual meeting of the ,association of ,american ,geologists both ,h4 ,d4 and ,w4 ,b4 ,rogers argued 7#dc1 #agj1 #ahdb7 against ,sir ,charles ,lyell and ,e4 ,hitchcock that the present dip of the ,triassic was the original slope of deposition1 stating among other reasons that the footprints impressed upon the sediments often showed a slipping and a pushing of the soft clay in the direction of the downhill slope4 ,in #aheh ,h4 ,d4 ,rogers still held to the same views of original dip1#gi notwithstanding that a moderate amount of observation on the mud-cracked and rain-pitted layers would have supplied the proof that such must have dried as horizontal surfaces4 ,the idea of inclined deposition is not yet wholly dead as it has been suggested more than once within the present generation as a means of escaping from the necessity of accepting the very great thicknesses of this and similar formations4 ,thus1 as ,brgger has remarked in another connection1--the ghosts of the old time stand ever ready to reappear4 ,in the present essay on the rise of structural geology as reflected through a century of publication in the ,journal1 attention will be given especially to two fields1 that of structures connected with igneous rocks and that of structures connected with mountain making1 and emphasis will be placed upon the growth of understanding rather than upon the accumulating knowledge of details4 ,the growth in both of these divisions of structural geology is well illustrated in the volumes of the ,journal4 ,structures and ,relationships of ,igneous ,rocks4 ,opposed ,interpretations of ,plutonists and ,neptunists4 ,during the first quarter of the nineteenth century the geologic controversy between the ,plutonists and ,neptunists was at its height2 the ,plutonists1 following the ,scotchman1 ,hutton1 holding to the igneous origin of basalt and granite1 the ,neptunists1 after their ,german master1 ,werner of ,freiberg1 maintaining that these rocks had been precipitated from a primitive universal ocean4 ,the ,plutonists1 although time has shown them to have been correct in all essential particulars1 were for a generation submerged under the propaganda carried forward by the disciples of ,werner4 ,the 8,illustrations of the ,huttonian ,theory of the ,earth10 a remarkable classic1 worthy of being studied to-day as well as a century ago1 was published in #ahjb by ,john ,playfair1 professor of mathematics in the ,university of ,edinburgh and a friend of ,hutton1 who had died five years previously4 ,this volume was opposed by ,robert ,jameson1 professor of natural philosophy in the same university1 who had absorbed the ideas of the ,german school while at ,freiberg and published in #ahjh a volume on the 8,elements of ,geognosy10 in which the philosophy of ,werner is followed throughout and even obsidian and pumice are argued to be aqueous precipitates4 ,the authority of the ,wernerian autocracy caused its nomenclature to be adopted in the new world1 but strong evidence against its interpretations was to be found in the actual structural relations displayed by the igneous rocks4 ,contributions on ,volcanic and ,intrusive ,rocks4 ,the accumulation and study of facts constituted the best cure for an erroneous theory4 ,the publications of the ,journal contributed toward this end by articles along several lines4 ,the most original contributions were those which dealt with the areal and structural geology of eastern ,north ,america1 but equally valuable at that time for the broadening of scientific interest were the studies on the volcanic activities of the ,hawaiian ,islands1 published through many years4 ,perhaps most valuable from the educative standpoint were the extensive republications in the ,journal of the more important ,european researches1 making them accessible to ,american readers4 ,in volume #ac 7#ahbh71 for example1 a digest of ,scrope's work on volcanoes is given1 covering forty pages2 and of ,daubeny on active and extinct volcanoes1 running over seventy-five pages and extending into vol4 #ad4 ,through these comprehensive studies the nature of volcanic action became generally understood during the first half of the nineteenth century and the original publications in the ,journal were valuable in giving a knowledge of the activities of the ,hawaiian volcanoes4 ,early in the nineteenth century the whole of ,america still remained to be explored by the geologist4 ,the regions adjacent to the centers of learning were among the first to receive attention and the ,triassic basin of ,connecticut and ,massachusetts yielded information in regard to the nature of igneous intrusion4 ,this basin1 of unmetamorphic shales and sandstones1 is occupied by the ,connecticut ,river except at its southern end4 ,the ,formation contains within it sills1 dikes1 and outflows of basaltic rocks which because of their superior resistance to erosion constitute prominent hills1 in places bounded by cliffs4 ,silliman in #ahjfhj described ,east ,rock1 ,new ,haven1 ,connecticut1 as a whinstone1 trap1 or basalt1 and accounted for its presence on the supposition that it had 8actually been melted in the bowels of the earth and ejected among the superior strata by the force of subterraneous fire1 but never erupted like lava1 cooling under the pressure of the superincumbent strata and therefore compact or nonvesicular1 its present form being due to erosion40 ,in these conclusions ,silliman was correct4 ,with but a limited amount of experience he was able to discriminate between the intrusive and effusive rocks and saw that the prominence of this hill was due to the erosion of the sediments which once surrounded it4 ,an extensive paper on the geology of this region was published by ,edward ,hitchcock in #ahbc1ha then just thirty years of age4 ,this paper shows the evidence of extensive field observations1 and his comments in regard to the trap and granite are of interest4 ,hitchcock gives five pages to the subject of 8,greenstone ,dykes in ,old ,red ,sandstone0 7#f1 #ef-fj1 #ahbc7 and makes the following statements3 8,professor ,silliman conducted me to an interesting locality of these in ,east-,haven4 ,they occur on the main road from ,new-,haven to ,east-,haven1 less than half a mile from ,tomlinson's bridge 444 7p4 #ef74 ,they are an interesting feature in our geology1 and deserve more attention2 and it is peculiarly fortunate that they should be situated so near a geological school and the first mineral cabinet in our country 444 7p4 #eh74 ,origin of ,greenstone4 ,does the greenstone of the ,connecticut afford evidence in favour of the ,wernerian or of the ,huttonian theory of its origin8 ,averse as ,i feel to taking a side in this controversy1 ,i cannot but say1 that the man who maintains1 in its length and breadth1 the original hypothesis of ,werner in regard to the aqueous deposition of trap1 will find it for his interest1 if he wishes to keep clear of doubts1 not to follow the example of ,d',aubuisson1 by going forth to examine the greenstone of this region1 lest1 like that geologist1 he should be compelled1 not only to abandon his theory1 but to write a book against it4 ,indeed1 when surveying particular portions of this rock1 ,i have sometimes thought ,bakewell did not much exaggerate when he said in regard to ,werner's hypothesis1 that1 #8it is hardly possible for the human mind to invent a system more repugnant to existing facts4' ,on the other hand1 the ,huttonian would doubtless have his heart gladdened1 and his faith strengthened by a survey of the greater part of this rock4 ,as he looked at the dikes of the old red sandstone1 he would almost see the melted rock forcing its way through the fissures2 and when he came to the amygdaloidal1 especially to that variety which resembles lava1 he might even be tempted to apply his thermometer to it1 in the suspicion that it was not yet quite cool 444 7p4 #ei74 ,by treating the subject in this manner ,i mean no disrespect to any of the distinguished men who have adopted either side of this question4 ,to ,president ,cooper especially1 who regards the greenstone of the ,connecticut as volcanic1 ,i feel much indebted for the great mass of facts he has collected on the subject4 ,and were ,i to adopt any hypothesis in regard to the origin of our greenstone1 it would be one not much different from his0 7p4 #fj74 ,by #ahcc and more clearly in #ahda ,hitchcock had come to recognize the distinction between intrusive and extrusive basaltic sheets in the ,connecticut valley4 ,dawson also came to regard the ,acadian sheets as extrusive1 and ,emerson in #ahhb recalled again the evidence for ,massachusetts 7#bd1 #aie1 #ahhb74 ,davis1 however1 went a step further and by applying distinctive criteria not only separated intrusive and extrusive sheets throughout the whole ,triassic area1 but by using basalt flows as stratigraphic horizons unraveled for the first time the system of faults which cut the ,triassic system4 ,his preliminary paper 7#bd1 #cde1 #ahhb7 was followed by many others4 ,from #ahhj onward begins the period of precise structural field work4 ,the older geologists mostly conceived their work after reconnaissance methods4 ,from #ahgj to #ahhj a group of younger men entered geology who paid close attention to the solid geometry and mechanics of earth structures4 ,in their hands physical and dynamical geology began to assume the standing of a precise and quantitative science4 ,in the field of intrusive rocks the opening classic was by ,gilbert1 who in his volume on the geology of the ,henry ,mountains1 published in #ahhj1 made laccoliths known to the world4 ,with the beginning of this new period we may well leave the subject of intrusive rocks and turn to the progress of knowledge in regard to those deeper and vaster bodies now known as batholiths4 ,these1 since erosion does not expose their bottoms1 ,daly separates from intrusives and classifies as subjacent4 ,the batholiths consist typically of granite and granodiorite1 and introduce us to the problem of granite4 ,views on the ,structural ,relations of ,granite4 ,conscientious field observations were sufficient to establish the true nature of the intrusive and extrusive rocks4 ,the case was very different1 however1 with the nature and relations of the great bodies of granite1 which may be taken in the structural sense as including all the visibly crystalline acidic and intermediate rocks1 known more specifically as granite1 syenite1 and diorite4 ,the large bodies of granite1 structurally classified as stocks1 or batholiths1 commonly show wedges1 tongues1 or dike networks cutting into the surrounding rocks4 ,the relations1 however1 are not all so simple as this4 ,granites may cover vast areas1 they are usually the older rocks1 they are generally associated with regional metamorphism of the intruded formations1 which metamorphism is now understood to be due chiefly to the heat and mineralizers given off from the granite magma1 associated with mashing and shearing of the surrounding rocks4 ,the granite was often injected in successive stages which alternated with the stages of regional mashing4 ,a parallel or gneissic structure is thus developed which is in part due to mashing1 in part to igneous injection4 ,where the ascent of heat into the cover is excessive1 or where blocks are detached and involved in the magma1 the latter may dissolve some of the older cover rocks1 even where these were of sedimentary origin4 ,thus between mashing1 injection1 and assimilation the genetic relationships of a batholith to its surroundings are in many instances obscure4 ,nevertheless1 attention to the larger relations shows that the molten magma originated at great depths in the earth's crust1 far below the bottoms of geosynclines1 and consists of primary igneous material1 not of fused sediments4 ,from those depths it has ascended by various processes into the outer crust1 where it crystallized into granite masses1 to be later exposed by erosion4 ,the amount of material which can be dissolved and assimilated must be small in comparison with the whole body of the magma4 ,the original composition of the magma was probably basic1 nearer that of a basalt than that of a granite4 ,differentiation of the molten mass is thought to cause the upper and lower parts of the chamber to become unlike1 the lighter and more acidic portion giving rise to the great bodies of granite4 ,with the exception of certain border zones the whole1 however1 is regarded as igneous rock risen from the depths4 ,the complex border relations1 but more particularly certain academic hypotheses1 led to a period of misunderstanding and retrogression in regard to the nature of granites4 ,it constitutes an interesting illustration of the possibility of a wrong theory leading interpretation astray1 chiefly through the magnification of minor into major factors4 ,this history illustrates the dangers of qualitative science as compared to quantitative1 of a single hypothesis as matched against the method of multiple working hypothesis4 ,this flux of opinion in regard to the nature of granites may be traced through the volumes of the ,journal4 ,e4 ,hitchcock in #ahbd 7#f1 #ab7 noted that in places granite appeared bedded1 but in other places existed in veins which cut obliquely across the strata4 ,silliman1 although careful not to deny the aqueous origin of some basalts1 yet held that the field evidence of ,new ,england indicates for that region the igneous or ,huttonian origin of trap and granite 7#g1 #bch1 #ahbd74 ,in #ahcb the following article by ,hitchcock appeared in the ,journal 7#bb1 #a1 #gj73 ,report on the ,geology of ,massachusetts2 examined under the direction of the ,government of that ,state1 during the years #ahcj and #ahca2 by ,edward ,hitchcock1 ,prof4 of ,chemistry and ,natural ,history in ,amherst ,college4 ,a footnote adds that this is 8published in this ,journal by consent of the ,government of ,massachusetts1 and intended to appear also in a separate form1 and to be distributed among the members of the ,legislature of the same ,state1 about the time of its appearance in this work4 ,it is1 we believe1 the first example in this country1 of the geological survey of an entire ,state40 ,this article includes a geological map of the state and covers the subject of economic geology4 ,the report brought forth the following remarks from a ,french reviewer in the ,revue ,encyclopdique1 ,aug4 #ahcb1 quoted in the ,journal 7#bc1 #chi1 #ahcc73 8,a single glance at this report1 is sufficient to convince any one of the utility of such a work1 to the state which has undertaken it2 and to regret that there is so very small a part of the ,french territory1 whose geological constitution is as well known to the public1 as is now the state of ,massachusetts4 ,france has the greater cause to regret her being distanced in this race by ,america1 from her having a corps of mining engineers1 who if they had the means1 would1 in a very short time furnish a work of the same kind1 still more complete1 of each of the departments40 ,the complete report published in #ahcc is a work of #gjj pages4 ,pages #dfe to #eag are devoted to the subject of granite4 ,numerous detailed sketches are given showing contact relations4 ,nine pages are given to theoretical considerations and many lines of proof are given that granite is an igneous rock1 molten from the internal heat of the earth1 and intruded into the sedimentary strata4 ,his statement is the clearest published in the world1 so far as the writer is aware1 up to that date1 and marks ,edward ,hitchcock as one of the leading geologists of his generation in ,europe as well as ,america4 ,unfortunately his views were largely lost to sight during the following generation4 ,in #ahdj the first ,american edition of ,mantell's ,wonders of ,geology gave currency to the idea that granite is proved to be of all geological ages up to the ,tertiary 7#ci1 #f1 #ahdj74 ,in #ahdc ,j4 ,d4 ,dana pointed out 7#de1 #ajd7 that schistosity was no evidence of sedimentary origin4 ,he regarded most granites as igneous as shown by their structural relations1 but considers that some may have had a sedimentary origin4 ,rise and ,decline of the ,metamorphic ,theory of ,granite4 ,up to #ahfj granite was regarded on the basis of the facts of the field as essentially an intrusive rock1 but gneiss as a metamorphic product mostly of sedimentary origin4 ,it seemed as though sound methods of research and interpretation were securely established4 ,nevertheless1 a new era of speculation and a modified ,wernerism arose at that time with a paper by ,t4 ,sterry ,hunt1 marking a retrogression in the theory of granite which lasted until his death in #ahib4 ,in ,november1 #ahei1 ,hunt read before the ,geological ,society of ,london a paper on 8,some ,points in ,chemical ,geology0 in which he announced that igneous rocks are in all cases simply fused and displaced sediments1 the fusion taking place by the rise of the earth's internal heat into deeply buried and water-soaked masses of sediments 7see #cj1 #acc1 #ahfj74 ,the germ of this idea of aqueo-igneous fusion was far older1 due to ,babbage and ,john ,herschel1 neither of them geologists1 but such sweeping extensions of it had never before been published4 ,hunt had the advantage of a wide acquaintanceship with geological literature and chemistry4 ,he wrote plausibly on chemical and theoretical geology1 but his views were not controlled by careful field observations4 ,in fact he wrote confidently on regions which apparently he had never seen and where a limited amount of field work would have shown him to have been fundamentally in error4 ,a man of egotistical temperament1 he sought to establish priority for himself in many subjects and in order to cover the field made many poorly founded assertions4 ,building on to another ,wernerian idea1 he held that many metamorphic minerals had a chronologic value comparable to fossils--staurolite for example indicating a pre-,silurian age--and on this basis divided the crystalline rocks into five series4 ,although there is much of value buried in ,hunt's work it is difficult to disentangle it1 with the result that his writings were a disservice to the science of geology4 ,although carrying much weight in his lifetime1 they have passed with his death nearly into oblivion4 ,marcou1 with a limited knowledge of ,american geology1 and but little respect for the opinions of others1 had published a geologic map of the ,united ,states containing gross errors4 ,in support of his views he read in ,november1 #ahfa1 a paper on the ,taconic and ,lower ,silurian ,rocks of ,vermont and ,canada4 ,in the following year he was severely reviewed by 8,t10 who states positively in controverting ,marcou 7#cc1 #bhb1 #bhc1 #ahfb7 that 8the granites 7of the ,green ,mountains7 are evidently strata altered in place40 8,mr4 ,marcou should further be informed that the granites of the ,alpine summits1 instead of being1 as was once supposed1 eruptive rocks1 are now known to be altered strata of newer ,secondary and ,tertiary age4 ,a simple structure holds good in the ,british ,islands1 where as ,sir ,roderick ,murchison has shown in his recent ,geological map of ,scotland1 ,ben ,nevis and ,ben ,lawers are found to be composed of higher strata1 lying in synclinals4 ,this great law of mountain structure would alone lead us to suppose that the gneiss of the ,green mountains1 instead of being at the base1 is really at the summit of the series4444 ,we cannot here stop to discuss ,mr4 ,marcou's remark about #8the unstratified and oldest crystalline rocks of the ,white mountains' which he places beneath the lower ,taconic series4 ,mr4 ,lesley has shown that these granites are stratified1 and with ,mr4 ,hunt1 regards them as of ,devonian ,age4 7,this ,journal1 vol4 #ca1 p4 #djc47 ,mr4 ,marcou has come among us with notions of mountains upheaved by intrusive granites1 and similar antiquated traditions1 now1 happily for science1 well nigh forgotten40 ,it is seen that ,marcou1 notwithstanding the general character of his work1 happened to be nearer right in some matters than were his critics1 and that 8,t0 had adopted to the limit the views of ,hunt4 ,the recovery of geology from this period of confusion was partly owing to the slow accumulation of opposed facts2 especially to a recognition of the fact that the overplaced relation of the granite gneisses in western ,scotland was due to great overthrusts2 also to the evidence of the clearly intrusive nature of many of the ,cordilleran granites4 ,the recovery of a sounder theory was hastened1 however1 by the application of criticisms by ,j4 ,d4 ,dana in the ,journal4 ,in #ahff 7#db1 #beb7 ,dana pointed out that sedimentary rocks in ,pennsylvania1 in ,nova ,scotia1 and other regions which had been buried to a depth of at least #af1jjj feet are not metamorphic4 ,mere depth of burial of sediments was not sufficient therefore to produce metamorphism and aqueo-igneous fusion4 ,the baseless and speculative character of the use of minerals as an index of age and of ,hunt's interpretation of ,new ,england geology in general was shown by ,dana in #ahgb 7#c1 #ia74 ,the following year ,dana pointed out clearly that igneous eruptions in general have been derived from a deep-seated source and did not come from the aqueo-igneous fusion of sediments4 ,as to gradations between true igneous rocks and fused and displaced sediments he makes the following statements 7#f1 #aad1 #ahgc73 8,again1 the plastic rock-material that may be derived from the fusion or semifusion of the supercrust1 7that is1 of rocks originally of sedimentary origin17 gives rise to 8igneous0 rocks often not distinguishable from other igneous rocks1 when it is ejected through fissures far from its place of origin2 while crystalline rocks are simply metamorphic if they remain in their original relations to the associated rocks1 or nearly so4 ,between these latter igneous rocks and the metamorphic there may be indefinite gradations1 as claimed by ,hunt4 ,but if our reasonings are right1 the great part of igneous rocks can be proved to have had no such supercrust origin4 ,the argument from the presence of moisture or of hydrous minerals in such rocks in favor of their origin from the fusion of sediments has been shown to be invalid40 ,the injected marginal rocks and the post-intrusive metamorphism of most of the ,new ,england granites has1 however1 obscured more or less their real igneous nature so that the gradation from metamorphic sediments through igneous gneisses to granites could be read in either direction4 ,these features misled ,dana who accepted the prevailing idea of the general metamorphic origin of granite4 ,dana makes the following statement 7#f1 #afd1 #ahgc73 8,but ,hunt is right in holding that in general granite and syenite 7the quartz-bearing syenite7 are undoubtedly metamorphic rocks where not vein-formations1 as ,i know from the study of many examples of them in ,new ,england2 and the veins are results of infiltration through heated moisture from the rocks adjoining some part of the opened fissures they fill40 ,granite1 although regarded at this time as the extreme of the metamorphic series and originating from sediments1 was looked upon as typically ,archean in age1 though in some cases younger4 ,such a doctrine permitted such extreme misinterpretations as that of ,clarence ,king and ,s4 ,f4 ,emmons on the nature of the intrusive granite of the ,little ,cottonwood canyon in the ,wahsatch ,range4 ,this body cuts across #cj1jjj feet of ,paleozoic rocks and to the careful observer1 as later admitted by ,emmons1 shows clear evidence of its transgressive nature4 ,but at that time it was generally considered that granite mountains were capable of resisting the erosion of all geological time4 ,consequently it did not seem incredible to ,king and his associates that here a great granite range of ,archean origin had stood up through ,paleozoic time until gradual subsidence had permitted it to be buried beneath #cj1jjj feet of sediments4#hb ,it may seem to the present day reader that such a misinterpretation1 doing violence to fundamental geologic knowledge as now recognized1 was inexcusable2 but in the light of the history of geology as here detailed it is seen to have been the interpretation natural to that time4 ,it is true that a careful examination of the facts of that very field would have proved the post-,paleozoic and intrusive nature of that great granite body now known as the ,little ,cottonwood batholith1 but ,emmons has explained the rapid and partial nature of the observations which they were compelled to make in order to keep up to their schedule of progress 7#af1 #aci1 #aijc74 ,whitney had found some years earlier that the granites of the ,sierra ,nevada were igneous rocks intrusive into the ,triassic and ,jurassic strata4 ,the ,lake ,superior geologists began to show in the eighties that granite was there an intrusive igneous rock4 ,r4 ,d4 ,irving and ,wadsworth noted these relations4 ,lawson in #ahhg pointed out emphatically 7#cc1 #dgc7 that the granites of the ,rainy ,lake region1 although basal1 were younger than the schists which lay above them4 ,the granite gneisses he held were of clearly the same igneous origin as the granites and neither gave any field evidence of being fused and displaced sediments4 ,from this time forward the truly igneous nature of granite became increasingly accepted until now the notion of its being made of sedimentary rocks softened and recrystallized by the rise of the isogeotherms through deep burial is as obsolete as the still older doctrine of the ,neptunists that granite was laid down as a crystalline precipitate on the floor of the primitive ocean4 ,the recognition of the truly igneous nature of granites has been followed in the present generation by a series of studies on their structural relations and mode of genesis4 ,a number of important initial articles on various aspects of structure and contact relations have appeared in the ,journal1 but this sketch of the history of the subject may well stop with the introduction to this modern period4 ,orogenic ,structures4 ,views of ,plutonists and ,neptunists4 ,orogenic structures are1 as the name implies1 those connected with the birth of mountains4 ,nearly synonymous terms are deformative or secondary structures4 ,on a small scale this division embraces the phenomena exposed in the rock ledge or quarry face1 or in the dips and dislocations varying from one exposure to another4 ,these structures include faults1 folds1 and foliation4 ,on a larger scale are included the relations of the different ranges of a mountain system to each other1 relations to previous geologic history1 relations to the earth as a whole1 and to the forces which have generated the structures4 ,in order to see the stage of development of this subject in #ahah and its progress as reflected through the publications of a century1 more particularly in the ,journal1 it is desirable to turn again to those two treatises emanating from ,edinburgh at the beginning of the nineteenth century and representing two opposite schools of thought1 the ,plutonists and ,neptunists4 ,playfair1 in #ahjb1 devotes nineteen pages to the subject of the inflection and elevation of strata4#hc ,he places emphasis on the characteristic parallelism of the strike of the folds throughout a region1 as shown through the intersection of the folds by a horizontal plane of erosion4 ,he contrasts this with the arches shown in a transverse section and enlarges on our ability to study the deeply buried strata through the denudation of the folded structure4 ,he argues from these relations that the structures can not be explained by the vague appeal of the ,neptunists to forces of crystallization1 to slopes of original deposition1 or to sinking in of the roofs of caverns4 ,the causes he argues were heat combined with pressure4 ,as to the directions in which the pressure acted he is not altogether clear1 but apparently regards the pressure as acting in upward thrusts against the sedimentary planes1 the latter yielding as warped surfaces4 ,his method of presentation is that of inductive reasoning from facts1 but he stopped short of the conception of horizontal compression through terrestrial contraction4 ,jameson1 professor of natural history in the same university1 in #ahjh contemptuously ignores the work of ,hutton and ,playfair in what he calls the 8monstrosities known under the name of ,theories of the ,earth40 ,in a couple of pages he confuses and dismisses the whole subject of deformation4 ,he states3#hd 8,it is therefore a fact1 that all inclined strata1 with a very few exceptions1 have been formed so originally1 and do not owe their inclination to a subsequent change4 ,when we examine the structure of a mountain1 we must be careful that our observations be not too micrological1 otherwise we shall undoubtedly fail in acquiring a distinct conception of it4 ,this will appear evident when we reflect that the geognostic features of ,nature are almost all on the great scale4 ,in no case is this rule to be more strictly followed than in the examination of the stratified structure4 ,by not attending to this mode of examination1 geognosts have fallen into numberless errors1 and have frequently given to extensive tracts of country a most irregular and confused structure4 ,speculators building on these errors have represented the whole crust of the globe as an irregular and unseemly mass4 ,it is indeed surprising1 that men possessed of any knowledge of the beautiful harmony that prevails in the structure of organic beings could for a moment believe it possible1 that the great fabric of the globe itself1--that magnificent display of ,omnipotence1--should be destitute of all regularity in its structure1 and be nothing more than a heap of ruins40 ,this was the attitude of a leader of ,british opinion toward the subject of deformational geology from which the infant science had to recover before progress could be made4 ,the early maps were essentially mineralogical and lithological4 ,the order of superposition and the consequent sequence of age was regarded as settled by ,werner in ,germany and not requiring investigation in ,america4 ,the early examples of structure were sections drawn with exaggerated vertical scales and those of ,maclure do not show detail4 ,recognition of ,appalachian ,structures4 ,following the founding of the ,journal in #ahah there is observable a growth in the quality and detail of geological mapping4 ,dr4 ,aiken1 professor of natural philosophy and chemistry in ,mt4 ,st4 ,mary's ,college1 published in the ,journal in #ahcd 7#bf1 #bai7 a vertical section extending between ,baltimore and ,wheeling1 a distance of nearly #bej miles1 on a scale of about #g miles per inch4 ,the succession of rocks is carefully shown and the direction of dip1 but no attempt is made to show the underground relations1 the stratigraphic sequence1 and the folded structures which are so clear in that ,appalachian section4 ,the text also shows that the author had not recognized the folded structure4 ,furthermore1 where the folds cease at the ,alleghany mountain front1 the flat strata are shown as resting unconformably on the folded rocks to the east4 ,r4 ,c4 ,taylor1 geologist1 civil and mining engineer1 was from #ahcj to #ahce the leading student of ,pennsylvanian geology as shown by the publication in #ahce of four papers aggregating over #hj pages in the ,transactions of the ,geological ,society of ,pennsylvania4 ,his work is noticeable for accuracy in detail and no doubt was influential in setting a high standard for the state geological survey which immediately followed4 ,h4 ,d4 and ,w4 ,b4 ,rogers have been given credit in this country1 and in ,europe also1 as being the leading expounders of ,appalachian structure4 ,merrill speaks of ,h4 ,d4 ,rogers as unquestionably the leading structural geologist of his time4#he ,to the writer1 this attributed position appears to be due to his opportunities rather than to scientific acumen4 ,the magnificent but readily decipherable folded structure of ,pennsylvania1 the relationships of coal and iron to this structure1 the considerable sums of money appropriated1 and the work of a corps of able assistants were factors which made it comparatively easy to reach important results4 ,in ability to weigh facts and interpret them ,edward ,hitchcock showed much more insight than ,h4 ,d4 ,rogers1 while in the philosophic and comprehensive aspects of the subject ,j4 ,d4 ,dana far outranks him4 ,h4 ,d4 ,rogers in his first report on the geological survey of ,new ,jersey1 #ahcf1 recognizes that the ,cambro-,silurian limestones 7lower ,secondary limestones7 were deposited as nearly horizontal beds and the ridges of pre-,cambrian gneiss 7,primary7 had been pushed up as anticlinal axes 7p4 #abh74 ,he also clearly recognized the distinction between slaty cleavage and true dip as shown in the ,ordovician slates 7p4 #ig74 ,between #ahcf and #ahdj he had learned a great deal on the nature of folds as is shown in his ,pennsylvania report for #ahci and the structure sections in his ,new ,jersey report for #ahdj4 ,r4 ,c4 ,taylor1 who had now become president of the board of directors of the ,dauphin and ,susquehanna ,coal ,company1 published in the ,journal in #ahda 7#da1 #hj7 an important paper entitled 8,notice of a ,model of the ,western portion of the ,schuylkill or ,southern ,coal ,field of ,pennsylvania1 in illustration of an ,address to the ,association of ,american ,geologists1 on the most appropriate modes for representing ,geological ,phenomena40 ,in this paper he calls attention to the value of modeling as a means of showing true relations in three dimensions4 ,he condemns the custom prevalent among geologists of showing structure sections with an exaggerated vertical scale with its resultant topographic and structural distortions4 ,taylor was widely acquainted with the structure of ,pennsylvania1 ,maryland1 and ,virginia4 ,nature of ,forces ,producing ,folding4 ,in #ahbe ,dr4 ,j4 ,h4 ,steele sent to ,professor ,silliman two detailed drawings and description of an overturned fold at ,saratoga ,lake1 ,new ,york4 ,as to the significance of this feature ,steele makes the following statement 7#i1 #c1 #ahbe73 8,it is impossible to examine this locality without being strongly impressed with the belief that the position which the strata here assume could not have been effected in any other way than by a power operating from beneath upwards and at the same time possessing a progressive force2 something analogous to what takes place in the breaking up of the ice of large rivers4 ,the continued swelling of the stream first overcomes the resistance of its frozen surface and having elevated it to a certain extent1 it is forced into a vertical position1 or thrown over upon the unbroken stratum behind1 by the progressive power of the current40 ,so far as the present writer is aware this is the first recognition in geological literature of the evidence of a horizontally compressive and overturning force as a cause of folding4 ,to ,e4 ,hitchcock belongs the credit of being the first to describe overturning and inversion of strata on a large scale1 but without clearly recognizing it as such4 ,in western ,massachusetts metamorphism is extreme in the lower ,paleozoic rocks in the vicinity of the overthrust mass of ,archean granite-gneiss which constitutes the ,hoosic range4 ,the ,paleozoic rocks of the valley to the west are overturned and appear to dip beneath the older rocks4 ,farther west the metamorphism fades out and the series assumes a normal position4 ,such an inverted relation1 up to that time unknown1 is described in #ahcc as follows by ,hitchcock in his ,geology of ,massachusetts 7pp4 #big1 #bih73 8,but a singular anomaly in the superposition of the series of rocks above described1 presents a great difficulty in this case4 ,the strata of these rocks almost uniformly dip to the east3 that is1 the newer rocks seem to crop out beneath the older ones2 so that the saccharine limestone1 associated with gneiss in the eastern part of the range1 seems to occupy the uppermost place in the series4 ,now as superposition is of more value in determining the relative ages of rocks than their mineral characters1 must we not conclude that the rocks1 as we go westerly from ,hoosac mountain1 do in fact belong to older groups8 ,the petrifactions which some of them contain1 and their decidedly fragmentary character1 will not allow such a supposition to be indulged for a moment4 ,it is impossible for a geologist to mistake the evidence1 which he sees at almost every step1 that he is passing from older to newer formations1 just as soon as he begins to cross the valley of ,berkshire towards the west4 ,we are driven then to the alternative of supposing1 either that there must be a deception in the apparent outcrop of the newer rocks from beneath the older1 or that the whole series of strata has been actually thrown over1 so as to bring the newest rocks at the bottom4 ,the latter supposition is so improbable that ,i cannot at present admit it40 ,hitchcock tried to reconcile the evidence by a series of unconformities and inclined deposition1 but finds the solution unsatisfactory4 ,in this same year1 #ahcc1 ,elie de ,beaumont1 a distinguished ,french geologist1 published his theory of the origin of mountains4 ,he advanced the idea that since the globe was cooling it was condensing1 and the crust1 already cool1 must suffer compression in adjusting itself to the shrinking molten interior4 ,he concluded from the evidence shown in ,europe that the collapse of the crust occurred violently and rapidly at widely spaced intervals of time4 ,this hypothesis introduced the idea of mountain folding by horizontal compressive forces4 ,the theoretical paper of de ,beaumont1 together with further observations by ,hitchcock and others1 led the latter in #ahda to a final belief in the inversion of strata on a large scale by horizontal compression4 ,his conclusions are expressed in an important paper published in the ,journal 7#da1 #bfh1 #ahda7 and given on ,april #h1 #ahda1 as the ,first ,anniversary ,presidential ,address before the ,association of ,american ,geologists4 ,this comprehensive summary of ,american geology occupies #dc pages4 ,three pages are given to the inverted structure of the ,appalachians from which the following paragraphs may be quoted3 8,we have all read of the enormous dislocations and inversions of the strata of the ,alps2 and similar phenomena are said to exist in the ,andes4 ,will it be believed1 that we have an example in the ,united ,states on a still more magnificent scale than any yet described8444 ,let us suppose the strata between ,hudson and ,connecticut rivers1 while yet in the plastic state1 7and the supposition may be extended to any other section across this belt of country from ,canada to ,alabama17 and while only slightly elevated1 were acted upon by a force at the two rivers1 exerted in opposite directions4 ,if powerful enough1 it might cause them to fold up into several ridges2 and if more powerful along the western than the eastern side1 they might fall over so as to take an inverted dip1 without producing any remarkable dislocations1 while subsequent denudation would give to the surface its present outline4444 ,fourthly1 we should readily admit that such a plication and inversion of the strata might take place on a small scale4 ,if for instance1 we were to press against the extremities of a series of plastic layers two feet long1 they could easily be made to assume the position into which the rocks under consideration are thrown4 ,why then should we not be equally ready to admit that this might as easily be done1 over a breadth of fifty miles1 and a length of twelve hundred1 provided we can find in nature1 forces sufficiently powerful8 ,finally1 such forces do exist in nature1 and have often been in operation40 ,the advanced nature of these conceptions may be appreciated by contrasting them with those put forth by ,h4 ,d4 and ,w4 ,b4 ,rogers on ,april #bi1 #ahdb1 before the third annual meeting of the same body 7#dc1 #agg1 #ahdb7 and repeated by them before the ,british ,association at ,manchester two months later4 ,in their own words1 the ,rogers brothers from their studies on the folds shown in ,pennsylvania and ,virginia1 conceived mountain folds in general to be produced by much elastic vapor escaping through many parallel fissures formed in succession1 producing violent propulsive wave oscillations on the surface of the fluid earth beneath a thin crust4 ,thus actual billows are assumed to have rolled along through the crust4 ,they did not think tangential pressure alone could produce folds4 ,such pressures were regarded as secondary1 produced by the propagation of the waves and the only expression of tangential forces which they admitted was to fix the folds and hold them in position after the violent oscillation had subsided 7#dd1 #cfj1 #ahdc74 ,the leading ,british geologists ,de la ,beche and ,sedgwick criticized adversely this remarkable theory1 stating that they could see no such analogy in mountain folds to violent earthquake waves and that in their opinion the slow application of tangential force was sufficient to account for the phenomena 7#dd1 #cfb-cfe1 #ahdc74 ,h4 ,d4 ,rogers in the prosecution of the geological survey of ,pennsylvania displayed notable organizing ability and persistence in accomplishment1 even to advancing personally considerable sums of money1 trusting to the state legislature to later reimburse him4 ,finally1 after many delays by the state1 the publication was placed directly in his charge and he produced in #aheh a magnificent quarto work of over #a1fjj pages1 handsomely illustrated1 and accompanied by an atlas4 ,it is excellent from the descriptive standpoint1 standing in the first class4 ,measured as a contribution to the theory of dynamical geology1 the explanatory portions were1 however1 thirty years behind the times4 ,the same hypotheses are put forth in #aheh as in #ahdb4 ,there is no acceptance of the views of ,lyell concerning the uniformitarian principles expounded by this ,british leader in #ahcj1 or of the nature of orogenic forces as published by ,elie de ,beaumont in #ahcc4 ,rogers rejects the view that cleavage is due to compression and suggests 8that both cleavage and foliation are due to the parallel transmission of planes or waves of heat1 awakening the molecular forces1 and determining their direction40#hf ,thus a mere maze of words takes the place of inductive demonstrations already published4 ,in following the play of these opposing currents of geologic thought we reach now the point where a period of brilliant progress in the knowledge of mountains and of continental structures begins in the work of ,j4 ,d4 ,dana4 ,in #ahdb ,dana returned from the ,wilkes ,exploring ,expedition and the following year began the publication of the series of papers which for the next half century marked him as the leader in geologic theory in ,america4 ,his work is of course to be judged against the background of his times4 ,his papers mark distinct advances in many lines and are characterized throughout by breadth of conception and especially by clear and logical thinking4 ,his work was published very largely in the ,journal1 of which after a few years he became chief editor4 ,his first contribution on the subject of mountain structures1 entitled 8,geological results of the earth's contraction in consequence of cooling10 was published in #ahdg 7#c1 #agf74 ,the evidence of horizontal pressure was first perceived in ,france as shown by the features of the ,alps4 ,elie de ,beaumont connected it1 by means of the theory of a cooling and contracting globe1 with the other large fact of the increase of temperature with descent in the crust4 ,dana credits the ,rogers brothers with first making known the folded structures of the ,appalachians1 but objects to their interpretation of origin4 ,he showed by means of diagrams that the folds are to be explained by lateral pressure1 the direction of overturning indicating the direction from which the driving force proceeded4 ,the ,rogers brothers and especially ,james ,hall1 in working out the ,appalachian stratigraphy1 had noted that the formations1 although accumulating to a maximum thickness of between #cj1jjj and #dj1jjj feet1 showed evidences that the successive formations were deposited in shallow water4 ,it suggested to them that the weight of the accumulating sediments was the cause of subsidence1 each foot of sediment causing a foot of down sinking4 ,this idea has continued to run through various text books in geology for half a century1 yet ,dana early saw the fallacy and in #ahfc in the first edition of his ,manual of ,geology 7p4 #gag7 states 8whether this is an actual cause or not in geological dynamics is questionable40 ,in #ahff in an important article on 8,observations on the origins of some of the earth's features10 ,dana deals more fully and finally with this subject 7#db1 #bje1 #beb1 #ahff74 ,he shows that such an effect of accumulating sediment postulates a delicate balance1 a very thin crust and no resistance below4 ,if such a weakness were granted it would be impossible for the earth to hold up mountains4 ,furthermore such subsidence was not regular during its progress and finally in the long course of geologic time gave place to a reverse movement of elevation4 ,hall had pointed out the fact that the sediments were thickest on the east in the region of mountain folding and thinned out to a fraction of this thickness in the broad ,mississippi basin4 ,hall argued that the mere subsidence of the trough would produce the observed folding and that the folding was unrelated to mountain making or crustal shortening4 ,in supposed proof he cited the fact that the ,catskills consist of unfolded rock1 are higher than the folded region to the south1 and nearly as high as the highest metamorphic mountains to the east4#hg ,hall and all his contemporaries were handicapped in their geological theories by a complete inappreciation of the importance of subarial denudation4 ,for subscribing to these errors of their time even the ablest men should not be held responsible4 ,hall was the most forcible personality in geology in his generation4 ,his contributions to paleontology were superb4 ,his perception of the relation existing between troughs of thick sediments and folded structures was a contribution of the first importance2 yet in the structural field his argument as to the production of the ,appalachian folds by mere subsidence during deposition indicates a remarkable inability to apply the logical consequences of his hypothesis to the nature of the folds as already made known by the ,rogers4 ,dana pointed out in reply to ,hall that the folding did not correspond to the requirements of ,hall's hypothesis1 especially as the folding took place not during1 but after the close of the vast ,paleozoic deposition4 ,dana states in conclusion on ,hall's hypothesis 7#db1 #bji1 #ahff7 that 8,it is a theory of the origin of mountains with the origin of mountains left out40 ,the ,theory of ,geosynclines and ,geanticlines4 ,the fact that systems of folded strata lie along axes of especially thick sediments and that this implied subsidence during deposition was ,hall's contribution to geologic theory1 but curiously enough he failed1 as shown1 to connect it with the subsequent nature of mountain folding4 ,he did not see why such troughs should be weak to resist horizontal compression4 ,the clear recognition of this relationship was the contribution of ,le ,conte1 who in a paper on 8,a theory of the formation of the great features of the earth's surface0 7#d1 #cde1 #dfj1 #ahgb71 reached the conclusion that 8mountain chains are formed by the mashing together and the up-swelling of sea bottoms where immense thicknesses of sediment have accumulated40 ,as to the cause why mashing should take place along troughs of thick sediments ,le ,conte adopts the hypothesis of aqueo-igneous fusion proposed independently long before by ,babbage and ,herschel and elaborated into a theory of igneous rocks by ,hunt4 ,under this view1 as the older sediments became deeply buried1 the heat of the earth's interior ascended into them1 and since they included the water of sedimentation a softening and metamorphism resulted4 ,dana had shown1 however1 six years previously 7#db1 #beb1 #ahff71 as the following quotation will indicate1 that metamorphism of sediments required more than deep burial and that no such weakening as was postulated by ,herschel had occurred3 8,the correctness of ,herschel's principle cannot be doubted4 ,but the question of its actual agency in ordinary metamorphism must be decided by an appeal to facts2 and on this point ,i would here present a few facts for consideration4 ,the numbers and boldness of the flexures in the rocks of most metamorphic regions have always seemed to me to bear against the view that the heat causing the change had ascended by the very quiet method recognized in this theory4444 ,but there are other facts indicating a limited sufficiency to this means of metamorphism4 ,these are afforded by the great faults and sections of strata open to examination4 ,in the ,appalachian region1 both of ,virginia and ,pennsylvania1 faults occur1 as described by the ,professors ,rogers1 and by ,mr4 ,j4 ,p4 ,lesley1 which afford us important data for conclusions4 ,mr4 ,lesley1 an excellent geologist and geological observer1 who has explored personally the regions referred to1 states that at the great fault of ,juniata and ,blair ,cos41 ,pennsylvania1 the rocks of the ,trenton period are brought up to a level with those of the ,chemung1 making a dislocation of at least #af1jjj1 and probably of #bj1jjj1 feet4 ,and yet the ,trenton limestone and ,hudson ,river shales are not metamorphic4 ,some local cases of alteration occur there1 including patches of roofing slate2 but the greater part of the shales are no harder than the ordinary shales of the ,pennsylvania ,coal formation4 ,at a depth of #af1jjj feet the temperature of the earth's crust1 allowing an increase of #a ,f4 for #fj feet of descent1 would be about #ccj ,f42 or with #a ,f4 for #ej feet1 about #chj ,f4--either of which temperatures is far above the boiling point of water2 and with the thinner crust of ,paleozoic time the temperature at this depth should have been still higher4 ,but1 notwithstanding this heat1 and also the compression from so great an overlying mass1 the limestones and shales are not crystalline4 ,the change of parts of the shale to roofing slate is no evidence in favor of the efficiency of the alleged cause2 for such a cause should act uniformly over great areas40 ,the next contribution to the theory of orogeny was a series of papers published in #ahgc by ,dana1 entitled 8,on some results of the earth's contraction from cooling1 including a discussion on the origin of mountains and the nature of the earth's interior40#hh ,this contribution1 viewed as a whole1 ranks among the first half dozen papers on the science of mountains4 ,the following quoted paragraphs give a view of the scope of this article3 8,kinds and ,structure of ,mountains40 8,while mountains and mountain chains all over the world1 and low lands1 also1 have undergone uplifts1 in the course of their long history1 that are not explained on the idea that all mountain elevating is simply what may come from plication or crushing1 the component parts of mountain chains1 or those simple mountains or mountain ranges that are the product of one process of making--may have received1 at the time of their original making1 no elevation beyond that resulting from plication4 ,this leads us to a grand distinction in orography1 hitherto neglected1 which is fundamental and of the highest interest in dynamical geology2 a distinction between-- #a4 ,a simple or individual mountain mass or range1 which is the result of one process of making1 like an individual in any process of evolution1 and which may be distinguished as a monogenetic range1 being one in genesis2 and #b4 ,a composite or polygenetic range or chain1 made up of two or more monogenetic ranges combined4 ,the ,appalachian chain--the mountain region along the ,atlantic border of ,north ,america--is a polygenetic chain2 it consists1 like the ,rocky and other mountain chains1 of several monogenetic ranges1 the more important of which are3 #a4 ,the ,highland range 7including the ,blue ,ridge or parts of it1 and the ,adirondacks also1 if these belong to the same process of making7 pre-,silurian in formation2 #b4 ,the ,green ,mountain range1 in western ,new ,england and eastern ,new ,york1 completed essentially after the ,lower ,silurian era or during its closing period2 #c4 ,the ,alleghany range1 extending from southern ,new ,york southwestward to ,alabama1 and completed immediately after the ,carboniferous age4 ,the making of the ,alleghany range was carried forward at first through a long-continued subsidence--a geosynclinal 7not a true synclinal1 since the rocks of the bending crust may have had in them many true or simple synclinals as well as anticlinals71 and a consequent accumulation of sediments1 which occupied the whole of ,paleozoic time2 and it was completed1 finally1 in great breakings1 faultings and foldings or plications of the strata1 along with other results of disturbance4 ,these examples exhibit the characteristics of a large class of mountain masses or ranges4 ,a geosynclinal accompanied by sedimentary depositions1 and ending in a catastrophe of plications and solidification1 are the essential steps1 while metamorphism and igneous ejections are incidental results4 ,the process is one that produces final stability in the mass and its annexation generally to the more stable part of the continent1 though not stable against future oscillations of level of wider range1 nor against denudation4 ,it is apparent that in such a process of formation elevation by direct uplift of the underlying crust has no necessary place4 ,the attending plications may make elevations on a vast scale and so also may the shoves upward along the lines of fracture1 and crushing may sometimes add to the effect2 but elevation from an upward movement of the downward bent crust is only an incidental concomitant1 if it occur at all4 ,we perceive thus where the truth lies in ,professor ,le ,conte's important principle4 ,it should have in view alone monogenetic mountains and these only at the time of their making4 ,it will then read1 plication and shovings along fractures being made more prominent than crushing3 ,plication1 shoving along fractures and crushing are the true sources of the elevation that takes place during the making of geosynclinal monogenetic mountains4 ,and the statement of ,professor ,hall may be made right if we recognize the same distinction1 and1 also1 reverse the order and causal relation of the two events1 accumulation and subsidence2 and so make it read3 ,regions of monogenetic mountains were1 previous1 and preparatory1 to the making of the mountains1 areas each of a slowly progressing geosynclinal1 and1 consequently1 of thick accumulations of sediments4 ,the prominence and importance in orography of the mountain individualities described above as originating through a geosynclinal make it desirable that they should have a distinctive name2 and ,i therefore propose to call a mountain range of this kind a synclinorium1 from synclinal and the ,greek 1 mountain4 ,this brings us to another important distinction in orographic geology--that of a second kind of monogenetic mountain4 ,the synclinoria were made through a progressing geosynclinal4 ,those of the second kind1 here referred to1 were produced by a progressing geanticlinal4 ,they are simply the upward bendings in the oscillations of the earth's crust--the geanticlinal waves1 and hardly require a special name4 ,yet1 if one is desired1 the term anticlinorium1 the correlate of synclinorium1 would be appropriate4 ,many of them have disappeared in the course of the oscillations2 and yet1 some may have been for a time--perhaps millions of years--respectable mountains4 ,the geosynclinal ranges or synclinoria have experienced in almost all cases1 since their completion1 true elevation through great geanticlinal movements1 but movements that embraced a wider range of crust than that concerned in the preceding geosynclinal movements1 indeed a range of crust that comes strictly under the designation of a polygenetic mass40 8,the ,condition of the ,earth's ,interior40 8,the condition of the earth's interior is not among the geological results of contraction from cooling4 ,but these results offer an argument of great weight respecting the earth's interior condition1 and make it desirable that the subject should be discussed in this connection4 ,moreover1 the facts throw additional light on the preceding topic--the origin of mountains4 ,it seems now to be demonstrated by astronomical and physical arguments--arguments that are independent1 it should be noted1 of direct geological observation--that the interior of our globe is essentially solid4 ,but the great oscillations of the earth's surface1 which have seemed to demand for explanation a liquid interior1 still remain facts1 and present apparently a greater difficulty than ever to the geologist4 ,professor ,le ,conte's views1 in volume iv1 were offered by him as a method of meeting this difficulty2 yet1 as he admits in his concluding remarks1 the oscillations over the interior of a continent1 and the fact of the greater movements on the borders of the larger ocean1 were left by him unexplained4 ,yet these oscillations are not more real than the changes of level or greater oscillations which occurred along the sea border1 where mountains were the final result2 and this being a demonstrated truth1 no less than the general solidity of the earth's interior1 the question comes up1 how are the two truths compatible8 ,the geological argument on the subject 7the only one within our present purpose7 has often been presented4 ,but it derives new force and gives clearer revelations when the facts are viewed in the light of the principles that have been explained in the preceding part of this memoir4 ,the ,appalachian subsidence in the ,alleghany region of #ce1jjj to #dj1jjj feet1 going on through all the ,paleozoic era1 was due1 as has been shown1 to an actual sinking of the earth's crust through lateral pressure1 and not to local contraction in the strata themselves or the terranes underneath4 ,but such a subsidence is not possible1 unless seven miles--that is1 seven miles in maximum depth and over a hundred in total breadth--unless seven miles of something were removed1 in its progress1 from the region beneath4 ,if the matter beneath was not arial1 then liquid or viscous rock was pushed aside4 ,this being a fact1 it would follow that there existed1 underneath a crust of unascertained thickness1 a sea or lake of mobile 7viscous or plastic7 rock1 as large as the sinking region2 and also that this great viscous sea continued in existence through the whole period of subsidence1 or1 in the case of the ,alleghany region1 through all ,paleozoic time--an era estimated on a previous page to cover at least thirty-five millions of years1 if time since the ,silurian age began embraced fifty millions of years4 ,the facts thus sustain the statement that lateral pressure produced not only the subsidence of the ,appalachian region through the ,paleozoic1 but also1 cotemporaneously1 and as its essential prerequisite1 the rising of a sea-border elevation1 or geanticlinal1 parallel with it2 and that both movements demanded the existence beneath of a great sea of mobile rock40 ,the recognition of regional warping as a major factor in the larger structure of mountain systems1 and the expression of that factor in the terms geosyncline and geanticline forms a notable advance in geologic thought4 ,subsequent folding on a regional scale results in the development of synclinoria and anticlinoria4 ,van ,hise has given these latter terms wide currency1 but apparently inadvertently has used synclinorium in a different sense than that in which ,dana defined it4 ,dana gave the word to a mountain range made by the mashing and uplift of a geosyncline1 ,van ,hise defines it as a downfold of a large order of magnitude1 embracing anticlines and synclines within it2 anticlinorium he uses for a corresponding up fold4#hi ,rice has called attention to this change of definition1#ij but ,van ,hise's usage is likely to prevail1 since they are needed terms for the larger mountain structure and do not require a determination of the previous limits of upwarp and downwarp1--of original denudation and deposition4 ,furthermore1 a geosyncline in mountain folding may have one side uplifted1 the other side depressed and there are reasons for regarding the folds of ,pennsylvania1 ,dana's type synclinorium1 as representing but the western and downfolded side of the ,paleozoic geosyncline4 ,under that view the folded ,appalachians of ,pennsylvania constitute a synclinorium in both the sense of ,dana and ,van ,hise4 ,the ,ultimate ,cause of ,crustal ,compression4 ,the next important advance in the theory of mountains was made by ,c4 ,e4 ,dutton who in #ahgd published in the ,journal 7#h1 #aac-abc7 an article entitled 8,a criticism upon the contractional hypothesis40 ,dutton gives reasons for holding that the amount of folding and shortening exhibited in mountain ranges1 especially those of ,tertiary date1 is very much greater in magnitude and is different in nature and distribution from that which would be given by the surficial cooling of the globe4 ,the following quotations cover the principal points in the argument3 8,the argument for the contractional hypothesis presupposes that the earth-mass may be considered as consisting of two portions1 a cooled exterior of undetermined 7though probably comparatively small7 depth1 inclosing a hot nucleus4444 ,the secular loss of heat1 it is assumed1 would be greater from the hot nucleus than from the exterior1 and the greater consequent contraction of the nucleus would therefore gradually withdraw the support of the exterior1 which would collapse4 ,the resulting strains upon the exterior would be mainly tangential4 ,owing to considerable inequalities in the ability of different portions to resist the strains thus developed1 the yielding would take place at the lines1 or regions of least resistance1 and the effects of the yielding would be manifested chiefly1 or wholly1 at those places1 in the form of mountain chains1 or belts of table lands1 and in the disturbances of stratification4 ,the primary division of the surface into areas of land and water are attributed to the assumed smaller conductivity of materials underlying the land1 which have been left behind in the general convergence of the surface toward the center4 ,regarding these as the main and underlying premises of the contractional argument1 it is considered unnecessary to state the various subsidiary propositions which have been advanced to explain the determination of this action to particular phenomena1 since the main proposition upon which they are based is considered untenable4 ,there can be no reasonable doubt that the earth-mass consists of a cooled exterior inclosing a hot nucleus1 and a necessary corollary to this must be secular cooling1 probably accompanied by contraction of the cooling portions4 ,but when we apply the known laws of thermal physics to ascertain the rate of this cooling1 and its distribution through the mass1 the objectionable character of the contractional hypothesis becomes obvious4 ,that ,fourier's theorem1 under the general conditions given1 expresses the normal law of cooling1 is admitted by all mathematicians who have examined it4 ,the only ground of controversy must be upon the values to be assigned to the constants4 ,but there seem to be no values consistent with probability which can be of help to the contractional hypothesis4 ,the application of the theorem shows that below #bjj or #cjj miles the cooling has1 up to the present time1 been extremely little4444 ,at present1 however1 the unavoidable deduction from this theorem is that the greatest possible contraction due to secular cooling is insufficient in amount to account for the phenomena attributed to it by the contractional hypothesis4 ,the determination of plications to particular localities presents difficulties in the way of the contractional hypothesis which have been underrated4 ,it has been assumed that if a contraction of the interior were to occur1 the yielding of the outer crust would take place at localities of least resistance4 ,but this could be true only on the assumption that the crust could have a horizontal movement in which the nucleus does not necessarily share4 ,a vertical section through the ,appalachian region and westward to the #ajjth meridian shows a surface highly disturbed for about two hundred and fifty miles1 and comparatively undisturbed for more than a thousand4 ,no one would seriously argue that the contraction of the nucleus had been confined to portions underlying the disturbed regions3 yet if the contraction was general1 there must have been a large amount of slip of some portion of the undisturbed segment over the nucleus4 ,such a proposition would be very difficult to defend1 even if the premises were granted4 ,it seems as if the friction and adhesion of the crust upon the nucleus had been overlooked4 ,nor could this be small1 even though the crust rested upon liquid lava4 ,the attempts which some eminent geologists have recently made to explain surface corrugation by this method clearly show a neglect on their part to analyze carefully the system of forces which a contraction of the nucleus would generate in the crust4 ,their discussions have been argumentative and not analytical4 ,the latter method of examination would have shown them certain difficulties irreconcilable with their knowledge of facts4 ,adopting the argumentative mode1 and in conformity with their view regarding the exterior as a shell of insufficient coherence to sustain itself when its support is sensibly diminished1 the tendency of corrugation to occur mainly along certain belts1 with series of parallel folds1 is not explained by assuming that these localities are regions of weakness4 ,for a shrinkage of the nucleus would throw each elementary portion of the crust into a state of strain by the action of forces in all directions within its own tangent plane4 ,a relief by a horizontal yielding in one direction would by no means be a general relief40 ,dutton's criticisms robbed the current hypothesis of mountain-making of its conventional basis without providing a new foundation4 ,it was a quarter of a century in advance of its time1 has been seldom cited1 and seems to have had but little direct influence in shaping subsequent thought4 ,it1 however1 gave direction to ,dutton's views1 and his later papers were far-reaching in their influence4 ,if contraction from external cooling is not the cause of the compressive forces it is necessary to seek another cause4 ,two years later1 in #ahgf1 ,dutton attempted to provide an answer to this open question4#ia ,a review of this paper1 evidently by ,j4 ,d4 ,dana1 is given in the ,journal4 ,the following explanations of ,dutton's theory and of ,dana's comments upon it are contained in a few paragraphs from this review 7#ab1 #adb1 #ahgf74 8,captain ,dutton presents in this paper the views brought out in his article in volume viii of this ,journal1 with fuller illustrations1 and adds explanations of his theory of the origin of mountains4 ,the discussion should be read by all desiring to reach right conclusions1 it presenting many arguments from physical considerations against the contraction-theory1 or that of the uplifting and folding of strata through lateral pressure4 ,there is much to be learned before any theory of mountain-making shall have a sufficient foundation in observed facts to demand full confidence1 and ,captain ,dutton merits the thanks of geologists for the aid he has given them toward reaching right conclusions4 ,his discussions are not free from misunderstandings of geological facts1 and if they fail to be finally received it will be for this reason4 ,we here give in a brief form1 and nearly in his own words1 the principal points in his theory of mountain-making as explained in the later part of his memoir4 ,accepting the proposition that there is a plastic condition of rock beneath the earth's crust and that metamorphism is a #8hydrothermal process1' and believing that #8the penetration of water to profound depths in the earth's crust is a well sustained theory1' he says that great pressure and a temperature approaching redness are essential conditions of metamorphism4444 #8,the heaviest portion would sink into the lighter colloid mass underneath1 protruding it laterally beneath the lighter portions where1 by its lighter density1 it tends to accumulate4' ,he adds3 #8,the resulting movements would be determined1 first1 by the amount of difference in the densities of the upper and lower masses1 and1 second1 by inequalities in the thickness of the strata3 the forces now become adequate to the building of mountains and the plication of strata1 and their modes of operation agree with the classes of facts already set forth as the concomitants of those features4' ,the views are next applied to a system of plications4 #8,it has been indicated that plications occur where strata have rapidly accumulated in great volume and in elongated narrow belts2 that the axes of plications are parallel to the axes of maximum deposit2 and that the movements immediately followed the deposition'--the case of the ,appalachians being an example in which the accumulations averaged #dj1jjj feet4 ,he observes3 #8,wherever the load of sediments becomes heaviest1 there they sink deepest1 protruding the colloid magma beneath them to the adjoining areas1 which are less heavily weighted1 forming at once both synclinals and anticlinals4' ,with regard to this new theory1 we might reasonably question the existence of the colloid magma--a condition fundamental to the theory--and his evidence that water penetrates to profound depths in the earth's crust sufficient to make hydrous rocks4 ,we might ask for evidence that the rocks beneath the ,cretaceous and ,tertiary1 and other underlying strata of the ,uintahs1 were in such a colloid state1 and this so near the surface1 that the #8beds subsided by their gross weight as rapidly as they grew4' ,again1 he says that the movements of mountain-making #8immediately followed the deposition4' #8,immediately' sounds quick to one who appreciates the slowness of geological changes4 ,the ,carboniferous age was very long2 and somewhere in that part of geological time1 either before the age had fully ended1 or some time after its close1 the epoch of catastrophe began40 ,we see foreshadowed in this paper the theory of isostasy1 or condition of vertical equilibrium in the crust which ,dutton published in #ahhi4 ,this theory has borne remarkable fruit1 but ,dutton attempted to link to it the horizontally compressive forces which have produced folding and overthrusting4 ,willis in #aijgib and ,hayford in #aiaa1 overlooking ,dana's objections1 have attempted to make a lateral isostatic undertow the cause of all horizontal movements in the crust1 adopting the mechanism of ,dutton4 ,the present writer1 although accepting the principle of isostasy as an explanation of broad vertical movements1 has published papers which go to show the inadequacy of this hypothesis of lateral pressure2 inadequate in time relation1 in amount1 and in expression4#ic ,in #aijc it was determined by several physicists that the materials of the earth's crust were radioactive and must generate throughout geologic time a quantity of heat which perhaps equalled that lost by radiation into space4 ,by #aijg this had become demonstrated4 ,the remarkable conclusion had been reached that the earth1 although losing heat1 is not a cooling globe4 ,dutton's contentions against mountain growth through external cooling and contraction were thus unexpectedly1 through a wholly new branch of knowledge1 demonstrated to be true4 ,nevertheless1 all students of orogeny are agreed that profound compressive forces have been the chief agents in developing mountain structures4 ,chamberlin was the first to arrive at the idea that the shrinkage may originate in the deeper portions of the earth under the urgency of the enormous pressures1 apparently by giving rise to slow recombinations of matter into denser forms4#id ,the ,new ,era in the ,interpretation of ,mountain ,structures4 ,in the meantime1 between #ahgd and #aijd1 another advance in the knowledge of mountain structures was taking place in ,europe4 ,suess studied the distribution of mountain arcs over the earth and dwelt upon the prevalence of overthrust structures2 the backland being thrust toward and over the foreland1 the rise of the mountain arc or geanticline depressing the foredeep or geosyncline4 ,bertrand and ,lugeon from #ahhd to #aijj were reinterpreting the ,alpine structures on this basis4 ,they showed that the whole mountain system had been overturned and overthrust from the south to an almost incredible degree4 ,enormous denudation had later dissevered the northern outlying portions and given rise to 8mountains without roots10--isolated outliers1 consisting of overturned masses of strata which had accumulated as sediments far to the southward in another portion of the ancient geosyncline4 ,on a smaller scale similar phenomena are exhibited in the ,appalachians4 ,willis showed that the deep subsidence of the center of the geosyncline gave an initial dip which determined the position of yielding under compression4 ,laboratory experiments brought out the weakness of the stratigraphic structure to resist horizontal compression4 ,the nature of the stratigraphic series was shown to determine whether the yielding would be by mashing1 competent folding1 or breakage and overthrust4 ,the problem of mountain structures was thus brought into the realm of mechanics4 ,these results were published in three sources in #ahic1--the ,transactions of the ,american ,institute of ,mining ,engineers1 the thirteenth annual report of the ,united ,states ,geological ,survey1 and the ,journal 7#df1 #beg1 #ahic74 ,finally should be noted the contributions of the ,lake ,superior school of geology1 in which the work of ,van ,hise stands preeminent4 ,under the economic stimulus given by the discovery and development of enormously rich bodies of iron ore1 hidden under ,pleistocene drift and involved in the complex structures of vanished mountain systems of ancient date1 structural geology and metamorphism have become exact sciences to be drawn upon in the search for mineral wealth and yielding also rich returns in a fuller knowledge of early periods of earth history4 ,crust ,movements as ,revealed by ,physiography4 ,during the last quarter of the nineteenth century another division of geology1 dominantly ,american1 was taking form and growth1--the science of land forms1--physiography4 ,the history of that development is treated by ,gregory in the preceding chapter but some of its bearings upon theory1 in so far as they affect the subject of mountain origin1 are necessarily given here4 ,powell1 ,dutton1 and ,gilbert in their explorations of the ,west saw the stupendous work of denudation which had been carried to completion again and again during the progress of geologic time4 ,the mountain relief consequently may be much younger than the folding of the rocks1 and may be largely or even wholly due to recurrent plateau movement1 a doctrine to which ,dana had previously arrived4 ,but the introduction of the idea of the peneplain opened up a new field for exploration in the nature and date of crust movements4 ,davis by this means began to study the later chapters of ,appalachian history1 the most important early paper being published in #ahia4ie ,since then ,davis1 ,willis1 and many others have found that1 girdling the world1 a large part of the mountainous relief is due to vertical elevatory forces acting over regions of previous folding and overthrust4 ,in addition1 great plateau areas of unfolded rocks have been bodily lifted one to two miles1 or more1 above their earlier levels4 ,they may be broad geanticlinal arches or bounded by the walls of profound fractures4 ,the linear mountain systems made from deep troughs of sediments have come then to be recognized as but one of several classes of mountains4 ,this class1 from its clear development in the ,appalachians1 and the fact that many of the laws of mountain structure pertaining to it were first worked out there1 has been called by ,powell the ,appalachian type 7#ab1 #dad1 #ahgf74 ,a classification of mountain systems was proposed by him in which mountains are classified into two major divisions1 those composed of sedimentary strata altered or unaltered1 and those composed in whole or in part of extravasated material4 ,the first class he subdivides into six sub-classes of which the folded ,appalachians illustrate one4 ,it appears to the writer that ,powell's classification gives disproportionate importance to certain types which he described2 but nevertheless1 the fact that such a classification was made1 indicates the growth of a more comprehensive knowledge of mountains1--their origin1 structure1 and history4 ,relations of ,crust ,movements to ,density and ,equilibrium4 ,a recent important development in the fields of geophysics and major crust movements consists in the incorporation into geology of the doctrine of isostasy4 ,the evidence was developed in the middle of the nineteenth century by the geodetic survey of ,india which indicated that the ,himalayas did not exert the gravitative influence that their volume called for4 ,it was clear that the crust beneath that mountain system was less dense than beneath the plains of ,india and still less dense than the crust beneath the ,indian ,ocean4 ,this relation between density and elevation indicated some approach to flotational equilibrium in the crust1 comparable in its nature though not in delicacy of adjustment to the elevation of the surface of an iceberg above the ocean level owing to its depth and its density1 less than that of the surrounding medium4 ,this important geological conception was kept within the confines of astronomy and geodesy1 however1 until ,dutton in #ahgf1 but especially in #ahhi1 brought it into the geologic field4 ,a test of isostasy was made for the ,united ,states by ,putnam and ,gilbert in #ahie and much more elaborate investigations have since been made by ,hayford and ,bowie4 ,these investigations demonstrate the importance and reality of broad warping forces acting vertically and related to the regional variations of density in the crust4 ,there are consequently two major and unrelated classes of forces involved in the making of mountain structures1--the irresistible horizontal compressive forces1 arising apparently from condensation deep within the earth1 and vertical forces originating in the outer envelopes and tending toward a hydrostatic equilibrium4 ,in this latter field of investigation1 ,america1 since the initial paper by ,dutton1 has taken the lead4 ,conclusion on ,contributions of ,america to ,theories of ,orogeny4 ,the sciences arose in ,europe1 but those which treated of the earth were still in their infancy when transplanted to ,america4 ,the first comprehensive ideas on the nature of mountain structures arose in ,great ,britain and ,france4 ,these ideas served as a guide and stimulus to observation in the recognition of deformations in the strata of the ,appalachian system4 ,since #ahdj1 however1 ,america has ceased to be a pupil in this field of research but has joined as an equal with the two older countries4 ,new ideas have been contributed1 new and striking illustrations cited1 first by the scientists of one nation1 next by those of another4 ,the composite mass of knowledge has grown as a common possession4 ,nevertheless1 a review of the progress since #ahdj as measured by the contribution of new ideas shows on the whole ,america at least equal to its intellectual rivals1 and at certain times actually the leader4 ,this is true of the science of geology as a whole and also of the subdivision of orogeny4 ,thus far no mention has been made of ,german geologists1 with the exception of ,suess1 an ,austrian4 ,german geology is voluminous and the names of many well-known geologists could be cited4 ,but this article has sought to trace the origin and growth of fundamental ideas4 ,the ,germans have been assiduous observers of detail2 preeminent as systematizers and classifiers1 seldom originators4 ,even petrology1 which might be regarded as their especial field1 was transplanted from ,great ,britain4 ,in the science of mountains they have followed in their fundamental ideas especially the ,french4 ,turning to the mediums of publication through which this progress of knowledge in earth structures has been recorded1 the ,american ,journal of ,science stands foremost as the only continuous record for the whole century in ,american literature1 fulfilling for this country what the ,quarterly ,journal of the ,geological ,society has done for ,great ,britain since #ahde1 and the ,bulletin de la ,socit ,gologique for ,france since #ahcj4 ,notes4 ,footnote #gh3 ,h4 ,d4 ,rogers1 ,geology of ,new ,jersey1 ,final ,report1 p4 #aae1 #ahdj4 ,footnote #gi3 ,h4 ,d4 ,rogers1 ,geology of ,pennsylvania1 vol4 #b1 pt4 ,,ii1 pp4 #gfa1 #gfb1 #aheh4 ,footnote #hj3 ,connecticut ,academy of ,arts and ,sciences1 #ahaj2 quoted by ,g4 ,p4 ,merrill in ,contributions to the ,history of ,north ,american geology1 ,ann4 ,rpt4 ,smithsonian ,institution for #aijd1 p4 #baf4 ,footnote #ha3 ,a ,sketch of the geology1 mineralogy1 and scenery of the regions contiguous to the river ,connecticut2 with a geological map and drawings of organic remains2 and occasional botanical notices1 the ,journal1 #f1 #a-hf1 #bja-bcf1 #ahbc2 #g1 #a-cj1 #ahbd4 ,footnote #hb3 ,clarence ,king1 ,u4 ,s4 ,geol4 ,exploration of the ,fortieth ,parallel1 vol4 #a1 pp4 #af1 #dd-dh1 #ahgh4 ,footnote #hc3 ,illustrations of the ,huttonian ,theory of the ,earth1 pp4 #bai-bch1 #ahjb4 ,footnote #hd3 ,robert ,jameson1 ,elements of ,geognosy1 pp4 #ee-eg1 #ahjh4 ,footnote #he3 ,g4 ,p4 ,merrill1 ,contributions to the ,history of ,american ,geology4 ,report of the ,u4 ,s4 ,national ,museum for #aijd1 p4 #cbh4 ,footnote #hf3 ,h4 ,d4 ,rogers1 ,geology of ,pennsylvania1 vol4 #b1 p4 #iaf1 #aheh4 ,footnote #hg3 ,james ,hall1 ,natural ,history of ,new ,york1 ,paleontology1 vol4 #c1 pp4 #ea-gc1 #ahei4 ,footnote #hh3 ,the ,journal1 #e1 #dbc-ddc1 #dgd1 #dge2 #f1 #f-ad1 #ajd-aae1 #afa-agb1 #cjd1 #cha1 #chb1 #ahgc4 ,footnote #hi3 ,c4 ,r4 ,van ,hise1 ,principles of ,north ,american ,pre-,cambrian ,geology1 ,u4 ,s4 ,geol4 ,surv41 #afth ,ann4 ,report1 pt4 ,i1 pp4 #fjg-fab1 #ahif4 ,footnote #ij3 ,w4 ,n4 ,rice1 ,on the use of the words synclinorium and anticlinorium1 ,science1 #bc1 #bhf1 #bhg1 #aijf4 ,footnote #ia3 ,c4 ,e4 ,dutton1 ,critical observations on theories of the earth's physical evolution1 ,the ,penn ,monthly1 ,may and ,june1 #ahgf4 ,footnote #ib3 ,b4 ,willis1 ,research in ,china1 vol4 #b1 #aijg4 ,footnote #ic3 ,joseph ,barrell1 ,science1 #ci1 #bei1 #bfj1 #aiji2 ,jour4 ,geol41 #bb1 #fgb-fhc1 #aiad4 ,footnote #id3 ,t4 ,c4 ,chamberlin1 ,geology1 vol4 #a1 pp4 #eda1 #edb1 #aijd4 ,footnote #ie3 ,w4 ,m4 ,davis1 ,the geological dates of origin of certain topographic forms on the ,atlantic slope of the ,united ,states1 ,geol4 ,soc4 ,am4 ,bull41 #b1 #eda-edb1 #ede-ehf1 #ahia4 ,v ,a ,,century ,,of ,,government ,,geological ,,surveys ,by ,,george ,,otis ,,smith ,director of the ,united ,states ,geological ,survey ,even a ,federal ,bureau must be considered a product of evolution3 the past of the ,united ,states ,geological ,survey far antedates ,march #c1 #ahgi4 ,the scope of endeavor1 the refinement of method1 and especially the personnel of the newly created service of that day were largely inherited from pioneer organizations4 ,therefore a review of the country's record of surveys under ,government auspices becomes more than a grateful acknowledgment by the present generation of geologists of the credit due to those who blazed the way2 it shows the sequence and progress in the contributions made by geologic science to industry4 ,the earlier stages in industrial evolution mentioned by ,hess#if--;exploitation1 development1 and maturity--determine a somewhat similar progressive development in geologic investigation1 so that geographic exploration and geologic reconnaissance of the broadest type are the normal contribution of exact science whenever and wherever a nation is in the state of exploitation and initial development of its mineral and agricultural resources4 ,the refinements of detailed surveys and quantitative examinations belong rather to the next stage of intensive utilization1 or1 indeed1 they are the essentials preliminary to full use4 ,thus regrets that the results of present-day work were not available fifty years ago are largely vain3 the fathers may not have been without the vision2 they simply did the work as their day and generation needed it done4 ,twenty years ago ,s4 ,f4 ,emmons1 in a presidential address before the ,geological ,society of ,washington1 divided the history of ,governmental surveys in this country into two periods1 separated in a general way by the ,civil ,war4 ,the first of these was the period of geographic exploration1 the second that of geologic exploration4 ,mr4 ,emmons of course regarded this subdivision as not hard and fast1 yet his dividing line seems logical1 for not only did the military activities in the ,east necessarily suspend exploration in the ,west1 but after the war national1 political1 and economic considerations led naturally to the demand for a more exact knowledge of the vast national domain in the ,west4 ,geography and geology are so closely related that ,mr4 ,emmons's distinction of the two periods is useful only with the limitations inferentially set by himself--namely1 that while geologic investigation entered into most of the explorations of the earlier period1 the geologist was regarded as only an accessory in these exploring expeditions2 on the other hand1 in the later surveys the topographic work was developed because it was essential to the geologic investigations4 ,the year #ahah was a notable one in ,american geology1 first of all in the appearance of the ,american ,journal of ,science1 itself so perfect a vehicle for geological thought that1 as is so well stated by ,dr4 ,g4 ,p4 ,merrill1 8a perusal of the numbers from the date of issue down to the present time will alone afford a fair idea of the gradual progress of ,american geology40 ,the beginning of publications on ,new ,england geology appeared that year in ,edward ,hitchcock's first paper on the ,connecticut ,valley 7#a1 #aje1 #ahah7 and the ,danas' 7,s4 ,l4 and ,j4 ,f47 detailed geologic and mineralogic description of ,boston and vicinity2 and the 8,index0 of ,amos ,eaton 7noticed in this ,journal1 #a1 #fi7 was the first of that long list of notable contributions to ,american stratigraphy that are to be credited to the ,new ,york geologists4 ,in the present discussion1 too1 the year #aiah can be regarded as in a way the centennial of ,government geologic surveys1 for it was in #ahah that ,henry ,r4 ,schoolcraft began his trip to the ,mississippi ,valley--perhaps the first geologic reconnaissance into the ,west--and it was his work in the lead region which served to make him a member of the ,cass expedition sent out by the ,secretary of ,war in #ahbj to examine the metallic wealth of the ,lake ,superior region4 ,the earlier ,government explorations of ,lewis and ,clark1 in #ahjc-g1 and of ,pike1 in #ahje-g1 were so exclusively geographic that geologic work under ,federal auspices must be regarded as beginning with ,schoolcraft and with ,edwin ,james1 the geologist of the expedition of ,major ,long in #ahai-bj to the ,rocky ,mountains4 ,both these observers published reports that are valuable as contributions to the knowledge of littleknown regions4 ,any description of geologic work under the ,federal ,government that included no reference to the ,state surveys would be inadequate1 for in both date of execution and stage of development the work of the ,state geologists must be given precedence4 ,in ,merrill's ,contributions to the ,history of ,american ,geology1#ig whose modest title fails even to suggest that this work not only furnishes the most useful chronologic record of the progress of the science on the ,american continent but is in fact a very thesaurus of incidents touching the personal side of geology1 the author by his division of his subject shows that four decades of the era of ,state surveys elapsed before the era of national surveys began4 ,thus the geologic surveys of some of the ,eastern ,states antedate by several decades any ,federal organization of comparable geologic scope1 and in investigations directed to local utilitarian problems these pioneer geologists working in the older settled ,states of the ,east were in fact already conducting work as detailed in type as much of that attempted by the ,federal geologists of the later period4 ,even to-day it is true in a general way that the ,state geologist can and should attack many of his local problems with intensive methods and with detail of results that are neither practicable nor desirable for the larger interstate investigations or for examinations in newer territory4 ,all this relation of ,state and ,federal work must be looked upon as normal evolutionary development of geologic science in ,america4 ,one who reads the names of the ,federal geologists of the early days1 beginning with ,jackson and ,owen and following with such leaders in ,federal work as ,gilbert1 ,chamberlin1 ,king1 ,r4 ,d4 ,irving1 ,pumpelly1 ,van ,hise1 and ,walcott1 may note that these were all connected in their earlier work with ,state surveys4 ,nor has the relation been one-sided1 for among the ,state geologists ,whitney1 ,blake1 ,mather1 ,newberry1 ,j4 ,g4 ,norwood1 ,purdue1 ,bain1 ,gregory1 ,ashley1 ,kirk1 ,w4 ,h4 ,emmons1 ,de,wolf1 ,mathews1 ,brown1 ,landes1 ,moore1 and ,crider received their field training in part or wholly as members of a ,federal ,survey4 ,moreover1 under the present plan of effective cooperation of several of the ,state surveys with the ,united ,states ,geological ,survey1 it is often difficult to differentiate between the two in either personnel or results1 for it even happens that the publishing organization may not have been the major contributor4 ,the full record of ,american geology1 past and present1 can not be set forth in terms of ,federal auspices alone4 ,the three decades preceding the ,civil ,war1 then1 constitute the era of ,state surveys1 well described by ,merrill as at first characterized by a contagious enthusiasm for beginning geologic work1 later by a more normal condition in which every available geologist seems to have been quietly at work1 and finally by renewed activity in creating new organizations4 ,the net result was that ,louisiana and ,oregon seem to have been the only ,states not having at least one geological survey4 ,illustration3 ,from 8,contributions to the ,history of ,american ,geology0 by ,george ,p4 ,merrills4 ,the first specific appropriation by the ,federal ,government for geologic investigation appears to have been made in #ahcd1 when a supplemental appropriation for surveys of roads and canals under the ,war ,department1 authorized in #ahbd1 contained the item 8of which sum five thousand dollars shall be appropriated and applied to geological and mineralogical survey and researches40 ,in ,july1 #ahcd1 ,mr4 ,g4 ,w4 ,featherstonhaugh was appointed ,united ,states geologist and employed under ,colonel ,abert1 ,u4 ,s4 ,topographical ,engineers1 to 8personally inspect the mineral and geological character0 of the public lands of the ,ozark ,mountain region4 ,overlooking the incidental fact that this ,englishman--a man of scientific attainment and large interest in public affairs--was never naturalized1#ih it must be placed to the credit of this first of ,united ,states geologists that within seven months he completed his field work and returned to ,washington1 and on ,february #ag1 #ahce1 his report was transmitted to ,congress4 ,two years earlier ,featherstonhaugh had memorialized ,congress for aid in the preparation of a geologic map of the whole territory of the ,united ,states1 and in connection with this project he suggested that geology as an aid to military engineering should have a place in the curriculum at ,west ,point4 ,this first ,united ,states geologist also appears to have combined an appreciation of the practical worth of 8the mineral riches of our country1 their quality1 quantity1 and the facility of procuring them10 with an interest in the more scientific side of geology1 though his hypotheses regarding both economic geology and stratigraphic and structural geology have not won the endorsement of all later workers in the same regions4 ,in all these respects1 however1 ,featherstonhaugh may stand as a fairly good prototype4 ,his contributions to international affairs subsequent to his scientific service to the ,united ,states are of interest2 he served as one of ,her ,majesty's commissioners in the settlement of the ,canadian-,united ,states boundary question in #ahci-dj and made an examination of the disputed area1 and after the settlement of this controversy he was appointed ,british ,consul for the ,department of the ,seine1 ,france1 where in #ahdh he personally engineered the escape of ,louis ,philippe from ,havre4 ,the ,federal geologic work thus started was soon continued in surveys of wider scope and more thorough accomplishment4 ,the position of the ,government as the proprietor of mineral lands in the ,upper ,mississippi ,valley led to their examination4 ,these ,government lands containing lead had been reserved from sale for lease since #ahjg1 although no leases were issued until #ahbb4 ,the amount of illegal entry and consequent refusal of smelters and miners to pay royalty after #ahcd forced the issue upon the attention of ,congress1 and in #ahci ,president ,van ,buren was requested to present to ,congress a plan for the sale of the public mineral lands4 ,in carrying out this policy ,dr4 ,david ,dale ,owen was selected to make the necessary survey4 ,owen had served as an assistant on the ,state ,survey of ,tennessee and as the first ,state geologist of ,indiana1 and he organized the new work promptly and effectively4 ,although suffering from the handicap unfortunately known by geologists of the present day--the receipt late in the season 7,august #ag1 #ahci7 of authority to begin work--within exactly a month he had his force of #aci assistants organized into #bd field parties1 instructed in 8such elementary principles of geology as were necessary to their performance of the duties required of them40 ,his plan of campaign provided for a northward drive at a predetermined rate of traverse for each party1 with periodic reports to himself at appointed stations1 8to receive which reports and to examine the country in person0 he crossed the area under survey eleven times4 ,the result of such masterful leadership was the completion of the exploration of all the lands comprehended in his orders in two months and six days1 and his report on this great area--about #aa1jjj square miles--bears date of ,april #b1 #ahdj4 ,eight years later ,doctor ,owen made a survey of an even larger area1 continuing his examination northward to ,lake ,superior4 ,again his report was published promptly1 and he continued for several years his examination of the ,northwest ,territory1 submitting his final report in #ahea4 ,it is interesting to note that in his earlier report ,doctor ,owen subscribed himself as 8,principal ,agent to explore the ,mineral ,lands of the ,united ,states10 but that in the later report he was 8,u4 ,s4 ,geologist for ,wisconsin40 ,the two surveys together covered #eg1jjj square miles4 ,during the same period similar surveys were being made in northern ,michigan by ,dr4 ,charles ,t4 ,jackson1 #ahdg-dh1 and ,foster and ,whitney1 #ahdi-ea4 ,these surveys also had been hastened by the 8copper fever0 of #ahdd-df1 with wholesale issue of permits and leases1 ,congress in #ahdg authorizing the sale of the mineral lands and a geological survey of the ,lake ,superior district4 ,the execution of these surveys under ,jackson and under ,foster and ,whitney and the prompt publication in #ahea of the maps of the whole region materially helped to establish copper mining on a more conservative basis4 and the development of the ,lake ,superior region was rapid4#ii ,these land-classification surveys1 with their definite purpose1 represent the best geologic work of the time4 ,the plan necessitated thoroughgoing field work with considerable detail and prompt publication of systematic reports1 and in the working up of the results specialists like ,james ,hall and ,joseph ,leidy contributed1 while ,f4 ,b4 ,meek was an assistant of ,owen4 ,it is worthy of note that had not ,doctor ,houghton1 the ,state geologist of ,michigan1 met an untimely death in #ahdg1 effective cooperation of the ,state ,survey with the ,federal officials would have combined geologic investigation with the execution of the linear surveys4#ajj ,belonging to the same period of geologic exploration was the service of ,j4 ,d4 ,dana1 as ,united ,states ,geologist on the ,wilkes ,exploring ,expedition1 the disaster to which compelled his return from the ,pacific ,coast overland and resulted in his geologic observations on ,oregon and northern ,california4 ,the military expeditions during the decade #ahej-fj and the earlier expeditions of ,fremont added to the geographic knowledge of the ,western country and also contributed to geologic science1 largely through collections of rocks and fossils1 usually reported on by the specialists of the day4 ,thus the names of ,hall1 ,conrad1 ,hitchcock1 and ,meek appear in the published reports on these explorations1 while ,marcou1 ,blake1 ,newberry1 ,gibbs1 ,evans1 ,hayden1 ,parry1 ,shumard1 ,schiel1 ,antisell1 and ,engelmann were geologists attached to the field expeditions4 ,in #aheb geologic investigation was seemingly so popular as to necessitate the statutory prohibition 8there shall be no further geological survey by the ,government unless hereafter authorized by law40 ,certain of these explorations had a specific purpose3 several of them sought a practical route for a transcontinental railroad2 another a new wagon road across ,utah and ,nevada2 and one under ,colonel ,pope1 with ,g4 ,g4 ,shumard as geologist1 was sent out 8for boring ,artesian ,wells along the line of the #cb;d ,parallel0 in ,new ,mexico4 ,the published reports varied greatly in scientific value and in carefulness of preparation1 while the publication of at least two reports was delayed until long after the war1 and the manuscript of another was lost4 ,the report of the expedition of ,major ,emory contained a colored geologic map of the western half of the country1 a pioneer publication1 for the map prepared by ,marcou extended only to the #ajfth meridian4 ,thus in the first period of ,government surveys1 covering about forty years1 the great ,west1 with its wealth of public lands1 was well traversed by exploratory surveys1 which furnished1 however1 only general outlines for a comprehension of the stratigraphy and structure of mountain and valley1 plain and plateau4 ,to an even less degree was there any realization of the economic possibilities of the vast territory west of the ,mississippi4 ,president ,jefferson1 in planning the ,lewis and ,clark expedition1 had stated his special interest in the mineral resources of the region to be traversed4 ,nearly forty years later ,doctor ,owen was strongly impressed with the commercial promise of the region he surveyed4 ,his reports contain analyses of ores and statistics of production2 he compared the lead output of ,wisconsin1 ,iowa1 and ,illinois with that of ,europe and foretold the value of the iron1 copper1 and zinc deposits of the area2 he outlined the extent of the ,illinois coal field2 and he laid equal emphasis upon the agricultural possibilities of the region4 ,indeed1 so optimistic were ,owen's general conclusions that he referred to his separate township plats1 with their detailed descriptions1 as the basis for his sanguine opinions1 realizing that 8the explorer is apt to become the special pleader40 ,with equal breadth of view and thoroughness of execution the surveys of ,foster and ,whitney laid the foundation for the development of the copper and iron resources of the ,lake ,superior region1 and although these areas were largely wilderness and not adapted to rapid traverse or easy observation the reports on their explorations nevertheless compare most favorably with the contributions of geologists working in the more hospitable regions in the older ,states4 ,the period following the ,civil ,war naturally became one of national expansion1 the faces of many were turned westward1 and exploration of the national domain for its industrial possibilities took on fresh interest4 ,home-seekers and miners largely made up this army of peaceful invasion1 and the winning of the ,west began on a scale quite different from that of the days of the military path-finding expeditions of ,fremont and other ,army officers4 ,thus the nation was aroused to the task of investigating its public lands and ,congress gave the support needed to make geologic exploration possible on a large scale4 ,geologic surveys of a high order were continued in the older ,states1 as shown by the contributions during this period of ,j4 ,p4 ,lesley and ,g4 ,h4 ,cook in the ,east1 ,w4 ,c4 ,kerr1 ,e4 ,w4 ,hilgard1 and ,e4 ,a4 ,smith in the ,south1 and ,j4 ,s4 ,newberry1 ,c4 ,a4 ,white1 ,raphael ,pumpelly1 ,t4 ,c4 ,chamberlin1 ,alexander ,winchell1 and ,t4 ,b4 ,brooks in the ,central ,states4 ,to the north the ,canadian ,survey1 organized in #ahda under ,logan1 had continued under the same sturdy leadership until #ahfi1 when the experienced and talented ,doctor ,selwyn became ,director4 ,as contrasted with the short careers of most of the ,state ,surveys and with the temporary character of all of the ,federal undertakings in geologic investigation1 the continuance of the ,canadian ,geological ,survey for more than half a century under two directors gave opportunity for continuity of effort in making known to the people of the ,dominion its resources and at the same time contributing to the world much pure science4 ,passing with simple mention the two ,government expeditions into the ,black ,hills1 which afforded opportunity for geologic exploration by ,n4 ,h4 ,winchell in #ahgd and by ,jenney and ,newton in #ahge1 the record of geologic work under ,government auspices in the period immediately following the ,civil ,war groups itself around the names of four leaders--,hayden1 ,king1 ,powell1 and ,wheeler4 ,the four organizations1 distinguished commonly by the names of these four masterful organizers1 occupied the ,western field more or less continuously from #ahfg to #ahgh1 and the sum total of their contributions to geography and geology was large indeed4 ,in the words of ,clarence ,king1#aja 8,eighteen hundred and sixty-seven1 therefore1 marks1 in the history of national geological work1 a turning point1 when the science ceased to be dragged in the dust of rapid exploration and took a commanding position in the professional work of the country40 ,together these four expeditions covered half a million square miles1 or more than a third of the area of the ,united ,states west of the one-hundredth meridian1 and the cost of all this work was approximately two million dollars1 which was a small fraction of its value to the nation counting only the impetus given to settlement and utilization4 ,as viewed from a distance of nearly half a century1 these four surveys differed much in plan of organization1 scope of purpose1 and success of execution1 so that comparison would have little value except as possibly bearing upon the work of the larger organization which followed them and became the heir not only to much that had been attained by these pioneer surveys but also to the great task uncompleted by them4 ,so1 if in the earliest days of the present ,united ,states ,geological ,survey there may have been a certain partisanship in tracing derived characters in the new organization1 it is even now worth while to recognize the real origin of much that is credited to present-day development4 ,dr4 ,f4 ,v4 ,hayden was the first of these ,survey leaders to engage in geological exploration4 ,he visited the ,badlands as early as #ahec1 and his connection with subsequent expeditions was interrupted only by his service as a surgeon in the ,federal ,army during the war4 ,in #ahfg1 however1 ,hayden resumed his geologic work as ,united ,states ,geologist in ,nebraska1 operating under direction of the ,commissioner of the ,general ,land ,office4 ,in the following eleven years the activities of the ,hayden ,survey--the 8,geological and ,geographical ,survey of the ,territories0--extended into ,wyoming1 ,colorado1 ,new ,mexico1 ,montana1 and ,idaho1 covering with areal surveys #ajg1jjj square miles4 ,this ,survey1 as might be expected from the long experience of its leader1 made large contributions to stratigraphy1 which involved notable paleontologic work by ,cope1 ,meek1 and ,lesquereux4 ,next in importance was the structural work of ,a4 ,c4 ,peale1 ,w4 ,h4 ,holmes1 ,capt4 ,c4 ,e4 ,dutton1 and ,dr4 ,hayden himself1 and the influence of these expeditions in popularizing geology should not be overlooked4 ,the expedition of #ahga into the geyser region on the upper ,yellowstone resulted in the creation of the first of the national parks4 ,w4 ,h4 ,holmes began his artistic contributions to geology in #ahgb with this ,survey4 ,topographic mapping was added to the geologic exploration1 ,james ,t4 ,gardner and ,a4 ,d4 ,wilson joining the ,hayden ,survey after earlier service on the ,king ,survey and ,henry ,gannett being a member of parties1 first as astronomer and later as topographer in charge4 ,the accomplishment of the ,hayden ,survey itself and the later work of many of its members show that this organization possessed a corps of strong men4 ,the ,king ,survey was a smaller organization1 with ,congressional authorization of definite scope and a systematic plan of operation4 ,the beginning of construction of the ,union ,pacific terminated the period of the railroad surveys under the ,war ,department and afforded opportunity for geologic work that would be more than exploratory3 the opening up of the new country made investigation of its resources logical4 ,this fact was recognized by ,clarence ,king1 who had traversed the same route as a member of an emigrant train with his friend ,james ,t4 ,gardner4 ,his plan to make a geological cross section of the ,cordilleras1 with a study of the resources along the route of the ,pacific railroads1 won the support of ,congress1 and the 8,geological ,exploration of the ,fortieth ,parallel0 was authorized in #ahfg1 with ,clarence ,king as geologist in charge1 under the ,chief of ,engineers of the ,army4 ,field work was begun in the summer of that year1 and it is interesting to note that ,mr4 ,king and his small force of geological assistants--the two ,hagues and ,s4 ,f4 ,emmons--began at the western end of this cross section1 and in this and subsequent years extended the survey from the east front of the ,sierra ,nevada to ,cheyenne1 covering a belt of territory about #ajj miles in width4 ,this comprehensive plan was carried out in the field operations1 and the scientific and economic results were systematically worked up in the reports1 which appeared in #ahgj-hj4 ,the only departure from this plan was a study of the volcanic mountains ,shasta1 ,rainier1 and ,hood1 in #ahgj1 occasioned by an unexpected and unsolicited appropriation for field work1 and that summer's work resulted in the discovery of active glaciers1 the first known within the ,united ,states4 ,the ,fortieth ,parallel ,survey is to be credited with contributions to the knowledge of the stratigraphy of the ,west1 the region traversed being remarkably representative of the stratigraphic column1 to which was added the paleontologic work of ,marsh1 ,meek1 ,hall1 and ,whitfield1 while the attempt was made to interpret the sedimentary record in terms of ,paleozoic1 ,mesozoic1 and ,tertiary geography4 ,king's plan of survey included large use of topographic mapping with astronomic base and triangulation control and contours based upon barometric elevations4 ,the results were pronounced by an unfriendly critic#ajb as 8very valuable1 especially from a geological point of view10 but unfortunate in being the forerunner of work in which ,government geologists 8have presumed to arrogate the control of the fundamental operations of a topographic survey40 ,to the ,king ,survey must be credited the introduction of systematic contour mapping and the use of contour maps for purposes of geology4 ,in two other respects the ,king ,survey contributed largely to future ,government work3 microscopical petrography in the ,united ,states may be said to have begun with the visit of ,professor ,zirkel to this country as a member of this ,survey in #ahge1 and the report of ,j4 ,d4 ,hague on 8,mining ,industry0 was the fitting expression of the emphasis then put on the study of the mineral resources of this newly opened territory1 a subject of investigation that was in large part the true basis of ,king's project rather than simply 8the immediate excuse for the ,survey40 ,an earlier influence in the scientific study of ore deposits had come from ,von ,richthofen's investigation of the ,comstock ,lode in #ahfe and his subsequent work with ,whitney in ,california4 ,the incident of ,king's relation to the diamond fraud in ,arizona in #ahgb furnished a precedent for public servants of a later day2 he investigated the reported find from scientific interest but exposed it with all the zeal of a publicist and truth lover4 ,in a word1 the ,fortieth ,parallel ,survey commands our admiration for its brilliant plan1 thoroughgoing work in field and office1 and high quality of personnel4 ,illustration3 ,j4 ,w4 ,powell ,major ,j4 ,w4 ,powell began his large contribution to ,government surveys with his exploration of the ,grand ,canyon in #ahfi1 the ,congressional recognition of his expedition being limited to an authorization for the issue of rations by the ,war ,department4 ,small appropriations were made in the following years1 and in #ahgd full authorization was given for the continuance of his survey in ,utah under the ,secretary of the ,interior and was followed by the adoption of the name 8,united ,states ,geographical and ,geological ,survey of the ,rocky ,mountain ,region40 ,this organization was the least pretentious of the four operating during this period--it covered less area1 expended less public money1 and published much less--but its contribution to ,american geology is not to be measured by miles or pages but by ideas4 ,its physical environment favored this survey1 and in the work of ,powell1 ,dutton1 and ,gilbert can be seen the beginnings of physiography on the heroic scale exemplified in the ,grand ,canyon and the ,high ,plateaus4 ,the first use of terms like 8base-level of erosion10 8consequent and antecedent drainage10 and 8laccolith0 marked the introduction of new ideas in the interpretation of land sculpture and geologic structure4 ,the daring boat trip of ,powell was no less brilliant than his simple explanation of the ,grand ,canyon itself4 8,the ,united ,states ,geographical ,surveys ,west of the #ajjth ,meridian0 was the title given to the explorations made under ,lieut4 ,g4 ,m4 ,wheeler1 of the ,engineer ,corps1 which began with topographic reconnaissances in ,nevada1 ,utah1 and ,arizona1 specifically authorized by ,congress in #ahgb4 ,from the standpoint of ,american geology this could be better known as the ,gilbert ,survey1 ,mr4 ,g4 ,k4 ,gilbert serving for the three years #ahga-gc1 the later part of the time with the title of chief geological assistant4 ,gilbert's contributions included his description of ,basin ,range structure1 his first account of old ,lake ,bonneville1 and his discussion of the erosion phenomena of the desert country4 ,j4 ,j4 ,stevenson also served later as a geologist of this ,survey1 and ,a4 ,r4 ,marvine1 ,e4 ,e4 ,howell1 ,e4 ,d4 ,cope1 ,jules ,marcou1 and ,i4 ,c4 ,russell were connected with the field parties4 ,captain ,wheeler's own claim for the work of his ,survey emphasized its geographic side1 for he regarded the results as the partial completion of a systematic topographic survey of the country4 ,by #ahgh1 when the ,fortieth ,parallel ,survey had completed the work planned by its chief1 three of these independent surveys still contended for ,federal support and for scientific occupation of the most attractive portions of the ,western country4 ,unrestrained competition of this kind1 even in the public service1 proves as wasteful as unregulated competition in private business1#ajc and ,congress appealed to the ,national ,academy of ,sciences for a plan for ,government surveys to 8secure the best results at the least possible cost40 ,under instructions by ,congress the ,national ,academy considered all the work relating to scientific surveys and reported to ,congress a plan prepared by a special committee1 whose membership included the illustrious names of ,marsh1 ,dana1 ,rogers1 ,newberry1 ,trowbridge1 ,newcomb1 and ,agassiz4 ,this report1 which was adopted by the ,academy with only one dissenting vote1 grouped all surveys--geodetic1 topographic1 land parceling1 and economic--under two distinct heads1 surveys of mensuration and surveys of geology4 ,at that time five independent organizations in three different departments were carrying on surveys of mensuration1 and the ,academy recommended that all such work be combined under the ,coast and ,geodetic ,survey with the new name ,coast and ,interior ,survey4 ,for the investigation of the natural resources of the public domain and the classification of the public lands a new organization was proposed1 the ,united ,states ,geological ,survey4 ,the functions of these two surveys and of a third coordinate bureau in the ,interior ,department1 the ,land ,office1 were carefully defined and their interrelations fully recognized and provided for in the plan presented to ,congress4 ,viewed in the light of #ci years of experience the ,national ,academy plan would be indorsed by most of us as eminently practical1 and the report stands as a splendid example of public service rendered by ,america's leading scientists4 ,the legislation which embodied the entire plan1 however1 failed of passage in ,congress4 ,the natural activity behind the scenes of the conflicting interests represented by those connected with the several surveys may be seen in the legislative history of the moves leading up to the creation of the ,united ,states ,geological ,survey4 ,in the last session of the #deth ,congress the special legislation embodying the recommendations of the ,national ,academy was included in the ,legislative1 ,executive1 and ,judicial ,appropriation bill as it passed the ,house of ,representatives1 while the ,sundry ,civil ,appropriation bill carried an item simply making effective the longer section in the other appropriation bill4 ,the item in the ,legislative appropriation bill created the office of the ,director of the ,geological ,survey1 provided his salary1 and defined his duties1 as well as specifically terminating the operations of the three older organizations4 ,the item in the ,sundry ,civil bill as it passed the ,house appropriated #ajj1jjj for the new ,geological ,survey1 but when this appropriation bill was reported to the ,senate a committee amendment added the words 8of the ,territories10 and further amendments offered on the floor changed the item so as to provide specifically and exclusively for the continuation of the ,hayden ,survey4 ,other amendments provided small appropriations for the completion of the reports of the ,powell and ,wheeler surveys1 and the bill passed the ,senate in this form4 ,the ,legislative ,appropriation bill was similarly pruned1 while in the ,senate1 of all reference to the proposed new organization4 ,this bill1 however1 died in conference1 but in the last hours of the session the conferees on the ,sundry ,civil bill took unto themselves legislative powers and transferred from the dead bill to the pending measure all the language which constitutes the 8organic act0 of the ,united ,states ,geological ,survey4 ,this action was denounced in the ,senate as 8a wide departure from the authority that is possessed by a conference committee10 and it was further stated in debate that the inserted provision which created a new office and discontinued the existing surveys was one 8which neither the ,committee of the ,senate nor the ,senate itself ever saw40 ,this assertion was perhaps parliamentarily sound in that the language was new to the ,sundry ,civil bill1 yet actually the ,senate had only two days before stricken the same proposed legislation from the pending ,legislative ,appropriation bill4 ,however1 the ,house conferees--,representatives ,atkins of ,tennessee1 ,hewett of ,new ,york1 and ,hale of ,maine--had realized their tactical advantage1 and the ,senate1 after a brief debate1 voted on ,march #c to concur in the report of the committee of conference1 thus reversing all their earlier action1 in which the friends of the ,hayden and ,wheeler organizations apparently had commanded more votes than the advocates of the ,national ,academy plan4 ,clarence ,king was appointed first ,director of the ,united ,states ,geological ,survey on ,april #c1 #ahgi1 and began the work of organization4 ,with his proven genius for administration1 ,king promptly resolved the doubt as to the meaning of the term 8national domain0 in the language defining the duties of the ,director by taking the conservative side and limiting the work of the new organization to the region west of the #ajb;d meridian4 ,this region was divided into four geological divisions1 and for economy of time and money field headquarters were established for these divisions4 ,the ,division of the ,rocky ,mountains was placed under ,mr4 ,emmons as geologist in charge1 the ,division of the ,colorado under ,captain ,dutton1 the ,division of the ,great ,basin under ,mr4 ,gilbert1 and the ,division of the ,pacific under ,arnold ,hague4 ,the ,division of the ,colorado was intended as merely temporary for the purpose of bringing to completion the scientific work of the ,powell ,survey4 ,similarly ,dr4 ,hayden was given the opportunity to prepare a systematic digest of his scientific results4 ,this organization of the work and the selection of geologists in charge showed the relation of the new and the old1 and a glance at the personnel of the new ,survey indicates the extent to which the geologic investigation of the ,western country was to continue without interruption4 ,of the twenty-four geologists and topographers listed in the first administrative report1 four had been connected with the ,powell ,survey1 two with the ,hayden1 three with the ,wheeler1 and five with the ,king ,survey4 ,illustration3 ,clarence ,king ,in planning the initial work of the ,united ,states ,geological ,survey1 the ,director speaks of the 8most important geological subjects0 and 8mining industries10 of 8instructive geological structure0 and 8great bullion yield0 in the same sentences1 so that the intent was plain to make the geologic investigations both theoretical and practical4 ,it was expected that the field of operations of this ,federal ,survey would be at once extended by ,congress over the whole ,united ,states1 but the measure making this extension1 which would simply carry out the intent of the framers of the legislation creating the new bureau1 passed the ,house alone1 and it was only by subsequent modification of the wording of appropriation items that the ,united ,states ,geological ,survey became national in scope as well as in name4 ,the critical question of the effective cordination of ,state and ,federal geologic surveys was met by ,director ,king1 who corrected an erroneous impression 8industriously circulated0 by stating his policy to be to urge the inauguration and continuance of ,state surveys4#ajd ,this was the initial step in the cooperation between ,state and ,federal surveys which became effective on a large scale in subsequent years4 ,though the ,geological ,survey has extended its operations over the whole ,united ,states1 its largest activities have always been directed toward the exploration and development of the newer territory in the public-land ,states4 ,all four of its directors had their field training in the ,west3 the name of ,major ,powell1 who succeeded ,king in #ahhj1 is inseparably connected with scientific exploration2 ,charles ,d4 ,walcott1 who was ,director from #ahid to #aijg1 the period of the ,survey's greatest expansion1 made the largest contribution to the ,paleozoic stratigraphy and paleontology of the ,west2 and the present ,director spent seven field seasons in the ,northern ,cascades and one in a mining district in ,utah4 ,the scope of the activities both ,east and ,west as developed during the #ci years since the establishment of the new bureau can be best described1 perhaps1 in terms of its present functions as expressed in the organization of to-day4 ,the growth of the ,survey is measured in the increase of annual appropriation from #ajf1jjj in #ahgi-hj to the amount available for the current year--#a1ibe1ebj1 not including half a million dollars from ,war ,department appropriations being spent in the topographic work of the ,survey4 ,the corresponding increase in personnel has been from #ci1 listed in the first report1 to #iaa holding regular appointments at the present time1 divided among the different branches as follows3 ,a scientific force of #agc in the ,geologic ,branch1 #afi in the ,water ,resources ,branch1 #ga in the ,topographic ,branch1 and #ae in the ,land ,classification ,board1 with a clerical force of #afh divided among the same branches1 and the remainder the technical and clerical employees of the publication and administrative branches4 ,these personnel statistics are not expressive of normal conditions1 since a large number of the topographic engineers are commissioned officers and thus are not included on the civilian roll1 while1 on the other hand1 the classification of the stock-raising homestead lands makes the technical force of the ,water ,resources ,branch unusually large this year4 ,the primary aim of the ,geological ,survey is geologic1 whether directed by authority of law toward the 8examination of the geological structure1 mineral resources1 and products of the national domain10 toward the preparation of the authorized 8reports upon general and economic geology and paleontology10 of the 8geologic map of the ,united ,states10 or of the 8report on the mineral resources of the ,united ,states10 or toward the 8continuation of the investigation of the mineral resources of ,alaska0 or 8chemical and physical researches relating to the geology of the ,united ,states40 ,the spirit and the purpose of the ,survey's work in all these fields are not believed to have materially changed from those of the founders of the science in ,america4 ,from time to time too much emphasis may have appeared to be laid upon applied geology as contrasted with pure science1 yet the report of the ,national ,academy to ,congress in terms placed the stress upon economic resources and referred to paleontology as 8necessarily connected0 with general and economic geology4 ,the practical purpose of geologic research under ,government auspices must be recognized by the administrator1 whether he be the paleontologist like ,walcott1 the philosopher like ,powell1 or the mining geologist like ,king4 ,that the task of steering the true course is no new problem can be seen from the statement of ,owen#aje written #gj years ago1 and these words describe conditions of ,government geological work even to-day3 ,scientific researches1 which to some may seem purely speculative and curious1 are essential as preliminaries to these practical results4 ,further than such necessity dictates1 they have not been pushed1 except as subordinate and incidental1 and chiefly at such periods as1 under the ordinary requirements of public service1 might be regarded as leisure moments2 so that the contributions to science thus incidentally afforded1 and which a liberal policy forbade to neglect1 may be considered1 in a measure1 a voluntary offering1 tendered at little or no additional expense to the department4 ,the increased attention given to mineral resources has been a matter of gradual growth4 ,mr4 ,king early organized a ,division of ,mining ,geology with ,messrs4 ,pumpelly1 ,emmons1 and ,becker as geologists in charge1 to whom were assigned the collection of mineral statistics for the ,tenth ,census4 ,these ,survey geologists and ,director ,king himself held appointments as special agents of the ,census ,bureau1 and on the staff selected for this work appear the names of ,t4 ,b4 ,brooks1 ,edward ,orton1 ,t4 ,c4 ,chamberlin1 ,eugene ,a4 ,smith1 ,george ,little1 ,j4 ,r4 ,proctor1 ,r4 ,d4 ,irving1 ,n4 ,s4 ,shaler1 ,john ,hays ,hammond1 ,bailey ,willis1 and ,g4 ,h4 ,eldridge1 indicating the extent to which the supervision of these inquiries was placed in the hands of economic geologists4 ,this procedure was reverted to by ,director ,walcott and in the last ten years has become a well-established policy1 the statistics of annual production of all the important mineral products being under the charge of geologists1 as best qualified to comprehend the resources of the country4 ,another of these special assistants in #ahhj was ,albert ,williams1 ,jr41 who became the first chief of the ,division of ,mineral ,resources1 in #ahhb4 ,the study of ore deposits1 which may be said to have begun with the ,king ,survey1 was inspired by ,king's own appreciation of the broad geologic relations of the distribution of mineral wealth and by the detailed studies of individual mining districts by his associates1 8based upon facts accurately determined in the light of modern geology40 ,geological surveys have been prosecuted in ,alaska since #ahie1 and in the last few years the annual appropriation for the work has been the same as that made for the expenses of the whole ,survey in the first year of its history4 ,the ,division of ,alaskan ,mineral ,resources is in fact a geological survey in itself1 except that it shares in the administrative machinery of the larger organization and has the advantage of the cooperation of the scientific specialists of the ,survey as they may be needed to supplement its own force4 ,all the investigations in this distant part of the country represent the ,geological ,survey at its best1 for here the organization's long experience in the ,western ,states can be applied to most effective and helpful work on the frontier1 where the geologist and topographer in their exploration do not always follow the prospector but often precede him4 ,undoubtedly no greater factor has contributed to the development of ,alaskan resources than this pioneer work of the ,federal ,survey1 yet the work has also contributed notable additions to the sciences of geology and geography4 ,the first duty laid upon the ,director of the ,geological ,survey in the law of #ahgi was 8the classification of the public lands10 and this phrase undoubtedly expressed the idea of the committee of the ,national ,academy4 ,the same legislation1 however1 contained provision for the further consideration by a commission of the classification and valuation of the public lands1 as also recommended by the ,national ,academy4 ,thus the decision of ,director ,king that the classification intended by ,congress was scientific and was intended for general information and not to aid the ,land ,office in the disposition of land by sale or otherwise was really based upon the deliberate opinion of the ,public ,lands ,commission1 of which he was a member1 that classification would seriously impede rapid settlement of the unoccupied lands4 ,nearly forty years later those who are intrusted with the land-classification work of the ,geological ,survey recognize this familiar argument1 which undoubtedly had much more force in that earlier stage of the utilization of the ,nation's resources of land4#ajf ,the conception of land classification as a business policy on the part of the ,government as a landed proprietor belongs rather to this day of more intensive development4 ,at present current public-land legislation calls for highest use1 and hence official investigation of natural values and possibilities must precede disposition4 ,this type of mineral and hydrographic classification of public lands has been in progress in increasing amount since #aijf1 so that now the ,geological ,survey is the kind of scientific adviser to the ,secretary of the ,interior and ,commissioner of the ,general ,land ,office that may have been contemplated by the ,national ,academy of ,sciences in #ahgh4 ,it is plain1 however1 to everyone at all conversant with ,western conditions that the recent land-classification surveys in ,wyoming1 for instance--detailed geologic surveys which form the basis for the valuation of public coal lands in #dj-;acre units--would have possessed no utility in #ahga1 when the coal-land law was passed but when the demand for railroad fuel had just begun4 ,the land-classification idea is of course the basis of the ,national forest and irrigation movements4 ,the laws of #ahhh and #ahif1 which mark the beginning of active endorsement by ,congress of these conservation movements1 placed upon the ,survey the duties of examining reservoir sites and forest reserves respectively4 ,the earlier of these laws began the investigation of the water resources of the country1 which is still an important phase of the ,survey's activity1 and led to the creation of an independent organization--the ,reclamation ,service4 ,it is easy to trace the beginnings of ,federal reclamation of arid lands in the pioneer work of ,powell1 whose report in #ahgh on the arid region of the ,united ,states was the first adequate statement of the problem of largest use of these lands in terms broader than those of individualistic endeavor4 ,for years1 however1 ,powell's appeal for ,congressional consideration of this ,national task was like the 8voice of one crying in the wilderness40 ,in a somewhat similar way the forestry surveys under the ,geological ,survey helped in the organization of a separate bureau--now the ,forest ,service4 ,the other important ,federal bureau tracing direct relationship to the ,survey is the ,bureau of ,mines1 established in #aiaj1 which continued the investigations in mining technology specifically provided for by ,congress for six years under the ,geological ,survey but in some degree begun in the early days of the ,survey under ,directors ,king and ,powell4 ,another equally important organization of a public nature1 though not a ,federal bureau1 traces its beginnings to the ,geological ,survey3 the ,geophysical ,laboratory of the ,carnegie ,institution1 which now exercises so potent an influence over geologic investigation1 had its origin in the official work of the ,geological ,survey's ,division of ,chemical and ,physical ,research1 and its personnel was at first largely recruited from the ,survey4 ,the highly original experimental work of this laboratory has extended far beyond the scope of the ,survey's work--at least far beyond the scope possible with the ,federal funds available--yet most of the results of these investigations may eventually come under even a strict construction of the language used in the ,survey's appropriation 8for chemical and physical researches relating to the geology of the ,united ,states40 ,the topographic work of the present ,survey continues with constant refinement of standards and economy of methods the work of the earlier organizations4 ,the primary purpose of these topographic surveys is to provide the bases for geologic maps1 yet these topographic maps1 which cover #dj per cent of the area of the ,united ,states1 are used in every type of civil engineering as well as by the public generally4 ,the annual distribution by sale of half a million of these maps is an index of their value to the people4 ,the hot discussion that was waged for years on the question of military versus scientific administration of topographic surveys is in striking contrast with the present concentration of all the topographic mapping under the ,geological ,survey in those areas where it may best serve the needs of the ,army4 ,in #aiaf ,congress specifically recognized the possibility of greater cooperation of this kind1 both in the appropriation made to the ,geological ,survey and in a special appropriation made to the ,war ,department4 ,for a number of years indeed special military information had been contributed to the ,army by the ,survey topographers1 but since ,march #bf1 #aiag1 every ,geological ,survey topographer has worked exclusively on the program of military surveys laid down by the ,general ,staff of the ,army1 and the places of some of the #dd ,survey topographers now in ,france as engineer officers are filled by #cd other reserve engineer officers detailed by order of the ,secretary of ,war to the ,director of the ,geological ,survey to assist in this military mapping and to receive instruction fitting them in turn for topographic service in ,france4 ,the contribution of this civilian service to the military operations in the present emergency forms a fitting conclusion to this review of a century of ,government surveys4 ,at present #bae members of the ,geological ,survey are in uniform1 #ajg as engineer officers1 two of whom are on the staff of the ,american ,commanding ,general in ,france4 ,in the war work carried on in the ,united ,states the ,survey's contribution is by no means limited to military mapping3 the geologists are also mobilized for meeting war needs1 assisting in developing new sources of the essential war minerals1 in speeding up production of mineral products1 in collecting information for the purchasing officers both of our own and of the ,allied governments1 in coperating with the constructing quarter-masters in the location of gravel and sand for structural use and in both general and special examinations of underground water supply and of drainage possibilities at cantonment sites1 and in supplying the ,navy ,department with similar technical data4 ,a special contribution has been the application to arial surveys of photogrammetric methods developed in the ,alaskan topographic work and the perfection of a camera specially adapted to airplane use4 ,the utilization of the ,survey's map engraving and printing plant for confidential and urgent work for both the ,army and ,navy has necessitated postponement of current work for the ,geological ,survey itself4 ,throughout the organization the records1 the methods1 and the personnel which represent the product of many years of scientific activity are all being utilized2 thus is the experience of the past translated into special service in the present crisis4 ,notes4 ,footnote #if3 ,hess1 ,r4 ,h41 ,foundations of ,national ,prosperity1 p4 #ajj4 ,footnote #ig3 ,report ,nat'l ,museum1 #aijd1 pp4 #ahi-gcc4 ,footnote #ih3 ,featherstonhaugh1 ,j4 ,d41 ,am4 ,geol41 #c1 #bbj1 #ahhi4 ,footnote #ii3 ,whitney1 ,mineral ,wealth of the ,united ,states1 pp4 #bdh-bej4 ,footnote #ajj3 ,foster and ,whitney1 #cast ,cong41 #ast session1 ,house ,doc4 #fi1 pp4 #ac-ad1 #ahej4 ,footnote #aja3 ,first ,annual ,rept4 ,u4 ,s4 ,geol4 ,survey1 p4 #d4 ,footnote #ajb3 ,wheeler1 ,report #c;d ,internat'l ,geog4 ,cong41 p4 #dib1 #ahhe4 ,footnote #ajc3 ,the views of the writer on 8natural monopolies0 in the ,government service are set forth in an address delivered at the centennial celebration of the ,u4 ,s4 ,coast and ,geodetic ,survey1 ,april #e1 #aiaf4 7,see ,science1 vol4 #dc1 pp4 #fei-ffe1 ,may #ab1 #aiaf47 ,footnote #ajd3 ,for correspondence on this subject1 see ,minnesota ,geol4 ,survey1 ,eighth ,ann4 ,rept41 #ahhj1 p4 #agc4 ,footnote #aje3 ,owen1 ,d4 ,d41 #cjth ,cong41 #ast sess41 ,senate ,doc4 ,no4 #eg1 p4 #g1 #ahdh4 ,footnote #ajf3 ,this essential difference between present-day requirements and the needs of earlier generations has been discussed by ,w4 ,c4 ,mendenhall1 the geologist in charge of the ,land ,classification ,board of the ,geological ,survey3 ,proceedings #b;d ,pan-,american ,sci4 ,cong41 #aiae-af1 #c1 #gfa4 ,,vi ,,on ,,the ,,development ,,of ,,vertebrate ,,paleontology ,by ,,richard ,,swann ,,lull ,introduction4 ,unlike its sister science of ,invertebrate ,paleontology1 which has been approached so largely from the viewpoint of stratigraphic geology1 that of the vertebrates is essentially a biologic science1 having its inception in the masterly work of ,cuvier1 who is also to be regarded as the founder of comparative anatomy4 ,for long decades1 vertebrate paleontology was simply a branch of comparative anatomy or morphology in that it dealt almost exclusively with the form and other peculiarities of fossil bones and teeth1 often in a more or less fragmentary condition1 very little or no attention being paid to any other system of the creature's anatomy4 ,distribution both in space and in time was recorded1 but the value of vertebrates in stratigraphy was still to be appreciated and has hardly yet come into its own4 ,it is readily seen1 therefore1 that the two departments of paleontology did not enlist the same workers or even the same type of investigators1 for while the two sciences have much in common and should have more1 the vertebratist must1 above all else1 be a morphologist1 with a keen appreciation of form1 and a mind capable of retaining endless structural details and of visualizing as a whole what may be known only in part4 ,the initial work of the brilliant ,cuvier set so high a standard of preparedness and mental equipment that as a consequence1 the number of those engaged in vertebrate research has never been large as compared with the workers in some other branches of science1 but the results achieved by the few who have consecrated their research to the fossil vertebrates has been in the main of a high order4 ,at first1 as has been emphasized1 this work was largely morphological1 dealing both with the individual skeletal elements and later with the bony framework as a whole4 ,then came the endeavor to clothe the bones with sinews and with flesh--to imagine1 in other words1 the life-appearance of the ages-departed form--with such of its habits as could be deduced from structure of body1 tooth1 and limb4 ,next came the working out of systematic series of vertebrates and their marshalling into species1 genera1 and larger groups1 and much time was thus spent1 especially when rapid discovery brought a continual stream of new forms before the systematist1 and hence some appreciation of the countless hosts of bygone creatures which peopled the world in the geologic past4 ,this systematic work1 however1 was based upon the most painstaking morphologic comparisons and so the science was still within the scope of comparative anatomy4 ,in connection with taxonomic research came increasingly tangible evidence in favor of the law of evolution2 investigators turned to the working out of phyletic series showing the actual record of the successive evolutionary changes that the various races had undergone4 ,coupled with this evolutionary evidence came an increased attention to the sequential occurrence in successive geologic strata1 and the stratigraphic distribution of vertebrates became known with greater and greater detail4 ,then followed the assemblage of faunas1 which brought the study of the fossil forms within the realm of historical geology1 rather than being the mere phylogeny of a single race1 and the value of vertebrate fossils as horizon markers became more and more appreciated by the stratigrapher4 ,they serve to supplement the knowledge gained from the invertebrates1 and in this connection are especially valuable in that they often give data concerning continental formations about which invertebrate paleontology is largely silent4 ,rise of ,vertebrate ,paleontology in ,europe4 ,to those who had been nurtured in the belief in a relatively recent creation covering in its entirety a period of but six days1 and occurring but four millenniums before the time of ,christ1 the appearance of the remains of creatures in the rocks1 the like of which no man ever saw alive1 must have given scope to the wildest imaginings concerning their origin and significance2 for many believed that not only had no new forms been added to the world's fauna since the creation1 except possibly by hybridizing1 but that none had become extinct save a very few through the agency of human interference4 ,the supposition was1 therefore1 that such creatures as were thus discovered were still extant in some more remote fastnesses of the world4 ,thus1 our second president1 ,thomas ,jefferson1 who wrote one of the first papers on ,american fossil vertebrates1 published in #agih1 discussed therein the remains of a huge ground-sloth which has since borne the name ,megalonyx jeffersoni4 ,jefferson1 however1 described the great claws as pertaining to a huge leonine animal which he firmly believed was yet living among the mountains of ,virginia4 ,cuvier 7#agfi-ahcb7 has been spoken of as the founder of our science4 ,his opportunity lay in the profusion of bones buried in the gypsum deposits of ,montmartre within the environs of the city of ,paris4 ,cuvier's studies of these remains1 done in the light of his very broad anatomical knowledge1 enabled him to prepare the first reconstructions of fossil vertebrates ever attempted and to bring before the eyes of his contemporaries a world peopled with forms which were utterly extinct4 ,that these creatures were no longer living1 none was a better judge than ,cuvier1 for his prominence was such that material was sent him from all parts of the world1 to which must be added that which he saw in his visits to the various museums of ,europe4 ,he felt it safe1 therefore1 to affirm the unlikelihood of any further discovery of unknown forms among the great mammals of the present fauna of our globe1 and few indeed have been the additions since his day4 ,to ,cuvier is due not alone the masterly contribution to the sister sciences of comparative anatomy and vertebrate paleontology--the ,ossements ,fossiles 7#ahab7--;but he also announced the presence in continental strata of a series of faunas which showed a gradual organic improvement from the earliest such assemblage to the most modern1 an idea of the most fundamental importance and one with which he is rarely credited4 ,he believed in the sudden and complete extinction of faunas1 and the facts then known were in accord with this idea1 as no common genera nor transitional forms connected the creatures of the ,paris gypsum with the mastodons1 elephants1 and hippopotami which the later strata disclosed4 ,it is not remarkable1 therefore1 that ,cuvier advanced his theory of catastrophism to account for these extinctions4 ,he should not1 however1 according to ,depret1 be credited with the idea of successive re-creations1 such as that held by ,d',orbigny and others1 but of repopulation by immigration from some area which the catastrophe1 be it flood or other destructive agency1 failed to reach4 ,cuvier was followed in ,europe by a number of illustrious men1 none of whom1 however1 with the exception of ,sir ,richard ,owen1 possessed his breadth of knowledge of comparative anatomy upon which to base their researches among the prehistoric4 ,the more notable of them may be enumerated before going on to a discussion of the ,american contributions to the science4 ,they were1 first1 ,louis ,agassiz1 a pupil of ,cuvier and later a resident of ,america1 whose researches on the fossil fishes of ,europe are a monumental work1 the result of ten years of investigation in all of the larger museums of that continent1 and which appeared in #ahcc-dc1 while he was yet a young man4 ,the fishes were practically the only fossil vertebrates to come within the scope of his investigations1 for his later time was consumed in the study of glaciers and of recent marine zoology4 ,another student of these most primitive vertebrates who left an enduring monument was ,johannes ,mller4 ,huxley1 ,traquair1 and ,jaekel also did masterly work upon this group1 while ,smith ,woodward of the ,british ,museum is considered the highest living authority upon fossil fishes4 ,of the ,amphibia1 the most famous foreign students were ,brongniart1 ,jaeger1 ,burmeister1 ,von ,meyer1 and ,owen1 although ,owen's claim to eminence lies rather in the investigations of fossil reptiles which he began in #ahci and continued over a period of fifty years of remarkable achievement4 ,not only did he describe the dinosaurs of ,great ,britain in a series of splendidly illustrated monographs1 but extended his researches to the curious reptilian forms from the ,karroo formation of ,south ,africa4 ,it was to him1 moreover1 that the establishment of the true position of the famous ,archopteryx as the earliest known bird and not a reptile is due4 ,von ,meyer also enriched the literature of fossil reptiles1 discussing exhaustively those occurring in ,germany1 while ,huxley's classic work on the crocodiles as well as on dinosaurs1 and the labors of ,buckland1 ,fraas1 ,koken1 ,von ,huene1 ,gaudry1 ,hulke1 ,seeley1 and ,lydekker have added immensely to our knowledge of the group4 ,of the birds1 which at best are rare as fossils1 our knowledge1 especially of the huge flightless moas1 is due largely again to ,owen1 and his realization of the systematic position of ,archopteryx has already been mentioned4 ,the mammals were1 perhaps1 the most prolific source of paleontological research during the nineteenth century1 for1 as ,zittel has said1 ,cuvier's famous investigations on the fossil bones1 mentioned above1 not only contain the principles of comparative osteology1 but also show in a manner which has never been surpassed how fossil vertebrates ought to be studied1 and what are the broad inductions which may be drawn from a series of methodical observations4 ,such was ,cuvier's influence that until ,darwin began to interest himself in mammalian paleontology the study of these forms was conducted entirely along the lines indicated by the ,french savant4 ,this was seen in a large work1 ,osteology of ,recent and ,fossil ,mammalia1 by ,de ,blainville1 which1 although not up to the standard set by the master1 is nevertheless a notable contribution1 as was also the ,osteology prepared by ,pander and ,d',alton4 ,a summary of the knowledge of the fossil ,mammalia up to the year #ahdg is contained in ,giebel's ,fauna der ,vorwelt1 and ,lydekker has done for the mammals in the ,british ,museum what ,smith ,woodward did for the fishes1 producing vastly more than the mere catalogue which the title implies4 ,the first work wherein the fossil mammals were treated genealogically was ,gaudry's ,enchanements du ,monde ,animal1 written in #ahgh4 ,other work on the fossil ,mammalia was done by ,kaup1 who described those from the ,mainz basin and from ,epplesheim near ,worms whence came one of the most famous of prehistoric horses1 the ,hipparion2 this horse1 together with the remarkable proboscidean ,dinotherium1 was described by ,von ,meyer4 ,one of the most remarkable discoveries1 ranking in importance1 perhaps1 next to ,montmartre1 was that of the ,pliocene fauna of ,pikermi near ,athens1 ,greece1 first made known through the publications of ,a4 ,wagner of ,munich and later1 and much more extensively1 through that of ,gaudry 7#ahfb-ahfg74 ,h4 von ,meyer was ,germany's best authority on fossil ,mammalia4 ,after his death the work was carried on by ,quenstedt1 ,oscar ,fraas1 ,schlosser1 ,koken1 and ,pohlig1 among others4 ,in ,france1 rich deposits of fossil mammals were discovered in the ,department of ,puy-de-,dme1 the ,rhone basin1 ,sansan1 ,quercy1 and near ,rheims4 ,these were described by a number of writers1 notably ,croizet and ,jobert1 ,pomel1 ,lartet1 ,filhol1 and ,lemoine4 ,rtimeyer of ,ble was one of the most famous ,european writers on mammalian paleontology1 and his researches were both comprehensive and clothed in such form as to give them a high place in paleontological literature4 ,he studied comparatively the teeth of ungulates1 discussed the genealogy of mammals1 and the relationships of those of the ,old and ,new ,worlds4 ,he was an exponent of the law of evolution as set forth by ,darwin1 and his 8genealogical trees of the ,mammalia show a complete knowledge of all the data concerning the different members in the succession1 and are amongst the finest results hitherto obtained by means of strict scientific methods of investigation0 7,zittel1 ,history of ,geology and ,palontology1 #aija74 ,the mammals of the ,swiss ,eocene have been studied in much detail by ,stehlin4 ,for ,great ,britain1 the most notable contributors were ,buckland in his ,reliqui ,diluvian2 ,falconer1 co-author with ,cautley on the ,tertiary mammals of ,india2 ,charles ,murchison1 who wrote on rhinoceroses and proboscideans2 and more recently ,bush1 ,flower1 ,lydekker1 ,boyd ,dawkins1 ,l4 ,adams1 and ,c4 ,w4 ,andrews4 ,but by far the most commanding figure of all was ,sir ,richard ,owen1 who for half a century stood without a peer as the greatest of authorities on fossil mammals4 ,it was the ,natural ,history of the ,british ,fossil ,mammals and ,birds1 published in #ahdf1 that established ,sir ,richard's reputation4 ,russia has produced much mammalian material1 especially from the ,tertiary of ,odessa and ,bessarabia1 and from the ,quaternary of northern ,russia and ,siberia4 ,these have been described mainly by ,j4 ,f4 ,brandt1 ,a4 von ,nordmann1 but especially by ,mme4 ,m4 ,pavlow of ,moscow4 ,forsyth-,major discovered in #ahhg a fauna contemporaneous with that of ,pikermi in the ,island of ,samos in the ,mediterranean4 ,one of the most remarkable recent discoveries of fossil localities was that announced in #aija by ,mr4 ,hugh ,j4 ,l4 ,beadnell of the ,geological ,survey of ,egypt and ,doctor ,c4 ,w4 ,andrews of the ,british ,museum of ,london1 of numerous land and sea mammals of ,upper ,eocene and ,lower ,oligocene age in northern ,egypt4 ,the exposures lay about #hj miles southwest of ,cairo in the ,faym district and are the sediments of an ancient ,tertiary lake1 a relic of which1 ,birket-el-,qurun1 yet remains4 ,these beds contained ancient ,hyracoidea1 ,sirenia1 and ,zeuglodontia1 but above all1 ancestral ,proboscidea which1 together with those known elsewhere1 enabled ,andrews to demonstrate the origin and evolutionary features of this most remarkable group of beasts4 ,this discovery in the ,faym lends color to the belief that ,africa may have been the ancestral home of at least five of the mammalian orders1 those mentioned above1 together with the ,embrithopoda1 a group unknown elsewhere4 ,this theory had been advanced independently by ,tullberg1 ,stehlin1 and ,osborn1 before the discovery in ,egypt4 ,another ,european worker of pre-eminence who wrote more broadly than the faunal studies mentioned above was ,w4 ,kowalewsky4 ,he discussed especially the evolutionary changes of feet and teeth in ungulates1 a line of research afterward developed in greater detail by the ,americans1 ,cope and ,osborn4 ,south ,america has yielded series of rich faunas which have been exploited by the great ,argentinian1 ,florentino ,ameghino1 and by the ,europeans1 ,owen1 ,gervais1 ,huxley1 ,von ,meyer1 and more recently by ,burmeister and ,lydekker4 ,later exploration and research by ,hatcher and ,scott of ,north ,america will be discussed further on in this paper4 ,vertebrate ,paleontology in ,america4 ,early ,writers4--,having thus summarized paleontological progress in the ,old ,world1 we can turn to a consideration of the work done in the ,new1 especially in the ,united ,states1 because while the ,old ,world investigation has been invaluable1 a science of vertebrate paleontology1 very complete both as to its zoological and geological scope and in the extent and value of published results1 could be built exclusively upon the discoveries and researches made by ,americans4 ,the science of vertebrate paleontology may be said to have had its beginnings in ,north ,america with the activities of ,thomas ,jefferson1 who1 like ,franklin1 felt so strong an interest in scientific pursuits that even the graver duties of the highest office in the gift of the ,american people could not deter him from them4 ,when in #agig ,jefferson came to be inaugurated as vice-president of the ,united ,states1 he brought with him to ,philadelphia not only his manuscript but the actual fossil bones upon which it was based4 ,again in #ahja he was greatly interested in the ,shawangunk mastodon1 despite heavy cares of state1 and in #ahjh made part of the executive mansion in ,washington serve as a paleontological laboratory1 displaying therein for study the bones of proboscideans and their contemporaries which the ,big ,bone ,lick of ,kentucky had produced4 ,jefferson's work would not1 perhaps1 have been epoch-making were it not for its unique chronological position in the annals of the science4 ,jefferson was followed by another man--this time one whose diverging lines of interest led him not into the realm of political service1 but of art1 for ,rembrandt ,peale possessed an enviable reputation among the early painters of ,america4 ,peale published in #ahjb an account of the skeleton of the 8mammoth10 really the mastodon1 ,m4 americanus1 speaking of it as a nondescript carnivorous animal of immense size found in ,america4 ,it was because of the form of the molar teeth that ,peale said of it3 8,if this animal was indeed carnivorous1 which ,i believe cannot be doubted1 though we may as philosophers regret it1 as men we cannot but thank ,heaven that its whole generation is probably extinct40 ,with the work of these men as a beginning1 it is not strange that the more conspicuous ,pleistocene fossils of the ,east should have attracted the attention of many subsequent writers in the first part of the nineteenth century1 nor that the early papers to appear in the ,journal should pertain to proboscideans or to the huge edentate ground-sloths and the aberrant zeuglodons whose bones frequently came to light4 ,therefore a number of men such as ,koch1 both ,sillimans1 ,j4 ,c4 ,warren1 and others made these forms their chief concern4 ,fossil ,footprints4--,among the early writers who concerned themselves with these greater fossils was ,edward ,hitchcock1 sometime president of ,amherst ,college1 and a geologist of high repute among his contemporaries4 ,hitchcock is1 however1 better and more widely known as the pioneer worker on a series of phenomena displayed as in no other place in the region in which he made his home4 ,these are fossil footprints impressed upon the ,triassic rocks of the ,connecticut valley4 ,it was in the ,journal for the year #ahcf 7#bi1 #cjg-cdj7 that ,hitchcock first called attention to the footmarks1 although they had been known and discussed popularly for a number of years previous4 ,james ,deane1 of ,greenfield1 was perhaps the first to appreciate the scientific interest of these phenomena1 but deeming his own qualifications insufficient properly to describe them1 he brought them to the attention of ,hitchcock1 and the interest of the latter never waned until his death in #ahfd4 ,hitchcock wrote paper after paper1 publishing many of them in the ,journal1 again in his ,final ,report on the ,geology of ,massachusetts 7#ahda71 and later in quarto works1 one in the ,memoirs of the ,american ,academy of ,arts and ,sciences and the two others under the authority of the ,commonwealth1 the ,ichnology in #aheh1 and the ,supplement in #ahfe1 the last being a posthumous work edited by his son1 ,charles ,h4 ,hitchcock4 ,hitchcock's conception of the track-makers was more or less imperfect because of the fact that for a long time but a few fragmentary osseous remains were known1 either directly or indirectly associated with the tracks1 while on the other hand the bird-like character of many of the latter and the discovery of huge flightless birds elsewhere on the globe suggested a very close analogy if not a direct relationship4 ,hence 8bird tracks0 they were straightway called1 a designation which it has been difficult to remove1 even though in #ahdc ,owen called attention to the need of caution in assuming the existence of so highly organized birds at so early a period1 especially when large reptiles were known which might readily form very similar tracks4 ,the footprints are now believed to be very largely of dinosaurian origin1 and dinosaurs whose feet corresponded in every detail with the footprints have actually come to light within the same geologic and geographic limitations4 ,this of course refers to the bipedal1 functionally three-toed tracks4 ,of the makers of certain of the obscurer of the quadrupedal trails we are as much in the dark to-day as were the first discoverers of a century ago1 so far as demonstrable proof is concerned4 ,we assume1 however1 that they were the tracks of amphibia and reptiles1 beyond which we may not go with certainty4 ,agassiz1 writing in #ahfe 7,geological ,sketches71 says3 8,to sum up my opinion respecting these footmarks1 ,i believe that they were made by animals of a prophetic type1 belonging to the class of reptiles1 and exhibiting many synthetic characters4 ,the more closely we study past creations1 the more impressive and significant do the synthetic types1 presenting features of the higher classes under the guise of the lower ones1 become4 ,they hold the promise of the future4 ,as the opening overture of an opera contains all the musical elements to be therein developed1 so this living prelude of the creative work comprises all the organic elements to be successively developed in the course of time40 ,of those whose work was contemporaneous with that of ,hitchcock1 but one1 ,w4 ,c4 ,redfield1 wrote on ,triassic phenomena1 and he concerned himself mainly with the fossil fishes of that time1 his first paper on this subject appearing in #ahcg in the ,journal 7#cd1 #bja71 and the last twenty years later4 ,paleozoic ,vertebrates4--,later the vertebrates of the ,paleozoic began to attract attention1 footprints from ,pennsylvania being described by ,isaac ,lea1 beginning in #ahdi1 a notice of his first paper appearing in the ,journal for that year 7#i1 #abd74 ,several papers followed on the reptile ,clepsysaurus4 ,alfred ,king also wrote on the ,carboniferous ichnites1 his work slightly antedating that of ,lea1 but being less authoritative4 ,but by far the most illuminating of the mid-century writers on ,paleozoic vertebrates was ,sir ,william ,dawson1 a very large proportion of whose numerous papers relate to the ,coal ,measures of ,nova ,scotia and their contained plant and animal remains4 ,in #ahec appeared ,dawson's first announcement1 written in collaboration with ,sir ,charles ,lyell1 of the finding of the bones of vertebrates within the base of an upright fossil tree trunk at ,south ,joggins4 ,these bones were identified by ,owen and ,wyman as pertaining to a reptilian or amphibian to which the name ,dendrerpeton acadianum was given4 ,following this were several papers published in the ,quarterly ,journal of the ,geological ,society1 ,london1 describing more vertebrates and associated terrestrial molluscs4 ,in #ahfc ,dawson summarized his discoveries in the ,journal 7#cf1 #dcj-dcb7 under the title of 8,air-breathers of the ,coal ,period10 a paper which was expanded and published under the same title in the ,canadian ,naturalist and ,geologist for the same year4 ,dawson also printed in the same volume the first account of reptilian787 footprints from the coal4 ,thus from time to time there emanated from his prolific pen the account of further discoveries1 both in bones and footprints1 his final synopsis of the air-breathing animals of the ,paleozoic of ,canada appearing in #ahie4 ,the only other group of vertebrates which claimed his attention were certain whales1 on which he occasionally wrote4 ,fishes4--,the fossil fishes from the ,devonian of ,ohio found their first exponent in ,j4 ,s4 ,newberry1 appointed chief geologist of the second geological survey of ,ohio1 which was established in #ahfi4 ,these fishes from the ,devonian shales belonged for the greater part to the curious group of armored placoderms1 the remains of which consist very largely of armor plates with little or no traces of internal skeleton4 ,there was also found in association a shark1 ,cladoselache1 of such marvelous preservation that from some of the ,newberry specimens now in the ,american ,museum of ,natural ,history1 ,new ,york1 ,bashford ,dean has demonstrated the histology of muscle and visceral organs1 in addition to the very complete skeletal remains4 ,newberry's work on these forms1 begun in #ahfh1 has been carried to further completion by ,bashford ,dean and his pupil ,l4 ,hussakof1 as well as by ,c4 ,r4 ,eastman4 ,newberry's other paleontological work was with the ,carboniferous fishes of ,ohio1 the ,carboniferous and ,triassic fishes of the region from ,sante ,f to the ,grand and ,green rivers1 ,colorado1 and on the fishes and plants of the ,newark system of the ,connecticut valley and ,new ,jersey4 ,he also discussed certain mastodon and mammoth remains1 and those of the peccary of ,ohio1 ,dicotyles4 ,joseph ,leidy 7#ahbc-ahia74 ,we now come to a consideration of the work of ,joseph ,leidy1 one of the three great pioneers in ,american vertebrate paleontology1 for if we disregard the work of ,hitchcock and others on the fossil footprints1 few of the results thus far obtained were based upon the fruits of organized research4 ,leidy began his publication in #ahdg and continued to issue papers and books from time to time until the year #ahib1 having published no fewer than #bai paleontological titles1 and #eec all told4 ,his earlier paleontological researches were exclusively on the ,mammalia1 which were then coming in from the newly discovered fossil localities of the ,west4 ,the discovery of these forms1 one of the most notable events in the history of our science1 will bear re-telling4 ,the first announcement was made in #ahdg1 when ,hiram ,a4 ,prout of ,st4 ,louis published in the ,journal 7#c1 #bdh-bej7 the description of the maxillary bone of 8,palotherium0 7 ,titanotherium proutii7from near ,white ,river1 ,nebraska4 ,this at once drew the attention of geologists and paleontologists to the ,bad ,lands1 or ,mauvaises ,terres1 which were to prove so highly productive of fossil forms4 ,about the same time ,s4 ,d4 ,culbertson of ,chambersburg1 ,pennsylvania1 submitted to the ,academy of ,natural ,sciences at ,philadelphia some fossils sent to him from ,nebraska by ,alexander ,culbertson4 ,these were afterward described by ,leidy in the ,proceedings of the ,academy1 together with the paleotheroid jaw1 in addition to which three other collections which had been made were also placed at his disposal for study4 ,this aroused the interest of ,doctor ,spencer ,f4 ,baird of the ,smithsonian ,institution1 who sent ,t4 ,a4 ,culbertson to the ,bad ,lands to make further collections4 ,the latter was successful in securing a valuable series of mammalian and chelonian remains4 ,these1 together with other specimens from the same locality1 were sent to ,leidy1 for1 as ,baird remarked1 ,leidy1 although only thirty years of age1 was the only anatomist in the ,united ,states qualified to determine their nature4 ,the outcome of ,leidy's study of this material was 8,the ,ancient ,fauna of ,nebraska10 published in #ahec1 and constituting the most brilliant work which up to that time ,american paleontology had produced4 ,leidy's determinations1 which are in the main correct1 are the more remarkable when it is realized that he had little recent osteological material for comparative study4 ,the forms thus described by him were new to science1 of a more generalized character than those now living1 and yet their distinguished describer recognized1 either at that time or a little later1 their true relationship to the modern types4 ,the extent of ,leidy's anatomical knowledge was almost ,cuvierian1 and ,cuvier-like he established the fact of the presence of the rhinoceroses1 then unheard of in the ,american fauna1 from a few small fragments of molar teeth1 an opinion shortly to be fully sustained through the finding of complete molars and the entire skull of the same individual animal4 ,leidy next turned his attention to the huge edentates1 which he studied exhaustively1 publishing his results in the form of a memoir in #ahee1 two years after the appearance of the 8,ancient ,fauna40 ,extinct fishes of the ,devonian of ,illinois and ,missouri and the ,devonian and ,carboniferous of ,pennsylvania were made the subjects of his next researches1 after which he described the peccaries of ,ohio1 and later1 in a much larger and most important work1 the ,cretaceous reptiles of the ,united ,states 7#ahfe74 ,most of the fossils discussed in this last work are from the ,new ,jersey ,cretaceous marls and of them the most notable was the herbivorous dinosaur ,hadrosaurus1 the structure and habits of which1 together with its affinities with the ,old ,world iguanodons1 ,leidy described in detail4 ,from ,leidy's descriptions and with his aid1 ,waterhouse ,hawkins was enabled to restore a replica of the skeleton in a remarkably efficient way4 ,this restoration for a long time graced the museum of the ,philadelphia ,academy of ,natural ,sciences and there was a plaster replica of it in the ,united ,states ,national ,museum4 ,these1 together with plaster replicas of ,iguanodon from the ,royal ,college of ,surgeons in ,london1 gave to ,americans their first real conceptions of members of this most remarkable group4 ,the associated fossils from the ,new ,jersey marls were chiefly crocodiles and turtles4 ,from #ahec to #ahff ,f4 ,v4 ,hayden was carrying on a series of most energetic explorations in the ,west1 especially in ,nebraska and ,dakota as then delimited1 returning from each trip laden with fossils which were given to ,leidy for determination4 ,the results appeared in #ahfi in ,leidy's ,extinct ,mammalian ,fauna of ,dakota and ,nebraska1 published as volume #g of the ,journal of the ,philadelphia ,academy4 ,in this large volume no fewer than seventy genera and numerous species of forms1 many of them new to science1 were described1 representing many of the principal mammalian orders2 horses were1 however1 especially conspicuous4 ,this last group led ,leidy to the conclusion1 afterward emphasized by ,huxley1 that ,north ,america was the home of the horse in geologic time1 there being here a greater representation of different species than in any recent fauna of the world4 ,leidy's interest in the horses1 for the forwarding of which he made a large collection of recent material1 extended over many years1 as his first paper on the subject bears the date of #ahdg1 the last that of #ahij4 ,next came the discovery of ,eocene material from the vicinity of ,fort ,bridger1 ,wyoming1 geologically older than the ,nebraska and ,dakota formations4 ,this1 together with specimens from the ,green ,river and ,sweetwater ,river deposits of ,wyoming and the ,john ,day ,river 7,oligocene7 of ,oregon1 was also referred to ,leidy1 and added yet more to the list of newly discovered species with which he had already become familiar in his earlier researches4 ,the results of this study were published by the ,hayden ,survey in #ahgc1 under the title 8,contributions to the ,extinct ,vertebrate ,fauna of the ,western ,territories40 ,this was the last of ,leidy's major works1 but he continued up to the time of his death to report to the ,academy concerning the various fossil forms that were submitted to him for identification4 ,of such reports the most important was one on the fossils of the phosphate beds of ,south ,carolina1 published in the ,journal of the ,academy in #ahhg4 ,as a paleontologist1 ,leidy ranks with ,cope and ,marsh high among those who enriched the ,american literature of the subject1 but it must be remembered that this was but a single aspect of his many-sided scientific career1 for he made many contributions of high order to botany1 zoology1 and general and comparative anatomy as well1 nor did his knowledge and usefulness as an instructor of his fellow men keep within the limitations of these subjects4 ,othniel ,charles ,marsh 7#ahca-ahii74 ,the sixth decade of the nineteenth century saw the beginning of the labors of several paleontologists who1 like ,leidy1 were destined to raise the science of fossil vertebrates in ,america to the level of attainment of the ,old ,world4 ,they were1 among others1 ,othniel ,charles ,marsh and ,edward ,drinker ,cope4 ,of these the names of ,marsh and ,cope are linked together by the brilliance of their attainments1 their contemporaneity1 and the rivalry which the similarity of their pursuits unfortunately engendered4 ,marsh produced his first paleontological paper in #ahfb 7#cc1 #bgh71 ,cope in #ahfd1 but the latter died first1 so that his life of research was shorter4 ,illustration3 ,o4 ,c4 ,marsh ,to ,professor ,marsh should be given credit for the first organized expedition designed exclusively for the collection of vertebrate remains1 the results of which contain so much material that it has not yet entirely seen the light of scientific exposition4 ,marsh's first trip to the ,west was in #ahfh1 the first formal expedition being organized two years later4 ,these expeditions1 of which there were four1 were privately financed except for the material and military escort furnished by the ,united ,states ,government1 and consisted of a personnel drawn entirely from the graduate or undergraduate body of ,yale ,university4 ,these parties explored ,kansas1 ,nebraska1 ,wyoming1 ,utah1 and ,oregon1 and returned laden with material from the ,cretaceous and ,tertiary formations of the ,west4 ,some of this is of necessity somewhat fragmentary1 but type after type was secured which1 with his exhaustive knowledge of comparative anatomy1 enabled ,marsh to announce discovery after discovery of species1 genera1 families1 and even orders of mammals1 birds1 and reptiles which were unknown to science4 ,the year #ahgc saw the last of the student expeditions1 and thereafter until the close of his life the work of collecting was done under ,marsh's supervision1 but by paid explorers1 many of whom had been his scouts and guides in the formal expeditions or had been especially trained by him in the ,east4 ,in #ahhb1 after fourteen years of the experience thus gained1 ,marsh was appointed vertebrate paleontologist to the ,united ,states ,geological ,survey1 which relieved him in part of the personal expense connected with the collecting1 although up to within a short time of his death his own fortune was very largely spent in enlarging his collections4 ,after his connection with the ,survey was established1 ,marsh had two main purposes in view in making the collections3 7#a7 to determine the geological horizon of each locality where a large series of vertebrate fossils was found1 and 7#b7 to secure from these localities large collections of the more important forms sufficiently extensive to reveal1 if possible1 the life histories of each4 ,marsh believed that the material thus secured would serve as key or diagnostic fossils to all horizons of our western geology above the ,paleozoic1 a belief in which he was in advance of his time1 for few of his contemporaries appreciated the value of vertebrates as horizon markers4 ,the result of the fulfilment of his second purpose saw the accumulation of huge collections from all horizons above the ,triassic and some ,paleozoic and ,triassic as well4 ,these contained some very remarkable series1 each of which ,marsh hoped to make the basis of an elaborate monograph to be published under the auspices of the ,survey4 ,one can visualize the scope of his ambitions by the fact that no fewer than twenty-seven projected quarto volumes1 to contain at least #hej lithographic plates1 were listed by him in #ahgg4 ,these covered1 among other groups1 the toothed birds 7,odontornithes71 ,dinocerata1 horses1 brontotheres1 pterodactyls1 mosasaurs and plesiosaurs1 monkeys1 carnivores1 perissodactyls and artiodactyls1 crocodiles1 lizards1 dinosaurs1 various birds1 proboscideans1 edentates and marsupials1 brain evolution1 and the ,connecticut ,valley footprints4 ,much was done towards the preparation of these memoirs1 as evidenced by the long list of preliminary papers1 admirably illustrated by woodcuts which were to form the text figures of the memoirs1 which appeared with great regularity in the pages of the ,journal for a period of thirty years4 ,of the actual memoirs1 however1 but two had been published at the time of ,marsh's death in #ahii--the ,odontornithes in #ahhj and the ,dinocerata in #ahhd4 ,one must not overlook1 however1 the epoch-making ,dinosaurs of ,north ,america1 which was published by the ,survey in #ahif1 although it was not in the form nor had it the scope of the proposed monographs4 ,this was not due to lack of application1 for ,professor ,marsh was an indefatigable worker1 but rather to the fact that the program was of such magnitude as to necessitate a patriarchal life span for its consummation4 ,as it is1 ,professor ,marsh's fame rests first upon his ability and intrepidity as a collector1 ready himself to brave the very certain hardships and dangers which beset the field paleontologist in the pioneer days1 and also by his judgment and command of men to secure the very adequate services of others and so to direct their endeavors that the results were of the highest value4 ,the material witness to ,marsh's skill as a collector lies in the collections of the ,peabody ,museum at ,yale and in the ,marsh collection at the ,united ,states ,national ,museum1 the latter secured through the funds of the ,united ,states ,geological ,survey4 ,together they constitute what is possibly the greatest collection of fossil vertebrates in ,america1 if not in the world2 individually1 they are second only to that of the ,american ,museum in ,new ,york ,city1 the result of the combined labors of ,osborn and ,cope and their very able corps of assistants4 ,as a scientist ,marsh possessed in large measure that wide knowledge of comparative anatomy so necessary to the vertebrate paleontologist1 and as a consequence was not only able to recognize affinities and classify unerringly1 but also to recognize the salient diagnostic features of the form before him and in few words so to describe them as to render the recognition of the species by another worker relatively easy4 ,the publication of hundreds of these specific diagnoses in the ,journal constitutes a very large and valuable part of that periodical's contribution to the advancement of our science4 ,marsh's method of indicating forms by so brief a statement leaves much to be done1 however1 in the way of further description of his types1 which in many instances were but partially prepared4 ,yet another important service which ,marsh rendered to science was the restoration of the creatures as a whole1 made with the most painstaking care and precision through assembling the drawings of the individual bones4 ,these restorations have become classic1 embracing as they did a score or more of forms1 of beast1 bird1 and reptile4 ,they also were published first in the ,journal1 although they have subsequently been reproduced in text-books and other works the world over4 ,part of ,marsh's popular reputation1 at least1 which was second to that of no other ,american in his line1 was due to his skill in attaining publicity1 for his papers1 of whatever extent1 were carefully and methodically sent to correspondents in the uttermost parts of the earth1 and thus the ,marsh collection has reflected the fame of its maker4 ,edward ,drinker ,cope 7#ahdj-ahig74 ,the third great name in ,american vertebrate paleontology1 that of ,edward ,drinker ,cope1 stands out in sharp contrast with the other two1 although in the range of his interests he was probably more nearly comparable with ,leidy than with ,marsh4 ,the beginning of ,cope's scientific labors dates from #ahei1 the year made famous in the annals of science by the appearance of ,darwin's ,origin of ,species4 ,it is not surprising1 therefore1 that matters evolutional should have interested him to the very end of his career4 ,cope was not merely a paleontologist1 but was interested in recent forms1 especially the three lower classes of vertebrates1 to such an extent that his work therewith is highly authoritative and in some respects epoch-making4 ,thirty-eight years of almost continual toil were his1 and the mere mass of his literary productions is prodigious1 especially when one realizes that1 unlike those of a writer of fiction1 they were based on painstaking research and philosophical thought4 ,the greater part of ,cope's life was spent in or near ,philadelphia except for his western explorations1 and he is best known as professor of geology and paleontology in the ,university of ,pennsylvania1 although he served other institutions as well4 ,cope's early work was among the amphibia and reptiles1 his first paleontological paper1 the description of ,amphibamus grandiceps1 appearing in #ahfe4 ,this year he also began his studies of the mammals1 especially the ,cetacea1 both living and extinct1 from the ,atlantic seaboard4 ,the next year saw the beginning of his work on the material from the ,cretaceous marls of ,new ,jersey1 describing therefrom one of the first carnivorous dinosaurs1 ,llaps1 to be discovered in ,america4 ,in #ahfh ,cope began to describe the vertebrates from the ,kansas chalk and three years later made his first exploration of these beds4 ,this led to his connection with the ,united ,states ,geological ,survey of the ,territories under ,hayden1 and to continued exploration of ,wyoming and ,colorado in #ahgb and #ahgc4 ,the material thus gained1 consisting of fishes1 mosasaurs1 dinosaurs1 and other reptiles1 was described in the ,transactions of the ,american ,philosophical ,society as well as in the ,survey ,bulletins4 ,in #ahge these results were summarized in a large quarto volume entitled 8,vertebrata of the ,cretaceous formations of the ,west40 ,subsequent summers were spent in further exploration of the ,bridger1 ,washakie1 and ,wasatch formations of ,wyoming1 the ,puerco and ,torrejon of ,new ,mexico1 and the ,judith ,river of ,montana4 ,the material gathered in ,new ,mexico proved particularly valuable1 and led to the publication in #ahgg of another notable volume entitled 8,report upon the ,extinct ,vertebrata obtained in ,new ,mexico by ,parties of the ,expedition of #ahgd40 ,material was now accumulating so fast as to necessitate the concentration of ,cope's own time on research1 so that1 while he continued to make brief journeys to the ,west1 the real work of exploration was delegated to ,charles ,h4 ,sternberg and ,j4 ,l4 ,wortman1 both of whom became subsequently very well known1 the former as a collector whose active service has not yet ceased1 the latter as an explorer and later an investigator of extremely high promise4 ,as early as #ahfe1 ,cope began no fewer than five separate lines of research which he pursued concurrently for the remainder of his career4 ,on the fishes1 he became a high authority in the larger classification1 owing to his researches into their phylogeny1 for which a knowledge of extinct forms is imperative4 ,on amphibia1 he wrote more voluminously than any other naturalist1 discussing not only the morphology but the paleontology and taxonomy as well4 ,in this connection must be mentioned not only ,cope's exploration and collections in the ,permian of ,ohio and ,illinois1 but especially the remains from the ,texas ,permian1 first received in #ahgg1 upon which some of his most brilliant results were based2 these of course included reptilian as well as amphibian material4 ,his third line of research1 the ,reptilia1 is in part included in the foregoing1 but also embraced the reptiles of the ,bridger and other ,tertiary deposits1 those of the ,kansas ,cretaceous1 and the ,cretaceous dinosaurs4 ,up to #ahfh ,leidy alone was engaged in research in the ,west1 but that year saw the simultaneous entrance of ,marsh and ,cope into this new field of research1 and their exploration and descriptions of similar regions and forms soon led to a rivalry which in turn developed into a most unfortunate series of controversies1 mainly over the subject of priority4 ,this resulted in a permanent rupture of friendship and the division of ,american workers into two opposing camps to the detriment of the progress of our science4 ,this breach has now been happily healed1 and for a number of years the degree of mutual good will and aid on the part of our workers has been of the highest sort4 ,the extent of the western fossil area1 and particularly the explorations of three of ,cope's aids1 ,wortman in the ,big ,horn and ,wasatch basins1 ,baldwin in the ,puerco of ,new ,mexico1 and ,cummins in the ,permian of ,texas1 gave him so fruitful a field of endeavor that the occasion for jealous rivalry was largely removed4 ,the most manifest result of ,cope's western work was the publication in #ahhc of his ,vertebrata of the ,tertiary ,formations of the ,west1 which formed volume #c of the quarto publications of the ,hayden ,survey4 ,this huge book contains more than #ajjj pages and #hj plates and has been facetiously called 8,cope's ,bible40 ,cope's philosophical contributions1 which covered the domains of evolution1 psychology1 ethics1 and metaphysics1 began in #ahfh with his paper on ,the ,origin of ,genera4 ,in evolution he was a follower of ,lamarck1 and as such1 with ,hyatt1 ,ryder1 and ,packard1 was one of the founders of the so-called ,neo-,lamarckian ,school in ,america4 ,cope's principal contribution1 set forth in his ,factors of ,organic ,evolution1 is the idea of kinetogenesis or mechanical genesis1 the principle that all structures are the direct outcome of the stresses and strains to which the organism is subjected4 ,weismann's forcible attack on the transmission theory did not shake ,cope's faith in these doctrines1 for he claimed that the paleontological evidence for the inheritance of such characters as are apparently the result of individual modification was too strong to be refuted4 ,cope was more like ,lamarck than any other naturalist in his mental make-up as well as his ideas4 ,he was also1 like ,haeckel1 given to working out the phylogeny of whatever type lay before him1 and in many instances arrived marvellously near the truth as we now see it4 ,associated for a while with ,a4 ,s4 ,packard1 ,cope soon became chief editor and proprietor of the ,american ,naturalist1 which was for many years his main means of publication and thus served our science in a way comparable to the ,journal4 ,as ,osborn says by way of summation3 8,cope is not to be thought of merely as a specialist in ,paleontology4 ,after ,huxley he was the last representative of the old broad-gauge school of anatomists and is only to be compared with members of that school4 ,his life work bears marks of great genius1 of solid and accurate observation1 and at times of inaccuracy due to bad logic or haste and overpressure of work4444 ,as a comparative anatomist he ranks both in the range and effectiveness of his knowledge and his ideas with ,cuvier and ,owen4444 ,as a natural philosopher1 while far less logical than ,huxley1 he was more creative and constructive1 his metaphysics ending in theism rather than agnosticism40 #ahgj-ahhj4 ,the seventh decade was productive of comparatively few great names in the history of our science1 but two1 ,j4 ,a4 ,ryder and ,samuel ,w4 ,williston1 being notable contributors4 ,the former produced but few papers and those between #ahgg and #ahib1 yet they were of note and such was their influence that he is named with ,hyatt1 ,packard1 and ,cope as one of the founders of the ,neo-,lamarckian ,school of evolutionists in ,america4 ,ryder was a particular friend and a colleague of ,cope1 as they were both concerned with the back-boned animals1 while the other two were invertebratists4 ,ryder wrote on mechanical genesis of tooth forms and on scales of fishes1 also on the morphology and evolution of the tails of fishes1 cetaceans1 and sirenians1 and of the other fins of aquatic types4 ,he did1 on the other hand1 practically no systematic or descriptive work4 ,williston1 on the contrary1 has had a long and varied career as an investigator and as an educator4 ,trained at ,yale1 he prepared for medicine1 and much of his teaching has been of human anatomy1 both at ,yale and at the ,university of ,kansas where he served for a number of years as dean of the ,medical ,school4 ,he is also a student of flies1 and as such not only the foremost but indeed almost the only dipterologist in the ,united ,states4 ,but it is with his work as a vertebrate paleontologist that we are chiefly concerned1 and here again he stands among the foremost4 ,his initial work and training in this department of science were with ,marsh1 for whom he spent many months in field work1 collecting largely in the ,niobrara ,cretaceous of ,kansas4 ,he did1 however1 no research while with ,marsh1 owing to the latter's disinclination to foster such work on the part of his associates4 ,williston began his publications in #ahgh and has continued them until the present1 working mainly with ,cretaceous mosasaurs1 plesiosaurs1 and pterodactyls4 ,of late1 since his transference to the ,university of ,chicago1 where as professor of paleontology and director of the ,walker ,museum he has served since #aijb1 his interest has lain mainly among the ,paleozoic reptiles and amphibia4 ,williston's more notable works are ,american ,permian ,vertebrates and ,water ,reptiles of the ,past and ,present1 wherein he sets forth his views of the phylogenesis and taxonomy of the reptilian class4 ,he is at present at work on the evolution of the reptiles1 a volume which is eagerly awaited by his colleagues4 ,it is in morphology that ,williston's greatest strength lies and some of his most effective work on the mosasaurs has appeared in the ,journal4 #ahhj-aijj4 ,the next decade1 that of #ahhj-ahij1 saw a number of notable additions to the workers in vertebrate paleontology3 ,henry ,f4 ,osborn1 ,w4 ,b4 ,scott1 ,r4 ,w4 ,shufeldt1 ,j4 ,l4 ,wortman1 ,george ,baur1 ,f4 ,a4 ,lucas1 and ,f4 ,w4 ,true4 ,shufeldt is our highest authority on the osteology of birds1 both recent and extinct1 having recently described all of the extinct forms contained in the ,marsh collection2 ,true wrote of ,cetacea2 ,lucas of marine and ,pleistocene mammals and birds1 and has also written popular books on prehistoric life4 ,lucas's greatest service1 however1 lies in the museums1 where he has manifested a genius second to none in the installation of mute evidences of living and past organisms4 ,wortman was for a time associated with ,cope1 later with ,osborn in the ,american ,museum1 again at the ,carnegie ,museum at ,pittsburgh1 and finally at ,yale in research on the ,bridger ,eocene portion of the ,marsh collection4 ,his work has been chiefly the perfection of field methods in vertebrate paleontology1 and as a special investigator of ,tertiary ,mammalia1 treating the latter largely from the morphologic and taxonomic standpoints4 ,wortman's ,yale results on the carnivores and primates of the ,eocene1 as yet unfinished1 were published in the ,journal in #aija-aijd4 ,william ,b4 ,scott is a graduate of ,princeton1 and has spent thirty-four years in her service as ,blair ,professor of ,geology and ,paleontology4 ,his first publication1 in #ahgh1 issued in conjunction with ,osborn and ,speir1 described material collected by them in the ,eocene formations of the ,west1 and since that time ,scott's research has been entirely with the mammals1 on which he is one of our highest authorities4 ,his most notable works have been a ,history of ,land ,mammals of the ,western ,hemisphere1 #aiac1 and the results of the ,patagonian expeditions by ,hatcher1 which are published in a quarto series in conjunction with ,w4 ,j4 ,sinclair1 although they are the authors of separate volumes1 ,scott's work being mainly on the carnivores and edentates of the ,santa ,cruz formation4 ,it is as a systematist in research and as an educator that ,scott has attained his highest usefulness4 ,the man who1 next to the three pioneers1 has attained the highest reputation in vertebrate paleontologic research1 is ,henry ,fairfield ,osborn4 ,graduate of ,princeton in the same class that produced ,scott1 ,osborn served for a time as professor of comparative anatomy in that institution1 and in #ahia was called to ,new ,york to organize the department of zoology in ,columbia ,university and that of vertebrate paleontology in the ,american ,museum of ,natural ,history4 ,he had1 early in his career1 gone west in company with ,professor ,scott1 and had collected material from the ,eocene formation of ,wyoming1 upon which they based their first joint paper in #ahgh1 ,osborn's first independent production1 a memoir on two genera of ,dinocerata1 appearing in #ahha4 ,a number of papers followed1 on the ,mesozoic ,mammalia1 on ,cope's tritubercular theory1 and on certain apparent evidences for the transmission of acquired characters4 ,it was1 however1 with his acceptance of the ,new ,york responsibilities1 especially at the ,american ,museum1 that ,osborn's most significant work began4 ,aided first by ,wortman and ,earle1 later by ,w4 ,d4 ,matthew and others1 he has built up the greatest and most complete collection of fossil vertebrates extant2 its value1 however1 was largely enhanced through the purchase of the private collection of ,professor ,cope1 which of course included a large number of types4 ,the ,american ,museum collection thus contains not only a vast series of representative specimens from every class and order of vertebrates1 secured by purchase or expedition from nearly all the great localities of the world1 but an exhibition series of skulls and partial and entire skeletons and restorations which no other institution can hope to equal4 ,based upon this wonderful material is a large amount of research1 filling many volumes1 published for the greater part in the bulletin and memoirs of the ,museum4 ,this research is not only the product of the staff1 including ,walter ,granger1 ,barnum ,brown1 ,w4 ,d4 ,matthew1 and ,w4 ,k4 ,gregory1 but also of a number of other ,american and some foreign paleontologists as well4 ,professor ,osborn's own work has been voluminous1 his bibliography from #ahgg to #aiaf containing no fewer than #dda titles1 ranging over the fields of paleontology1--which of course includes the greater number--geology1 correlation and paleogeography1 evolutionary principles exemplified in the ,mammalia1 man1 neurology and embryology1 biographies1 and the theory of education4 ,in paleontology1 ,osborn's researches have been largely with the ,reptilia and ,mammalia1 partly morphological1 but also taxonomic and evolutional4 ,faunistic studies have also been made of the mammals4 ,of his published volumes the most important are1 first1 the ,age of ,mammals 7#aiaj71 in which he treats not of evolutionary series of phylogenies1 but of faunas and their origin1 migrations1 and extinctions1 and of the correlation of ,old and ,new ,world ,tertiary deposits and their contents4 ,men of the ,old ,stone ,age 7#aiaf7 is an exhaustive treatise and is the first full and authoritative ,american presentation of what has been discovered up to the present time throughout the world in regard to human prehistory4 ,in his latest volume1 ,the ,origin and ,evolution of ,life 7#aiag71 ,osborn presents a new energy conception of evolution and heredity as against the prevailing matter and form conceptions4 ,in this volume there is summed up the whole story of the origin and evolution of life on earth up to the appearance of man4 ,this last book is novel in its conceptions1 but it is too early as yet to judge of the acceptance of ,osborn's theses by his fellow workers in science4 ,since the death of ,professor ,marsh1 ,osborn has served as vertebrate paleontologist to the ,united ,states ,geological ,survey1 and has in charge the carrying through to completion of the many monographs proposed by his distinguished predecessor4 ,one of these1 that on the horned dinosaurs1 has been completed by ,hatcher and ,lull 7#aijg71 another on the stegosaurian dinosaurs has been carried forward by ,c4 ,w4 ,gilmore of the ,united ,states ,national ,museum1 while under ,osborn's own hand are the memoirs on the titanotheres 7aided by ,w4 ,k4 ,gregory71 the horses1 and the sauropod dinosaurs4 ,of these1 the first1 when it shall have been completed1 promises to be the most monumental and exhaustive study of a group of fossil organisms ever undertaken4 ,as a leader in science1 a teacher and administrator1 ,professor ,osborn's rank is high among the leading vertebratists4 ,he is remarkably successful in his choice of assistants and in stimulating them in their productiveness so that their combined results form a very considerable share of the later literature in ,america4 ,the ninth decade ushered in the work of a valuable group of students1 of whom ,john ,bell ,hatcher should be mentioned in particular1 as his work is done4 ,graduate of ,yale in #ahhd1 he spent a number of years assisting his teacher1 ,professor ,marsh1 mainly in the field1 collecting during that time1 either for ,yale or for the ,united ,states ,geological ,survey1 an enormous amount of very fine material1 especially from the ,west1 although he also collected in the older ,tertiary and ,potomac beds near ,washington4 ,in the ,west he secured no fewer than #aje titanothere skulls1 explored the ,tertiary1 ,judith ,river1 and ,lance formations1 collected and in fact virtually discovered the remains of the ,cretaceous mammals and of the horned dinosaurs which he was later privileged to describe4 ,he then 7#ahic7 went to ,princeton1 which he served for seven years1 his principal work being explorations in ,patagonia for the ,e4 and ,m4 ,museum1 one direct result of which was the publication of a large quarto on the narrative of the expedition and the geography and ethnography of the region4 ,going to the ,carnegie ,museum in ,pittsburgh in #aijj1 ,hatcher carried forward the work of exploration and collecting begun for that institution by ,wortman1 and as a partial result prepared many papers1 the principal ones being memoirs on the dinosaurs ,haplocanthosaurus and ,diplodocus4 ,in #aijc1 with ,t4 ,w4 ,stanton of the ,united ,states ,geological ,survey1 ,hatcher explored the ,judith ,river beds and together they settled the vexatious problem of their age1 the published results appearing in #aije1 after ,hatcher's death4 ,his last piece of research1 begun in #aijb and continued until his death in #aijd1 was an elaborate monograph on the ,ceratopsia1 one of the many projected by ,marsh4 ,of this memoir ,hatcher had completed some #aej printed quarto pages1 giving a rare insight into the anatomy of these strange forms4 ,the final chapters1 however1 which were based very largely upon ,hatcher's own opinions1 had to be prepared by another hand4 ,despite his early death1 therefore1 ,hatcher rendered a very signal service to ,american paleontology--in exploration1 stratigraphy1 morphology1 and systematic revision--and his activity in planning new fields of research1 such1 for instance1 as the exploration of the ,antarctic continent1 gave promise of further high attainment1 when his hand was arrested by death4 ,summary4 ,it is not surprising that ,american vertebrate paleontology has arisen to so high a plane1 when one considers the material at its disposal4 ,having a vast and virgin field for exploration1 a sufficient number of collectors1 some of whom have devoted much of their lives to the work1 and a refinement of technique that permitted the preservation of the fragmental and ill conserved as well as the finer specimens1 the results could hardly have been otherwise4 ,thus it has been possible to secure material almost unique throughout the world for extent1 for completeness1 and for variety4 ,to this must be added a certain ,american daring in the matter of the restoration of missing portions1 both of the individual bones and of the skeleton as a whole1 such as ,european conservatism will not as a rule permit4 ,this work has for the most part been done after the most painstaking comparison and research and is highly justified in the accuracy of the results1 which render the fabric of the skeleton much more intelligible1 both to the scientist and to the layman4 ,material once secured and prepared is then mounted1 and here again ,american ingenuity has accomplished some remarkable results4 ,some of the specimens thus mounted are so small and delicate as to require holding devices comparable to those for the display of jewels2 yet others--huge dinosaurs the bones of which are enormously heavy1 but so brittle that they will not bear even the weight of a process unsupported--require a carefully designed and skilfully worked out series of supports of steel or iron which must be perfectly secure and at the same time as inconspicuous as possible4 ,and of late the lifelike pose of the individual skeleton has been augmented by the preparation of groups of several animals which collectively exhibit sex1 size1 or other individual variations and the full mechanics of the skeleton under the varying poses assumed by the creature during life4 ,the work of further restoration has been rendered possible through comparative anatomical study1 enabling us to essay restorations in entirety by means of models and drawings1 clothing the bones with sinews and with flesh and the flesh with skin and hair1 if such the creature bore2 while the laws of faunal coloration have permitted the coloring of the restoration in a way which if not the actual hue of life is a very reasonable possibility4 ,thus the ,american paleontologists have blazed a trail which has been followed to good effect by certain of their ,old ,world colleagues4 ,with such means and methods and such material available1 it is again not surprising that ,american paleontology has furnished more and more of the evidences of evolution1 and disclosed to the eyes of scientists animal relationships which were undreamed of by the systematist whose research dealt only with the existing4 ,it has also explained some vexatious problems of animal distribution and of extinction1 and has connected up cause and effect in the great evolutionary movements which are recorded4 ,the results of systematic research have added hosts of new genera and species and of families1 but of orders there are relatively few4 ,nevertheless a number1 especially among reptiles and mammals1 have come to light as the fruits of ,american discovery4 ,but aside from the dry cataloguing of such groups1 the ,american systematists have worked out some very remarkable phylogenies and have thus clarified our vision of animal relationships in a way which the recent zoologist could never have done4 ,in this connection1 the ,permian vertebrates1 which have been collected and studied with amazing success1 principally by ,williston and ,case1 should be mentioned1 although the work is yet incomplete4 ,some of these forms are amphibian1 others reptilian1 yet others of such character as to link the two classes as transitional forms4 ,of the ,mesozoic reptiles1 a very remarkable assemblage has come to light1 in a degree of perfection unknown elsewhere4 ,these are dinosaurs1 of which several phyla are now known2 carnivores both great and small1 some of the latter being actually toothless2 ,sauropoda1 whose perfection and dimensions are incomparable except for those found in ,east ,africa2 and predentates1 armored1 unarmored1 and horned1 the last exclusively ,american4 ,the unarmored trachodonts are now known in their entirety1 for not only has our ,west produced articulated skeletons but mummified carcasses whose skin and other portions of their soft anatomy are represented1 and which are thus far without a parallel elsewhere in the world4 ,other reptilian groups are well known1 notably the ,triassic ichthyosaurs1 and the mosasaurs and plesiosaurs of the ,kansas chalk4 ,the last formation has also produced toothed birds1 ,hesperornis and ,ichthyornis1 which again are absolutely unique4 ,but it is in the mammalian class that the phylogenies become so highly complete and of such great importance as evolutionary evidences1 for nowhere else than in our own ,west have such series been found as the ,dinocerata and creodonts among archaic forms1 the primitive primates from the ,eocene1 the carnivores such as the dogs and cats and mustellids1 but especially the hoofed orders such as the horses4 ,of these hoofed orders1 the classic ,american series of horses is complete1 that of the camels probably no less so1 while much is known of the deer and oreodonts1 the last showing several parallel phyla1 and of the proboscideans1 which while having their pristine home in the ,old ,world nevertheless soon sought the new where their remains are found from the ,miocene until their final and apparently very recent extinction4 ,these creatures show increase of bulk1 perfection of feet and teeth1 development of various weapons1 horns and antlers1 which may be studied in their relationship with the other organs to make the evolving whole1 or their evolution may be traced as individual structures which have their rise1 culmination1 and sometimes their senile atrophy in a way comparable to that of the representatives of the order as a whole4 ,thus1 for example1 ,osborn has traced the evolution of the molar teeth1 and ,cope of the feet1 while ,marsh has shown that brain development runs a similar course and that its degree of perfection within a group is a potent factor for survival4 ,as a student of evolution1 the paleontologist sees things in a very different light from the zoologist4 ,the latter is concerned largely with matters of detail--with the inheritance of color or of the minor and more superficial characteristics of animals--and the period of observation of such phenomena is of necessity brief because of the mortality of the observer4 ,whereas the paleontologist has a perspective which the other lacks1 since for him time means little in the terms of his own life1 and he can look into the past and see the great and fundamental changes which evolution has wrought1 the rise of phyla1 of classes1 of orders1 and he alone can see the orderliness of the process and sense the majesty of the laws which govern it4 ,influence of the ,american ,journal of ,science4 ,the influence of the ,american ,journal of ,science as a medium for the dissemination of the results of vertebrate research has been in evidence throughout this discussion1 but it were well1 perhaps1 to emphasize that service more fully4 ,the ,journal was1 as we have seen1 the chief outlet for ,professor ,marsh's research1 for there were published in it during his lifetime no fewer than #age papers descriptive of the forms which he studied1 as well as a great part of the material in the published monographs4 ,as ,marsh left very few manuscript notes1 the importance of these frequent publications in thus setting forth much that he thought and learned concerning the material is very great indeed4 ,the combined titles of all other authors in the ,journal in this line of research for the century of its life fall far short of the number produced by ,marsh alone1 as they include #acf all told1 but the range of subjects is highly representative of the entire field of vertebrate research4 ,it should be borne in mind1 moreover1 that ,leidy1 ,cope1 and ,osborn each had another medium of publication1 which of course is true of other workers in the great museums such as the ,american1 ,national1 and ,carnegie1 all of which issue bulletins and quarto publications for the purpose of disseminating the work of their staff4 ,many of the earlier announcements of the discovery of vertebrate relics appeared in the ,journal1 as did practically all the literature of the science of fossil footprints 7ichnology71 except of course the larger quartos of ,hitchcock and ,deane4 ,of the footprint papers by ,hitchcock1 ,deane1 and others1 there were no fewer than thirty-two1 with a number of additional communications on attendant phenomena bones and plants4 ,up to #ahdg1 except for a few foreign announcements1 the ,journal published almost exclusively on eastern ,american paleontology1 the only exception being a notice of bones from ,oregon by ,perkins in #ahdb4 ,in #ahdg came the announcement of a western 8,palothere0 by ,prout1 which marked the beginning of the researches of ,leidy and others in the ,bad ,lands of the great ,nebraska plains4 ,the ,journal thenceforth published paper after paper on forms from all over ,north ,america1 and on all aspects of our science3 discovery1 systematic description1 faunal relationships1 evolutionary evidences--thus showing that breadth and catholicity which has made it so great a power in the advancement of science4 ,,vii ,,the ,,rise ,,of ,,petrology ,,as ,a ,,science ,by ,,louis ,v4 ,,pirsson ,this chapter is intended to present a brief sketch of the progress of the science of petrology from its early beginnings down to the present time4 ,the field to be covered is so large that this can be done only in broadest outline1 and it has therefore been restricted chiefly to what has been accomplished in ,america4 ,although the period covered by the life of the ,journal extends backward for a century it is1 however1 practically only within the last fifty years that the rocks of the earth's crust have been made the subject of such systematic investigation by minute and delicately accurate methods of research as to give rise to a distinct branch of geologic science4 ,it is not intended of course to affirm by this statement that the broader features of the rocks1 especially those which may be observed in the field and which concern their relations as geologic masses1 had not been made the object of inquiry before this time1 since this is the very foundation of geology itself4 ,moreover1 a certain amount of investigation of rocks1 as to the minerals of which they were composed1 the significance of their textures1 and their chemical composition1 had been carried out1 concomitant with the growth from early times of geology and mineralogy4 ,thus1 in #ahae1 ,cordier by a process of washing separated the components of a basalt and by chemical tests determined the constituent minerals4 ,at the time the ,journal was founded1 and for many years following1 the genesis of rocks1 especially of igneous rocks1 was a subject of inquiry and of prolonged discussion4 ,the aid of the rapidly growing science of chemistry was invoked by the geologists and analyses of rocks were made in the attempt to throw light on important questions4 ,it is remarkable1 also1 how keen were the observations that the geologists of those days made upon the rocks1 as to their component minerals and structures1 aided only by the pocket lens4 ,many ideas were put forward1 the essentials of which have persisted to the present day and have become interwoven into the science1 whereas others gave rise to contentions which have not yet been settled to the satisfaction of all4 ,at times in these earlier days the microscope was called into use to help in solving questions regarding the finer grained rocks1 but this employment1 as ,zirkel has shown1 was merely incidental1 and no definite technique or purpose for the instrument was established4 ,on the other hand1 the fact that up to the middle of the last century a large store of information relating to the occurrence of rocks1 and to the mineral composition of those of coarser grain1 and somewhat in respect to their structure1 had been accumulated1 caused attempts in one way or another to find means of cordinating these data and to produce classifications1 such as those of ,von ,cotta and ,cordier4 ,the history of these attempts at classification1 before the revelations made by the use of the microscope had become general1 has been admirably reviewed by ,whitman ,cross#ajg and need not be further enlarged upon here4 ,that a considerable amount of work was done along chemical lines also is testified to by the publication of ,roth's ,tabellen in #ahfa1 in which all published analyses of rocks up to that date were collected4 ,what was accomplished during this period was done chiefly on the continent of ,europe1 and little attention had been paid to the subject of rocks either in ,america or in ,great ,britain--even so late as #ahgj ,geikie remarks1 as referred to by ,cross1#ajh that there was no good ,english treatise on petrography1 or the classification and description of rocks4 ,in this country still less had been accomplished1 interest being almost wholly confined to the vigorous and growing sciences of geology and mineralogy4 ,this was natural1 for mineralogy is the chief buttress on which the structure of petrology rests and must naturally develop first1 especially in a relatively new and unexplored region1 whose mineral resources first attract attention4 ,the geologists in carrying out their studies also observed the rocks as they saw them in the field and made incidental reference to them1 but investigations of the rocks themselves was very little attempted4 ,an inspection of the first two series of the ,journal shows relatively little of importance in petrology published in this country2 a few analyses of rocks1 occasional mention of mineral composition1 of weathering properties1 and notices of methods of classification proposed by ,french and ,german geologists nearly exhaust the list4 ,introduction of the ,microscope4 ,the beginnings of a particular branch of science are generally obscure and rooted so imperceptibly in the foundations on which it rests that it is difficult to point to any particular place in its development and say that this is the start4 ,there are exceptions of course1 like the remarkable work of ,willard ,gibbs in physical chemistry1 and it may chance that the happy inspiration of a single worker may give such direction to methods of investigation as to open the gates into a whole new realm of research1 and to thus create a separate scientific field1 as happened in ,radiochemistry4 ,this is what occurred in petrology when ,sorby in ,england1 in #aheh1aji pointed out the value of the microscope as an instrument of research in geologic investigations1 and demonstrated that its employment in the study of thin sections of rocks would yield information of the highest value4 ,others beside ,sorby had made use of the microscope1 as pointed out by ,zirkel1#aaj but1 as he indicates1 no one before him had recognized its value4 ,during the next ten years or so1 however1 its recognition was very slow and the papers published by ,sorby himself were mainly concerned in settling very special matters4 ,as ,williams#aaa has suggested1 the greatest service of ,sorby was1 perhaps1 his instructing ,zirkel in his ideas and methods1 for the latter threw himself whole-heartedly into the study of rocks by the aid of the microscope and his discoveries stimulated other workers in this field in ,germany1 his native country1 until the dawning science of petrology began to assume form4 ,a further step forward was taken in #ahgc in the appearance of the text-books of ,zirkel#aab and ,rosenbusch#aac which collated the knowledge which had been gained and furnished the investigator more precise methods of work4 ,it is difficult for the student of to-day to realize how much had been learned in the interval and1 for that matter1 how much has been gained since #ahgc1 without an inspection of these now obsolete texts4 ,in #ahfc1 ,zirkel1 who was then at the beginning of his work1 said in his first paper presented to the ,vienna ,academy of ,sciences#aad that if he confined himself chiefly to the structure of the rocks investigated and of their component minerals1 and stated little as to what these minerals were1 the reason for that was because 8although the microscope serves splendidly for the investigation of the former relations1 it promises very little help for the latter4 ,labradorite1 oligoclase and orthoclase1 augite and hornblende1 minerals whose recognition offers the most important problems in petrography1 in most cases cannot be distinguished from one another under the microscope40 ,how little could ,zirkel have foreseen1 at this time1 less than forty years later1 that not only could labradorite be accurately determined in a rock-section1 but that in a few minutes by the making of two or three measurements on a properly selected section1 its chemical composition and the crystallographic orientation of the section itself could be determined6 ,the ,thin ,section4 ,before going further we may pause here a moment to consider the origin and development of the thin section1 without which no progress could have been made in this field of research4 ,when we reflect upon the matter1 it seems a marvelous thing indeed that the densest1 blackest rock can be made to yield a section of the of an inch in thickness1 so thin and transparent that fine printing can be easily read through it1 and transmitting light so clearly that the most high-powered objectives of the microscope can be used to discern and study the minutest structures it presents with the same capacity that they can be employed upon sections of organic material prepared by the microtome4 ,this is no small achievement4 ,the first thin sections appear to have been prepared in #ahbh by ,william ,nicol of ,edinburgh1 to whom we owe the prism which carries his name4 ,he undertook the making of sections from fossil wood for the purpose of studying its structure4 ,the method he developed was in principle the same as that employed to-day1 where machinery is not used2 that is1 he ground a flat smooth surface upon one side of a chip of his petrified wood1 then cemented this to a bit of glass plate with ,canada balsam1 and ground down the other side until the section was sufficiently thin4 ,this method was used by others for the study of fossil woods1 coal1 etc41 but it was not applied to rocks until #ahej1 when ,sorby used it for investigating a calcareous grit4 ,oschatz1 in ,germany1 also about this time independently discovered the same method4 ,a further advance was made in melting the cement1 floating off the slice1 and transferring it to a suitable object-glass with cover1 a process still employed by many2 though most operators now cement the first prepared surface of the rock chip directly to the object-glass1 and mount the section without transferring it4 ,next came the use of machinery to save labor in grinding1 and another step was made in the introduction of the saw1 a circular disk of sheet iron whose edge was furnished with embedded diamond dust4 ,this makes it possible to cut relatively thin slices with comparative rapidity1 but the final grinding which requires experience and skill must still be done by hand4 ,carborundum has also largely replaced emery4 ,the skill and technique of preparers has reached a point where sections of rocks of the desired thinness 7#jjja inch71 and four or five inches square have been exhibited4 ,the ,era of ,petrography4 ,in these earlier days of the science1 as noted above1 great difficulty was at first experienced in the recognition of the minerals as they were encountered in the study of rocks under the microscope4 ,at that time the chemical composition and outward crystal form of minerals were relatively much better known than their physical and1 especially1 their optical properties and constants4 ,some beginnings in this had been made by ,brewster1 ,nicol1 and other physicists1 and the mineralogists had commenced to study minerals from this viewpoint4 ,especially ,des ,cloiseaux had devoted himself to determining the optical properties of many minerals1 and the writer1 when a student in the laboratory of ,rosenbusch in #ahij1 well recalls the tribute that he paid to the work of ,des ,cloiseaux for the aid which it had afforded him in his earlier researches in petrography4 ,the twenty years following the publication of the texts of ,rosenbusch and ,zirkel may be characterized as the era of microscopical petrography4 ,a distinction is drawn here between the latter word and petrology1 a distinction often overlooked1 for petrography means literally the description of rocks1 whereas petrology denotes the science of rocks4 ,as time passed the broader and more fundamental features of rocks1 especially of igneous and metamorphic rocks1 in addition to their mineral constitution1 were more studied and gained greater recognition1 petrography gradually became a department of the larger field of petrology--the science of to-day4 ,the use of the microscope1 as soon as the method became more generally understood1 opened up so vast a field for investigation that at first the study and description of the rocks seemed of prime importance4 ,this was natural1 for hitherto the finer grained rocks had for the most part defied any adequate elucidation and here was a key which enabled one to read the cipher4 ,a flood of literature upon the composition1 structure1 and other characters of rocks from all parts of the world began to appear in ever increasing volume4 ,the demands of the petrographers for a greater and more accurate knowledge of the physical and optical constants of minerals stimulated this side of mineralogy1 and increasing attention was given to investigations in this direction4 ,no definite line between the two closely related sciences could be drawn1 and a large part of the work published under the heading of petrography could perhaps be as well1 or better1 described under the title of micro-mineralogy4 ,to some1 in truth1 the rocks presented themselves simply as aggregates of minerals1 occurring in fine grains4 ,the work of the ,german petrographers attracted attention and drew students from all parts of the world to their laboratories1 especially to those of ,zirkel and ,rosenbusch4 ,the great opportunities1 facilities1 and freedom for work which the ,german universities had long offered to foreign students of science naturally encouraged this4 ,in ,france a brilliant school of petrologists1 under the able leadership of ,michel-,lvy and ,fouqu1 had arisen whose work has been continued by ,barrois1 ,lacroix and others1 but the rigid structure of the ,french universities at that period did not permit of the offering of great inducements for the attendance of foreign students4 ,the work of the ,french petrographers will be noticed in another connection4 ,in ,great ,britain1 the home of ,sorby1 the new science progressed at first slowly1 until it was taken up by ,allport1 ,bonney1 ,judd1 ,rutley1 and others4 ,in #ahhe the evidence of the advance that had been made and of the firm basis on which the new science was now placed appeared in ,teall's great work1 8,british ,petrography10 which marked an epoch in that country in petrographic publication4 ,this work was of importance also in another direction than that of descriptive petrography1 in that it contains valuable suggestions for the application of the principles of modern physical chemistry in solving the problems of the origin of igneous rocks4 ,in it1 as in the publications of ,lagorio1 we see the passage of the petrographic into the petrologic phase of the science4 ,the earliest publication in ,america of the results of microscopic investigation of rocks that the writer has been able to find is by ,a4 ,a4 ,julien and ,c4 ,e4 ,wright1 chiefly on greenstones and chloritic schists from the iron-bearing regions of upper ,michigan4#aae ,naturally1 it was of a brief and elementary character4 ,in #ahgd ,e4 ,s4 ,dana read a paper before the ,american ,association for the ,advancement of ,science on the result of his studies on the 8,trap-rocks of the ,connecticut valley10 an abstract of which was published in this ,journal4#aaf ,meanwhile ,clarence ,king1 in charge of the #djth ,parallel survey1 feeling the need of a systematic study of the crystalline rocks which had been encountered1 and finding no one in this country prepared to undertake it1 had induced ,zirkel to give his attention to this task4 ,the result of this labor appeared in #ahgf in a fine volume#aag which attracted great attention4 ,in the same year appeared also petrographical papers by ,j4 ,h4 ,caswell1#aah ,e4 ,s4 ,dana#aai and ,g4 ,w4 ,hawes4#abj ,the latter devoted himself almost entirely to this field of research and may thus1 perhaps1 be termed the earliest of the petrographers in this country4 ,his work1 8,the ,mineralogy and ,lithology of ,new ,hampshire10 issued in #ahgh as one of the reports of the ,state ,survey under ,prof4 ,c4 ,h4 ,hitchcock1 was the first considerable memoir by an ,american4 ,this was followed by various papers1 one on the 8,albany ,granite and its contact phenomena10#aba being of especial interest as one of the earliest studies of a contact zone1 and in the fullness of methods employed in attacking the problem forecasting the change to the petrology era4 ,during the ten years following1 or from #ahhj to #ahij1 the new science of petrography flourished and grew exceedingly4 ,many young geologists abroad devoted themselves to this field of research and the store of accumulated knowledge concerning rocks from all parts of the world1 and their relations grew apace4 ,the work of ,teall has been noticed and among others might be mentioned the name of ,brgger1 whose first contribution#abb in this field gave evidence that his publications would become classics in the science4 ,in ,america there appeared in this period a number of eager workers1 trained in part in the laboratories of ,rosenbusch and ,zirkel1 whose researches were destined to place the science on the secure footing in this country which it occupies to-day4 ,among the earlier of these may be mentioned ,whitman ,cross1 ,r4 ,d4 ,irving1 ,j4 ,p4 ,iddings1 ,g4 ,h4 ,williams1 ,j4 ,f4 ,kemp1 ,j4 ,s4 ,diller1 ,b4 ,k4 ,emerson1 ,m4 ,e4 ,wadsworth1 ,g4 ,p4 ,merrill1 ,n4 ,h4 ,winchell1 and ,f4 ,d4 ,adams in ,canada4 ,others were added yearly to this group4 ,as a result of their work a constantly growing volume of information about the rocks of ,america became available1 and one has only to examine the files of the ,journal and other periodicals and the listed publications of the ,national and ,state ,surveys to appreciate this4 ,in the ,journal1 for example1 we may refer to papers#abc by ,emerson on the ,deerfield dike and its minerals1 and on the occurrence of nephelite syenite at ,beemersville1 ,n4 ,j42 to various interesting articles by ,cross on lavas from ,colorado and the pneumatolytic and other minerals associated with them2 to important papers by ,iddings on the rocks of the volcanoes of the ,northwest1 and those of the ,great ,basin1 to primary quartz in basalt1 and the origin of lithophys2 to the results of researches by ,g4 ,h4 ,williams on the rocks of the ,cortlandt series1 and on peridotite near ,syracuse1 ,n4 ,y42 to papers by ,diller on the peridotites of ,kentucky1 and recent volcanic eruptions in ,california2 to articles by ,r4 ,d4 ,irving on the copper-bearing and other rocks of the ,lake ,superior region1 and to ,kemp on dikes and other eruptives in southern ,new ,york and northern ,new ,jersey4 ,other publications would greatly extend this list4 ,the ,petrologic ,era4 ,as the chief facts regarding rocks1 especially igneous rocks1 as to their mineral and chemical composition1 their structure and texture and the limits within which these are enclosed1 became better known2 and the relations1 which these bear to the associations of rocks and their modes of occurrence1 began to be perceived1 the science assumed a broader aspect4 ,the perception that rocks were no longer to be regarded merely as interesting assemblages of minerals1 but as entities whose characters and associations had a meaning1 increased4 ,more and better rock analyses stimulated interest on the chemical side and this and the genesis of their minerals led to a consideration of the magmas and their functions in rock-making4 ,the fact that the different kinds of rocks were not scattered indiscriminately1 but that different regions exhibited certain groupings with common characters1 was noticed4 ,these features led to attempts to classify igneous rocks on different lines from those hitherto employed1 and to account for their origin on broad principles4 ,in other words1 the descriptive science of petrography merged into the broader one of petrology4 ,no exact time can be set which marks this passage1 since the evolution was gradual4 ,yet for this country1 in reviewing the literature1 for which the successive issues of the 8,bibliography of ,north ,american ,geology0 published by the ,u4 ,s4 ,geological ,survey has been of the greatest value2 the writer has been struck by the fact that in the first volume containing the index of papers down to and including #ahia1 the articles on subjects of this nature are listed under the heading of petrography1 whereas in the second volume 7#ahib-aijj7 they are grouped under petrology and the former heading is omitted4 ,a justification for this is found in examining the list of publications and noting their character4 ,with some reason1 therefore1 the beginning of this period may be placed as in the early years of this decade4 ,furthermore1 it was at this time that the great work of ,zirkel#abd began to appear1 which sums up so completely the results of the petrographic era4 ,rosenbusch#abe was formulating more definitely his views on the division of rocks into magmatic groups1 as displayed by their associations in the field1 and using this in classification2 an idea which1 appearing first in the second edition of his 8,physiographie der massigen ,gesteine10 finds fuller development in the third and last editions of this work4 ,in this country ,iddings#abf published an important paper1 in which the family relationships of igneous rocks and the derivation of diverse groups from a common magma by differentiation are clearly brought out4 ,the fundamental problems underlying the genesis of igneous rocks had now been clearly recognized1 and with this recognition the science passed into the petrologic phase4 ,brgger#abg also had ascribed to the alkalic rocks of ,south ,norway a common parentage and had pointed out their regional peculiarities4 ,from this time forward an attempt may be noted to find an analogy between rocks and the forms of organic life and to apply those principles of evolution and descent1 which have proved so fruitful in the advancement of the biological sciences1 to the genesis and classification of igneous rocks4 ,this1 perhaps1 has on the whole been more apparent than real1 in the constant borrowing of terms from those sciences to express certain features and relationships observed1 or imagined1 to obtain among rocks4 ,nevertheless1 the perception of certain relations which we owe so largely to ,rosenbusch and to ,brgger#abh has proved of undoubted value in furnishing a stimulus for the investigation of new regions1 and in affording indications of what the petrologist should anticipate in his work4 ,thus1 the labors of the men previously mentioned1 with those of ,bayley1 ,bascom1 ,cushing1 ,daly1 ,lane1 ,lawson1 ,lindgren1 ,pirsson1 ,j4 ,f4 ,williams1 ,washington1 and others1 have thrown a flood of light upon the igneous rocks of this continent1 and has made it possible to draw many broad generalizations concerning their origin and distribution4 ,thus1 the differentiated laccoliths of ,montana#abi have been of service in affording clear examples of the process of local differentiation4 ,many papers published in the ,journal during the last twenty years show this evolution and growth of petrological ideas4 ,the contributions from ,american sources during this later period1 and of which those in the ,journal form a considerable fraction1 have indeed been of great weight in shaping the development and future of the science4 ,by referring to the files of the ,journal1 it will be seen that they cover a continually widening range of subjects concerning rocks1 and articles of theoretical interest are more and more in evidence1 along with those of a purely descriptive character4#acj ,thus we find discussions by ,becker on the physical constants of rocks1 on fractional crystallization1 and on differentiation2 by ,cross on classification2 by ,adams on the physical properties of rocks2 by ,daly on the methods of igneous intrusion2 by ,wright on schistosity2 by ,fenner on the crystallization of basaltic magma2 by ,bowen on differentiation by crystallization2 by the writer on complementary rocks and on the origin of phenocrysts2 by ,smyth on the origin of alkalic rocks2 by ,murgoci on the genesis of riebeckite rocks2 and by ,barrell on contact-metamorphism4 ,these may serve as examples1 selected almost at random1 from the files of the ,journal1 and we find with them articles descriptive of the petrology of many particular regions1 which often contain also matter of general interest and importance1 such as papers by ,lindgren on the granodiorite and related rocks of the ,sierra ,nevada2 by ,ransome on latite2 by ,cross on the ,leucite ,hills2 by ,hague on the lavas of the ,yellowstone ,park2 by ,pogue on ancient volcanic rocks from ,north ,carolina2 by ,warren on peridotites from ,cumberland1 ,r4 ,i42 on sandstone from ,texas by ,goldman2 and on the petrology of various localities in central ,new ,hampshire by ,washington and the writer4 ,such a list could of course be much extended and other papers of importance be cited1 but enough has been said to indicate how important a repository of the results of petrologic research the ,journal has been and continues to be4 ,in thus looking backward over the list of active workers we are involuntarily led to pause and reflect how great a loss ,american petrology has sustained in the premature death of some of its most brilliant and promising exponents2 it is only necessary to recall the names of ,r4 ,d4 ,irving1 ,g4 ,h4 ,williams1 ,g4 ,w4 ,hawes1 ,j4 ,f4 ,williams and ,carville ,lewis1 to appreciate this4 ,the store of material gathered during these years has led to the publication of extensive memoirs1 in which the science is treated not from the older descriptive side1 but from the theoretical standpoint and of classification4#aca ,in these works strong divergencies of views and opinions are observed1 which is a healthy sign in a developing science4 ,it should be also noted that along with this evolution on the theoretical side there has been a constant improvement in the technique of investigating rocks4 ,it is only necessary to compare the older handbooks of ,zirkel and ,rosenbusch with the many modern treatises on petrographic methods to be assured of this4#acb ,it is due on the one hand to the vast amount of careful work which has been done in accurately determining the physical constants of rock-minerals#acc and in arranging these for their determination microscopically1 as in the remarkable studies on the feldspars by ,michel-,lvy1 and on the other in researches on the apparatus employed1 and in consequent improvements in them and in ways of using them1 as exemplified in the delicately accurate methods introduced by ,wright4#acd ,the development of the microscope itself as an instrument of research in this field and in mineralogy deserves a further word in this connection4 ,the first step toward making the ordinary microscope of special use in this way was taken by ,henry ,fox ,talbot of ,england1 when he introduced in #ahcd the employment of the recently invented nicol prisms for testing objects in polarized light4 ,the modern instrument may be said to date from the design offered by ,rosenbusch in #ahgf4 ,since that time there have been constant improvements1 almost year by year1 until the instrument has become one of great precision and convenience1 remarkably well adapted for the work it is called upon to perform1 with special designs for various kinds of use1 and an almost endless number of accessory appliances for research in different branches of mineralogy and crystallography1 as well as in petrography proper4#ace ,this also calls to mind the fact that for the convenience of those who are not able to use the microscope special manuals of petrology have been prepared in which rocks are treated from the megascopic standpoint4#acf ,metamorphic ,rocks4 ,in this connection the metamorphic rocks should not be forgotten4 ,they afford indeed the most difficult problems with which the geologist has to deal2 every branch of geological science may in turn be called upon to furnish its quota for help in solving them4 ,under the attack of careful1 accurate and persistent work in the field1 under the microscope and in the chemical laboratory1 with the aid of the garnered knowledge in petrology1 stratigraphy1 physiography1 and other fields of geologic science1 their mystery has in large part given way4 ,the inaugural work of ,lehmann1 ,lossen1 ,barrois1 ,bonney1 ,teall1 and other ,european geologists1 was paralleled in ,america by that of ,r4 ,d4 ,irving1 owing to whose efforts the ,lake ,superior region became the chief place of study of the metamorphic rocks in this country4 ,irving soon obtained the assistance of ,g4 ,h4 ,williams1 who had been engaged in the study of such rocks1 and the latter published a memoir on the greenstone schist areas of ,menominee and ,marquette in ,michigan#acg which will always remain one of the classics in the literature of metamorphic rocks4 ,irving's own contributions to petrology1 though valuable1 were cut short by his untimely death1 but the study of this region under the direction of his associate and successor1 ,c4 ,r4 ,van ,hise1 with his co-laborers1 has yielded a mass of information of fundamental importance in our understanding of metamorphism and the crystalline schists4 ,its fruitage appears in the memoir by ,van ,hise#ach which is the authoritative work of reference on metamorphism1 and in various publications by him and his assistants1 ,bayley1 ,clements1 ,leith1 and others4 ,the work of the ,canadian geologists1 and of ,kemp1 ,cushing1 ,smyth and ,miller in the ,adirondack region1 should also be mentioned in connection with this field of petrology4 ,chemical ,analyses of ,rocks4 ,it has been previously pointed out that1 as the science of petrology grew1 chemical investigations of rocks in bulk were undertaken4 ,the object of such analyses was to obtain on the one hand a better control over the mineral composition and on the other to gain an idea of the nature of the magmas from which igneous rocks had formed4 ,the earliest analysis of an ,american rock of which ,i can find record is of a 8wacke0 by ,j4 ,w4 ,webster given in the first volume of the ,journal1 page #bif1 #ahah4 ,during the next #dj years a few occasional analyses were undertaken by ,american chemists1 by ,c4 ,t4 ,jackson1 ,t4 ,sterry ,hunt1 and others4 ,in #ahfa1 ,justus ,roth published the first edition of his ,tabellen1 in which he included all analyses which had been made to that date and which he considered were worthy of preservation4 ,although1 naturally1 from the status of analytical chemistry up to that time1 most of these would now be considered rather crude1 the publication of the work was of great service and marked an epoch in geochemistry4 ,in these tables ,roth lists four analyses of ,american igneous rocks1 two from the ,lake ,superior region by ,jackson and ,j4 ,d4 ,whitney and two by ,european chemists1 one of whom was ,bunsen4 ,the material of the last two was a 8dolerite0 and the same locality is given for each--8,sierra ,nevada between #ch and #da0 which was probably considered quite precise for western ,america in those days4 ,from these feeble beginnings the forward progress of petrology on the chemical side in this country has been a steady one until its development has reached the point which will be indicated in what follows4 ,the collection of material by the various ,state surveys and by those initiated by the ,national ,government led to an increasing number of rocks being analyzed during the petrographic period4 ,these became also increasingly good in quality1 like those published by ,g4 ,w4 ,hawes in his papers4 ,when1 however1 chemists were appointed to definite positions on the staffs of the ,government surveys and especially when1 after the organization of the ,u4 ,s4 ,geological ,survey in #ahgi1 a general central laboratory was founded in #ahhc with ,f4 ,w4 ,clarke in charge1 then a new era in the chemical investigation of rocks may be said to have started4 ,in this connection should be mentioned the work of ,w4 ,f4 ,hillebrand1 who set a standard of accuracy and detail in rock analysis which had not hitherto been attempted4 ,as a consequence of his accurate and thorough methods and results the mass of analyses performed by him and his fellow chemists in this laboratory affords us the greatest single contribution to chemical petrology which has been made4 ,up to ,january1 #aiad1 the report of ,clarke#aci lists some #hjjj analyses of various kinds made in this laboratory for geologic purposes4 ,nearly everywhere also a great improvement in the quality of rock-analyses is to be noted1 and in the manuals of ,hillebrand#adj and ,washington#ada the rock analyst has now at his command the methods of a greatly perfected technique which should insure him the best results4 ,roth's ,tabellen have been previously mentioned2 several supplements were published1 but after his death a long interval elapsed before this convenient and useful work was again taken up by ,washington#adb and ,osann4#adc ,a new edition of ,washington's ,tables has recently been published1 listing some #hfjj analyses of igneous rocks made up to the close of #aiac4add ,on the theoretical side also1 where petrology passes into geology1 the investigator of to-day will find a mass of most useful and accurate data well discussed in the modern representative of ,bischof's ,chemical ,geology--,clarke's ,data of ,geochemistry4#ade ,the advance on the chemical side1 therefore1 has been quite commensurate with that in the microscope as an instrument1 and in the results obtained by it4 ,physico-,chemical ,work4 ,the study of geological results by experimental methods1 which should gain information concerning the processes by which those results are caused1 and the conditions under which they operate1 has been from the earliest days of the developing science recognized as most important1 and the record of the literature shows considerable was done in this direction4 ,experimental work in modern petrology may1 however1 be considered to date from #ahhb when ,fouqu and ,michel-,lvy#adf published the results of their extensive researches on the synthesis of minerals and rocks by pyrogenous methods4 ,the brilliant experiments of the ,french petrologists at once attracted attention1 and since that time a considerable volume of valuable work has been done in this field by a number of men1 among whom may be mentioned ,morozewicz1#adg ,doelter1#adh ,tamman1#adi and ,meunier4#aej ,as this work continued the results of the rapid advances made in physical chemistry began to be applied in this field with increasing value4 ,to ,j4 ,h4 ,l4 ,vogt we owe a valuable series of papers1#aea in which the formation of minerals and rocks from magmas is treated from this standpoint4 ,most important of all for the future of petrology has been the founding in ,washington of the splendid research institution1 the ,carnegie ,geophysical ,laboratory1 under the leadership of ,dr4 ,a4 ,l4 ,day with its corps of trained physicists1 chemists and petrologists1 devoted to the solving of the problems which the progress of geological science raises4 ,the publications of this institution 7many of them published in the ,journal7 are too numerous to be mentioned here2 many of them treat successfully of matters of the greatest importance in petrology4 ,this is an earnest of what we may hope in the future4 ,the accumulation of the exact physical and chemical data1 which is its aim1 will serve as a necessary check to hypothetical speculation and bring petrology1 and especially petrogenesis1 in line with the other more exact sciences by furnishing quantitative foundations for its structure of theory to rest upon4 ,while the achievements of this great organization seem to minimize the work of the individual investigator in this field1 he may take heart by observing the important results on the strength of rocks under various conditions which have been obtained by ,adams in recent years1 data of wide application in theoretical geology4 ,in this field also a special text has appeared in which the principles and acquired data are given4#aeb ,summary4 ,in this brief retrospect1 giving only the barest outlines and omitting from necessity much of importance1 we have seen petrology grow from occasional crude experiments into a fully organized science in the last half century4 ,it has to-day a well-perfected technique1 a large volume of literature1 texts treating of general principles1 of methods of work1 descriptive handbooks on the morphological side1 and has attained general recognition as a field1 which1 though not large1 is worthy of the concentration of intellectual endeavor4 ,like other healthy growing organisms it has given rise to offshoots1 and the sciences of metallography and of the micro-study of ore deposits1 which are rapidly assuming form1 have branched from it4 ,what of the future8 ,the old days of mostly descriptive work1 and of theorizing purely from observed results1 have passed4 ,the science has entered upon the stage where work and theory must be continually brought into agreement with chemical1 physical and mathematical laws and data1 and in the application of these new problems present themselves4 ,as we climb1 in fact1 new horizons open to our view indicating fresh regions for exploration1 for acquiring human knowledge and for our satisfaction4 ,bibliography4 ,footnote #ajg3 ,w4 ,cross1 ,jour4 ,geology1 #aj1 #dea1 #aijb4 ,footnote #ajh3 ,ibid41 p4 #de4 ,footnote #aji3 ,sorby1 ,quart4 ,jour4 ,geol4 ,soc41 #ad1 #dec1 #aheh4 ,footnote #aaj3 ,zirkel1 ,einfhrung des ,mikroskops in das mineralogisch-geologische ,studium1 #ahha4 ,footnote #aaa3 ,williams1 ,g4 ,h41 ,modern ,petrography1 #ahhf4 ,footnote #aab3 ,zirkel1 ,mikroskopische ,beschaffenheit der ,mineralien und ,gesteine4 ,footnote #aac3 ,rosenbusch1 ,mikroskopische ,physiographie der petrographisch wichtigen ,mineralien4 ,footnote #aad3 ,zirkel1 ,mikroskopische ,gesteinstudien1 ,sitzung vom #ab ,mrz1 #ahfc4 ,footnote #aae3 ,julien and ,wright1 ,geol4 ,surv4 of ,michigan1 #b1 #ahgc4 ,appendices ,a and ,c4 ,footnote #aaf3 ,dana1 ,e4 ,s41 the ,journal1 #h1 #cij-cib1 #ahgd4 ,footnote #aag3 ,zirkel1 ,geological ,exploration of the #djth ,parallel2 vol4 ,,vi1 ,microscopical ,petrography4 ,footnote #aah3 ,caswell1 ,microscopical ,petrography of the ,black ,hills4 ,u4 ,s4 ,geog4 and ,geol4 ,surv4 ,rocky ,mts4 ,rep4 on ,black ,hills of ,dakota1 #dfi-ebg4 ,the separate copies issued bear the imprint #ahgf2 the complete report #ahhj4 ,footnote #aai3 ,dana1 ,e4 ,s41 ,igneous ,rocks in the ,judith ,mts4 ,rep4 of ,reconnaissance ,carroll1 ,mont41 to ,yellowstone ,park in #ahge4 ,col4 ,wm4 ,ludlow1 ,war ,dept41 ,washington1 #aje-ajf4 ,footnote #abj3 ,hawes1 ,g4 ,w41 ,rocks of the ,chlorite ,formation1 etc41 the ,journal1 #aa1 #abb-abf1 #ahgf4 ,greenstones of ,new ,hampshire1 etc1 ibid41 #ab1 #abi-acg1 #ahgf4 ,footnote #aba3 ,hawes1 ,g4 ,w41 the ,journal1 #ba1 #ba-cb1 #ahha4 ,footnote #abb3 ,brgger1 ,die silurischen ,etagen #b und #c1 ,kristiania1 #ahhb4 ,footnote #abc3 ,the references for the papers alluded to1 all of them in the ,journal1 are as follows3 ,emerson1 #bd1 #aie-bjb1 #bgj-bgh1 #cdi-cei1 #ahhb2 ----1 #bc1 #cjb-cjh1 #ahhb4 ,cross1 #bg1 #id-if1 #ahhd2 #ca1 #dcb-dch1 #ahhf2 #ci1 #cei-cgj1 #ahij2 #da1 #dff-dge1 #ahia2 #bc1 #deb-deh1 #ahhb4 ,iddings1 #bf1 #bbb-bce1 #ahhc2 ----1 #bg1 #dec-dfc1 #ahhd2 ----1 #cf1 #bjh-bba1 #ahhh2 ----1 #cc1 #cf-de1 #ahhg4 ,williams1 #ca1 #bf-da1 #ahhf2 #cc1 #ace-add1 #aia-aii1 #ahhg2 #ce1 #dcc-ddh1 #ahhh2 #cf1 #bed-bei1 #ahhh4 ----1 #cd1 #acg-ade1 #ahhg4 ,diller1 #cb1 #aba-abe1 #ahhf2 #cg1 #bai-bbj1 #ahhi2 ----1 #cc1 #de-ej1 #ahhg4 ,irving 7#bf1 #bg-cb1 #cba-cbb1 #bg1 #acj-acd1 #ahhc2 #bi1 #ceh-cei1 #ahhe74 ,kemp 7#ce1 #cca-ccb1 #ahhh2 #cf1 #bdg-bec1 #ahhh2 #ch1 #acj-acd1 #ahhi74 ,footnote #abd3 ,zirkel1 ,lehrbuch der ,petrographie1 #b;d ed41 #ahic4 ,footnote #abe3 ,hunter and ,rosenbusch1 ,ueber ,monchiquit1 etc41 ,min4 petr4 ,mitth41 #aa1 #dde1 #ahij4 ,rosenbusch1 ,ueber ,structur und ,class4 der ,eruptivgesteine1 ibid41 #ab1 #cea1 #ahia4 ,footnote #abf3 ,iddings1 ,origin of ,igneous ,rocks1 ,bull4 ,phil1 ,soc4 ,washington1 #ab1 #hi-bac1 #ahib4 ,footnote #abg3 ,brgger1 ,mineralien der ,syenit-pegmatit-gnge1 etc41 ,zs4 ,kryst41 #af1 #ahij4 ,footnote #abh3 ----1 ,basic ,eruptive ,rocks of ,gran1 ,quart4 ,jour4 ,geol4 ,soc41 #ej1 #ae1 #ahid2 ,grorudit-,tinguait-,serie1 ,vidensk4 ,skrift4 #a ,math4 nat4 ,kl41 ,no4 #d1 #ahid4 ,footnote #abi3 ,weed and ,pirsson1 e4 g4 ,shonkin ,sag1 the ,journal1 #ab1 #a-ag1 #aija4 ,footnote #acj3 ,the references for the articles mentioned 7all in the ,journal7 are as follows3 ,becker1 #df1 #ahic2 #d1 #beg1 #ahig2 #c1 #ba-dj1 #ahig4 ,cross1 #ci1 #feg-ffa1 #aiae4 ,adams1 #bb1 #ie-abc1 #aijf2 #bi1 #dfe-dhg1 #aiaj4 ,daly1 #bb1 #aie-baf1 #aijf2 #bf1 #ag-ej1 #aijh4 ,wright1 #bb1 #bbd-bcj1 #aijf4 ,fenner1 #bi1 #bag-bcd1 #aiaj4 ,bowen1 #ci1 #age-aia2 #dj1 #afa-ahe1 #aiae4 ,pirsson1 #ej1 #aaf-aba1 #ahie2 #g1 #bga-bhj1 #ahii4 ,smyth1 #cf1 #cc-df1 #aiac4 ,murgoci1 #bj1 #acc-ade1 #aije4 ,barrell1 #ac1 #bgi-bif1 #aijb4 ,lindgren1 #c1 #cja-cad1 #ahig2 #i1 #bfi-bhb1 #aijj4 ,ransome1 #e1 #cee-cge1 #ahih4 ,cross1 #d1 #aae-ada1 #ahig4 ,hague1 #a1 #dde-deg1 #ahif4 ,pogue1 #bh1 #bah-bch1 #aiji4 ,warren1 #be1 #ab-cf1 #aijh4 ,goldman1 #ci1 #bfa-bhh1 #aiae4 ,washington and ,pirsson1 ,belknap ,mts41 #bj1 #cdd-cec1 #aije2 #bb1 #dci-deg1 #dic-eae1 #aijf4 ----1 ,red ,hill1 #bc1 #beg-bgf1 #dcc-ddg1 #aijg4 ----1 ,tripyramid ,mt41 #ca1 #dje-dca1 #aiaa4 ,footnote #aca3 ,quantitative ,classification of ,igneous ,rocks1 ,cross1 ,iddings1 ,pirsson and ,washington1 ,chicago1 #aijc4 ,petrogenesis1 ,c4 ,doelter1 ,braunschweig1 #aijf4 ,igneous ,rocks1 vols4 #a and #b1 ,j4 ,p4 ,iddings1 ,new ,york1 #aiji and #aiac4 ,problem of ,volcanism1 ,iddings1 ,new ,haven1 #aiad4 ,natural ,history of ,igneous ,rocks1 ,alfred ,harker1 ,london1 #aiji4 ,igneous ,rocks and their ,origin1 ,r4 ,a4 ,daly1 ,new ,york1 #aiad4 ,footnote #acb3 ,among these may be mentioned3 ,rosenbusch u4 ,wlfing1 ,physiog4 der petrog4 wicht4 ,min41 ,stuttgart1 #aije4 ,iddings1 ,j4 ,p41 ,rock-,minerals1 #ast ed41 ,new ,york1 #aijf4 ,johannsen1 ,a41 ,manual of ,petrographic ,methods1 ,new ,york1 #aiad4 ,winchell1 ,n4 ,h4 and ,a4 ,n41 ,elements of ,optical ,mineralogy1 ,new ,york1 #aiji4 ,footnote #acc3 ,we may mention here1 for example1 the work in mineralogy of ,penfield1 noticed in the accompanying chapter on mineralogy4 ,in addition to the accurate determination of the composition and constants of many minerals1 some of which have importance from the petrographic standpoint1 we owe to him more than anyone the recognition of fluorine and hydroxyl in a variety of species1 and thereby the perception of their pneumatolytic origin4 ,his papers have been published almost entirely in the ,journal4 ,footnote #acd3 ,wright1 ,methods of ,petrographic-,microscopic ,research1 ,carnegie ,inst41 ,washington1 #aiaa1 and various papers2 many in the ,journal4 ,footnote #ace3 ,conf4 ,wright's work quoted above and the various manuals previously mentioned4 ,footnote #acf3 ,kemp1 ,hand-book of ,rocks1 #c;d ed41 ,new ,york1 #aijd4 ,pirsson1 ,rocks and ,rock-,minerals1 ,new ,york1 #aiaj4 ,footnote #acg3 ,williams1 ,g4 ,h41 ,u4 ,s4 ,geol4 ,surv41 ,bull4 #fb1 ,washington1 #ahij4 ,footnote #ach3 ,van ,hise1 ,treatise on ,metamorphism1 ,u4 ,s4 ,geol4 ,surv41 ,monograph #ag4 ,footnote #aci3 ,f4 ,w4 ,clarke1 ,u4 ,s4 ,geol4 ,surv41 ,bull4 #eia1 #aiae4 ,footnote #adj3 ,hillebrand1 ,analysis of ,silicate and ,carbonate ,rocks1 ,u4 ,s4 ,geol4 ,surv41 ,bull4 #dbb1 #aiaj4 ,footnote #ada3 ,washington1 ,chemical ,analysis of ,rocks1 pp4 #bjj1 ,new ,york1 #aiaj4 ,footnote #adb3 ,id41 ,chemical ,analyses of ,igneous ,rocks 7#ahhd-aijj71 ,u4 ,s4 ,geol4 ,surv41 ,prof4 ,paper1 ,no4 #ad1 #aijc4 ,footnote #adc3 ,osann1 ,beitr4 zu chem4 ,petrogr41 ,,ii ,teil4 ,anal4 d4 ,eruptivgest41 #ahhd-aijj1 ,stuttgart1 #aije4 ,footnote #add3 ,washington1 ibid41 #b;d ed41 ,u4 ,s4 ,geol4 ,surv41 ,prof4 ,paper #ii1 pp4 #abaf1 #aiag4 ,footnote #ade3 ,clarke1 ,u4 ,s4 ,geol4 ,surv41 ,bull4 #faf1 #aiaf4 ,footnote #adf3 ,fouqu and ,michel-,lvy1 ,synthese des ,mineraux et des ,roches1 ,paris1 #ahhb4 ,footnote #adg3 ,morozewicz1 ,exper4 ,untersuch4 u4 ,bildung der ,min4 im ,magma1 ,min4 petr4 ,mitt41 #ah1 #ahih4 ,footnote #adh3 ,doelter1 ,synthetische ,studien1 ,n4 ,jahrb4 ,min4 #ahig1 #a1 #a-bf4 ,allg4 chem4 ,mineralogie1 etc4 ,footnote #adi3 ,tamman1 ,krystallisieren und ,schmelzen1 #aijc4 ,footnote #aej3 ,st4 ,meunier1 ,les ,mthodes de ,synthse en ,minralogie1 ,paris1 #ahia4 ,footnote #aea3 ,vogt1 ,mineralbildung in ,smelzmassen1 ,christiania1 #ahib2 ,silikatschmelzlsungen1 #a and #b1 #aijc1 #aijd1 and various other papers1 esp4 in ,min4 petr4 ,mitt41 vols4 #bd and #be1 #aijf4 ,footnote #aeb3 ,h4 ,e4 ,boeke1 ,grundlagen der physikalisch-chemischen ,petrographie1 ,berlin1 #aiae4 ,,viii ,,the ,,growth ,,of ,,mineralogy ,,from #ahah ,,to #aiah ,by ,,william ,e4 ,,ford ,mineralogy to-day would certainly be generally considered one of the minor members of the group of the ,geological ,sciences4 ,we commonly look upon it in the light of an useful handmaiden1 whose chief function is to serve the other branches1 and we are inclined to forget that1 in reality1 mineralogy was the first to be recognized and1 with considerable truth1 might be claimed as the mother of all the others4 ,minerals1 because of their frequent beauty of color and form1 and their uses as gems and as ornamental stones1 were the first inorganic objects to excite wonder and comment and we find many of them named and described in very early writings4 ,theophrastus 7#cfh-bhd ,b4 ,c471 a famous pupil of ,aristotle1 wrote a treatise 8,on ,stones0 in which he collected a large amount of information about minerals and fossils4 ,the elder ,pliny 7#bc-gi ,a4 ,d471 more than three centuries later1 in his ,natural ,history1 described and named many of the commoner minerals4 ,at this time it was natural that no clear distinction should be drawn between minerals and rocks1 or even between minerals and fossils4 ,as long as all study of the materials of the earth's crust was concerned with their superficial characters1 it was logical to include everything under the single head4 ,there were some writers in the early centuries of the ,christian era1 however1 who believed that fossils had been derived from living animals but the majority considered them to be only strange and unusual forms of minerals4 ,during many succeeding centuries little was added to the general store of geological knowledge and it was not until the beginning of the sixteenth century1 that any further notable progress was made4 ,agricola 7#adid-aeee7 was a physician1 who1 for a time1 lived in the mining district of ,joachimstal4 ,he studied and described the minerals that he collected there4 ,he was the first to give careful and critical descriptions of minerals1 of their crystals and general physical properties4 ,unfortunately1 he also did not realize the fundamental distinction between fossils and minerals1 and probably because of his influence this error persisted1 even until the middle of the eighteenth century4 ,but1 naturally1 as the number of scientific students increased1 the number of those who rejected this conclusion grew1 until at last1 the true character of fossils was established4 ,the keen interest in minerals and fossils which was aroused by this controversy1 together with the rapid extension of mining operations1 drew the attention of scientific men to other features of the earth's surface and led to a more extended investigation of its characters and thus to the development of geology proper4 ,it is interesting to note also that mineralogy was the first of the ,geological ,sciences to be officially recognized and taught by the universities4 ,although1 as has been shown1 the beginnings of mineralogy lie in the remote past1 the science1 as we know it to-day1 can be said to have had practically its whole growth during the last one hundred years4 ,of the more than one thousand mineral species that may now be considered as definitely established hardly more than two hundred were known in the year #ahjj and these were only partially described or understood4 ,it is true that ,hay1 the 8father of crystallography10 had before this date discovered and formulated the laws of crystal symmetry1 and had shown that rational relations existed between the intercepts upon the axes of the different faces of a crystal4 ,it was not until #ahji1 however1 that ,wollaston described the first form of a reflecting goniometer1 and thus made possible the beginning of exact investigation of crystals4 ,the distinctions between the different crystal groups were developed by ,bernhardi1 ,weiss and ,mohs between the years #ahjg and #ahbj1 while the ,naumann system of crystal symbols was not proposed until #ahbf4 ,the fact that doubly refracting minerals also polarize light was discovered by ,malus in #ahjh1 and in #ahac ,brewster first recognized the optical differences between uniaxial and biaxial minerals4 ,the modern science of chemistry was also just beginning to develop at this period1 enabling mineralogists to make analyses more and more accurately and thus by chemical means to establish the true character of minerals1 and to properly classify them4 ,franz von ,kobell1 on page #cgb of his 8,geschichte der ,mineralogie10 somewhat poetically describes the condition of the science at this period as follows3 8,with the end of the eighteenth and the commencement of the nineteenth centuries exact investigations in mineralogy first began4 ,the mineralogist was no longer content with approximate descriptions of minerals1 but strove rather to separate the essential facts from those that were accidental1 to discover definite laws1 and to learn the relations between the physical and chemical characters of a mineral4 ,the use of mathematics gave a new aspect to crystallography1 and the development of the optical relationships opened a magnificent field of wonderful phenomena which can be described as a garden gay with flowers of light1 charming in themselves and interesting in their relations to the forces which guide and govern the regular structure of matter40 ,in the ,medical ,repository 7vol4 #b1 p4 #aad1 ,new ,york1 #agii71 there occurs the following notice3 8,since the publication of the last number of the ,repository an ,association has been formed in the city of ,new ,york #8for the investigation of the ,mineral and ,fossil bodies which compose the fabric of the ,globe2 and1 more especially1 for the ,natural and ,chemical ,history of the ,minerals and ,fossils of the ,united ,states1' by the name and style of ,the ,american ,mineralogical ,society40 ,with this announcement is given an advertisement in which the society 8earnestly solicits the citizens of the ,united ,states to communicate to them1 on all mineralogical subjects1 but especially on the following3 #a1 concerning stones suitable for gun flints2 #b1 concerning native brimstone or sulphur2 #c1 concerning salt-petre2 #d1 concerning mines and ores of lead40 ,further the society asks 8that specimens of all kinds be sent to it for examination and determination40 ,this marks apparently the beginning of the serious study of the science of mineralogy in the ,united ,states4 ,from this time on1 articles on mineralogical topics appeared with increasing frequency in the ,medical ,repository4 ,most of these were brief and were largely concerned with the description of the general characters and modes of occurrence of various minerals4 ,nothing of much moment from the scientific point of view appeared until many years later1 but the growing interest in things mineralogical was clearly manifest4 ,an important stimulus to this increasing knowledge and discussion was furnished by ,col4 ,george ,gibbs who1 about the year #ahjh1 brought to this country a large and notable mineral collection4 ,in the ,medical ,repository 7vol4 #aa1 p4 #bac1 #ahjh71 is found a notice of this collection1 a portion of which is reproduced below3 8,gibbs' grand ,collection of ,minerals4 ,one of the most zealous cultivators of mineralogy in the ,united ,states is ,col4 ,g4 ,gibbs of ,rhode ,island and his taste and his fortune have concurred in making him the proprietor of the most extensive and valuable assortment of minerals that probably exists in ,america4 ,this rich collection consists of the cabinets possessed by the late ,mons4 ,gigot ,d',orcy of ,paris and the ,count ,gregoire de ,rozamonsky1 a ,russian nobleman1 long resident in ,switzerland4 ,to which the present proprietor has added a number1 either gathered by himself on the spot1 or purchased in different parts of ,europe4444 ,the whole consists of about twenty thousand specimens4 ,a small part of this collection was opened to amateurs at ,rhode ,island1 the last summer1 and the next1 if circumstances permit1 the remainder will be exposed40 ,in #ahjb ,benjamin ,silliman was appointed professor of chemistry and mineralogy in ,yale ,college4 ,after the ,gibbs ,collection was brought to ,america he spent much time with the owner in studying it and1 as a result1 ,col4 ,gibbs offered to place the collection on exhibition in ,new ,haven if suitable quarters would be furnished by the college4 ,this was quickly accomplished and in #ahaj1 #ahaa and #ahab the collection was transferred to ,new ,haven and arranged for exhibition by ,col4 ,gibbs4 ,later1 in #ahbe1 it was purchased by ,yale and served as the nucleus about which the present ,museum collection of the ,university has been formed4 ,there is no doubt but that the presence at this early date of this large and unusual mineral collection had a great influence upon the development of mineralogical science at ,yale1 and in the country at large4 ,in the year #ahaj ,dr4 ,archibald ,bruce started the 8,american ,mineralogical ,journal10 the title page of which reads in part as follows3 8,the ,american ,mineralogical ,journal1 being a ,collection of ,facts and ,observations tending to elucidate the ,mineralogy and ,geology of the ,united ,states of ,america1 together with other ,information relating to ,mineralogy1 ,geology and ,chemistry1 derived from ,scientific ,sources40 ,unfortunately the health of ,dr4 ,bruce failed1 and the journal lasted only through its first volume4 ,it had1 however1 8been most favorably received10 as ,silliman remarks1 and it was felt that another journal of a similar type should be instituted4 ,such a suggestion was made by ,col4 ,gibbs to ,professor ,silliman in #ahag and this led directly to the founding of the ,american ,journal of ,science in #ahah under the latter's editorship4 ,although the field of the ,journal at the very beginning was made broad and inclusive it has always published many articles on mineralogical subjects4 ,three of its editors-in-chief have been eminent mineralogists1 and without question it has been the most important single force in the development of this science in the country4 ,more than #hjj well-established mineral species have been described since the year #ahjj1 of which approximately #aej have been from ,american sources4 ,more than two-thirds of the articles describing these new ,american minerals have first appeared in the pages of the ,journal4 ,while the description of new species is not always the most important part of mineralogical investigation1 still these figures serve to show the large part that the ,journal has played in the growth of ,american mineralogy4 ,it is convenient to review the progress in ,mineralogy according to the divisions formed by the different series1 consisting of fifty volumes each1 in which the ,journal has been published4 ,these divisions curiously enough will be found to correspond closely to four quite definite phases through which mineralogical investigation in ,america has passed4 ,the first series covered the years from #ahag to #ahde4 ,in looking through these volumes one finds a large number of mineralogical articles1 the work of many contributors4 ,the great majority of these papers are purely descriptive in character1 frequently giving only general accounts of the mineral occurrences of particular regions4 ,however1 a number of articles dealing with more detailed physical and chemical descriptions of rare or new species also belong in this period4 ,among the mineralogists engaged at this time in the description of individual species1 none was more indefatigable than ,charles ,u4 ,shepard4 ,he was graduated from ,amherst ,college in #ahbd1 at the age of twenty4 ,in #ahbg he became assistant to ,professor ,silliman in ,new ,haven1 continuing in this position for four years4 ,later he was a lecturer in natural history at ,yale1 and was at various times connected with ,amherst ,college and the ,south ,carolina ,medical ,college at ,charleston4 ,his articles on mineralogy were very numerous4 ,he assigned a large number of new names to minerals1 although with the exception of some half dozen cases1 these have later been shown to be varieties of minerals already known and described1 rather than new species4 ,in spite1 however1 of his frequent hasty and inaccurate decision as to the character of a mineral1 his influence on the progress of mineralogy was marked4 ,his great enthusiasm and ceaseless industry throughout a long life could not help but make a definite contribution to the science4 ,his 8,treatise on ,mineralogy0 will be spoken of in a later paragraph4 ,he died in ,may1 #ahhf1 having published his last paper in the ,journal in the previous ,september4 ,the first book on mineralogy published in ,america was that by ,parker ,cleaveland1 professor of mathematics1 natural philosophy1 chemistry and mineralogy in ,bowdoin ,college4 ,the first edition was printed in #ahaf and an exhaustive notice is given in the first volume of the ,journal 7#a1 #ce1 #cjh1 #ahah72 a second edition followed in #ahbb4 ,in his preface ,cleaveland gives an interesting discussion concerning the two opposing ,european methods of classifying minerals4 ,the ,german school1 led by ,werner1 classified minerals according to their external characters while the ,french school1 following ,hay1 put the emphasis on the 8true composition40 ,cleaveland remarks that 8the ,german school seems to be most distinguished by a technical and minutely descriptive language2 and the ,french1 by the use of accurate and scientific principles in the classification or arrangement of minerals40 ,he1 himself1 tried to combine in a measure the two methods1 basing the fundamental divisions upon the chemical composition and using the accurate description of the physical properties to distinguish similar species and varieties from each other4 ,cleaveland's mineralogy was followed nearly twenty years later by the ,treatise on ,mineralogy by ,charles ,u4 ,shepard already mentioned4 ,the first part of this book was published in #ahcb4 ,this contained chiefly an account of the natural history classification of minerals according to the general plan adopted by ,mohs1 the ,austrian mineralogist4 ,the second part of the book1 which appeared in #ahce1 gave the description of individual species1 the arrangement here being an alphabetical one throughout4 ,subsequent editions appeared in #ahdd1 #aheb and #aheg4 ,james ,dwight ,dana was graduated from ,yale ,college in #ahcc at the age of twenty4 ,four years later 7#ahcg7 he published 8,the ,system of ,mineralogy10 a volume of #ehj pages4 ,the appearance of this book was an event of surpassing importance in the development of the science4 ,the book1 of course1 depended largely upon the previous works of ,hay1 ,mohs1 ,naumann and other ,european mineralogists1 but was in no sense merely a compilation from them4 ,dana1 particularly in his discussion of mathematical crystallography1 showed much original thought4 ,he also proved his originality by proposing and using an elaborate system of classification patterned after those already in use in the sciences of botany and zoology4 ,he later became convinced of the undesirability of this method of classification and abandoned it entirely in the fourth edition of the ,system1 published in #ahed1 substituting for it the chemical classification which1 in its essential features1 is in general use to-day4 ,the ,system of ,mineralogy started in this way in #ahcg1 has continued by means of successive editions to be the standard reference book in the subject4 ,the various editions appeared as follows3 ,i1 #ahcg2 ,,ii1 #ahdd2 ,,iii1 #ahej2 ,,iv1 #ahed2 ,v1 #ahfh2 ,,vi1 #ahib 7by ,edward ,s4 ,dana74 ,j4 ,d4 ,dana also contributed numerous mineralogical articles to the first series of volumes of the ,journal4 ,it is interesting to note that they are chiefly concerned with the more theoretical aspects of the subject1 in fact they constitute practically the only articles of such a character that appeared during this period4 ,among the subjects treated were crystallographic symbols1 formation of twin crystals2 pseudomorphism1 origin of minerals in metamorphosed limestones1 origin of serpentine1 classification of minerals1 etc4 ,the volumes of the ,second ,series of the ,journal covered the years from #ahdf through #ahgj4 ,this period was characterized by great activity in the study of the chemical composition of minerals4 ,a number of skilled chemists1 notably ,j4 ,lawrence ,smith1 ,george ,j4 ,brush and ,frederick ,a4 ,genth1 began about #ahej a long series of chemical investigations of ,american minerals4 ,very few articles during this time paid much attention to the physical properties of the minerals under discussion1 practically no description of optical characters was attempted1 and only occasionally were the crystals of a mineral mentioned4 ,j4 ,d4 ,dana was almost the only writer who constantly endeavored to discover the fundamental characters and relationships in minerals4 ,he published many articles in these years which were concerned chiefly with the classification and grouping of minerals1 with similarities in the crystal forms of different species1 with relations between chemical composition and crystal form1 chemical formulas1 mineral nomenclature1 etc4 ,the following titles give an idea of the character of the more important series of articles by him which belong to this category3 ,on the isomorphism and atomic volume of some minerals 7#i1 #bbj1 #ahej72 various notes and articles on homomorphism of minerals 7#ag1 #he1 #hf1 #baj1 #dcj2 #ah1 #ce1 #aca1 #ahed72 on a connection between crystalline form and chemical constitution1 with some inferences therefrom 7#dd1 #hi1 #beb1 #cih1 #ahfg74 ,a great many new mineral names were proposed between #ahej and #ahgj1 a large number of which have continued to be well-recognized species4 ,but there was also a tendency1 which has not wholly disappeared even now1 to base a mineral determination upon insufficient evidence1 and to propose a new species with but little justification for it4 ,in this connection a quotation from the introduction by ,j4 ,d4 ,dana to the #crd ,supplement to the ,system of ,mineralogy 7#dth edition7 published in the ,journal 7#bb1 page #bdf1 #ahef71 will be of interest4 ,he says3 8,it is a matter of regret1 that mineral species are so often brought out1 especially in this country1 without sufficient investigation and full description4 ,it is not meeting the just demands of the science of mineralogy to say that a mineral has probably certain constituents1 or to state the composition in a general way without a complete and detailed analysis1 especially when there are no crystallographic characters to afford the species a good foundation4 ,we have a right to demand that those who name species1 should use all the means the science of the age admits of1 to prove that the species is one that nature will own1 for only such belong to science1 and if enough of the material has not been found for a good description there is not enough to authorize the introduction of a new name in the science4 ,the publication of factitious species1 in whatever department of science1 is progress not towards truth1 but into regions of error2 and often much and long labor is required before the science recovers from these backward steps40 ,j4 ,lawrence ,smith was born in #ahah and died in #ahhc4 ,he was a graduate of the ,university of ,virginia and of the ,medical ,college of ,charleston and later spent three years studying in ,paris4 ,shortly after the completion of his studies he went to ,turkey as an advisor to the government of that country in connection with the growing of cotton there4 ,during this time he investigated the emery mines of ,asia ,minor1 and wrote a memoir upon them which was later published by the ,french ,academy4 ,he served as professor of chemistry in the ,university of ,virginia and later held the same chair in the ,university of ,illinois4 ,he published a long series of papers on the chemical composition of minerals and meteorites1 as well as on pure chemical subjects4 ,among the more notable of his contributions are the 8,memoir on ,emery0 7#ahej71 a series of papers on the 8,rexamination of ,american ,minerals0 7#ahec7 written with the collaboration of ,george ,j4 ,brush1 and his 8,memoir on ,meteorites0 7#ahee74 ,illustration3 ,ge4 ,j4 ,brush ,george ,j4 ,brush entered on his scientific career at the moment when science and scientific methods of research were just beginning to be appreciated in this country1 and he soon became one of the leading pioneers in the movement4 ,while his half century of active service was largely occupied by administrative duties in connection with the ,sheffield ,scientific ,school1 his interest in mineralogy never flagged4 ,his papers on mineralogical subjects number about thirty1 all of which were published in the ,journal4 ,these began in #ahdi1 even before his graduation from college1 and continued until his last paper 7in collaboration with ,s4 ,l4 ,penfield7 appeared in #ahhc4 ,three of the early papers were written with ,j4 ,lawrence ,smith as noted above4 ,these papers first set in this country the standard for thorough and accurate scientific mineral investigation4 ,later in life he was active in the development of the remarkable mineral locality at ,branchville1 ,conn41 and1 with the collaboration of ,e4 ,s4 ,dana1 published in the ,journal 7#ahgh-ij7 five important articles on its minerals4 ,this locality1 with the exception of the zinc deposits at ,franklin ,furnace1 ,n4 ,j41 was the most remarkable yet discovered in this country4 ,nearly forty different mineral species were found there1 of which nine 7mostly phosphates7 were new to science4 ,there has certainly been no other series of descriptive papers on a mineralogical locality of equal importance published in this country4 ,in addition to publishing original papers1 ,brush did considerable editorial work in connection with the fourth 7#ahed7 and fifth 7#ahfh7 editions of the ,system of ,mineralogy and the ,appendices to them4 ,his ,manual of ,determinative ,mineralogy1 with a series of determinative tables adapted from similar ones by von ,kobell1 was first published in #ahgd4 ,it was revised in #ahgh and later rewritten by ,s4 ,l4 ,penfield4 ,this book did much to make possible the rapid and accurate determination of mineral species4 ,throughout his life1 ,brush was an enthusiastic collector of minerals1 building up the notable collection that now bears his name4 ,perhaps1 however1 his most important contribution to the development of mineralogy in ,america lay rather in his influence upon his many students4 ,with his enthusiasm for accurate and painstaking investigation he was an inspiration to all who came in contact with him and his own field and science in general owes much to that influence4 ,among the early mineralogists in this country1 who were concerned in the chemical analyses of minerals1 none accomplished more or better work than ,frederick ,a4 ,genth4 ,he was born in ,germany in #ahbj and lived in that country until #ahdh1 when he came to the ,united ,states and settled in ,philadelphia4 ,he had studied in various ,german universities and worked under some of the most famous chemists of that time4 ,his papers in mineralogy number more than seventy-five1 in the great majority of which chemical analyses are given4 ,he published fifty-four successive articles1 the greater part of which appeared in the ,journal1 which were entitled ,contributions to ,mineralogy4 ,in these he gave descriptions of more than two hundred different minerals1 most of which were accompanied by analyses4 ,he described more than a dozen new and well-established mineral species4 ,he was especially interested in the rarer elements and many of his analyses were of minerals containing them4 ,especially interesting was his work with the tellurides1 the species coloradoite1 melonite and calaverite being first described by him4 ,a long and important investigation was recorded on ,corundum1 8,its ,alterations and ,associate ,minerals10 published in the ,proceedings of the ,american ,philosophical ,society in #ahgc 7#ac1 #cfa74 ,dr4 ,genth died in #ahic4 ,the period from #ahfj until #ahge was not very productive in mineralogical investigations4 ,the first ten volumes of the ,third ,series of the ,journal1 covering the years #ahga-ahgf1 contained mineralogical articles by only some fifteen different authors4 ,but from that time on1 the amount of work done and the number of investigators grew rapidly4 ,with this increase in activity came also a decided change in the character of the work4 ,the period between #ahga and #ahie can be characterized as one in which all the various aspects of mineral investigation received more nearly equal prominence4 ,while the chemical composition of minerals still held rightly its prominent place1 the investigation of the crystallographic and optical characters and the relationships existing between all three were of much more frequent occurrence4 ,edward ,s4 ,dana commenced his scientific work by publishing in #ahgb an article on the crystals of datolite which was probably the first ,american article concerned wholly with the description of the crystallography of a mineral4 ,samuel ,l4 ,penfield began his important investigations in #ahgg and the first articles by ,frank ,w4 ,clarke appeared during this period4 ,the first edition of the ,text ,book of ,mineralogy by ,edward ,s4 ,dana with its important chapters on ,crystallography and ,optical ,mineralogy was published in #ahgg and his revision of the ,system of ,mineralogy 7sixth edition7 appeared in #ahib4 ,unquestionably the foremost figure in ,american mineralogy during this period was that of ,samuel ,l4 ,penfield4 ,he embodied in an unusual degree the characters making for success in this science1 for few investigators in mineralogy have shown1 as he did1 equal facility in all branches of descriptive mineralogy4 ,he was a skilled chemist and possessed in a high degree that ingenuity in manipulation so necessary to a great analyst4 ,he was also an accurate and resourceful crystallographer and optical mineralogist4 ,his contributions to the science of mineralogy can be partially judged by the following brief summary of his work4 ,he published over eighty mineralogical papers1 practically all of which were printed in the ,journal4 ,these included the descriptions of fourteen new mineral species1 the establishment of the chemical composition of more than twenty others1 and the crystallization of about a dozen more4 ,by a series of brilliant investigations he established the isomorphism between fluorine and the hydroxyl radical4 ,he first enunciated the theory that the crystalline form of a mineral was due to the mass effect of the acid present rather than that of the bases4 ,he contributed also a number of articles on the stereographic projection and its use in crystallographic investigations1 devising a series of protractors and scales to make possible the rapid and accurate use of this projection in solving problems in crystallography4 ,penfield was born in #ahef1 was graduated from the ,sheffield ,scientific ,school in #ahgg and immediately became an assistant in the chemical laboratory of that institution4 ,at this time he1 together with his colleague ,horace ,l4 ,wells1 made the analyses of the minerals from the newly discovered ,branchville locality4 ,he spent the years #ahhj and #ahha in studying chemistry in ,germany1 returning to ,yale as an instructor in mineralogy in the fall of #ahha4 ,except for another semester in ,europe at ,heidelberg he continued as instructor and professor of mineralogy in the ,sheffield ,scientific ,school until his early death in #aijf4 ,it is difficult to choose for mention the names of other investigators in ,mineralogy during this period4 ,toward its end a great many writers contributed to the pages of the ,journal1 more than fifty different names being counted for the volumes #da to #ej of the ,third ,series4 ,many of these are still living and still active in scientific research4 ,mention should be made of ,frank ,w4 ,clarke1 who contributed many important articles concerning the chemical constitution of the silicates4 ,his work on the mica and zeolite groups is especially noteworthy4 ,the work of ,w4 ,h4 ,hillebrand1 particularly in regard to his analytical investigations of the minerals containing the rarer elements1 was of great importance4 ,the name of ,w4 ,e4 ,hidden should be remembered1 because1 with his keen and discriminating eye and active search for new mineral localities1 he was able to make many additions to the science4 ,in glancing over the indices to the ,journal the close interrelation of mineralogy to the other sciences is strikingly shown by the fact that so many scientists whose particular fields are along other lines have published occasional mineralogical papers4 ,frequently a young man has commenced with mineralogical investigations and then later been drawn definitely into one of these allied subjects4 ,men1 who have won their reputation in chemistry1 physics1 and all the various divisions of geology1 even that of palaeontology1 have all contributed articles distinctly mineralogical in character4 ,for this reason the number of ,american writers who have published what may be called casual papers on mineralogy is very great in comparison to the number of those who continue such publications over a series of years4 ,that the subject of meteorites is one which has been constantly studied by ,american mineralogists and petrographers is shown by the long list of papers concerning it that have been published in the ,journal2 it should1 therefore1 be considered briefly here4 ,many of these papers are short and of a general descriptive nature but others which give more fully the chemical1 mineralogical and physical details are numerous4 ,among the earlier writers on this subject ,benjamin ,silliman1 ,jr41 and ,c4 ,u4 ,shepard should be mentioned4 ,the latter was the first to recognize a new mineral in the ,bishopville meteorite which he called chladnite4 ,the same substance was afterwards found in a terrestial occurrence and was more accurately described by ,kenngott under the name of enstatite4 ,j4 ,lawrence ,smith later showed that these two substances were identical4 ,smith did a large amount of important chemical work on meteorites4 ,he was the first to note the presence of ferrous chloride in meteoric iron1 the mineral being afterwards named lawrencite in his honor4 ,the iron-chronium sulphide1 daubreelite1 was also first described by him4 ,other names that should be mentioned in this connection are those of ,a4 ,w4 ,wright who studied the gaseous constituents of meteorites1 ,g4 ,f4 ,kunz1 ,w4 ,e4 ,hidden1 ,a4 ,e4 ,foote and ,h4 ,a4 ,ward1 all of whom published numerous descriptions of these bodies4 ,among the more recent workers in this field the names of ,g4 ,p4 ,merrill and ,o4 ,c4 ,farrington deserve especial mention4 ,the publication of the ,fourth ,series of the ,journal began in #ahif4 ,although the years since then have seen a great amount of very important work accomplished1 the history of the period is fresh in the minds of all and as the majority of the active workers are still living and productive it seems hardly necessary to go into great detail concerning it4 ,twenty years ago it seemed to some mineralogists that the science could almost be considered complete4 ,all the commoner minerals had certainly been discovered and exhaustively studied4 ,little apparently was left that could be added to our knowledge of them4 ,new occurrences would still be recorded1 new crystal habits would be observed1 and an occasional new and small crystal face might be listed1 but few facts of great importance seemed undiscovered4 ,this view was not wholly justified because new facts of interest and importance have continuously been brought forward1 and the finding of new minerals does not appear to diminish in amount with the years4 ,the work of the investigators on the ,united ,states ,geological ,survey along these lines is especially noteworthy4 ,this last of our periods1 however1 is chiefly signalized by a practically new development along the lines that might be characterized as experimental mineralogy4 ,new ways have been discovered in which to study minerals4 ,the important but hitherto baffling problems of their genesis1 together with their relations to their surroundings1 and to associated minerals1 have been attacked by novel methods4 ,in this pioneer work that of the ,geophysical ,laboratory of the ,carnegie ,institution of ,washington has been of the greatest importance4 ,this laboratory was established in #aije and1 under the directorship of ,arthur ,l4 ,day1 a notable corps of investigators has been assembled and remarkable work already accomplished4 ,while the field of investigation of the laboratory is broader than that of mineralogy1 including much that belongs to petrography1 vulcanology1 etc41 still the greater part of the work done can be properly classed as mineralogical in character and should be considered here4 ,because of its great value1 however1 it was felt that an authoritative1 although necessarily1 under existing conditions1 a brief1 account of it should be given4 ,a concise summary of the objects1 methods and results of the investigations of the laboratory has been kindly prepared by a member of its staff1 ,dr4 ,r4 ,b4 ,sosman1 and is given later4 ,during the last few years another line of investigation has been opened by the discovery of the effect of crystalline structure upon ,x-rays4 ,through the refraction or reflection of the ,x-ray by means of the ordered arrangement of the particles forming the crystalline network1 we are apparently going to be able to discover much concerning the internal structure of crystals4 ,and1 partly through these discoveries1 is likely to come in turn the solution of the hitherto insolvable mystery of the constitution of matter4 ,without doubt the multitudinous facts of mineralogy assembled during the past century by the painstaking investigation of a large number of scientists are destined to play a large part in the solution of this problem4 ,further1 it does not seem too bold a prophecy to suggest1 that the time will come when it will be possible to assemble all these unorganized facts that we know about minerals into a harmonious whole and that we shall be then able to formulate the underlying and fundamental principles upon which they all depend4 ,these are the great problems for the future of mineralogical investigation4 ,,ix ,,the ,,work ,,of ,,the ,,geophysical ,,laboratory ,,of ,,the ,,carnegie ,,institution ,,of ,,washington ,by ,r4 ,b4 ,,sosman ,there are three methods of approach to the great problem of rock formation4 ,the first undertakes to reproduce by suitable laboratory experiments some of the observed changes in natural rocks4 ,the second seeks to apply the principles of physical chemistry to a great body of carefully gathered statistics4 ,the third method of attack is like the first in being a laboratory method1 and like the second in seeking to apply existing knowledge to the association of minerals as found in rocks1 but in its procedure differs widely from both4 ,it consists of bringing together pure materials under measurable conditions1 and thus in establishing by strictly quantitative methods the relations in which minerals can exist together under the conditions of temperature and pressure that have the power to affect such relations4 ,it is to this third method of investigation of the problems of the rocks that the ,geophysical ,laboratory has been devoted since its establishment in #aije4 ,it has proved entirely practicable to make quantitative studies of the relations among the principal earth-forming oxides 7silica1 alumina1 magnesia1 lime1 soda1 potash1 and the oxides of iron7 over a very wide range of temperatures4 ,the resources of physics have proved adequate to establish temperature with a high degree of precision and to measure the quantity of energy involved in the various reactions4 ,the chemist has been able to obtain materials in a high degree of purity1 and to follow out in detail the chemical relationships that exist among the earth-forming oxides4 ,the petrographic laboratory has been available for the comparison of synthetic laboratory products with the corresponding natural minerals4 ,it has also proved entirely practicable to extend the same methods of research to some of the principal ore minerals such as the sulphides of copper4 ,other information which is certain to be of ultimate economic value has also come out of the thorough study of the silicates1 which are basic materials for the vast variety of industries which are classed under the name of ceramic industries4 ,the best example of this is the facility with which the experience and the personnel of the laboratory has been adapted to the very important problem of manufacturing an adequate supply of optical glass for the needs of the ,united ,states in the present war4 ,it has further been possible to show within the last two years that rock formation in which volatile ingredients play a necessary and determining part can be completely studied in the laboratory with as much precision as though all the components were solids or liquids4 ,along with the laboratory work on the formation of minerals and rocks has gone an increasing amount of field work on the activities of accessible volcanoes1 such as ,kilauea and ,vesuvius1 where the fusion and recrystallization of rocks on a large scale can be observed and studied4 ,there was once a time when the confidence of the laboratory in the capacity of physics and chemistry to solve geological problems was not shared by all geologists4 ,there were some who were inclined to view with considerable apprehension the vast ramifications and complications of natural rock formation as a problem impossible of adequate solution in the laboratory4 ,it is1 therefore1 a matter of satisfaction to all those who have participated in these efforts to see the evidences of this apprehension disappearing gradually as the work has progressed4 ,a careful appraisement of the situation to-day1 after ten years of activity1 reveals the fact that the tangible grounds for anxiety about the accessibility of the problems which were confronted at first are now for the most part dissipated4 ,it will not be possible to review in detail the lines of work sketched above4 ,an outline of the synthetic work on systems of the mineral oxides and a paragraph on the volcano researches will perhaps suffice to indicate the general plan and purpose of the laboratory's work4 ,it should be added that the results of many of the researches of the laboratory1 detailed below1 have been published in the pages of the ,journal 7see #ba1 #hi1 #aijf1 and later volumes74 ,mineral ,researches4--,the mineral studies include3 ,i4 ,one-component systems3 silica1 with its numerous polymorphic forms and their relations to temperature and the conditions of rock formation2 alumina2 magnesia2 and lime4 ,,ii4 ,two-component systems3 silica-alumina1 including sillimanite and related minerals2 silica-magnesia1 including the tetramorphic metasilicate ,mg,si,o#c2 silica-lime1 including wollastonite2 the alkali silicates1 particularly with reference to their equilibria with carbon dioxide and with water2 ferric oxide-lime2 alumina-lime2 alumina-magnesia1 including spinel2 and hematite-magnetite1 a solid-solution series of an unusual type4 ,,iii4 ,three-component systems3 silica-alumina-magnesia1 completed but not yet published2 silica-alumina-lime1 complete1 including the compounds that enter into the composition of portland cement2 silica-magnesia-lime1 completed but not yet published1 including1 however1 published work on the diopside-forsterite-silica system1 and on the ,ca,si,o#c-,mg,si,o#c series2 and alumina-magnesia-lime4 ,,iv4 ,four components3 ,si,o#b-;,al#b,o#c-,mg,o-,ca,o3 the incomplete system anorthite-forsterite-silica2 ,si,o#b-;,al#b,o#c-;,ca,o-,na#b,o3 the series of lime-soda feldspars 7albite-anorthite71 and the series nephelite 7carnegieite7-anorthite2 ,si,o#b-;,al#b,o#c-,na#b,o-,k#b,o3 the sodium-potassium nephelites4 ,v4 ,five components3 ,si,o#b-;,al#b,o#c-,mg,o-,ca,o-,na#b,o3 the ternary system diopside-anorthite-albite 7haplo-basaltic and haplo-dioritic magmas74 ,fairly complete studies have also been made of the mineral sulphides of iron1 copper1 zinc1 cadmium1 and mercury1 and the conditions controlling the secondary enrichment of copper sulphide ores are now being investigated4 ,in connection with the sulphide investigations1 the hydrated oxides of iron have been studied chemically and microscopically and the results will soon be ready for publication4 ,throughout the work the mere accumulation of bodies of facts has been held to be secondary in importance to the development of new methods of attack and the evaluation of new general principles1 and the specific problems studied have been selected from this point of view4 ,volcano ,researches4--,a branch of the laboratory's work that is of general as well as petrological interest is the study of active volcanoes4 ,observations and collections have been made at ,kilauea1 ,vesuvius1 ,etna1 ,stromboli1 ,vulcano1 and 7through the courtesy of the directors of the ,national ,geographic ,society7 ,katmai in ,alaska4 ,the great importance of gases in volcanicity is emphasized by all the studies4 ,the active gases include hydrogen and water vapor1 carbon monoxide and carbon dioxide1 and sulphur and its oxides1 as well as a variety of other compounds of lesser importance4 ,the crater of ,kilauea proves to be an active natural gas-furnace1 in which reactions are continuously occurring among the gases1 often resulting in making the lava basin hotter at the surface than it is at some depth4 ,these reactions are being studied in the laboratory on mixtures of the pure constituent gases in known proportions1 in order to lay the foundation for accurate interpretation and prediction concerning the gases as actually collected from the volcanoes themselves4 ,x ,,the ,,progress ,,of ,,chemistry ,,during ,,the ,,past ,,one ,,hundred ,,years ,by ,,horace ,l4 ,,wells and ,,harry ,w4 ,,foote ,introduction4 ,as we look back to the time of the founding of the ,journal in #ahah1 we see that the science of chemistry had recently made and was then making great advances4 ,that the scientific men of those days were much impressed with what was being accomplished is well shown by the following statement made in an early number of the ,journal 7#c1 #ccj1 #ahba7 by its founder in reviewing ,gorham's ,elements of ,chemical ,science4 ,he says3 8,the present period is distinguished by wonderful mental activity2 it might indeed be denominated as the intellectual age of the world4 ,at no former period has the mind of man been directed at one time to so many and so useful researches40 ,a very remarkable revolution in chemical ideas had recently taken place4 ,soon after the discovery of oxygen by ,priestley in #aggd1 and the subsequent discovery by ,cavendish that water was formed by the combustion of hydrogen and oxygen1 ,lavoisier had explained combustion in general as oxidation1 thus overthrowing the curious old phlogiston theory which had prevailed as the basis of chemical philosophy for nearly a century4 ,the era of modern chemistry had thus begun1 and the additional views that matter was indestructible and that chemical compounds were of constant composition had been generally accepted at the beginning of the nineteenth century4 ,dalton had announced his atomic theory in #ahjb1 having based it largely upon the law of multiple proportions which he had previously discovered1 and he had begun to express the formulas for compounds in terms of atomic symbols4 ,in #ahjh ,gay-,lussac had discovered his law of gas combination in simple proportions1#aec a law of supreme importance in connection with the atomic theory1 but neither he nor ,dalton had seen this theoretical connection4 ,avogadro had understood it1 however1 and in #ahaa had reached the momentous conclusion that all gases and vapors have equal numbers of molecules in equal volumes at the same temperature and pressure4 ,davy in #ahjg had isolated the alkali-metals1 sodium and potassium1 by means of electrolysis1 thus practically dispelling the view that certain earthy substances might be elementary2 and about four years later he had demonstrated that chlorine was an element1 not an oxide as had been supposed previously1 thus overthrowing ,lavoisier's view that oxygen was the characteristic constituent of all acids4 ,at the time that our period of history begins1 the atomic theory had been accepted generally1 but in a somewhat indefinite form1 since little attention had been paid to ,avogadro's principle1 and since ,dalton had used only the principle of greatest simplicity in writing the formulas of compounds1 considering water as ,,ho and ammonia ,,nh1 for example4 ,at this time1 however1 ,berzelius for ten or fifteen years had been devoting tremendous energy to the task of determining the atomic weights of nearly all of the elements then known by analyzing their compounds4 ,he had confirmed the law of multiple proportions1 accepted the atomic theory1 and utilized ,avogadro's principle1 and it is an interesting coincidence that his first table of atomic weights was published in the year #ahah4 ,an interesting account of the views on chemistry held at about that time was published in the ,journal by ,denison ,olmsted 7#aa1 #cdi1 #ahbf2 #ab1 #a1 #ahbg71 who had recently become professor of natural philosophy in ,yale ,college4 ,the most illustrious ,european chemists of that time were ,berzelius of ,sweden1 ,davy of ,england1 and ,gay-,lussac of ,france1 and the curious circumstance may be mentioned that all three of them and also ,benjamin ,silliman1 the founder of the ,journal1 were born within a period of eight months in #aggh-aggi4 ,in this country ,robert ,hare of ,philadelphia and ,benjamin ,silliman were undoubtedly the most prominent chemists of those days4 ,hare is best known for his invention of the compound blowpipe1 but his contributions to the ,journal were very numerous1 beginning almost with the first volume and continuing for over thirty years4 ,among the first of these contributions was a most vigorous but well-merited attack upon a ,doctor ,clark of ,cambridge1 ,england1 who had copied his invention without giving him proper credit4 ,he begins 7#b1 #bha1 #ahbj7 by saying3 8,dr4 ,clark has published a book on the gas blowpipe in which he professes a sincere desire to render everyone his due4 ,that it would be difficult for the conduct of any author to be more discordant with these professions1 ,i pledge myself to prove in the following pages40 ,hare also invented a galvanic battery which he called a 8deflagrator10 consisting of a large number of single cells in series4 ,with this1 using carbon electrodes1 he was able to obtain a higher temperature than with his oxy-hydrogen blowpipe4 ,he was the first to apply galvanic ignition to blasting 7#ba1 #aci1 #ahcb71 and he first carried out electrolyses with the use of mercury as the cathode 7#cg1 #bfg1 #ahci74 ,in this way he prepared metallic calcium and other metals from solutions of their chlorides1 while the principle employed by him has in recent times been used as the basis of a very important process for manufacturing caustic potash and soda4 ,silliman1 who had become an intimate friend of ,hare during two periods of chemical study under ,woodhouse in ,philadelphia in #ahjb-ahjd1 and who soon afterwards spent fourteen months as a student abroad1 chiefly in ,england and ,scotland1 took a broad interest in science and gave much attention to geology as well as to chemistry4 ,in spite of this divided interest and his work as a teacher1 popular scientific lecturer1 and editor1 he found time for a surprising amount of original chemical work4 ,for instance1 using ,hare's deflagrator1 he showed that carbon was volatilized in the electric arc 7#e1 #ajh1 #ahbb72 he was the first in this country to prepare hydrofluoric acid 7#f1 #ced1 #ahbc71 and he first detected bromine in one of our natural brines 7#ah1 #adb1 #ahcj74 ,atomic ,weights4 ,as soon as the atomic theory was accepted1 the relative weights of the atoms became a matter of vital importance in connection with formulas and chemical calculations4 ,in advancing his theory1 ,dalton had made some very rough atomic weight determinations1 and it has been mentioned already that ,berzelius1 at the time that our historical period begins1 was engaged in the prodigious task of accurately determining these constants for nearly all the known elements4 ,it is recorded that he analyzed quantitatively no less than two thousand compounds in connection with this work during his career4 ,his table of #ahah has proved to be remarkably accurate for that pioneer period1 and it indicates his remarkable skill as an analyst4 ,it is to be observed that ,berzelius in this early table made use of ,avogadro's principle in connection with elements forming gaseous compounds1 and thus obtained correct formulas and atomic weights in such cases1 but that in many instances his atomic weights and those now accepted bear the relation of simple multiples to one another1 because he had then no means of deciding upon the formulas of many compounds except the rule of assumed simplicity4 ,for example1 the two oxides of iron now considered to be ,fe,o and ,fe#b,o#c he regarded as ,fe,o#b and ,fe,o#c1 knowing as he did that the ratio of oxygen in them was #b to #c1 and believing that a single atom of iron in each was the simplest view of the case1 so that as the consequence of these formulas the atomic weight of iron was then considered to be practically twice as great in its relation to oxygen as at present4 ,these old atomic weights of ,berzelius1 used with the corresponding formulas1 were just as serviceable for calculating compositions and analytical factors as though the correct multiples had been selected4 ,as time went on1 the true multiples were gradually found from considerations of atomic heats1 isomorphism1 vapor densities1 the periodic law1 and so on1 and suitable changes were made in the chemical formulas4 ,berzelius used #ajj parts of oxygen as the basis of his atomic weights1 a practice which was generally followed for several decades4 ,dalton1 however1 had originally used hydrogen as unity as the basis1 and this plan finally came into use everywhere1 as it seemed to be more logical and convenient1 because hydrogen has the smallest atomic weight1 and also because the atomic weights of a number of common elements appeared to be exact multiples of that of hydrogen1 thus giving simpler numbers for use in calculations4 ,within a few years a slight change has been made by the adoption of oxygen as exactly #af as the basis1 which gives hydrogen the value of #ajjh4 ,as early as #ahae1 ,prout1 an ,english physician1 had advanced the view that hydrogen is the primordial substance of all the elements1 and consequently that the atomic weights are all exact multiples of that of hydrogen4 ,this hypothesis has been one of the incentives to investigations upon atomic weights1 for it has been found that these constants in the cases of a considerable number of the elements are very close to whole numbers when based upon hydrogen as unity1 or even still closer when based upon oxygen as #af4 ,with our present knowledge ,prout's hypothesis may be regarded as disproved for nearly all the elements whose atomic weights have been accurately determined1 but the close or even exact agreement with it in a few cases is still worthy of consideration4 ,there is an interesting letter from ,berzelius to ,b4 ,silliman1 ,jr41 in the ,journal 7#dh1 #cfi1 #ahde7 in which ,berzelius considers the theory entirely disproved4 ,for a long time entire reliance was placed upon the atomic weights obtained by ,berzelius1 but it came to be observed that the calculation of carbon from carbon dioxide appeared to give high results in certain cases1 so that doubt arose as to the accuracy of ,berzelius's work4 ,consequently in #ahdj ,dumas1 assisted by his pupil ,stas1 made a new determination of the atomic weight of carbon1 and found that the number obtained by ,berzelius1 #abab1 was slightly too large4 ,subsequently ,dumas determined more than twenty other atomic weights1 but this great amount of work did not bring about any considerable improvement1 for it appears that ,dumas did not greatly excel ,berzelius in accuracy1 and that the latter had made one of his most noticeable errors in connection with carbon4 ,soon after assisting ,dumas in the work upon carbon1 ,stas began his very extensive and accurate1 independent determinations1 leading to the publication of a book in #ahfg describing his work4 ,stas made many improvements in methods by the use of great care in purifying the substances employed1 and especially by using large quantities of material in his determinations1 thus diminishing the proportional errors in weighing4 ,his results1 which dealt with most of the common elements1 were accepted with much confidence by chemists everywhere4 ,stas reached the conclusion that there could be no real foundation for ,prout's hypothesis1 since so many of his atomic weights varied from whole numbers1 and this opinion has been generally accepted4 ,the first accurate atomic weight determination published in the ,journal was that by ,mallett on lithium 7#bb1 #cdi1 #ahef2 #bh1 #cdi1 #ahei71 showing a result almost identical with that accepted at the present time4 ,johnson and ,allen's determination 7#ce1 #id1 #ahfc7 on the rare element csium was carried out with extraordinary accuracy4 ,lee1 working with ,wolcott ,gibbs1 made good determinations on nickel and cobalt 7#b1 #dd1 #ahga74 ,the work of ,cooke on antimony 7#ae1 #da1 #ajg1 #ahgh7 was excellent4 ,concerning the more recent work published elsewhere than in the ,journal1 attention should be called particularly to the investigations that have been carried on for the past twenty-five years by ,richards and his associates at ,harvard ,university4 ,richards has shown masterly ability in the selection of methods and in avoiding errors4 ,his results have displayed such marvelous agreements among repeated determinations by the same and by different processes as to inspire the greatest confidence4 ,his work has been very extensive1 and it is a great credit to our country that this atomic weight work1 so superior to all that has been previously done1 is being carried out here4 ,it may be mentioned that for a number of years the decision in regard to the atomic weights to be accepted has been in the hands of an ,international ,committee of which our fellow countryman ,f4 ,w4 ,clarke has been chairman4 ,in connection with this position and previously1 ,clarke has done valuable service in re-calculating and summarizing atomic weight determinations4 ,analytical ,chemistry4 ,analysis is of such fundamental importance in nearly every other branch of chemical investigation that its development has been of the utmost importance in connection with the advancement of the science4 ,it attained1 therefore1 a comparatively early development1 and one hundred years ago it was in a flourishing condition1 particularly as far as inorganic qualitative and gravimetric analysis were concerned4 ,there is no doubt that ,berzelius1 whose atomic weight determinations have already been mentioned1 surpassed all other analysts of that time in the amount1 variety1 and accuracy of his gravimetric work4 ,he lived through three decades of our period1 until #ahdh4 ,during the past century there has been constant progress in inorganic analysis1 due to improved methods1 better apparatus and accumulated experience4 ,an excellent work on this subject was published by ,h4 ,rose1 a pupil of ,berzelius1 and the methods of the latter1 with many improvements and additions by the author and others1 were thus made accessible4 ,fresenius1 who was born in #ahah1 did much service in establishing a laboratory in which the teaching of analytical chemistry was made a specialty1 in writing text-books on the subject and in establishing in #ahfb the 8,zeitschrift fr analytische ,chemie10 which has continued up to the present time4 ,besides ,berzelius1 who was the first to show that minerals were definite chemical compounds1 there have been many prominent mineral analysts in ,europe1 among whom ,rammelsberg and ,bunsen may be mentioned1 but there came a time towards the end of the nineteenth century when the attention of chemists1 particularly in ,germany1 was so much absorbed by organic chemistry that mineral analysis came near becoming a lost art there4 ,it was during that period that an ,english mineralogist1 visiting ,new ,haven and praising the mineral analyses that were being carried out at ,yale1 expressed regret that there appeared to be no one in ,england1 or in ,germany either1 who could analyze minerals4 ,the best analytical work done in this country in the early part of our period was chiefly in connection with mineral analysis1 and a large share of it was published in the ,journal4 ,henry ,seybert1 of ,philadelphia1 in particular1 showed remarkable skill in this direction1 and published numerous analyses of silicates and other minerals1 beginning in #ahbb4 ,it was he who first detected boric acid in tourmaline 7#f1 #aee1 #ahbb71 and beryllium in chrysoberyl 7#h1 #aje1 #ahbd74 ,his methods for silicate analyses were very similar to those used at the present time4 ,j4 ,lawrence ,smith in #ahec described his method for determining alkalies in minerals 7#af1 #ec71 a method which in its final form 7#a1 #bfi1 #ahga7 is the best ever devised for the purpose4 ,he also described 7#ae1 #id1 #ahec7 a very useful method1 still largely used in analytical work1 for destroying ammonium salts by means of aqua regia4 ,carey ,lea 7#db1 #aji1 #ahff7 described the well-known test for iodides by means of potassium dichromate4 ,f4 ,w4 ,clarke 7#di1 #dh1 #ahgj7 showed that antimony and arsenic could be quantitatively separated from tin by the precipitation of the sulphides in the presence of oxalic acid4 ,in #ahfd ,wolcott ,gibbs 7#cg1 #cdf7 began an important series of analytical notes from the ,lawrence ,scientific ,school1 and he worked out later many difficult analytical problems1 particularly in connection with his extensive researches upon the complex inorganic acids4 ,from #ahej on1 ,brush and his students made many important investigations upon minerals1 and from #ahgg ,penfield 7#ac1 #dbe71 beginning with an analysis of a new mineral from ,branchville1 ,connecticut1 described by ,brush and ,e4 ,s4 ,dana1 displayed remarkable skill and industry in this kind of work4 ,both of the writers of this article were fortunate in being associated with ,penfield in some of his researches upon minerals and one of us began as he did with the ,branchville work4 ,it is probably fair to say that ,penfield did the most accurate work in mineral analysis that has ever been accomplished1 and that he was similarly successful in crystallography and other physical branches of mineralogy4 ,the ,american analytical investigations that have been mentioned were all published in the ,journal1 with the exception of a part of ,gibbs's work4 ,many other ,american workers at mineral analysis might be alluded to here1 but only the excellent work of a number of chemists in the ,united ,states ,geological ,survey will be mentioned4 ,among these ,hillebrand deserves particular praise for the extent of his investigations and for his careful researches in improving the methods of rock analysis4 ,to our own ,professor ,gooch especial praise must be accorded for the very large number of analytical methods that have been devised1 or critically studied1 by him and his students1 and for the excellent quality of this work4 ,the publications in the ,journal from his laboratory began in #ahij 7#ci1 #ahh71 and the extraordinary extent of this work is shown by the fact that the three hundredth paper from the ,kent ,laboratory appeared in ,may1 #aiah4 ,these very numerous and important investigations have been of great scientific and practical value1 and they have formed a striking feature of the ,journal for nearly #cj years4 ,in #aiab ,gooch published his 8,methods in ,chemical ,analysis10 a book of over #ejj pages1 in which the work in the ,kent ,chemical ,laboratory up to that time was concisely presented4 ,among the many workers who have assisted in these investigations1 ,p4 ,e4 ,browning1 ,w4 ,a4 ,drushel1 ,f4 ,s4 ,havens1 ,d4 ,a4 ,kreider1 ,c4 ,a4 ,peters1 ,i4 ,k4 ,phelps and ,r4 ,g4 ,van ,name are particularly prominent4 ,besides many other useful pieces of apparatus1 the perforated filtering crucible was devised by ,gooch1 and this has brought his name into everyday use in all chemical laboratories4 ,volumetric analysis was originated by ,gay-,lussac1 who described a method for chlorimetry in #ahbd1 for alkalimetry in #ahbh1 and for the determination of silver and chlorides in #ahcb4 ,margueritte devised titrations with potassium permanganate in #ahdf1 while ,bunsen1 not far from the same time1 introduced the use of iodine and sulphur dioxide solutions for the purpose of determining many oxidations and reductions4 ,we owe to ,mohr some improvements in apparatus and a ,german text-book on the subject1 while ,sutton wrote an excellent ,english work on volumetric analysis1 of which many editions have appeared4 ,while volumetric analysis began to be used less than one hundred years ago1 its applications have been gradually extended to a very great degree1 and it is not only exceedingly important in investigations in pure chemistry1 but its use is especially extensive in technical laboratories where large numbers of rapid analyses are required4 ,not a few volumetric methods have been devised or improved in the ,united ,states1 but mention will be made here only of ,cooke's important method for the determination of ferrous iron in insoluble silicates1 published in the ,journal 7#dd1 #cdg1 #ahfg72 to ,penfield's method for the determination of fluorine in #ahgh2 and to the more recent general method of titration with an iodate in strong hydrochloric acid solutions1 due to ,l4 ,w4 ,andrews1 a number of applications of which have been worked out in the ,sheffield ,laboratory4 ,a considerable amount of work with gases had been done by ,priestley1 ,scheele1 ,cavendish1 ,lavoisier1 ,dalton1 ,gay-,lussac1 and others before our hundred-year period began4 ,cavendish1 about #aghj1 had analyzed atmospheric air with remarkable accuracy1 and had even separated the argon from it and wondered what it was1 and later ,gay-,lussac had shown great skill in the study of gas reactions4 ,during our period gas analysis has been further developed by many chemists4 ,bunsen1 in particular1 brought the art to a high degree of perfection in the course of a long period beginning about #ahch1 the last edition of his 8,methods of ,gas ,analysis0 having been published in #ahgg4 ,important devices for the simplification of gas analysis in order that it might be used more conveniently for technical purposes have been introduced by ,orsat in ,france and by ,winkler1 ,hempel and ,bunte in ,germany4 ,it appears that our countryman ,morley has surpassed all others in accurate work with gases in connection with his determinations of the combining weights and volumes of hydrogen and oxygen about the year #ahia4 ,some of his publications have appeared in the ,journal 7#cj1 #adj1 #ahhe2 #da1 #bbj1 #ahia2 and others74 ,electrolytic analysis1 involving the deposition of metals1 or sometimes of oxides1 usually upon a platinum electrode1 was brought into use in #ahfe by ,wolcott ,gibbs through an article published in the ,journal 7#ci1 #eh1 #ahfe74 ,he there described the electrolytic precipitation of copper and of nickel by the methods still in use4 ,the application of the process has been extended to a number of other metals1 and it has been largely employed1 particularly in technical analyses4 ,important investigations and excellent books on this subject have been the contributions of ,edgar ,f4 ,smith of the ,university of ,pennsylvania1 and the useful improvement1 the rotating cathode1 was devised by ,gooch and described in the ,journal 7#ae1 #cbj1 #aijc74 ,general ,inorganic ,chemistry4 ,the ,chemical ,symbols4--,it is to ,berzelius that we owe our symbols for the atoms1 derived usually from their ,latin names1 such as ,c for carbon1 ,na for sodium1 ,cl for chlorine1 ,fe for iron1 ,ag for silver1 and ,au for gold4 ,we owe to him also the use of small figures to show the number of atoms in a formula1 as in ,n#b,o#e4 ,this was a marked improvement over the hieroglyphic symbols proposed by ,dalton1 which were set down as many times as the atoms were supposed to occur in formulas1 forming groups of curious appearance1 but in some respects not unlike some of our modern developed formulas4 ,the advantages of ,berzelius's symbols were their simplicity1 legibility1 and the fact that they could be printed without the need of special type4 ,it is true that at a later period ,berzelius used certain symbols with horizontal lines crossing them to represent double atoms1 and that these made some difficulty in printing4 ,it should be mentioned also that ,berzelius at one time made an effort to simplify formulas by placing dots over other symbols to represent oxygen1 and commas to represent sulphur atoms4 ,examples of these are3 a,s1 calcium sulphate2 ,fe1 iron disulphide ,this form of notation was quite extensively employed for a time1 especially by mineralogists1 but it was entirely abandoned later4 ,it is interesting to notice that ,dalton1 who lived until #ahdd1 to reach the age of #gh1 differed from other chemists in refusing to accept the letter-symbols of ,berzelius4 ,in a letter written to ,graham in #ahcg he said3 8,berzelius's symbols are horrifying4 ,a young student in chemistry might as soon learn ,hebrew as to make himself acquainted with them4 ,they appear like a chaos of atoms 444 and to equally perplex the adepts of science1 to discourage the learner1 as well as to cloud the beauty and simplicity of the atomic theory40 ,this forcibly expressed opinion was apparently tinged with self-esteem1 but there is no doubt that ,dalton was sincere in believing that the atoms were best represented by his circular symbols1 because1 as is well known1 he thought that all the atoms were spherical in form1 and it is evident that circles give the proper picture of spherical objects4 ,at the present time some insight as to the structure of atoms is being gained1 and it appears possible that the time may come when pictures of their external appearance that are not wholly imaginary may be made4 ,changes in ,formulas4--,even before the year #ahbf1 ,berzelius displayed great skill in arriving at many formulas that agree with our present ones1 for example1 ,h#b,o for water1 ,zn,cl#b for zinc chloride1 ,n#b,o#e for nitric acid 7anhydride71 ,ca,o for calcium oxide1 ,,co and ,,co#b for the oxides of carbon1 and many others4 ,but at the same period other authorities1 especially ,gay-,lussac in ,france and ,gmelin in ,germany1 on account of a lack of appreciation for ,avogadro's principle and for other reasons1 such as the use of symbols to represent combining weights rather than atoms1 were using different formulas for some of these compounds1 such as ,,ho1 ,zn,cl and ,,no#e1 so that their formulas for many of the compounds of hydrogen1 chlorine1 nitrogen and several other elements differed from those of ,berzelius4 ,the employment of different formulas involved the use of different atomic or combining weights4 ,for example1 with the formula ,h#b,o for water the composition by weight requires the ratio #a to #af for the weights of the hydrogen and oxygen atoms1 while with ,,ho the ratio is #a to #h4 ,berzelius attempted to bring about greater uniformity in formulas and atomic weights by making changes in his table of atomic weights published in #ahbf4 ,he practically doubled the relative atomic weights of hydrogen1 chlorine1 nitrogen1 and of the other elements that gave twice as many atoms in his formulas as in those of others1 and at the same time he wrote the symbols of these elements with a bar across them to indicate that they represented double atoms4 ,for example1 he wrote3 ,h,o ,zn,cl ,n,o#e1 instead of ,h#b,o1 ,zn,cl#b ,n#b,o#e ,this appears to have been an unfortunate concession to the views of others on the part of ,berzelius1 for the barred symbols were not generally adopted1 partly on account of difficulties in printing1 and the great achievement in theory made by him was lost sight of for a long period of time4 ,the ,law of ,atomic ,heats4--,in #ahai1 ,dulong and ,petit of ,france1 from experiments upon the specific heats of a number of solid elementary substances1 came to the conclusion that the atoms of simple substances have equal capacities for heat1 or in other words1 that the specific heats of elements multiplied by their atomic weights give a constant called the atomic heat4 ,for instance1 the specific heats of sulphur1 iron1 and gold have been given as #jbjbf1 #jaaj1 and #jjcbd1 while their atomic weights are about #cb1 #ef1 and #aig1 respectively2 hence the atomic heats obtained by multiplication are #fdhc1 #faaf1 and #fchc4 ,further investigations showed that the atomic heats display a considerable variation4 ,those of carbon1 boron1 beryllium1 and silicon are very low at ordinary temperatures1 although they increase and approach the usual values at higher temperatures4 ,more recent work has shown1 however1 that the specific heats of other elements vary greatly with the temperature1 almost disappearing at the temperature of liquid hydrogen1 and hence possibly disappearing entirely at the absolute zero1 where the electrical resistance of the metals appears to vanish likewise4 ,it has been found that most of the solid elements near ordinary temperatures give atomic heats that are approximately #fd4 ,berzelius applied the law in fixing a number of atomic weights1 and its importance for this purpose is still recognized4 ,it may be mentioned here that two well-known ,yale men1 ,w4 ,o4 ,mixter and ,e4 ,s4 ,dana1 while students in ,bunsen's laboratory at ,heidelberg in #ahgc1 made determinations of the specific heats of boron1 silicon1 and zirconium4 ,this was the first determination of this constant for zirconium1 and it was consequently important in establishing the atomic weight of that element4 ,isomorphism and ,polymorphism4--,mitscherlich observed in #ahah that certain phosphates and arsenates have the same crystalline form1 and afterwards he reached the conclusion that identity in form indicates similarity in composition in connection with the number of atoms and their arrangement4 ,this law of isomorphism was of much assistance in the establishment of correct formulas and consequently of atomic weights4 ,for instance1 since the carbonates of barium1 strontium1 and lead crystallize in the same form1 the oxides of these metals must have analogous formulas4 ,from such considerations ,berzelius was able to make several improvements in his atomic weight table of #ahbf4 ,mitscherlich was the first to observe two forms of sulphur crystals1 and from this and other cases of dimorphism or of polymorphism it became evident that analogous compounds were not necessarily always isomorphous1 a circumstance which has restricted the application of the law to some extent4 ,besides its application in fixing analogous formulas1 the law of isomorphism has come to be of much practical use in the understanding and simplification of the formulas for minerals1 for these natural crystals very often contain several isomorphous compounds in varying proportions1 and an understanding of this 8isomorphous replacement10 as it is called1 makes it possible to deduce simple general formulas for them4 ,in some cases isomorphism takes place to a greater or less extent between substances which are not chemically similar1 and this brings about a variation in composition which at times has caused confusion4 ,for instance1 the mineral pyrrhotite has a composition which usually varies between ,fe#g,s#h and ,fe#aa,s#ab1 and both these formulas have been assigned to it4 ,it was recently shown by ,allen1 ,crenshaw and ,johnston in the ,journal 7#cc1 #afi1 #aiab7 that this is a case where the compound ,fe,s is capable of taking up various amounts of sulphur isomorphously4 ,the idea of solid solution was advanced by van't ,hoff to explain the crystallization of mixtures1 including cases of evident isomorphism4 ,this view has been widely accepted1 and it has been particularly useful in cases where isomorphism is not evident4 ,solid solution between metals has been found to be exceedingly common1 many alloys being of this character4 ,a case of this kind was observed by ,cooke and described in the ,journal 7#bj1 #bbb1 #ahee74 ,he prepared two well-crystallized compounds of zinc and antimony to which he gave the formulas ,zn#c,sb and ,zn#b,sb1 but he observed that excellent crystals of each could be obtained which varied largely in composition from these formulas4 ,as the two compounds were dissimilar in their formulas and crystalline forms1 ,cooke assumed that isomorphism was impossible and concluded 8that it is due to an actual perturbation of the law of definite proportions1 produced by the influence of mass40 ,we should now regard this as a case of solid solution4 ,a ,lack of ,confidence in ,avogadro's ,principle4--,one reason why chemists were so slow in arriving at the correct atomic weights and formulas was a partial loss of confidence in ,avogadro's principle4 ,about #ahbf the young ,french chemist ,dumas devised an excellent method for the determination of vapor densities at high temperatures1 and his results and those of others showed some discrepancies in the expected densities4 ,for example1 the vapor density of sulphur was found to be about three times too great1 that of phosphorus twice too great1 that of mercury vapor and that of ammonium chloride only about half large enough to correspond to the values expected from analogy and other considerations4 ,thus1 one volume of oxygen with two volumes of hydrogen make two volumes of steam1 but only one third of a volume of sulphur vapor was found to unite with two volumes of hydrogen to make two volumes of hydrogen sulphide4 ,berzelius saw clearly that the results pointed to the existence of such molecules as ,s#f1 ,p#d1 and ,hg#a1 but it was not generally realized in those days that ,avogadro's rule is fundamentally reliable1 and ,berzelius himself appears to have lost confidence in it on account of these complications1 for he did not apply ,avogadro's principle to decisions about atomic weights1 except in the cases of substances gaseous at ordinary temperatures4 ,electro-chemical ,theories4--,the observation was made by ,nicholson and ,carlisle in #ahjj that water was decomposed into its constituent gases by the electric current4 ,then in #ahjc ,berzelius and ,hisinger found that salts were decomposed into their bases and acids by the same agency1 and in #ahjg ,davy isolated potassium1 sodium1 and other metals afterwards1 by a similar decomposition4 ,since those early times a vast amount of attention has been paid to the relation of electricity to chemical changes1 a relation that is evidently of great importance from the fact that while electric currents decompose chemical compounds1 these currents1 on the other hand1 are produced by chemical reactions4 ,berzelius was particularly prominent in this direction1 and in #ahai he published an elaborate electro-chemical theory4 ,he believed that atoms were electrically polarized1 and that this was the cause of their combination with one another4 ,he extended this idea to groups of atoms1 particularly to oxides1 and regarded these groups as positive or negative1 according to the excess of positive or negative electricity derived from their constituent atoms and remaining free4 ,he thus arrived at his dualistic theory of chemical compounds1 which attained great prominence and prevailed for a long time in chemical theory4 ,according to this idea1 each compound was supposed to be made up of a positive and a negative atom or group of atoms4 ,for example1 the formulas for potassium nitrate1 calcium carbonate1 and sulphuric acid corresponded to ,k#b,o4,n#b,o#e1 ,ca,o4,,co#b and ,h#b,o4,,so#c where we now write ,,kno#c1 ,ca,c,o#c and ,h#b,,so#d1 and the theory was extended to embrace organic compounds also4 ,the eminent ,english chemist and physicist ,faraday announced the important law of electro-chemical equivalents in #ahcd4 ,this law shows that the quantities of elements set free by the passage of a given quantity of electricity through their solutions correspond to the chemical equivalents of those elements4 ,faraday made a table of the equivalents of a number of elements1 regarding them important in connection with atomic weights1 but at that time no sharp distinction was usually made between equivalents and atomic weights1 and it was not fully realized that one atom of a given element may be the electrical equivalent of several atoms of another4 ,faraday's law1 which is still regarded as fundamentally exact1 has been of much practical use in the measurement of electric currents and in calculations connected with electro-chemical processes4 ,in discussing his experiments1 ,faraday made use of several new terms1 such as 8electrolyte0 for a substance which conducts electricity when in solution1 and is thus 8electrolyzed10 8electrode10 8anode10 and 8cathode10 terms that have come into general use1 and finally 8ions0 for the particles that were supposed to 8wander0 towards the electrodes to be set free there4 ,this term 8ion0 remained in comparative obscurity for more than half a century1 when it was brought into great prominence among chemists by ,arrhenius in connection with the ionic theory4 ,cannizzaro's ,ideas4--,up to about #ahfi chaos reigned among the formulas used by different chemists4 ,various compound radicals and numerous type-formulas were employed1 dualistic and unitary formulas of several kinds were in use1 but the worst feature of the situation was the fact that more than one system of atomic weights was in vogue1 so that water might be written ,,ho1 ,h,o1 or ,h#bj and similar discrepancies might appear in nearly all formulas containing elements of different valencies4 ,in #aheh1 however1 an article by the ,italian chemist ,cannizzaro appeared in which the outlines of a course in chemical philosophy were presented4 ,this acquired wide circulation in the form of a pamphlet at a chemical convention somewhat later1 and it dealt so clearly and ably with ,avogadro's principle1 ,dulong and ,petit's law1 and other points in connection with formulas that it led to a rapid and almost universal reform among those who were using unsatisfactory formulas4 ,at about this time also the dualistic formulas of ,berzelius were generally abandoned1 and hydrogen came to be regarded as the characteristic element of all acids4 ,for instance1 ,ca,o4,,so#c1 called 8sulphate of lime10 came to be written ,ca,s,o#d and was called 8calcium sulphate10 and while it had been shown as early as #ahae by ,davy that 8iodic acid10 ,i#b,o#e1 showed no acid reaction until it was combined with water1 the accumulation of similar facts led to the formulation of sulphuric acid as ,h#b,,so#d instead of ,,so#c or ,h#b,o4,,so#c1 and that of other 8oxygen acids0 in a similar way4 ,as a necessary consequence of this view of acids1 the bases came to be regarded as compounds of the 8hydroxyl0 group1 ,,oh4 ,therefore the formula for caustic soda came to be written ,na,o,h instead of ,na#b,o4,h#b,o1 and so on4 ,the ,periodic ,system of the ,elements4--,the periodicity of the elements in connection with their atomic weights was roughly grasped by ,newlands in ,england1 who announced his 8law of octaves0 in #ahfc4 ,this was at the time when the atomic weights were being modified and their numerical relations properly shown4 ,the subject was worked out more fully by ,l4 ,meyer in ,germany a little later1 but it was most clearly and elaborately presented by the ,russian chemist ,mendeleff in #ahfi4 ,in order that this subject may be explained to some extent ,mendeleff's table is given here1 with the addition of the recently discovered elements and some other modifications4 ,groups ,i ,,ii ,,iii ,a ,b ,a ,b ,a ,b ,typical ,r#b,o ,,ro ,r#b,o#c ,compounds ,r,cl ,r,cl#b ,r,cl#c ,,rh -- 7,,rh#b7 -- -- 7,,rh#c7 ,series #a #b ,lithium ,beryllium ,boron #fid #ia #aaj #c ,sodium ,magnesium ,aluminium #bcjj #bdcb #bga #d ,potassium ,calcium ,scandium #ciaj #djjg #dda #e ,copper ,zinc ,gallium #eceg #fecg #fii #f ,rubidium ,strontium ,yttrium #hedc #hgfc #hij #g ,silver ,cadmium ,indium #ajghh #aabdj #aadh ,lanthanum #h ,csium ,barium #acij to99 #acbha #acghg ,lutecium #agd4j #i ,gold ,mercury ,thallium #aigb #bjjf #bjdj #aj ---- ,radium ---- #bbfd ,groups ,,iv ,v ,a ,b ,a ,b ,typical ,,ro#b ,r#b,o#e ,compounds ,r,cl#d ,r,cl#c -- 7,,rh#d7 -- ,,rh#c ,series #a #b ,carbon ,,nitrogen #abjj #adja #c ,silicon ,phosphorus #bhc #cajd #d ,titanium ,vanadium #dha #eaj #e ,germanium ,arsenic #gbe #gdif #f ,zirconium ,niobium #ijf #ice #g ,tin #aaij ,antimony #abjb 7,cerium7 #h #adjbe ,tantalum 7,lutecium7 #ahae #agd4j #i ,lead ,bismuth #bjgaj #bjhj #aj ,thorium ---- #bibd ,groups ,,vi ,,vii ,,viii ,a ,b ,a ,b ,a ,b ,typical ,,ro#c ,r#b,o#g 7,,ro#d7 -- ,compounds ,r,cl#b -- ,r,cl -- ,r -- ,,rh#b -- ,,rh -- ,r ,series #a ,,hydrogen ,,helium #ajjh #cii #b ,,oxygen ,,fluorine ,,neon #afjj #aij #bjb #c ,sulphur ,,chlorine ,,argon #cbjg #cedf #cihh #d ,chromium ,manganese ,iron #ebj #edic #eehd ,cobalt #ehig ,nickel #ehfh #e ,selenium ,bromine ,,krypton #gib #giib #hbib #f ,molybdenum ---- #ajj ,ruthenium #ifj #ajag ,rhodium #ajbi ,palladium #ajfg #g ,tellurium ,iodine ,,xenon #abge #abfib #acjb #h ,tungsten ---- #ahh ,osmium #ahdj #aiji ,iridium #aica ,platinum #aieb #i ---- ---- ,,niton #bbbd #aj ,uranium #bche 99 ,lanthanum1 ,cerium1 ,praseodymium1 ,neodymium1 ----1 ,rare,earth #acij #adjbe #adjf #addc ,metals3 ,gadolinium1 ,terbium1 ,dysprosium1 ,holmium1 ,erbium1 #aegc #aeib #afbe #afce #afgg 99 ,samarium1 ,europeum1 ----1 ,rare,earth #aejd #aebj ,metals3 ,thulium1 ,ytterbium1 ,lutecium1 #afhe #agbj #agdj ,,note4--,distinctions in printing3 ,,gaseous ,,elements4 ,other non-metallic elements1 metallic elements4 ,the heavy line encloses approximately the acid-forming elements4 ,in this table the elements arranged in the order of their atomic weights fall into eight groups where the known oxides progress regularly1 with the exception of two or three elements1 from ,r#b,o in ,group ,i to ,r#b,o#g in ,group ,,vii1 while in ,group ,,viii two oxides 7of ruthenium and osmium7 are known which carry the progression to ,,ro#d4 ,it was pointed out by ,mendeleff that1 with the exception of series #a and #b at the top of the table1 the alternate members of the groups show particularly close relationships4 ,these subordinate groups1 marked ,a and ,b1 in most cases show remarkable analogies and gradations in their properties1 for example1 in the alkali-metals from lithium to csium1 and in the halogens from fluorine to iodine4 ,the two divisions of a group do not usually show very close relations to each other1 except in their valency1 and they even display1 in several instances1 opposite gradations in chemical activity in the order of their atomic weights4 ,for instance1 csium stands at the electro-positive end1 while gold stands at the electro-negative end of its subordinate group4 ,the difference between the two divisions is very great in ,groups ,,vi and ,,vii1 but it is extreme in ,group ,,viii1 where heavy metals are on one side and inactive gases on the other4 ,many authorities separate these gases into a 8,group ,o0 by themselves at the left-hand side of the table1 but this does not change their relative positions1 and the plan may be objected to on the ground that many vacant places are thus left in the groups ,,viii and ,o4 ,the periodic law has been useful in rectifying certain atomic weights4 ,at the outset ,mendeleff was obliged to change beryllium from #ade 7assuming ,be#b,o#c7 to #i 7assuming ,be,o71 and later the atomic weights of indium and uranium were changed to make them fit the system4 ,all of these changes have been confirmed by physical means4 ,mendeleff found a number of vacant places in his table1 and was thus able to render further service to chemical science by predicting the properties of undiscovered elements1 and his predictions were very closely confirmed by the later discovery of scandium1 gallium1 and germanium4 ,the table indicates that there are still two undiscovered elements below manganese and probably two more among the rare-earth metals4 ,the interesting observation has just recently been made by ,soddy that the products of radioactive disintegration appear to pass in a symmetrical way through positions in the periodic system1 giving off a helium molecule at alternate transformations until the place of lead is reached4 ,it appears1 therefore1 that the five vacant places in the table above bismuth are probably occupied by these evanescent elements1 and it is to be noticed that all of the elements that have been placed in this region of high atomic weights are radioactive4 ,there are some inconsistencies in the periodic system4 ,the increments in the atomic weights are irregular1 and there are three cases1 argon and potassium1 cobalt and nickel1 and tellurium and iodine1 where a higher atomic weight is placed before a lower one in order to bring these elements into their undoubtedly proper places4 ,there is a peculiarity also in the heavy-metal division of ,group ,,viii1 where three similar elements occur in each of three places1 and where the usual periodicity appears to be suspended1 or nearly so1 in comparison with most of the other elements4 ,however1 there seems to be a still more remarkable case of this kind in ,group ,,iii1 where fourteen metals of the rare earths have been placed4 ,they are astonishingly similar in their chemical properties1 hence it seems necessary to assume that periodicity is suspended here throughout the wide range of atomic weights from #aci to #agd1 where no elements save these have been found4 ,several other interesting features of the table may be pointed out4 ,the chlorides and hydrides1 as indicated by the 8typical compounds10 show a regular progression in both directions towards ,group ,,iv4 7,where the type-formulas do not apply1 as far as is known1 to more than one or two elements1 they have been placed in parentheses in the table given here47 ,it is a striking fact that the acid-forming elements occur together in a definite part of the table1 and that the gases and other non-metallic elements1 except the inactive gases of ,group ,,viii1 occur in the same region4 ,atomic ,numbers4--,as the result of a spectroscopic study of the wave lengths or frequencies of the ,x-rays produced when cathode rays strike upon anticathodes composed of different elements1 ,moseley in #aiad discovered that whole numbers in a simple series can be attributed to the atoms4 ,these atomic numbers are3 #a for hydrogen1 #b for helium1 #c for lithium1 #d for beryllium1 and so on1 in the order in which the elements occur in ,mendeleff's periodic table1 and in the cases of argon and potassium1 cobalt and nickel1 and tellurium and iodine1 they follow the correct chemical order1 while the atomic weights do not4 ,they appear to indicate1 therefore1 an even more fundamental relation between the atoms than that shown by the atomic weights4 ,these numbers are now available for every element up to lead1 and they are particularly interesting in indicating1 on account of missing numbers1 the existence of two undiscovered elements in the manganese group1 and two more among the rare-earth metals1 in confirmation of the vacant places below lead in ,mendeleff's table4 ,the ,isolation of ,elements4--,in the year #ahah about #ec elements were recognized1 and since that time about #cj more have been discovered1 but the elements already known comprised the more common ones1 and nearly all of those which have been commercially important4 ,a few of them1 including beryllium1 aluminium1 silicon1 magnesium1 and fluorine1 were then known only in their compounds1 as they had not yet been isolated in the free condition4 ,berzelius in #ahbc prepared silicon1 a non-metallic element resembling carbon in many respects4 ,this element has recently been prepared on a rather large scale in electric furnaces at ,niagara ,falls1 and has been used for certain purposes in the form of castings4 ,whler created much sensation in #ahbg by isolating aluminium and finding it to be a very light1 strong and malleable metal1 stable in the air1 and of a silver-white color4 ,for a long time this metal was a comparative rarity1 being prepared by the reduction of aluminium chloride with metallic sodium2 but about #be years ago ,hall1 an ,american1 devised a method of preparing it by electrolyzing aluminium oxide dissolved in fused cryolite4 ,this process reduced the cost of aluminium to such an extent that it has now come into common use4 ,whler and ,bussy prepared beryllium in #ahbh1 and ,liebig and ,bussy did the same service for magnesium in #ahcj4 ,the latter metal has come to be of much practical importance1 both as a very powerful reducing agent in chemical operations1 and as an ingredient of flash-light powders and of mixtures used for fireworks4 ,it is also used in making certain light alloys4 ,after almost innumerable attempts to isolate fluorine1 during a period of nearly a century1 this was finally accomplished in #ahhf by ,moissan in ,france by the electrolysis of anhydrous hydrogen fluoride4 ,the free fluorine proved to be a gas of extraordinary chemical activity1 decomposing water at once with the formation of hydrogen fluoride and ozonized oxygen4 ,this fact explains the failure of many previous attempts to prepare it in the presence of water4 ,early ,discoveries of ,new ,elements4--,the remarkable activity of chemical research at the beginning of our period is illustrated by the fact that three new elements were discovered in #ahag4 ,in that year ,berzelius had discovered selenium1 ,arfvedson1 working in ,berzelius's laboratory had discovered the important alkali-metal lithium1 and ,stromeyer had discovered cadmium4 ,in #ahbf ,ballard in ,france discovered bromine in the mother-liquor from the crystallization of common salt from sea water4 ,bromine proved to be an unusually interesting element1 being the only non-metallic one that is liquid at ordinary temperatures1 and being strikingly intermediate in its properties between chlorine and iodine4 ,it has been obtained in large quantities from brines1 and is produced extensively in the ,united ,states4 ,the elementary substance and its compounds have found important applications in chemical operations1 while the bromides have been found valuable in medicine and silver bromide is very extensively used in photography4 ,in #ahbh ,berzelius discovered thorium4 ,the oxide of this metal has recently been employed extensively as the principal constituent of incandescent gas-mantles1 and the element has acquired particular importance from the fact that1 like uranium1 it is radioactive1 decomposing spontaneously into other elements4 ,vanadium had been encountered as early as #ahja by ,del ,rio1 who named it 8erythronium10 but a little later it was thought to be identical with chromium and was lost sight of for a while4 ,in #ahcj1 however1 it was re-discovered by1 and received its present name from ,sefstrm in ,sweden4 ,berzelius immediately made an extensive study of vanadium compounds1 but he gave them incorrect formulas and derived an incorrect atomic weight for the element1 because he mistook a lower oxide for the element itself4 ,roscoe in ,england in #ahfg isolated vanadium for the first time1 found the right atomic weight1 and gave correct formulas to its compounds4 ,vanadium is particularly interesting from the fact that it displays several valencies in its compounds1 many of which are highly colored4 ,it has found important use as an ingredient in very small proportions in certain 8special steels0 to which it imparts a high degree of resistance to rupture by repeated shocks4 ,columbium was discovered early in the nineteenth century in the mineral columbite from ,connecticut by ,hatchett1 an ,englishman1 who did not1 however1 obtain the pure oxide4 ,it was afterwards obtained by ,rose who named it niobium4 ,both names for the element are in use1 but the former has priority4 ,attention was called to this fact by an article in the ,journal by ,connell1 an ,englishman 7#ah1 #cib1 #ahed74 ,the ,platinum ,group of ,metals4--,in #ahed a new member of the platinum group of metals1 ruthenium1 was discovered by ,claus4 ,platinum had been discovered about the middle of the eighteenth century1 while its other rarer associates1 iridium1 osmium1 palladium1 and rhodium1 had been recognized in the very early years of the nineteenth century4 ,it was during the latter period that platinum ware began to be employed to a considerable extent in chemical operations1 and this use was greatly extended as time went on4 ,the discovery was made by ,phillips in #ahca that finely divided platinum by contact would bring about the combination of sulphur dioxide with atmospheric oxygen1 and this application during the past #bj years has become enormously important in the sulphuric acid industry1 while other important applications of platinum as a 8catalytic agent0 have also been made4 ,wolcott ,gibbs and ,carey ,lea have contributed perhaps more than any other recent chemists to a knowledge of the platinum metals4 ,carey ,lea 7#ch1 #ha1 #bdh1 #ahfd7 dealt chiefly with the separation of the metals from each other1 while ,gibbs's work 7#ca1 #fc1 #ahfa2 #cd1 #cda1 #ahfb7 included investigations of many of the compounds4 ,it may be mentioned that while platinum and its associates were formerly known only in the uncombined condition in nature1 the arsenide sperrylite1 ,pt,as#b1 was described by the late ,s4 ,l4 ,penfield1 and the senior writer of this chapter1 in articles published in the ,journal 7#cg1 #fg1 #ga1 #ahhi74 ,applications of the ,spectroscope4--,the discovery in certain mineral waters of the rare alkali-metals rubidium and csium by ,bunsen and ,kirchoff in #ahfa was in consequence of the application of spectroscopy by these same scientists a short time previously to the identification of elements imparting colors to the flame4 ,since that time the employment of the spectroscope for chemical purposes has been much extended1 as it has been used in the examination of light from electric sparks and arcs1 as well as from ,geissler tube discharges and from colored solutions4 ,the metals rubidium and csium are interesting in being closely analogous to potassium and in standing at the extreme electro-positive end of the series of known metals4 ,it should be noticed here that ,johnson and ,allen of our ,sheffield ,laboratory1 having obtained a good supply of rubidium and csium material from the lepidolite of ,hebron1 ,maine1 made some important researches upon these elements1 accounts of which were published in the ,journal 7#cd1 #cfg1 #ahfb2 #ce1 #id1 #ahfc74 ,they established the atomic weight of csium1 thus correcting ,bunsen's determination which was unsatisfactory on account of the small quantity and impurity of his material4 ,pollucite1 a mineral rich in csium1 which had been found in very small amount on the ,island of ,elba1 has more recently been obtained in large quantities--hundreds of pounds--at ,paris1 ,maine1 and its vicinity4 ,this ,american pollucite was first analyzed and identified by the senior writer of this article 7#da1 #bac1 #ahia71 and later 7#dc1 #ag1 #ahib et seq47 the results of many investigations on csium and rubidium compounds1 in which the junior writer played an important part1 carried out in ,sheffield ,laboratory1 were published in the ,journal4 ,the application of the spectroscope led to the discovery of thallium in #ahfa by ,crookes of ,england1 and to that of indium in #ahfc by ,reich and ,richter in ,germany4 ,both of these metals are extremely rare1 but they are of considerable theoretical interest4 ,thallium is particularly remarkable in showing resemblances in its different compounds to several groups of metals4 ,the spectroscope was employed again in connection with the discovery of gallium in #ahge by ,boisbaudran4 ,it is in the same periodic group as thallium and indium1 and it has a remarkably low melting point1 just above ordinary room-temperature4 ,it has been among the rarest of the rare elements1 but within two or three years a source of it has been found in the ,united ,states in certain residues from the refining of commercial zinc4 ,the recent issues of the ,journal 7#da1 #cea1 #aiaf2 #db1 #chi1 #aiaf7 show that ,browning and ,uhler of ,yale have availed themselves of this new material in order to make important chemical and physical researches upon this metal4 ,germanium4--,the discovery of germanium in the mineral argyrodite in #ahhf by ,winkler revealed a curious metal which gives a white sulphide that may be easily mistaken for sulphur and which is volatilized completely when its hydrochloric acid solution is evaporated1 so that it is evasive in analytical operations4 ,this element had been predicted with much accuracy by ,mendeleff1 and it is rather closely related to tin4 ,a few years after the discovery of germanium1 ,penfield published in the ,journal 7#df1 #ajg1 #ahic2 #dg1 #dea1 #ahid7 some analyses of argyrodite1 correcting the formula given by ,winkler to the mineral2 also he described canfieldite1 an analogous mineral from ,bolivia1 in which a large part of the germanium was replaced by tin4 ,the ,rare ,earths4--,before the year #ahah two rare earths1 the oxides of yttrium and cerium1 were known in an impure condition4 ,since that time about fourteen others have been discovered as associates of the first two4 ,the rare earths are peculiar from the fact that many of them are always found mixed together in the minerals containing them1 and also from the circumstance that most of them are remarkably similar in their chemical reactions and consequently exceedingly difficult to separate from each other4 ,in many cases multitudes of fractional precipitations or crystallizations are needed to obtain pure salts of a number of these metals4 ,the solutions of the salts of several of these elements give characteristic absorption bands when examined spectroscopically by the use of transmitted light4 ,no important practical application has been found for any of these earthy oxides1 except that about one per cent of cerium oxide is mixed with thorium oxide in incandescent gas-mantles in order to obtain greatly increased luminosity4 ,the ,inactive ,gases4--,as long ago as #aghe1 ,cavendish1 that remarkable ,englishman who first weighed the world and first discovered the composition of water1 actually obtained a little argon in a pure condition by sparking atmospheric nitrogen with oxygen converting it into nitric acid 7another discovery of his7 and absorbing the excess of oxygen4 ,the volume of this residual gas as estimated by him corresponds very closely to the volume of argon in the atmosphere1 as now known4 ,it was more than a century later1 in #ahid1 that ,rayleigh and ,ramsay discovered argon in the air4 ,lord ,rayleigh had found that atmospheric nitrogen was about one-half per cent heavier than chemical nitrogen1 a fact which led to the investigation4 ,it was only necessary to repeat ,cavendish's experiment on a large scale1 or to absorb oxygen with hot copper and nitrogen with hot magnesium1 in order to obtain argon4 ,the gas attracted much attention1 both on account of having but a single atom in its molecule1 and particularly because it failed to enter into chemical combination of any kind4 ,this gas has been used of late for filling the bulbs of incandescent electric lamps in cases where a gas pressure without chemical action is desired4 ,in #ahij and #ahia1 ,hillebrand published in the ,journal 7#dj1 #chd1 #ahij3 #db1 #cij1 #ahia7 a series of analyses of the mineral uraninite and reported in some samples of the mineral as much as #be per cent of an inactive gas4 ,hillebrand examined the gas spectroscopically but1 just missing an important discovery1 he detected only the spectrum lines of nitrogen4 ,ramsay1 in searching for argon in some sort of natural combination1 and doubtless remembering ,hillebrand's work1 heated some cleveite1 a variety of uraninite1 and obtained1 not argon1 but a new gas4 ,this gave a yellow spectrum-line corresponding to a line previously observed in the light of the sun's corona and attributed to an element in the sun called helium4 ,helium1 therefore1 in #ahie had been found on the earth4 ,this gas is a constant constituent of uranium minerals1 as it is produced by the breaking down of radioactive elements4 ,it has been found in very small quantity in the atmosphere1 and is the most difficult of all known gases to liquefy1 as its boiling point1 as shown by ,onnes in #aijh1 is only #d above the absolute zero4 ,it has not yet been solidified4 ,in #ahih ,ramsay and ,travers1 by the use of ingenious methods of fractional distillation and absorption by charcoal1 obtained three other much rarer inactive gases from the atmosphere which they called neon1 krypton and xenon4 ,the inactive gases are all colorless1 and as they form no chemical compounds they are characterized by their densities1 which give their atomic weights1 by their boiling points1 and by their characteristic ,geissler-tube spectra4 ,the gaseous radium emanation1 or niton1 belongs also to the inactive group1 and it was also collected and studied by ,ramsay who was compelled to work with only #jjjja cc4 of it1 as the volume obtained by heating radium salts is very small4 ,it is an evanescent element1 disappearing within a few days on account of radioactive disintegration4 ,meanwhile it glows brilliantly when liquefied and cooled to the temperature of liquid air4 ,it has an atomic weight of #bbb1 four units below that of radium1 and the difference is considered as due to the loss by radium of an atom of helium in passing into the emanation4 ,the ,radioactive ,elements4--,the discovery of radium in #ahih by ,madame ,curie1 and the study of that and other radioactive elements has produced a profound effect upon chemical theory4 ,it was found that the two elements of the highest atomic weights1 uranium and thorium1 are always spontaneously decomposing into other elements at a fixed rate of speed which can be controlled by no artificial means1 and that the elements resulting from these decompositions likewise undergo spontaneous changes into still other elements at greatly varying rates of speed1 forming in each case a remarkable series of temporary elements4 ,these transformations are accompanied by the emission at enormous velocities of three kinds of rays1 one variety of which has been shown to consist of helium atoms4 ,the greater number of the elements formed in these transformations have not as yet been obtained in a pure condition1 and they are known only in connection with their radioactivity1 volatility1 etc42 but radium and niton1 two of these products1 have been obtained in a pure condition1 so that their atomic weights and their places in the periodic system have been fixed4 ,we owe much of our knowledge of the radioactive transformations to the researches of ,rutherford and of ,soddy1 and of their co-workers1 but one of the important products of the transformation of uranium1 an element which he called ionium1 was characterized by ,boltwood of ,yale 7#be1 #cfe1 #aijh74 ,radium and niton1 apart from their radioactive properties1 resemble barium and the inert gases of the atmosphere1 respectively4 ,the rates at which their progenitors produce them1 and the rates at which they themselves decompose1 bring about a state of equilibrium after a time4 ,therefore a given amount of uranium1 which decomposes exceedingly slowly1 can yield even after thousands of years only a very small proportional quantity of undecomposed radium1 one-half of which disappears in about #bejj years1 because the amount decomposed must eventually be equal to the amount produced4 ,the first conclusive evidence that radium is a product of the decomposition of uranium was given by ,boltwood in the ,journal 7#ah1 #ig1 #aijd74 ,he found that all uranium minerals contain radium2 and the amount of radium present is always proportional to the amount of uranium1 which shows the genetic relation between the two4 ,in the case of niton1 which is produced by radium1 and is called also the radium emanation1 the rate of decay is rapid1 so that if the gas is expelled from radium by heating1 equilibrium is reached after a few days1 with the accumulation of the largest possible amount of niton4 ,the conclusion has been reached by ,rutherford and others that the final product besides helium1 in the radioactive transformations1 is lead1 or at least an element or elements resembling lead to such a degree that no separation of them by chemical means is possible4 ,atomic weight determinations by ,richards and others have shown that specimens of lead found in radioactive minerals give distinctly different atomic weights from that of ordinary lead4 ,this fact has led to the view that possibly the atoms of the elements are not all of the same weight1 but vary within certain limits--a view that is contrary to previous conclusions derived from the uniformity in atomic weights obtained with material from many different sources4 ,the results of the investigations upon radioactivity have led to modified views in regard to the stability of the elements in general4 ,there has been little or no proof obtained that any artificial transmutation of the elements is possible1 but the spontaneous transformation of the radioactive elements brings forward the possibility that other elements are changing imperceptibly1 and that a state of evolution exists among them4 ,all of the radioactive changes that we know proceed from higher to lower atomic weights1 and we are entirely ignorant of the process by which uranium and thorium must have been produced originally4 ,since radioactive changes have been found to be accompanied by the release of vast amounts of energy1 compared with which the energy of chemical reactions is trivial1 a new aspect in regard to the structure of atoms has arisen1--they must be complex in structure1 the seats of enormous energy4 ,the determination of the amount of radium in the earth's crust has indicated that the heat produced by it is amply sufficient to supply the loss of heat due to radiation1 and this source of heat is regarded by many as the cause of volcanic action4 ,the sun's radiant heat also has been supposed to be supplied by radioactive action1 so that the older views regarding the limitation of the age of the earth and the solar system on account of loss of heat have been considerably modified by our knowledge of radioactivity4 ,physical ,chemistry4 ,the application of physical methods as aids to chemical science began in early times1 and some of these1 such as the determinations of gas and vapor densities1 specific heats1 and crystalline forms have been mentioned already in this article4 ,within recent times physical chemistry has greatly developed and a few of its important achievements will now be described4 ,molecular ,weight ,determinations4--,gas and vapor densities in connection with ,avogadro's principle1 formed the only basis for molecular weight determinations until comparatively recent times4 ,the early methods of ,gay-,lussac and ,dumas for vapor density were supplemented in #ahfh by the method of ,hofmann1 whereby vapors were measured under diminished pressure over mercury4 ,in #ahgh ,victor ,meyer introduced a simpler method depending upon the displacement of air or other gas by the vapor in a heated tube4 ,as refractory tubes1 such as those of porcelain or even iridium1 could be used in this method1 molecular weights at extremely high temperatures were determined with interesting results4 ,for instance1 it was found that iodine vapor1 which shows the molecule ,i#b at lower temperatures1 gradually becomes monatomic with rise in temperature1 that sulphur vapor dissociates from ,s#h to ,s#b under similar conditions1 and that most of the metals1 including silver1 have monatomic vapors4 ,in #ahhc and later it was pointed out by ,raoult that the molecular weights of substances could be found from the freezing points of their solutions1 but this method was complicated from the fact that salts1 strong acids and strong bases behaved quite differently from other substances in this respect1 and allowances had to be made for the types of substances used4 ,the complication was afterwards explained by the ionization theory of ,arrhenius4 ,better apparatus for this method was soon devised by ,beckmann1 who introduced also a method depending upon the boiling points of solutions1 and these two methods are still the standard ones for determining molecular weights in solution4 ,they are very extensively employed by organic chemists4 ,it has been found that the majority of substances when dissolved have the same molecular weight as in the gaseous condition1 provided that they can be volatilized at comparable temperatures4 ,for instance1 sulphur in solution has the formula ,s#h1 iodine is ,i#b and the metals are monatomic4 ,van't ,hoff's ,law and ,arrhenius's ,theory of ,ions4--,modern views on solutions date largely from #ahhf1 when van't ,hoff called attention to the relations existing between the osmotic pressure exerted by dissolved substances and gas pressure4 ,pfeffer1 a botanist1 was the first to measure osmotic pressure 7#ahgg74 ,basing his conclusions chiefly upon ,pfeffer's determinations1 van't ,hoff formulated a new and highly important law1 which may be stated as follows3 ,the osmotic pressure exerted by a substance in solution is equal to the gas pressure that the substance would exert if it were a gas at the same temperature and the same volume4 ,further investigations have fully established the fact that molecules in dilute solution obey the simple laws of gases4 ,it was pointed out by van't ,hoff that salts1 strong acids and strong bases showed marked exceptions to his law in exerting much greater osmotic pressures than those calculated for them4 ,the next year in #ahhg1 ,arrhenius explained this abnormal behavior of salts1 strong acids and strong bases by assuming that they dissociate spontaneously into ions when they dissolve1 and that these more numerous particles act like molecules in producing osmotic pressure4 ,he showed that these exceptional substances all conduct electricity in solution1 while those conforming with van't ,hoff's law do not1 and according to his theory the ions become positively or negatively charged when they are formed1 and these charged ions conduct the current4 ,for example a molecule of sodium chloride was supposed to give the two ions ,na and ,cl-1 thus exerting twice as much osmotic pressure as a single molecule4 ,determinations of osmotic pressure or related values1 such as depression of the freezing point and of electric conductivity1 indicated that ionization could not be regarded as complete in any case except in exceedingly dilute solutions1 and that the extent of ionization varied with different substances4 ,the fact that osmotic pressures and electric conductivities gave closely agreeing results in regard to the extent of ionization in various cases1 is the strongest evidence in support of the theory4 ,it was difficult at first for many chemists to believe that atoms1 such as those of sodium and chlorine1 and groups such as ,,nh#d and ,,so#d could exist independently in solution1 even though electrically charged4 ,however1 the theory rapidly gained ground and is now accepted by nearly every chemist as a satisfactory explanation of many facts4 ,during recent years1 many investigations relating to osmotic pressure and ionization have been carried out in the ,united ,states1 but only the work of ,morse1 ,a4 ,a4 ,noyes1 and the late ,h4 ,c4 ,jones can be merely alluded to here4 ,it should be mentioned that the eminent author of the ionic hypothesis gave the ,silliman ,memorial course of lectures at ,yale in #aiaa on ,theories of ,solution4 ,colloidal ,solutions4--,graham1 an ,english chemist1 in #ahfa was the first to make a distinction between substances forming true solutions1 which he called crystalloids1 and those of a gummy nature resembling glue1 which in solution do not diffuse readily through parchment membranes1 as crystalloids do1 and which he called colloids4 ,the separation of colloids by means of parchment was called dialysis1 and this process has come into extensive use in preparing pure colloidal solutions4 ,slow diffusion is now regarded as characteristic of colloids rather than their gummy condition4 ,colloidal solutions occupy an intermediate position between true solutions and suspensions1 resembling one or the other according to the kind of colloid and the fineness of division4 ,by preparing filters with pores of varying degrees of fineness1 ,bechold has been able to separate colloids from each other in accordance with the size of their particles4 ,it has also been possible to prepare different solutions of a colloid varying gradually from one in which the particles were undoubtedly in suspension to one which had many of the properties of a true solution4 ,beginning in #ahhi1 ,carey ,lea described in the ,journal 7#cg1 #dgf1 #ahhi et seq47 a variety of methods for preparing colloidal solutions of the metals1 consisting in general of treating solutions of metallic salts with mild reducing agents4 ,his work on colloidal silver was particularly extensive and interesting4 ,solutions of this kind have recently yielded some extremely interesting results by means of the ultra-microscope1 an apparatus devised by ,zsigmondy and ,siedentopf4 ,a very intense beam of light is passed through the solution and observed at right angles with a powerful microscope4 ,under these conditions1 particles much too small to be seen by other means1 reveal their presence by reflected light4 ,it has been possible in a very dilute solution of known strength to count the particles and thus to calculate their size4 ,the smallest colloidal particles measured in this way were of gold and were shown to have approximately ten times the diameter1 or #ajjj times the volume1 attributed to ordinary molecules4 ,it is of interest that the particles appear in rapid motion corresponding to the well-known ,brownian movement4 ,the chemistry of colloids has now assumed such importance that it may be considered as a separate branch of the science4 ,it has its own technical journal and deals largely with the chemistry of organic products4 ,all living matter is built up of colloids1 and hmoglobin1 starch1 proteins1 rubber and milk are examples of colloidal substances or solutions4 ,among inorganic substances1 many sulphides1 silicic acid1 and the amorphous hydroxides1 like ferric hydroxide1 frequently act as colloids4 ,law of ,mass ,action4--,berthollet about the beginning of the last century was the first chemist to study the effect of mass1 or more correctly1 the concentration of substances on chemical action4 ,his views summarized by himself are as follows3 8,the chemical activity of a substance depends upon the force of its affinity and upon the mass which is present in a given volume40 ,the development of this idea1 which is fundamentally correct1 was greatly hindered by the fact that ,berthollet drew the incorrect conclusion that the composition of chemical compounds depended upon the masses of the substances combining to produce them1 a conclusion in direct contradiction to the law of definite proportions1 and since this view was soon disproved by ,proust and others1 ,berthollet's law in its other applications received no immediate attention4 ,mitchell1 however1 pointed out in the ,journal 7#af1 #bcd1 #ahbi7 the importance of ,berthollet's work1 and ,heinrich ,rose in #ahdb again called attention to the effect of mass1 mentioning as one illustration the effect of water and carbonic acid in decomposing the very stable natural silicates4 ,somewhat later several other chemists made important contributions to the question of the influence of concentration upon chemical action1 but it was the ,norwegians1 ,guldberg and ,waage1 who first formulated the law of mass action in #ahfg4 ,this law has been of enormous importance in chemical theory1 since it explains a great many facts upon a mathematical basis4 ,it applies particularly to equilibrium in reversible reactions1 where it states that the product of the concentrations on the one side of a simple reversible equation bears a constant relation to the products of the concentrations on the other side1 provided that the temperature remains constant4 ,in cases of this kind where two gases or vapors react with two solids1 the latter if always in excess may be regarded as constant in concentration1 and the law takes on a simpler aspect in applying only to the concentrations of the gaseous substances4 ,for example1 in the reversible reaction #c;,fe #d;,h#b,o ,fe#c,o#d #d;,h#b1 which takes place at rather high temperatures1 a definite mixture of steam and hydrogen at a definite temperature will cause the reaction to proceed with equal rapidity in both directions1 thus maintaining a state of equilibrium1 provided that both iron and the oxide are present in excess4 ,if1 however1 the relative concentrations of the hydrogen and steam are changed1 or even if the temperature is changed1 the reaction will proceed faster in one direction than in the other until equilibrium is again attained4 ,the principle of mass action also explains why it is sometimes possible for a reversible reaction to become complete in either direction4 ,for instance1 in connection with the reaction that has just been considered1 if steam is passed over heated iron and if hydrogen is passed over the heated oxide1 the gaseous product in each case is gradually carried away1 and the reaction continually proceeds faster in one direction than in the other until it is complete1 according to the equations #c;,fe #d;,h#b,o #c;,fe#c,o#d #d;,h#b1 and ,fe#c,o#d #d;,h#b #c;,fe #d;,h#b,o4 ,many other well-known and important facts1 both chemical and physical1 depend upon this law4 ,it explains the circumstance that a vapor-pressure is not dependent upon the amount of the liquid that is present2 it also explains the constant dissociation pressure of calcium carbonate at a given temperature1 irrespective of the amounts of carbonate and oxide present2 in connection with the ionic theory1 it furnishes the reason for the variable solubility of salts due to the presence of electrolytes containing ions in common2 and it elucidates ,henry's law which states that the solubilities of gases are proportional to their pressures4 ,ostwald1 more than any other chemist1 has been instrumental in making general applications of this law1 and he made particularly extensive use of it in connection with analytical chemistry in a book upon this subject which he published4 ,the ,phase ,rule4--,in #ahgf ,willard ,gibbs of ,yale published a paper in the ,proceedings of the ,connecticut ,academy of ,science on the 8,equilibrium of ,heterogeneous ,substances10 and two years later he published an abstract of the article in the ,journal 7#af1 #dda1 #ahgh74 ,he had discovered a new law of nature of momentous importance and wide application which is called the 8,phase-,rule0 and is expressed by a very simple formula4 ,the application of this great discovery to chemical theory was delayed for ten years1 partly1 perhaps1 because it was not sufficiently brought to the attention of chemists1 but largely it appears because it was not at first understood1 since its presentation was entirely mathematical4 ,it was ,rooseboom1 a ,dutch chemist1 who first applied the phase-rule4 ,it soon attracted profound attention1 and the name of ,willard ,gibbs attained world-wide fame among chemists4 ,when ,nernst1 who is perhaps the most eminent physical chemist of the present time1 was delivering the ,silliman ,memorial ,lectures at ,yale a few years ago1 he took occasion to place a wreath on the grave of ,willard ,gibbs in recognition of his achievements4 ,to understand the rule1 it is necessary to define the three terms1 introduced by ,gibbs1 phase1 degrees of freedom and component4 ,by the first term1 is meant the parts of any system of substances which are mechanically separable4 ,for instance1 water in contact with its vapor has two phases1 while a solution of salt and water is composed of but one4 ,the degrees of freedom are the number of physical conditions1 including pressure1 temperature and concentration1 which can be varied independently in a system without destroying a phase4 ,the exact definition of a component is not so simple1 but in general1 the components of a system are the integral parts of which it is composed4 ,any system made up of the compound ,h#b,o1 for instance1 whether as ice1 water or vapor1 contains but one component1 while a solution of salt and water contains two4 ,letting ,p1 ,f1 and ,c stand for the three terms1 the phase-rule is simply ,f ,c #b ,p that is1 the number of degrees of freedom in a system in equilibrium equals the number of components1 plus two1 minus the number of phases4 ,the rule can be easily understood by means of a simple illustration4 ,in a system composed of ice1 water and water vapor1 there are three phases and one component and therefore ,f #a #b #c #j ,such a system has no degrees of freedom4 ,this means that no physical condition1 pressure or temperature can be varied without destroying a phase1 so that such a system can only exist in equilibrium at one fixed temperature1 with a fixed value for its vapor-pressure4 ,illustration3 ,j4 ,william ,gibbs ,for instance1 if the system is heated above the fixed temperature1 ice disappears and if the pressure is raised1 vapor is condensed4 ,if this same system of water alone contains but two phases1 for instance1 liquid and vapor1 ,f #a #b #b #a1 or there is one degree of freedom4 ,in such a system1 one physical condition such as temperature can be varied independently1 but only one1 without destroying a phase4 ,for instance1 the temperature may be raised or lowered1 but for every value of temperature there is a corresponding value for the vapor-pressure4 ,one is a function of the other4 ,if both values are varied independently1 one phase will disappear1 either vapor condensing entirely to water or the reverse4 ,finally if the system consists of one phase only1 as water vapor1 ,f #b1 or the system is divariant1 which means that at any given temperature it is possible for vapor to exist at varying pressures4 ,the illustration which has been given relates to physical equilibrium1 but the rule is applicable to cases involving chemical changes as well4 ,in comparing the phase-rule with the law of mass action1 it will be noticed that both have to do with equilibrium4 ,the great advantage of the former is that it is entirely independent of the molecular condition of the substances in the different phases4 ,for instance1 it makes no difference so far as the application of the rule is concerned1 whether a substance in solution is dissociated1 undissociated or combined with the solvent4 ,in any case1 the solution constitutes one phase4 ,on the other hand1 the rule is purely qualitative1 giving information only as to whether a given change in conditions is possible4 ,the law of mass action is a quantitative expression so that when the value of the constant is once known1 the change can be calculated which takes place in the entire system if the concentration of one substance is varied4 ,the law1 however1 requires a knowledge of the molecular condition of the reacting substances1 which may be uncertain or unknown1 and chiefly on this account it has1 like the phase-rule1 often only a qualitative significance4 ,the phase rule has served as a most valuable means of classifying systems in equilibrium and as a guide in determining the possible conditions under which such systems can exist4 ,as illustrations of its practical application1 van't ,hoff used it as an underlying principle in his investigations on the conditions under which salt deposits have been formed in nature1 and ,rooseboom was able by its means to explain the very complicated relations existing in the alloys of iron and carbon which form the various grades of wrought iron1 steel and cast iron4 ,thermochemistry4--,this branch of chemistry has to do with heat evolved or absorbed in chemical reactions4 ,it is important chiefly because in many cases it furnishes the only measure we have of the energy changes involved in reactions4 ,to a great extent1 it dates from the discovery by ,hess in #ahdj of a fundamental law which states that the heat evolved in a reaction is the same whether it takes place in one or in several stages4 ,this law has made it possible to calculate the heat values of a large number of reactions which cannot be determined by direct experiment4 ,thermochemistry has been developed by a comparatively few men who have contributed a surprisingly large number of results4 ,favre and ,silbermann1 beginning shortly after #ahej1 improved the apparatus for calorimetric determinations1 which is called the calorimeter1 and published many results4 ,at about the same time ,julius ,thomsen1 and in #ahgc ,berthelot1 began their remarkable series of publications which continued until recently4 ,thomsen's investigations were published in #ahhb in #d volumes4 ,it is probably safe to say that the greater part of the data of thermochemistry was obtained by these two investigators4 ,the bomb calorimeter1 an apparatus for determining heat values by direct combustion1 was developed by ,berthelot4 ,the recent work of ,mixter at ,yale1 published in the ,journal1 and of ,richards at ,harvard should be mentioned particularly4 ,mixter's work in this field began in #aija 7#ab1 #cdg74 ,using an improved bomb calorimeter1 he has developed a method of determining the heats of formation of oxides by combustion with sodium peroxide4 ,by this same method as well as by direct combustion in oxygen1 he has obtained results which appear to equal or excel in accuracy any which have ever been obtained in his field of work4 ,richards's work has consisted largely of improvements in apparatus4 ,he developed the so-called adiabatic calorimeter which practically eliminates one of the chief errors in thermal work caused by the heating or cooling effect of the surroundings4 ,this modification is being generally adopted where extremely accurate work is required4 ,organic ,chemistry4 ,one hundred years ago qualitative tests for a few organic compounds were known1 the elements usually occurring in them were recognized1 and some of them had been analyzed quantitatively1 but organic chemistry was far less advanced than inorganic1 and almost the whole of its enormous development has taken place during our period4 ,berzelius made a great advance in the subject by establishing the fact1 which had been doubted previously1 that the elements in organic compounds are combined in constant1 definite proportions4 ,in #ahbc ,liebig brought to light the exceedingly important fact of isomerism by showing that silver fulminate had the same percentage composition as silver cyanate1 a compound of very different properties4 ,isomeric compounds with identical molecular weight as well as the same composition have since been found in very many cases1 and they have played a most important part in determining the arrangements of atoms in molecules4 ,they have been found to be very numerous in many cases4 ,for instance1 three pentanes with the formula ,c#e;,h#ab;are known1 all that are possible according to theory1 and in each case the structure of the molecule has been established4 ,on theoretical grounds it has been calculated that #hjb isomeric compounds with the formula ,c#ac;,h#bh are possible1 while with more complex formulas the numbers of isomers may be very much greater4 ,a particularly interesting case of isomerism was observed by ,whler in #ahbh1 when he found that ammonium cyanate changes spontaneously into urea 7,,nh#d;,,cno ,n#b;,h#d;,,co74 ,this was the first synthesis of an organic compound from inorganic material1 and it overthrew the prevailing view that vital forces were essential in the formation of organic substances4 ,a great many natural organic compounds have been made artificially since that time1 and some of them1 such as artificial alizarin1 indigo1 oil of wintergreen1 and vanillin1 have more or less fully replaced the natural products4 ,the preparation of a vast number of compounds not known in nature1 many of which are of practical importance as medicines1 dyes1 explosives1 etc41 has been another great achievement of organic chemistry4 ,the development of our present formulas for organic compounds1 by means of which in many cases the relative positions of the atoms can be shown with the greatest confidence1 has been gradual4 ,formulas based on the dualistic idea of ,berzelius were used for some time1 type-formulas1 with the employment of compound radicals1 came later1 the substitution of atoms or groups of atoms for others in chemical reactions came to be recognized1 but one of the most important steps was the recognition of the quadrivalence of carbon and the general application of valency to atoms by ,kekul about #aheh4 ,this led directly to the use of modern structural formulas which have been of the greatest value in the theoretical interpretation of organic reactions4 ,it was ,kekul also who proposed the hexagonal ring-formula for benzene1 ,c#f;,h#f1 which led to exceedingly important theoretical and practical developments4 ,the details of the formulas for many other rings and complex structures have been established since that time1 and there is no doubt that the remarkable achievements in organic chemistry during the past sixty years have been much facilitated by the use of these formulas4 ,many important researches in organic chemistry have been carried out in the ,united ,states1 and the activity in this direction has greatly increased in recent years4 ,in this connection the large amount of work of this kind accomplished in the ,sheffield ,laboratory1 at present under the guidance of ,professor ,t4 ,b4 ,johnson1 should be mentioned4 ,it has happened that comparatively few publications on organic chemistry have appeared in the ,journal1 but it may be stated that the preparation of chloroform and its physiological effects were described by ,guthrie 7#ba1 #fd1 #ahcb74 ,unknown to him1 it had been prepared by ,souberain1 a ,french chemist1 the previous year1 but the former was the first to describe its physiological action4 ,silliman gave a sample to ,doctor ,eli ,ives of the ,yale ,medical ,school1 who used it to relieve a case of asthma4 ,this was the first use of chloroform in medical practice 7#ba1 #dje1 #ahcb74 ,guthrie also described in the ,journal 7#ba1 #bhd1 #ahcb7 his new process for converting potato starch into glucose1 a method which is essentially the same as that used to-day in converting cornstarch into glucose4 ,lawrence ,smith 7#dc1 #cja1 #ahdb et seq471 ,horsford 7#c1 #cfi1 #ahdg et seq471 ,sterry ,hunt 7#g1 #cii1 #ahdi71 ,carey ,lea 7#bf1 #cgi1 #aheh et seq471 ,remsen 7#e1 #agi1 #ahgc et seq471 and others have contributed articles on organic chemistry4 ,agricultural ,chemistry4 ,until near the middle of the nineteenth century1 it was believed that plants1 like animals1 used organic matter for food1 and depended chiefly upon the humus of the soil for their growth4 ,this view was held even long after it was known that plant leaves absorb carbon dioxide and give off oxygen1 and after the ashes of plants had been accurately analyzed4 ,this incorrect view was overthrown by the celebrated ,german chemist1 ,liebig1 who made many investigations upon the subject1 and1 properly interpreting previous knowledge1 published a book in #ahdj upon the application of chemistry to agriculture and physiology in which he maintained that the nutritive materials of all green plants are inorganic substances1 namely1 carbon dioxide1 water1 ammonia 7nitrates71 sulphates1 phosphates1 silica1 lime1 magnesia1 potash1 iron1 and sometimes common salt4 ,he drew the vastly important conclusion that the effective fertilization of soils depends upon replenishing the inorganic substances that have been exhausted by the crops4 ,the fundamental principles set forth by ,liebig have been confirmed1 and it has been found that the fertilizing constituents most commonly lacking in soils are nitrogen compounds1 phosphates1 and potassium salts1 so that these have formed the important constituents of artificial fertilizers4 ,liebig himself found that humus is valuable in soils1 because it absorbs and retains the soluble salts4 ,the foundation established by ,liebig in regard to artificial fertilizers has led to an enormous application of these materials1 much to the advantage of the world's food supply4 ,it was ,liebig's belief1 in accordance with the prevailing views1 that decay and putrefaction as well as alcoholic and other fermentations were spontaneous processes1 and when the eminent ,french chemist1 ,pasteur1 in #aheg1 explained fermentation as directly caused by yeast1 an epoch-making discovery which led to the explanation of decay and putrefaction by bacterial action and to the germ-theory of disease1 the explanation was violently opposed by ,liebig and other ,german chemists4 ,pasteur's view prevailed1 however1 and since that time it has been found that various kinds of bacteria are responsible for the formation of ammonia from nitrogenous organic matter and also for the change of ammonia into the nitrates that are available as plant-food4 ,the long-debated question as to the availability of atmospheric nitrogen for plant-food was settled in #ahhf by the discovery of ,hellriegel that bacteria contained in nodules on the roots1 especially of leguminous plants1 are capable of bringing nitrogen into combination and furnishing it to the plants4 ,no more than an allusion can be made to agricultural experiment stations where soils1 fertilizers1 foods and other products are examined1 and where other problems connected with agriculture are studied4 ,the late ,s4 ,w4 ,johnson of ,yale studied with ,liebig and subsequently did much service for agricultural chemistry in this country1 by his investigations1 his teaching1 and his writings4 ,his book1 8,how ,crops ,grow10 published in #ahfh1 gave an excellent account of the principles of agricultural chemistry4 ,he did much to bring about the establishment of agricultural experiment stations in this country1 and for a long time he was the director of the ,connecticut ,station4 ,in the ,journal1 as early as #ahbg1 ,amos ,eaton 7#ab1 #cgj7 published a simple method for the mechanical analysis of soils to determine their suitability for wheat-culture1 and ,hilgard1 between #ahgb and #ahgd1 described an elaborate study of soil-analysis4 ,j4 ,p4 ,norton1 a ,yale professor1 in #ahdg 7#c1 #cbb7 published an investigation on the analysis of the oat1 which was awarded a prize of fifty sovereigns by a ,scotch agricultural society1 while ,johnson1 ,atwater1 and others have contributed articles on the analysis of various farm products4 ,industrial ,acids and ,alkalies4 ,one hundred years ago sulphuric acid was manufactured on a comparatively very small scale in lead chambers4 ,in #ahah1 an ,english manufacturer of the acid introduced the modern feature of using pyrites in the place of brimstone1 while the ,gay-,lussac tower in #ahbg and the ,glover tower in #ahei began to be applied as great improvements in the chamber process4 ,within about twenty years the contact process1 employing platinized asbestos1 has replaced the old chamber process to a large extent4 ,it has the advantage of producing the concentrated acid1 or the fuming acid1 directly4 ,during our period the manufacture of sulphuric acid has increased enormously4 ,very large quantities of it have been used in connection with the ,leblanc soda process in its rapid development4 ,it came to be employed extensively for absorbing ammonia in the illuminating-gas industry1 which was in its infancy one hundred years ago4 ,new industries such as the manufacture of 8superphosphates0 as artificial fertilizers1 the refining of petroleum1 the manufacture of artificial dyestuffs and many other modern chemical products have greatly increased the demand for it1 while its employment in the production of nitric and other acids1 and for many other purposes not already mentioned1 has been very great4 ,the manufacture of nitric acid has been greatly extended during our period on account of its employment for producing explosives1 artificial dyestuffs1 and for many other purposes4 ,chile saltpeter became available for making it about #aheb4 ,this acid has been manufactured recently from atmospheric nitrogen and oxygen by combining them by the aid of powerful electric discharges4 ,this process has been used chiefly in ,norway where water-power is abundant1 as it requires a large expenditure of energy4 ,a still more recent method for the production of nitric acid depends upon the oxidation of ammonia by air with the aid of a contact substance1 such as platinized asbestos4 ,the production of ammonia1 which was very small a hundred years ago1 has been vastly increased in connection with the development of the illuminating-gas industry and the employment of by-product coke ovens4 ,this substance is very extensively used in refrigerating machines and also in a great many chemical operations1 including the ,solvay soda process4 ,ammonium salts are of great importance also as fertilizers in agriculture4 ,the conversion of atmospheric nitrogen into ammonia on a commercial scale is a recent achievement4 ,it has been accomplished by heating calcium carbide1 an electric-furnace product made from lime and coke1 with nitrogen gas1 thus producing calcium cyanamide1 and then treating this cyanamide with water under proper conditions4 ,another method devised by ,haber consists in directly combining nitrogen and hydrogen gases under high pressure with the aid of a contact substance4 ,leblanc's method for obtaining sodium carbonate from sodium chloride by first converting the latter into the sulphate by means of sulphuric acid and then heating the sulphate with lime and coal in a furnace was invented as early as #agia1 but it was not rapidly developed and did not gain a foothold in ,england until #ahbf on account of a high duty on salt up to that time4 ,afterwards the process flourished greatly in connection with the sulphuric acid industry upon which it depended1 and with the bleaching-powder industry which utilized the hydrochloric acid incidentally produced by it1 and1 of course1 in connection with soap manufacture and many other industries in which the soda itself was employed4 ,about #ahff the ,solvay process appeared as a rival to the ,leblanc process4 ,this depends upon the precipitation of sodium bicarbonate from salt solutions by means of carbon dioxide and ammonia1 with the subsequent recovery of the ammonia4 ,it has displaced the older process to a large extent1 and it is carried on extensively in this country1 for instance1 at ,syracuse1 ,new ,york4 ,other processes for soda depend upon the electrolysis of sodium chloride solutions4 ,in this case caustic soda and chlorine are the direct products1 and the chlorine thus produced and liquefied by pressure in steel cylinders1 has become an important commercial article4 ,in earlier times wood-ashes were the source of potash and potassium salts4 ,wurtz in the ,journal 7#aj1 #cbf1 #ahej7 suggested the availability of ,new ,jersey greensand as a source of potash and showed how this mineral could be decomposed1 but it does not appear that this mineral has ever been utilized for the purpose4 ,about #ahfa the ,german potash-salt deposits began to be developed1 and these have since become the chief source of this material4 ,at present many efforts are being made to obtain potassium compounds from other sources1 such as brines1 cement-kiln dust1 and feldspar and other minerals but thus far the results have not satisfied the demand4 ,conclusion4 ,this account of chemical progress has given only a limited view of small portions of the subject1 because the amount of available material is so vast in comparison with the space allowed for its presentation4 ,since the ,journal has published comparatively little organic chemistry1 it was decided to make room for a better presentation of other things by giving only a brief discussion of this exceedingly active and important branch of the science4 ,for similar reasons industrial and metallurgical chemistry1 and other branches besides1 in spite of their great growth and importance1 have been neglected1 except for some incidental references to them1 and some account of a few of the more important industrial chemicals4 ,it appears that we have much reason to be proud of the advances in chemistry that have been made during the ,journal's period1 and of the part that the ,journal has taken in connection with them1 and there seems to be no doubt that this progress has not diminished during more recent times4 ,the present tendency of chemical research is evidently towards a still greater development of organic chemistry1 and an increased application of physics and mathematics to chemical theory and practice4 ,the very great improvements that have been made in chemical education1 both in the number of students and the quality of instruction1 during the period under discussion1 and particularly in rather recent times1 gives promise for excellent future progress4 ,note4 ,footnote #aec3 ,it appears that the most accurate experimental demonstration ever made of this law was that of ,e4 ,w4 ,morley1 published in the ,journal 7#da1 #bbj1 #bgf1 #ahia74 ,he showed that #bjjjb volumes of hydrogen combine with one volume of oxygen4 ,,xi ,a ,,century',s ,,progress ,,in ,,physics ,by ,,leigh ,,page ,dynamics4--,at the beginning of the nineteenth century mechanics was the only major branch of physical science which had attained any considerable degree of development4 ,two centuries earlier1 ,galileo's experiments on the rate of fall of iron balls dropped from the top of the ,leaning ,tower of ,pisa1 had marked the origin of dynamics4 ,he had easily disproved the prevalent idea that even under conditions where air resistance is negligible heavy bodies would fall more rapidly than light ones1 and further experiments had led him to conclude that the increase in velocity is proportional to the time elapsed1 and not to the distance traversed1 as he had at first supposed4 ,less than a century later ,newton had formulated the laws of motion in the same words in which they are given to-day4 ,these laws of motion1 coupled with his discovery of the law of universal gravitation1 had enabled him to correlate at once the planetary notions which had proved so puzzling to his predecessors4 ,his success gave a tremendous stimulus to the development and extension of the fundamental dynamical principles that he had brought to light1 which culminated in the work of the great ,french mathematicians1 ,lagrange and ,laplace1 a little over a hundred years ago4 ,newton's laws of motion1 it must be remembered1 apply only to a particle1 or to those bodies which can be treated as particles in the problem under consideration4 ,in his 8,mcanique ,analytique0 ,lagrange extended these principles so as to make it possible to treat the motion of a connected system by a method almost as simple as that contained in the second law of motion4 ,instead of three scalar equations for each of the innumerably large number of particles involved1 he showed how to reduce the ordinary dynamical equations to a number equal to that of the degrees of freedom of the system4 ,this is made possible by a combination of d',alembert's principle1 which eliminates the forces due to the connections between the particles1 and the principle of virtual work1 which confines the number of equations to the number of possible independent displacements4 ,the aim of ,lagrange was to make dynamics into a branch of analysis1 and his success may be inferred from the fact that not a single diagram or geometrical figure is to be found in his great work4 ,celestial ,mechanics4--,almost simultaneously with the publication of the 8,mcanique ,analytique0 appeared ,laplace's 8,mcanique ,celeste40 ,laplace's avowed aim was to offer a complete solution of the great dynamical problem involved in the solar system1 taking into account1 in addition to the effect of the sun's gravitational field1 those perturbations in the motion of each planet caused by the approach and recession of its neighbors4 ,so successful was his analysis of planetary motions that his contemporaries believed that they were not far from a complete explanation of the world on mechanical principles4 ,laplace himself was undoubtedly convinced that nothing was needed beyond a knowledge of the masses1 positions1 and initial velocities of every material particle in the universe in order to completely predetermine all subsequent motion4 ,the greatest triumph of these dynamical methods was to come half a century later4 ,the planet ,uranus1 discovered in #agha by the elder ,herschel1 was at that time the farthest known planet from the sun4 ,but the orbit of ,uranus was subject to some puzzling variations4 ,after sifting all the known causes of these disturbances1 ,leverrier in ,france and ,adams in ,england independently reached the conclusion that another planet still more remote from the sun must be responsible1 and computed its orbit4 ,leverrier communicated to ,galle of ,berlin the results of his calculations1 and during the next few days the ,german astronomer discovered ,neptune within one degree of its predicted position6 ,illustration3 ,h4 ,a4 ,newton ,we shall mention but one other achievement of the methods of celestial mechanics4 ,those visitors of the skies1 the comets1 which become so prominent only to fade away and vanish perhaps forever1 had interested astronomers from the earliest times4 ,soon after the discovery of the law of gravitation1 ,newton had worked out a method by which the elements of a comet's orbit can be computed from observations of its position4 ,it was found that the great majority of these bodies move in nearly parabolic paths and only a few in ellipses4 ,of the latter the most prominent is the brilliant comet first observed by ,halley in #afha4 ,it has reappeared regularly at intervals of seventy-six years2 the last appearance in the spring of #aiaj is no doubt well remembered by the reader4 ,kant had considered comets to be formed by condensing solar nebul1 whereas ,laplace had maintained that they originate in matter which is scattered throughout stellar space and has no connection with the solar system4 ,a study of the distribution of inclinations of comet orbits by ,h4 ,a4 ,newton 7#af1 #afe1 #ahgh7 of ,new ,haven substantiated ,laplace's hypothesis1 and led to the conclusion that the periodic comets have been captured by the attraction of those planets near to which they have passed4 ,of these comets a number have comparatively short periods1 and are found to have orbits which are in general only slightly inclined to those of the planets1 and are traversed in the same direction4 ,moreover1 the fact that the orbit of each of these comets comes very close to that of ,jupiter made it seem probable that they have been attached to the solar system by the attraction of this planet4 ,further confirmation of this hypothesis was furnished by ,h4 ,a4 ,newton's 7#db1 #ahc and #dhb1 #ahia7 explanation of the small inclination of their orbits and the scarcity of retrograde motions among them4 ,in #ahcc occurred one of the greatest meteoric showers of history4 ,olmstead 7#bf1 #acb1 #ahcd7 and ,twining 7#bf1 #cbj1 #ahcd7 of ,new ,haven noticed that these shooting stars traverse parallel paths1 and were the first to suggest that they must be moving in swarms in a permanent orbit4 ,from an examination of all accessible records1 ,h4 ,a4 ,newton 7#cg1 #cgg1 #ahfd2 #ch1 #ec1 #ahfd7 was able to show that meteoric showers are common in ,november1 and of particular intensity at intervals of #cc or #cd years4 ,he confidently predicted a great shower for ,nov4 #acth1 #ahff1 which not only actually occurred but was followed by another a year later1 showing that the meteoric swarm extended so far as to require two years to cross the earth's orbit4 ,h4 ,a4 ,newton 7#cf1 #a1 #ahhh7 in ,america and ,adams in ,england took up the study of meteoric orbits with great interest1 and the former concluded that these orbits are in every sense similar to those of the periodic comets1 implying that a swarm of meteors originates in the disintegration of a comet4 ,in fact ,schiaparelli actually identified the orbit of the ,perseids1 or ,august meteors1 with ,tuttle's comet of #ahfb1 and shortly after the orbit of the ,leonids1 or ,november meteors1 was found to be the same as that of ,tempel's comet4 ,electromagnetism4--,during the eighteenth century much interest had been manifested in the study of electrostatics and magnetism4 ,du ,fay1 ,cavendish1 ,michell and ,coulomb abroad and ,franklin in ,america had subjected to experimental investigation many of the phenomena of one or both of these sciences1 and in the early years of the nineteenth century ,poisson developed to a remarkable extent the analytical consequences of the law of force which experiment had revealed4 ,both ,laplace and he made much use of the function to which ,green gave the name 8potential0 in #ahbh1 and which is such a powerful aid in solving problems involving magnetism or electricity at rest4 ,meantime electric currents had been brought under the hand of the experimenter by the discoveries of ,galvani and ,volta4 ,large numbers of cells were connected in series1 and interest seemed to lie largely in producing brilliant sparks or fusing metals by means of a heavy current4 ,hare 7#c1 #aje1 #ahba7 of the ,university of ,pennsylvania constructed a battery consisting of two troughs of forty cells each1 so arranged that the coppers and zincs can be lowered simultaneously into the acid and large currents obtained before polarization has a chance to interfere4 ,this 8deflagrator0 was used to ignite charcoal in the circuit1 or melt fine wires1 and was for some time the most powerful arrangement of its kind4 ,that 8galvanism0 is something quite different from static electricity was the opinion of many investigators2 ,hare considered the heat developed to be the distinguishing mark of the electric current4 ,he says3 8,it is admitted that the action of the galvanic fluid is upon or between atoms2 while mechanical electricity when uncoerced1 acts only upon masses4 ,this difference has not been explained unless by my hypothesis1 in which caloric1 of which the influence is only exerted between atoms1 is supposed to be a principal agent in galvanism40 ,questioning minds were beginning to suspect that there must be some connection between electricity and magnetism4 ,for lightning had been known to make magnets of steel knives and forks1 and ,franklin had magnetized a sewing needle by the discharge from a ,leyden jar4 ,finally ,oersted of ,copenhagen undertook systematic investigation of the effect of electricity on the magnetic needle4 ,his researches were without result until during the course of a series of lectures on 8,electricity1 ,galvanism1 and ,magnetism0 delivered during the winter of #ahai-bj it occurred to him to investigate the action of an electric current on a magnetic needle4 ,at first he placed the wire bearing the current at right angles to the needle1 with1 of course1 no result2 then it occurred to him to place it parallel4 ,a deflection was observed1 for to his surprise the needle insisted on turning until perpendicular to the wire4 ,oersted's discovery that an electric current exerts a couple on a magnetic needle was followed a few months later by ,ampre's demonstration before the ,french ,academy that two currents flowing in the same direction attract each other1 while two in opposite directions repel4 ,the story goes that a critic attempted to belittle this discovery by remarking that as it was known that two currents act on one and the same magnet1 it was obvious that they would act upon each other4 ,whereupon ,arago arose to defend his friend4 ,drawing two keys out of his pocket he said1 8,each of these keys attracts a magnet2 do you believe that they therefore attract each other80 ,a few years later ,ampre showed how to express quantitatively the force between current elements1 and indeed developed to a considerable degree the equivalence between a closed circuit carrying a current and a magnetic shell4 ,so convincing was his analysis and so thorough his discussion of the subject1 that ,maxwell said of this memoir half a century later1 8,the whole1 theory and experiment1 seems as if it had leaped1 full grown and full armed1 from the brain of the #8,newton of electricity4' ,it is perfect in form and unassailable in accuracy2 and it is summed up in a formula from which all the phenomena may be deduced1 and which must always remain the cardinal formula of electrodynamics40 ,shortly afterwards the dependence of a current on the conductivity of the wire used and the grouping of cells employed1 was made clear by the work of ,ohm4 ,many of his results were obtained independently by ,joseph ,henry 7#ai1 #djj1 #ahca7 of the ,albany ,academy1 who described in #ahca a powerful electromagnet in which a great many coils of wire insulated with silk were wound around an iron core and connected in parallel with a single cell4 ,he remarks in this paper that with long wires1 as in the telegraph1 many cells arranged in series should be used1 whereas for several short wires connected in parallel a single cell with large plates is more efficient4 ,current ,induction4--,impressed by the fact that electric charges have the power of inducing other charges on neighboring conductors without coming into contact with them1 ,faraday was engaged in investigating the possibility of an analogous phenomenon in the case of electric currents4 ,his idea at first seems to have been that a current should induce another current in any closed conducting circuit which happens to be in its vicinity4 ,experiment readily showed the falsity of this conception1 but a brief deflection of the galvanometer in the secondary circuit was noticed at the instant of making and breaking the current in the primary4 ,further experiments showed that thrusting a permanent steel magnet into a coil connected to a galvanometer caused the needle to deflect4 ,in fact ,faraday's report to the ,royal ,society on ,november #bdth1 #ahca1 contains a complete account of all experimental methods available for inducing a current in a closed circuit4 ,while ,faraday is entitled to credit for the discovery of current induction by virtue of the priority of his publication1 it must not pass unnoticed that ,henry obtained many of the same experimental results independently and some even earlier4 ,henry was at this time instructor in mathematics at the ,albany ,academy1 and seven hours of teaching a day made it well nigh impossible to carry on original research except during the vacation month of ,august4 ,as early as the summer of #ahcj he had wound #cj feet of copper wire around the armature of a horseshoe electromagnet and connected it to a galvanometer4 ,when the magnet was excited1 a momentary deflection was observed4 8,i was1 however1 much surprised10 he says1 8to see the needle suddenly deflected from a state of rest to about #bj to the east1 or in a contrary direction1 when the battery was withdrawn from the acid1 and again deflected to the west when it was re-immersed40 ,in addition a deflection was obtained by detaching the armature from the magnet1 or by bringing it again into contact4 ,had the results of these experiments been published promptly1 ,america would have been entitled to credit for the most important discovery of the greatest of ,england's many great experimenters4 ,but ,henry desired first to repeat his experiments on a larger scale1 and while new magnets were being constructed1 the news of ,faraday's discovery arrived4 ,this occasioned hasty publication of the work already done in an appendix to volume #bb1 #ahcb1 of the ,journal4 ,at almost the same time ,henry made another important discovery and this time he was anticipated by no other investigator in making public his results4 ,in the paper already referred to be describes the phenomenon known to-day as self-induction4 8,when a small battery is moderately excited by diluted acid and its poles1 which must be terminated by cups of mercury1 are connected by a copper wire not more than a foot in length1 no spark is perceived when the connection is either formed or broken2 but if a wire thirty or forty feet long be used1 instead of the short wire1 though no spark will be perceptible when the connection is made1 yet when it is broken by drawing one end of the wire from its cup of mercury a vivid spark is produced4444 ,the effect appears somewhat increased by coiling the wire into a helix2 it seems to depend in some measure on the length and thickness of the wire2 ,i can account for these phenomena only by supposing the long wire to become charged with electricity which by its reaction on itself projects a spark when the connection is broken40 ,soon after1 ,henry went to ,princeton and there continued his experiments in electromagnetism4 ,no difficulty was experienced in inducing currents of the third1 fourth and fifth orders by using the first secondary as primary for yet another secondary circuit1 and so on 7#ch1 #bji1 #ahdj74 ,the directions of these currents of higher orders when the primary is made or broken proved puzzling at first1 but were satisfactorily explained a year later 7#da1 #aag1 #ahda74 ,in addition induced currents were obtained from a ,leyden jar discharge4 ,faraday failed to find any screening effect of a conducting cylinder placed around the primary and inside the secondary4 ,henry examined the matter1 and found that the screening effect exists only when the induced current is due to a make or break of the primary circuit1 and not when it is caused by motion of the primary4 ,henry's work was mainly descriptive2 it remained for ,faraday to develop a theory to account for the phenomena discovered and to prepare the way for quantitative formulation of the laws of current induction4 ,this he did in his representation of a magnetic field by means of lines of force2 a conception which he found afterwards to be equally valuable when applied to electrostatic problems4 ,every magnet and every current gives rise to these closed curves2 in the case of a magnet they thread it from south pole to north1 while a straight wire bearing a current is surrounded by concentric rings4 ,the connection between lines of force and the induction of currents is contained in the rule that a current is induced in a closed circuit only when a change takes place in the number of lines of force passing through it4 ,furthermore the dependence of the current strength on the conductivity of the wire employed has led to recognition of the fact that it is the electromotive force and not the current itself which is conditioned by the change in magnetic flux4 ,great interest was attached to the utilization of the newly discovered forces of electromagnetism4 ,in #ahca ,henry 7#bj1 #cdj1 #ahca7 described a reciprocating engine depending on magnetic attraction and repulsion1 and ,c4 ,g4 ,page 7#cc1 #aah1 #ahch2 #di1 #aca1 #ahde7 devised many others4 ,the latter's most important work1 however1 was the invention of the ,ruhmkorff coil4 ,in #ahcf 7#ca1 #acg1 #ahcg7 he found the strongest shocks to be obtained1 from a secondary coil of many windings forming a continuation of a primary of half the number of turns4 ,his perfection of the self-acting circuit breaker 7#ce1 #beb1 #ahci7 widened the usefulness of the induction coil1 and his substitution of a bundle of iron wires for a solid iron core 7#cd1 #afc1 #ahch7 greatly increased its efficiency4 ,conservation of ,energy4--,perhaps the most important advance of the nineteenth century has been the establishment of the principle of conservation of energy4 ,despite the fact that the 8principe de la conservation des force vives0 had been recognized by the ,french mathematicians of the early part of the century1 the application of this principle even to purely mechanical problems was contested by some scientists4 ,through the early numbers of the ,journal runs a lively controversy as to whether there is not a loss of power involved in imparting momentum to the reciprocating parts of a steam engine only to check the motion later on in the stroke4 ,finally ,isaac ,doolittle 7#ad1 #fj1 #ahbh71 of the ,bennington ,iron ,works1 ends the discussion by the pertinent remark3 8,if there be1 as is contended by one of your correspondents1 a loss of more than one third of the power1 in transforming an alternating rectilinear movement into a continuous circular one by means of a crank1 ,i should like to be informed what would be the effect if the proposition were reversed1 as in the case of the common saw mill1 and in many other instances in practical mechanics40 ,a realization of the equivalence of heat and mechanical work did not come until the middle of the century1 in spite of the conclusive experiments of the ,american ,count ,rumford and the ,english ,davy before the year #ahjj4 ,so firmly enthroned was the caloric theory1 according to which heat is an indestructible fluid1 that evidence against it was given scant consideration4 ,in fact the success of the analytical method introduced by ,fourier in #ahbb for the solution of problems in conduction of heat only added to the difficulties of the adherents of the kinetic theory4 ,but recognition of heat as a form of energy was on the way1 and when it came it made its appearance almost simultaneously in half a dozen different places4 ,perhaps ,robert ,mayer of ,heilbronn was the first to state explicitly the new principle4 ,his paper 8,on the ,forces of ,inorganic ,nature0 was refused publication in ,poggendorff's ,annalen1 but fared better at the hands of another editor4 ,during the next few years ,joule determined the mechanical equivalent of heat experimentally by a number of different methods1 some of which had already been devised by ,carnot4 ,of those he used1 the most familiar consists in churning up a measured mass of water by means of paddles actuated by falling weights and calculating the heat developed from the rise in temperature4 ,however1 the work of the young ,manchester brewer received little attention from the members of the ,british ,association before whom it was reported until ,kelvin showed them its significance and attracted their interest to it4 ,meanwhile ,helmholtz had completed a very thorough disquisition on the conservation of energy not only in dynamics and heat but in other departments of physics as well4 ,his paper on 8,die ,erhaltung der ,kraft0 was frowned upon by the members of the ,physical ,society of ,berlin before whom he read it1 and received the same treatment as ,mayer's from the editor of ,poggendorff's ,annalen4 ,helmholtz's 8,kraft10 like the 8vis viva0 of other writers1 is the quantity which ,young had already christened energy4 ,not many years elapsed1 however1 until the convictions of ,mayer1 ,joule1 ,kelvin and ,helmholtz became the most clearly recognized of all physical principles4 ,as early as #ahej ,jeremiah ,day 7#aj1 #agd1 #ahej71 late president of ,yale ,college1 admitted the improbability of constructing a machine capable of perpetual motion1 even though the 8imponderable agents0 of electricity1 galvanism and magnetism be utilized4 ,thermodynamics4--,the importance of the principle of conservation of energy lies in the fact that it unites under one rule such diverse phenomena as gravitation1 electromagnetism1 heat and chemical action4 ,another principle as universal in its scope1 although depending upon the coarseness of human observations for its validity rather than upon the immutable laws of nature1 was foreshadowed even before the first law of thermodynamics1 or principle of conservation of energy1 was clearly recognized4 ,this second law was the consequence of efforts to improve the efficiency of heat engines4 ,in #ahbd ,carnot introduced the conception of cyclic operations into the theory of such engines4 ,assuming the impossibility of perpetual motion1 he showed that no engine can have an efficiency greater than that of a reversible engine4 ,finally ,clausius expressed concisely the principle toward which ,carnot's work had been leading1 when he asserted that 8it is impossible for a self-acting machine1 unaided by any external agency1 to convey heat from one body to another at a higher temperature40 ,kelvin's formulation of the same law states that 8it is impossible1 by means of inanimate material agency1 to derive mechanical effect from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects40 ,the consequences of the second law were rapidly developed by ,kelvin1 ,clausius1 ,rankine1 ,barnard 7#af1 #bah1 #ahec1 et seq47 and others4 ,kelvin introduced the thermodynamic scale of temperature1 which he showed to be independent of such properties of matter as condition the size of the degree indicated by the mercury thermometer4 ,this scale1 which is equivalent to that of the ideal gas thermometer1 was used subsequently by ,rowland in his exhaustive determination of the mechanical equivalent of heat by an improved form of ,joule's method4 ,he found different values for different ranges in temperature1 showing that the specific heat of water is by no means constant4 ,since then electrical methods of measuring this important quantity have been used to confirm the results of purely mechanical determinations4 ,the definition of a new quantity1 entropy1 was found necessary for a mathematical formulation of the second law of thermodynamics4 ,this quantity1 which acts as a measure of the unavailability of heat energy1 was given a new significance when ,boltzmann showed its connection with the probability of the thermodynamic state of the substance under consideration4 ,if two bodies have widely different temperatures1 a large amount of the heat energy of the system is available for conversion into mechanical work4 ,from the macroscopic point of view this is expressed by saying that the entropy is small1 or if the motions of the individual molecules are taken into account1 the probability of the state is low4 ,the interpretation of entropy as the logarithm of the thermodynamic probability has thrown much light on the meaning of this rather abstruse quantity4 ,gibbs's 8,elementary ,principles in ,statistical ,mechanics0 treats in detail the fundamental assumptions involved in this point of view1 its limitations and its consequences4 ,in his 8,equilibrium of ,heterogeneous ,substances0#aed he had already extended the principle of thermal equilibrium to include substances which are no longer homogeneous4 ,the value of the chemical potential he introduced determines whether one phase is to gain at the expense of another or lose to it4 ,it is unfortunate that the analytical rigor and austerity of his reasoning combined with lack of mathematical training on the part of the average chemist1 delayed true appreciation of his work and full utilization of the new field which he opened up4 ,liquefaction of ,gases4--,meanwhile the problem of liquefying gases was attracting much attention on the part of experimental physicists4 ,faraday had succeeded in making liquid a number of substances which had hitherto been known only in the gaseous state4 ,his method consists in evolving the gas from chemicals placed in one end of a bent tube1 the other end of which is immersed in a freezing mixture4 ,the high pressure caused by the production of the gas combined with the low temperature is sufficient to bring about liquefaction in many cases4 ,failure with other more permanent gases was unexplained until the researches of ,andrews in #ahfc showed that no amount of pressure will produce liquefaction unless the temperature is below a certain critical value4 ,the method of reducing the temperature in use to-day depends on a fact discovered by ,kelvin and ,joule in connection with the free expansion of a gas4 ,these investigators allowed the gas to escape through a porous plug from a chamber in which the pressure was relatively high4 ,with the single exception of hydrogen1 the effect of the sudden expansion is to cool the gas1 and even with it cooling is found to take place after the temperature has been made sufficiently low4 ,by this method all known gases have been liquefied4 ,helium1 with a boiling point of -#bfi;,c1 or only #d;,c4 above the absolute zero1 was the last to be made a liquid1 finally yielding to the efforts of ,kammerlingh ,onnes in #aijg4 ,this investigator#aee finds that at temperatures near the absolute zero the electrical conductivity of certain substances undergoes a profound modification4 ,for example1 a coil of lead shows a superconductivity so great that a current once started in it persists for days after the electromotive force has ceased to act4 ,electrodynamics4--,faraday's representation of electric and magnetic fields by lines of force had been of great value in predicting the results of experiments in electromagnetism4 ,but a more mathematical formulation of the laws governing these phenomena was needed in order to make possible quantitative development of the theory4 ,this was supplied by ,maxwell in his epoch-making treatise on 8,electricity and ,magnetism40 ,starting with electrostatics and magnetism1 he gives a complete account of the mathematical methods which had been devised for the solution of problems in these branches of the subject1 and then turning to ,ampre's work he shows how the ,lagrangian equations of motion lead to ,faraday's law if the single assumption is made that the magnetic energy of the field is kinetic4 ,in the treatment of open circuits ,maxwell's intuition led to a great advance1 the introduction of the displacement current4 ,consider a charged condenser1 the plates of which are suddenly connected by a wire4 ,a current will flow through the wire from the positively charged plate to the negative1 but in the gap between the two plates the conduction current is missing4 ,so convinced was ,maxwell that currents must always flow in closed circuits1 that he postulated an electrical displacement in the medium between the plates of a charged condenser1 which disappears when the condenser is short-circuited4 ,thus even in the so-called open circuit the current flows along a closed path4 ,maxwell's theory of the electromagnetic field is based essentially on ,faraday's representation by lines of force of the strains and stresses of a universal medium4 ,so it is not surprising that he was led to a consideration of the propagation of waves through this medium4 ,the introduction of the displacement current made the form of the electrodynamic equations such as to yield a typical wave equation for space free from electrical charges and currents4 ,moreover1 the disturbance was found to be transverse1 and its velocity turned out to be identical with that of light4 ,the conclusion was irresistible4 ,that light could consist of anything but electromagnetic waves of extremely short length was inconceivable4 ,in fact so certain was ,maxwell of this deduction from theory that he felt it altogether unnecessary to resort to the test of experiment4 ,for the electromagnetic theory explained so many of the details which had been revealed by experiments in light1 that no doubt of its validity could be entertained4 ,even dispersion received ready elucidation on the assumption that the dispersing medium is made up of vibrators having a natural period comparable with that of the light passing through it4 ,illustration3 ,james ,clerk ,maxwell ,maxwell's book was published in #ahgc4 ,fifteen years later1 ,hertz1#aef at the instigation of ,helmholtz1 succeeded in detecting experimentally the electromagnetic waves predicted by ,maxwell's theory4 ,his oscillator consisted of two sheets of metal in the same plane1 to each of which was attached a short wire terminating in a knob4 ,the knobs were placed within a short distance of each other1 and connected to the terminals of an induction coil4 ,by reflection standing waves were formed1 and the positions of nodes and loops determined by a detector composed of a movable loop of wire containing an air gap4 ,thus the wave length was measured4 ,hertz calculated the frequency of his radiator from its dimensions1 and then computed the velocity of the disturbance4 ,in spite of an error in his calculations1 later pointed out by ,poincar1 he obtained very nearly the velocity of light for waves traveling through air1 but a velocity considerably smaller for those propagated along wires4 ,subsequent work by ,lecher1 ,sarasin and de la ,rive1 and ,trowbridge and ,duane 7#di1 #big1 #ahie2 #ej1 #ajd1 #ahie7 cleared up this discrepancy1 and showed the velocity to be in both cases identical with that of light4 ,the last-named investigators increased the size of the oscillator until it was possible to measure the frequency by photographing the spark in the secondary with a rotating mirror4 ,the positions of nodes and loops were obtained by means of a bolometer after the secondary had been tuned to resonance with the vibrator4 ,the velocity thus found for electromagnetic waves along wires is within one-tenth of one percent of the accepted value of the velocity of light4 ,hertz's later experiments showed that waves in air suffer refraction and diffraction1 and he succeeded in polarizing the radiation by passing it through a grating constructed of parallel metallic wires4 ,in order to satisfy the law of action and reaction1 it is found necessary to attribute a quasi-momentum to electromagnetic waves4 ,when a train of such waves is absorbed1 their momentum is transferred to the absorbing body1 while if they are reflected an impulse twice as great is imparted4 ,this consequence of theory1 foreseen by ,maxwell and developed in detail by ,poynting1 ,abraham and ,larmor1 has been verified by the experiments of ,lebedew1 and ,nichols and ,hull4#aeg ,the latter used a delicate torsion balance from which was suspended a couple of silvered glass vanes4 ,in order to eliminate the effect of impulses imparted by the molecules of the residual gas1 such as ,crookes had observed in his radiometer1 readings were made at many different pressures and the ballistic rather than the static deflection recorded4 ,after the pressure produced by light from a carbon arc had been measured1 the intensity of the radiation was determined with a bolometer4 ,preliminary experiments indicated the existence of a pressure of the order expected1 and later more careful measurements showed good quantitative agreement with theory4 ,this pressure had already found an important application in ,lebedew's explanation of the solar repulsion of comet's tails4 ,these tails are made up of enormous swarms of very minute particles1 and as the comet swings around the sun they suffer a repulsion due to the pressure of the intense solar radiation which counteracts the sun's gravitational attraction4 ,hence the tail1 instead of following after the comet in its orbit1 points in a direction away from the sun4 ,some uncertainty existed as to whether a convection current produces a magnetic field4 ,a compass needle is deflected by a current from a ,daniell cell2 is the same effect obtained when a conductor is charged electrostatically and then whirled around the needle by means of an insulating handle8 ,the experimental difficulties involved in settling this question are realized when the enormous difference between the electrostatic and electromagnetic units of current is taken into consideration4 ,for a sphere one centimeter in radius1 charged to a potential of #bj1jjj volts1 and revolving in a circle sixty times a second1 constitutes a current of little over a millionth of an ampere4 ,this problem was undertaken by ,rowland 7#ae1 #cj1 #ahgh7 in ,helmholtz's laboratory at ,berlin in #ahgf4 ,a hard rubber disk coated on both sides with gold was charged and rotated about a vertical axis at a rate of sixty revolutions a second4 ,on reversing the sign of the electrification on the disk1 the astatic needle hung above its center showed a deflection of over five millimeters4 ,the current was calculated in electrostatic units from the charge on the disk and its rate of motion1 and in electromagnetic units from the magnetic deflection4 ,the ratio of these two quantities gave fair agreement with its theoretical value1 the velocity of light4 ,although the result of this experiment was confirmed by ,rowland and ,hutchinson in #ahhi1 ,crmieu was convinced by an investigation carried out at ,paris in #aijj that the ,rowland effect did not exist4 ,consequently further repetition of the experiment was desirable4 ,so the following year ,adams 7#ab1 #aee1 #aija7 arranged two rings of eight spheres each so that they could be rotated about their common axis from fifty to sixty times a second4 ,one set of spheres was connected by brushes to the positive pole of a battery of #bj1jjj volts1 the other to the negative pole4 ,the deflection of a nearby magnetometer needle was observed when the electrification of the two rings was reversed1 and from the reading so obtained the ratio of the electromagnetic to the electrostatic unit of current computed4 ,this quantity was found to differ from the velocity of light by only a few percent4 ,this experiment and the even more exhaustive investigations carried out by ,pender1 both independently and in collaboration with ,crmieu1 finally convinced the scientific world that a convection current produces the same magnetic field as a conduction current of the same magnitude4 ,in discussing the ponderomotive force experienced in a magnetic field by a conductor through which a current is passing1 ,maxwell had said1 8,it must be carefully remembered1 that the mechanical force which urges a conductor carrying a current across the lines of magnetic force1 acts1 not on the electric current1 but on the conductor which carries it40 ,hall 7#ai1 #bjj1 #ahhj71 one of ,rowland's students1 questioned this statement1 and determined to put it to the test of experiment4 ,efforts to find an increase in the resistance of a wire placed at right angles to the lines of magnetic force were unsuccessful4 ,so the current was passed through a moderately broad strip of gold leaf and the effect of the magnetic field on the equipotential lines investigated4 ,the results obtained confirmed ,hall's belief that the force exerted by the field acts on the current itself1 and is transmitted through it to the conductor4 ,further investigation 7#bj1 #afa1 #ahhj7 revealed the same deflection of equipotential lines in thin strips of other metals1 although the effect was found to be reversed in iron4 ,during the closing years of the nineteenth century occurred three events of far reaching importance4 ,the electron was isolated1 and its charge and mass measured by ,j4 ,j4 ,thomson in ,england2 ,x-rays were discovered by ,rntgen in ,germany2 and the first indications of radioactivity were found by ,becquerel in ,france4 ,the first two are certainly to be attributed largely to the great advances which had been made in obtaining high vacua1 and the last two might not have occurred so soon had it not been for the photographic plate4 ,the ,electron4--,the atomic theory of electricity dates from the time of ,faraday4 ,his experiments on electrolysis showed that each monovalent atom or radical1 whatever its nature1 carries the same charge1 each bivalent ion a charge twice as great4 ,only a lack of knowledge of the number of atoms in a gram of the dissociated salt prevented him from calculating the value of the elementary charge4 ,as the discharge of electricity through gases at low pressures became a subject for experimental investigation1 another line of approach to the study of the atom of electricity was opened up4 ,as early as the seventies ,hittorf and ,goldstein had observed that a shadow is cast by a screen placed in front of the cathode of a ,crookes tube4 ,varley suggested that the cathode rays producing the shadow consist of 8attenuated particles of matter1 projected from the negative pole by electricity40 ,the discovery that these rays are deflected by a magnetic field led ,english physicists to the conclusion that they must be composed of charged particles1 and the direction of the deflection was such as to require the charge to be negative4 ,hertz contested this view on the ground that his experiments showed the rays to be unaffected by an electrostatic field1 and suggested that they consist of etherial disturbances4 ,finally ,perrin succeeded in passing the rays into a metal cylinder which received from them a negative charge1 and ,lenard showed how excessively minute these negatively charged particles must be by actually passing them through a thin sheet of aluminium in the wall of a vacuum tube1 and detecting their presence in the air outside4 ,conclusive information as to the nature of the electron1 as it was named by ,johnstone ,stoney1 was supplied by the classic experiments of ,j4 ,j4 ,thomson4#aeh ,first he showed that ,hertz's failure to find a deflection when a stream of electrons passes between the plates of a charged condenser was due to the screening effect of the gaseous ions produced by the discharge4 ,with a much more highly evacuated tube he found no difficulty in obtaining a deflection in an electrostatic field4 ,by using crossed electric and magnetic fields the deflection produced by one was just balanced by that caused by the other1 and from the field strengths employed both the velocity of the particles and the ratio 7e7_/7m7 of charge to mass was calculated4 ,the former was found to be about one-tenth the velocity of light1 but the most startling result of the experiment was that the same value of 7e7_/7m7 was obtained no matter what residual gas was contained in the tube or of what metal the cathode was made4 ,to calculate e and then m other methods are necessary4 ,c4 ,t4 ,r4 ,wilson has shown that in supersaturated air1 water drops form easily on charged molecules1 and that negative ions are more effective in causing condensation than positive ones4 ,by making use of the results of this research ,thomson has been able to measure the elementary charge4 ,for suppose a stream of negative ions to pass through supersaturated air4 ,a little drop forms on each charged particle1 and the cloud of condensed vapor settles to the bottom of the vessel4 ,the charge carried and the mass of water deposited can be measured directly4 ,stokes' law for the rate of fall of a minute particle through a gaseous medium enables the average size of the drops to be computed from the observed rate of descent of the cloud4 ,hence the number of drops formed and the charge carried by each follows at once4 ,h4 ,a4 ,wilson improved the method by noting the effect of an electric field upon the rate of fall of the charged drops1 and subsequent experiments undertaken by ,millikan#aei have been of such a character as to enable him to follow the motion of a single drop4 ,instead of water1 the latter uses oil drops less than one ten-thousandth of a centimeter in diameter4 ,a drop1 after one or more electrons have attached themselves to it1 is actually weighed in terms of the charge on its surface by applying an upward electric force just sufficient to balance the force of gravity4 ,then its weight is independently obtained from the density of the oil and the radius of the drop as determined by the rate of fall when the electric field is absent4 ,comparison of these two expressions gives #dggd7aj7-aj electrostatic units for the elementary charge4 ,combining this result with the value of 7e7_/7m7 found by ,thomson1 the mass of the electron comes out to be about one eighteen-hundredth that of an atom of the lightest known element1 hydrogen4 ,that the electron is a fundamental constituent of all matter is attested by the fact that charge and mass are the same regardless of the source or manner of production4 ,whether emitted by a heated metal1 under the action of ultra-violet light1 from a radioactive substance1 by a body exposed to ,x-rays1 as a result of friction1 it is the same negatively charged particle that constitutes the cathode ray of the discharge tube4 ,moreover1 it makes its effect felt indirectly in many other phenomena1 and from an investigation of some of these the ratio of charge to mass can be determined independently4 ,of such perhaps the most interesting is the ,zeeman effect4 ,spectroscopy4--,early in the nineteenth century ,fraunhofer had observed that the solar spectrum is crossed by a large number of dark lines4 ,their presence was unexplained until in #ahei ,kirchhoff and ,bunsen showed 8that a colored flame1 the spectrum of which contains bright sharp lines1 so weakens rays of the color of these lines when they pass through it1 that dark lines appear in place of bright lines as soon as there is placed behind the flame a light of sufficient intensity1 in which the lines are otherwise absent40 ,for intra-atomic oscillators must have the natural frequency of the radiation which they emit1 and consequently resonance will take place when they are exposed to rays of this frequency coming from an outside source1 and selective absorption ensue4 ,by comparing the bright lines in the spectra of metallic vapors made luminous by a gas flame with the dark lines in the sun's spectrum these investigators showed that many of the common terrestrial elements exist in the sun4 ,the interest in spectroscopy grew rapidly4 ,the excellent diffraction gratings made by ,rutherfurd were succeeded by the superior concave gratings of ,rowland4 ,in #ahgg ,draper 7#ad1 #hi1 #ahgg7 announced the discovery of the bright lines of oxygen in the solar spectrum1 but his interpretation of his photographs has not been corroborated by the work of later investigators4 ,langley 7#aa1 #dja1 #aija71 by the aid of his newly invented bolometer1 succeeded in detecting the emission of energy from the sun in the infra-red in amounts far exceeding that contained in the visible spectrum4 ,in #ahdb ,doppler drew attention to the fact that motion of the source should cause a displacement of the spectral lines1 the shift being to the blue if the light is approaching and to the red if it is receding1 and a few years later ,fizeau suggested the application of ,doppler's principle to the measurement of the velocity of a star moving in the line of sight4 ,thus the spectroscope has been able to supply one of the deficiencies of the telescope1 and the two together are sufficient to reveal all components of stellar motion4 ,when spectra formed by light from the sun's limb and from its center are compared1 the same effect reveals the rotation of the sun about its axis4 7,c4 ,s4 ,hastings1 #e1 #cfi1 #ahgc2 ,c4 ,a4 ,young1 #ab1 #cba1 #ahgf47 ,further ,evidence of the ,electron4--,in #ahde ,faraday discovered a rotation of the plane of polarization when light passes in the direction of the lines of force through a piece of glass placed between the poles of an electromagnet4 ,examination of the spectrum from a glowing vapor situated between the poles of a magnet1 however1 failed to reveal any effect of the field4 ,the latter problem was attacked anew by ,zeeman#afj in #ahif1 and with the aid of the improved appliances of modern science he succeeded in detecting a broadening of the lines4 ,later experiments with more powerful apparatus resolved these broadening lines into several components4 ,lorentz#afa showed at once how the electron theory furnishes an explanation of the ,zeeman effect4 ,he found that when the source is viewed at right angles to the lines of magnetic force1 a spectral line should be split into three components4 ,of these he predicted that the middle1 or undisplaced component1 would be found to be polarized at right angles to the direction of the field1 and the other components parallel to the field4 ,when the light proceeds from the source in a direction parallel to the magnetic lines of force1 two components only should be formed1 and these should be circularly polarized in opposite senses4 ,moreover1 from the separation of the components can be calculated the ratio of charge to mass of the electronic vibrator which is responsible for the emission of radiant energy4 ,zeeman's experiments confirmed ,lorentz's theory in every detail1 and yielded a value of 7e7_/7m7 in substantial agreement with that obtained for cathode rays4 ,subsequent research1 however1 has shown that in many cases more components are found than the elementary theory calls for4 ,hale has detected the ,zeeman effect in light from sun spots1 proving that these blemishes on the sun's face are vortices caused by whirling swarms of electrified particles4 ,recently ,stark and ,lo ,surdo have found a similar splitting up of lines in the spectrum formed by light from canal rays 7rays of positively charged particles7 passing through an intense electric field4 ,this phenomenon has as yet received no adequate explanation4 ,on discovering that an electric current is capable of producing a magnetic field1 ,ampre had suggested that the magnetic properties of such substances as iron might be explained on the assumption of molecular currents4 ,the electron theory considers these currents to be due to the revolution1 inside the atom1 of negatively charged particles about an attracting nucleus4 ,it occurred to ,richardson that this motion should give the atom the properties of a gyrostat4 ,hence if an iron bar be rotated about its axis1 the atoms should orient themselves so as to make their axes more nearly parallel to the axis of rotation4 ,thus its rotation should cause the bar to become a magnet4 ,barnett#afb has tested this hypothesis1 and has found the effect ,richardson had predicted4 ,from the strength of the magnetization produced1 the value of 7e7_/7m7 can be computed4 ,barnett finds a value somewhat smaller than that for cathode rays1 but of the right order of magnitude and sign4 ,einstein and ,de ,haas have detected the inverse of this effect1 i4 e41 the rotation of an iron rod when it is suddenly magnetized4 ,x-,rays4--,in #ahie1 on developing a plate which had been lying near a vacuum tube1 ,rntgen#afc was surprised to find distinct markings on it4 ,as the plate had never been exposed to light1 it was necessary to suppose the effect to be due to some new and unknown type of radiation4 ,further investigation showed that this radiation originates at the points where cathode rays impinge on the glass walls of the tube4 ,besides being able to pass with ease through all but the most dense material objects ,x-rays were found to have the power of ionizing gases through which they pass and ejecting electrons from metal surfaces against which they strike4 ,the points at which these electrons are produced are in turn the sources of secondary ,x-rays whose properties are characteristic of the metal from which they come4 ,rntgen's discovery excited intense interest among laymen as well as in scientific circles4 ,of the many ,x-ray photographs taken1 those of ,wright 7#a1 #bce1 #ahif7 of ,yale were the first to be produced in this country4 ,his experiments were made immediately on receipt of the news of ,rntgen's research1 and resulted in the publication of a number of photographs showing the translucency for these rays of paper1 wood1 and even aluminium4 ,as ,x-rays are undeviated by electric or magnetic fields1 ,schuster1 and later ,wiechert and ,stokes1 suggested that they might be electromagnetic waves of the same nature as light1 but much shorter and less regular4 ,the great objection to this hypothesis was the failure either to refract or diffract these rays4 ,in fact ,bragg contended that they were not etherial disturbances at all1 but consisted of neutral particles moving with very high velocities4 ,finally ,laue#afd demonstrated their undulatory nature by showing that diffraction took place under proper conditions4 ,just as the distance between adjacent lines of a grating must be comparable to the wave length of light for a spectrum to be formed1 a periodic structure with a grating space of their very much shorter wave length is necessary to diffract ,x-rays4 ,such a structure is altogether too fine to be made by human tools4 ,nature1 however1 has already prepared it for man's use4 ,the distance between the atoms of a crystal is just right to make it an excellent ,x-ray grating1 and ,laue had no difficulty in obtaining diffraction patterns when ,rntgen rays were passed through a block of zincblende4 ,the distance between adjacent atoms of this cubic crystal can be computed at once from its density and molecular weight1 and then the wave length of the radiation calculated from the deviation suffered4 ,in this way ,x-rays are found to have a length less than one thousandth as great as visible light4 ,further study of this phenomenon1 particularly by the two ,braggs1 father and son1 has revealed many of the structural details of more complicated crystals4 ,the most significant investigation in the field opened up by ,laue's discovery is that undertaken by ,moseley#afe only a couple of years before he lost his life in the trenches at ,gallipoli4 ,using many different metals as anticathodes in a vacuum tube1 he measured the frequencies of the characteristic rays emitted4 ,he found that if the elements are arranged in order of increasing atomic weight1 the square roots of the characteristic frequencies form an arithmetical progression4 ,if to each element is assigned an integer1 beginning with one for hydrogen1 two for helium1 and so on1 the square root of the frequency of the characteristic radiation is found to be proportional to this atomic number4 ,even though ,uhler has shown recently that over wide ranges ,moseley's law does not hold within the limits of experimental error1 there is undoubtedly much significance to be attached to this simple relation4 ,radioactivity4--,the year following the discovery of ,x-rays1 ,becquerel found that a photographic plate is similarly affected by radiations from uranium salts4 ,two years later the ,curies separated from pitchblende the very active elements polonium and radium4 ,passage of the rays from these substances through electric and magnetic fields revealed the existence of three types4 ,the alpha rays have been shown by ,rutherford and his co-workers to be positively charged helium atoms2 the beta rays are very rapidly moving electrons2 and the gamma rays are electromagnetic pulses of the same nature as ,x-rays but somewhat shorter4 ,in #aijb ,rutherford and ,soddy advanced the theory of atomic disintegration1 according to which the emission of a ray is an indication of the breaking down of the atom to a simpler form4 ,thus in the radioactive substances there is going on before our eyes a continual transformation of one element into another1 a change1 by the way1 which appears to be in no slightest degree either hastened or delayed by changes in temperature 7,h4 ,l4 ,bronson1 #bj1 #fj1 #aije7 or external electrical condition of the radioactive element4 ,uranium is the progenitor of a long line of descendants1 of which radium was supposed for some time to be the first member4 ,boltwood 7#be1 #cfe1 #aijh7 of ,yale1 however1 showed that the slow growth of radium in uranium solutions is incompatible with this assumption1 and soon isolated an intermediate product which he named ionium4 ,radium itself disintegrates into a gas known as radium emanation1 which in turn gives rise to a succession of other products4 ,analyses by ,boltwood 7#bc1 #gg1 #aijg7 of radioactive minerals from the same locality show such a constant ratio between the amounts of uranium and lead present that it is natural to conclude that lead is the end product of the series4 ,this hypothesis is confirmed by the fact that the oldest rocks show relatively the greatest amounts of this element4 ,in addition to the ,ionium-,radium series two others have been discovered4 ,of these ,boltwood's 7#be1 #bfi1 #aijh7 investigations seem to indicate that the one which starts with actinium is a collateral branch of the radium series and comes from the same parent uranium4 ,the other begins with thorium and comprises ten members4 ,as yet the end products of the actinium and thorium series have not been identified1 although there is some reason for believing that an isotope of lead may be the final member of the latter4 ,as the amount of a radioactive element which disintegrates in a given time is proportional to the total mass present1 an infinite time would be required for the substance to be completely transformed4 ,hence the life of such an element is measured by the half value period1 or time taken for half the initial mass to disintegrate4 ,this time varies widely for different radioactive substances1 ranging from a small fraction of a second for actinium ,a to five billion years for uranium4 ,boltwood's 7#be1 #dic1 #aijh7 original determination of the life of radium from the rate of its growth in a solution containing ionium gave #bjjj years as its result1 although recent measurements by ,miss ,gleditsch 7#da1 #aab1 #aiaf7 agree more closely with the value #agfj years obtained by ,rutherford and ,geiger from the number of alpha particles emitted4 ,under the action of ,x-rays or the radiations from radioactive substances1 gases acquire a conductivity which has been attributed by ,thomson and ,rutherford to the formation of ions4 ,zeleny has found that ions of opposite sign have somewhat different mobilities in an electric field1 and experiments of ,wellisch 7#ci1 #ehc1 #aiae7 show that at low pressures some of the negative ions are electrons4 ,t4 ,s4 ,taylor 7#bf1 #afi1 #aijh et seq47 and ,duane 7#bf1 #dfd1 #aijh7 have investigated the ionization produced by alpha particles1 and ,bumstead 7#cb1 #djc1 #aiaa et seq47 has studied the emission of electrons from metals which are bombarded by these rays4 ,the investigations of ,franck and ,hertz1 and ,mc,lennan and ,henderson1 show a significant relation between the ionizing potential 7energy which must be possessed by an electron in order to produce an ion on colliding with an atom7 and a quantity1 to be considered later in more detail1 which has been introduced by ,planck into the theory of radiation4 ,methods of ,science4--,scientific progress seems to follow a more or less clearly defined path4 ,experimentation brings to light the hidden processes of nature1 and hypotheses are advanced to correlate the facts discovered4 ,as more and more phenomena are found to fit into the same scheme1 the hypotheses at first proposed tentatively1 although often only after extensive alterations1 become firmly established as theories4 ,finally there may appear a fundamental clash between two theories1 each of which in its respective domain seems to represent the only possible manner in which a large group of phenomena can be correlated4 ,the maze becomes more perplexing at every step4 ,at last a genius appears on the scene1 approaches the problem from a new and unsuspected point of view1 and the paradox vanishes4 ,such changes in point of view are the milestones which mark the progress of science4 ,that science is stagnant whose only function is to collect1 classify and correlate vast stores of experimental data4 ,the sign of vitality is the existence of clearly defined and fundamental problems any possible solution of which seems irreconcilable with the most basic truths of the science in question4 ,the greater the paradox grows1 the more certain the advent of a new point of view which will bring one step nearer the comprehensive picture of nature which is the goal of natural philosophy4 ,the ,ether4--,from the earliest times philosophers have been attracted by the possibility of explaining physical phenomena in terms of an all-pervading medium4 ,so strong had this tendency become by the middle of the nineteenth century that the ,english school of physicists were attributing rigidity1 density and nearly all the properties of material media to the ether4 ,in fact most physicists seemed to have forgotten that no experiment had ever given direct evidence of the existence of such a medium4 ,not until the first decade of the twentieth century was it realized that the experimental evidence actually pointed in quite the opposite direction1 and that a new point of view was needed in dealing with those phenomena of light and electromagnetism which had been previously described in terms of a universal medium4 ,some account of the development of the ether theory and of the origin and growth of the point of view which has its principal exemplification in the principle of relativity is essential for an understanding of present tendencies in formulating a philosophic basis for scientific thought4 ,in the time of ,newton and for a century after there was much controversy between the adherents of two irreconcilable theories of light4 ,hooke had suggested that light is a wave motion traveling through a homogeneous medium which fills all space1 and ,huygens had shown that the law of refraction can be deduced at once from this hypothesis if it is assumed that the velocity of light in a transparent body is less than that in free ether4 ,however1 ,newton1 impressed by the fact that a ray obtained by double refraction in ,iceland spar differs from a ray of ordinary light just as a rod of rectangular cross section differs from one of circular cross section1 and seeing no way of explaining this dissymmetry in terms of a wave motion analogous to longitudinal sound waves1 adhered to the view that light consists of infinitesimal particles shot out from the luminous body with enormous velocities4 ,so great was his reputation on account of his discoveries in other fields that this theory of light held sway among his contemporaries and successors until the labors of ,young and ,fresnel at the beginning of the nineteenth century definitely established the undulatory theory4 ,however1 in spite of the fact that a corpuscular theory of light made the assumption of an ether unnecessary in so far as the simpler of the observed phenomena are concerned1 even ,newton postulated the existence of such a medium1 partly in order to explain the more complicated results of experiments in light1 and partly in order to provide a vehicle for the propagation of gravitational forces4 ,now an ether1 if it is to explain anything at all1 must have at least some of the simpler properties of material media4 ,the most fundamental of these1 perhaps1 is position in space4 ,as a first approximation in explaining optical phenomena on the earth's surface1 the earth might be supposed to be at rest relative to the ether4 ,but the establishment of the ,copernican system made the sun the center of the solar system and gave the earth an orbital speed of eighteen miles a second4 ,it may be remarked parenthetically that the speed of a point on the equator due to the earth's diurnal rotation is quite insignificant compared to its orbital velocity4 ,hence as a second approximation the sun might be considered at rest relative to the ether and the earth as moving through this unresisting medium4 ,the first indication of this motion lay in the discovery of aberration by the ,british astronomer ,bradley in #agbh4 ,bradley noticed that stars near the pole of the ecliptic describe small circles during the course of a year1 while those in the plane of the ecliptic vibrate back and forth in straight lines1 stars in intermediate positions describing ellipses4 ,the surprising thing1 however1 was that the time taken to complete one of these small orbits is in all cases exactly a year4 ,bradley concluded that the phenomenon is in some way dependent on the earth's motion around the sun1 and he was not long in reaching the correct explanation4 ,for suppose the earth to be at rest4 ,then in observing a star at the pole of the ecliptic it would be necessary to keep the axis of the telescope exactly at right angles to the plane of the earth's orbit4 ,however1 as the earth is in motion1 the telescope must be pointed a little forward1 just as in walking rapidly through the rain an umbrella must be inclined forward so as to intercept the raindrops which would otherwise fall on the spot to be occupied at the end of the next step4 ,the angle through which the telescope has to be tilted is known as the angle of aberration1 and the tangent of this angle may easily be shown to be equal to the ratio of the velocity of the earth to the velocity of light4 ,knowing the velocity of the earth1 the velocity of light can then be calculated4 ,this method was one of the first of obtaining the value of this important quantity4 ,more recently1 terrestrial methods of great precision have been devised for measuring the velocity of light4 ,the most accurate of these is that employed by the ,french physicist ,foucault in #ahfb4 ,a ray of light is reflected by a rotating mirror to a fixed mirror placed at some distance1 which in turn reflects the ray back to the moving mirror4 ,the latter1 however1 has turned through a small angle during the time elapsed since the first reflection1 and consequently the direction of the ray on returning to the source is not quite opposite to that in which it had started out4 ,this deviation in direction is determined from the displacement of the image formed by the returning light1 and from it the velocity of light is calculated4 ,in order to make the deflection appreciable the distance between the two mirrors should be very great4 ,as originally arranged by ,foucault1 it was found impractical to make this distance greater than twenty meters1 and consequently the displacement of the image was less than a millimeter4 ,such a small deflection limited the accuracy of the experiment to one percent4 ,in #ahgi1 however1 ,michelson 7#ah1 #cij1 #ahgi71 then a master in the ,united ,states ,navy1 improved ,foucault's optical arrangements to such an extent that he was able to use a distance of nearly seven hundred meters between the two mirrors4 ,with a rate of two hundred and fifty-seven revolutions a second for the rotating mirror1 the displacement obtained was over thirteen centimeters4 ,this experiment gave #bii1iaj kilometers a second for the velocity of light1 with a probable error of one part in ten thousand4 ,later investigations by ,newcomb and ,michelson 7#ca1 #fb1 #ahhf7 gave substantially the same result4 ,so great has been the accuracy of these terrestrial determinations that recent practice has been to calculate from them and the angle of aberration the earth's orbital velocity1 and hence the distance of the earth from the sun4 ,this indirect method of measuring the astronomical unit has a probable error no greater than the best parallax methods of the astronomer4 7,j4 ,lovering1 #cf1 #afa1 #ahfc47 ,aberration is a first order effect1 i4 e41 it depends upon the first power of the ratio of the velocity of the earth to the velocity of light1 and at first sight it seemed to prove conclusively that the earth must be in motion relative to the luminiferous medium4 ,other questions had to be settled1 however1 and one of these was whether or not light coming from a star would be refracted differently when passing through optical instruments from light which had a terrestial origin4 ,arago subjected the matter to experiment1 and concluded that in every respect the light from a star behaved as if the earth were at rest and the star actually occupied the position which it appears to occupy on account of aberration4 ,finally optical experiments with terrestrial sources seemed to be in no way affected by the motion of the earth through the ether4 ,in order to account for these facts ,fresnel advanced the following theory4 ,to explain the refraction that takes place when light enters a transparent body1 it is necessary to assume that light waves travel more slowly through matter than in free ether4 ,now the velocity of sound is known to vary inversely with the square root of the density of the material medium through which it passes4 ,hence it is natural to assume that ether is condensed inside material objects to such an extent that this same relation connects its density with the velocity of light traveling through it4 ,but when a lens or prism is set in motion1 ,fresnel supposed it to carry along only the excess ether which it contains1 ether of the normal density remaining behind4 ,this assumption suffices to explain ,arago's results1 and yet fits in with the phenomenon of aberration4 ,it gives for light traveling in the direction of motion through a moving material medium of index of refraction n an absolute velocity greater than that when the medium is at rest by an amount 7#a 7#a_/n#b77v1 which is only a fraction of the velocity v which would have to be added if convected matter carried along all the ether which resides within it4 ,this expression was tested directly1 first by ,fizeau in #ahea1 and later by ,michelson and ,morley 7#ca1 #cgg1 #ahhf7 in this country4 ,the experiment consists in bifurcating a beam of light1 passing one-half in one direction and the other in the opposite direction through a stream of running water4 ,on reuniting the two rays the usual interference fringes are produced4 ,reversing the direction of motion of the water causes the fringes to shift1 and from the amount of this shift the velocity imparted to the light by the motion of the stream is computed4 ,the divergence between the experimental value of this quantity and that calculated from ,fresnel's coefficient of entrainment was found by ,michelson and ,morley to be less than one percent1 which was about their experimental error4 ,thus ,fresnel's expression for the velocity of light in a moving medium is entirely confirmed by experiment4 ,the derivation of it accepted to-day1 however1 is very different from his original deduction4 ,it has been noted that the phenomena of polarization led ,newton to reject the wave theory of light4 ,the only type of wave known to him was the longitudinal wave1 in which the vibrations of the particles of the medium are in the same direction as that of propagation of the wave1 and it was impossible to suppose that such a wave could have different properties in different directions at right angles to the line in which it is advancing4 ,but in #ahag ,young suggested that this inconsistency between the wave theory and the facts of polarization could be removed by supposing the vibrations constituting light to be executed at right angles to the direction of propagation4 ,thus in ordinary light the vibrations are to be conceived as taking place haphazard in all directions in the plane perpendicular to the ray1 while in plane polarized light these vibrations are confined to a single direction4 ,this supposition explained so many of the puzzling results of experiment1 that it was accepted at once and led to the complete vindication of the undulatory theory4 ,elastic ,solid ,theory4--,shortly afterwards ,poisson succeeded in solving the differential equation which determines the motion of a wave through an elastic medium4 ,his solution shows that such a medium is capable of transmitting two types of wave--one longitudinal1 the other transverse4 ,if denotes the volume elasticity1 the rigidity and the density of the medium1 the velocities of the two waves are respectively 77 777_/7 and 7_/7 ,now a solid has both compressibility and rigidity1 and transmits in general both types of wave4 ,a fluid1 on the other hand1 on account of its lack of rigidity1 cannot support a transverse vibration4 ,hence it was natural that ,green1 in searching for a dynamical explanation of the ether1 should have proposed in a paper read before the ,cambridge ,philosophical ,society in #ahcg that the ether has the elastic properties of a solid4 ,one great difficulty presented itself2 disturbances inside an elastic solid must give rise to compressional as well as to transverse waves4 ,but no such thing as a compressional wave had been found in the experimental study of light4 ,green attempted to overcome this difficulty by attributing an infinite volume elasticity to the ether4 ,the expression above shows that longitudinal waves originating in such an incompressible medium would be carried away with an infinite velocity1 and it may be shown that the energy associated with them would be infinitesimal in amount4 ,the next step was to calculate the coefficients of transmission and reflection for light passing from one material medium to another4 ,here the elastic solid theory is not altogether successful4 ,if the ether is supposed to have different densities in the two media1 as in ,fresnel's theory1 but the same rigidity1 certain of these coefficients fail to give the values demanded by experiment1 while if the densities are assumed the same but the rigidities different1 other of the coefficients have discordant values4 ,in connection with the phenomena of double refraction even more serious difficulties are encountered4 ,electromagnetic ,theory4--,it was beginning to be felt that an ether must explain more than the phenomena of light1 for ,faraday's conception of electromagnetic action as carried on through the agency of a medium had added greatly to its functions4 ,finally ,maxwell's demonstration that electromagnetic waves are propagated with the velocity of light made the theory of light into a subdivision of electrodynamics4 ,maxwell himself did not apply electromagnetic theory to the explanation of reflection and refraction4 ,this deficiency1 however1 was remedied by ,lorentz in #ahge4 ,the results obtained1 as well as those for double refraction 7,j4 ,w4 ,gibbs1 #bc1 #bfb1 #ahhb et seq471 and metallic reflection 7,l4 ,p4 ,wheeler1 #cb1 #he1 #aiaa71 provided a complete vindication of the electromagnetic theory of light4 ,this is all the more significant when the extreme precision obtainable in optical experiments is taken into account4 ,for instance1 ,hastings 7#ce1 #fj1 #ahhh7 has tested ,huygens' construction for double refraction in ,iceland spar and found that 8the difference between a measured index of refraction 444 at an angle of #cj with the crystalline axis1 and the index calculated from ,huygens' law and the measured principal indices of refraction0 is a matter of only #d-e units in the sixth decimal place4 ,since ,maxwell's time the gamut of electromagnetic waves has been steadily extended4 ,the shortest ,hertzian waves merge almost imperceptibly into the longest heat waves of the infra-red1 and from there the known spectrum runs continuously through the visible region to the short waves of the extreme ultra-violet recently disclosed by ,lyman4 ,here there is a short gap until soft ,x-rays are reached1 and finally the domain of radiation comes to an end with gamma rays a billionth of a centimeter in length4 ,maxwell's ether was not a dynamical ether in the sense of ,green's elastic solid medium4 ,in spite of the fact that ,maxwell was always active in devising mechanical analogues to illustrate the phenomena of electromagnetism1 he was never enthusiastic over the speculations of the advocates of a dynamical ether4 ,the electrodynamic equations provided an accurate representation of the electric and magnetic fields1 and beyond that he felt it was needless to go4 ,that ,gibbs 7#bc1 #dge1 #ahhb7 held the same view is made evident by the closing paragraphs of a paper in which he shows that the electromagnetic theory of light accounts in minutest detail for the intricate phenomena accompanying the passage of light through circularly polarizing media4 ,he says3 8,the laws of the propagation of light in plane waves1 which have thus been derived from the single hypothesis that the disturbance by which light is transmitted consists of solenoidal electrical fluxes1 444 are essentially those which are received as embodying the results of experiment4 ,in no particular1 so far as the writer is aware1 do they conflict with the results of experiment1 or require the aid of auxiliary and forced hypotheses to bring them into harmony therewith4 ,in this respect the electromagnetic theory of light stands in marked contrast with that theory in which the properties of an elastic solid are attributed to the ether1--a contrast which was very distinct in ,maxwell's derivation of ,fresnel's laws from electrical principles1 but becomes more striking as we follow the subject farther into its details1 and take account of the want of absolute homogeneity in the medium1 so as to embrace the phenomena of the dispersion of colors and circular and elliptical polarization40 ,further ,dynamical ,theories4--,kelvin1 however1 was not satisfied with this type of ether4 ,to him dynamics was the foundation of all physical phenomena1 and nothing could be said to be explained until a mechanical model was provided4 ,so he returned to the elastic solid theory1 and developed the consequences of the assumption1 already made use of by ,cauchy1 that the ether has a negative volume elasticity of such a value as to make the velocity of the compressional wave zero4 ,in order to prevent such an ether from collapsing it is necessary to assume that it is rigidly attached at its boundaries and that cavities cannot be formed at any point in its interior4 ,now ,gibbs 7#cg1 #abi1 #ahhi7 has pointed out the remarkable fact that the equations describing the motion of ,kelvin's quasi-labile ether are of exactly the same form as the electromagnetic equations4 ,electric displacement is represented by an actual displacement of the ether1 magnetic intensity by a rotation4 ,hence everything which can be explained by the electrodynamic equations finds an analogue in terms of ,kelvin's ether4 ,still another type of dynamic ether which fits the known facts was proposed by ,mc,cullagh and perfected by ,larmor4 ,in this ether a rotational elasticity is premised1 such as would exist if each particle of the medium consisted of three rigidly connected gyrostats with mutually perpendicular axes4 ,in this ether electrical displacements correspond to rotations1 and magnetic strains to etherial displacement4 ,a ,new ,point of ,view4--,while the dynamical school was still dominant in ,england1 another point of view was developing on the continent4 ,kirchhoff denied that it was the province of science to provide mechanical explanations of the ether and electrodynamic phenomena such as ,kelvin conceived to be necessary in order to make these phenomena intelligible4 ,kirchhoff's contention was that the object of science is purely descriptive1--phenomena must be observed1 classified1 and mutual connections described by the fewest number of differential equations possible4 ,mach expressed the same idea somewhat more concisely when he asserted that the aim of science is 8economy of thought40 ,for instance1 in the time of ,newton1 planetary motions could be described quite satisfactorily by means of the three laws of ,kepler4 ,the motion of falling bodies on the earth's surface had been described with a fair degree of accuracy by ,galileo4 ,the value of ,newton's law of gravitation1 however1 lay in the fact that this great generalization made it possible to describe these and many other types of motion by a single simple formula1 instead of leaving each to be governed by a number of separate and apparently unrelated laws4 ,the importance of such a generalization is measured by the economy of thought which it introduces4 ,illustration3 ,,fig4 #a4 ,,fig4 #b4 ,,fig4 #c4 ,electron ,theory4--,the electron theory was leading to a reversal of ,kelvin's idea that dynamical principles must underlie electrodynamics4 ,lorentz had shown that a rigorous solution of the electrodynamic equations did away entirely with ,maxwell's displacement current1 but made the electromagnetic field at a point in space depend not upon the distribution of charges and currents at the same instant1 but at a time earlier sufficient to allow the effect to travel with the velocity of light from the charges and currents producing the field to the point at which the electric and magnetic intensities are to be found4 ,the position of a charge or current element at this earlier time he denoted its 8effective position40 ,the effective distribution1 then1 is that actually seen by an observer stationed at the point under consideration at the instant for which the intensity of the electromagnetic field is to be determined4 ,this solution of the electrodynamic equations led in turn to rigorous expressions for the electric and magnetic intensities produced by a very small charged particle1 such as an electron4 ,fig4 #a shows the electrostatic field produced by a charged particle at rest4 ,the lines of force spread out radially and uniformly in all directions4 ,in fig4 #b the electron is supposed to have a velocity v horizontally to the right of an amount smaller than1 though comparable with1 the velocity of light c4 ,it is seen that the lines of electric force still diverge radially from the charge1 but are crowded in the equatorial plane and spread apart in the polar regions4 ,the dissymmetry grows as the velocity increases until if the velocity of light should be reached the field would be entirely concentrated in a plane at right angles to the direction of motion4 ,now it may be shown that fig4 #b is obtainable from fig4 #a by reducing dimensions in the direction of motion in the ratio of 7#a #b7 3 #a1 where v_/c4 ,for a uniformly convected electric field differs from an electrostatic field only in that the dimensions in the direction of motion are contracted in this particular ratio4 ,fig4 #c represents the electric field of a charged particle which has a uniform acceleration to the right4 ,consider ,faraday's analogy between lines of force and stretched elastic bands4 ,the symmetry of the first two figures shows that in neither of these cases would there be a resultant force on the charged particle4 ,but in the third figure it is obvious that a force to the left is exerted on the charge by its own field4 ,calculation shows this force to be proportional in magnitude to the acceleration4 ,let it be postulated that the resultant force on a charged particle is always zero4 ,then if ,f is the applied force1 the force on the particle due to the reaction of its field will be -- m f1 where f stands for the acceleration and m is a positive constant1 and we have the fundamental equation of dynamics ,f m f #j ,hence1 instead of admitting ,kelvin's contention that all physical phenomena must be given a mechanical explanation1 it would seem more logical to assert that electrodynamics actually underlies mechanics4 ,calculation shows the electromagnetic mass m to vary inversely with the radius of the charged particle4 ,now ,thomson's experiments made it possible to calculate the mass of an electron4 ,hence its radius can be computed1 and is found to be about #b7aj7-ac part of a centimeter1 or one fifty-thousandth part of the radius of the atom4 ,since numbers so small convey little meaning1 consider the following illustration1 due1 in part1 to ,kelvin4 ,imagine a single drop of water to be magnified until it is as large as the earth4 ,the individual atoms would then have the size of baseballs4 ,now magnify one of these atoms until it is comparable in size with ,st4 ,peter's cathedral at ,rome4 ,the electrons within the atom would appear as a few grains of sand scattered about the nave4 ,this separation between the constituent electrons of the atom1--so great in comparison with their dimensions1--explains how alpha particles can be shot by the billion through thin-walled glass tubing without leaving any holes behind or impairing in the slightest degree the high vacuum within the tube4 ,the much smaller high speed beta particles pass through an average of ten thousand atoms without even coming near enough to one of the component electrons to detach it and form an ion4 ,michelson-,morley ,experiment4--,in #ahha ,michelson 7#bb1 #abj1 #ahha7 conceived an ingenious and bold method of measuring the orbital motion of the earth through the luminiferous ether4 ,as the experiment was one involving considerable expense1 ,bell1 the inventor of the telephone receiver1 was appealed to successfully for the funds necessary to carry it through4 ,michelson's experimental plan was as follows3 ,a beam of light traveling in the direction of the earth's motion strikes an unsilvered mirror m at an angle of #de4 ,part of the light passes through1 the rest being reflected at right angles to its original direction4 ,each ray is returned by a mirror at a distance l from m4 ,on meeting again1 the ray whose path has been at right angles to the direction of the earth's motion passes on through the mirror1 while the other ray is reflected so as to bring the two in line and form interference fringes4 ,now consider the effect of the earth's motion on the paths of the two rays4 ,in fig4 #d the earth is supposed to be moving to the right4 ,the unsilvered mirror m bifurcates a beam of light coming from a source a4 ,by the time the ray reflected from m has traveled to the mirror b and back1 m will have moved forward to m'2 a distance #bl1 where the small quantity is the ratio of the earth's velocity to the velocity of light4 ,hence the length of the path traversed by this ray is approximately #bl7#a #b74 ,the other ray will reach the mirror c after the latter has moved forward a distance l_/7#a #b7 and on returning find m at m'4 ,hence its path has a length of roughly #bl7#a #b74 ,the difference in path of the two rays is #bl and consequently they should be a little out of phase on meeting at d4 ,by rotating the apparatus clockwise through #ij the directions of the two rays relative to the earth's motion are interchanged1 and the interference fringes would be expected to shift an amount corresponding to a difference in path of #bbl4 ,this quantity is of course small1--#b is about one one hundred millionth1--but so sensitive are the methods of interferometry that ,michelson felt confident that he would be able to detect the earth's motion through the ether4 ,the apparatus consisted of a table which could be rotated about a vertical axis in much the same way as a spectrometer table1 and provided with arms a meter long to carry the mirrors b and c4 ,with this length of arm the interference fringes from sodium light should shift by an amount corresponding to four hundredths of a wave length when the table is rotated through a right angle4 ,when the experiment was first performed the apparatus was placed on a stone pier in the ,physical ,institute at ,berlin4 ,so sensitive was the instrument to outside vibrations that even after midnight it was found impossible to get consistent readings4 ,finally a satisfactory foundation was constructed in the cellar of the ,astrophysical observatory at ,potsdam4 ,but what was the astonishment of the experimenters to find that the expected shift of the interference fringes did not exist6 ,illustration3 ,,fig4 #d4 ,the extreme delicacy of the experiment made it desirable to confirm the result by repeating it4 ,this was done by ,michelson and ,morley 7#cd1 #ccc1 #ahhg7 in #ahhg4 ,in place of a revolving table a massive slab of stone floating on mercury was used to carry the apparatus4 ,this slab was kept in constant rotation1 the observer following it around4 ,moreover1 the precision of the experiment was greatly increased by reflecting each ray back and forth across the slab a number of times between leaving and returning to the mirror m4 ,the accuracy attained was such as to justify ,michelson in declaring that if the effect sought actually existed it could not be so great as one-twentieth of its calculated value4 ,in #aije ,morley and ,miller#aff repeated the experiment for the second time and succeeded in increasing the sensitiveness of the apparatus to a point such that a motion through the ether of one-tenth of the earth's orbital velocity could have been detected4 ,the displacement looked for in the ,michelson-,morley experiment is known as a second-order effect in that it depends upon the square of the ratio of the velocity of the earth to that of light4 ,michelson at first considered that the negative result obtained confirmed a theory proposed by ,stokes in which it was assumed that the ether inside and near its surface partakes of the motion of the earth1 while that at a distance is practically quiescent4 ,but there are many objections to ,stokes' theory1 one of which was brought out by an experiment of ,michelson's 7#c1 #dge1 #ahig7 in which he attempted by an interference method to detect a difference in the velocity of light at different levels above the earth's surface4 ,the negative result obtained led him to conclude that if ,stokes' theory were true the earth's influence on the ether would have to extend to a distance above its surface comparable with its diameter4 ,meanwhile a more satisfactory explanation was forthcoming4 ,it has been pointed out that a uniformly convected electric field is derivable from an electrostatic field by contracting dimensions in the direction of motion in the ratio 7#a #b7 3 #a4 ,fitzgerald and ,lorentz showed independently that if moving matter is distorted in this same way the result obtained by ,michelson would be just that to be expected4 ,for then the distance of the mirror c from m would be l7#a #b7 instead of l1 and the path of the ray moving parallel to the earth's orbit #bl7#a #b71 which is just that of the other ray4 ,of course when the apparatus is rotated through #ij1 the distance of this mirror from m assumes its normal value again1 and the distance of the other mirror becomes shortened4 ,as all measurement consists in comparing the object to be measured with a standard this contraction could never be detected by experimental methods1 for the measuring rod would contract in exactly the same ratio as the body to be measured4 ,in computing its electromagnetic mass ,abraham had assumed the electron to be a uniformly charged rigid sphere which keeps its spherical form no matter how great a velocity it may be given4 ,he found that the mass increases with the speed at very high velocities1 becoming infinite as the velocity of light is approached1 and that its value depends upon the direction of the applied force4 ,after the ,fitzgerald-,lorentz contraction was seen to be necessary in order to explain ,michelson's result1 ,lorentz calculated the electromagnetic mass of a charged sphere which is deformed into an oblate spheroid when set in motion4 ,for this type of electron too1 the mass approaches infinity for velocities as great as that of light1 and is different for different directions4 ,if a force is applied in the direction of motion the inertia to be overcome is a little greater than when the force is applied at right angles to this direction4 ,thus we have to distinguish between longitudinal and transverse masses4 ,but the masses of ,lorentz's electron are not the same functions of its velocity as those of ,abraham's4 ,kaufmann and after him ,bucherer tested experimentally the relation between transverse mass and velocity by observing the deflections produced by electric and magnetic fields in the paths of high speed beta particles4 ,the latter's work was such an ample confirmation of ,lorentz's formula that it may be considered as proven that a moving electron at least suffers contraction in the direction of motion in the ratio 7#a #b7 3 #a4 ,the electromagnetic theory of light had proved so successful when applied to bodies at rest that ,lorentz was anxious to extend this theory to the optics of moving media4 ,his problem was to find a group of homogeneous linear transformations that would leave the form of the electrodynamic equations unchanged4 ,the ,michelson-,morley experiment had shown that dimensions in the direction of motion must be contracted in the moving system1 those at right angles remaining unaltered4 ,but ,lorentz soon found that it was also necessary to use a new unit of time in the moving system1 and as this time was found to depend upon the position of the point at which it is to be determined1 he called it the local time4 ,lorentz's transformation is just that of the principle of relativity1 but he did not succeed in expressing the electrodynamic equations in terms of the new cordinates and time in exactly the same form as for a system at rest1 for the reason that he failed to endow these new units with sufficient reality to justify him in using them when it came to transforming the velocity term involved in an electric current4 ,principle of ,relativity4--,in #aije appeared in the ,annalen der ,physik#afg a paper destined to alter entirely the point of view from which problems in light and electromagnetic theory are to be approached4 ,the author was ,albert ,einstein1 of ,berne1 ,switzerland1 a young man of twenty-six who had already made a number of notable contributions to theoretical physics4 ,the principle of relativity proposed by ,einstein was by no means new to students of dynamics4 ,newton's first two laws of motion express very clearly the fact that in mechanics all motion is relative4 ,force is proportional to acceleration1 and the relation between the two is the same whether the motion under consideration is referred to fixed axes or to axes moving with a constant velocity4 ,but in connection with the phenomena of light and electromagnetism the case seemed to be quite different4 ,there everything was referred to a fixed ether1 and even though ,lorentz had found a set of transformations which left the electrodymanic equations practically unchanged1 he continued to think in terms of an ether4 ,so physicists were not a little startled when ,einstein postulated that no experiment1 practical or ideal1 could ever distinguish between two systems in such a manner as to warrant the assertion that one of them is at rest and the other in motion4 ,all motion is relative1 and the laws governing physical1 chemical and biological phenomena are the same in terms of the units of one system as in terms of those of any other4 ,einstein next considers some very fundamental questions4 ,what do we mean when we say that two events1 one at ,a and the other at a point ,b far from ,a1 occur at the same time8 ,obviously the expression has no significance unless synchronous clocks are stationed at the two points4 ,but how is it to be determined whether or not these two clocks are synchronous8 ,if instantaneous communication could be established between ,a and ,b the matter would be simple enough4 ,since no infinite velocity of transmission is available1 however1 let a light wave be sent from ,a to ,b and returned to ,a immediately upon its arrival4 ,if the time indicated by the clock at ,b when the signal is received is half way between that at which it left ,a and the time at which it arrives on its return1 then the two clocks may be considered synchronous4 ,now if it desired to measure the length of a bar which is moving parallel to the scale with which the measurement is to be made1 it is necessary to note the positions of the two ends of the bar at the same instant4 ,so even the measurement of the length of a moving body depends upon the condition of synchronism at different points in space4 ,the principle of relativity requires that the velocity of light shall be the same in one system as in another relative to which the first is in motion4 ,hence the definition of synchronism makes it possible to obtain a set of transformations connecting space and time measurement on one system with those on another4 ,this group of transformations is exactly that which ,lorentz had found would transform the electrodynamic equations into themselves4 ,but ,einstein's point of view brought out a remarkable reciprocity which ,lorentz had missed4 ,if two parallel rods ,,mn and ,,op are in motion relative to each other in the direction of their lengths1 not only does ,,op appear shortened to an observer at rest with respect to ,,mn1 but ,,mn appears shorter than normal in the same ratio to an observer who is moving along with the rod ,,op4 ,einstein's theory makes the velocity of light the maximum speed with which a signal can be transmitted4 ,this leads to his celebrated addition theorem4 ,consider three observers ,a1 ,b and ,c4 ,let ,b be moving relative to ,a with a velocity of nine-tenths the velocity of light1 and ,c in the same direction with an equal velocity relative to ,b4 ,in terms of old-fashioned notions of time and space1 the velocity of ,c relative to ,a would be computed as one and eight-tenths the velocity of light4 ,but the relativity theory gives it as ninety-nine hundredths the velocity of light4 ,for the velocity of light can never be surpassed by that of any material object4 ,this deduction from theory is most strikingly confirmed by the fact that although beta particles have been observed with velocities as high as ninety-nine hundredths that of light1 the velocity of light is never quite equalled4 ,it may be remarked in passing that the principle of relativity requires that the masses of all material bodies shall vary with the velocity in the same manner as ,lorentz found to be the case for the electromagnetic mass of the deformable electron4 ,in this connection ,bumstead 7#bf1 #dih1 #aijh7 has devised an elegant method of deducing the ratio of longitudinal to transverse mass4 ,the close connection between electrodynamics and the principle of relativity is obvious from the fact that both lead to the same time and space transformations4 ,furthermore ,l4 ,page 7#cg1 #afi1 #aiad7 has shown that the electrodynamic equations can be derived exactly and in their entirety from nothing more than the kinematics of relativity and the assumption that every element of charge is a center of uniformly diverging lines of force4 ,hence it may safely be asserted that no purely electromagnetic phenomenon can ever come into contradiction with this principle4 ,the simplicity thus introduced into the solution of a certain class of problems is enormous4 ,as an example consider the question as to whether a moving star is retarded by the reaction of its own radiation4 ,this purely electrodynamical problem is of such complexity that attempts to solve it have led to some controversy among mathematical physicists4 ,the principle of relativity tells us without recourse to analysis that no retardation can exist4 ,throughout the nineteenth century the ether has played a fundamental part in all important physical theories of light and electromagnetism4 ,but if it is not possible for experiment to detect even the state of motion of the ether1 why postulate the existence of such a medium8 ,if it does not possess the most fundamental characteristic of matter1 how can it possess such derived properties as density and elasticity1--properties which any conceivable mechanical medium must have in order to transmit transverse vibrations8 ,the relativist does not deny the existence of an ether4 ,to him the question has no more meaning than if he were asked to express an opinion as to the reality of parallels of latitude on the earth's surface4 ,as a convenient medium of expression in describing certain phenomena the ether has justified much of the use which has been made of it4 ,but to attribute to it a degree of substantiality for which there is no warrant in experiment1 is to change it from an aid into an obstacle to the progress of science4 ,from the relativist point of view the distinction is very sharp between those motions of charged particles which are experimentally observable1 and such geometrical conventions as electromagnetic fields1 or analytical symbols as electric and magnetic intensities4 ,these modes of representation have been and still are of the greatest use and importance1 but their value in scientific description must not lead to lack of appreciation of their purely speculative character4 ,finally attention must be drawn to the fact that the discoveries of inductive science1 embodied in the great generalization we have just been discussing1 have led to a more intimate knowledge of the nature of time and space than twenty centuries of introspection on the part of professional philosophers4 ,minskowski1 whose promise of greater achievement was cut off by an untimely death1 has shown that four dimensional geometry makes possible the representation with beautiful simplicity of the time and space relationships of this theory4 ,the one time and three space dimensions merge in such a manner as to form a single whole with not a vestige of differentiation between these fundamental quantities4 ,wilson and ,lewis#afh have made this representation familiar to ,american readers through their admirable translation of ,minskowski's work into the notation of ,gibbs's vector analysis4 ,aberration1 the ,doppler effect1 anomalous dispersion1 --indeed all known phenomena1--are found to be in accord with the principle of relativity4 ,it must be borne in mind1 however1 that this principle applies only to systems moving relative to one another in straight lines with constant velocities4 ,that there is something absolute about rotation has been recognized since ,foucault performed his famous pendulum experiment in #ahea4 ,this experiment 7,c4 ,s4 ,lyman1 #ab1 #bea and #cih1 #ahea7 consisted in setting a pendulum composed of a heavy-brass ball suspended by a long wire into oscillation in such a way as to avoid appreciable ellipticity in its motion4 ,observation of the rate at which the ground rotates relative to the plane of vibration of the pendulum furnished a method of measuring the rotation of the earth about its axis without reference to celestial bodies4 ,the gyroscopic compass in use to-day provides yet another terrestrial method of detecting this rotation4 ,the ,future of ,physics4--,at times during the history of physics it has seemed as if the fundamental laws of this science had been so completely formulated that nothing remained to future generations beyond the routine of deducing to the full the consequences of these laws1 and increasing the precision of the methods used to measure the constants appearing in them4 ,that ,laplace held this view has already been pointed out1 and ,maxwell1 in his introductory lecture at the opening of the ,cavendish laboratory in #ahga1 said1 8,this characteristic of modern experiments--that they consist principally of measurements--is so prominent1 that the opinion seems to have gotten abroad that in a few years all the great physical constants will have been approximately estimated1 and that the only occupation which will then be left to men of science will be to carry on these measurements to another place of decimals40 ,that he himself did not entertain this view is made evident by a succeeding paragraph4 8,but we have no right to think thus of the unsearchable riches of creation1 or of the untried fertility of those fresh minds into which these riches will continue to be poured4 ,it may possibly be true that1 in some of those fields of discovery which lie open to such rough observations as can be made without artificial methods1 the great explorers of former times have appropriated most of what is valuable1 and that the gleanings which remain are sought after rather for their abstruseness than for their intrinsic worth4 ,but the history of science shows that even during that phase of her progress in which she devotes herself to improving the accuracy of the numerical measurement of quantities with which she has long been familiar1 she is preparing the materials for the subjugation of new regions1 which would have remained unknown if she had been contented with the rough methods of her early pioneers44440 ,that ,maxwell's forecast of the prospects of his science was no overestimate will be granted by those who have followed the progress of physics during the last twenty years4 ,yet the work accomplished in the past appears small compared to that which is left to the future4 ,many of the unsolved problems are matters of fitting together puzzling details1 but there is at least one whose solution appears to demand a radical modification in our fundamental physical conceptions4 ,this is the formulation of the laws which govern the motions of electrons and positively charged particles inside the atom4 ,black ,radiation4--,the significance of the problem was first brought to light through the study of black radiation4 ,by a black body is meant one whose distinguishing characteristic is that it emits and absorbs radiation of all frequencies1 and black radiation is that which will exist in thermal equilibrium with such a body4 ,the interest of this type of radiation lies in the fact1 demonstrated by ,kirchhoff1 that its nature depends only upon the temperature of the black body with which it is in equilibrium1 and on none of this body's physical or chemical characteristics4 ,thus we may speak of the 8temperature0 of the radiation itself1 meaning by this the temperature of the material body with which it would be in equilibrium4 ,the problem of black radiation is to find the distribution of energy among the waves of different frequencies at any given temperature4 ,the first step toward a solution was made when ,stefan showed experimentally1 and ,boltzmann as a deduction from thermodynamics and electrodynamics1 that the total energy density summed up over all wave lengths varies with the fourth power of the absolute temperature4 ,if the energy density is plotted as ordinate against the wave length as abscissa1 the experimental curve for any one temperature rises from the axis of abscissas at the origin1 reaches a maximum1 and falls to zero again as the wave length becomes infinitely great4 ,now ,wien's displacement law1 the second important step toward the determination of the form of this curve1 shows that as the temperature is raised the wave length to which its highest point corresponds becomes shorter1--in fact this particular wave length varies inversely with the absolute temperature4 ,this theoretical conclusion is entirely confirmed by experiment4 7,j4 ,w4 ,draper1 #d1 #chh1 #ahdg47 ,farther than this general thermodynamical principles are unable to go4 ,statistical mechanics1 however1 asserts that when a large number of like elements are in thermal equilibrium1 the average kinetic energy associated with each degree of freedom is equal to a universal constant multiplied by the absolute temperature4 ,this 8principle of equi-partition of energy0 has been applied in various ways to obtain a radiation law4 ,the most straightforward method is based on the equilibrium which must ensue between radiation field and material oscillators when the latter emit1 on the average1 as much energy as they absorb4 ,from whatever aspect the problem is treated1 however1 the radiation law obtained from the application of the equi-partition principle is the same4 ,and while this law agrees well with the experimental curve for long wave lengths1 it shows an energy density that becomes indefinitely great for extremely short waves1 which is not only at variance with the facts1 but actually leads to an infinite value of this quantity when integrated over the entire spectrum4 ,the ,energy ,quantum4--,now the principle of equi-partition of energy rests securely on most general dynamical principles4 ,that these dynamical laws are inexact to any such extent as the divergence between theory and experiment would indicate1 is inconceivable2 that they are insufficient when applied to motions of electrons in such intense fields as occur within the atom seems no longer open to doubt4 ,in order to obtain a radiation formula in accord with experiment ,planck has found it necessary to extend the atomic idea to energy1 which he conceives to exist in multiples of a fundamental quantum h1 being the frequency and h ,planck's constant4 ,that some such hypothesis of discontinuity is essential in order to obtain any law that will even approximately fit the experimental facts has been proved by ,poincar4 ,but the precise spot at which the quantum is introduced differs for every new derivation of ,planck's law4 ,as deduced most recently by ,planck himself1 the quantum shows itself in connection with the emission of energy by the material oscillators with which the radiation field is in equilibrium4 ,these oscillators are supposed to act quite normally in every respect except emission2 here the radiation demanded by the electrodynamic equations is cast aside1 and an oscillator is supposed to emit at once all its energy after it has accumulated an amount equal to some integral multiple of h4 ,a form of the theory which does not contain this improbable contradiction of the firmly established facts of electrodynamics introduces the quantum into the specification of the energy of vibration which is permitted to each oscillator4 ,here both emission and absorption follow the classical theory1 but the motion of an emitting and absorbing linear oscillator of frequency is supposed to be stable only for those amplitudes for which the energy of its oscillations is an integral multiple of h4 ,in order to maintain the energy at these particular values1 the oscillator may draw energy from1 or deposit surplus energy with1 other degrees of freedom which partake neither in emission nor absorption1 but act merely as storehouses4 ,photoelectric ,effect4--,when investigating the production of electromagnetic waves1 ,hertz had noticed that a spark passed more readily between the terminals of his oscillator when the negative electrode was illuminated by light from another spark4 ,further investigation by ,hallwachs1 ,elster and ,geitel1 and others showed that this effect was due to the emission of electrons by a metal exposed to the influence of ultra-violet light4 ,lenard discovered that the energy with which a negatively charged particle is ejected is entirely independent of the intensity of the light1 and further investigation showed it to depend only on the frequency4 ,einstein suggested that the electrons appearing in this so-called photo-electric effect start from within the metal with an initial energy h4 ,in passing through the surface a resistance is encountered1 however1 so he concluded that the energy with which the fastest moving electrons appear outside the metal should be equal to h less the work done in overcoming this resistance4 ,recent experiments not only confirm this relation1 but provide a most satisfactory method of determining the value of h4 ,millikan#afi finds it to be #feg7aj7-bg ergs sec41 which gives the quantum for yellow light a value sixty times as great as the heat energy of a monatomic gas molecule at ,o,c4 ,that this large amount of energy can be transferred from the incident light to the ejected electron is quite out of the question2 it must come from within the atom4 ,in this way some indication is obtained of how vast intra-atomic energies must be4 ,structure of the ,atom4--,the generally accepted model of the atom is that due chiefly to ,rutherford4#agj ,he considers it to be constituted of electrons revolving about a positive nucleus either singly or grouped in concentric rings1 in much the same manner as the planets revolve around the sun4 ,experiments on the scattering of alpha rays1 however1 show that the nucleus1 while it must have a positive charge sufficient to neutralize the charges of all the electrons moving around it1 cannot have a volume of an order of magnitude greater than that of the electron4 ,the number of unit charges residing on it1 except in the case of hydrogen1 which is supposed to consist of a singly charged nucleus and only one electron1 is found to be approximately half the atomic weight4 ,thus helium1 with an atomic weight of about four1 has a doubly charged nucleus with two electrons revolving about it1 and lithium a triply charged nucleus and three electrons4 ,the number of unit charges on the nucleus is supposed to correspond with the atomic number used by ,moseley in interpreting the results of his experiment on the ,x-ray spectra of the elements4 ,now the electron which is revolving around the positive nucleus of a hydrogen atom1 must1 according to electrodynamic laws1 radiate energy4 ,this radiation will act as a resistance to its motion1 causing its orbit to become smaller and its frequency to increase4 ,hence luminous hydrogen would be expected to give off a continuous spectrum4 ,the very fine lines actually found seem inexplicable on the classical dynamical and electrodynamical theories4 ,these lines1 and those of many other spectra1 may even be grouped into series1 and the relations between them expressed in mathematical form4 ,formul have been proposed by ,balmer1 ,rydberg1 ,ritz and others1 all of which contain a universal constant ,n as well as certain parameters which must be varied by unity in passing from one line of a series to the next4 ,in #aiac ,bohr#aga proposed anatomic theory which brings to light a remarkable numerical relationship between this quantity ,n and ,planck's constant h4 ,he postulated that the electron in the hydrogen atom1 for instance1 cannot revolve in a circle of any arbitrary radius1 but is confined to those orbits for which its kinetic energy is an integral multiple of hn1 n being its orbital frequency4 ,now at times this electron is supposed to jump from an outer to an inner orbit1 when the excess energy of the first orbit over the second is radiated away4 ,but the energy emitted is also taken to be equal to h1 where is the frequency of the radiation4 ,hence can be determined1 and the expression obtained for it is exactly that given long before by ,balmer as an empirical law4 ,the most remarkable thing about it1 however1 is that ,bohr's result contains a constant involving h and the electronic charge and mass which has precisely the value of the universal constant ,n of ,balmer's and ,rydberg's formul4 ,in all1 the theory accounts for three series of hydrogen1 and yields satisfactory results for helium atoms which have lost an electron1 or lithium atoms which have a double positive charge4 ,but for atoms which retain more than a single electron it seems no longer to hold4 ,the three mentioned are only the most clearly defined of a growing group of phenomena in which the quantum manifests itself4 ,its significance and the alteration in our fundamental conceptions to which it seems to be leading is for the future to make clear4 ,that it presents the most important and interesting problem as yet unsolved few physicists would deny4 ,american ,physicists4--,in attempting to cover the progress of physics during the last hundred years in the space of a few pages1 many important developments of the subject have of necessity remained untouched1 and the treatment of many others has been entirely inadequate4 ,among those appearing in the ,journal of which no mention has been made are ,le,conte's 7#be1 #fb1 #aheh7 discovery of the sensitive flame and ,rood's 7#df1 #agc1 #ahic7 invention of the flicker photometer4 ,however1 enough has been recounted to indicate the preeminent position in the history of physics in ,america occupied by four men3 ,joseph ,henry1 of the ,albany ,academy1 ,princeton1 and the ,smithsonian ,institution2 ,henry ,augustus ,rowland1 of ,johns ,hopkins ,university2 ,josiah ,willard ,gibbs1 of ,yale2 and ,albert ,abraham ,michelson1 of the ,united ,states ,naval ,academy1 ,case ,school of ,applied ,science1 ,clark ,university1 and the ,university of ,chicago4 ,of these1 the last named has the distinction of being the only ,american physicist to have received the ,nobel prize1 though there is little doubt that the other three would have been similarly honored had not their important work been published prior to the institution of this award4 ,all four occupy high places in the ranks of the world's great men of science1 and the investigations carried out by them and their fellow workers in ,america have given to their country a position in the annals of physics which is by no means insignificant4 ,the ,journal's ,part in ,meteorology4 ,the meteorological investigations published in the early numbers of the ,journal have played an important role in establishing a correct theory of storms4 ,before the origin of the ,united ,states ,signal ,service in #ahga no systematic weather reports were issued by any governmental agency in this country1 and consequently the work of collecting as well as interpreting meteorological data rested entirely in the hands of interested individuals and institutions4 ,the earliest important studies of storms to appear in the ,journal were contributed by ,redfield of ,new ,york1 whose first paper 7#bj1 #ag1 #ahca7 treated in considerable detail a violent storm which passed over ,long ,island1 ,connecticut and ,massachusetts in #ahba4 ,he concluded that 8the direction of the wind at a particular place1 forms no part of the essential character of a storm1 but is only incidental to that particular portion 444 of the track of the storm which may chance to become the point of observation1 444 the direction of the wind being1 in all cases1 compounded of both the rotative and progressive velocities of the storm40 ,a few years later1 analyses of twelve 8gales and hurricanes of the ,western ,atlantic0 7#ca1 #aae1 #ahcg7 led to the statement that the phenomena involved 8are to be ascribed mainly to the mechanical gravitation of the atmosphere1 as connected with the rotative and orbital movements of the earth's surface40 ,in this paper is emphasized the fact that the wind may blow in diametrically opposite directions at points near the storm center4 8,while one vessel has been lying-to in a heavy gale of wind1 another1 not more than thirty leagues distant1 has at the very same time been in another gale equally heavy1 and lying-to with the wind in quite an opposite direction40 ,from an accompanying sketch showing wind directions1 the reader would infer that1 at this time1 ,redfield believed the motion of the air to be very nearly in circles about the storm center4 ,the same idea is conveyed by a later paper 7#db1 #aab1 #ahdb74 ,espy 7#ci1 #abj1 #ahdj7 of ,philadelphia1 however1 claimed that observation showed rather that the wind blew inwards toward a central point1 if the storm were round in shape1 or toward a central line1 if it were oblong4 ,this view ,redfield 7#db1 #aab1 #ahdb7 contested1 and brought forth much evidence to prove its falsity4 ,a later statement 7#a1 #a1 #ahdf7 of his own theory is as follows3 8,i have never been able to conceive1 that the wind in violent storms moves only in circles4 ,on the contrary1 a vortical movement 444 appears to be an essential element of their violent and long-continued action1 of their increased energy towards the center or axis1 and of the accompanying rain4444 ,the degree of vorticular inclination in violent storms must be subject1 locally1 to great variations2 but it is not probable that1 on an average of the different sides1 it ever comes near to forty-five degrees from the tangent of a circle1--and that such average inclination ever exceeds two points of the compass1 may well be doubted40 ,a qualitative explanation of the effect of the earth's rotation on the direction of the wind near the storm center had already been given by ,tracy 7#de1 #fe1 #ahdc71 and this was followed some years later by ,ferrel's 7#ca1 #bg1 #ahfa7 very thorough quantitative investigation of the dynamics of the atmosphere4 ,a number of individuals kept systematic records of meteorological observations1 among whom was ,loomis1 whose storm analyses did much to settle the merits of the rival theories of ,redfield and ,espy4 ,in studying the storm of #ahcf 7#dj1 #cd1 #ahda7 he had drawn on the map lines through those points in the track of the storm where the barometer1 at any given hour1 is lowest4 ,while this method revealed the general direction in which the storm was progressing1 it failed to give much indication of its size or shape4 ,in discussing the two tornadoes of ,february1 #ahdb1 one of which had already been described in the ,journal 7#dc1 #bgh1 #ahdb71 he adopted a new and more illuminating graphical method4 ,instead of connecting points of lowest pressure1 he drew a curve through all points where the barometer stood at its normal level1 then one through those points at which the pressure was of an inch below normal1 and so on4 ,temperature he treated in much the same way1 and the strength and direction of the wind were indicated by arrows4 ,this innovation gave to his storm analyses a significance which had been entirely lacking in those of his predecessors1 and led to the familiar systems of isobars and isotherms in use on the daily charts issued by the ,weather ,bureau at the present time4 ,loomis advocated careful observations for one year at stations #ej miles apart all over the ,united ,states1 so that sufficient data might be obtained to settle once for all the law of storms4 ,his efforts1 seconded by those of ,henry1 ,bache1 ,pierce1 ,abbe1 and ,lapham1 led eventually to the establishment of the ,signal ,service1 and the publication of daily weather maps according to the plan advocated thirty years before4 ,these maps afforded a basis for further analyses of storms1 which he published in numerous 8,contributions to ,meteorology0 7#h1 #a1 #ahgd1 et seq47 between #ahgd and his death in #ahij4 ,in addition to his work on storms1 ,loomis made a careful study of the earth's magnetism 7#cd1 #bij1 #ahch et seq471 and of the aurora borealis 7#bh1 #che1 #ahei et seq474 ,that a connection existed between sunspots1 aurora1 and terrestrial magnetism was already recognized4 ,loomis 7#ej1 #aec1 #ahgj et seq471 however1 showed that the periodicity of the aurora borealis1 as well as of excessive disturbances in the earth's magnetic field1 corresponds very closely with that of sunspots4 ,notes4 ,footnote #aed3 ,j4 ,w4 ,gibbs1 ,trans4 ,conn4 ,acad4 ,arts and ,sci41 #c1 #ajh and #cdc4 ,abstract by the author1 the ,journal1 #af1 #dda1 #ahgh4 ,footnote #aee3 ,h4 ,k4 ,onnes1 ,nature1 #ic1 #dha1 #aiad4 ,footnote #aef3 ,h4 ,hertz1 ,wied4 ,ann41 #cd1 #eea1 #ahhh et seq4 ,footnote #aeg3 ,e4 ,f4 ,nichols and ,g4 ,f4 ,hull1 ,phys4 ,rev41 #ac1 #cjg1 #aija et seq4 ,footnote #aeh3 ,j4 ,j4 ,thomson1 ,phil4 ,mag41 #dd1 #bic1 #ahig4 ,footnote #aei3 ,r4 ,a4 ,millikan1 ,phys4 ,rev41 #b1 #aji1 #aiac4 ,footnote #afj3 ,p4 ,zeeman1 ,phil4 ,mag41 #dc1 #bbf1 #ahig4 ,footnote #afa3 ,h4 ,a4 ,lorentz1 ,phil4 ,mag41 #dc1 #bcb1 #ahig4 ,footnote #afb3 ,s4 ,j4 ,barnett1 ,phys4 ,rev41 #f1 #bci1 #aiae1 and #aj1 #g1 #aiag4 ,footnote #afc3 ,w4 ,c4 ,rntgen1 ,wied4 ,ann41 #fd1 #a1 #ahih et seq4 ,footnote #afd3 ,w4 ,friedrich1 ,p4 ,knipping1 and ,m4 ,laue1 ,ann4 d4 ,phys41 #da1 #iga1 #aiac4 ,footnote #afe3 ,h4 ,g4 ,j4 ,moseley1 ,phil4 ,mag41 #bf1 #ajbd1 #aiac1 and #bg1 #gjc1 #aiad4 ,footnote #aff3 ,e4 ,w4 ,morley and ,d4 ,c4 ,miller1 ,phil4 ,mag41 #i1 #fhj1 #aije4 ,footnote #afg3 #ag1 #hia1 #aije4 ,footnote #afh3 ,e4 ,b4 ,wilson and ,g4 ,n4 ,lewis1 ,proc4 ,am4 ,acad41 of ,arts and ,sci41 #dh1 #chi1 #aiab4 ,footnote #afi3 ,r4 ,a4 ,millikan1 ,phys4 ,rev41 #g1 #cee1 #aiaf4 ,footnote #agj3 ,e4 ,rutherford1 ,phil4 ,mag41 #ba1 #ffi1 #aiaa4 ,footnote #aga3 ,n4 ,bohr1 ,phil4 ,mag41 #bf1 #a1 #aiac et seq4 ,,xii ,a ,,century ,,of ,,zoology ,,in ,,america ,by ,,wesley ,k4 ,,coe ,this article is intended as a brief survey of the development of zoology in ,america1 and no attempt is made to give a general history of the science4 ,there are numerous accounts in several languages of zoological history in general1 among them being ,w4 ,a4 ,locy's 8,biology and its ,makers40 ,brief outlines of the history of zoology may be found in many zoological and biological text-books4 ,for the history of ,american zoology the reader is referred to ,packard's report on 8,a ,century's ,progress in ,american ,zoology10 published in the ,american ,naturalist1 7#aj1 #eia1 #ahgf71 to ,packard's 8,history of ,zoology10 published in volume #a of the ,standard ,natural ,history 7pp4 lxii to lxxii1 #ahhe72 to ,g4 ,b4 ,goode's 8,beginnings of ,natural ,history in ,america10#agb and 8,beginnings of ,american ,science10#agc and to ,h4 ,s4 ,pratt's ,manual of the ,common ,invertebrate ,animals 7pp4 #a-i71 #aiaf4 ,in ,binney's 8,terrestrial ,air-breathing ,mollusks of the ,united ,states0 7#ahea7 is a chapter on the rise of scientific zoology in the ,united ,states which well describes the zoological conditions in the early part of the century1 while numerous monographs and papers give the history of the investigations on the various groups of animals or on special fields of study4 ,brief biographical sketches of the most distinguished of our older ,naturalists--,wilson1 ,audubon1 ,agassiz1 ,wyman1 ,gray1 ,dana1 ,baird1 ,marsh1 ,cope1 ,goode and ,brooks are given in 8,leading ,american ,men of ,science10 edited by ,david ,starr ,jordan1 #aiaj4 ,more extensive biographies have been published separately1 and the activities of a number of the more prominent ,american zoologists have been recorded in the ,biographical ,memoirs of the ,national ,academy of ,sciences4 ,the developmental history of zoology in ,america falls naturally into four fairly well marked periods1 namely3--#a1 ,period of descriptive natural history1 previous to #ahdg1 embracing the early studies on the classification and habits of animals1 characteristic of the zoological work previous to the arrival of ,louis ,agassiz in ,america4 #b1 ,period of morphology and embryology1 #ahdg-ahgj1 during which the influence of ,agassiz directed the zoological studies toward problems concerning the relationships of animals as indicated by their structure and developmental history4 #c1 ,period of evolution1 #ahgj-ahij1 when the principle of natural selection received general recognition and the zoological studies were largely devoted to the applications of the theory to all groups of animals4 #d1 ,period of experimental biology1 since #ahij1 during which time have occurred the remarkable advances in our knowledge of the nature of organisms through the application of experimental methods in the various branches of the modern science of biology4 ,american ,zoology in #ahah4 ,at the beginning of the century which this volume commemorates1 the accumulated biological knowledge of the world consisted mainly of what is to-day called descriptive natural history4 ,the zoological treatises of the time were devoted to the names1 distinguishing characters and habits of the species of animals and plants known to the naturalists of ,europe either as native species or as the results of explorations in other parts of the world4 ,this required little more than a superficial knowledge of their general anatomical structures4 ,the naturalists of those days had no conception of the life within the cell which we now know to form the basis of all the activities of animals and plants1 nor had they even the necessary means of studying such life4 ,the compound microscope1 so necessary for the study of even the largest of the cells of the body1 was not adapted to such use until #ahce1 although the instrument was invented in the seventeenth century4 ,with the perfection of the microscope came a period of enthusiastic study of microscopic organisms and microscopic structures of higher animals and plants4 ,it was not until twenty years after the founding of the ,journal that the cell theory of structure and function in all organisms was established by the discoveries of ,schleiden and ,schwann4 ,the beginning of the nineteenth century saw great zoological activity in ,europe1 and particularly in ,france4 ,buffon's great work on the ,natural ,history of ,animals had recently been completed1 ,cuvier had only one year before published his classic work in comparative anatomy1 8,le ,regne ,animal10 and ,lamarck's 8,philosophie ,zoologique0 had then aroused a new interest in classification and comparative anatomy from an evolutionary standpoint4 ,e4 ,geoffroy ,st4-,hilaire was at the same time supporting an evolutionary theory based on embryonic influences resulting in sudden modifications of adult structure4 ,these epoch-making discoveries and theories gained a considerable following in ,france1 ,germany and ,england1 but seem to have had little influence on the zoological work of the following half century in ,america4 ,the science of zoology as understood to-day is commonly said to have been founded by ,linnus by the publication of the modern system of classification in the tenth edition of his 8,systema ,natur0 in #ageh4 ,the influence of ,linnus aroused an interest in biological studies throughout ,europe and stimulated new investigations in all groups of organisms4 ,such studies as related to animals naturally followed first the classification and relationship of species1 that is1 systematic zoology1 and then led gradually into the development of the different branches of the subject1 as morphology1 comparative anatomy1 physiology1 and embryology1 which eventually were recognized as almost independent sciences4 ,of these sciences systematic zoology1 which has come to mean the classification1 structure1 relationship1 distribution and habits1 or natural history1 is the pioneer in any region4 ,thus we find in our new country at the time of the founding of the ,journal in #ahah1 only sixty years after the publication of ,linnus' great work1 the beginning of ,american zoology taking the form of the collection and description of our native animals4 ,it is true that many of our more conspicuous and easily collected animals were described long before the opening of the nineteenth century1 but this is to be credited mainly to the work of ,european naturalists who had made expeditions to this country for the purpose of studying and collecting4 ,these collections were then taken to ,europe and the results published there4 ,we thus find in the #abth edition of ,linnus descriptions of over #ejj ,american species1 about half of which were birds4 ,as an illustration of the extent to which some of these works covered the field even in those early days may be mentioned a monograph in two quarto volumes with many beautifully colored plates on the 8,natural ,history of the rarer ,lepidopterous ,insects of ,georgia40 ,this was published in ,london in #agig by ,j4 ,e4 ,smith from the notes and drawings of ,john ,abbot1 one of the keenest naturalists of any period4 ,during the early years of the nineteenth century1 however1 economic conditions in our country became such as to give opportunity for scientific thought4 ,educated men then formed themselves into societies for the discussion of scientific matters4 ,this naturally led to the establishment of publications whereby the papers presented to the societies could be published and made available to the advancement of science generally4 ,the most influential of these was the ,journal of the ,philadelphia ,academy of ,natural ,science1 which was established in #ahag1 and was devoted largely to zoological papers4 ,the ,annals of the ,new ,york ,lyceum of ,natural ,history date from #ahbc1 and the ,journal of the ,boston ,society of ,natural ,history from #ahcd4 ,the ,transactions of the ,american ,philosophical ,society in ,philadelphia and the ,memoirs of the ,american ,academy of ,arts and ,sciences in ,boston also published many zoological articles4 ,in these publications and in the ,journal1 which was founded in #ahah1 appear the descriptions of newly discovered animal species1 with observations on their habits4 ,the number of investigators in this field in the first quarter of the nineteenth century was but few1 and most of these were compelled to take for the work such time as they could spare from their various occupations4 ,gradually the workers became more numerous until about the middle of the century zoology was taught in all the larger colleges4 ,the science thereby developed into a profession4 ,for some years the studies remained largely of a systematic nature1 and embraced all groups of animals1 but long before the close of the century the attention of the majority of the ever increasing group of zoologists was directed into more promising channels for research and there came the development of the sciences of comparative anatomy1 physiology1 embryology1 experimental zoology1 cytology1 genetics1 and the like1 while the systematists became specialists in the various animal groups4 ,but the work in systematic zoology remains incomplete and many native species are still undescribed or imperfectly classified4 ,it is perhaps fortunate that a few faithful systematists remain at their tasks and tend to keep the experimentalists from the disaster which might otherwise result from the confusion of the species under investigation4 ,period of ,descriptive ,natural ,history4--,previous to #ahdg4 ,of the few ,american naturalists whose writings were published toward the end of the eighteenth century and at the beginning of the nineteenth the names of ,william ,bartram 7#agci-ahbc71 ,benjamin ,barton 7#agff-ahae71 ,samuel ,mitchill 7#agfd-ahca71 ,william ,peck 7#agfc-ahbb71 and ,thomas ,jefferson 7#agdc-ahbf71 require special mention4 ,bartram's entertaining volume describing his travels through the ,carolinas1 ,georgia and ,florida1 published in #agic1 contains a most interesting account of the birds and other animals which he found4 ,barton wrote many charming essays on the natural history of animals1 but was more particularly interested in botany4 ,mitchill's most important works include a history of the fishes of ,new ,york 7#ahad71 and additions to an edition of ,bewick's ,general ,history of ,quadrupeds4 ,the latter1 published in #ahjd1 contains descriptions and figures of some ,american species and is the first ,american work on mammals4 ,peck has the distinction of writing the first paper on systematic zoology published in ,america4 ,this was a description of new species of fishes and was printed in #agid4 ,he is also well known for his work on insects and fungi4 ,jefferson in #agha published an interesting book describing the natural history of ,virginia1 and during his presidency was of inestimable service to zoology through his support of scientific expeditions to the western portions of the country4 ,previous to ,agassiz's introduction of laboratory methods of study in comparative anatomy and embryology in #ahdg1 ,american naturalists generally confined their attention to the study of the classification and habits of the multitude of undescribed animals and plants of the region4 ,such studies were naturally begun on the larger and more generally interesting animals such as the birds and mammals1 and although many of these were fairly well described as to species before the opening of the nineteenth century1 little was known of their habits4 ,the natural history of our eastern birds first became well known through the accurate illustrations and exquisitely written descriptions of ,alexander ,wilson 7in #ahjh-ahac74 ,bonaparte's continuation of ,wilson's work was published in four folio volumes beginning in #ahbf4 ,in #ahbh appeared the first of ,audubon's magnificent folio illustrations of our birds4 ,these were published in ,england1 with later editions of smaller plates in ,america4 ,nuttall's ,manual of the ,ornithology of the ,united ,states appeared in #ahcb-ahcd4 ,the second work on ,american mammals appeared in the second ,american edition of ,guthrie's ,geography1 published in #ahae4 ,the author is supposed to have been ,george ,ord1 although his name does not appear4 ,in #ahbe ,harlan published his 8,fauna ,americana3 ,descriptions of the ,mammiferous ,animals inhabiting ,north ,america40 ,this was largely a compilation from ,european writers1 particularly from ,demarest's ,mammalogie1 and had little value4 ,in #ahbf ,amos ,eaton published a small 8,zoological ,text-book comprising ,cuvier's four grand divisions of ,animals3 also ,shaw's improved ,linnean genera1 arranged according to the classes and orders of ,cuvier and ,latreille4 ,short descriptions of some of the most common species are given for students' exercises4 ,prepared for ,rensselaer school and the popular class room40 8,four hundred and sixty-one genera are described in this text-book4 ,they embrace every known species of the ,animal ,kingdom40 ,this is a compilation from ,european sources with a few ,american species of various groups included4 ,on the other hand1 ,godman's ,natural ,history1 in three volumes 7#ahbf-ahbh71 was an illustrated and creditable work4 ,such was also the case with ,sir ,john ,richardson's ,fauna ,boreali ,americana of which the volume on quadrupeds was published in ,england in #ahbi4 ,the other volumes on birds1 fishes and insects appeared between #ahbg and #ahcf4 ,audubon and ,bachman's beautifully illustrated 8,quadrupeds of ,north ,america0 was issued between #ahda and #ahej4 ,about #ahdj several of the states inaugurated natural history surveys and published catalogues of the local faunas4 ,the reports on the animals of ,massachusetts and ,new ,york are the most complete zoological monographs published in ,america up to that time4 ,this is particularly true of ,de,kay's ,natural ,history of ,new ,york published between #ahdb and #ahdd in beautifully illustrated quarto volumes4 ,the leader in the systematic studies in the early part of the century was ,thomas ,say1 who published descriptions of a large number of new species of animals1 particularly reptiles1 mollusks1 crustacea and insects4 ,say's conchology1 printed in #ahaf in ,nicholson's ,cyclopedia1 is the first ,american work of its kind4 ,this was reprinted in #ahai under the title 8,land and ,fresh-water ,shells of the ,united ,states40 ,in #ahbd-ahbh appeared the three volumes of ,say's ,american ,entomology4 ,the prominent position held by ,say in the zoological work of this period is illustrated by the following paragraph from ,eaton's ,zoological ,text-book 7#ahbf1 p4 #acc73 8,at present but a small proportion of ,american ,animals1 excepting those of large size1 have been sought out 444 ,and though ,mr4 ,say is doing much2 without assistance1 his life must be protracted to a very advanced period to afford him time to complete the work4 ,but if every student will contribute his mite1 by sending ,mr4 ,say duplicates of all undescribed species1 we shall probably be in possession of a system1 very nearly complete1 in a few years40 ,how different is the attitude of the zoologist of to-day who sees the goal much further away after a century's progress through the industry of hundreds of investigators4 ,during the period of ,say's most active work he is reported to have 8slept in the hall of the ,philadelphia ,academy of ,natural ,sciences1 where he made his bed beneath the skeleton of a horse and fed himself on bread and milk40 ,next to ,say1 the most active zoologist of the early part of the century was ,charles ,alexander ,lesueur1 who described and beautifully illustrated many new species of fishes1 reptiles1 and marine invertebrates4 ,a memoir by ,george ,ord1 published in this ,journal 7#h1 #ahi1 #ahdi71 gives a full list of ,lesueur's papers4 ,one of the most prolific writers of the period was ,constantine ,rafinesque1 a man of great brilliancy but one whose imagination so often dominated his observations that many of his descriptions of plants and animals are wholly unreliable4 ,united ,states ,exploring ,expedition4--,in #ahch a fortunate circumstance occurred which eventually brought ,american systematic zoology into the front ranks of the science4 ,this opportunity was offered by the ,united ,states ,exploring ,expedition under the command of ,admiral ,wilkes4 ,with ,james ,d4 ,dana as naturalist1 the expedition visited ,madeira1 ,cape ,verde ,islands1 eastern and western coasts of ,south ,america1 ,polynesia1 ,samoa1 ,australia1 ,new ,zealand1 ,fiji1 ,hawaiian ,islands1 west coast of ,united ,states1 ,philippines1 ,singapore1 ,cape of ,good ,hope1 etc4 ,of the extensive collections made on this four-years' cruise1 ,dana had devoted particular attention to the study of the corals and allied animals 7,zoophytes7 and to the crustacea4 ,in #ahdf the report on the ,zoophytes was published in elegant folio form with colored plates4 ,six years later the first volume of the report on ,crustacea appeared1 with a second volume after two additional years 7#ahed74 ,these reports describe and beautifully illustrate hundreds of new species1 and include the first comprehensive studies of the animals forming well-known corals4 ,they remain as the most conspicuous monuments in ,american invertebrate zoology4 ,unfortunately the very limited edition makes them accessible in only a few large libraries4 ,the other1 equally magnificent1 volumes include3 ,mollusca and ,shells1 by ,a4 ,a4 ,gould1 #ahef2 ,herpetology1 by ,charles ,girard1 #aheh2 ,mammalogy and ,ornithology1 by ,john ,cassin1 #aheh4 ,principal investigators4--,of the many writers on animals at this period of descriptive natural history1 the following were prominent in their special fields of study3 ,ayres1 ,lesueur1 ,mitchill1 ,storer1 ,linsley1 ,wyman1 ,de,kay1 ,smith1 ,kirtland1 ,rafinesque and ,haldeman described the fishes4 ,green1 ,barton1 ,harlan1 ,le ,conte1 ,say1 and especially ,holbrook1 studied the reptiles and amphibia4 ,holbrook's great monograph of the reptiles 7,north ,american ,herpetology7 was published between #ahcd and #ahde4 ,wilson1 ,audubon1 ,nuttall1 ,cooper1 ,de,kay1 ,brewer1 ,ord1 ,baird1 ,gould1 ,bachman1 ,linsley and ,fox were among the numerous writers on birds4 ,godman1 ,ord1 ,richardson1 ,audubon1 ,bachman1 ,de,kay1 ,linsley and ,harlan published accounts of mammals4 ,on the invertebrates an important general work entitled 8,invertebrata of ,massachusetts2 ,mollusca1 ,crustacea1 ,annelida and ,radiata0 was published by ,a4 ,a4 ,gould in #ahda1 which contains all the ,new ,england species of these groups known to that date4 ,lea1 ,totten1 ,adams1 ,barnes1 ,gould1 ,binney1 ,conrad1 ,hildreth1 ,haldeman1 were the principal writers on mollusks4 ,the crustacea were studied by ,say1 ,gould1 ,haldeman1 ,dana2 the insects by ,say1 ,melsheimer1 ,peck1 ,harris1 ,kirby1 ,herrick2 the spiders by ,hentz2 the worms by ,lee2 the coelenterates and echinoderms by ,say1 ,mantell and others4 ,the history of entomology in the ,united ,states previous to #ahdf is given by ,john ,g4 ,morris in the ,journal 7#a1 #ag1 #ahdf74 ,in this article ,f4 ,v4 ,melsheimer is stated to be the father of ,american ,entomology1 while ,say was the most prolific writer4 ,say's entomological papers1 edited by ,j4 ,l4 ,le ,conte1 were completely reprinted with their colored illustrations in #ahei4 ,the first economic treatise is that by ,harris on ,insects ,injurious to ,vegetation2 printed in #ahda4 ,this has had many editions4 ,zoology in the ,american ,journal of ,science1 #ahah-ahdf4 ,the establishment of the ,journal gave a further impetus to the scientific activities of ,americans in furnishing a convenient means for publishing the results of their work4 ,in the first volume of the ,journal1 for example1 are two zoological articles by ,say and a dozen short articles on various topics by ,rafinesque1 the latter being curious combinations of facts and fancy4 ,most of the zoological papers appearing in its first series of #ej volumes are characteristic of an undeveloped science in an undeveloped country4 ,they deal1 naturally1 with observational studies on the structure and classification of species discovered in a virgin field1 with notes on habits and life histories4 ,many of the papers are purely systematic and include the first descriptions of numerous species of our mollusks1 crustacea1 insects1 vertebrates and other groups4 ,of these1 the writings of ,c4 ,b4 ,adams1 ,barnes1 ,a4 ,a4 ,gould and ,totten on mollusks1 of ,j4 ,d4 ,dana on corals and crustacea1 of ,harris on insects1 of ,harlan on reptiles1 and of ,jeffries ,wyman and ,d4 ,humphreys ,storer on fishes are representative and important4 ,the progress of zoology in ,america during the first twenty-eight years of the ,journal's existence1 that is1 up to the year #ahdf1 is thus summarized by ,professor ,silliman in the preface to vol4 #ej 7page ix71 #ahdg3 8,our zoology has been more fully investigated than our mineralogy and botany2 but neither department is in danger of being exhausted4 ,the interesting travels of ,lewis and ,clark have recently brought to our knowledge several plants and animals before unknown4 ,foreign naturalists are frequently visiting our territory2 and1 for the most part1 convey to ,europe the fruits of their researches1 while but a small part of our own is examined and described by ,americans3 certainly this is little to our credit and still less to our advantage4 ,honorable exceptions to the truth of this remark are furnished by the exertions of some gentlemen in our principal cities1 and in various other parts of the ,union40 ,during these #bh years the ,journal had been of great service to zoology not only in the publication of the results of investigations but also in the review of important zoological publications in ,europe as well as in ,america4 ,there were also the reports of meetings of scientific societies4 ,in fact all matters of zoological interest were brought to the attention of the ,journal's readers4 ,the ,influence of ,louis ,agassiz4 ,at the time of the founding of the ,journal and for nearly thirty years thereafter descriptive natural history constituted practically the entire work of ,american zoologists4 ,in this respect ,american science was far behind that in ,europe and particularly in ,france4 ,it was not until the fortunate circumstances which brought the ,swiss naturalist1 ,louis ,agassiz1 to our country in #ahdf that the modern conceptions of biological science were established in ,america4 ,agassiz was then #ci years of age and had already absorbed the spirit of generalization in comparative anatomy which dominated the work of the great leaders in ,europe1 and particularly in ,paris4 ,the influence of ,leuckart1 ,tiedemann1 ,braun1 ,cuvier and ,von ,humboldt directed ,agassiz's great ability to similar investigations1 and he was rapidly coming into prominence in the study of modern and fossil fishes when the opportunity to continue his research in ,america was presented4 ,on arriving on our shores the young zoologist was so inspired with the opportunities for his studies in the new country that he decided to remain4 ,bringing with him the broad conceptions of his distinguished ,european masters1 he naturally founded a similar school of zoology in ,america4 ,it is from this beginning that the present science of zoology with its many branches has developed4 ,it must be remembered in this connection that the great service which ,agassiz rendered to ,american zoology consisted mainly in making available to students in ,america the ideals and methods of ,european zoologists4 ,this he was eminently fitted to do both because of his ,european training and because of his natural ability as an inspiring leader4 ,the times in ,america1 moreover1 were fully ripe for the advent of ,european culture4 ,there were already in existence natural history societies in many of our cities and college communities4 ,these societies not only held meetings for the discussion of biological topics1 but established museums open to the public1 and to which the public was invited to contribute both funds and specimens4 ,this led to a wide popular interest in natural history4 ,it was therefore comparatively easy for such a man as ,agassiz to develop this favorable public attitude into genuine enthusiasm4 ,the ,american ,journal of ,science announces the expected visit of ,agassiz as a most promising event for ,american ,zoology 7#a1 #dea1 #ahdf73 8,his devotion1 ability1 and zeal--his high and deserved reputation and 444 his amiable and conciliating character1 will1 without doubt1 secure for him the cordial cooperation of our naturalists 444 nor do we entertain a doubt that we shall be liberally repaid by his able review and exploration of our country40 ,we of to-day can realize how abundantly this prophecy was fulfilled4 ,in the succeeding volume 7#b1 #ddj1 #ahdf7 occurs the record of ,agassiz's arrival4 8,we learn with pleasure that he will spend several years among us1 in order thoroughly to understand our natural history40 ,immediately on reaching ,boston1 ,agassiz began the publication of articles on our fauna1 and the following year he was appointed to a professorship at ,harvard4 ,the ,journal says 7#d1 #ddi1 #ahdg73 8,every scientific man in ,america will be rejoiced to hear so unexpected a piece of good news40 ,the next year the ,journal 7#e1 #aci1 #ahdh7 records ,agassiz's lecture courses at ,new ,york and ,charleston1 his popularity with all classes of the people and the gift of a silver case containing #bej in half eagles from the students of the ,college of ,physicians and ,surgeons4 ,the service of ,agassiz to ,american zoology1 therefore1 consisted not only in the publication of the results of his researches and his philosophical considerations therefrom1 but also1 and perhaps in even greater degree1 in the popularization of science4 ,in the latter direction were his inspiring lectures before popular audiences and the early publication of a zoological text-book4 ,this book1 published in #ahdh1 was entitled 8,principles of ,zoology1 touching the ,structure1 ,development1 ,distribution and ,natural arrangement of the races of ,animals1 living and extinct1 with numerous illustrations40 ,it was written with the cooperation of ,augustus ,a4 ,gould4 ,the review of this book in the ,journal 7#f1 #aea1 #ahdh7 indicates clearly the broad modern principles underlying the new era which was beginning for ,american zoology4 8,a work emanating from so high a source as the ,principles of ,zoology1 hardly requires commendation to give it currency4 ,the public have become acquainted with the eminent abilities of ,prof4 ,agassiz through his lectures1 and are aware of his vast learning1 wide reach of mind1 and popular mode of illustrating scientific subjects 444 ,the volume is prepared for the student in zoological science2 it is simple and elementary in style1 full in its illustrations1 comprehensive in its range1 yet well considered and brought into the narrow compass requisite for the purpose intended40 ,the titles of its chapters will show how little it differs in general subject matter from the most recent text-book in biology4 ,chapter ,i1 ,the ,sphere and fundamental principles of ,zoology2 ,,ii1 ,general ,properties of ,organized ,bodies2 ,,iii1 ,organs and ,functions of ,animal ,life2 ,,iv1 ,of ,intelligence and ,instinct2 ,v1 ,of ,motion 7apparatus and modes72 ,,vi1 ,of ,nutrition2 ,,vii1 ,of the ,blood and ,circulation2 ,,viii1 ,of ,respiration2 ,,ix1 ,of the ,secretions2 ,x1 ,embryology 7,egg and its ,development72 ,,xi1 ,peculiar ,modes of ,reproduction2 ,,xii1 ,metamorphoses of ,animals2 ,,xiii1 ,geographical ,distribution of ,animals2 ,,xiv1 ,geological ,succession of ,animals1 or their ,distribution in ,time4 ,a moment's consideration of the fact that all these topics are excellently treated will show how great had been the progress of zoology in the first half of the nineteenth century4 ,the sixty years that have elapsed since the publication of this book have served principally to develop these separate lines of biology into special fields of science without reorganization of the essential principles here recognized4 ,this remained for many years the standard zoological and physiological text-book1 and was republished in several editions here and in ,england4 ,another popular book is entitled 8,methods of ,study in ,natural ,history0 7#ahfd74 ,more than #djj books and papers were written by ,agassiz1 over a third of which were published before he came to ,america4 ,they cover both zoological and geological topics1 including systematic papers on living and fossil groups of animals1 but most important of all are his philosophical essays on the general principles of biology4 ,one of ,agassiz's greatest services to zoology was the publication of his 8,bibliographia ,zoologi et ,geologi0 by the ,ray ,society1 beginning with #ahdh4 ,the publication of the ,lowell lectures in ,comparative ,embryology in #ahdi gave wide audience to the general principles now recognized in the biogenetic law of ancestral reminiscence4 ,as stated in the ,journal 7#h1 #aeg1 #ahdi71 the 8object of the ,lectures is to demonstrate that a natural method of classifying the animal kingdom may be attained by a comparison of the changes which are passed through by different animals in the course of their development from the egg to the perfect state2 the change they undergo being considered as a scale to appreciate the relative position of the species40 ,these 8principles of classification0 are fully elucidated in a separate pamphlet1 and are discussed at length in the ,journal 7#aa1 #abb1 #ahea74 ,one of the most interesting of ,agassiz's numerous philosophical essays1 originally contributed to the ,journal 7#i1 #cfi1 #ahej71 discusses the 8,natural ,relations between ,animals and the elements in which they live40 ,another philosophical paper contributed to the ,journal discusses the 8,primitive diversity and number of ,animals in ,geological times0 7#ag1 #cji1 #ahed74 ,of his systematic papers1 those on the fishes of the ,tennessee river1 describing many new species1 were published in the ,journal 7#ag1 #big1 #cec1 #ahed74 ,illustration3 ,ls ,agassiz ,agassiz's beautifully illustrated 8,contributions to the ,natural ,history of the ,united ,states0 cover many subjects in morphology and embryology1 which are treated with such thoroughness and breadth of view as to give them a place among the zoological classics4 ,the ,essay on ,classification1 the ,north ,american ,testudinata1 the ,embryology of the turtle1 and the ,acalephs are the special topics4 ,these are summarized and discussed at length in the ,journal 7#be1 #abf1 #bjb1 #cba1 #cdb1 #aheh2 #cj1 #adb1 #ahfj2 #ca1 #bie1 #ahfa74 ,the volume on the 8,journey in ,brazil0 7#ahfh7 in joint authorship with ,mrs4 ,agassiz is a fascinating narrative of exploration4 ,the conceptions which ,agassiz held as to the most essential aim of zoological study are well illustrated in his autobiographical sketch1 where he writes3#agd 8,i did not then know how much more important it is to the naturalist to understand the structure of a few animals1 than to command the whole field of scientific nomenclature4 ,since ,i have become a teacher1 and have watched the progress of students1 ,i have seen that they all begin in the same way2 but how many have grown old in the pursuit1 without ever rising to any higher conception of the study of nature1 spending their life in the determination of species1 and in extending scientific terminology60 ,it is not surprising1 then1 that under such influence the older systematic studies should be replaced in large measure by those of a morphological and embryological nature4 ,the personal influence of ,agassiz is still felt in the lives of even the younger zoologists of the present day4 ,for the investigators of the present generation are for the most part indebted to one or another of ,agassiz's pupils for their guidance in zoological studies4 ,these pupils include his son ,alexander ,agassiz1 ,allen1 ,brooks1 ,clarke1 ,fewkes1 ,goode1 ,hyatt1 ,jordan1 ,lyman1 ,morse1 ,packard1 ,scudder1 ,verrill1 ,wilder1 and others--leaders in zoological work during the last third of the nineteenth century4 ,through such men as these the inspiration of ,agassiz has been handed on in turn to their pupils and from them to the younger generation of zoologists4 ,the essential difference between the work of ,agassiz and that of the ,american zoologists who preceded him was in his power of broad generalizations4 ,to him the organism meant a living witness of some great natural law1 in the interpretation of which zoology was engaged4 ,the organism in its structure1 in its development1 in its habits furnished links in the chain of evidence which1 when completed1 would reveal the meaning of nature4 ,of all ,agassiz's pupils1 probably ,william ,k4 ,brooks most fittingly perpetuated his master's ideals4 ,period of ,morphology and ,embryology1 #ahdg-ahgj4 ,the new aspect of zoology which came as a result of the influence of ,agassiz characterized the zoological work of the fifties and sixties1 that is1 until the significance of the natural selection theory of ,darwin and ,wallace became generally appreciated4 ,the work in these years and well into the seventies was largely influenced by the morphological1 embryological and systematic studies of ,louis ,agassiz and his school4 ,the structure1 development1 and homologies of animals as indicating their relationship and position in the scheme of classification was prominent in the work of this period4 ,the adaptations of animals to their environment and the application of the biogenetic law to the various groups of animals were also favorite subjects of study4 ,the most successful investigators in this period on the different groups of animals include3--,louis ,agassiz on the natural history and embryology of coelenterates and turtles2 ,a4 ,agassiz1 embryology of echinoderms and worms2 ,h4 ,j4 ,clark1 embryology of turtles and systematic papers on sponges and coelenterates2 ,e4 ,desor1 echinoderms and embryology of worms2 ,c4 ,girard1 embryology1 worms1 and reptiles2 ,j4 ,leidy1 protozoa1 coelenterates1 worms1 anatomy of mollusks2 ,w4 ,o4 ,ayres and ,t4 ,lyman1 natural history of echinoderms2 ,mc,crady1 development of acalephs2 ,w4 ,stimpson1 marine invertebrates2 ,a4 ,e4 ,verrill1 coelenterates1 echinoderms1 worms2 ,a4 ,hyatt1 evolutionary theories1 bryozoa and mollusks2 ,pourtales1 deep sea fauna2 ,c4 ,b4 ,adams1 ,a4 and ,w4 ,g4 ,binney1 ,brooks1 ,carpenter1 ,conrad1 ,dall1 ,jay1 ,lea1 ,s4 ,smith1 ,tryon1 mollusks2 ,e4 ,s4 ,morse1 brachiopods1 mollusks2 ,j4 ,d4 ,dana1 coelenterates and ,crustacea2 ,kirtland1 ,loew1 ,edwards1 ,hagen1 ,melsheimer1 ,packard1 ,riley1 ,scudder1 ,walsh1 insects2 ,gill1 ,holbrook1 ,storer1 fishes2 ,cope1 evolutionary theories1 fishes and amphibia2 ,baird1 reptiles and birds2 ,j4 ,a4 ,allen1 amphibia1 reptiles and birds2 ,brewer1 ,cassin1 ,coues1 ,lawrence1 birds2 ,audubon1 ,bachman1 ,baird1 ,cope1 ,wilder1 mammals4 ,the progress of ornithology in the ,united ,states previous to #ahgf is well described in a paper by ,j4 ,a4 ,allen in the ,american ,naturalist 7#aj1 #ecf1 #ahgf74 ,a sketch of the early history of conchology is given by ,a4 ,w4 ,tryon in the ,journal 7#cc1 #ac1 #ahfb74 ,jeffries ,wyman was the most prominent comparative anatomist of this period4 ,his work includes classic papers on the anatomy and embryology of fishes1 amphibia1 and reptiles4 ,zoology in the ,american ,journal of ,science1 #ahdf-ahgj4 ,the fifty volumes of the second series of the ,journal1 including the years #ahdf to #ahgj1 cover approximately this period of morphology and embryology4 ,during this period the ,journal occupied a very important place in zoological circles1 for ,j4 ,d4 ,dana was for most of this period the editor-in-chief1 while ,louis ,agassiz and ,asa ,gray were connected with it as associate editors4 ,moreover1 in #ahfd one of the most promising of ,agassiz's pupils1 ,addison ,e4 ,verrill1 was called to ,yale as professor of zoology and was made an associate editor in #ahfi4 ,in the ,journal1 therefore1 may be found1 in its original articles1 together with its reports of meetings and addresses and its reviews of literature1 a fairly complete account of the zoological activity of the period4 ,the most important zoological researches1 both in ,europe and ,america1 were reviewed in the bibliographic notices4 ,the most important series of zoological articles are by ,dana himself4 ,as his work on the zoophytes and crustacea of the ,u4 ,s4 ,exploring ,expedition continued1 he published from time to time general summaries of his conclusions regarding the relationships of the various groups4 ,included among these papers are philosophical essays on general biological principles which must have had much influence on the biological studies of the time1 and which form a basis for many of our present concepts4 ,the importance of these papers warrants the list being given in full4 ,the titles are here in many cases abbreviated and the subjects consolidated4 ,general views on ,classification1 #a1 #bhf1 #ahdf4 ,zoophytes1 #b1 #fd1 #ahg1 #ahdf2 #c1 #a1 #afj1 #ccg1 #ahdg4 ,genus ,astraea1 #i1 #bie1 #ahej4 ,conspectus crustaceorum1 #h1 #bgf1 #dbd1 #ahdi2 #i1 #abi1 #ahej2 #aa1 #bfh1 #ahea4 ,genera of ,gammaracea1 #h1 #ace1 #ahdi2 of ,cyclopacea1 #a1 #bbe1 #ahdf4 ,markings of ,carapax of ,crabs1 #aa1 #ie1 #ahea4 ,classification of ,crustacea1 #aa1 #bbc1 #dbe2 #ab1 #aba1 #bch1 #ahea2 #ac1 #aai2 #ad1 #big1 #aheb2 #bb1 #ad1 #ahef4 ,geographical distribution of ,crustacea1 #ah1 #cad1 #ahed2 #ai1 #f2 #bj1 #afh1 #cdi1 #ahee4 ,alternation of ,generations in ,plants and ,radiata1 #aj1 #cda1 #ahej4 ,parthenogenesis1 #bd1 #cii1 #aheg4 ,on ,species1 #bd1 #cje1 #aheg4 ,classification of ,mammals1 #ce1 #fe1 #ahfc2 #cg1 #aeg1 #ahfd4 ,cephalization1 #bb1 #ad1 #ahef2 #cf1 #a1 #cba1 #ddj1 #ahfc2 #cg1 #aj1 #aeg1 #ahd1 #ahfd2 #da1 #afc1 #ahff2 #ab1 #bde1 #ahgf4 ,homologies of insectean and crustacean types1 #cf1 #bcc1 #ahfc2 #dg1 #cbe1 #ahid4 ,origin of life1 #da1 #chi1 #ahff4 ,relations of death to life in nature1 #cd1 #caf1 #ahfb4 ,of the above1 the articles on cephalization as a fundamental principle in the development of the system of animal life have attracted much attention4 ,the evidence from comparative anatomy1 paleontology1 and embryology alike supports the view that advance in the ontogenetic as well as in the phylogenetic stages is correlated with the unequal growth of the cephalic region as compared with the rest of the body4 ,dana shows that this principle holds good for all groups of animals4 ,his homologies of the limbs of arthropods and vertebrates1 however1 do not accord with more modern views4 ,other papers on the same and allied topics were published by ,dana in other periodicals4 ,his most conspicuous zoological works1 however1 are his reports on the ,zoophytes and ,crustacea of the ,united ,states ,exploring ,expedition1 #ahcg-ahdb4 ,the former consists of #gda quarto pages and #fa folio plates1 describing over #bjj new species1 while the ,crustacea report1 in two volumes1 has #afbj pages and #if folio plates1 with descriptions of about #ejj new species4 ,each of these remains to-day as the most important contribution to the classification of the respective groups4 ,the relationships of the species1 genera and families were recognized with such remarkable judgment that ,dana's admirable system of classification has remained the basis for all subsequent work4 ,dana's critical reviews 7#be1 #bjb1 #cba1 #aheh7 of ,agassiz's 8,contribution to the ,natural ,history of the ,united ,states0 are among the most interesting of his philosophical discussions concerning the relationships of animals as revealed by their structure1 their embryology1 and their geological history4 ,the remaining zoological articles in this series cover nearly the whole range of systematic zoology4 ,especially important are the articles by ,verrill on coelenterates1 echinoderms1 worms and other invertebrates4 ,in the years following the publication of ,darwin's ,origin of ,species in #ahei occur many articles on the theory of natural selection4 ,some of the writers attack the theory1 while others give it more or less enthusiastic support4 ,experimental methods in solving biological problems were little used at this time1 although a few articles of this nature appear in the ,journal4 ,of these1 a paper by ,w4 ,c4 ,minor 7#ce1 #ce1 #ahfc7 on natural and artificial fission in some annelids has considerable interest to-day4 ,exploring ,expeditions4 ,of the important zoological expeditions the following may be selected as showing their influence on ,american ,zoology3 ,the ,north ,pacific ,expedition1 with ,william ,stimpson as zoologist1 returned in #ahef with much new information concerning the marine life of the coasts of ,alaska and ,japan and many new species of invertebrates4 ,in #ahfg-ahfi the ,united ,states ,coast ,survey extended its explorations to include the deep sea marine life off the southeastern coasts and ,gulf of ,mexico under the leadership of ,pourtales and ,agassiz4 ,the ,challenger explorations 7#ahgb-ahgf7 added greatly to the knowledge of marine life off the ,american coast as well as in other parts of the world4 ,the explorations of the ,united ,states ,fish ,commission succeeded those of the ,coast ,survey in the collection of marine life off our coasts and in our fresh waters4 ,these have continued since #ahgb and have yielded most important results from both the scientific and economic standpoints4 ,under the charge of ,alexander ,agassiz the ,coast ,survey ,steamer 8,blake10 in #ahgg to #ahhj1 was engaged in dredging operations in three cruises to various parts of the ,atlantic4 ,the ,u4 ,s4 ,fish ,commission ,steamer 8,albatross10 also in charge of ,agassiz1 made three expeditions in the tropical and other parts of the ,pacific in the years from #ahia to #aije4 ,the study of these collections has added greatly to our knowledge of systematic zoology and geographical distribution4 ,the reports on some of the groups are still in course of preparation4 ,period of ,evolution1 #ahgj-ahij4 ,the time from #ahgj to #ahij may be appropriately called the period of evolution1 for although it commences eleven years after the publication of the ,origin of ,species1 the importance of the natural selection theory was but slowly receiving general recognition4 ,the hesitation in accepting this theory was due in no small degree to the opposition of ,louis ,agassiz4 ,after the acceptance of evolution1 although morphological and embryological studies continued as before1 they were prosecuted with reference to their bearing on evolutionary problems4 ,following closely the methods which had produced so much progress during the life of ,agassiz1 the field of zoology was now occupied by a new generation1 among whom the pupils of ,agassiz were the most prominent4 ,illustration3 ,thomas ,h4 ,huxley ,the teaching of biology at this time was also strongly influenced by ,huxley1 whose methods of conducting laboratory classes for elementary students were adopted in most of our large schools and colleges4 ,this placed biology on the same plane with chemistry as a means for training in laboratory methods and discipline1 with the added advantage that the subject of biology is much more intimately connected with the student's everyday life and affairs4 ,this increasing demand for instruction in biology and the consequent necessity for more teachers brought an increasing number of investigators into this field4 ,conspicuous in this period was the work of ,e4 ,d4 ,cope1 best known as a paleontologist1 but whose work on the classification of the various groups of vertebrates stands preeminent1 and whose philosophical essays on evolution had much influence on the evolutionary thought of the time4 ,he was a staunch supporter of the ,lamarckian doctrine4 ,alpheus ,hyatt also maintained this theory1 and brought together a great accumulation of facts in its support4 ,he thereby contributed largely to our knowledge of comparative anatomy and embryology4 ,a4 ,s4 ,packard1 whose publications cover a wide range of topics1 was best known for his text-books of zoology and his manuals on insects4 ,w4 ,k4 ,brooks was a leading morphologist and embryologist4 ,s4 ,f4 ,baird1 for many years the head of the ,united ,states ,fish ,commission1 was the foremost authority on fish and fisheries and is also noted for his work on reptiles1 birds and mammals4 ,the man of greatest influence1 although by no means the greatest investigator1 was ,c4 ,o4 ,whitman4 ,it is to him that we owe the inception of the ,marine ,biological ,laboratory1 the most potent influence in ,american zoology to-day2 the organization of the ,american ,morphological ,society1 the forerunner of the present ,american ,society of ,zoologists2 and the establishment of the ,journal of ,morphology4 ,g4 ,b4 ,goode was distinguished for his work on fishes and for his writings on the history of science4 ,e4 ,l4 ,mark1 ,c4 ,s4 ,minot1 and ,alexander ,agassiz were acknowledged leaders in their special fields of research--,mark in invertebrate morphology and embryology1 and ,minot in vertebrate embryology1 while ,alexander ,agassiz made many important discoveries in the systematic zoology and embryology of marine animals1 and to him we owe in large measure our knowledge of the life in the oceans of nearly all parts of the world4 ,the knowledge of the representatives of the different divisions of the ,american fauna had now become sufficient to allow the publication of monographs on the various classes1 orders and families4 ,at this time also particular attention was given to the marine invertebrates of all groups4 ,of the many investigators working on the various groups of animals at this time only a few may be mentioned4 ,the protozoa were studied by ,leidy1 ,clark1 ,ryder1 ,stokes2 the sponges by ,clark1 ,hyatt2 the coelenterates by ,a4 ,agassiz1 ,s4 ,f4 ,clarke1 ,verrill2 the echinoderms by ,a4 ,agassiz1 ,brooks1 ,kingsley1 ,fewkes1 ,lyman1 ,verrill2 the various groups of worms by ,benedict1 ,eisen1 ,silliman1 ,verrill1 ,webster1 ,whitman2 the mollusks by ,a4 and ,w4 ,g4 ,binney1 ,tryon1 ,conrad1 ,dall1 ,sanderson ,smith1 ,stearns1 ,verrill2 the ,brachiopods by ,dall and ,morse2 the ,bryozoa by ,hyatt2 the crustacea by ,s4 ,i4 ,smith1 ,harger1 ,hagen1 ,packard1 ,kingsley1 ,faxon1 ,herrick2 the insects by ,packard1 ,horn1 ,scudder1 ,c4 ,h4 ,fernald1 ,williston1 ,norton1 ,walsh1 ,fitch1 ,j4 ,b4 ,smith1 ,comstock1 ,howard1 ,riley and many others2 spiders by ,emerton1 ,marx1 ,mc,cook2 tunicates by ,packard and ,verrill2 fishes by ,baird1 ,bean1 ,cope1 ,gilbert1 ,gill1 ,goode1 ,jordan1 ,putnam2 amphibians and reptiles by ,cope2 birds by ,baird1 ,brewer1 ,coues1 ,elliott1 ,henshaw1 ,allen1 ,merriam1 ,brewster1 ,ridgway2 and the mammals by ,allen1 ,baird1 ,cope1 ,coues1 ,elliott1 ,merriam1 ,wilder4 ,interest in the evolutionary theory continued to increase and eventually developed into the morphological and embryological studies which reached their culmination between #ahhe and #ahij under the guidance of ,whitman1 ,mark1 ,minot1 ,brooks1 ,kingsley1 ,e4 ,b4 ,wilson and other famous zoologists of the time4 ,in these years the ,journal of ,morphology was established and the ,american ,morphological ,society was formed4 ,the morphological1 embryological and paleontological evidences of evolution as indicated by homologies1 developmental stages and adaptations were the most absorbing subjects of zoological research and discussion4 ,illustration3 ,a4 ,e4 ,verrill ,march #aijd ,zoology in the ,american ,journal of ,science1 #ahgj-aiah4 ,the third series of the ,journal 7#ahgj-ahie71 likewise including fifty volumes1 embraces this period of zoological activity in morphological and embryological studies1 culminating with the inception of the modern experimental methods4 ,in this period also occurred the greatest progress in marine systematic zoology1 due to the explorations of the ,united ,states ,fish ,commission off the ,atlantic ,coast4 ,the ,journal had an important share in the zoological development of this period also1 for ,a4 ,e4 ,verrill1 who was now an associate editor1 was in charge of the collections of marine invertebrates4 ,consequently most of the discoveries in this field were published in the ,journal in numerous original contributions by ,verrill and his associates4 ,the explorations of the ,u4 ,s4 ,fish ,commission ,steamer 8,albatross0 are described from year to year by ,verrill1 with descriptions of the new species of invertebrates discovered4 ,the numerous original contributions by ,verrill on subjects of general zoological interest as well as on those of a systematic nature give this third series of the ,journal much zoological importance4 ,verrill's papers cover almost the whole field of descriptive zoology1 but are mainly devoted to marine invertebrates4 ,those which were originally contributed to the ,journal or summarized by him in his literature reviews include the following topics3 ,sponges1 #af1 #djf1 #ahgh4 ,coelenterates1 #cg1 #dej1 #ahfd2 #dd1 #abe1 #ahfg2 #de1 #daa1 #ahf2 #df1 #adc1 #ahfh2 #dg1 #bhb1 #ahfi2 #dh1 #aaf1 #dai1 #ahfi2 #di1 #cgj1 #ahgj2 #c1 #ahg1 #dcb1 #ahgb2 #f1 #fh1 #ahgc2 #ba1 #ejh1 #ahha2 #f1 #dic1 #ahih2 #g1 #da1 #adc1 #bje1 #cge1 #ahii2 #ac1 #ge1 #aijb4 ,echinoderms1 #dd1 #abe1 #ahfg2 #de1 #dag1 #ahfh2 #di1 #ic1 #aja1 #ahgj2 #b1 #dcj1 #ahga2 #aa1 #daf1 #ahgf2 #di1 #abg1 #aii1 #ahie2 #bh1 #ei1 #aiji2 #ce1 #dgg1 #aiac2 #cg1 #dhc1 #aiad2 #ch1 #ajg1 #aiad2 #ci1 #fhd1 #aiae4 ,worms1 #ej1 #bbc1 #ahgj2 #c1 #abf1 #ahgb4 ,mollusks1 #di1 #bag1 #ahgj2 #ej1 #dje1 #ahgj2 #c1 #bji1 #bha1 #ahgb2 #e1 #dfe1 #ahgc2 #g1 #acf1 #aeh1 #ahgd2 #i1 #abc1 #agg1 #ahge2 #aj1 #bac1 #ahge2 #ab1 #bcf1 #ahgf2 #ad1 #dbe1 #ahgg2 #ai1 #bhd1 #ahhj2 #bj1 #bej1 #bea1 #ahhj2 #b1 #gd1 #ia1 #ahif2 #c1 #ea1 #gi1 #afb1 #cee1 #ahig4 ,crustacea1 #dd1 #abf1 #ahfg2 #dh1 #bdd1 #dcj1 #ahfi2 #be1 #aai1 #ecd1 #aijh4 ,ascidians1 #a1 #ed1 #ic1 #baa1 #bhh1 #ddc1 #ahga2 #bj1 #bea1 #ahhj4 ,dredging operations and marine fauna1 #di1 #abi1 #ahgj2 #b1 #ceg1 #ahga2 #e1 #a1 #ih1 #ahgc2 #f1 #dce1 #ahgc2 #g1 #ch1 #aca1 #dje1 #dji1 #dih1 #fjh1 #ahgd2 #i1 #daa1 #ahge2 #aj1 #cf1 #aif1 #ahge2 #af1 #bjg1 #cga1 #ahgh2 #ag1 #bci1 #beh1 #cji1 #dgb1 #ahgi2 #ah1 #eb1 #dfh1 #ahgi2 #ai1 #acg1 #ahg2 #bj1 #cij1 #ahhj2 #bb1 #bib1 #ahha2 #bc1 #ace1 #baf1 #cji1 #djf1 #ahhb2 #bd1 #cfj1 #dgg1 #ahhb2 #bh1 #bac1 #cgh1 #ahhd2 #bi1 #adi1 #ahhe4 ,miscellaneous1 #ci1 #bba1 #ahfe2 #da1 #bdi1 #bfh1 #ahff2 #dd1 #abf1 #ahfg2 #dh1 #ib1 #ahfi2 #c1 #chf1 #ahgb2 #g1 #acd1 #ahdg2 #aj1 #cfd1 #ahge2 #af1 #cbc1 #ahgh2 #bj1 #bea1 #ahhj2 #c1 #acb1 #ace1 #ahig2 #i1 #cac1 #aijj2 #ab1 #hh1 #aija2 #ac1 #cbg1 #aijb2 #ad1 #gb1 #aijb2 #ae1 #ccb1 #aijc2 #bd1 #agi1 #aijg2 #bi1 #efa1 #aiaj4 ,s4 ,i4 ,smith describes the metamorphosis of the ,crustacea 7#c1 #dja1 #ahgb2 #f1 #fg1 #ahgc71 species of crustacea 7#c1 #cgc1 #ahgb2 #g1 #fja1 #ahgd2 #i1 #dgf1 #ahge71 and dredging operations in ,lake ,superior 7#b1 #cgc1 #ddh1 #ahga74 ,in this series occurs also a series of papers on comparative anatomy and embryology from the ,chesapeake ,zoological ,laboratory in charge of ,w4 ,k4 ,brooks4 ,in the #cith and #djth volumes of the third series 7#ahij7 occur several papers on evolutionary topics by ,john ,t4 ,gulick 7#ci1 #ba2 #dj1 #a1 #dcg7 which have attracted much attention4 ,before the end of this period1 however1 the ,journal was relieved from the necessity of publishing zoological articles by the establishment of several periodicals devoted especially to the various fields of zoology4 ,we find1 therefore1 but few exclusively zoological papers after #ahhe1 although articles of a general biological interest and the reviews of zoological books continue4 ,in the fourth series of the ,journal1 beginning in #ahif1 occur also a number of articles on systematic zoology by ,verrill and others and several papers having a general biological interest4 ,brief reviews of a small number of zoological books are still continued1 but at the present day the ,journal1 which played so important a part in the early development of ,american zoology1 has been given over to the geological and physical sciences in harmony with the modern demand for specialization4 ,period of ,experimental ,biology1 since #ahij4 ,zoological studies remained in large measure observational and comparative until about #ahij when the experimental methods of ,roux1 ,driesch and others came into prominence4 ,interest then turned from the accumulation of facts to an analysis of the underlying principles of biological phenomena4 ,the question now was not so much what the organism does as how it does what is observed1 and this question could be answered only by the experimental control of the conditions4 ,these experimental studies met with such remarkable success that in a few years the older morphological studies were largely abandoned1 the ,morphological ,society changed its name to the ,society of ,zoologists1 and in #aijd the ,journal of ,experimental ,zoology was established4 ,the experimental methods were applied to all branches of biological science1 and while it must be freely admitted that little progress has been made toward an understanding of the ultimate causes which underlie biological phenomena1 a great advance has been made in the elucidation of the general principles involved4 ,experimental embryology1 histology1 regeneration1 comparative physiology1 neurology1 cytology1 and heredity have in recent years successfully adopted an experimental aspect and have made significant progress thereby4 ,biology has now taken its place beside chemistry and physics as an experimental science4 ,the latest great advance in biology has been in the field of heredity4 ,the rediscovery of the ,mendelian principles of heredity in #aijj brought to light the most important generalization in biology in recent times4 ,the new science of genetics is essentially the experimental study of heredity4 ,we are at the moment in the midst of an effort to establish in biology a few relatively simple laws by using for the purpose the vast accumulations of observational data gathered in past years1 supplemented by such experimental data as have been provided by these more recent investigations4 ,such hypotheses as have been formulated are for the most part only tentatively held1 for their validity is generally incapable of a critical test4 ,but wherever such tests have been possible1 the laws of mathematics1 physics and chemistry are found applicable to biological phenomena4 ,the number of investigators has now become so great and their activities so prolific that the list and synopses of the zoological publications each year cover upwards of #ajjj to #aejj pages in the ,international ,catalogue of ,scientific ,literature4 ,american ,leadership4--,during the first half of the century the progress of zoology in ,america remained distinctly behind that of ,europe4 ,at the beginning of the century the science was farthest developed by the ,french and ,english1 although ,linnus was a ,swede and took his degree in ,holland4 ,under the influence of ,von ,baer and his monumental treatise on embryology 7,ueber ,entwicklungsgeschichte der ,thiere1 #ahbh71 and supported later by the great physiologist1 ,johannes ,mller1 whose 8,physiologie des ,menschen0 7#ahdf7 forms the basis of modern physiology1 the ,german school forged rapidly ahead and eventually assumed the leadership in zoology1 as in several other branches of science4 ,in the latter half of the century the influence of the ,german universities dominated in a large measure the zoological investigations in ,america4 ,the reason for this is partly due to the fact that many of our young zoologists1 after finishing their college course1 completed their preparation for research by a year or more at a ,german university4 ,the more mature zoologists1 too1 looked forward with keen anticipation to spending their summer vacations and sabbatical years in research in a ,german laboratory or at the famous ,naples station in which the ,german influence was dominant4 ,with the rise of experimental biology since #ahij1 however1 the ,american zoologists have shown so high a degree of originality in devising experiments1 so much skill in performing them1 and such keenness in analyzing the results1 that they have assumed the world leadership in several of the special fields into which the science of zoology is now divided4 ,biological ,periodicals4 ,perhaps in no better way can the progress of biology in ,america be illustrated than by a brief survey of the origin and development of the more important biological journals4 ,for it will be seen that these publications have become more numerous and more specialized as the science has advanced in specialization4 ,the early publications--which as is well known1 treated mainly of the birds1 mammals and other vertebrates1 and of insects1 crustacea and shells--consisted mainly of separate books or pamphlets1 published by private subscription4 ,after the establishment of the so-called ,academies of ,science1 or of ,arts and ,sciences1 toward the end of the eighteenth and in the first quarter of the nineteenth century1 the reports of the meetings began to be published as periodical ,journals1 supported by the academies4 ,in these publications1 and in the ,journal which was founded at the same time1 appear papers on all branches of science1 including zoology4 ,as soon as zoology in ,america assumed its modern aspects through the influence of ,louis ,agassiz and his followers the earliest strictly zoological journals were established4 ,it should be noted1 however1 that the journals of the scientific and natural history societies were more or less fully devoted to zoological topics according to the nature of the activities of the members and correspondents4 ,after the establishment of the ,museum of ,comparative ,zoology by ,louis ,agassiz came the founding in #ahfc of its ,bulletin and later its ,memoirs4 ,these publications have continued to the present day as a standard of excellence for the reports of zoological investigations4 ,in connection with the systematic work on mollusks1 the ,american ,journal of ,conchology was established in #ahfe4 ,the ,american ,naturalist was founded in #ahfg by four of ,louis ,agassiz's pupils1 ,hyatt1 ,morse1 ,packard and ,putnam4 ,it was later edited by ,cope as a leading periodical for the publication of biological papers1 particularly those relating to evolution1 and is at present devoted to evolutionary topics4 ,it is now in the #eb;d volume of its new series4 ,with the awakened interest in comparative anatomy and embryology came the need for an ,american journal which should supply a means of publication for the reports of researches accomplished by the increasing number of workers in these fields4 ,this need was fully met by the establishment of the ,journal of ,morphology in #ahhg4 ,this publication1 now in its #cjth volume1 has equalled the best ,european journals in the character of its papers4 ,a few years later 7#ahia7 came the ,journal of ,comparative ,neurology for the publication of investigations relating to the morphology and physiology of the nervous system and to nervous and allied phenomena in all groups of organisms4 ,twenty-eight volumes of this journal have been completed4 ,the ,zoological ,bulletin was started under the auspices of the ,marine ,biological ,laboratory in #ahig for the publication of papers of a less extensive nature and which could be more promptly issued than those in the ,journal of ,morphology where elaborate plates were required4 ,after two years the scope of the ,bulletin was enlarged to include botanical and physiological subjects4 ,the name was correspondingly changed to the ,biological ,bulletin4 ,of this important periodical #cc volumes have been issued4 ,for the publication of papers on human and comparative anatomy and embryology1 the ,american ,journal of ,anatomy was established in #aija1 and is now in its twenty-third volume4 ,meanwhile the trend of zoological interest was toward topics connected with the ultimate nature of biological phenomena4 ,the meaning of these phenomena could be determined only by the experimental method4 ,researches in this field became more prominent and the adequate publication of the numerous papers required the establishment of a new journal in #aijd4 ,this was named the ,journal of ,experimental ,zoology4 ,it immediately took its place in the front rank of ,american zoological periodicals4 ,twenty-four volumes have been published4 ,in spite of the constantly increasing number of journals1 the science grew faster than the means of publication4 ,so crowded did the ,american journals become that long delays often resulted before the results of an investigation could be issued4 ,this condition was met in part by the sending of many papers to be published in ,european journals 7a necessity most discreditable to ,american zoology7 and in part by the establishment of additional means of publication4 ,of the latter the ,anatomical ,record1 now in its fourteenth volume1 was begun in #aijf for the prompt publication of briefer papers on vertebrate anatomy1 embryology and histology and for preliminary reports and notes on technique4 ,during the past few years has come a great advance in the experimental breeding of plants and animals4 ,problems in heredity and evolution have taken on a new interest since the importance and validity of ,mendel's discovery have been recognized4 ,to meet this development of biology the journal ,genetics was begun in #aiaf for the publication of technical papers1 while the ,journal of ,heredity1 modified from the ,american ,breeders ,magazine1 is devoted to popular articles on animal and plant breeding1 and ,eugenics4 ,on the whole1 the science of zoology is now assuming a closer relation to practical affairs4 ,entomology1 for example1 is now represented by the ,journal of ,economic ,entomology1 of which #aj volumes have been issued since #aijg4 ,the ,journal of ,animal ,behavior covers another practical field of research4 ,the ,proceedings of the ,society for ,experimental ,biology and ,medicine1 starting in #aijc1 the ,american ,journal of ,physiology1 and several other publications cover the physiological field4 ,the ,journal of ,parasitology1 established #aiad1 now in its fourth volume1 is devoted to the interests of medical zoology4 ,the ,auk1 now in the #cdth volume of its new series 7#db;d of old series71 is the official organ of the ,american ,ornithologists ,union and is devoted to the dissemination of knowledge concerning bird life4 ,the ,annals of the ,entomological ,society of ,america1 established in #aijh1 and now in its #ajth volume1 is one of several important entomological journals4 ,the ,nautilus1 of which #bh volumes have been issued1 is one of the more successful journals devoted to conchology4 ,this list might be extended to include numerous other periodicals of importance1 both technical and popular1 which have been of great service in the various fields of biology4 ,in addition to these are the many volumes of systematic papers in the ,proceedings of the ,united ,states ,national ,museum1 the practical reports in the ,bulletin of the ,united ,states ,fish ,commission1 the vast literature issued yearly by the various divisions of the ,united ,states ,department of ,agriculture1 ,public ,health ,service and other ,governmental departments1 while the list of publications by scientific societies1 museums1 and other institutes is constantly increasing and covers all fields of biological research4 ,at the present time facilities for the publication of research on any branch of zoology are as a rule entirely adequate4 ,for this highly satisfactory condition the science is indebted to the support given five of its most important journals by the ,wistar ,institute of ,anatomy and ,biology4 ,biological ,associations4 ,an important light on the history of biology in ,america can be thrown by a glance at the rise and development of societies or associations for the report and discussion of papers relating to that branch of science4 ,in the first half of the nineteenth century natural history societies were formed in most cities and centers of learning4 ,these were very important factors in the promotion of scientific research as well as in the diffusion of popular knowledge of living things4 ,the aims and activities of twenty-nine such scientific societies1 many of which were devoted especially to natural history1 are described in one of the early volumes of the ,journal 7#aj1 #cfi1 #ahbf74 ,the ,connecticut ,academy of ,arts and ,sciences1 dating from #agii1 the ,philadelphia ,academy of ,natural ,sciences from #ahab1 and the ,new ,york ,lyceum of ,natural ,history 7in #ahgf name changed to ,new ,york ,academy of ,sciences7 from #ahag are among the oldest of those which still exist4 ,of national institutions the ,american ,philosophical ,society was founded in #agdc1 the ,american ,academy of ,arts and ,sciences in #aghj1 and the ,national ,academy of ,sciences in #ahfc4 ,the ,american ,association for the ,advancement of ,science1 with its thousands of members1 now has separate sections for each of the special branches of science4 ,this great association was organized in #ahdh1 as the successor of the ,association of ,american ,geologists and ,naturalists4 ,this was itself a revival of the ,american ,geological ,society which first met at ,yale in #ahai4 ,its meetings have given a great support to the scientific work of the country4 ,the ,american ,society of ,naturalists was founded in #ahhc4 ,the original plan of the society was for the discussion of methods of investigation1 administration and instruction in the natural sciences1 but its program is now entirely devoted to discussions and papers of a broad biological interest4 ,it also arranges for an annual dinner of the several biological societies and an address on some general biological topic4 ,in #ahij1 toward the end of the period in which morphological studies were being emphasized1 the professional zoologists of the eastern states founded the ,american ,morphological ,society4 ,this association held annual meetings during the ,christmas holidays for the presentation of zoological papers4 ,this name became less appropriate after a few years because of the gradual decrease in the proportion of morphological investigations owing to the greater attention being directed to problems in experimental zoology and physiology4 ,consequently the name was changed to the ,american ,society of ,zoologists4 ,to be eligible for membership in this society a person must be an active investigator in some branch of zoology1 as indicated by the published results4 ,the ,american ,association of ,anatomists includes in its membership investigators and teachers in comparative anatomy1 embryology1 and histology as well as in human anatomy4 ,many professional zoologists and experimental biologists present their papers before this society1 or at the meetings of the ,american ,physiological ,society4 ,the ,entomological ,society of ,america and the ,american ,association of ,economic ,entomologists are large and active societies4 ,these national societies have been of great service in fostering a high standard of zoological research4 ,a still more important service1 though generally less conspicuous1 is rendered by the journal clubs in connection with all the larger zoological laboratories1 and by local scientific societies which are now maintained in all the larger centers of learning throughout the country4 ,there are also specific societies for some of the different fields of biological work4 ,biological ,stations4 ,no insignificant factor in the development of biological science has been the establishment of biological stations where investigators1 teachers and students meet in the ,summer vacation for special studies1 discussions and research4 ,the most successful of these laboratories have been located on the seashore and here the study of marine life in ,summer supplements the work of the school or university biological courses4 ,the famous ,naples ,station was founded in #ahgj1 and was shortly after followed by several others4 ,similar biological stations are now supported on almost every coast in ,europe and in several inland localities4 ,the first such ,american school was established by ,louis ,agassiz at the island of ,penikese on the coast of ,massachusetts in #ahgc1 succeeding his private laboratory at ,nahant4 ,during that ,summer more than forty students gained enthusiasm for the work of future years4 ,unfortunately the laboratory so auspiciously started was of brief duration1 for the death of ,agassiz occurred in ,december of the same year1 and the laboratory was discontinued at the end of the following ,summer4 ,shortly afterward ,alexander ,agassiz equipped a small private laboratory at ,newport1 ,rhode ,island1 and ,w4 ,k4 ,brooks established the ,chesapeake ,bay ,zoological ,laboratory4 ,at this time the ,united ,states ,fish ,commission was engaged under the direction of ,spencer ,f4 ,baird in a survey of the marine life of the waters off the ,eastern ,coast4 ,between #ahha and #ahhf the ,commission established the splendidly equipped biological station at ,woods ,hole1 ,massachusetts4 ,both here and at the ,fish ,commission ,laboratory at ,beaufort1 ,north ,carolina1 much work in general zoology as well as in economic problems is accomplished4 ,these laboratories are designed particularly for specialists engaged in researches connected with the work of the ,fish ,commission4 ,a need was soon felt for a marine laboratory along broader lines1 and one available to the students and teachers of the schools and colleges4 ,to meet these requirements the ,woods ,hole ,marine ,biological ,laboratory was started in #ahhg1 as the successor to an earlier laboratory at ,annisquam1 and has since become a great ,summer congress for biologists from all parts of the country4 ,it is safe to say that no other institution has been of equal service in securing for biology the high plane it now occupies in ,american science4 ,the leading spirit in the establishment of this laboratory and its director for many years was ,charles ,o4 ,whitman4 ,successful marine laboratories are located also at ,cold ,spring ,harbor1 ,long ,island2 at ,harpswell1 ,maine2 and at ,bermuda4 ,the ,carnegie ,institution maintains a laboratory at ,tortugas ,island1 ,florida1 for the investigation of tropical marine life4 ,on the ,pacific ,coast marine laboratories are located at ,pacific ,grove and at ,la ,jolla1 ,california1 and at ,friday ,harbor1 ,washington4 ,several other biological laboratories are open each ,summer on our coasts1 as well as a number of fresh-water laboratories on the interior lakes4 ,there are also several mountain laboratories4 ,the influence of these laboratories on ,american biology is immeasurable4 ,natural ,history ,museums4 ,museums of ,natural ,history or 8,cabinets of ,natural ,curios0 as they were sometimes called1 were established in the first half of the nineteenth century in connection with the various natural history societies4 ,these were of much service in stimulating the collection of zoological 8specimens0 and in arousing a popular interest in natural history4 ,the zoological museum of earlier days consisted of rows on rows of systematically arranged specimens1 each carefully labelled with scientific name1 locality1 date of collection and donor--much like the pages of a catalogue4 ,all this has now been changed2 the bottles of specimens have been relegated to the storeroom1 and the great plate glass cases of the modern museum represent individual studies in the various fields of modern zoological research1 or individual chapters in the latest biological text-books4 ,often the talent of the artist and the skill of the taxidermist are cunningly combined to produce most realistic bits of nature4 ,the ,united ,states ,national ,museum1 the ,american ,museum of ,natural ,history1 the ,field ,columbian ,museum and the ,museum of ,comparative ,zoology are among the finest museums of the world1 while many of the states1 cities1 and universities maintain public museums as a part of their educational systems4 ,systematic ,zoology and ,taxonomy4 ,the work in systematic zoology is now mainly carried on by specialists in relatively small groups of animals4 ,this is necessitated both by the increasingly large number of species known to science and by the completeness and exactness with which species must now be defined4 ,the majority of systematic workers are now connected with museums where the large collections furnish material for comparative studies4 ,prominent in this field is the ,united ,states ,national ,museum1 the publications of which are mainly taxonomic and zoogeographic1 and cover every group of organism4 ,the adequacy of this great museum for such studies may be illustrated by the collection of mammals4 ,this museum has the types of #aace of the #bach forms 7including species and subspecies7 of ,north ,american mammals recognized in ,miller's list1#age and less than #bjj forms lack representatives among the #abj1jjj specimens of mammals4 ,systematic monographs of several of the orders of mammals have been published4 ,systematic study of the birds has brought the number of species and subspecies known to inhabit ,north and ,middle ,america to above #cjjj4 ,the most comprehensive systematic treatise is the still incomplete report of ,ridgeway#agf of which seven large volumes have already been issued4 ,on the reptiles1 the most complete monograph is that by ,cope#agg entitled 8,the ,crocodilians1 ,lizards and ,snakes of ,north ,america40 ,the ,amphibia have also been studied by ,cope1 whose report on the ,batrachia of ,north ,america#agh is the standard taxonomic work4 ,the most comprehensive systematic work on fishes is the 8,descriptive ,catalogue of the ,fishes of ,north and ,middle ,america0 by ,jordan and ,evermann4#agi ,the invertebrate groups have been in part similarly monographed by the members of the ,u4 ,s4 ,national ,museum staff and others1 and further studies are in progress4 ,other taxonomic monographs published by this museum include the various groups of animals from many different parts of the world4 ,a number of the larger ,state1 municipal1 and university museums publish bulletins on special groups represented in their collections as well as articles of general zoological interest4 ,expeditions1 subsidized by museum and private funds1 are from time to time sent to various parts of the world and their results are often published in sumptuous manner4 ,the total number of living species of animals is unknown1 but considering that about a quarter of a million new species have been described during the past thirty years1 it is probable that several million species are in existence to-day4 ,more than half a million have been described4 ,these are probably but a small fraction of the number that have existed in past geological ages4 ,thus1 in spite of all the work that has been done in systematic zoology and as the number of known species continues to increase1 there still remain many groups of animals1 some of which are by no means rare or minute1 in which probably only a small proportion of the species are as yet capable of identification4 ,it is only since the publication of ,ward and ,whipple's 8,fresh-water ,biology0 within the past year that the amateur zoologist could hope to find even the names of all the organisms which may be collected from a single pool of water4 ,and in many cases he will still meet with disappointment1 for many of our protozoa and other fresh-water organisms have not yet been described as species4 ,during the past few years there has been a tendency on the part of some of our biologists engaged in experimental work to disparage the studies of the systematists4 ,it must be granted1 however1 that both lines of work are essential to the sound development of zoological science1 for experimental investigations in which the accurate diagnosis of species is ignored always result in confusion4 ,ecology4--,the marvelous modifications in structure and instincts by which the various animals are adapted to their surroundings now forms a special topic in biological research and one of the most fascinating4 ,the adaptations in habitat1 time1 behavior1 appearance and even in structure are found capable of a certain individual modification when studied experimentally4 ,zoogeography4--,closely associated with systematic zoology1 and indeed a part of the subject in its broader sense1 is the study of the geographical distribution of animal species and larger groups4 ,paleontology4--,the geological succession of organisms embraces a field where zoologist and geologist meet4 ,the wonderful progress made by ,american investigators is well described in the preceding chapters on ,historical ,geology and ,vertebrate ,paleontology4 ,biometry4 ,since ,darwin's theory of evolution postulated the origin of new species by means of natural selection1 it was obviously necessary in order to apply a critical test to determine the precise limits of a species4 ,it was1 therefore1 proposed to subject a given species to a strict examination by the application of statistical methods to determine the range of variation of its members and the extent to which the species intergrades with others4 ,other problems1 particularly those concerning heredity1 were treated in similar manner4 ,this branch of biological science was particularly developed by the ,english ,school1 led by ,sir ,francis ,galton1 followed by ,karl ,pearson and ,william ,bateson4 ,in ,america the methods of biometry have been utilized extensively by ,charles ,b4 ,davenport1 ,raymond ,pearl1 ,h4 ,s4 ,jennings and others in the solution of problems in genetics and evolution4 ,their work shows the great value of critical statistical analysis in the interpretation of biological data4 ,a thorough training in mathematics is now found to be hardly less important for the biologist than is a knowledge of physics and chemistry1 for the science of biometry has become one of the most important adjuncts to the study of genetics4 ,comparative ,anatomy and ,embryology4 ,comparative ,anatomy4--,upon the foundations laid down by ,cuvier a century ago the present elaborate structure of comparative anatomy of animals1 both vertebrate and invertebrate1 has been developed4 ,vast as is the present accumulation of facts and theories many important problems still await their solution4 ,jeffries ,wyman was long a leader in this field1 where many workers are now engaged4 ,embryology4--,the embryological studies1 so brilliantly begun by ,von ,baer early in the nineteenth century1 are still in progress4 ,they have now been extended to the groups more difficult of investigation and into the earliest stages of fertilization and implantation in the mammals4 ,artificial cultural methods have yielded important results4 ,louis and ,alexander ,agassiz1 ,mark1 ,minot1 ,brooks1 ,whitman1 ,conklin and ,e4 ,b4 ,wilson have taken prominent parts in this work4 ,in the early nineties embryological studies were directed to the arrangement of cells in the dividing egg1 and there was much discussion of 8cell lineage0 in development4 ,valuable as were these studies they threw comparatively little light on the general problems of evolution4 ,experimental ,embryology4--,a more fertile field1 developed at the same period and a little later1 was found in experimental embryology4 ,the discoveries made by ,driesch and others in shaking apart the cells of the dividing egg or by destroying one or more of these cells gave a new insight into the potency of cells for compensatory and regenerative processes4 ,these studies attracted many able investigators1 who made still further advance by subjecting the germ cells1 developing eggs1 embryos1 and developing organs to a great variety of artificial conditions4 ,artificial ,parthenogenesis4--,another question concerns the nature of the process of fertilization and the agencies which cause the fertilized egg to develop into an embryo4 ,in #ahii ,jacques ,loeb succeeded in causing development in unfertilized sea-urchin eggs by subjecting them to concentrated sea water for a period and then returning them to their normal environment4 ,to this promising field of experimental work came many of the foremost biologists both in ,america and ,europe4 ,it was soon found that the eggs of most groups of animals except the higher vertebrates could be made to develop into more or less perfect embryos and larval forms by treatment with a great variety of chemical substances1 by increased temperature1 by mechanical stimuli and by other means4 ,this artificial parthenogenesis1 as it is called1 has also been successful in plants 7,fucus71 and recently ,loeb has reared several frogs to sexual maturity by merely puncturing with a sharp needle the eggs from which they were derived4 ,loeb1 then1 maintains that 8the egg is the future embryo and animal2 and that the spermatozoon1 aside from its activating effect1 only transmits ,mendelian characters to the egg40#ahj ,further experimental analyses of the nature of the fertilization mechanism have recently been made by ,morgan1 ,conklin1 ,f4 ,r4 ,lillie1 and others4 ,germinal ,localization4--,the question as to whether the egg contains localized organ-forming substances has been studied experimentally particularly by means of the centrifuge4 ,the results indicate that neither of the older opposing theories of 8performation0 or 8epigenesis0 is applicable to all eggs1 but that in certain organisms the eggs possess a well marked differentiation while in others each part of the egg is essentially1 although probably not absolutely1 equipotential4 ,the ,germplasm ,cycle4--,since ,weismann's postulation of the independence of soma and germplasm in #ahhe many attempts have been made to trace the path of the hereditary substance from one generation to the next4 ,a recent book by ,hegner#aha summarizes the success attained in various groups of animals4 ,cytology4 ,another important field of investigation which has attracted many workers is that which pertains to the life of the cell--the science of cytology4 ,although the celltheory was established as early as #ahci1 little advance was made in this subject in ,america before #ahhj4 ,since that time1 however1 ,americans have been so successful in cytological discoveries that they are now among the world's leaders in this field4 ,these studies have been followed along both descriptive and experimental lines4 ,the most prominent of the early workers in this field are ,e4 ,l4 ,mark and ,e4 ,b4 ,wilson4 ,mark's description of the maturation1 fecundation1 and segmentation of the egg is the most accurate and complete of the early cytological studies4 ,wilson's discoveries concerning the details of fertilization and his 8,atlas of ,fertilization and ,karyokinesis10 published in #ahie1 have now become classic4 ,wilson1 too1 has published the only ,american text-book on cytology1#ahb and has more recently taken the lead in studies concerning the relation between the chromosomes and sex4 ,besides ,wilson1 ,montgomery1 ,mark1 ,mc,clung1 ,morgan1 ,miss ,stevens1 ,conklin and their associates and students have now furnished conclusive evidence that the sex of an organism is determined by1 or associated with1 the nuclear constitution of the fertilized egg4 ,this constitution is moreover shown to be dependent upon the chromosomes received from the germ cells4 ,this explanation is in strict accordance with the results of experimental breeding4 ,it is also quite in harmony with the ,mendelian law of inheritance1 and in fact forms one of the strongest supports for the view that all ,mendelian factors are resident in the chromosomes4 ,recent work has also discovered the mechanism which governs the complicated conditions of sex which occur in those animals which exhibit alternating sexual and parthenogenetic generations4 ,these remarkable processes are in all cases found to depend upon a definite distribution of the chromosomes4 ,other recent experimental work has shown that while the sex is thus normally determined in the fertilized egg1 it is in some animals not irrevocably fixed1 and the normal effect of the sex chromosomes may be inhibited by abnormal conditions in the developing embryo1 as is demonstrated by the recent work of ,lillie and others4 ,the cytological basis for ,mendelian inheritance has been very extensively studied by ,morgan and his pupils in connection with their work on inheritance in the common fruit fly ,drosophila4 ,the evidence supports ,weismann's earlier hypothesis that the chromosomes are the bearers of the heritable factors1 and that these are arranged in a series in the different chromosomes4 ,this theory is shown to be in such strict accord with both the cytological studies and the results of experimental breeding that ,morgan has ventured to indicate definite points in particular chromosomes as the loci of definite heritable factors1 or genes4 ,confirmation of this view is furnished by the behavior of the so-called sex-linked characters1 the genes for which are situated in the same chromosome as that which carries the sex factor4 ,many ingenious breeding experiments indicate further that all the hereditary characters in ,drosophila are borne in four great linkage groups corresponding with the four pairs of chromosomes which the cells of this fly possess4 ,comparative ,physiology4 ,none of the experimental fields has been of greater importance in zoological progress than that which concerns the functions of the various organs4 ,without this companion science morphology and comparative anatomy would have become unintelligible4 ,american investigators1 among whom ,g4 ,h4 ,parker stands prominent1 have taken a leading part in this field also4 ,neurology4--,the physiological analysis of the components of the nervous system1 both in vertebrates and invertebrates1 is another important branch of experimental biology4 ,the #bh volumes of the ,journal of ,comparative ,neurology attest the large influence that ,american investigators have had in the development of this science4 ,regeneration4--,experimental studies on the powers of regeneration in plants and animals have been made from the earliest times4 ,during the past few years1 however1 there has been made a concerted attempt to analyze the factors which determine the amount and rate of regeneration4 ,much progress has been made toward the postulation of definite laws applicable to the regenerative processes of the parts of each organism4 ,the critical analyses of ,morgan1 ,loeb and ,child have been particularly stimulating4 ,tissue ,culture4--,another line of experimental work which has been developed within the past few years by ,harrison1 ,carrell1 and others is the culture of body tissues in artificial media4 ,these experiments have included the cultivation in tubes or on glass slides of the various tissues of numerous species of animals4 ,they have yielded much information regarding the structure1 growth and multiplication of cells1 the formation of tissues1 and the healing of wounds4 ,transplantation and ,grafting4--,closely associated experiments consist in the transplantation of organs or other portions of the body to abnormal positions1 to the bodies of other animals of the same species or of other species4 ,in this way much has been learned about the potentiality of organs for self-differentiation1 for regulation1 for regeneration and for compensatory adaptations4 ,the experiments have shown1 further1 the independence of soma and germplasm and have revealed the nature of certain organs whose functions were previously obscure4 ,tropisms and ,instincts4--,another field of experimental biology concerns the analysis of behavior of organisms in response to various forms of stimuli4 ,these studies are being prosecuted on all groups of organisms1 including the larval stages of many animals1 and are yielding most remarkable results4 ,the success in this field of research is largely due to stimulating influence of ,jacques ,loeb1 ,parker1 ,jennings1 and their co-workers4 ,biological ,chemistry4--,still another experimental field which has developed into one of the most important of the biological sciences relates to the fundamental chemical and physical changes which underlie all organic phenomena4 ,a knowledge of both physiological and physical chemistry is to-day essential for all advanced biological work4 ,the peculiar nature of life itself1 of growth1 disease1 old-age1 degeneration1 death and dissolution are presumably only manifestations of chemical and physical laws4 ,the ultimate goal of all experimental biology1 therefore1 will be reached only when the basic physico-chemical properties of life are understood4 ,at that time only will the perennial controversy between vitalism and mechanism be ended4 ,economic ,zoology4 ,a moment's reflection will show that economic biology is the most essential of all sciences to the human welfare and progress4 ,for man's relation to his environment is such that the penalty for ignorance or neglect of the biological principles involved in the struggle for existence quickly overwhelms him with a horde of parasites or other enemies4 ,it is only by the intelligent application of biological knowledge that our food supplies1 our forests1 our domesticated animals and our bodies can be protected from the ever ravenous organisms which surround us4 ,the losses to food supplies and other products by insects alone amounts to #ajj millions of dollars a month in the ,united ,states4 ,and the parasites cause losses in sickness and premature deaths each year of many millions more4 ,then there are the destructive rodents and other animals which add largely to our burdens of support4 ,these enemies next to wars and fungi are the most destructive agencies on earth4 ,could they but be eliminated man's struggle against opposing forces would be in large measure overcome4 ,the results of recent work in economic zoology1 both in regard to the destruction of enemies and protection of useful mammals1 birds and fishes1 furnish a bright outlook for the future4 ,protozoology4--,partly as an experimental field for the solution of general biological problems and partly because of its practical applications the study of protozoa has now developed into a special science4 ,the results of the investigations of ,calkins1 ,woodruff1 ,jennings and others have greatly supplemented our understanding of the signification of such important biological phenomena as reproduction1 sexual differentiation1 conjugation1 tropisms1 and metabolism4 ,from an economic standpoint the protozoa have recently been shown to be of the greatest importance because of the human and animal diseases for which they are responsible4 ,parasitology4--,the animal parasites of man1 domesticated animals and plants include numerous species of protozoa1 worms1 and insects4 ,together with the bacteria and a few higher fungi they cause all communicable diseases4 ,when we consider that not only our health but also our entire food supply is dependent upon the elimination of these organisms we must admit that parasitology is the most important economically of all the sciences4 ,the reports of the investigations of ,stiles and his associates in the ,hygienic ,laboratory and of ,ransom and his staff in the ,bureau of ,animal ,industry are widely distributed by the federal government4 ,the systematic studies so ably begun by ,joseph ,leidy in the middle of the last century have been continued by ,ward1 ,linton1 ,pratt1 ,curtis and others on the parasites of many groups of animals4 ,economic ,entomology4--,another extremely important biological science1 the practical applications of which are second only to those of parasitology in importance1 is entomology4 ,in the last few years economic entomology has exceeded any of the other branches of biology in the number of its investigators4 ,the ,american ,association of ,economic ,entomologists has a membership of about five hundred4 ,the work of most of these is supported by appropriations from the ,state and federal governments1 and the results of their investigations are widely published4 ,it is now well known that some of the protozoon parasites are conveyed from man to man only through the bites of insects4 ,the local eradication of several of our most fatal diseases has recently been brought about by the application of measures to destroy such insects4 ,this is the greatest triumph of economic zoology4 ,economic ,ichthyology4--,the ,u4 ,s4 ,fish ,commission has for many years been actively engaged in investigations on the food fishes1 including methods for increasing the food supply by suitable protection and artificial propagation4 ,the work includes also edible and otherwise useful mollusks and crustacea4 ,their marine and fresh-water laboratories have also been of great service to general biological science4 ,economic ,ornithology and ,mammalogy4--,in addition to the local bird clubs and the ,american ,ornithologists ,union for the study and preservation of bird and mammal life1 the ,bureau of ,biological ,survey has for some years conducted investigations on the economic importance of the various species4 ,the publications of this ,bureau are of great value both in determining the economic status of our birds and mammals1 and also in recommending means for the protection of the beneficial species and the destruction of the injurious4 ,several of the ,states issue similar publications4 ,genetics4 ,one of the most interesting chapters in biology relates to the development of the modern science of heredity1 or genetics4 ,previous to the year #aijj1 when the ,mendelian principle of inheritance was re-discovered1 the relative importance of heredity and of environment in the development of an organism was little understood4 ,it is true that ,weismann had insisted on the independence of soma and germplasm some years earlier 7#ahhc71 but the body of the individual was still generally considered the key to its inheritance4 ,the recognition of the general application of ,mendel's discovery gave a great impetus to experimental breeding both in plants and animals4 ,while heretofore it had been necessary to depend upon the somatic characters as evidence of the hereditary constitution of an individual1 it now became possible1 knowing the hereditary constitution of the parents of any pair of individuals1 to predict with almost mathematical certainty the characters of their possible offspring4 ,in general1 the laws of possible chance combinations of any group of characters determine the probability of any particular offspring possessing one or many of those characters4 ,the physical basis for such ,mendelian inheritance is evidently the chance combinations of chromosomes which result from the processes of maturation and union of the germ cells4 ,certain limitations to the law are met with because the relatively small number of chromosomes involves linkage of genes1 because of the occasional interchange of groups of genes between homologous chromosomes1 and because the relative activity or potency of any particular gene may differ in different races1 and1 finally1 because the normal activity of any given gene may be modified or inhibited by the action of other genes4 ,it is by no means certain1 however1 that all inheritance is ,mendelian1 for there still remains much evidence that the hereditary basis of certain characters may be resident in the cytoplasm1 rather than in the chromosomes4 ,a recent book by ,morgan1 ,sturtevant1 ,mller and ,bridges 7#aiae71 entitled 8the mechanism of ,mendelian heredity0 gives the cytological explanation of ,mendelian inheritance4 ,americans have from the first taken a leading part in this field of research and have been quick to recognize its practical applications to the improvement of breeds in both animals and plants4 ,this prominent position is largely due to the experimental work of ,castle1 ,davenport1 ,morgan1 ,jennings1 ,pearl1 and their co-workers on animals and that of ,east1 ,emerson1 ,davis1 ,hayes and ,shull on plants4 ,the geneticist now realizes that the appearance of the body 7phenotype7 gives but little clue to the inheritance 7genotype74 ,that two white flowers produce only purple offspring1 or two white fowls only deeply colored chickens1 or that a pair of guinea pigs1 one of which is black and the other white1 have only gray agouti offspring1 while other apparently similar white flowers or white animals produce offspring like themselves1 is now readily comprehensible and mathematically predictable4 ,the most important application of our newly acquired knowledge of inheritance is in the improvement of the human race4 ,the wonderful opportunity in this direction must be apparent to all4 ,the welfare of humanity depends upon the immediate adoption of eugenic principles4 ,the ,eugenics ,record ,office has secured many of the essential data4 ,with the destruction of the world's best germ plasm at a rate never equalled before1 the outlook for the future race would be appalling were it not for the hope that with the advent of a righteous peace will come a realization of the necessity of applying these new biological discoveries to improving the races of men4 ,that the discoveries have been made too late in the world's history to be of such use to humanity must not be thought possible4 ,evolution4 ,previous to the publication of ,darwin's 8,origin of ,species0 in #ahei1 ,american zoologists were generally inclined toward special creation1 in spite of the evidences for evolution which had been presented by ,erasmus ,darwin1 ,buffon1 ,lamarck1 and ,geoffroy ,st4-,hilaire4 ,this attitude of mind continued for some years after the publication of the natural selection theory of ,darwin and ,wallace4 ,this was in part due to the powerful influence of ,louis ,agassiz and others who bitterly opposed the ,darwinian theory4 ,the influence of ,asa ,gray in gaining a general acceptance for this theory is explained in the following chapter4 ,a modified ,lamarckian doctrine was widely accepted in the last quarter of the century1 due largely to the influence of ,cope1 ,hyatt and ,packard4 ,the inheritance of 8acquired characters0 demanded by this theory seems incompatible with the discoveries of recent times1 so that 8to-day the theory has few followers amongst trained investigators1 but it still has a popular vogue that is wide-spread and vociferous40#ahc ,the origin of new varieties and species by accidental and fortuitous modifications 7mutations7 of the germplasm is now the most widely accepted theory of evolution4 ,some of the most important discoveries regarding the origin of new forms have been recently made by ,morgan and his pupils4 ,from a stock of the common fruit fly 7,drosophila ampelophila7 more than #abe new types have arisen within six years4 ,each of these types breeds true4 8,each has arisen independently and suddenly4 ,every part of the body has been affected by one or another of these mutations40 ,to arrange these mutations arbitrarily into graded series would give the impression of an evolutionary series1 but this is directly contrary to the known facts concerning their origin1 for each mutation 8originated independently from the wild type40 8,evolution has taken place by the incorporation into the race of those mutations that are beneficial to the life and reproduction of the individual40 ,this evolutionary process is usually accompanied by the elimination of those forms which have remained stable or which have developed adverse mutations4 ,a question that is being vigorously debated at this time concerns the possible effects of selection on the hereditary factors4 ,are the genes fixed both qualitatively and quantitatively or does a given gene vary in potency under different conditions and in different individuals8 ,in the former case selection can only separate the existing genes into separate pure strains4 ,but if the gene be quantitatively variable1 then selection will result in the establishment of new types4 ,castle has long stoutly maintained the effect of such selection1 and his forces have recently been augmented by ,jennings4 ,the experimental work now in process will doubtless yield a decisive answer4 ,conclusion4 ,a comparison of the simple descriptive natural history of a century ago with the foregoing manifold developments of modern biology will indicate the wonderful progress which has occurred during this period4 ,the path has led from the crude methods of the almost unaided eye and hand to the applications of the most delicate experimental apparatus4 ,for the marvelous success which zoology has attained has been possible only by the skillful use of scalpel1 microscope1 microtome and other mechanical devices and by the refined methods of the chemist and physicist4 ,the central truth to which all these discoveries consistently point is the unity and harmony of all biological phenomena1 and indeed of all nature4 ,no longer does the zoologist find any demarcated line separating his field of research from that of the botanist or the chemist or even of the physicist1 for all the natural sciences obviously deal with closely associated phenomena4 ,the aim of the future will be both to complete fields of study already marked out and to derive a comprehensive explanation of the general principles involved4 ,notes4 ,footnote #agb3 ,proc4 ,biol4 ,soc4 ,washington1 #c1 #ce1 #ahhf4 ,footnote #agc3 ,ibid41 #d1 #i1 #ahhh4 ,both of these papers are reprinted in ,ann4 ,rept4 ,smithsonian ,inst41 #ahig1 ,u4 ,s4 ,nat4 ,mus41 ,pt4 #b1 pp4 #ceg-dff1 #aija4 ,footnote #agd3 ,louis ,agassiz3 his ,life and ,correspondence1 by ,elizabeth ,carey ,agassiz1 p4 #ade1 #ahhe4 ,footnote #age3 ,list of ,north ,american ,land ,mammals in the ,united ,states ,national ,museum1 #aiaa4 ,bull4 #gi1 ,u4 ,s4 ,nat4 ,mus41 #aiab4 ,footnote #agf3 ,birds of ,north and ,middle ,america1 ,bull4 #ej1 parts ,i-,,vii1 ,u4 ,s4 ,nat4 ,mus41 #aija-aiaf4 ,footnote #agg3 ,report ,u4 ,s4 ,nat4 ,mus4 for #ahih1 pp4 #aec-abgj1 #aijj4 ,footnote #agh3 ,bull4 #cd1 ,u4 ,s4 ,nat4 ,mus41 #ahhi4 ,footnote #agi3 ,bull4 #dg1 parts ,i-,,iv1 ,u4 ,s4 ,nat4 ,mus41 #ahif-aijj4 ,footnote #ahj3 ,j4 ,loeb1 ,the ,organism as a ,whole1 p4 #abf1 #aiaf4 ,footnote #aha3 ,the ,germ-cell ,cycle in ,animals1 #aiad4 ,footnote #ahb3 ,the ,cell in ,development and ,inheritance1 #ahif2 second edition1 #aijj4 ,footnote #ahc3 ,morgan1 ,t4 ,h4 ,a critique of the theory of evolution1 p4 #cb1 #aiaf4 ,,xiii ,,the ,,development ,,of ,,botany ,,since #ahah ,by ,,george ,l4 ,,goodale 8,our ,botany1 it is true1 has been extensively and successfully investigated1 but this field is still rich1 and rewards every new research with some interesting discovery40 ,such are the words with which the sagacious and far-sighted founder of the ,american ,journal of ,science and ,arts1 in his general introduction to the first volume1 alludes to the study of plants4 ,it is plain that the editor1 embarking on this new enterprise1 appreciated the attractions of this inviting field and sympathetically recognized the good work which was being done in it4 ,it is not surprising1 therefore1 to find that he welcomed to the pages of his initial number contributions to botany4 ,early ,botanical ,works4--,the collections of dried and living ,north ,american plants1 which had been carried from time to time to botanists in ,europe1 had been eagerly studied1 and the results had been published in accessible treatises4 ,besides these general treatises1 there had been issued certain works1 wholly devoted to the ,american ,flora4 ,among these latter may be mentioned ,pursh's 8,flora0 7#ahad7 and ,nuttall's 8,genera0 7#ahah74 ,there were also a few works which were rather popular in their character1 such as ,amos ,eaton's 8,manual of ,botany for ,north ,america0 7#ahag71 and ,bigelow's 8,collection of the ,plants of ,boston and environs0 7#ahad74 ,these handbooks were convenient1 and possessed the charm of not being exhaustive2 consequently a botanist1 whether professional or amateur1 was stimulated to feel that he had a good chance of enriching the list of species and adding to the next edition4 ,the ,early ,years of ,botany in the ,journal4 ,at that time1 the botanists had no journal in this country devoted to their science4 ,here and there they found opportunity for publishing their discoveries in some medical periodical or in a local newspaper4 ,hence ,american botanists availed themselves of the welcome extended by ,silliman to botanical contributors to place their results on record in a magazine devoted to science in its wide sense4 ,specialization and subdivision of science had not then begun to dissociate allied subjects1 and1 consequently1 botanists felt that they would be at home in this journal conducted by a chemist4 ,botanists responded promptly to this invitation with interesting contributions4 ,it is well to remember that the appliances at the command of naturalists at the date when the ,journal began its service1 were imperfect and inadequate4 ,the botanist did not possess a convenient achromatic microscope1 and he was not in possession of the chemical aids now deemed necessary in even the simplest research4 ,hence1 attention was given almost wholly to such matters as the forms of plants and the more obvious phenomena of plant-life4 ,in view of the poverty of instrumental aids in research1 the results attained must be regarded as surprising4 ,in the very first volume of the ,journal1 bearing the date of #ahah1 there are descriptions of four new genera and of four new species of plants2 certainly a large share to give to systematic botany4 ,besides these articles1 there are some instructive notes concerning a few plants1 which up to that time had been imperfectly understood4 ,there are four ,floral ,calendars which give details in regard to the blossoming and the fruiting of plants in limited districts1 a botanical subject of some importance but likely to become tedious in the long run4 ,just here1 the skill of the editor in limiting undesirable contributions is shown by his tactful remark designed to soothe the feelings of a prolix writer whose too long list of plants in a floral calendar he had editorially cut down to reasonable limits4 ,the editor remarks1 8such extended observations are desirable1 but it may not always be convenient to insert very voluminous details of daily floral occurrence40 ,it is convenient to consider by themselves some of the botanical contributions published in the first series of volumes of the ,journal during a period of twenty years1 the period before ,asa ,gray became actively and constantly associated with the ,journal4 ,in systematic and geographical botany one finds communications from ,douglass and ,torrey 7#d1 #ef1 #ahbb7 on the plants of what was then the ,northwest2 ,lewis ,c4 ,beck 7#aj1 #beg1 #ahbf2 #aa1 #afg1 #ahbf2 #ad1 #aab1 #ahbh7 contributed valuable papers on the botany of ,illinois and ,missouri2 there is a literal translation by ,dr4 ,ruschenberger 7#ai1 #fc1 #bii1 #ahca2 #bj1 #bdh1 #ahca2 #bc1 #gh1 #bej1 #ahcc7 of a very long list of the plants of ,chili2 ,wolle and ,huebener 7#cg1 #caj1 #ahci7 gave an annotated catalogue of botanical specimens collected in ,pennsylvania2 ,tuckerman 7#de1 #bg1 #ahdc7 presented communications in regard to numerous species which he had examined critically2 ,darlington 7#da1 #cfe1 #ahda7 published his lecture on grasses2 ,asa ,gray 7#dj1 #a1 #ahda7 gave an instructive account of ,european herbaria visited by him1 and he contributed also a charming account 7#db1 #a1 #ahdb7 of a botanical journey to the mountains of ,north ,carolina4 ,the most extensive series of botanical communication at this time was the ,caricography by ,professor ,dewey of ,williams ,college1 presented in many numbers of the ,journal2 the first of these in #g1 pp4 #bfd-bgh1 #ahbd4 ,there were also descriptions of certain new genera1 and species1 and critical studies in synonyms4 ,cryptogamic botany is represented in the first series of volumes of the ,journal by ,l4 ,c4 ,beck's 7#ae1 #bhg1 #ahbi7 study of ferns and mosses1 by ,bailey's 7#ce1 #aac1 #ahci7 histology of the vascular system of ferns1 by ,fries' ,systema mycologicum 7#ab1 #bce1 #ahbi71 and by ,de ,schweinitz 7#i1 #cig1 #ahbe7 and ,halsey1 who had in hand a cryptogamic manual4 ,there are two important papers by ,alexander ,braun1 translated by ,dr4 ,george ,engelmann1 one on the ,equisetace of ,north ,america 7#df1 #ha1 #ahdd7 and the other on the ,charace 7#df1 #ib1 #ahdd74 ,vegetable paleontology had begun to attract attention in many places in this country1 and therefore the translated contributions by ,brongniart on fossil plants were given space in the ,journal4 ,plant-physiology received a good share of attention either in short notices or in longer articles4 ,such titles appear as1 the respiration of plants1 the circulation of sap1 the excrementitious matter thrown off by plants1 the effects of certain gases and poisons on plants1 and the relations of plants to different colored light4 ,one of the most important of the notes is that in which is described the discovery by ,robert ,brown 7#ai1 #cic1 #ahca7 of the constant movement of minute particles suspended in a liquid1 first detected by him in the fovilla of pollen grains1 and now known as the ,brownian 7or ,brunonian7 movement4 ,the heading under which this note appears is of interest1 8,the motion of living particles in all kinds of matter40 ,one side of botany touches agriculture and economics4 ,that side was represented even in the first volume of the ,journal by a study of 8the comparative quantity of nutritious matter which may be obtained from an acre of land when cultivated with potatoes or wheat40 ,succeeding volumes in this series likewise present phases which are of special interest regarded from the point of view of economics2 for example1 those which treat of rotation of crops and of enriching the soil4 ,probably the economic paper which may be regarded as the most important1 in fact epoch-making1 is the full account of the invention by ,appert of a method for preserving food indefinitely 7#ac1 #afc1 #ahbh74 ,we all know that ,appert's process has revolutionized the preservation of foods1 and in its modern modification underlies the vast industry of canned fruits1 vegetables and so on4 ,there are suggestions1 also1 as to the utilization of new foods1 or of old foods in a new way1 which resemble the suggestions made in these days of food conservation4 ,for example1 it is shown that flour can be made from leguminous seeds by steaming and subsequent drying1 and pulverizing4 ,there are excellent hints as to the best ways of preparing and using potatoes1 and also for preserving them underground1 where they will remain good for a year or two4 ,it is shown that potato flour can be made into excellent bread4 ,another method of making bread1 namely from wood1 is described1 but it does not seem quite so practicable4 ,there are interesting notes on the sugar-beet as a source of sugar1 and here appears one of the earliest accounts of the ,assam tea-plant1 which was destined to revolutionize the tea industry throughout the world4 ,cordage and textile fibers of bark and of wood should be utilized in the manufacture of paper4 ,in fact one comes upon many such surprises in economic botany as the earlier volumes of the ,journal are carefully examined4 ,early numbers of the ,journal present with sufficient fullness accounts of the remarkable discovery by ,daguerre and others of a process for taking pictures by light1 on a silver plate or upon paper 7#cg1 #cgd1 #ahci2 #ch1 #ig1 #ahdj1 etc474 ,before many years passed1 the ,journal had occasion to show that these novel photographic delineations could be made useful in the investigation of problems in botany4 ,in the pages of the ,journal it would be easily possible to trace the development of this art in its relations to natural history4 ,silliman possessed great sagacity in selecting for his enterprise all the novelties which promised to be of service in the advancement of science4 ,in #ahbe 7#i1 #bfc7 the ,journal republished from the ,edinburgh ,journal of ,science an essay by ,dr4 7afterwards ,sir7 ,william ,jackson ,hooker1 on ,american ,botany4 ,in this essay the author states that 8the various scientific ,journals0 which 8are published in ,america1 contain many memoirs upon the indigenous plants4 ,among the first of these in point of value1 and we think also the first with regard to time1 we must name ,silliman's ,journal of ,science40 ,the author enumerates some of the contributors to the ,journal and the titles of their papers4 ,it has been a useful practice of the ,journal1 almost from the first1 to transfer to its pages memoirs which would otherwise be likely to escape the notice of the majority of ,american botanists4 ,the book notices and the longer book reviews covered so wide a field that they placed the readers of the ,journal in touch with nearly all of the current botanical literature both here and abroad4 ,these critical notices did much towards the symmetrical development of botany in the ,united ,states4 ,and as we shall now see1 the ,journal notices and reviews in the hands of ,asa ,gray continued to be one of the most important factors in the advancement of ,american botany4 ,asa ,gray and the ,journal4 ,in #ahcd there appears in the ,journal 7#be1 #cdf7 a 8,sketch of the ,mineralogy of a portion of ,jefferson and ,st4 ,lawrence ,counties1 ,new ,york1 by ,j4 ,b4 ,crawe of ,watertown and ,a4 ,gray of ,utica1 ,new ,york40 ,this appears to be the first mention in the ,journal of the name of ,dr4 ,asa ,gray1 who1 shortly after that date1 became thoroughly identified with its botanical interests4 ,in the early part of his career both before and immediately after graduating in medicine1 ,gray gave much attention to the different branches of natural history in its wide sense4 ,he not only studied but taught 8chemistry1 geology1 mineralogy1 and botany10 the latter branch being the one to which he devoted most of his attention4 ,among his early guides in the pursuit of botany may be mentioned ,dr4 ,hadley1 8who had learned some botany from ,dr4 ,ives of ,new ,haven10 and ,dr4 ,lewis ,c4 ,beck of ,albany1 author of ,botany of the ,united ,states ,north of ,virginia4 ,at that period he made the acquaintance of ,dr4 ,john ,torrey of ,new ,york1 with whom he later became associated in most important descriptive work4 ,during the years between his graduation in medicine and #ahdb1 the year when he came to ,harvard ,college1 his activities were diverse and intense2 so that his preparation for his distinguished career was very broad and thorough4 ,his first visit to ,europe1 in #ahch1 brought him into personal relations with a large number of the botanists of ,great ,britain and the ,continent4 ,this extensive acquaintance1 added to his broad training1 enabled him even from the outset to exert a profound influence upon the progress of his favorite science4 ,he made the ,journal tributary to this development4 ,his name first appears as associate editor in #ahec1 but there are articles in the ,journal from his pen which bear an earlier date4 ,the first of these early botanical papers is the following3 8,a ,translation of a memoir entitled #8,beitrge zur ,lehre von der ,befruchtung der ,pflanzen1' 7contributions to the doctrine of the impregnation of plants1 by ,a4 ,j4 ,c4 ,corda37 with prefatory remarks on the progress of discovery relative to vegetable fecundation2 by ,asa ,gray1 ,m4 ,d40 7#ca1 #cjh1 #ahcg74 ,dr4 ,gray says that he made the translation from the ,german for his own private use1 but thinking that it might be interesting to the ,lyceum1 he brought it before the ,society1 with 8a cursory account of the progress of discovery respecting the fecundation of flowering plants1 for the purpose of rendering the memoir more generally intelligible to those who are not particularly conversant with the present state of botanical science40 ,the translation occupies six pages of the ,journal1 while the prefatory remarks fill nine pages4 ,the prefatory remarks constitute an exhaustive essay on the subject1 embodied in attractive and perfectly clear language4 ,the translator shows complete familiarity with the matter in hand and gives an adequate account of all the work done on the subject up to the date of ,m4 ,corda's paper4 ,a second important paper by him near this period is his review of 8,a ,natural ,system of ,botany3 or a systematic view of the ,organization1 ,natural ,affinities1 and ,geographical ,distribution of the whole ,vegetable ,kingdom2 together with the use of the more important species in ,medicine1 the ,arts1 and rural and domestic economy1 by ,john ,lindley4 ,second edition1 with numerous additions and corrections1 and a complete list of genera and their synonyms4 ,london3 #ahcf0 7#cb1 #bib1 #ahcg74 ,a very brief notice of this work in the first part of the volume for #ahcg closes with the words1 8,a more extended notice of the work may be expected in the ensuing number of the ,journal40 ,the extended notice proved to be a critical study of the work1 signed by the initials ,a4 ,g4 which later became so familiar to readers of the ,journal4 ,citation of a few of its sentences will indicate the strong and quiet manner in which ,dr4 ,gray1 even at the outset1 wrote his notices of books4 ,in speaking of the second edition of ,professor ,lindley's work1 he says3 ,illustration3 ,sincerely yours ,asa ,gray 8,it is not necessary to state that a treatise of this kind was greatly needed1 or to allude to the peculiar qualifications of the learned and industrious author for the accomplishment of the task1 or the high estimation in which the work is held in ,europe4 ,but we may properly offer our testimony respecting the great and favorable influence which it has exerted upon the progress of botanical science in the ,united ,states4 ,great as the merits of the work undoubtedly are1 we must nevertheless be excused from adopting the terms of extravagant and sometimes equivocal eulogy employed by a popular author1 who gravely informs his readers that no book1 since printed ,bibles were first sold in ,paris by ,dr4 ,faustus1 ever excited so much surprise and wonder as did ,dr4 ,torrey's edition of ,lindley's ,introduction to the ,natural ,system of ,botany4 ,now we can hardly believe that either the author or the ,american editor of the work referred to was ever in danger1 as was honest ,dr4 ,faustus1 of being burned for witchcraft1 neither do we find anything in its pages calculated to produce such astonishing effects1 except1 perhaps1 upon the minds of those botanists1 if such they may be called1 who had never dreamed of any important changes in the science since the appearance of good ,dr4 ,turton's translation of the ,species ,plantarum1 and who speak of ,jussieu as a writer who has greatly improved the natural orders of ,linnus40 ,in the ,journal for #ahdj there is a large group of unsigned book reviews under the heading1 8,brief notices of recent ,botanical works1 especially those most interesting to the student of ,north ,american ,botany40 ,the first of these short reviews deals with the second section of ,part ,,vii of ,de ,candolle's 8,prodromus40 ,in #ahdg the consideration of the 8,prodromus0 is resumed by the same author and the initials of ,a4 ,g4 are appended4 ,this indicates that ,dr4 ,gray was probably the writer of some of the unsigned book reviews which had appeared in the ,journal between #ahcg and #ahdj4 ,doubtless ,silliman availed himself of the assistance of his associates1 ,eli ,ives and others1 in ,new ,haven1 in the examination of current botanical literature1 and it is extremely probable that he early secured help from young ,dr4 ,gray1 who had shown himself to be a keen critic as well as a pleasing writer4 ,the notices of botanical works from #ahdj bear marks of having been from the same hand4 ,they cover an extremely wide range of subjects4 ,while they are good-tempered they are critical1 and they had much to do with the development of botany1 in this country1 along safe lines4 ,gray as ,editor4--,gray's name as associate editor of the ,journal appears in #ahec4 ,he had been a welcome contributor1 as we have seen1 for many years4 ,his influence upon the progress of botany in the ,united ,states was largely due to his connection with the ,journal4 ,his reviews extended over a very wide range1 and supplemented to a remarkable degree his other educational work4 ,it must be permitted to allude here to his sagacity as a writer of educational treatises4 ,in his first elementary text-book1 published in #ahcf1 he expressed wholly original views in regard to certain phases of structure and function in plants1 which became generally adopted at a later date4 ,his ,manual of ,botany was constructed1 and subsequent editions were kept1 on a plan which made no appeal to those who wanted to work on lines of least resistance2 in fact he had no patience with those who desired merely to ascertain the name of a plant4 ,in the ,journal he emphasizes the desirability of learning all the affinities of the plant under consideration4 ,at a later period1 when entirely new chapters had been opened in the life of plants1 he sought by his contributions in the ,journal to interest students in this wider outlook4 ,professor ,c4 ,s4 ,sargent has selected with good judgment some of the more important scientific papers by ,professor ,gray and has republished them in a convenient form4#ahd ,many of these papers were contributed to the ,journal in the form of reviews4 ,these reviews touch nearly every branch of the science of botany4 ,as ,sargent justly says1 8,many of the reviews are filled with original and suggestive observations1 and taken together1 furnish the best account of the development of botanical literature during the last fifty years that has yet been written40 ,in these longer reviews in the ,journal1 ,gray was wont to take a book under review as affording an opportunity to illustrate some important subject1 and many of the reviews are crowded with his expositions4 ,for example1 in his examination of von,mohl's 8,vegetable ,cell0 7#ae1 #dea1 #ahec7 he takes up the whole subject of microscopic structure1 so far as it was then understood1 and he points out the probable errors of some of ,mohl's contemporaries1 showing what and how great were ,mohl's own contributions to histology4 ,such a review is a landmark in the science4 ,the physiology of the cell and the nutrition of the plant were favorite topics with ,professor ,gray1 and he brought much of his knowledge in regard to them into such a review as that of ,boussingault 7#be1 #abj1 #aheh7 on the 8,influence of nitrates on the production of vegetable matter40 ,as a systematic botanist1 ,gray was naturally much interested in the vexed question of nomenclature of plants4 ,one of his most important communications to the ,journal is his review1 in the volume for #ahhc 7#bf1 #dag71 of ,de,candolle's work on the subject4 ,he deals with this strictly technical matter much as he did in a contribution to the ,journal which he made in #ahfh 7#df1 #fc74 ,in both of these papers he states with clearness the general features of the code of nomenclature4 ,he says explicitly that the code does not make1 but rather declares1 the common law of botanists4 ,the treatment of the subject at his hands would rightly impress a general reader as showing a strong desire to have common sense applied to doubtful cases1 instead of insisting on inflexible rules4 ,for this reason1 his rule of practice was not always acceptable to those who were anxious to secure conformity to arbitrary rules at whatever cost4 ,as he said in a paper published in the ,journal in #ahdg 7#c1 #cjb71 8,the difficulty of a reform increases with its necessity4 ,it is much easier to state the evils than to relieve them2 and the well-meant endeavors that have recently been made to this end1 are1 some of them1 likely1 if adopted1 to make confusion worse confounded40 ,this feeling led him to be very conservative in the matter of reform in nomenclature4 ,this subject of botanical nomenclature illustrates a method frequently employed by ,professor ,gray to elucidate a difficult matter4 ,he would find in the treatise under review a text1 or texts1 on which he would build a treatise of his own1 and in this way he made clear his own views relative to most of the important phases of botany4 ,when he faced controverted matters1 his attitude still remained judicial4 ,while he was tolerant of opinions which clashed with his own1 he was always severe upon charlatanism and impatient of inaccuracy4 ,the pages of the ,journal contain many severe criticisms at his hands1 but an unprejudiced person would say that the severity is merited4 ,sometimes1 however1 instead of reviewing a book or an address1 he would follow the custom inaugurated early in the history of the ,journal1 of making copious extracts1 and thus give to its readers an opportunity of examining materials which otherwise might not fall in their way4 ,gray's contributions to the ,journal comprise more than one thousand titles1 without counting the memorial notices and the shorter obituary notes4 ,in these notices he sums up in a few well-chosen words the contributions made to botany by his contemporaries4 ,even in the few instances in which he felt obliged to note with disapproval some of the work1 he expressed himself with personal friendliness4 ,the necrology1 as it appeared from month to month1 was a labor of love4 ,all of the longer memorial notices are what it is the fashion now-a-days to call appreciations1 and these are so happily phrased that it would seem as if the writer in many a case asked himself1 8,would my friend1 about whom ,i am now writing1 make any change in this sketch80 ,gray on ,darwinism4--,in ,october1 #ahei1 ,darwin's epoch-making work1 8,the ,origin of ,species10 was published4 ,an early copy was sent to the editor of the ,journal1 ,professor ,james ,d4 ,dana4 ,this arrived in ,new ,haven on ,december #ba1 but it was preceded by a personal letter which is of so much interest that it is here transcribed in full4 ,it should be added that ,dana was at this time in ,europe where he was spending a year in the search for health after a serious nervous breakdown4 ,in his absence the book was noticed by ,gray as stated below4 ,the letter is1 as follows3 ,down1 ,bromley1 ,kent4 ,nov4 #aath1 #ahei4 ,my dear ,sir1 ,i have sent you a copy of my ,book 7as yet only an abstract7 on the ,origin of ,species4 ,i know too well that the conclusion1 at which ,i have arrived1 will horrify you1 but you will1 ,i believe and hope1 give me credit for at least an honest search after the truth4 ,i hope that you will read my ,book1 straight through2 otherwise from the great condensation it will be unintelligible4 ,do not1 ,i pray1 think me so presumptuous as to hope to convert you2 but if you can spare time to read it with care1 and will then do what is far more important1 keep the subject under my point of view for some little time occasionally before your mind1 ,i have hopes that you will agree that more can be said in favour of the mutability of species1 than is at first apparent4 ,it took me many long years before ,i wholly gave up the common view of the separate creation of each species4 ,believe me1 with sincere respect and with cordial thanks for the many acts of scientific kindness which ,i have received from you1 ,my dear ,sir1 ,yours very sincerely1 ,,charles ,,darwin4 ,in ,march1 #ahfj 7#bi1 #aec71 ,gray published in the ,journal an elaborate and cautious review of ,darwin's work4 ,he alluded to the absence of the chief editor of the ,journal in the following words3 8,the duty of reviewing this volume in the ,american ,journal of ,science would naturally devolve upon the principal editor whose wide observation and profound knowledge of various departments of natural history1 as well as of geology1 particularly qualify him for the task4 ,but he has been obliged to lay aside his pen to seek in distant lands the entire repose from scientific labor so essential to the restoration of his health1 a consummation devoutly to be wished and confidently to be expected4 ,interested as ,mr4 ,dana would be in this volume1 he could not be expected to accept its doctrine4 ,views so idealistic as those upon which his #8,thoughts upon ,species' are grounded1 will not harmonize readily with a doctrine so thoroughly naturalistic as that of ,mr4 ,darwin4444 ,between the doctrines of this volume and those of the great naturalist whose name adorns the title page of this ,journal ,mr4 ,agassiz the widest divergence appears40 ,gray then proceeds to contrast the two views of ,darwin and ,agassiz1 8for this contrast brings out most prominently and sets in strongest light and shade the main features of the theory of the origination of species by means of ,natural ,selection40 ,he then states both sides with great fairness1 and proceeds3 8,who shall decide between such extreme views so ably maintained on either hand1 and say how much truth there may be in each4 ,the present reviewer has not the presumption to undertake such a task4 ,having no prepossession in favor of naturalistic theories1 but struck with the eminent ability of ,mr4 ,darwin's work1 and charmed with its fairness1 our humbler duty will be performed if1 laying aside prejudice as much as we can1 we shall succeed in giving a fair account of its method and argument1 offering by the way a few suggestions such as might occur to any naturalist of an inquiring mind4 ,an editorial character for this article must in justice be disclaimed4 ,the plural pronoun is employed not to give editorial weight1 but to avoid even the appearance of egotism and also the circumlocution which attends a rigorous adherence to the impersonal style40 ,in this review he moves slowly and thoughtfully1 but not timidly1 over the new paths4 ,there is no clear indication in the review that he has yet made up his mind as to the validity of ,darwin's hypothesis4 ,but1 in a second article appearing in the ,journal for ,september of the same year 7#cj1 #bbf71 under the title 8,discussion between two readers of ,darwin's treatise on the origin of species upon its natural theology0 ,gray plainly begins to incline to take a very favorable view of the ,darwinian theory1 and makes use of the following ingenious illustration to show that it is not inconsistent with theistic design4 ,a few paragraphs here quoted show the felicity of his style in a controverted matter3 8,recall a woman of a past generation and show her a web of cloth2 ask her how it was made1 and she will say that the wool or cotton was carded1 spun1 and woven by hand4 ,when you tell her it was not made by manual labor1 that probably no hands have touched the materials throughout the process1 it is possible that she might at first regard your statement as tantamount to the assertion that the cloth was made without design4 ,if she did1 she would not credit your statement4 ,if you patiently explained to her the theory of carding-machines1 spinning-jennies1 and power-looms1 would her reception of your explanation weaken her conviction that the cloth was the result of design8 ,it is certain that she would believe in design as firmly as before1 and that this belief would be attended by a higher conception and reverent admiration of a wisdom1 skill1 and power greatly beyond anything she had previously conceived possible40 ,by this review ,gray disarmed hostility to such an extent that some persons who had been antagonistic to ,darwinism accepted it with only slight reservation4 ,it may be fairly claimed that the ,journal bore a leading part in influencing the views of naturalists in ,america in regard to the ,darwinian theory4 ,dr4 ,gray soon put the ,darwinian hypothesis to a severe test4 ,in the ,journal for #ahdj he had called attention to the remarkable similarity which exists between the flora of ,japan and a part of the temperate portion of ,north ,america4 ,the first notice of this subject by him occurs in a short review of ,dr4 ,zuccarini's 8,flora ,japonica10 a work based on material furnished by ,dr4 ,siebold1 who had long lived in ,japan4 ,in this review 7#ci1 #age1 #ahdj71 he enumerates certain plants common to the two regions1 and says1 8,it is interesting to remark how many of our characteristic genera are reproduced in ,japan1 not to speak of striking analogous forms40 ,in a subsequent paper 7#bh1 #ahg1 #ahei71 he recurs to this subject1 and1 after alluding to geological data furnished by ,j4 ,d4 ,dana1 he says3 8,i cannot resist the conclusion that the extant vegetable kingdom has a long and eventful history1 and that the explanation of apparent anomalies in the geographical distribution of species may be found in the various and prolonged climatic or other vicissitudes to which they have been subject in earlier times2 that the occurrence of certain species1 formerly supposed to be peculiar to ,north ,america1 in a remote or antipodal region1 affords in itself no presumption that they were originated there1 and that interchange of plants between eastern ,north ,america and eastern ,asia is explicable upon the most natural and generally received hypothesis 7or at least offers no greater difficulty than does the arctic flora1 the general homogeneousness of which round the world has always been thought compatible with local origin of the species7 and is perhaps not more extensive than might be expected under the circumstances4 ,that the interchange has mainly taken place in high northern latitudes1 and that the isothermal lines have in earlier times turned northward on our eastern and southward on our northwest coast1 as they do now1 are points which go far towards explaining why eastern ,north ,america1 rather than ,oregon and ,california1 has been mainly concerned in this interchange1 and why the temperate interchange1 even with ,europe1 has principally taken place through ,asia40 ,illustration3 ,from 8,life and ,letters of ,charles ,darwin0 by ,francis ,darwin4 ,this paper was communicated in #ahei1 on the eve of the publication of ,darwin's 8,origin of ,species40 ,at a later date he applied the ,darwinian theory to the possible solution of the problem1 and came to the conclusion that the two floras had a common origin in the ,arctic zone1 during the ,tertiary period1 or the ,cretaceous which preceded it1 and the descendants had made their way down different lines toward the south1 the species varying under different climatic conditions1 and thus exhibiting similarity but not absolute identity of form4 ,before the ,american ,association for the ,advancement of ,science1 in his ,presidential address1 in #ahgb1 he used the following language3 8,according to these views1 as regards plants at least1 the adaptation to successive times and changed conditions has been maintained1 not by absolute renewals1 but by gradual modifications4 ,i1 for one1 cannot doubt that the present existing species are the lineal successors of those that garnished the earth in the old time before them1 and that they were as well adapted to their surroundings then1 as those which flourish and bloom around us are to their conditions now4 ,order and exquisite adaptation did not wait for man's coming1 nor were they ever stereotyped4 ,organic ,nature--by which ,i mean the system and totality of living things1 and their adaptation to each other and to the world--with all its apparent and indeed real stability1 should be likened1 not to the ocean1 which varies only by tidal oscillations from a fixed level to which it is always returning1 but rather to a river1 so vast that we can neither discern its shores nor reach its sources1 whose onward flow is not less actual because too slow to be observed by the ephemer which hover over its surface1 or are borne upon its bosom40 ,gray's active interest in the ,journal continued until the very end of his life4 ,there were many critical notices from his pen in #ahhg4 ,his last contribution to its pages was the botanical necrology1 which appeared posthumously in volume #ce1 of the third series 7#ahhh74 ,his connection with the ,journal covered1 therefore1 a period of more than a half a century of its life4#ahe ,the changes that were wrought in botany by the application of ,darwinism were far reaching4 ,attempts were promptly made to reconstruct the system of botanical classification on the basis of descent4 ,the more successful of these endeavors met with welcome1 and now form the groundwork of arrangement of families1 genera1 and species1 in the ,herbaria in this country1 in the manuals of descriptive botany1 and in the text-books of higher grade4 ,this overturn did not take place until after ,gray's death1 although he foresaw that the revolution was impending4 ,one of the most obvious changes was that which gave a high degree of prominence in ,american school treatises to the study of the lower instead of the higher or flowering plants1 these latter being treated merely as members in a long series1 and with scant consideration4 ,but of late years1 there has been a renewed popular interest in the phnogamia1 leading to a more thorough investigation of local floras1 and also to the examination of the relations of plants to their surroundings4 ,the results of a large part of this technical work are published in strictly botanical periodicals and now-a-days seldom find a place in the pages of a general journal of science4 ,cryptogamic ,botany in the ,journal since #ahdf4 ,in glancing rapidly at the ,first ,series it has been seen that a fair share of attention was early paid by the ,journal to the flowerless plants4 ,so far as the means and methods of the time permitted1 the ferns1 mosses1 lichens1 and the larger alg and fungi of ,america were studied assiduously and important results were published1 chiefly on the side of systematic botany4 ,the ,second ,series comprises the years between #ahdf and #ahga4 ,in this series one finds that the range of cryptogamic botany is much widened4 ,besides interesting book notices relative to these plants1 there are a good many papers on the larger fungi1 on the alg1 and mosses4 ,here are contributions by ,curtis1 by ,ravenel1 by ,bailey1 and by ,sullivant4 ,the lichens are treated of in detail by ,tuckerman1 and there are some excellent translations by ,dr4 ,engelmann of papers by ,alexander ,braun4 ,some of the destructive fungi are considered1 as might well be the case in the period of the potato famine4 ,it is in these years that one first finds the name of ,daniel ,cady ,eaton1 who later had so much to do with developing an interest in the subject of ferns in this country4 ,he was a frequent contributor of critical notices4 ,cryptogamic ,botany1 as it is now understood1 is a comparatively modern branch of science4 ,the appliances and the methods for investigating the more obscure groups1 and especially for revealing the successive stages of their development1 were unsatisfactory until the latter half of the last century4 ,gray recognized this condition of affairs1 and appreciated the importance of the new methods and the better appliances4 ,therefore he viewed with satisfaction the pursuit of these studies abroad by one of his students and assistants1 ,william ,g4 ,farlow4 ,dr4 ,farlow carried to his studies under ,de,bary and others unusual powers of observation and great industry4 ,he speedily became an accomplished investigator in cryptogamic botany and enriched the science by notable discoveries1 one of which to-day bears his name in botanical literature4 ,on his return to the ,united ,states1 ,farlow entered at once upon a successful career as an inspiring teacher and a fruitful investigator4 ,he became a frequent contributor to the ,journal1 keeping its readers in touch with the more important additions to cryptogamic botany4 ,he had wisely chosen to deal with the whole field1 and consequently he has been able to preserve a better perspective than is kept by the extreme specialist4 ,the greater number of cryptogamic botanists in this country have been under ,professor ,farlow's instruction4 ,systematic and ,geographical ,botany of ,late ,years4 ,the usefulness of the ,journal in descriptive systematic botany of phanerogams is shown not only by its acceptance of the leading features of ,de,candolle's ,phytography1 where very exact methods are inculcated1 but by the very numerous contributions by ,sereno ,watson and others at the ,harvard ,university ,herbarium1 as well as from private systematists4 ,it is in the pages of the ,journal that one finds the record of much of the critical work of ,tuckerman and of ,engelmann1 in interesting ,phanerogamia4 ,of late years the ,journal has had the privilege1 of publishing a good deal of the careful work of ,theo ,holm1 in the difficult groups of ,cyperace1 and also his admirable studies in the morphology and the anatomy of certain interesting plants of higher orders4 ,attention was called1 in passing1 to ,gray's deep interest in geographical botany4 ,in this important branch1 besides his contributions1 one finds1 among many others1 such papers as ,le,conte's 8,flora of the ,coast ,islands of ,california in ,relation to ,recent ,changes of ,physical ,geography0 7#cd1 #deg1 #ahhg71 and ,sargent's 8,forests of ,central ,nevada0 7#ag1 #dag1 #ahgi74 ,examination reveals a surprising number of communications which bear indirectly upon this subject4 ,paleontological ,botany4 ,when the ,journal began its career1 the subject of fossil plants was very obscure4 ,brongniart's papers1 especially the ,journal translations1 enabled the students in ,america to undertake the investigation of such fossils and the results were to a considerable extent published in the ,journal4 ,since the subject belongs as much to geology as to botany1 it finds its appropriate home in the pages of the ,journal4 ,the recent papers on this topic show how great has been the advance in methods and results since the early days of the ,journal's century4 ,under the care of ,george ,e4 ,wieland1 the communications and the bibliographical notices of paleontological treatises show the progress which he and others are making in this attractive field4 ,economic ,botany1 ,plant ,physiology1 etc4 ,at the outset1 the ,journal1 as we have seen1 devoted much attention to certain phases of economic botany1 and1 even down to the present1 it has maintained its hold upon the subject4 ,the correspondence of ,jerome ,nickls from #ahec to #ahfg brought before its readers a vast number of valuable items which would not in any other way have been known to them4 ,and the ,journal dealt wisely with the scientific side of agriculture1 under the hands of ,s4 ,w4 ,johnson and ,j4 ,h4 ,gilbert1 and others1 placing it on its proper basis4 ,this work was supplemented by ,norton's remarkable work in the chemistry of certain plants1 the oat1 for example1 and certain plant-products4 ,in fact it might be possible to construct from the pages of the ,journal a fair synopsis of the important principles of agronomy4 ,physiology has been represented not only by the studies which had been inaugurated and stimulated by the ,darwinian theory1 such as the cross-fertilization and the close-fertilization of plants1 plant-movements1 and the like1 but there have been a good many special communications1 such as ,dandeno on toxicity1 ,plowman on electrical relations1 and ionization1 and ,w4 ,p4 ,wilson on respiration4 ,there are many broad philosophical questions which have found an appropriate home in the ,journal1 such as 8,the ,plant-individual in its relation to the species0 7,alexander ,braun1 #ai1 #big1 #ahee2 #bj1 #aha1 #ahee71 and 8,the analogy between the mode of reproduction in plants and the alternation of generations observed in some radiata0 7,j4 ,d4 ,dana1 #aj1 #cda1 #ahej74 ,akin to these are many of the reflections which one finds scattered throughout the pages of the ,journal1 frequently in minor book notices4 ,as might be expected1 some attention has been paid to the very special branch of botany which is strictly called medical4 ,for example1 early in its history1 the ,journal published a long treatise by ,dr4 ,william ,tully 7#b1 #de1 #ahbj71 on the ergot of rye4 ,this is considered from a structural as well as from a medical point of view and is decidedly ahead of the time in which it was written4 ,there are a few references to vegetable poisons1 and there is a fascinating account of the effect of the common white ash on the activities of the rattlesnake4 ,in short it may be said that the editor did much towards making the ,journal readable as well as strictly scientific4 ,the list of reviewers who have been permitted to use the pages of the ,journal for notices of botanical and allied books in recent years is pretty long4 ,one finds the initials of ,wesley ,r4 ,coe1 ,george ,p4 ,clinton1 ,arthur ,l4 ,dean1 ,alexander ,w4 ,evans1 ,william ,g4 ,farlow1 ,george ,l4 ,goodale1 ,arthur ,h4 ,graves1 ,herbert ,e4 ,gregory1 ,lafayette ,b4 ,mendel1 ,leo ,f4 ,rettger1 ,benjamin ,l4 ,robinson1 ,george ,r4 ,wieland1 and others4 ,at the present time1 in the biological sciences1 as in every department of thought1 there is great specialization1 and each specialty demands its own private organ of publication4 ,naturally this has led to a falling off in the botanical communications to the ,journal1 but it cannot be forgotten that the history of ,north ,american ,botany has been largely recorded in its pages4 ,notes4 ,footnote #ahd3 ,scientific ,papers of ,asa ,gray4 ,selected by ,charles ,sprague ,sargent4 ,two volumes1 ,boston1 #ahhi 7see notice in vol4 #ch1 #dai1 #ahhi74 ,footnote #ahe3 ,a notice of ,gray's life and works is given by his life-long friend1 ,j4 ,d4 ,dana1 in the ,journal in #ahhh 7#ce1 #aha-bjc74 ---------------------------------------- -------------------------------- ,,transcriber',s ,,notes #a4 ,typos fixed2 non-standard spelling and dialect retained4 #b4 ,used numbers for footnotes4 #c4 ,enclosed italics font in underscores4 #d4 ,enclosed bold or blackletter font in equals4 #e4 ,the caret 77 serves as a superscript indicator1 applicable to individual characters 7like #b;d7 and even entire phrases 7like #ast74 #f4 ,subscripts are shown using an underscore 77 with curly braces 1 as in ,h#b,o4