,,elements ,,of ,,agricultural ,,chemistry ,,by ,,thomas ,,anderson1 ,m4,d4 ,f4,r4,s4,e41 ,f4,c4,s4 ,,professor ,,of ,,chemistry ,,in ,,the ,,university ,,of ,,glasgow1 ,,and ,,chemist ,,to ,,the ,,highland ,,and ,,agricultural ,,society ,,of ,,scotland4 ,,edinburgh3 ,,adam ,,and ,,charles ,,black4 #ahfj4 ,,erratum4 ,page #aij1 line #aa1 for gallon read ton4 ,,printed ,,by ,r4 ,,and ,r4 ,,clark1 ,,edinburgh4 ,transcriber's note3 ,many of the tables needed to be split to fit space constraints4 ,minor typos have been corrected and footnotes moved to the end of the chapters4 ,a word surrounded by underscores like this signifies the word is italics in the text4 ,for numbers and equations1 underscores before bracketed numbers in equations denote a subscript4 ,,preface4 ,the object of the present work is to offer to the farmer a concise outline of the general principles of ,agricultural ,chemistry4 ,it has no pretensions to be considered a complete treatise on the subject4 ,on the contrary1 its aim is strictly elementary1 and with this view ,i have endeavoured1 as far as possible1 to avoid unnecessary technicalities so as to make it intelligible to those who are unacquainted with the details of chemical science1 although ,i have not hesitated to discuss such points as appeared essential to the proper understanding of any particular subject4 ,the rapid progress of agricultural chemistry1 and the numerous researches prosecuted under the auspices of agricultural societies and private experimenters in this and other countries1 render it by no means an easy task to make a proper selection from the mass of facts which is being daily accumulated4 ,in doing this1 however1 ,i have been guided by a pretty intimate knowledge of the wants of the farmer1 which has induced me to enlarge on those departments of the subject which bear more immediately on the every-day practice of agriculture2 and for this reason the composition and properties of soils1 the nature of manures1 and the principles by which their application ought to be governed1 have been somewhat minutely treated4 ,in all cases numerical details have been given as fully as is consistent with the limits of the work2 and it may be right to state that a considerable number of the analyses contained in it have been made in my own laboratory1 and that even when ,i have preferred to quote the results of other chemists1 they have not unfrequently been confirmed by my own experiments4 ,,university ,,of ,,glasgow1 #ast ,november #ahfj4 ,,contents4 ,page ,,introduction #a ,,chapter ,i4 ,,the ,,organic ,,constituents ,,of ,,plants4 ,carbon 444 ,carbonic ,acid 444 ,hydrogen 444 ,nitrogen 444 ,nitric ,acid 444 ,ammonia 444 ,oxygen 444 ,sources whence obtained 444 ,the ,atmosphere 444 ,the ,soil 444 ,source of the ,inorganic ,constituents of ,plants 444 ,manner in which the ,constituents of ,plants are absorbed #h ,,chapter ,,ii4 ,,the ,,proximate ,,constituents ,,of ,,plants4 ,the ,saccharine and ,amylaceous ,constituents 444 ,cellulose 444 ,incrusting ,matter 444 ,starch 444 ,lichen ,starch 444 ,inuline 444 ,gum 444 ,dextrine 444 ,sugar 444 ,mucilage 444 ,pectine and ,pectic ,acid 444 ,oily or ,fatty ,matters 444 ,margaric1 ,stearic1 and ,oleic ,acids 444 ,wax 444 ,nitrogenous or ,albuminous ,constituents of ,plants and ,animals 444 ,albumen 444 ,fibrine 444 ,casein 444 ,diastase #dj ,,chapter ,,iii4 ,,the ,,changes ,,which ,,take ,,place ,,in ,,the ,,food ,,of ,,plants ,,during ,,their ,,growth4 ,changes occurring during ,germination 444 ,changes during the ,after-,growth of the ,plant 444 ,decomposition of ,carbonic ,acid 444 ,decomposition of ,water 444 ,decomposition of ,ammonia 444 ,decomposition of ,nitric ,acid #ed ,,chapter ,,iv4 ,,the ,,inorganic ,,constituents ,,of ,,plants4 ,the ,amount of ,inorganic ,matters in ,different ,plants 444 ,the ,relative ,proportions of ,ash in the ,different ,parts of ,plants 444 ,influence of the ,nature of the ,soil on the ,proportion of ,mineral ,matters in the ,plant 444 ,the ,composition of the ,ashes of ,plants 444 ,classification of ,different ,plants #fc ,,chapter ,v4 ,,the ,,soil--,,its ,,chemical ,,and ,,physical ,,characters4 ,the ,origin of ,soils 444 ,composition of ,crystalline and ,sedimentary ,rocks 444 their ,disintegration 444 ,chemical ,composition of the ,soil 444 ,fertile and ,barren ,soils 444 ,mechanical ,texture of ,soils 444 ,absorbent ,action of ,soils 444 their ,physical ,characters 444 ,relation to ,heat and ,moisture 444 ,the ,subsoil 444 ,classification of ,soils #hc ,,chapter ,,vi4 ,,the ,,improvement ,,of ,,the ,,soil ,,by ,,mechanical ,,processes4 ,draining 444 ,its ,advantageous ,effects 444 ,subsoil and ,deep ,ploughing 444 ,improving the ,soil by ,paring and ,burning 444 ,warping 444 ,mixing of ,soils 444 ,chalking #acg ,,chapter ,,vii4 ,,the ,,general ,,principles ,,of ,,manuring4 ,fundamental ,principles upon which ,manures are applied 444 ,special and ,general ,manures 444 ,importance of this distinction 444 ,views regarding the ,theory of ,manures 444 ,remarks on ,special ,manures 444 ,action of ,manures on the ,chemical and ,physical ,properties of a ,soil 444 ,remarks on the ,application of ,manures #aeb ,,chapter ,,viii4 ,,the ,,composition ,,and ,,properties ,,of ,,farm-,,yard ,,and ,,liquid ,,manures4 ,farm-yard ,manure 444 ,urine 444 ,composition of 444 ,dung 444 ,composition of 444 ,farm-yard ,manure 444 ,composition of 444 ,management of ,dung-,heaps 444 ,box-feeding 444 ,fermentation and application of ,manure 444 ,liquid ,manure 444 ,composition and application of 444 ,sewage ,manure 444 ,its composition and application #aff ,,chapter ,,ix4 ,,the ,,composition ,,and ,,properties ,,of ,,vegetable ,,manures4 ,rape-,dust1 ,mustard1 ,cotton and ,castor ,cake 444 ,composition of various ,oil-,cakes 444 ,malt-,dust1 ,bran1 ,chaff1 etc4 444 ,straw and ,saw-dust 444 ,manuring with ,fresh ,vegetable ,matter 444 ,green ,manuring 444 ,sea-,weed 444 ,composition of various ,sea-,weeds 444 ,leaves 444 ,peat #aie ,,chapter ,x4 ,,the ,,composition ,,and ,,properties ,,of ,,animal ,,manures4 ,guano1 different varieties of 444 ,average composition of 444 ,division into ,ammoniacal and ,phosphatic 444 ,characters of 444 ,adulteration of 444 ,application of 444 ,pigeons' ,dung 444 ,urate and ,sulphated ,urine 444 ,night-,soil and ,poudrette 444 ,hair1 ,skin1 ,horn1 ,wool1 etc4 444 ,blood 444 ,fish 444 ,fish-,guano--,bones #bjd ,,chapter ,,xi4 ,,the ,,composition ,,and ,,properties ,,of ,,mineral ,,manures4 ,mineral ,manures 444 ,sulphate and ,muriate of ,ammonia 444 ,sulphomuriate of ,ammonia 444 ,ammoniacal ,liquor 444 ,nitrates of ,potash and ,soda 444 ,muriate and ,sulphate of ,potash 444 ,chloride of ,sodium1 or ,common ,salt 444 ,carbonates of ,potash and ,soda 444 ,silicates of ,potash and ,soda 444 ,sulphate of ,magnesia 444 ,phosphate of ,lime 444 ,bone-ash 444 ,coprolites 444 ,apatite 444 ,sombrero ,guano 444 ,superphosphates and ,dissolved ,bones 444 ,biphosphate of ,lime or ,soluble ,phosphates 444 ,phospho-,peruvian ,guano 444 ,lime 444 ,chalk 444 ,marl 444 ,application and ,action of ,lime on ,soils 444 ,sulphate of ,lime or ,gypsum #bbf ,,chapter ,,xii4 ,,the ,,valuation ,,of ,,manures4 ,the ,principle on which ,manures are valued 444 ,its application to different simple and complex ,manures 444 ,method of ,calculation 444 ,general ,remarks #bee ,,chapter ,,xiii4 ,,the ,,rotation ,,of ,,crops4 ,its necessity explained 444 ,quantity of ,mineral ,matters in the produce of an ,acre of ,different ,crops 444 ,the ,theory of ,rotation #bff ,,chapter ,,xiv4 ,,the ,,feeding ,,of ,,farm ,,stock4 ,the ,principles of ,feeding 444 ,the ,composition of different ,animals in different stages of ,fattening 444 ,the ,composition of the ,food of ,animals 444 ,milk 444 ,the ,principal ,varieties of ,cattle ,food 444 ,general ,observations on ,feeding #bgf ,,agricultural ,,chemistry4 ,,introduction4 ,that the phenomena of vegetation are dependent on certain chemical changes occurring in the plant1 by which the various elements of its food are elaborated and converted into vegetable matter1 was very early recognised by chemists2 and long before the correct principles of that science were established1 ,van ,helmont maintained that plants derived their nourishment from water1 while ,sir ,kenelm ,digby1 ,hook1 ,bradley1 and others1 attributed an equally exclusive influence to air1 and enlarged on the practical importance of the conclusions to be deduced from their views4 ,these opinions1 which were little better than hypotheses1 and founded on very imperfect chemical data1 are mentioned by ,jethro ,tull1 the father of modern agriculture1 only to deny their accuracy2 and he contended that the plants absorb and digest the finer particles of the earth1 and attributed the success of the particular system of husbandry he advocated to the comminution of the soil1 by which a larger number of its particles are rendered sufficiently small to permit their ready absorption by the roots4 ,popular opinion at that time was in favour of the mechanical rather than the chemical explanation of agricultural facts1 and ,tull's work had the effect of confirming this opinion1 and turning attention away from the application of chemistry to agriculture4 ,indeed1 no good results could have followed its study at that time1 for chemistry1 especially in those departments bearing more immediately on agriculture1 was much too imperfect1 and it was only towards the close of the last century1 when ,lavoisier established its true principles1 that it became possible to pursue it with any prospect of success4 ,very soon after ,lavoisier's system was made known1 ,lord ,dundonald published his ,treatise on the ,intimate ,connexion between ,chemistry and ,agriculture1 in which the important bearings of the recent chemical discoveries on the practice of agriculture were brought prominently under the notice of the farmer1 and almost at the same time ,de ,saussure commenced those remarkable researches1 which extended over a long series of years1 and laid the foundation of almost all our accurate knowledge of the chemistry of vegetation4 ,saussure traced with singular care and accuracy the whole phenomena of the life of plants1 and indicated the mode in which the facts he established might be taken advantage of in improving the cultivation of the soil4 ,but neither his researches1 nor ,lord ,dundonald's more direct appeal to the farmer1 excited the attention they deserved1 or produced any immediate effect on the progress of agriculture4 ,it was not till the year #ahab that the interest of practical men was fairly awakened by a course of lectures given by ,sir ,humphrey ,davy1 at the instance of ,sir ,john ,sinclair1 who was at that time president of the ,board of ,agriculture4 ,in these lectures1 written with all the clearness and precision which characterised their author's style1 the results of ,de ,saussure's experiments were for the first time presented to the farmer in a form in which they could be easily understood by him1 the conclusions to which they led were distinctly indicated1 and a number of useful practical suggestions made1 many of which have been adopted into every-day practice1 and become so thoroughly incorporated with it1 that their scientific origin has been altogether forgotten4 ,a lively interest was excited by the publication of ,davy's work1 but it soon died out1 and the subject lay in almost complete abeyance for a considerable number of years4 ,nor could any other result be well expected1 for at that time agriculture was not ripe for chemistry1 nor chemistry ripe for agriculture4 ,the necessities of a rapidly increasing population had not yet begun to compel the farmer to use every means adapted to increase the amount of production to its utmost limit2 and though the fundamental principles of chemistry had been established1 its details1 especially in that department which treats of the constituents of plants and animals1 were very imperfectly known4 ,it is not surprising1 therefore1 that matters should have remained almost unchanged for the comparatively long period of nearly thirty years4 ,indeed1 with the exception of the investigation of soils by ,schuebler1 and some other inquiries of minor importance1 and which1 in this country at least1 excited no attention on the part of the agriculturist1 nothing was done until the year #ahdj1 when ,liebig published his treatise on ,chemistry1 in its application to ,agriculture and ,physiology4 ,saussure's researches formed the main groundwork of ,liebig's treatise1 as they had before done for ,davy's2 but the progress of science had supplied many new facts which confirmed the opinions of the older chemists in most respects1 and enabled ,liebig to generalise with greater confidence1 and illustrate more fully the principles upon which chemistry ought to be applied to agriculture4 ,few works have ever produced a more profound impression4 ,written in a clear and forcible style1 dealing with scientific truths in a bold and original manner1 and producing a strong impression1 as well by its earnestness as by the importance of its conclusions1 it was received by the agricultural public with the full conviction that the application of its principles was to be immediately followed by the production of immensely increased crops1 and by a rapid advance in every branch of practical agriculture4 ,the disappointment of these extravagant expectations1 which chemists themselves foresaw1 and for which they vainly attempted to prepare the agriculturist1 was followed by an equally rapid reaction2 and those who had embraced ,liebig's views1 and lauded them as the commencement of a new era1 but who had absurdly expected an instantaneous effect1 changed their opinion1 and contemned1 as strongly as they had before supported1 the application of chemistry to agriculture4 ,that this effect should have been produced is not unnatural2 for practical men1 having at that time little or no knowledge of chemistry1 were necessarily unable to estimate its true position in relation to agriculture1 and forgetting that this department of science was still in its early youth1 and burthened with all the faults and errors of youth1 they treated it as if it were already perfect in all its parts4 ,neither could they distinguish between the fully demonstrated scientific truths1 and the uncertain1 though probable conclusions deduced from them2 and when the latter1 as occasionally happened1 proved to be at variance with practice1 it is not surprising3 that this should have produced a feeling of distrust on the part of persons incapable1 from an imperfect1 and still oftener from no knowledge of science1 of drawing the line of demarcation1 which ,liebig frequently omitted to do1 between the positive fact and the hypothetical inference1 which1 however probable1 is1 after all1 merely a suggestion requiring to be substantiated by experiment4 ,this omission1 which the scientific reader can supply for himself1 becomes a source of serious misapprehension in a work addressed to persons unacquainted with science1 who adopt indiscriminately both the facts and the hypotheses of the author4 ,and this is no doubt the cause of the vary different estimation in which the work of the ,giessen ,professor was held by scientific and practical men4 ,liebig's treatise was followed1 in the year #ahdd1 by the publication of ,boussingault's ,economic ,rurale1 a work winch excited at the time infinitely less interest than ,liebig's1 although it is really quite as important a contribution to scientific agriculture4 ,it is distinguished by entering more fully into the special details of the application of chemistry to agriculture1 and contains the results of the author's numerous searches both in the laboratory and the field4 ,boussingault possesses the qualification1 at present somewhat rare1 of combining a thorough knowledge of practical agriculture with extended scientific attainments2 and his investigations1 which have been made with direct reference to practice1 and their results tested in the field1 are the largest and most valuable contribution to the exact data of scientific agriculture which has yet been made public4 ,the year #ahdd was also distinguished by the foundation of the ,agricultural ,chemistry ,association of ,scotland1 an event of no small importance in the history of scientific agriculture4 ,that association was instituted through the exertions of a small number of practical farmers1 for the purpose of pursuing investigations in agricultural chemistry1 and affording to its members assistance in all matters connected with the cultivation of the soil1 and has formed the model of similar establishments in ,london1 ,dublin1 and ,belfast1 as well as in ,germany2 and it is peculiarly creditable to the intelligence and energy of the practical farmers of ,scotland1 that with them commenced a movement1 which has already found imitators in so many quarters1 and conferred such great benefits on agriculture4 ,within the last ten or twelve years1 and mainly owing to the establishment of agricultural laboratories1 great progress has been made in accumulating facts on which to found an accurate knowledge of the principles of agricultural chemistry1 and the number of chemists who have devoted themselves to this subject has considerably increased1 though still greatly less than its exigencies require4 ,notwithstanding all that has recently been done1 it must not be forgotten that we have scarcely advanced beyond the threshold1 and that it is only by numerous and frequently repeated experiments that it is possible to arrive at satisfactory results4 ,agricultural inquiries are liable to peculiar fallacies due to the perturbing influence of climate1 season1 and many other causes1 the individual effects of which can only be eliminated with difficulty1 and much error has been introduced1 by hastily generalising from single experiments1 in place of awaiting the results of repeated trials4 ,hence it is that the progress of scientific agriculture must necessarily be slow and gradual1 and is not likely to be marked by any great or startling discoveries4 ,now that the relations of science to practice are better understood1 the extravagant expectations at one time entertained have been abandoned1 and1 as a necessary consequence1 the interest in agricultural chemistry has again increased1 and the conviction daily gains ground that no one who wishes to farm with success1 can afford to be without some knowledge of the scientific principles of his art4 ,,chapter ,i4 ,,the ,,organic ,,constituents ,,of ,,plants4 ,when the water naturally existing in plants is expelled by exposure to the air or a gentle heat1 the residual dry matter is found to be composed of a considerable number of different substances1 which have been divided into two great classes1 called the organic and the inorganic1 or mineral constituents of plants4 ,the former are readily combustible1 and on the application of heat1 catch fire1 and are entirely consumed1 leaving the inorganic matters in the form of a white residuum or ash4 ,all plants contain both classes of substances2 and though their relative proportions vary within very wide limits1 the former always greatly exceed the latter1 which in many cases form only a very minute proportion of the whole weight of the plant4 ,owing to the great preponderance of the organic or combustible matters1 it was at one time believed that the inorganic substances formed no part of the true structure of plants1 and consisted only of a small portion of the mineral matters of the soil1 which had been absorbed along with their organic food2 but this opinion1 which probably was never universally entertained1 is now entirely abandoned1 and it is no longer doubted that both classes of substances are equally essential to their existence4 ,although they form so large a proportion of the plant1 its organic constituents are composed of no more than four elements1 viz43-- ,carbon4 ,hydrogen4 ,nitrogen4 ,oxygen4 ,the inorganic constituents are much more numerous1 not less than thirteen substances1 which appear to be essential1 having been observed4 ,these are-- ,potash4 ,soda4 ,lime4 ,magnesia4 ,peroxide of ,iron4 ,silicic ,acid4 ,phosphoric ,acid4 ,sulphuric ,acid4 ,chlorine4 ,and more rarely ,manganese4 ,iodine4 ,bromine4 ,fluorine4 ,several other substances1 among which may be mentioned alumina and copper1 have also been enumerated2 but there is every reason to believe that they are not essential1 and the cases in which they have been found are quite exceptional4 ,it is to be especially noticed that none of these substances occur in plants in the free or uncombined state1 but always in the form of compounds of greater or less complexity1 and extremely varied both in their properties and composition4 ,it would be out of place1 in a work like the present1 to enter into complete details of the properties of the elements of which plants are composed1 which belongs strictly to pure chemistry1 but it is necessary to premise a few observations regarding the organic elements1 and their more important compounds4 ,carbon4--,when a piece of wood is heated in a close vessel1 it is charred1 and converted into charcoal4 ,this charcoal is the most familiar form of carbon1 but it is not absolutely pure1 as it necessarily contains the ash of the wood from which it was made4 ,in its purest form it occurs in the diamond1 which is believed to be produced by the decomposition of vegetable matters1 and it is there crystallized and remarkably transparent2 but when produced by artificial processes1 carbon is always black1 more or less porous1 and soils the fingers4 ,it is insoluble in water1 burns readily1 and is converted into carbonic acid4 ,carbon is the largest constituent of plants1 and forms1 in round numbers1 about #ej per cent of their weight when dry4 ,carbonic ,acid4--,this1 the most important compound of carbon and oxygen1 is best obtained by pouring a strong acid upon chalk or limestone1 when it escapes with effervescence4 ,it is a colourless gas1 extinguishing flame1 incapable of supporting respiration1 much heavier than atmospheric air1 and slightly soluble in water1 which takes up its own volume of the gas4 ,it is produced abundantly when vegetable matters are burnt1 as also during respiration1 fermentation1 and many other processes4 ,it is likewise formed daring the decay of animal and vegetable matters1 and is consequently evolved from dung and compost heaps4 ,hydrogen occurs in nature only in combination4 ,its principal compound is water1 from which it is separated by the simultaneous action of an acid1 such as sulphuric acid and a metal1 in the form of a transparent gas1 lighter than any other substance4 ,it is very combustible1 burns with a pale blue flame1 and is converted into water4 ,it is found in all plants1 although in comparatively small quantity1 for1 when dry1 they rarely contain more than four or five per cent4 ,its most important compound is water1 of which it forms one-ninth1 the other eight-ninths consisting of oxygen4 ,nitrogen exists abundantly in the atmosphere1 of which it forms nearly four-fifths1 or1 more exactly1 #gi per cent4 ,it is there mixed1 but not combined with oxygen2 and when the latter gas is removed1 by introducing into a bottle of air some substance for which the former has an affinity1 the nitrogen is left in a state of purity4 ,it is a transparent gas1 which is incombustible and extinguishes flame4 ,it is a singularly inert substance1 and is incapable of directly entering into union with any other element except oxygen1 and with that it combines with the greatest difficulty1 and only by the action of the electric spark--a peculiarity which has very important bearings on many points we shall afterwards have to discuss4 ,nitrogen is found in plants to the extent of from #a to #d per cent4 ,nitric ,acid4--,this1 the most important compound of nitrogen and oxygen1 can be produced by sending a current of electric sparks through a mixture of its constituents1 but in this way it can be obtained only in extremely small quantity4 ,it is much more abundantly produced when organic matters are decomposed with free access of air1 in which case the greater proportion of their nitrogen combines with the atmospheric oxygen4 ,this process1 which is known by the name of nitrification1 is greatly promoted by the presence of lime or some other substance1 with which the nitric acid may combine in proportion as it is formed4 ,it takes place1 to a great extent1 in the soil in ,india and other hot climates2 and our chief supplies of saltpetre1 or nitrate of potash1 are derived from the soil in these countries1 where it has been formed in this manner4 ,the same change occurs1 though to a much smaller extent1 in the soil in temperate climates4 ,ammonia is a compound of nitrogen and hydrogen1 but it cannot be formed by the direct union of these gases4 ,it is a product of the decomposition of organic substances containing nitrogen1 and is produced when they are distilled at a high temperature1 or allowed to putrefy out of contact of the air4 ,in its pure state it is a transparent and colourless gas1 having a peculiar pungent smell1 and highly soluble in water4 ,it is an alkali resembling potash and soda1 and1 like these substances1 unites with the acids and forms salts1 of which the sulphate and muriate are the most familiar4 ,in these salts it is fixed1 and does not escape from them unless they be mixed with lime1 or some other substance possessing a more powerful affinity for the acid with which it is united4 ,oxygen is one of the most widely distributed of all the elements1 and1 owing to its powerful affinities1 is the most important agent in almost all natural changes4 ,it is found in the air1 of which it forms #ba per cent1 and in combination with hydrogen1 and almost all the other chemical elements4 ,in the pure state it possesses very remarkable properties4 ,all substances burn in it with greater brilliancy than they do in atmospheric air1 and its affinity for most of the elements is extremely powerful4 ,when diluted with nitrogen1 it supports the respiration of animals2 but in the pure state it proves fatal after the lapse of an hour or two4 ,it is found in plants1 in quantities varying from #cj to #cf per cent4 ,it is worthy of observation1 that of the four organic elements1 carbon only is fixed1 and the other three are gases2 and likewise1 when any two of them unite1 their compound is either a gaseous or a volatile substance4 ,the charring of organic substances1 which is one of their most characteristic properties1 and constantly made use of by chemists as a distinctive reaction1 is due to this peculiarity2 for when they are heated1 a simpler arrangement of their particles takes place1 the hydrogen1 nitrogen1 and oxygen unite among themselves1 and carry off a small quantity of carbon1 while the remainder is left behind in the form of charcoal1 and is only consumed when access of the external air is permitted4 ,now1 in order that a plant may grow1 its four organic constituents must be absorbed by it1 and that this absorption may take place1 it is essential that they be presented to it in suitable forms4 ,a seed may be planted in pure carbon1 and supplied with unlimited quantities of hydrogen1 nitrogen1 oxygen1 and inorganic substances1 and it will not germinate2 and a plant1 when placed in similar circumstances1 shows no disposition to increase1 but rapidly languishes and dies4 ,the obvious inference from these facts is1 that these substances cannot be absorbed when in the elementary state1 but that it is only after they have entered into certain forms of combination that they acquire the property of being readily taken up1 and assimilated by the organs of the plant4 ,it was at one time believed that many different compounds of these elements might be absorbed and elaborated1 but later and more accurate experiments have reduced the number to four--namely1 carbonic acid1 water1 ammonia1 and nitric acid4 ,the first supplies carbon1 the second hydrogen1 the two last nitrogen1 while all of them1 with the exception of ammonia1 may supply the plant with oxygen as well as with that element of which it is the particular source4 ,there are only two sources from which these substances can be obtained by the plant1 viz4 the atmosphere and the soil1 and it is necessary that we should here consider the mode in which they may be obtained from each4 ,the ,atmosphere as a source of the ,organic ,constituents of ,plants4--,atmospheric air consists of a mixture of nitrogen and oxygen gases1 watery vapour1 carbonic acid1 ammonia1 and nitric acid4 ,the two first are the largest constituents1 and the others1 though equally essential1 are present in small1 and some of them in extremely minute quantity4 ,when deprived of moisture and its minor constituents1 #ajj volumes of air are found to contain #ba of oxygen and #gi of nitrogen4 ,although these gases are not chemically combined in the air1 but only mechanically mixed1 their proportion is exceedingly uniform1 for analyses completely corresponding with these numbers have been made by ,humboldt1 ,gay-,lussac1 and ,dumas at ,paris1 by ,saussure at ,geneva1 and by ,lewy at ,copenhagen2 and similar results have also been obtained from air collected by ,gay-,lussac during his ascent in a balloon at the height of #ba1dcj feet1 and by ,humboldt on the mountain of ,antisano in ,south ,america at a height of #af1fdj feet4 ,in short1 under all circumstances1 and in all places1 the relation subsisting between the oxygen and nitrogen is constant2 and though1 no doubt1 many local circumstances exist which may tend to modify their proportions1 these are so slow and partial in their operations1 and so counterbalanced by others acting in an opposite direction1 as to retain a uniform proportion between the main constituents of the atmosphere1 and to prevent the undue accumulation of one or other of them at any one point4 ,no such uniformity exists in the proportion of the minor constituents4 ,the variation in the quantity of watery vapour is a familiar fact1 the difference between a dry and moist atmosphere being known to the most careless observer1 and the proportions of the other constituents are also liable to considerable variations4 ,carbonic ,acid4--,the proportion of carbonic acid in the air has been investigated by ,saussure4 ,from his experiments1 made at the village of ,chambeisy1 near ,geneva1 it appears that the quantity is not constant1 but varies from #c4ae to #e4ge volumes in #aj1jjj2 the mean being #d4ae4 ,these variations are dependent on different circumstances4 ,it was found that the carbonic acid was always more abundant during the night than during the day--the mean quantity in the former case being #d4cb1 in the latter #c4ch4 ,the largest quantity found during the night was #e4gd1 during the day #e4d4 ,heavy and continued rain diminishes the quantity of carbonic acid1 by dissolving and carrying it down into the soil4 ,saussure found that in the month of ,july #ahbg1 during the time when nine millimetres of rain fell1 the average quantity of carbonic acid amounted to #e4ah volumes in #aj1jjj2 while in ,september #ahbi1 when #bed millimetres fell1 it was only #c4eg4 ,a moist state of the soil1 which is favourable to the absorption of carbonic acid1 also diminishes the quantity contained in the air1 while1 on the other hand1 continued frosts1 by retaining the atmosphere and soil in a dry state1 have an opposite effect4 ,high winds increase the carbonic acid to a small extent4 ,it was also found to be greater over the cultivated lands than over the lake of ,geneva2 at the tops of mountains than at the level of the sea2 in towns than in the country4 ,the differences observed in all these cases1 though small1 are quite distinct1 and have been confirmed by subsequent experimenters4 ,ammonia4--,the presence of ammonia in the atmosphere appears to have been first observed by ,saussure1 who found that when the sulphate of alumina is exposed to the air1 it is gradually converted into the double sulphate of alumina and ammonia4 ,liebig more recently showed that ammonia can always be detected in rain and snow water1 and it could not be doubted that it had been absorbed from the atmosphere4 ,experiments have since been made by different observers with the view of determining the quantity of atmospheric ammonia1 and their results are contained in the subjoined table1 which gives the quantity found in a million parts of air4 ,kemp #c4fhjj #ab feet above the surface #c4ejjj ,pierre #be feet do4 do4 #j4ejjj ,graeger #j4cbcj ,by day #j4jihj ,fresenius ,by night #j4afij ,maximum #j4jcag ,in ,paris ,minimum #j4jagg ,mean #j4jbcg ,ville ,maximum #j4jbgf ,environs ,minimum #j4jafe of ,paris ,mean #j4jbaj ,of these results1 the earlier ones of ,kemp1 ,pierre1 and ,graeger are undoubtedly erroneous1 as they were made without those precautions which subsequent experience has shown to be necessary4 ,even those of the other observers must be taken as giving only a very general idea of the quantity of ammonia in the air1 for a proportion so minute as one fifty-millionth cannot be accurately determined even by the most delicate experiments4 ,for this reason1 more recent experimenters have endeavoured to arrive at conclusions bearing more immediately upon agricultural questions1 by determining the quantity of ammonia brought down by the rain4 ,the first observations on this subject were made by ,barral in #ahea1 and they have been repeated during the years #ahee and #ahef by ,mr4 ,way4 ,in #ahec1 ,boussingault also made numerous experiments on the quantity of ammonia in the rain falling at different places1 as well as in dew and the moisture of fogs4 ,he found in the imperial gallon-- ,grs4 ,rain ,paris #j4bajj ,liebfrauenberg #j4jcej ,dew1 ,liebfrauenberg ,maximum #j4dcdj ,minimum #j4jgad ,liebfrauenberg #j4agij ,fog ,paris #i4fjjj ,it thus appears that in ,paris the quantity of ammonia in rain-water is just six times as great as it is in the country1 a result1 no doubt1 due to the ammonia evolved during the combustion of fuel1 and to animal exhalations1 and to the same cause1 the large quantity contained in the moisture of fogs in ,paris may also be attributed4 ,barral and ,way have made determinations of the quantity of ammonia carried down by the rain in each month of the year1 the former using for this purpose the water collected in the rain-gauges of the ,paris ,observatory1 and representing1 therefore1 a town atmosphere2 the latter1 that from a large rain-gauge at ,rothamsted1 at a distance from any town4 ,according to ,barral the ammonia annually deposited on an acre of land amounts to #ab4bh lbs41 a quantity considerably exceeding that obtained by ,way1 whose experiments being made at a distance from towns1 must be considered as representing more accurately the normal condition of the air4 ,his results for the years #ahee and #ahef are given below1 along with the quantities of nitric acid found at the same time4 ,nitric ,acid4--,the presence of nitric acid in the air appears to have been first observed by ,priestley at the end of the last century1 but ,liebig1 in #ahbe1 showed that it was always to be found after thunder-storms1 although he failed to detect it at other times4 ,in #ahea ,barral proved that it is invariably present in rain-water1 and stated the quantity annually carried down to an acre of land at no less than #da4bi lbs4 ,but at the time his experiments were made1 the methods of determining very minute quantities of nitric acid were exceedingly defective1 and ,way1 by the adoption of an improved process1 has shown that the quantity is very much smaller than ,barral supposed1 and really falls short of three pounds4 ,his results for ammonia1 as well as nitric acid1 are given in the subjoined table4 ---------------------------------------- ------------------------------ ,nitric ,acid in ,ammonia in ,total ,nitrogen ,grains4 ,grains4 in ,grains4 ---------------------------------------- ------ #ahee4 #ahef4 #ahee4 #ahef4 #ahee4 #ahef4 ---------------------------------------- -------------------------- ,january #bcj #aefd #abdd #e1jje #ajhd #d1ebf ,february #idd #edd #bccg #d1age #bafi #c1egi ,march #aajb #hff #deac #b1ajh #ciie #a1ide ,april #cbe #ajfc #aada #h1fad #ajbd #g1cfi ,may #ahdj #cjbd #dbjf #ah1cac #cici #ae1hfc ,june #ccjc #bjdf #eegd #d1hgj #eddg #d1edj ,july #bfhj #aaia #ifbj #b1hfi #hfae #b1fgj ,august #cegg #babe #dgfi #d1bad #dhgj #d1jba ,september #gcb #agef #ccac #e1igb #biag #e1cgc ,october #ddhj #bjge #geib #c1iba #gdad #c1gfg ,november #ajjg #acga #cjba #b1eia #bgdi #b1dhi ,december #ffd #bjce #bdch #d1jgj #bahj #c1ceb ---------------------------------------- -------------------------- ,total in pounds for the whole year #b4ih 4#bhj #g4aa #i4ec #f4fc #h4ca ---------------------------------------- --------------------------- ,no attempts have been made to determine the proportion of nitric acid in air1 but its quantity is undoubtedly excessively minute1 and materially smaller than that of ammonia4 ,at least this conclusion seems to be a fair inference from ,way's researches1 as well as the recent experiments of ,boussingault on the proportion of nitric acid contained in rain1 dew1 and fog1 made in a manner exactly similar to those on the ammonia1 already quoted4 ,according to his experiments an imperial gallon contains-- ,grs4 ,rain4 ,paris #j4jgjh ,liebfrauenberg #j4jadj ,dew4 ,maximum #j4jghe ,minimum #j4jjcj ,fog4 ,paris #j4gjib ,liebfrauenberg #j4jgah ,although it thus appears that ,barral's results have been only partially confirmed1 enough has been ascertained to show that the quantity of ammonia and nitric acid in the air is sufficient to produce a material influence in the growth of plants4 ,the large amount of these substances contained in the dew is also particularly worthy of notice1 and may serve to some extent to explain its remarkably invigorating effect on vegetation4 ,carburetted ,hydrogen4--,gay-,lussac1 ,humboldt1 and ,boussingault have shown1 that when the whole of the moisture and carbonic acid have been removed from the air1 it still contains a small quantity of carbon and hydrogen2 and ,saussure has rendered it probable that they exist in a state of combination as carburetted hydrogen gas4 ,no definite proof of this position has1 however1 as yet been adduced1 and the function of the compound is entirely unknown4 ,it is possible that the presence of carbon and hydrogen may be due to a small quantity of organic matter2 but1 whatever be its source1 its amount is certainly extremely small4 ,sulphuretted ,hydrogen and ,phosphuretted ,hydrogen4--,the proportion of these substances is almost infinitesimal2 but they are pretty general constituents of the atmosphere1 and are apparently derived from the decomposition of animal and vegetable matters4 ,the preceding statements lead to the important conclusion1 that the atmosphere is capable of affording an abundant supply of all the organic elements of plants1 because it not only contains nitrogen and oxygen in the free state1 but also in those forms of combination in which they are most readily absorbed1 as well as a large quantity of carbonic acid1 from which their carbon may be derived4 ,at first sight it may indeed appear that the quantity of the latter compound1 and still more that of ammonia1 is so trifling as to be of little practical importance4 ,but a very simple calculation serves to show that1 though relatively small1 they are absolutely large1 for the carbonic acid contained in the whole atmosphere amounts in round numbers to #b1djj1jjj1jjj1jjj tons1 and the ammonia1 assuming it not to exceed one part in fifty millions1 must weigh #gd1jjj1jjj tons1 quantities amply sufficient to afford an abundant supply of these elements to the whole vegetation of our globe4 ,the ,soil as a ,source of the ,organic ,constituents of ,plants4--,when a portion of soil is subjected to heat1 it is found that it1 like the plant1 consists of a combustible and an incombustible part2 but while in the plant the incombustible part or ash is small1 and the combustible large1 these proportions are reversed in the soil1 which consists chiefly of inorganic or mineral matters1 mixed with a quantity of combustible or organic substances1 rarely exceeding #h or #aj per cent1 and often falling considerably short of this quantity4 ,the organic matter exists in the form of a substance called humus1 which must be considered here as a source of the organic constituents of plants1 independently of the general composition of the soil1 which will be afterwards discussed4 ,the term humus is generic1 and applied by chemists to a rather numerous group of substances1 very closely allied in their properties1 several of which are generally present in all fertile soils4 ,they have been submitted to examination by various chemists1 but by none more accurately than by ,mulder and ,herman1 to whom1 indeed1 we owe almost all the precise information we possess on the subject4 ,the organic matters of the soil may be divided into three great classes2 the first containing those substances which are soluble in water2 the second1 those extracted by means of caustic potash2 and the third1 those insoluble in all menstrua4 ,when a soil is boiled with a solution of caustic potash1 a deep brown fluid is obtained1 from which acids precipitate a dark brown flocculent substance1 consisting of a mixture of at least three different acids1 to which the names of humic1 ulmic1 and geic acids have been applied4 ,the fluid from which they have been precipitated contains two substances1 crenic and apocrenic acids1 while the soil still retains what has been called insoluble humus4 ,the acids above named do not differ greatly in chemical characters1 but they have been subdivided into the humic1 geic1 and crenic groups1 which present some differences in properties and composition4 ,they are compounds of carbon1 hydrogen1 and oxygen1 and are characterised by so powerful an affinity for ammonia that they are with difficulty obtained free from that substance1 and generally exist in the soil in combination with it4 ,they are all products of the decomposition of vegetable matters in the soil1 and are formed during their decay by a succession of changes1 which may be easily traced by observing the course of events when a piece of wood or any other vegetable substance is exposed for a length of time to air and moisture4 ,it is then found gradually to disintegrate with the evolution of carbonic acid1 acquiring first a brown and finally a black colour4 ,at one particular stage of the process it is converted into one or other of two substances1 called humin and ulmin1 both insoluble in alkalies1 and apparently identical with the insoluble humus of the soil2 but when the decomposition is more advanced the products become soluble in alkalies1 and then contain humic1 ulmic1 and geic acids1 and finally1 by a still further progress1 crenic and apocrenic acids are formed as the result of an oxidation occurring at certain periods of the decay4 ,the roots and other vegetable debris remaining in the soil undergo a similar series of changes1 and form the humus1 which is found only in the surface soil1 that is to say1 in the portion which is now or has at some previous period been occupied by plants1 and the quantity of humus contained in any soil is mainly dependent on the activity of vegetation on it4 ,numerous analyses of humus compounds extracted from the soil have been made1 and have served to establish a number of minor differences in the composition even of those to which the same name has been applied1 due manifestly to the fact that their production is the result of a gradual decomposition1 which renders it impossible to extract from the soil one pure substance1 but only a variable mixture of several1 so similar to one another in properties1 that their separation is very difficult1 if not impossible4 ,for this reason great discrepancies exist in the statements made regarding them by different observers1 but this is a matter of comparatively small importance1 as their exact composition has no very direct bearing on agricultural questions1 and it will suffice to give the names and chemical formulae of those which have been analysed and described1-- ,ulmic acid from long ,frisian turf ,c#dj ,h#ah ,o#af ,humic acid from hard turf ,c#dj ,h#ae ,o#ae ,humic acid from arable soil ,c#dj ,h#af ,o#af ,humic acid from a pasture field ,c#dj ,h#ad ,o#ad ,geic acid ,c#dj ,h#ae ,o#ag ,apocrenic acid ,c#dh ,h#ab ,o#bd ,crenic acid ,c#bd ,h#ab ,o#af ,it is only necessary to observe further1 that these formulae indicate a close connection with woody fibre1 and the continuous diminution of the hydrogen and increase of oxygen shows that they must have been produced by a gradually advancing decay4 ,the earlier chemists and vegetable physiologists attributed to the humus of the soil a much more important function than it is now believed to possess4 ,it was formerly considered to be the exclusive1 or at least the chief source of the organic constituents of plants1 and by absorption through the roots to yield to them the greater part of their nutriment4 ,but though this view has still some supporters1 among whom ,mulder is the most distinguished1 it is now generally admitted that humus is not a direct source of the organic constituents of plants1 and is not absorbed as such by their roots1 although it is so indirectly1 in as far as the decomposition which it is constantly undergoing in the soil yields carbonic acid1 which can be absorbed4 ,the older opinion is refuted by many well-ascertained facts4 ,as regards the exclusive origin of the carbon of plants from humus1 it is easy to see that this at least cannot be true1 for humus1 as already stated1 is itself derived solely from the decomposition of vegetable and animal matters2 and if the plants on the earth's surface were to be supported by it alone1 the whole of their substance would have to return to the soil in the same form1 in order to supply the generation which succeeds them4 ,but this is very far from being the case1 for the respiration of animals1 the combustion of fuel1 and many other processes1 are annually converting a large quantity of these matters into carbonic acid2 and if there were no other source of carbon but the humus of the soil1 the amount of vegetable life would gradually diminish1 and at length become entirely extinct4 ,schleiden1 who has discussed this subject very fully1 has made an approximative calculation of the total quantity of humus on the earth's surface1 and of the carbon annually converted into carbonic acid by the respiration of man and animals1 the combustion of wood for fuel1 and other minor processes2 and he draws the conclusion that1 if there were no other source of carbon except humus1 the quantity of that substance existing in the soil would only support vegetation for a period of sixty years4 ,the particular phenomena of vegetation also afford abundant evidence that humus cannot be the only source of carbon4 ,thus ,boussingault has shown that on the average of years1 the crops cultivated on an acre of land remove from it about one ton more organic matter than they receive in the manure applied to them1 although there is no corresponding diminution in the quantity of humus contained in the soil4 ,an instance which leads still more unequivocally to the same conclusion is given by ,humboldt4 ,he states that an acre of land1 planted with bananas1 yields annually about #aeb1jjj pounds weight of fruit1 containing about #cb1jjj pounds1 or almost exactly #ad tons of carbon2 and as this production goes on during a period of twenty years1 there must be withdrawn in that time no less than #bhj tons of carbon4 ,but the soil on an acre of land weighs1 in round numbers1 #ajjj tons1 and supposing it to contain #d per cent of humus1 the total weight of carbon in it would amount to little more than #bj tons4 ,it is obvious from these and many other analogous facts that humus cannot be the only or even a considerable source of the carbon of plants1 although it is still contended by some chemists that it may be absorbed to a small extent4 ,but even this is at variance with many well-known facts4 ,for if humus were absorbed1 it might be expected that vegetation would be most luxuriant on soils containing abundance of that substance1 especially if it existed in a soluble and readily absorbable form2 but so far from this being the case1 nothing is more certain than that peat1 in which these conditions are fulfilled1 is positively injurious to most plants4 ,on the other hand1 our daily experience affords innumerable examples of plants growing luxuriantly in soils and places where no humus exists4 ,the sands of the sea-shore1 and the most barren rocks1 have their vegetation1 and the red-hot ashes which are thrown out by active volcanoes are no sooner cool than a crop of plants springs up on them4 ,the conclusions to be drawn from these considerations have been further confirmed by the direct experiments of different observers4 ,boussingault sowed peas1 weighing #ae4fj grains1 in a soil composed of a mixture of sand and clay1 which had been heated red-hot1 and consequently contained no humus1 and after #ii days' growth1 during which they had been watered with distilled water1 he found the crop to weigh #fh4gb grains1 so that there had been a fourfold increase4 ,similar experiments have been made by ,prince ,salm ,horstmar1 on oats and rape sown in a soil deprived of organic matter by ignition1 in which they grew readily1 and arrived at complete maturity4 ,one oat straw attained a height of three feet1 and bore #gh grains2 another bore #dg2 and a third #bh--;in all #aec4 ,these when dried at #bab deg4 weighed #df4cjb grains1 and the straw #de4f grains4 ,the most satisfactory experiments1 however1 are those of ,weigman and ,polstorf1 these observers having found that it was possible to obtain a two-hundred-fold produce of barley in an entirely artificial soil1 provided care was taken to give it the physical characters of a fertile soil4 ,they prepared a mixture of six parts of sand1 two of chalk1 one of white bole1 and one of wood charcoal2 to which was added a small quantity of felspar1 previously fused with marble and some soluble salts1 so as to imitate as closely as possible the inorganic parts of a soil1 and in it they planted twelve barley pickles4 ,the plants grew luxuriantly1 reaching a height of three feet1 and each bearing nine ears1 containing #bb pickles4 ,the grain of the twelve plants weighed #bjdj grains4 ,these experiments show that plants can grow and produce seed when the most scrupulous care is taken to deprive them of every trace of humus4 ,but ,saussure has gone further1 and shown that even when present1 humus is not absorbed4 ,he allowed plants of the common bean and the ,polygonum ,persicaria to grow in solutions of humate of potash1 and found a very trifling diminution in the quantity of humic acid present2 but the value of his experiments is invalidated by his having omitted to ascertain whether the diminution of humic acid which he observed was really due to absorption by the plant4 ,this omission has been supplied by ,weigman and ,polstorf4 ,they grew plants of mint 7,mentha undulata7 and of ,polygonum ,persicaria in solutions of humate of potash1 and placed beside the glass containing the plant1 another perfectly similar1 and containing only the solution of humate of potash4 ,the solution1 which contained in every #ajj grains1 #j4adh grains of solid matter1 consisting of humate of potash1 etc4 was found to become gradually paler1 and at the end of a month1 during which time the plants had increased by #f-a_/b inches1 the quantity of solid matter in #ajj grains had diminished to #j4acb4 ,but the solution contained in the other glass1 and in which no plant had grown1 had diminished to #j4acf1 so that the absorption could not have amounted to more than #j4jjd grains for every #ajj grains of solution employed4 ,this quantity is so small as to be within the limits of error of experiment1 and we are consequently entitled to draw the conclusion that humus1 even under the most favourable circumstances1 is not absorbed by plants4 ,but though not directly capable of affording nutriment to plants1 it must not1 on that account1 be supposed that humus is altogether devoid of importance1 for it is constantly undergoing decomposition in the soil1 and thus becomes a source of carbonic acid which can be absorbed1 and1 as we shall afterwards more particularly see1 it exercises very important functions in bringing the other constituents of the soil into readily available forms of combination4 ,it has been already observed that carbon1 hydrogen1 nitrogen1 and oxygen1 cannot be absorbed by plants when uncombined1 but only in the forms of water1 carbonic acid1 ammonia1 and nitric acid4 ,it is scarcely necessary to detail the grounds on which this conclusion has been arrived at in regard to carbon and hydrogen1 for practically it is of little importance whether they can be absorbed or not1 as the former is rarely1 the latter never1 found uncombined in nature4 ,neither can there be any doubt that water and carbonic acid are the only substances from which these elements can be obtained4 ,every-day experience convinces us that water is essential to vegetation2 and ,saussure1 and other observers1 have shown that plants will not grow if they are deprived of carbonic acid1 and that they actually absorb that substance abundantly from the atmosphere4 ,the evidence for the non-absorption of oxygen lies chiefly in the fact that plants obtain1 in the form of water and carbonic acid1 a larger quantity of that element than they require1 and in place of absorbing1 are constantly exhaling it4 ,the form in which nitrogen may be absorbed has given rise to much difference of opinion4 ,in the year #aggi1 ,priestley commenced the examination of this subject1 and drew from his experiments the conclusion1 that plants absorb the nitrogen of the air4 ,saussure shortly afterwards examined the same subject1 and having found1 that when grown in a confined space of air1 and watered with pure water1 the nitrogen of the plants underwent no increase1 he inferred that they derived their entire supplies of that element from ammonia1 or the soluble nitrogenous constituents of the soil or manure4 ,boussingault has since re-examined this question1 and by a most elaborate series of experiments1 in which the utmost care was taken to avoid every source of fallacy1 he was led to the conclusion1 that when haricots1 oats1 lupins1 and cresses were grown in calcined pumice-stone1 mixed with the ash of plants1 and supplied with air deprived of ammonia and nitric acid1 their nitrogen underwent no increase4 ,it has been objected to these experiments1 that the plants being confined in a limited bulk of air1 were placed in an unnatural condition1 and ,ville has recently repeated them with a current of air passing through the apparatus1 and found a slight increase in the nitrogen1 due1 as he thinks1 to direct absorption4 ,it is much more probable1 however1 that it depends on small quantities of ammonia or nitric acid which had not been completely removed from the air by the means employed for that purpose1 for nothing is more difficult than the complete abstraction of these substances1 and as the gain of nitrogen was only #j4h grains1 while #fj1jjj gallons of air1 and #ac of water1 were employed in the experiment1 which lasted for a considerable time1 it is reasonable to suppose that a sufficient quantity may have remained to produce this trifling increase4 ,while these experiments show that plants maintain only a languid existence when grown in air deprived of ammonia and nitric acid1 and hence1 that the direct absorption of nitrogen1 if it occur at all1 must do so to a very small extent1 the addition of a very minute quantity of the former substance immediately produces an active vegetation and rapid increase in size of the plants4 ,among the most striking proofs of this are the experiments of ,wolff1 made by growing barley and vetches in a soil calcined so as to destroy organic matters1 and then mixed with small quantities of different compounds of ammonia4 ,he found that when the produce from the calcined soil was represented by #ajj1 that from the different ammoniacal salts was-- ,barley4 ,vetches4 ,muriate of ,ammonia #beg4b #agf4d ,carbonate of ,ammonia #abc4f #agc4h ,sulphate of ,ammonia #bjc4f #abe4b ,these experiments not only prove that ammonia can be absorbed1 but they also indirectly confirm the statement already made1 that humus is not necessary2 for in some instances the produce was higher than that obtained from the uncalcined soil with the same manures1 although it contained four per cent of humus4 ,on such experiments ,liebig rests his opinion that ammonia is the exclusive source of the nitrogen of plants1 and although he has recently admitted that it may be replaced by nitric acid1 it is obvious that he considers this a rare and exceptional occurrence4 ,the evidence1 however1 for the absorption of nitric acid appears to rest on as good grounds as that of ammonia1 for experience has shown that nitrate of soda acts powerfully as a manure1 and its effect must be due to the nitric acid1 and not to the soda1 for the other compounds of that alkali have no such effect4 ,wolff has illustrated this point by a series of experiments on the sunflower1 of which we shall quote one4 ,he took two seeds of that plant1 and sowed them on the #ajth ,may1 in a soil composed of calcined sand1 mixed with a small quantity of the ash of plants1 and added at intervals during the progress of the experiment1 a quantity of nitrate of potash1 amounting in all to #ag4ac grains4 ,the plants were watered with distilled water1 containing carbonic acid in solution1 and the pot in which they grew was protected from rain and dew by a glass cover4 ,on the #aith ,august one of the plants had attained a height of above #bh inches1 and had nine fine leaves and a flower-bud2 the other was about #bj inches high1 and had ten leaves4 ,on the #bb;d ,august1 one of the plants having been accidentally injured1 the experiment was terminated4 ,the plants1 which contained #ajc4af grains of dry matter1 were then carefully analysed1 and the quantity of nitrogen contained in the soil after the experiment and in the seed was determined4 ,grains4 ,nitrogen in the dry plants #a4gcg remaining in the soil #j4fig #b4dcd in the nitrate of potash #b4cgj in the seeds #j4jbi #b4cii ------ ,difference #j4jce ,hence1 the nitrogen contained in the plants must1 in this instance1 have been obtained entirely from the nitrate of potash1 for the quantity contained in it and in the seeds is exactly equal to that in the plants and the soil1 the difference of #j4jc grains being so small that it may be safely attributed to the errors inseparable from such experiments4 ,for the sake of comparison1 an exactly similar experiment was made on two seeds grown without nitrate of potash1 and in this instance1 after an equally long period of growth1 the largest plant had only attained a height of #g4e inches1 and had three small pale and imperfectly developed leaves4 ,they contained only #j4jcc grains of nitrogen1 while the seeds contained #j4jcb--;indicating that1 under these circumstances1 there was no increase in the quantity of that element4 ,but1 independently of these experimental results1 it may be inferred from general considerations1 that nitric acid must be one of the sources from which plants derive their nitrogen4 ,it has been already stated1 that the humus contained in the soil consists of the remains of decayed plants1 and there is every reason to suppose that the primeval soil contained no organic matters1 and that the first generation of plants must have derived the whole of their nitrogen from1 the atmosphere4 ,if1 therefore1 it be assumed that ammonia is the only source of the nitrogen of plants1 it would follow1 that as that substance cannot be produced by the direct union of its elements1 the quantity of ammonia in the air could only remain undiminished in the event of the whole of the nitrogen of decaying plants returning into that form4 ,but this is certainly not the case1 for every time a vegetable substance is burned1 part of its nitrogen is liberated in the free state1 and in certain conditions of putrefaction1 nitric acid is produced4 ,now1 if ammonia be the only form in which nitrogen is absorbed1 there must be a gradual diminution of the quantity contained in the air2 and further1 there must either be some continuous source of supply by which its quantity is maintained1 or there must be some other substance capable of affording nitrogen in a form fitted for the maintenance of plant life4 ,as regards the first alternative1 it must be stated that we know of no source other than the decomposition of plants from which ammonia can be derived1 and we are therefore compelled to adopt the second alternative1 and to admit that there must be some other source of nitrogen1 and it cannot be doubted1 from what has been already stated1 that it is from nitric acid only that it can be obtained4 ,it must be admitted1 then1 that carbonic acid1 ammonia1 nitric acid1 and water1 are the great organic foods of plants4 ,but while they have afforded to them an inexhaustible supply of the last1 the quantity of the other three available for food are limited1 and insufficient to sustain their life for a prolonged period4 ,it has been shown by ,chevandrier1 that an acre of land under beech wood accumulates annually about #afej lb4 of carbon4 ,now1 the column of air resting upon an acre of land contains only about #ae1ejj lb4 of carbon1 and the soil may be estimated to contain #a per cent41 or #bb1djj lb4 per acre1 and the whole of this carbon would therefore be removed1 both from the air and the soil1 in the course of little more than #bc years4 ,but it is a familiar fact1 that plants continue to grow with undiminished luxuriance year after year in the same soil1 and they do so because neither their carbon nor their nitrogen are permanently absorbed2 they are there only for a period1 and when the plant has finished its functions1 and dies1 they sooner or later return into their original state4 ,either the plant decays1 in which case its carbon and nitrogen pass more or less rapidly into their original state1 or it becomes the food of animals1 and by the processes of respiration and secretion1 the same change is indirectly effected4 ,in this way a sort of balance is sustained2 the carbon1 which at one moment is absorbed by the plant1 passes in the next into the tissues of the animal1 only to be again expired in that state in which it is fitted to commence again its round of changes4 ,but while there is thus a continuous circulation of these constituents through both plants and animals1 there are various changes which tend to liberate in the free state a certain quantity both of the carbon and nitrogen of plants1 and these being thus removed from the sphere of organic life1 there would be a gradual diminution in the amount of vegetation at the earth's surface1 unless this loss were counterbalanced by some corresponding source of gain4 ,in regard to carbonic acid the most important source is volcanic action1 but the loss of nitrogen1 which is far more important and considerable1 is restored by the direct combination of its elements4 ,the formation of nitric acid during thunder storms has been long familiar2 but it would appear from the recent experiments of ,cloeez1 which1 should they be confirmed by farther enquiry1 will be of much importance1 that this compound is also produced without electrical action when air is passed over certain porous substances1 saturated with alkaline and earthy compounds4 ,fragments of calcined brick and pumice stone were saturated with solution of carbonate of potash1 with carbonates of lime and magnesia and other mixtures1 and a current of air freed from nitric acid and ammonia passed over them for a long period1 at the end of which notable quantities of nitric acid were detected4 ,source of the ,inorganic ,constituents of ,plants4--,the inorganic constituents of plants being all fixed substances1 it is sufficiently obvious that they can only be obtained from the soil1 which1 as we shall afterwards see1 contains all of them in greater or less abundance1 and has always been admitted to be the only substance capable of supplying them4 ,the older chemists and physiologists1 however1 attributed no importance to these substances1 and from the small quantities in which they are found in plants1 imagined that they were there merely accidental impurities absorbed from the soil along with the humus1 which was at that time considered to be their organic food4 ,this opinion1 sufficiently disproved by the constant occurrence of the same substances in nearly the same proportions1 in the ash of each individual plant1 has been further refuted by the experiments of ,prince ,salm ,horstmar1 who has established their importance to vegetation1 by experiments upon oats grown on artificial soils1 in each of which one inorganic constituent was omitted4 ,he found that1 without silica1 the grain vegetated1 but remained small1 pale in colour1 and so weak as to be incapable of supporting itself2 without lime1 it died when it had produced its second leaf2 without potash and soda1 it grew only to the height of three inches2 without magnesia1 it was weak and incapable of supporting itself2 without phosphoric acid1 weak but upright2 and without sulphuric acid1 though normal in form1 the plant was feeble1 and produced no fruit4 ,manner in which the ,constituents of ,plants are absorbed4--,having treated of the sources of the elements of plants1 it is necessary to direct attention to the mode in which they enter their system4 ,water4--,the absorption of water by plants takes place in great abundance1 and is connected with many of the most important phenomena of vegetation4 ,it is principally absorbed by the roots1 and passes into the tissues of the plant1 where a part of it is decomposed1 and goes to the formation of certain of its organic compounds2 while by far the larger quantity1 in place of remaining in it1 is again exhaled by the leaves4 ,the extent to which this takes place is very large4 ,hales found that a sunflower exhaled in twelve hours about #a lb4 #e oz4 of water1 but this quantity was liable to considerable variation1 being greater in dry1 and less in wet weather1 and much diminished during the night4 ,saussure made similar experiments1 and observed that the quantity of water exhaled by a sunflower amounted to about #bbj lb4 in four months4 ,the exhalation of plants has recently been examined with great accuracy by ,lawes4 ,his experiments were made by planting single plants of wheat1 barley1 beans1 peas1 and clover1 in large glass jars capable of holding about #db lb4 of soil1 and covered with glass plates1 furnished with a hole in the centre for the passage of the stem of the plant4 ,water was supplied to the soil at certain intervals1 and the jars were carefully weighed4 ,the result of the experiments1 continued during a period of #agb days1 is given in the following table1 which shows the total quantity of water exhaled in grains3-- ,wheat #aac1ebg ,barley #abj1jbe ,beans #aab1bca ,peas #aji1jhb ,clover1 cut #bhth ,june #ee1jic ,it further appears1 that the exhalation is not uniform1 but increases during the active growth of the plant1 and diminishes again when that period is passed4 ,these variations are shown by the subjoined tables1 of which the first gives the total exhalation1 and the second the average daily loss of water during certain periods4 ,,table ,i4--,showing the ,number of ,grains of ,water given off by the ,plants during stated divisional ,periods of their ,growth4 ---------------------------------------- ---------------------------- ,description#i ,days4 #ca ,days4#bg ,days4#cd ,days4#cj ,days4#ad ,days4 #bg ,days4 ---------------------------------------- ----------------- of ,plant4 ,from ,from ,from ,from ,from ,from ,from ,mar4 #ai,mar4 #bh ,apr4 #bh ,may #be ,june #bh ,july #bh ,aug4 #aa to to to to to to to ,mar4 #bh4;,apr4 #bh4,may #be4 ,june #bh4;,july #bh4;,aug4 #aa4 ,sept4 #g4 ---------------------------------------- ---------------------------- ,wheat #abi #abfh #d1che #dj1jcj #df1jfj #ae1dbj #fbce ,barley #abi #ahfg #ab1jbi #cg1dhj #de1jfj #ag1jdf #fdad ,beans #hh #ahed #d1hdf #cj1aaj #eh1iej #ab1fbf #cfeg ,pease #aja #accb #b1hgc #cf1gae #fb1ghj #e1bha 444 ,clover #djj #afde #b1idh #ej1ajj 444 444 444 ---------------------------------------- ---------------------------- ,,table ,,ii4--,showing the average daily ,loss of ,water 7in ,grains7 by the ,plants1 within several stated divisional ,periods of their ,growth4 ---------------------------------------- ---------------------------- ,description#i ,days4 #ca ,days4#bg ,days4#cd ,days4#cj ,days4#ad ,days4#bg ,days4 ---------------------------------------- ---------------- of ,plant4 ,from ,from ,from ,from ,from ,from ,from ,mar4 #ai ,mar4 #bh ,apr4 #bh ,may #be ,june #bh ,july #bh ,aug4 #aa to to to to to to to ,mar4 #bh4;,apr4 #bh4,may #be4 ,june #bh4;,july #bh4;,aug4 #aa4,sept4 #g4 ---------------------------------------- ---------------------------- ,wheat #ad4c #dj4i #afb4d #aagg4d #aece4c #aaja4d #bcj4i ,barley #ad4c #fj4b #dde4e #aajb4c #aejb4j #abag4f #bcg4e ,beans #i4g #ei4h #agi4e #hhe4f #aife4j #ija4h #ace4d ,peas #aa4b #db4i #ajf4d #ajgi4h #bjib4g #cgg4b 444 ,clover #dd4d #ec4j #aji4b #adgc4e 444 444 444 ---------------------------------------- ---------------------------- ,similar experiments were made with the same plants in soils to which certain manures had been added1 and with results generally similar4 ,calculating from these experiments1 we are led to the apparently anomalous conclusion that the quantity of water exhaled by the plants growing on an acre of land greatly exceeds the annual fall of rain2 although it is obvious that of all the rain which falls1 only a small proportion can be absorbed by the plants growing on the soil1 for a large quantity is carried off by the rivers1 and never reaches their roots4 ,it has been calculated1 for instance1 that the ,thames carries off in this way at least one-third of the annual rain that falls in the district watered by it1 and the ,rhine nearly four-fifths4 ,of course this large exhalation must depend on the repeated absorption of the same quantity of water1 which1 after being exhaled1 is again deposited on the soil in the form of dew1 and passes repeatedly through the plant4 ,this constant percolation of water is of immense importance to the plant1 as it forms the channel through which some of its other constituents are carried to it4 ,carbonic ,acid4--,while the larger part of the water which a plant requires is absorbed by its roots1 the reverse is the case with carbonic acid4 ,a certain proportion no doubt is carried up through the roots by the water1 which always contains a quantity of that gas in solution1 but by far the larger proportion is directly absorbed from the air by the leaves4 ,a simple experiment of ,boussingault's illustrates this absorption very strikingly4 ,he took a large glass globe having three apertures1 through one of which he introduced the branch of a vine1 with twenty leaves on it4 ,with one of the side apertures a tube was connected1 by means of which the air could be drawn slowly through the globe1 and into an apparatus in which its carbonic acid was accurately determined4 ,he found1 in this way1 that while the air which entered the globe contained #j4jjjd of carbonic acid1 that which escaped contained only #j4jjja1 so that three-fourths of the carbonic acid had been absorbed4 ,ammonia and ,nitric ,acid4--,little is known regarding the mode in which these substances enter the plant4 ,it is usually supposed that they are entirely absorbed by the roots1 and no doubt the greater proportion is taken up in this way1 but it is very probable that they may also be absorbed by the leaves1 at least the addition of ammonia to the air in which plants are grown1 materially accelerates vegetation4 ,it is probable1 however1 that the rain carries down the ammonia to the roots1 and there is no doubt that that derived from the decomposition of the nitrogenous matters in the soil is so absorbed4 ,inorganic ,constituents4--,the inorganic constituents of course are entirely absorbed by the roots2 and it is as a solvent for them that the large quantity of water continually passing through the plants is so important4 ,they exist in the soil in particular states of combination1 in which they are scarcely soluble in water4 ,but their solubility is increased by the presence of carbonic acid contained in the water1 and which causes it to dissolve1 to some extent1 substances otherwise insoluble4 ,it is in this way that lime1 which occurs in the soil principally as the insoluble carbonate1 is dissolved and absorbed4 ,and phosphate of lime is also taken up by water containing carbonic acid1 or even common salt in solution4 ,the amount of solubility produced by these substances is extremely small2 but it is sufficient for the purpose of supplying to the plant as much of its mineral constituents as are required1 for the quantity of water which1 as we have already seen1 passes through a plant is very large when compared with the amount of inorganic matters absorbed4 ,it has been shown by ,lawes and ,gilbert1 that about #bjjj grains of water pass through a plant for every grain of mineral matter fixed in it1 so that there is no difficulty in understanding how the absorption takes place4 ,it is worthy of notice1 however1 that the absorption of the elements of plants takes place even though they may not be in solution in the soil1 the roots apparently possessing the power of directly acting on and dissolving insoluble matters2 but a distinction must be drawn between this and the view entertained by ,jethro ,tull1 who supposed that they might be absorbed in the solid state1 provided they were reduced to a state of sufficient comminution4 ,it is now no longer doubted that1 whatever action the roots may exert1 the constituents of the plant must be in solution before they can pass into it--experiment having distinctly shown that the spongioles or apertures through which this absorption takes place are too minute to admit even the smallest solid particle4 ,,chapter ,,ii4 ,,the ,,proximate ,,constituents ,,of ,,plants4 ,the substances absorbed by the plant1 which are of simple composition1 and contain only two elements1 are elaborated within it1 and converted into the many complicated compounds of which its mass is composed4 ,some of these1 as1 for example1 the colouring matters of madder and indigo1 the narcotic principle of the poppy1 c41 are confined to a single species1 or small group of plants1 while others are found in all plants1 and form the main bulk of their tissues4 ,the latter are the only substances which claim notice in a treatise like the present4 ,they have been divided into three great classes1 of widely different properties1 composition1 and functions4 #ast4 ,the ,saccharine and ,amylaceous ,constituents4--,these substances are compounds of carbon1 hydrogen1 and oxygen1 and all possess a certain degree of similarity in composition1 the quantities of hydrogen and oxygen they contain being always in the proportion required to form water1 so that they may be considered as compounds of carbon and water2 not that it can be asserted that they actually do contain water1 as such1 for of that there is no evidence1 but only that its elements are present in the proportion to form it4 ,cellulose4--,this substance forms the fundamental part of all plants4 ,it is the principal constituent of woody fibre1 and is found in a state of purity in the fibre of cotton and flax1 and in the pith of plants2 but in wood it is generally contaminated with another substance1 which has received the name incrusting matter1 because it is deposited in and around the cells of which the plant is in part composed4 ,cellulose is insoluble in all menstrua1 but1 when boiled for a long time with sulphuric acid1 is converted into a substance called dextrine4 ,cellulose consists of-- ,from pith of ,elder-tree4 ,spongioles of roots4 ,carbon #dc4cg #dc4jj ,hydrogen #f4jd #f4ah ,oxygen #ej4ei #ej4hb ------- ------- #ajj4jj #ajj4jj ,it is represented chemically by the formula1 ,c#bd;,h#ba,o#ba1 which shows it to be a compound of #bd atoms of carbon with #ba of hydrogen and #ba of oxygen4 ,incrusting matter4--,large quantities of this substance enter into the composition of all plants4 ,of its chemical nature little is known1 as it cannot be obtained separate from cellulose1 but it is analogous to that substance in its composition1 and probably contains hydrogen and oxygen in the proportion to form water4 ,starch4--,starch is one of the most abundant constituents of plants1 and is found in most seeds1 as those of the cereals and the leguminous plants2 in the tubers of the potatoe1 the bulbs of tulips1 c4 c4 ,it is obtained by placing a quantity of wheat flour in a bag1 and kneading it under a gentle stream of water4 ,when the water is allowed to stand1 it deposits the starch as a fine white powder1 which1 when examined by the microscope1 is found to be composed of minute grains1 formed of concentric layers deposited on one another4 ,these grains vary considerably in size and structure in different plants2 but in the same plant they are generally so much alike as to admit of their recognition by a practised observer4 ,they were formerly believed to be composed of an external coating of a substance insoluble in water1 and containing in their interior a soluble kernel2 but this opinion has been refuted1 and distinct evidence been brought to show that the exterior and interior of the globules are identical in chemical properties4 ,starch is insoluble in cold water1 but by boiling1 it dissolves1 forming a thick paste4 ,by long continued boiling with water containing a small quantity of acid1 it is completely dissolved and converted into dextrine1 and eventually into sugar4 ,the same change is produced by the action of fermenting substances1 such as the extract of malt2 when heated in the dry state to a temperature of about #cij ,fahr41 it becomes soluble in cold water4 ,it is distinguished by giving a brilliant blue compound with iodine4 ,starch contains-- ,carbon #dd4dg ,hydrogen #f4bh ,oxygen #di4be ------ #ajj4jj and its composition is represented by the formula ,c#ab;,h#aj,o#aj1 so that it differs but little from cellulose in composition1 although its chemical functions in the plant are extremely different4 ,it is connected with some of the most important changes which occur in the growing plants1 and by a series of remarkable transformations is converted into sugar and other important compounds4 ,lichen ,starch is found in most species of lichens1 and is distinguished from common starch by producing a green colour with iodine4 ,its composition is the same as that of ordinary starch4 ,inuline4--,the species of starch to which this name is given is characterised by its dissolving in boiling water1 and giving a white pulverulent deposit in cooling4 ,it is found in the tuber of the dahlia1 in the dandelion1 and some other plants4 ,its composition is identical with that of cellulose1 and its formula is ,c#bd;,h#ba,o#ba4 ,gum is excreted from various plants as a thick fluid1 which dries up into transparent masses4 ,its composition is identical with that of starch4 ,it dissolves readily in cold water1 and is converted into sugar by long continued boiling with acids4 ,its properties are best marked in gum arabic1 which is obtained from various species of acacia2 that from other plants differs to some extent1 although its chemical composition is the same4 ,dextrine4--,when starch is exposed to a heat of about #djj deg41 or when treated with sulphuric acid1 or with a substance extracted from malt called diastase1 it is converted into dextrine4 ,it may also be obtained from cellulose by a similar treatment4 ,the dextrine so obtained has the same composition as the starch from which it is produced1 but its properties more nearly resemble those of gum4 ,it plays a very important part in the process of germination1 and may be converted into sugar on the one hand1 and apparently also into starch on the other4 ,sugar4--,under this name are included four or five distinct substances1 of which the most important are1 cane sugar1 grape sugar1 and the uncrystallisable sugar found in many plants4 ,cane ,sugar4--,this variety of sugar1 as its name implies1 is found most abundantly in the sugar cane1 but it occurs also in the maple1 beet-root1 and various species of palms1 from all of which it is extracted on the large scale4 ,it is extremely soluble in water1 and can be obtained in large transparent prismatic crystals1 as in common sugar-candy4 ,it swells up1 and is converted into a brown substance called caramel1 when heated1 and by contact with fermenting substances1 yields alcohol and carbonic acid4 ,it contains-- ,carbon #db4bb ,hydrogen #f4fj ,oxygen #ea4ah ------ #ajj4jj and its chemical formula is ,c#ab;,h#aa,o#aa4 ,grape ,sugar is met with in the grape1 and most other fruits1 as well as in honey4 ,it is produced artificially when starch is boiled for a long time with sulphuric acid1 or treated with a large quantity of diastase4 ,it is less soluble in water than cane sugar1 and crystallises in small round grains4 ,its composition1 when dried at #bhd deg41 is-- ,carbon #dj4jj ,hydrogen #f4ff ,oxygen #ec4cd ------ #ajj4jj and its formula is ,c#ab;,h#ab,o#ab2 but when crystallised it contains two equivalents of water1 and is then represented by the formula ,c#ab;,h#ab,o#ab #b;,h#b,o4 ,the uncrystallisable sugar of plants is closely allied to grape sugar1 and1 so far as at present known1 has the same composition1 although1 from the difficulty of obtaining it quite free from crystallised sugar1 this is still uncertain4 ,mucilage is the name applied to the substance existing in linseed1 and in many other seeds1 and which communicates to them the property of swelling up and becoming gelatinous when treated with water4 ,it is found in a state of considerable purity in gum tragacanth and some other gums4 ,its composition is not known with absolute certainty1 but it is either ,c#bd;,h#ai,o#ai1 or ,c#ab;,h#aj,o#aj2 and in the latter case it must be identical with starch and gum4 ,it will be observed that all the substances belonging to this class are very closely related in chemical composition1 some of them1 as starch and gum1 though easily distinguished by their properties1 being identical in constitution1 while others only differ in the quantity of water1 or of its elements which they contain4 ,in fact1 they may all be considered as compounds of carbon and water1 and their relations are1 perhaps1 more distinctly seen when their formulae are written so as to show this1 as is done in the following table1 in the second column of which those containing twelve equivalents of carbon are doubled1 so as to make them comparable with cellulose3-- ,water4 ,grape sugar1 ,c#ab;,h#ab,o#ab ,c#bd;,h#bd,o#bd ,c#bd #bd ,cane sugar1 ,c#ab;,h#aa,o#aa ,c#bd;,h#bb,o#bb ,c#bd #bb ,cellulose1 ,c#bd;,h#ba,o#ba ,c#bd;,h#ba,o#ba ,c#bd #ba ,inuline1 ,c#bd;,h#ba,o#ba ,c#bd;,h#ba,o#ba ,c#bd #ba ,starch1 ,c#ab;,h#aj,o#aj ,c#bd;,h#bj,o#bj ,c#bd #bj ,dextrine1 ,c#ab;,h#aj,o#aj ,c#bd;,h#bj,o#bj ,c#bd #bj ,gum1 ,c#ab;,h#aj,o#aj ,c#bd;,h#bj,o#bj ,c#bd #bj ,mucilage1 ,c#ab;,h#aj,o#aj ,c#bd;,h#bj,o#bj ,c#bd #bj ,the relation between these substances being so close1 it is not difficult to understand how one may be converted into another by the addition or subtraction of water4 ,thus1 cellulose has only to absorb an equivalent of water to become grape sugar1 or to lose an equivalent in order to be converted into starch1 and we shall afterwards see that such changes do actually occur in the plant during the process of germination4 ,pectine and ,pectic ,acid4--,these substances are met with in many fruits and roots1 as1 for instance1 in the apple1 the carrot1 and the turnip4 ,they differ from the starch group in containing more oxygen than is required to form water along with their hydrogen2 but their exact composition is still uncertain1 and they undergo numerous changes during the ripening of the fruit4 #b;d4 ,oily or ,fatty ,matters4--,the oily constituents of plants form a rather extensive group of substances all closely allied1 but distinguished by minor differences in properties and constitution4 ,some of them are very widely distributed throughout the vegetable kingdom1 but others are almost peculiar to individual plants4 ,they are all compounds of carbon1 hydrogen1 and oxygen1 and are at once distinguished from the preceding class1 by containing much less oxygen than is required to form water with their hydrogen4 ,the principal constituents of the fatty matters and oils of plants are three substances1 called stearine1 margarine1 and oleine1 the two former solids1 the latter a fluid2 and they rarely1 if ever1 occur alone1 but are mixed together in variable proportions1 and the fluidity of the oils is due principally to the quantity of the last which they contain4 ,if olive oil be exposed to cold1 it is seen to become partially solid2 and if it be then pressed1 a fluid flows out1 and a crystalline substance remains2 the former is oleine1 though not absolutely pure1 and the latter margarine4 ,the perfect separation of these substances involves a variety of troublesome chemical processes2 and when it has been effected1 it is found that each of them is a compound of a peculiar acid1 with another substance having a sweet taste1 and which has received the name of glycerine1 or the sweet principle of oil4 ,glycerine1 as it exists in the fats1 appears to be a compound of ,c#c;,h#b,o1 and its properties are the same from whatever source it is obtained4 ,the acids separated from it are known by the names of margaric1 stearic1 and oleic acids4 ,margaric ,acid is best obtained pure by boiling olive oil with an alkali until it is saponified1 and decomposing the soap with an acid1 expressing the margaric acid1 which separates1 and crystallising it from alcohol4 ,it is a white crystalline fusible solid1 insoluble in water1 but soluble in alcohol and in solutions of the alkalies4 ,its composition is-- ,carbon #ge4ef ,hydrogen #ab4ei ,oxygen #aa4he ------ #ajj4jj and its formula ,c#cd;,h#cd,o#d4 ,stearic ,acid4--,although this acid exists in many plants1 it is most conveniently extracted from lard4 ,it is a crystalline solid less fusible than margaric acid1 but closely resembling it in its other properties4 ,its formula is ,c#cf;,h#cf,o#d4 ,oleic ,acid4--,under this name two different substances appear to be included4 ,it has been applied generally to the fluid acids of all oils1 while it would appear that the drying and non-drying oils actually contain substances of different composition4 ,the acid extracted from olive oil appears to have the formula ,c#cf;,h#cd,o#d1 while that from linseed oil is ,c#df;,h#ch,o#f1 but this is still doubtful4 ,other fatty acids have been detected in palm oil1 cocoa-nut oil1 c4 c41 which so closely resemble margaric and stearic acids as to be easily confounded with them4 ,though presenting many points of interest1 it is unnecessary to describe them in detail here4 ,wax is a substance closely allied to the oils4 ,it consists of two substances1 cerine and myricine1 which are separated from one another by boiling alcohol1 in which the former is more soluble4 ,they are extremely complex in composition1 the former consisting principally of an acid similar to the fatty acids1 called cerotic acid1 and containing ,c#ed;,h#ed,o#d4 ,the latter has the formula ,c#ib;,h#ib,o#d4 ,the wax found in the leaves of the lilac and other plants appears to consist of myricine1 while that extracted from the sugar-cane is said to be different1 and to have the formula ,c#dh;,h#ej,o#b4 ,it is probable that other plants contain different sorts of wax1 but their investigation is still so incomplete1 that nothing definite can be said regarding them4 ,wax and fats appear to be produced in the plant from starch and sugar2 at least it is unquestionable that the bee is capable of producing the former from sugar1 and we shall afterwards see that a similar change is most probably produced in the plant4 ,the fatty matters contained in animals are identical with those of plants4 #c;d4 ,nitrogenous or ,albuminous ,constituents of ,plants and ,animals4--,the nitrogenous constituents of plants and animals are so closely allied1 both in properties and composition1 that they may be most advantageously considered together4 ,albumen4--,vegetable albumen is found dissolved in the juices of most plants1 and is abundant in that of the potato1 the turnip1 and wheat4 ,in these juices it exists in a soluble state1 but when its solution is heated to about #aej deg41 it coagulates into a flocky insoluble substance4 ,it is also thrown down by acids and alcohol4 ,coagulated albumen is soluble in alkalies and in nitric acid4 ,animal albumen exists in the white of eggs1 the serum of blood1 and the juice of flesh2 and from all these sources is scarcely distinguishable in its properties from vegetable albumen4 ,it is a substance of very complicated composition1 and chemists are not agreed as to the formula by which its constitution is to be expressed1 a difficulty which occurs also with most of the other nitrogenous compounds4 ,the results of the analyses of albumen from different sources are however quite identical1 as may be seen from those subjoined-- ,from ,from ,from ,from ,wheat4 ,potatoes4 ,blood4 ,white of ,egg4 ,carbon #ec4g #ec4a #ec4d #ec4j ,hydrogen #g4a #g4b #g4j #g4a ,nitrogen #ae4f 444 #ae4e #ae4f ,oxygen 444 #bb4a #bb4i ,sulphur #bc4f #j4ig #a4f #a4a ,phosphorus 444 #j4d #j4c ----- ----- ----- #ajj4j #ajj4j #ajj4j ,closely allied to vegetable albumen is the substance known by the name of glutin1 which is obtained by boiling the gluten of wheat with alcohol4 ,it appears to be a sort of coagulated albumen1 with which its composition completely agrees4 ,vegetable ,fibrine4--,if a quantity of wheat flour be tied up in a piece of cloth1 and kneaded for some time under water1 the starch it contains is gradually washed out1 and there remains a quantity of a glutinous substance called gluten4 ,when this is boiled with alcohol1 the glutin above referred to is extracted1 and vegetable fibrine is left4 ,it dissolves in dilute potash1 and on the addition of acetic acid is deposited in a pure state4 ,treated with hydrochloric acid1 diluted with ten times its weight of water1 it swells up into a jelly-like mass4 ,when boiled or preserved for a long time under water1 it cannot be distinguished from coagulated albumen4 ,animal ,fibrine exists in the blood and the muscles1 and agrees in all its characters and composition with vegetable fibrine1 as is shown by the subjoined analyses-- ,wheat ,flour4 ,blood4 ,flesh4 ,carbon #ec4a #eb4e #ec4c ,hydrogen #g4j #f4i #g4a ,nitrogen #ae4f #ae4e #ae4c ,oxygen #bc4b #bd4j #bc4a ,sulphur #a4a #a4a #a4b ----- ----- ----- #ajj4j #ajj4j #ajj4j ,caseine4--,vegetable caseine exists abundantly in most plants1 especially in the seeds1 and remains in the juice after albumen has been precipitated by heat1 from which it may be separated in flocks by the addition of an acid4 ,it has been obtained for chemical examination1 principally from peas and beans1 and from the almond and oats4 ,when prepared from the pea it has been called legumine1 from almonds emulsine1 and from oats avenine2 but they are all three identical in their properties1 although formerly believed to be different1 and distinguished by these names4 ,vegetable caseine is best obtained by treating peas or beans with hot water1 and straining the fluid4 ,on standing1 the starch held in suspension is deposited1 and the caseine is retained in solution in the alkaline fluid2 by the addition of an acid it is precipitated as a thick curd4 ,caseine is insoluble in water1 but dissolves readily in alkalies2 its solution is not coagulated by heat1 but1 on evaporation1 becomes covered with a thin pellicle1 which is renewed as often as it is removed4 ,animal ,caseine is the principal constituent of milk1 and is obtained by the cautious addition of an acid to skimmed milk1 by which it is precipitated as a thick white curd4 ,it is also obtained by the use of rennet1 and the process of curding milk is simply the coagulation of its caseine4 ,it is soluble in alkalies1 and precipitated from its solution by acids1 and in all other respects agrees with vegetable caseine4 ,the composition of animal caseine has been well ascertained1 but considerable doubt still exists as to that of vegetable caseine1 owing to the difficulty of obtaining it absolutely pure4 ,the analyses of different chemists give rather discordant results1 but we have given those which appear most trustworthy-- ,from ,peas4 ,carbon #ej4f #ej4g ,hydrogen #f4h #f4f ,nitrogen #af4e #ae4h ,oxygen #be4f #bc4h ,sulphur #j4e #j4h ,phosphorus 444 #b4c ----- ----- #ajj4j #ajj4j ,other results differ considerably from these1 and some observers have even obtained as much as eighteen per cent of nitrogen and fifty-three of carbon4 ,the composition of animal caseine differs from this principally in the amount of carbon4 ,its composition is-- ,carbon #ec4f ,hydrogen #g4a ,nitrogen #ae4h ,oxygen #bb4e ,sulphur #a4j ----- #ajj4j ,the most cursory examination of these analytical numbers is sufficient to show that a very close relation subsists between the different substances just described4 ,indeed1 with the exception of vegetable caseine1 they may be said all to present the same composition2 and1 as already mentioned1 there are analyses of it which would class it completely with the others4 ,while1 however1 the quantities of carbon1 hydrogen1 nitrogen1 and oxygen are the same1 differences exist in the sulphur and phosphorus they contain1 and which1 though very small in quantity1 are indubitably essential to them4 ,much importance has been attributed to these constituents by various chemists1 and especially by ,mulder1 who has endeavoured to make out that all the albuminous substances are compounds of a substance to which he has given the name of proteine1 with different quantities of sulphur and phosphorus4 ,the composition of proteine1 according to his newest experiments1 is-- ,carbon #ed4j ,hydrogen #g4a ,nitrogen #af4j ,oxygen #ba4d ,sulphur #a4e ----- #ajj4j and is exactly the same from whatever albuminous compound it is obtained4 ,although the importance of proteine is probably not so great as ,mulder supposed1 it affords an important illustration of the close similarity of the different substances from which it is obtained1 the more especially as there is every reason to believe that the different albuminous compounds are capable of changing into one another1 just as starch and sugar are mutually convertible2 and the possibility of this change throws much light on many of the phenomena of nutrition in plants and animals4 ,indeed1 it would seem probable that these compounds are formed from their elements by plants only1 and are merely assimilated by animals to produce the nitrogenous constituents they contain4 ,diastase is the name applied to a substance existing in malt1 and obtained by macerating that substance with cold water1 and adding a quantity of alcohol to the fluid1 when the diastase is immediately precipitated in white flocks4 ,it is produced during the malting process1 and is not found in the unmalted barley4 ,its chemical composition is unknown1 but it is nitrogenous1 and is believed to be produced by the decomposition of gluten4 ,if a very small quantity of diastase be mixed with starch suspended in hot water1 the starch is found gradually to dissolve1 and to pass first into the state of dextrine1 then into that of sugar4 ,the change thus effected takes place also in a precisely similar manner in the plant1 diastase being produced during the process of germination of all seeds and tubers1 for the purpose of effecting this change1 and to fulfil other functions less understood1 but no doubt equally important4 ,diastase is found in the seeds only during the period when the starch they contain is passing into sugar2 as soon as that change has taken place1 its function is ended1 and it disappears4 ,,chapter ,,iii4 ,,the ,,changes ,,which ,,take ,,place ,,in ,,the ,,food ,,of ,,plants ,,during ,,their ,,growth4 ,the simple compounds which the plant absorbs from the atmosphere and soil are elaborated within its system1 and converted into the various complex substances of which its tissues are composed1 by a series of changes1 the details of which are still in some respects imperfectly known1 although their general nature is sufficiently well understood4 ,they may be best rendered intelligible by reference1 in the first instance1 to the changes occurring during germination1 when the young plant is nourished by a supply of food stored up in the seed1 in sufficient quantity to maintain its existence until the organs by which it is afterwards to draw its nutriment from the air and soil are sufficiently developed to serve that purpose4 ,changes occurring during ,germination4--,when a seed is placed in the soil under favourable circumstances1 it becomes the seat of an important and remarkable series of chemical changes1 which result in the production of the young plant4 ,experiment and observation have shown that heat1 moisture1 and air1 are necessary to the production of these changes1 and though probably not absolutely essential1 the absence of light is favourable in the early stages4 ,the temperature required for germination varies greatly in different seeds1 some germinating readily at a few degrees above the freezing point1 and others requiring a tolerably high temperature4 ,the rapidity with which it takes place appears to increase with the temperature2 but this is true only within very narrow limits1 for beyond a certain point heat is injurious1 and when it exceeds #abj deg4 or #acj deg4 ,fahrenheit1 entirely prevents the process4 ,the presence of oxygen is also essential1 for it has been shown that if seeds are placed in a soil exposed to an atmosphere deprived of that element1 or if they be buried so deep that the air does not reach them1 they may lie without change for an unlimited period2 but so soon as they are exposed to the air1 germination immediately commences4 ,illustrations of this fact are frequently observed where earth from a considerable depth has been thrown up to the surface1 when it often becomes covered with plants not usually seen in the neighbourhood1 which have sprung from buried seeds4 ,when all the necessary conditions for germination are fulfilled1 the seed absorbs moisture1 swells up1 and sends out a shoot which rises to the surface1 and a radicle which descends--the one destined to develop the leaves1 the other the roots1 by which the plant is afterwards to derive its nutriment from the air and the soil4 ,but until these organs are properly developed1 the plant is dependent on the matters contained in the seed itself4 ,these substances are mostly insoluble1 but are brought into solution by the atmospheric oxygen acting upon the gluten1 and converting it into a soluble substance called diastase1 which in its turn reacts upon the starch1 converting it first into dextrine1 and then into cellulose1 and the latter is finally deposited in the form of organised cells1 and produces the first little shoot of the plant4 ,at the first moment of germination1 the oxygen absorbed appears simply to oxidize the constituents of the seed1 but this condition exists only for a very limited period1 and is soon followed by the evolution of carbonic acid1 water being at the same time formed from the organic constituents of the seed1 which gradually diminishes in weight4 ,the amount of this diminution is different with different plants1 but always considerable4 ,boussingault found that the loss of dry substance in the pea amounted in #bf days to #eb per cent1 and in wheat to #eg per cent in #ea days4 ,against this1 of course1 is to be put the weight of the young plant produced2 but this is never sufficient to counterbalance the diminished weight of the seed1 for ,saussure found that a horse bean and the plant produced from it weighed1 after #af days1 less by #bi per cent than the seed before germination4 ,the same phenomenon is observed in the process of malting1 which is in fact the artificial germination of barley1 the malt produced always weighing considerably less than the grain from which it was obtained4 ,it was believed by ,saussure1 and the older investigators1 that the carbonic acid evolved was entirely produced from starch and sugar2 and as these substances may be viewed as compounds of carbon and water1 the change was very simply explained by supposing that the carbon was oxidised and converted into carbonic acid and its water eliminated4 ,but this hypothesis is incapable of explaining all the phenomena observed2 for woody fibre1 which is one of the chief constituents of the young plant1 contains more carbon than the starch and sugar from which it must have been produced1 and we are1 therefore1 forced to admit that the action must be more complicated4 ,there is every reason to believe that the nitrogenous constituents of the seed are most abundantly oxidized1 for they are remarkably prone to change2 but the action of the air is not confined to them1 and it appears most probable that all the substances take part in the decomposition1 and the process of germination may1 in some respects1 be compared to decay or putrefaction1 which1 like it1 is attended by the absorption of oxygen and evolution of carbonic acid2 but while in the latter case the residual substances remain in a useless state1 in the former they at once become part of a new organism4 ,changes occurring during the ,after-growth of the ,plant4--,when the plant has developed its roots and leaves1 and exhausted the store of materials laid up for it in the seed1 it begins to derive its subsistence from the surrounding air1 and to absorb carbonic acid1 water1 ammonia1 and nitric acid1 and to decompose and convert them into the different constituents of its tissues4 ,these changes take place slowly at first1 and more rapidly as the organs fitted for the elaboration of its food are developed4 ,the roots and the leaves are equally active in performing this duty1 the former absorbing the mineral matters along with the carbonic acid1 ammonia1 nitric acid1 and moisture in the soil1 or the manure added to it2 the latter gathering the gaseous substances existing in the air4 ,each of these undergoes a series of changes claiming our consideration4 ,decomposition of ,carbonic ,acid4--,carbonic acid1 which appears to be absorbed with equal readiness by the roots1 leaves1 and stems1 undergoes immediate decomposition1 its carbon being retained1 and its oxygen1 in whole or in part1 evolved into the air4 ,this decomposition occurs only under the action of the sun's rays1 and has been found to be proportionate to the amount of light to which the plant is exposed4 ,it takes place only in the green parts of plants1 for though the roots absorb carbonic acid1 they cannot decompose it1 or evolve oxygen2 and the coloured parts1 the flowers1 fruits1 etc41 have an entirely opposite effect1 absorbing oxygen and giving off carbonic acid4 ,the absorption of carbonic acid and escape of oxygen has been proved by numerous direct experiments by ,saussure and others1 in which both atmospheric air and artificial mixtures containing an increased quantity of carbonic acid have been employed4 ,saussure allowed seven plants of periwinkle 7,vinca minor7 to vegetate in an atmosphere containing #g4e per cent of carbonic acid for six days1 during each of which the apparatus was exposed for six hours to the sun's rays4 ,the air was analysed both before and after the experiment1 and the results obtained were-- ,volume ,carbonic of the air4 ,nitrogen4 ,oxygen4 ,acid4 ,before the experiment1 #egdf #daii #aaaf #dca ,after #egdf #dcch #adjh #j ---- ---- ---- ---- ,difference1 #j #aci #bib -#dca ,in this experiment the whole of the carbonic acid1 amounting to #dca volumes1 was absorbed1 but only #bib volumes of oxygen were given off4 ,had the carbonic acid been entirely decomposed1 and all its oxygen eliminated1 its volume would have been equal to that of the acid1 or #dca1 so that in this instance #aci volumes of the oxygen of the carbonic acid have been retained to form part of the tissues of the plant4 ,on the other hand1 the nitrogen is found to be increased after the experiment4 ,it might be supposed that the nitrogen evolved had been derived from the decomposition of the nitrogenous constituents of the plant1 but this cannot be the true explanation1 because in this particular case it greatly exceeded the whole nitrogen contained in the plants experimented on4 ,its source is not well understood1 but ,boussingault supposes it to have existed in the interstices of the plant1 and to have escaped during the course of the experiment4 ,saussure found that the oak1 the horse-chesnut1 and other plants1 absorb oxygen and give off carbonic acid in less volumes than the oxygen1 while the house-leek and the cactus absorb oxygen without evolving carbonic acid4 ,the absorption and decomposition of carbonic acid takes place only during the day1 and matters are entirely reversed during the night1 when oxygen is absorbed and carbonic acid eliminated from all parts of the plants4 ,although the action occurring during the night is the reverse of that which takes place during the day1 it is in no degree to be attributed to a re-oxidation of the carbon which had been deposited in the tissues of the plant4 ,it appears1 on the contrary1 to be a purely mechanical1 and not a chemical process4 ,during the night the sap continues to circulate through the vessels of the plant1 and moisture1 carrying with it carbonic acid in solution1 is absorbed by the roots2 but when it reaches the leaves1 where the sun's light would have caused its decomposition during the day1 it is again exhaled unchanged4 ,the oxygen absorbed during the night must1 however1 take part in some chemical processes1 for if it were merely mechanical1 the absorption would not be confined to that gas alone1 but would be participated in by the other constituents of the air4 ,moreover1 the amount of absorption varies greatly in different plants--being scarcely appreciable in some1 and very abundant in others4 ,plants containing volatile oils1 which are readily converted into resins by the action of oxygen1 or those containing tannin or other readily oxidizable substances1 take up the largest quantity4 ,this is remarkably illustrated by an experiment in which the leaves of the ,agave americana1 after twenty-four hours' exposure in the dark1 were found to have absorbed only #j4c of their volume of oxygen1 while those of the fir1 in which volatile oil is abundant1 had taken up twice1 and those of the oak1 containing tannin1 eighteen times as much oxygen4 ,in the flowers1 both by day and night1 there is a constant absorption of oxygen1 and evolution of carbonic acid4 ,in fact1 an active oxidation is going on1 attended by the evolution of heat1 which1 in the ,arum maculatum and some other plants1 is so great as to raise the temperature of the flower #aj deg4 or #ab deg4 above that of the surrounding air4 ,decomposition of ,water in the ,plant4--,in addition to the function which water performs in the plant1 as the solvent of the different substances which form its nutriment1 and hence as the medium through which they pass into its organs1 it serves also as a direct food1 undergoing decomposition1 and yielding hydrogen to the organic substances4 ,its constituents1 along with those of the carbonic acid absorbed1 undergo a variety of transformations1 and form the principal part of the non-nitrogenous constituents4 ,it has been already observed that starch1 sugar1 and the other allied substances1 may be considered as compounds of carbon with water2 and they might be supposed to owe their origin to the carbonic acid losing the whole of its oxygen1 and direct combination then ensuing between the residual carbon and a certain proportion of water2 but this would imply that the latter substance undergoes no decomposition1 and though undoubtedly the simplest view of the case1 it is by no means the most probable4 ,it is much more likely that the carbonic acid is only partially decomposed1 half its oxygen being separated1 and replaced by hydrogen1 produced by the decomposition of a certain quantity of water into its elements4 ,thus1 for instance1 sugar may be produced from twelve equivalents of carbonic acid and twelve equivalents of water1 twenty-four equivalents of oxygen being eliminated1 as thus represented3 #ab equivalents of carbonic acid1 ,c#ab,o#ab,o#ab #ab water1 ,h#ab,o#ab #a sugar1 and #bd of ox4 ,c#ab;,h#ab,o#ab ,o#bd ,it must not be supposed that we are in a condition to assert that sugar is really produced in the manner here shown1 the illustration being given merely for the purpose of pointing out how it may be supposed to occur1 and on a similar principle it is possible to explain the formation of most other vegetable compounds2 and this subject has been very fully discussed by the late ,dr4 ,gregory1 in his ,handbook of ,organic ,chemistry4 ,that water must be decomposed1 is evident from the fact1 established by analysis1 that the hydrogen of the plant generally exceeds the quantity required to form water with its oxygen1 so that this excess at least must be produced by the decomposition of water4 ,the hydrogen of the volatile oils1 many of which contain no oxygen1 and that of the fats1 which contain only a small quantity1 must manifestly be obtained in a similar manner4 ,decomposition of ,ammonia4--,the nitrogenous or albuminous compounds of vegetables must necessarily obtain their nitrogen from the decomposition either of ammonia or nitric acid1 experiment having distinctly shown that they are incapable of absorbing it in the free state from the atmosphere4 ,it has been clearly ascertained that the albuminous substances do not contain ammonia1 and it is hence apparent that a complete decomposition of that substance must take place in the plant4 ,no doubt carbonic acid and water take part with it in these changes1 which must be of a very complex character1 and in the present state of our knowledge it seems hopeless to attempt any explanation of them4 ,decomposition of ,nitric ,acid4--,chemists are not entirely at one as to whether nitric acid is directly absorbed by the plant1 or is first converted into ammonia4 ,but there are certain facts connected with the chemistry of the soil1 to be afterwards referred to1 which seem to us to leave no doubt that it may be directly absorbed2 and in that case it must be decomposed1 its oxygen being eliminated1 and the nitrogen taking part with carbon and hydrogen in the formation of the organic compounds4 ,it must be clearly understood that while such changes as those described manifestly must take place1 the explanations of them which have been attempted by various chemists are not to be accepted as determinately established facts2 they are at present no more than hypothetical views which have been expressed chiefly with the intention of presenting some definite idea to the mind1 and are unsupported by absolute proof2 they are only inferences drawn from the general bearings of known facts1 and not facts themselves4 ,although1 therefore1 they are to be received with caution1 they have advantages in so far as they present the matter to us in a somewhat more tangible form than the vague general statements which are all that could otherwise be made4 ,,chapter ,,iv4 ,,the ,,inorganic ,,constituents ,,of ,,plants4 ,when treating of the general constituents of plants1 it has been already stated that the older chemists and vegetable physiologists1 misled by the small quantity of ash found in them1 entertained the opinion that mineral matters were purely fortuitous components of vegetables1 and were present merely because they had been dissolved and absorbed along with the humus1 which was then supposed to enter the roots in solution1 and to form the chief food of the plant4 ,this supposition1 which could only be sustained at a time when analysis was imperfect1 has been long since disproved and abandoned1 and it has been distinctly shown by repeated experiment that not only are these inorganic substances necessary to the plant1 but that every one of them1 however small its quantity1 must be present if it is to grow luxuriantly and arrive at a healthy maturity4 ,the experiments of ,prince ,salm ,horstmar1 before alluded to1 have established beyond a doubt1 that while a seed may germinate1 and even grow1 to a certain extent1 in absence of one or more of the constituents of its ash1 it remains sickly and stunted1 and is incapable of producing either flower or seed4 ,of late years the analysis of the ash of different plants has formed the subject of a large number of laborious investigations1 by which our knowledge of this subject has been greatly extended4 ,from these it appears that the quantity of ash contained in each plant or part of a plant is tolerably uniform1 differing only within comparatively narrow limits1 and that there is a special proportion belonging to each individual organ of the plant4 ,this fact may be best rendered obvious by the subjoined table1 showing the quantity of ash contained in a hundred parts of the different substances dried at #bab deg44 ,most of these numbers are the mean of several experiments3-- ,table showing the quantity of inorganic matters in #ajj parts of different plants dried at #bab deg44 ,,seeds4 ,wheat #a4ig ,barley #b4dh ,oats 7with husk7 #c4hj ,oats 7without husk7 #b4jf ,rye #b4jj ,millet #c4fj ,rice #j4cg ,maize #a4bj ,peas #b4hh ,beans #c4bb ,kidney ,beans #d4ji ,lentils #b4ea ,tares #b4fj ,buckwheat #b4ac ,linseed #d4dj ,hemp seed #e4fj ,rape seed #d4ce ,indian ,rape-seed,a #d4jf ,sunflower #c4bf ,cotton seed #e4ic ,guinea ,corn #a4ii ,gold of ,pleasure #d4aj ,white ,mustard #d4ae ,black ,mustard #d4ca ,poppy #f4ef ,niger seed 7,guizotia oleifera7 #g4jj ,earth nut #c4hh ,sweet ,almond #d4ij ,horse-chesnut #b4ha ,grape #b4gf ,clover #f4ai ,turnip #c4ih ,carrot #aj4jc ,sainfoin #e4bg ,italian ,ryegrass #f4ia ,mangold-,wurzel #f4eh ,,straws ,,and ,,stems4 ,wheat #d4ed ,barley #d4ii ,oat #g4bd ,winter ,rye #e4ae ,summer ,rye #e4gh ,millet #h4cb ,maize #c4fj ,pea #d4ha ,bean #f4ei ,tares #f4jj ,lentil #e4ch ,buckwheat #d4ej ,hops #d4db ,flax straw #d4be ,hemp #d4ad ,gold of ,pleasure #f4je ,rape #d4da ,potato #ad4ij ,jerusalem ,artichoke #d4dj ,,entire ,,plant4 ,potato #ag4gj ,spurry #aj4jf ,red ,clover #h4gi ,white ,clover #h4gb ,yellow ,clover #h4ef ,crimson ,clover 7,t4 incarnatum7 #aj4ha ,cow ,grass 7,t4 medium7 #aa4ca ,sainfoin #f4ea ,ryegrass #f4db ,meadow ,foxtail 7,alopecurus pratensis7 #g4ha ,sweet-scented ,vernal ,grass 7,anthoxanthum odoratum7 #f4cb ,downy ,oat ,grass 7,avena pubescens7 #e4bb ,bromus erectus #e4ba ,bromus mollis #e4hb ,cynosurus cristatus #f4ch ,dactylis glomeratus #e4ca ,festuca duriuscula #e4db ,holcus lanatus #f4cg ,hordeum pratense #e4fg ,lolium perenne #g4ed ,poa annua #b4hc ,poa pratensis #e4id ,poa trivialis #h4cc ,phleum pratense #e4bi ,plantago lanceolata #h4fh ,poterium ,sanguisorba #g4ig ,yarrow #ac4de ,rape ,kale #h4jj ,cow ,cabbage #aj4jj ,asparagus #f4dj ,parsley #a4aj ,furze #c4aa ,chamomile 7,anthemis arvensis7 #i4ff ,wild ,chamomile 7,matricaria ,chamomilla7 #i4aj ,corn ,cockle 7,agrostemma ,githago7 #ac4bj ,corn ,blue ,bottle 7,centaurea ,cyanus7 #g4cb ,foxglove #aj4hi ,hemlock 7,conium maculatum7 #ab4hj ,sweet ,rush 7,acorus ,calamus7 #f4ij ,common ,reed 7,arundo ,phragmites7 #a4dd ,celandine 7,chelidonium majus7 #f4he ,equisetum fluviatile #bc4fj ,equisetum hyemale #aa4hj arvense #ac4hj linosum #ae4ej ,fucus nodosus #ai4jc ,fucus vesiculosus #bg4fc ,laminaria digitata #ci4fh ,,leaves4 ,turnip #i4cg ,beet #bj4cj ,kohl-rabi #ah4ed ,carrot #aj4ie ,jerusalem ,artichoke #bh4cj ,hemp #bb4jj ,hop #ag4be ,tobacco #bb4fb ,spinach #ai4gf ,chicory #ae4fg ,poplar #bc4jj ,red ,beech #f4jj ,white ,beech #aj4ea ,oak #i4hj ,elm #af4cc ,horse-chesnut #i4jh ,maple #bh4je ,ash #ad4gf ,fir #b4ca ,acacia #ah4bj ,olive #f4de ,orange #ac4gc ,potato #ae4aj ,tussac ,grass #g4ae ,,roots ,,and ,,tubers4 ,potato #d4af ,jerusalem ,artichoke #e4ch ,turnip #ac4fd ,beet #h4bg ,kohl-rabi #f4jh ,rutabaga #g4cd ,carrot #e4hj ,belgian ,white ,carrot #f4bb ,mangold-,wurzel #h4gh ,parsnip #e4eb ,radish #g4ce ,chicory #e4ba ,madder #h4cc ,,woods4 ,beech #j4ch ,apple #a4bi ,cherry #j4bh ,birch #a4jj ,oak #b4ej ,walnut #a4eg ,lime #e4jj ,horse-chesnut #a4je ,olive #j4eh ,mahogany #j4ha ,vine #b4eg ,larch #j4cb ,fir #j4ad ,scotch ,fir #j4ag ,filbert #j4ej ,chesnut #c4ej ,poplar #j4hj ,hazel #j4ej ,orange #b4gd ,vine #b4eg ,,barks4 ,beech #f4fb ,cherry #aj4cg ,fir #a4gi ,oak #f4jj ,horse-chesnut #g4he ,filbert #f4bj ,cork #a4ab ,,fruits4 ,plum #j4dj ,cherry #j4dc ,strawberry #j4da ,pear #j4da ,apple #j4bg ,chesnut #j4ii ,cucumber #j4fc ,vegetable ,marrow #e4aj ,on examining this table it may be observed that1 notwithstanding the very great variety in the proportion of ash in different plants1 some general relations may be traced4 ,a certain similarity may be observed between those belonging to the same natural family1 the seeds of all the cereal grains1 for instance1 containing in round numbers two per cent of inorganic matters4 ,leguminous seeds 7peas and beans7 contain about three per cent1 while in rape-seed1 linseed1 and the other oily seeds1 it reaches four per cent4 ,in the stems and straws less uniformity exists1 but with the exception of a few extreme cases1 the quantity of ash in general approaches pretty closely to five per cent4 ,still more diversified results are obtained from the entire plants2 but this diversity is probably much more apparent than real1 and must be1 in part at least1 dependent on the proportion existing between the stem and leaves1 for the leaves are peculiarly rich in ash1 and a leafy plant must necessarily yield a higher total percentage of ash1 although1 if stems and leaves were separately examined1 they might not show so conspicuous a difference4 ,the leaves surpass all other parts of plants1 in the proportion of inorganic constituents they contain1 the table showing that in some instances1 as in the maple and ,jerusalem artichoke1 they exceed one-fourth of the whole weight of the dry matter4 ,in other leaves1 and more especially in those of the coniferae1 the proportion is much smaller4 ,taking the average of all the analyses hitherto made1 it appears that leaves contain about thirteen per cent of ash1 but the variations on either side are so large that little value is to be attached to it except as an indication of the general abundance of mineral matters4 ,in roots and tubers the variations are less1 and all1 except the potato and the turnip1 contain about seven per cent of ash4 ,the smallest proportion of mineral matter is found in wood4 ,in one case only does the proportion reach five per cent1 while the average scarcely exceeds one1 and in the fir the quantity amounts to no more than one six-hundredth of the dry matter4 ,in the bark the quantity is much larger1 and may be stated at seven per cent4 ,the general proportion of ash found in different parts of plants is given in round numbers in the subjoined table3-- ,wood #a ,seeds #c ,stems and straws #e ,roots and tubers #g ,bark #g ,leaves #ac ,the differences in the quantity of ash contained in different parts of plants are obviously intended to serve a useful purpose1 and it is interesting to observe that the wood which is destined to remain for a long period1 sometimes for several centuries1 a part of the plant1 contains the smallest proportion1 and it is not improbable that what it does contain is really due1 not to the actual woody matter itself1 but to the sap which permeates its vessels4 ,by this arrangement but a small proportion of these important mineral matters1 which the soil supplies in very limited quantity1 is locked up within the plant1 and those which are absorbed1 after circulating through it1 and fulfilling their allotted functions1 are accumulated in the leaves1 and annually returned to the soil4 ,the different proportions of mineral matters contained in the individual organs of plants is most strikingly illustrated when parallel experiments are made on the same species2 but the number of instances in which a sufficiently extensive series of analyses has been made to show this1 is comparatively limited1 and is confined to the oat1 the orange-tree1 and the horse chesnut--each of which has formed the subject of a very elaborate investigation4 ,the following table gives the results obtained on the oat3-- ---------------------------------------- ------------------------ ,hopetoun ,hopetoun ,potato ,black ,sandy ,oats1 ,oats1 ,oats1 ,oats1 ,oats1 ,mean4 ,north- ,fife- ,north- ,edin- ,fife- umberland4 shire4 umberland4 burgh4 shire4 ---------------------------------------- ------------------------ ,grain #b4ad #a4ha #b4bb #b4aa #a4gf #b4jj ,husk #f4dg #f4jc #f4ii #h4bd #f4jc #f4ge ,chaff #af4ec #ag4bc #ae4ei #ai4ai #ah4ig #af4jf ,leaves #h4dd #g4ai #ad4ei #aj4bi #ae4ib #aj4hh ,upper part of straw #d4ie #e4dd #i4bb #h4be #aa4j #g4gg ,middle part of straw #f4aa #e4bc #g4da #f4ec #i4ja #f4ff ,lower part of straw #e4cc #e4ah #i4gf #g4aa #g4cj #f4ic ---------------------------------------- ------------------------ ,the specimens of oats on which these analyses were made were from different districts of country1 grown on soils of different quality1 and were1 further1 of different varieties2 and yet they show1 on the whole1 a remarkable similarity in the proportion of ash in each part1 and indicate that there is a normal quantity belonging to it4 ,such a series of analyses also affords the most convincing proof that the inorganic matters cannot be fortuitous1 and merely absorbed from the soil along with their organic food1 as the old chemists supposed1 because1 in that case1 they ought to be uniformly distributed throughout the entire plant1 and not accumulated in particular proportions in each individual organ4 ,not only does the proportion of ash vary in the different parts of a plant1 but even in the same part it is greatly influenced by its period of growth4 ,the laws which regulate these variations are very imperfectly known1 but in general it is observed that during the period of active growth the quantity of ash is largest4 ,thus1 it has been found that in early spring the wood of the young shoots of the horse-chesnut contains #i4i per cent of ash4 ,in autumn this has diminished to #c4d1 and the last year's twigs contain only #a4a per cent1 while in the old wood the quantity does not exceed #j4e4 ,saussure has also observed that the quantity of ash diminishes in certain plants when the seed has ripened4 ,thus1 he found that the percentages of ash1 before flowering1 and after seeding1 were as follows3-- ,before flowering4 ,with ripe seed4 ,sunflower #ad4g #i4c ,wheat #g4i #c4c ,maize #ab4b #d4f ,on the other hand1 the quantity of ash in the leaves of trees increases considerably in autumn1 as shown by this table3-- ,,per-,,centage ,,of ,,ash ,,in ,may4 ,september4 ,oak leaves #e4c #e4e ,poplar #f4f #i4c ,hazel #f4a #g4j ,horse-chesnut #g4b #h4f ,in general1 the proportion of ash appears to increase as the plant reaches maturity1 and this is particularly seen in the oat1 of which very complete analyses have been made at different periods of its growth3-- ,proportion of ,ash in different parts of the ,oat at different periods of its growth4 ---------------------------------------- ------------ ,grain ,date4 ,stalks4 ,leaves4 ,chaff4 with husk4 ---------------------------------------- ------------ #b;d ,july #g4hc #aa4ce 444 #d4ia #ith ,july #g4hj #ab4bj 444 #d4cf #afth ,july #g4id #ab4fa #f4jj #c4ch #bc;d ,july #g4ii #af4de #i4aa #c4fb #cjth ,july #g4de #af4dd #ab4bh #d4bb #eth ,august #g4fc #af4je #ac4ge #d4ca #acth ,august #f4fb #bj4dg #ah4fh #d4jg #bjth ,august #f4ff #ba4ad #ba4jg #c4fd #bgth ,august #g4ga #bb4ac #bb4df #c4ea #c;d ,september #h4ce #bj4ij #bg4dg #c4fe ---------------------------------------- ------------ ,the increase is here principally confined to the leaves and chaff1 while the stalks1 which owe their strength to a considerable extent to the inorganic matters they contain1 are equally supplied at all periods of their growth4 ,in the grain only is there a diminution1 but this is apparent and not real1 and is due to the fact that the determination of the quantity of ash1 as made on the grain with its husk1 and the former1 which contains only a small quantity of mineral matters1 increases much more rapidly in weight than the latter1 when it approaches the period of ripening1 and it is accordingly during the last three weeks of its growth that this diminution becomes apparent4 ,the nature of the soil has also a very important influence on the proportion of mineral matters1 and of this an interesting illustration is given in the following table1 which shows the quantities found in the grain and straw of the same variety of the pea grown on fourteen different soils3-- ------------------- ,seed4 ,straw4 ------------------- #a #b4cj #b #c4be #c4dc #c #d4bg #c4fb #d #c4dj #c4ci #e #b4ii #c4ij #f #c4ai #f4hj #g #b4ec #c4ij #h #b4bg #f4ei #i #b4fi #c4di #aj #a4fa #c4ia #aa #c4aa #e4bh #ab #c4cd #g4eg #ac #b4gh #c4gf #ad #c4ja #c4ch ------------------- ,although those differences are very large1 especially in the straw1 and must be attributed to the soil1 it has hitherto been found impossible to ascertain the nature of the relation subsisting between it and the crops it yields2 indeed1 it must obviously be dependent on very complicated questions1 which cannot at present be solved1 for it may be observed that the increase in the grain does not occur simultaneously with that in the straw1 and in several cases a large proportion of ash in the former is associated with an unusually small amount in the latter4 ,a priori1 it might be expected that those soils which are especially rich in the more important constituents of the ash should yield a produce containing more than the average quantity1 but this is very far from being an invariable occurrence1 and not unfrequently the very reverse is the case4 ,in some instances the variations may be traced to the soil1 as in the following analyses of the fruit of the horse-chesnut1 grown on an ordinary forest soil1 and on a rich soil1 produced by the disintegration of porphyritic rock1 in which the latter yields a much larger quantity of ash3-- ,kernel of seed4 ,green husk4 ,brown husk4 ,forest soil #b4bf #d4ec #a4gj ,porphyry soil #c4cf #g4bi #b4bj ,in the majority of instances we fail to establish any connection between the nature of the soil and the plants it yields1 chiefly because we are still very deficient in analyses of those grown on uncultivated soils2 and on cultivated land it is impossible to draw conclusions1 because the nature of the manure exerts an influence quite as great1 if not greater1 than that of the soil itself4 ,the relative proportion in which the different mineral matters enter into the composition of the ash varies within very wide limits1 as will be apparent from the following table1 containing a selection of the best analyses of our common cultivated and a few uncultivated plants4 ,table of the ,composition of the ,ash of different ,plants in #ajj ,parts4 ,note4--,alumina and oxide of manganese occur so rarely1 that separate columns have not been introduced for them1 but their quantity is stated in notes at the end of the table4 ---------------------------------------- ------------------------------- ,potash4 ,soda4 ,chloride ,chloride ,lime4 ,magnesia4 of of ,potassium4 ,sodium4 ---------------------------------------- ------------------------------- ,wheat1 grain #cj4jb #c4hb 444 444 #a4ae #ac4ci straw #ag4ih #b4dg 444 444 #g4db #a4id chaff #i4ad #a4gi 444 444 #a4hh #a4bg ,barley1 grain #ba4ad 444 #e4fe #a4ja #a4fe #g4bf straw #aa4bb 444 444 #b4ad #e4gi #b4gj ,oats1 grain,b #bj4fc 444 #a4jc 444 #aj4bh #g4hb straw #ai4df #a4ic #b4ga #d4bg #g4ja #c4gi chaff,c #f4cc #c4ic 444 #j4bd #a4ie #j4ch ,rye1 grain #cc4hc #j4ci 444 444 #b4fa #ab4ha straw #ag4bj 444 #j4cj #j4fj #i4aj #b4dj ,maize1 grain #bh4cg #a4gd 444 trace #j4eg #ac4fj stalks and leaves #ce4bf 444 444 #b4bi #aj4ec #e4eb ,rice1 grain #bj4ba #b4di 444 444 #g4ah #d4bf ,buckwheat1 straw #ca4ga 444 #g4db #d4ee #ae4ga #a4ff ,peas 7gray71 seed #da4gj 444 #c4hb #a4bd #d4gh #e4gh straw #ba4cj #d4bb 444 444 #cg4ag #g4ag ,beans 7common field71 grain #ea4gb #j4ed 444 444 #e4bj #f4ij straw #cb4he #b4gg 444 #aa4ed #ai4he #b4ec ,tare1 straw #cb4hb 444 #c4bg #d4jc #bj4gh #e4ca straw #ca4gb 444 #g4da #d4ee #ae4ga #a4ff ---------------------------------------- ------------------------------- ---------------------------------------- -------------------------------- ,oxide ,phosphoric ,sulphuric ,carbonic ,silica4 of ,acid4 ,acid4 ,acid4 ,iron4 ---------------------------------------- -------------------------------- ,wheat1 grain #j4ia #df4gi 444 444 #c4hi straw #j4de #b4ge #c4ji 444 #fc4hi chaff #j4cg #d4ca 444 444 #ha4bb ,barley1 grain #b4ac #bh4ec #a4ia 444 #cj4fh straw #a4cf #g4bj #a4ji 444 #fh4ej ,oats1 grain #c4he #ej4dd 444 444 #d4dj straw #a4di #e4jg #c4ce #a4cf #di4ef chaff #a4eh #a4jd #i4fa 444 #gb4he ,rye1 grain #a4jd #ci4ib #j4ag 444 #i4bb straw #a4dj #c4hj #j4hj 444 #fd4ej ,maize1 grain #j4dg #ec4fi 444 444 #a4ee stalks and leaves #b4bh #h4ji #e4af #b4hg #bg4ih ,rice1 grain #b4ab #fb4bc 444 444 #a4cg ,buckwheat1 straw 444 #aj4cd #d4fg #bj4cg #c4eg ,peas 7gray71 seed #j4ah #cf4ej #d4dg #j4hb #j4fh straw #a4jg #d4fe #h4fh #ab4dh #c4bc ,beans 7common field71 grain 444 #bh4gb #c4je #c4db #j4db straw #j4fa #j4di #a4dj #be4cb #b4fa ,tare1 straw #j4fe #aj4ei #b4eb #ah4gc #a4bh straw 444 #aj4cd #d4fg #bj4cg #c4eg ---------------------------------------- -------------------------------- ---------------------------------------- ------------------------------- ,potash4 ,soda4 ,chloride ,chloride ,lime4 ,magnesia4 of of ,potassium4 ,sodium4 ---------------------------------------- ------------------------------- ,flax1 seed #cd4ag #a4fi 444 #j4cf #h4dj #ac4aa straw #ba4ec #c4fh 444 #i4ba #ba4bj #d4bj ,rape1 seed,d #af4cc #j4cd 444 #j4if #h4cj #h4hj straw,e #af4fc #aj4eg 444 #b4ec #ba4ea #b4ib ,spurry #bf4ab #a4ad 444 #h4ij #ad4df #h4hh ,chicory root #cd4fd 444 #h4ib #b4ih 444 444 ,red clover #be4fj 444 #i4jh #f4jb #ba4eg #h4dg ,cow grass1 ,trifolium medium #bb4gh 444 #ab4ci #a4hf #bd4db #h4hf ,yellow clover #bg4dh 444 #aa4gb #h4af #ag4bf #h4ci ,alsike clover #bi4gb 444 #f4bi #a4je #bf4hc #d4ja ,lucerne #bg4ef 444 #aa4fd #a4ia #bj4fj #e4bb ,anthoxanthum odoratum #cb4jc 444 #g4jc #d4ij #i4ba #b4ec ,alopecurus pratensis #cg4jc 444 #i4ej 444 #c4ij #a4bh ,avena pubescens #ca4ba 444 #d4je #e4ff #d4gb #c4ag ,bromus erectus #bj4cc 444 #aj4fc #a4ch #aj4ch #d4ii ,bromus mollis #cj4ji #j4cc 444 #c4aa #f4fd #b4fj ,cynosurus cristatus #bd4ii 444 #aa4fj 444 #aj4af #b4dc ,dactylis glomerata #bi4eb 444 #ag4hf #c4ji #e4hb #b4bb ,festuca duriuscula #ca4hd 444 #h4ag #j4fb #aj4ca #b4hc ,holcus lanatus #cd4hc 444 #c4ia #f4ff #h4ca #c4da ,lolium perenne #bd4fg 444 #ac4hj #g4be #i4fd #b4he ,annual ryegrass #bh4ii #j4hg 444 #e4aa #f4hb #b4ei ,poa annua #da4hf 444 #j4dg #c4ce #aa4fi #b4dd ,poa pratensis #ca4ag 444 #aa4be #a4ca #e4fc #b4ga ,poa trivialis #bi4dj 444 #f4ij 444 #h4hj #c4bb ,phleum pratense #ca4ji 444 #j4gj #c4bd #ad4id #e4cj ,plantago lanceolata #cc4bf 444 #d4ec #h4hj #ai4ja #c4ea ,poterium ,sanguisorba #cj4bf 444 #c4bg #a4ce #bd4hb #d4ba ,achillea ,millefolia #cj4cg 444 #bj4di #c4fc #ac4dj #c4ja ,potato1 tuber #dc4ah #j4ji 444 #g4ib #a4hj #c4ag stem #ci4ec #c4ie 444 #bj4dc #ad4he #d4aj leaves #ag4bg 444 #d4ie #aa4cg #bg4fi #g4gh ,jerusalem ,artichoke #ee4hi 444 #d4hh 444 #c4cd #a4cj stem #ch4dj #j4fi 444 #d4fh #bj4ca #a4ia leaves #f4ha #c4gb 444 #a4hb #dj4ae #a4ie ,turnip1 seed #ba4ia #a4bc 444 444 #ag4dj #h4gd bulb #bc4gj #ad4ge 444 #g4je #aa4hb #c4bh leaves #aa4ef #ab4dc 444 #ab4da #bh4di #b4fb ,mangold ,wurzel1 root #ba4fh #c4ac 444 #di4ea #a4ij #a4gi leaves #h4cd #ab4ba 444 #cg4ff #h4gb #i4hd ,carrot1 root #db4gc #ab4aa 444 444 #e4fd #b4bi leaves #ag4aj #d4he 444 #c4fb #bd4je #j4hi ,kohl-rabi1 bulb #cf4bg #b4hd 444 #aa4ij #aj4bj #b4cf leaves #i4ca 444 #e4ii #f4ff #cj4ca #c4fb ,cow cabbage1 head #dj4hf #b4dc 444 444 #ae4ja #b4ci stalk #dj4ic #d4je 444 #b4jh #aj4fa #c4he ,poppy seed #i4aj 444 #g4ae #a4id #ce4cf #i4di leaves #cf4cg 444 #b4ej #b4ea #cj4bd #f4dg ,mustard seed 7white7 #be4gh #j4cc 444 444 #ai4aj #e4ij ,radish root #ba4af 444 #a4bi #g4jg #h4gh #c4ec ,tobacco leaves #cf4cg 444 #b4ej #b4ea #cj4bd #f4dg ,fucus nodosus,f #bj4jc #d4eh 444 #bd4cc #i4fj #f4fe ,fucus vesiculosus,g #bj4ge #f4ji 444 #bd4ha #h4ib #e4hc ,laminaria digitata,h #ab4af 444 #b4cj #ai4cd #d4fb #aj4id ---------------------------------------- ------------------------------- ---------------------------------------- ------------------------------ ,oxide ,phosphoric ,sulphuric ,carbonic ,silica4 of ,acid4 ,acid4 ,acid4 ,iron4 ---------------------------------------- ------------------------------ ,flax1 seed #j4ej #ch4ed #a4ef #j4bb #a4de straw #e4eh #g4ec #c4ci #ae4ge #g4ib ,rape1 seed #a4gi #ca4ij #e4ch #e4dd #ai4ih straw #a4cj #d4fh #c4ij #bc4jd #aa4hj ,spurry 444 #aj4bj #a4gi #bg4ch #a4ad ,chicory root 444 444 444 444 444 ,red clover #a4bf #d4ji #b4if #ah4je #a4ie ,cow grass1 ,trifolium medium #a4ji #d4id #b4ff #bj4af #a4ab ,yellow clover #a4dj 444 #d4hb #d4ca #a4gf ,alsike clover #j4ga #e4fd #c4be #bj4gd #a4gc ,lucerne #b4bc #f4dg #d4hj #ae4id #b4fc ,anthoxanthum odoratum #a4ah #aj4ji #c4ci #a4bf #bh4ce ,alopecurus pratensis #j4dg #f4be #b4af #j4fe #ch4ge ,avena pubescens #j4gb #aj4hb #c4cg 444 #cf4bh ,bromus erectus #j4bf #g4ec #e4df #j4ee #ch4dh ,bromus mollis #j4bh #i4fb #d4ia #i4jg #cc4cd ,cynosurus cristatus #j4ah #g4bd #c4bj 444 #dj4aa ,dactylis glomerata #j4ei #h4fj #c4eb #b4ji #bf4fe ,festuca duriuscula #j4gh #ab4jg #c4de #a4ch #bh4ec ,holcus lanatus #j4ca #h4jb #d4da #a4hb #bh4ca ,lolium perenne #j4ba #h4gc #e4bj #j4di #bg4ac ,annual ryegrass #j4bh #aj4jg #c4de 444 #da4gi ,poa annua #a4eg #i4aa #aj4ah #c4bi #af4jc ,poa pratensis #j4bh #aj4jb #d4bf #j4dj #cb4ic ,poa trivialis #j4bi #i4ac #d4dg #j4bi #cg4ej ,phleum pratense #j4bg #aa4bi #d4hf #d4jb #ca4ji ,plantago lanceolata #j4ij #g4jh #f4aa #ad4dj #b4cg ,poterium ,sanguisorba #j4hf #g4ha #d4hd #ba4gb #j4hc ,achillea ,millefolia #j4ba #g4ac #b4dd #i4cf #i4ib ,potato1 tuber #j4dd #h4fa #ae4bd #ah4bi #a4id stem #a4cd #f4fh #f4ef 444 #b4ef leaves #d4ej #ac4fj #f4cg 444 #f4dg ,jerusalem ,artichoke #j4de #af4ii #c4gg #aa4hj #a4eb stem #j4hh #b4ig #c4bc #be4dj #a4ea leaves #a4ad #f4fa #b4ba #bd4ca #ag4be ,turnip1 seed #a4ie #dj4ag #g4aj #j4hb #j4fg bulb #j4dg #i4ca #af4ac #aj4gd #b4fi leaves #c4jb #d4he #aj4cf #f4ah #h4jd ,mangold ,wurzel1 root #j4eb #a4fe #c4ad #ae4bc #a4dj leaves #a4df #e4hi #f4ed #f4ib #b4ce ,carrot1 root #j4ea #ab4ca #d4bf #ah4jj #a4aa leaves #c4dc #f4ba #e4jh #bc4ae #aa4fa ,kohl-rabi1 bulb #j4ch #ac4de #aa4dc #aj4bd #j4hc leaves #e4ej #i4dc #aj4fc #h4ig #i4eg ,cow cabbage1 head #j4gg #ab4ec #g4bg #af4fh #a4ff stalk #j4da #ai4eg #aa4aa #f4cc #a4jd ,poppy seed #j4da #ca4ch #a4ib 444 #c4bd leaves #b4ad #c4bh #e4ji 444 #aa4dj ,mustard seed 7white7 #j4ci #dd4ig #b4ai 444 #a4ca ,radish root #a4ai #da4ji #g4ga 444 #h4ag ,tobacco leaves #b4ah #c4bd #e4ji 444 #aa4dj ,fucus nodosus #j4bf #a4ga #ba4ig #f4ci #j4ch ,fucus vesiculosus #j4ce #b4ad #bh4ja #b4bj #j4fg ,laminaria digitata #j4de #a4ge #g4bf #ae4bc #a4bj ---------------------------------------- ------------------------------ ,a simple inspection of this table leads to various interesting conclusions4 ,it is particularly to be observed that some of the constituents of the ash are not invariably present1 and two at least--namely1 alumina and manganese--are found so rarely as to justify the inference that they are not indispensable4 ,of the other substances1 iodine is restricted exclusively to sea-plants1 but to them it appears to be essential4 ,oxide of iron1 which occurs only in small quantities1 has sometimes been considered fortuitous1 but it is almost invariably present1 and the experiments of ,prince ,salm ,horstmar leave no doubt that it is essential to the plant4 ,its function is unknown1 but it is an important constituent of the blood of herbivorous animals1 and may be present in the plant1 less for its own benefit than for that of the animal of which it is destined to become the food4 ,soda appears to be a comparatively unimportant constituent of the ash1 of which it generally forms but a small proportion1 although the instances of its entire absence are rare4 ,in the cruciferous plants 7turnip1 rape1 etc47 it is found abundantly1 and to them it appears indispensable1 but in most other plants it admits of replacement by potash4 ,it seems probable that where the soil is rich in the latter substance1 plants will select that alkali in preference to soda2 but as they must have a certain quantity of alkali1 the latter may supply the place of the former where it is deficient4 ,cultivation1 probably by enriching the soil in that element1 increases the proportion of potash found in the ash of plants1 as is remarkably seen in the asparagus1 which gave the following quantities of alkalies and chlorine3-- ,wild4 ,cultivated4 ,potash #ah4h #ej4e ,soda #af4b trace4 ,chlorine #af4e #h4c ,the soda having almost entirely disappeared in the cultivated plant1 while a corresponding increase had taken place in the quantity of potash4 ,potash is one of the most important elements of the ash of all plants1 rarely forming less than #bj1 and sometimes more than #ej per cent of its weight4 ,the latter proportion occurs chiefly in the roots and tubers1 but it is also abundant in all seeds and in the grasses4 ,the straw1 and particularly the chaff of the cereals1 and the leaves of most plants1 contain it in smaller quantity1 although exceptions to this are not unfrequent1 one of the most curious being the case of poppy-seed1 which contains only about #ab per cent1 while the leaves yield upwards of #cg per cent4 ,the proportion of lime varies within very wide limits1 being sometimes as low as #a1 and in other plants reaching #dj per cent of their ash4 ,the former proportion occurs in the grains of the cerealia1 and the latter in the leaves of some plants1 and more especially in the ,jerusalem artichoke4 ,the turnip and some of the leguminous plants also contain it abundantly4 ,magnesia is generally found in small quantity4 ,it is largest in the grains1 amounting in them to about #ab or #ac per cent of the ash1 but in other plants it varies from #b to #d per cent4 ,although small in quantity1 it is an important substance1 and apparently cannot be dispensed with2 at least there is no instance known of its entire absence4 ,chlorine is by no means an invariable constituent of the ash1 although it is generally present1 and sometimes in considerable quantity4 ,it is most abundant when the proportion of soda is large1 and exists in the ash principally in combination with that base as common salt4 ,the relation between these two elements may be traced more or less distinctly throughout the whole table of analyses1 and conspicuously in that of mangold-wurzel1 where the common salt amounts to almost exactly one-half of the whole mineral matter4 ,the analyses of the cultivated and uncultivated asparagus also show that a diminution in the soda is accompanied by a reduction in the proportion of chlorine4 ,sulphuric ,acid is an essential constituent of the ash4 ,but it is to be observed that it is in some instances entirely1 and in all partially1 a product of the combustion to which the plant has been submitted in order to obtain the ash4 ,it is partly derived from the sulphur contained in the albuminous compounds1 which is oxidised and converted into sulphuric acid during the process of burning the organic matter1 and remains in the ash4 ,the quantity of sulphuric acid found in the ash is1 however1 no criterion of that existing in the plant1 for a considerable quantity of it escapes during burning4 ,the extent to which this occurs in particular instances is well illustrated by reference to the case of white mustard1 which yields an ash containing only #b4ai of sulphuric acid1 equivalent to #j4i of sulphur2 and if calculated on the seed itself1 this will amount to no more than #j4jci per cent1 while experiments made in another manner prove it to contain about thirty times as much1 or more than #a per cent4 ,for the purpose of determining the total quantity of sulphur which the plants contain in their natural state1 it is necessary to oxidise them by means of nitric acid2 and from such experiments the following table1 showing the total amount of sulphur contained in #ajj parts of different plants1 dried at #bab deg41 has been constructed3-- ,poa palustris #j4afe ,lolium perenne #j4caj ,italian ,ryegrass #j4cbi ,trifolium pratense #j4ajg repens #j4jii ,lucerne #j4ccf ,vetch #j4agh ,potato tuber #j4jhb tops #j4bjf ,carrot1 root #j4jib tops #j4gde ,mangold-,wurzel1 root #j4jeh tops #j4ejb ,swede1 root #j4dce tops #j4deh ,rape #j4ddh ,drumhead ,cabbage #j4dca ,wheat1 grain #j4jfh straw #j4bde ,barley1 grain1 #j4jec straw #j4aia ,oats1 grain #j4ajc straw #j4bhi ,rye1 grain #j4jea ,beans #j4jef ,peas #j4abg ,lentils #j4aaj ,hops #a4jfc ,gold of ,pleasure #j4bec ,black ,mustard #a4agj ,white ,mustard #a4jej ,phosphoric acid1 which may be looked upon as the most important mineral constituent of plants1 is found to be present in very variable proportions4 ,the straws1 stems1 and leaves contain it in comparatively small quantity1 but in the seeds of all plants it is very abundant4 ,in these of the cereals it constitutes nearly half of their whole mineral components1 and it rarely falls below #cj per cent4 ,carbonic acid occurs in very variable quantities in the ash4 ,it is of comparatively little importance in itself1 and is really produced by the oxidation of part of the carbonaceous matters of the plant2 but it has a special interest1 in so far as it shows that part of the bases contained in the plant must in its natural state have been in union with organic acids1 or combined in some way with the organic constituents of the plant4 ,silica is an invariable constituent of the ash1 but in most plants occurs but in small quantity4 ,the cereals and grasses form an exception to this rule1 for in them it is an abundant and important element4 ,it is not1 however1 uniformly distributed through them1 but is accumulated to a large extent in the stem1 to the strength and rigidity of which it greatly contributes4 ,the hard shining layer which coats the exterior of straw1 and which is still more remarkably seen on the surface of the bamboo1 consists chiefly of silica2 and in the latter plant this element is sometimes so largely accumulated1 that concretions resembling opal1 and composed entirely of it1 are found loose within its joints4 ,the necessity for a large supply of silica in the stems of other plants does not exist1 and in them it rarely exceeds #e or #f per cent1 but in some leaves it is more abundant4 ,a knowledge of the composition of the ash of plants is of considerable importance in a practical point of view1 and enables us in many instances to explain why some plants will not grow upon particular soils on which others flourish4 ,thus1 for instance1 a plant which contains a large quantity of lime1 such as the bean or turnip1 will not grow in a soil in which that element is deficient1 although wheat or barley1 which require but little lime1 may yield excellent crops4 ,again1 if the soil be deficient in phosphoric acid1 those plants only will grow luxuriantly which require but a small quantity of that element1 and hence it follows that on such a soil plants cultivated for the sake of their stems1 roots1 or leaves1 in which the quantity of phosphoric acid is small1 may yield a good return2 while others1 cultivated for the sake of their seed1 in which the great proportion of that constituent of the ash is accumulated1 may yield a very small crop4 ,it is obvious also that even where a soil contains a proper quantity of all its ingredients1 the repeated cultivation of a plant which removes a large quantity of any individual element1 may1 in the course of time1 so far reduce the amount of that substance as to render the soil incapable of any longer producing that plant1 although1 if it be replaced by another which requires but little of the element thus removed1 it may again produce an abundant crop4 ,on this principle also1 attempts have been made to explain the rotation of crops1 which has been supposed to depend on the cultivation in successive years of plants which abstract from the soil preponderating quantities of different mineral matters4 ,but though this has unquestionably a certain influence1 we shall afterwards see reason to doubt whether it affords a sufficient explanation of all the observed phenomena4 ,it may be observed1 on examining the table of the percentage and position of the ash1 that some plants are especially rich in alkalies1 while in others lime or silica preponderate1 and it would therefore be the object of the farmer to employ1 in succession1 crops containing these elements in different proportions4 ,in carrying out this view1 attempts have been made to classify different plants under the heads of silica plants1 lime plants1 and potash plants2 and the following table1 extracted from ,liebig's ,agricultural ,chemistry1 in which the constituents of the ash are grouped under the three heads of salts of potash and soda1 lime and magnesia1 and silica1 gives such a classification as far as it is at present possible3-- ---------------------------------------- ------------------------------ ,salts of ,salts of ,silica4 ,potash and ,lime and ,soda4 ,magnesia4 ---------------------------------------- -------------------------- ,silica ,oat straw with seeds #cd4jj #d4jj #fb4jj ,plants4 ,wheat straw #bb4ej #g4bj #fa4ej ,barley straw with seeds #ai4jj #be4gj #ee4cj ,rye straw #ah4fe #af4eb #fc4hi ,good hay #f4jj #cd4jj #fj4jj ,lime ,tobacco #bd4cd #fg4dd #h4cj ,plants ,pea straw #bg4hb #fc4gd #g4ha ,potato plant #d4bj #ei4dj #cf4dj ,meadow ,clover #ci4bj #ef4jj #d4ij ,potash ,maize straw #gb4de #f4ej #ah4jj ,plants4 ,turnips #ha4fj #ah4dj -- ,beet root #hh4jj #ab4jj -- ,potatoes #he4ha #ad4ai -- ,jerusalem ,artichoke #hd4cj #ae4gj -- ---------------------------------------- ------------------------------ ,the special application of these facts must be reserved till we come to treat of the rotation of crops4 ,it is manifest that1 as the crops removed from the soil all contain a greater or less amount of inorganic matters1 they must be continually undergoing diminution1 and at length be completely exhausted unless their quantity is maintained from some external source4 ,in many cases the supply of these substances is so large that ages may elapse before this becomes apparent1 but where the quantity is small1 a system of reckless cropping may reduce a soil to a state of absolute sterility4 ,a remarkable illustration of this fact is found in the virgin soils of ,america1 from which the early settlers reaped almost unheard-of crops1 but1 by injudicious cultivation1 they were soon exhausted and abandoned1 new tracts being brought in and cultivated only to be in their turn abandoned4 ,the knowledge of the composition of the ash of plants assists us in ascertaining how this exhaustion may be avoided1 and indicates the mode in which such soils may be preserved in a fertile state4 ,,footnotes3 ,footnote ,a3 ,apparently a species of ,sinapis4 ,footnote ,b3 ,oxide of ,manganese1 #j4db4 ,footnote ,c3 ,oxide of ,manganese1 #j4ib4 ,footnote ,d3 ,alumina1 #a4jb4 ,footnote ,e3 ,alumina1 #j4fc4 ,footnote ,f3 ,iodide of ,potassium1 #j4dd2 ,sulphuret of ,sodium1 #c4ff4 ,footnote ,g3 ,iodide of ,potassium1 #j4bc4 ,footnote ,h3 ,iodide of ,potassium1 #a4fh4 ,,chapter ,v4 ,,the ,,soil--,,its ,,chemical ,,and ,,physical ,,characters4 ,no department of agricultural chemistry is surrounded with greater difficulties and uncertainties than that relating to the properties of the soil4 ,when chemistry began to be applied to agriculture1 it was not unnaturally supposed that the examination of the soil would enable us to ascertain with certainty the mode in which it might be most advantageously improved and cultivated1 and when1 as occasionally happened1 analysis revealed the absence of one or more of the essential constituents of the plant in a barren soil1 it indicated at once the cause and the cure of the defect4 ,but the expectations naturally formed from the facts then observed have been as yet very partially fulfilled2 for1 as our knowledge has advanced1 it has become apparent that it is only in rare instances that it is possible satisfactorily to connect together the composition and the properties of a soil1 and with each advancement in the accuracy and minuteness of our analysis the difficulties have been rather increased than diminished4 ,although it is occasionally possible to predicate from its composition that a particular soil will be incapable of supporting vegetation1 it not unfrequently happens that a fruitful and a barren soil are so similar that it is impossible to distinguish them from one another1 and cases even occur in which the barren appears superior to the fertile soil4 ,the cause of this apparently anomalous phenomenon lies in the fact that analysis1 however minute1 is unable to disclose all the conditions of fertility1 and that it must be supplemented by an examination of its physical and other chemical properties1 which are not indicated by ordinary experiments4 ,of late years very considerable progress has been made in the investigation of the properties of the soil1 and many facts of great importance have been discovered1 but we are still unable to assert that all the conditions of fertility are yet known1 and the practical application of those recently discovered is still very imperfectly understood4 ,it must not be supposed that a careful analysis of a soil is without value1 for very important practical deductions may often be drawn from it1 and when this is not practicable it is not unfrequently due to its being imperfect or incomplete1 for it is so complex that the cases in which all the necessary details have been eliminated are even now by no means numerous4 ,in fact1 the want of a large number of thorough analyses of soils of different kinds is a matter of some difficulty1 and so soon as a satisfactory mode of investigation can be determined upon1 a full examination of this subject would be of much importance4 ,origin of ,soils4--,the constituents of the soil1 like those of the plant1 may be divided into the great classes of organic and inorganic4 ,the origin of the former has been already discussed3 they are derived from the decay of plants which have already grown upon the soil1 and which1 in various stages of decomposition1 form the numerous class of substances grouped together under the name of humus4 ,the organic substances may therefore be considered as in a manner secondary constituents of the soil1 which have been accumulated in it as the consequence of the growth and decay of successive generations of plants1 while the primeval soil consisted of inorganic substances only4 ,the inorganic constituents of the soil are obtained as the result of a succession of chemical changes going on in the rocks which protrude through the surface of the earth4 ,we have only to examine one of these rocks to observe that it is constantly undergoing a series of important changes4 ,under the influence of air and moisture1 aided by the powerful agency of frost1 it is seen to become soft1 and gradually to disintegrate1 until it is finally converted into an uniform powder1 in which the structure of the original rock is with difficulty1 if at all distinguishable4 ,the rapidity with which these changes take place is very variable2 in the harder rocks1 such as granite and mica slate it is so slow as to be scarcely perceptible1 while in others1 such as the shales of the coal formation1 a very few years' exposure is sufficient for the purpose4 ,these actions1 operating through a long series of years1 are the source of the inorganic constituents of all soils4 ,geology points to a period at which the earth's surface must have been altogether devoid of soil1 and have consisted entirely of hard crystalline rocks1 such as granite and trap1 by the disintegration of which1 slowly proceeding from the creation down to the present time1 all the soils which now cover the surface have been formed4 ,but they have been produced by a succession of very complicated processes2 for these disintegrated rocks being washed away in the form of fine mud1 or at least of minute particles1 and being deposited at the bottom of the primeval seas1 have there hardened into what are called sedimentary rocks1 which being raised above the surface by volcanic action or other great geological forces1 have been again disintegrated to yield different soils4 ,thus1 then1 all soils are directly or indirectly derived from the crystalline rocks1 those overlying them being formed immediately by their decomposition1 while those found above the sedimentary rocks may be traced back through them to the crystalline rocks from which they were originally formed4 ,such being the case1 the composition of different soils must manifestly depend on that of the crystalline rocks from which they have been derived4 ,their number is by no means large1 and they all consist of mixtures in variable proportions of quartz1 felspar1 mica1 hornblende1 augite1 and zeolites4 ,with the exception of quartz and augite1 these names are1 however1 representatives of different classes of minerals4 ,there are1 for instance1 several different minerals commonly classified under the name of felspar1 which have been distinguished by mineralogists by the names of orthoclase1 albite1 oligoclase1 and labradorite2 and there are at least two sorts of mica1 two of hornblende1 and many varieties of zeolites4 ,quartz consists of pure silica1 and when in large masses is one of the most indestructible rocks4 ,it occurs1 however1 intermixed with other minerals in small crystals1 or irregular fragments1 and forms the entire mass of pure sand4 ,the four kinds of felspar which have been already named are compounds of silica with alumina1 and another base which is either potash1 soda1 or lime4 ,their composition is as follows1 two examples of each being given-- ---------------------------------------- ------------------------------------ ,orthoclase4 ,albite4 ,oligoclase4 ,labradorite4 ---------------------------------------- -------------------------------- ,silica #fe4gb #fe4jj #fg4ii #fh4bc #fb4gj #fc4ea #ed4ff #ed4fg ,alumina #ah4eg #ah4fd #ai4fa #ah4cj #bc4hj #bc4ji #bg4hg #bg4hi ,peroxide of iron traces #j4hc #j4gj #a4ja #j4fb -- -- #j4ca ,oxide of manganese traces #j4ac -- -- -- -- -- -- ,lime #j4cd #a4bc #j4ff #a4bf #d4fj #b4dd #ab4ja #aj4fj ,magnesia #j4aj #a4jc -- #j4ea #j4jb #j4gg -- #j4ah ,potash #ad4jb #i4ab -- #b4ec #a4je #b4ai -- #j4di ,soda #a4be #c4di #aa4ab #g4ii #h4jj #i4cg #e4df #e4je ---------------------------------------- ------------------------------------ #ajj4jj #ii4dgajj4jh #ii4hcajj4giaja4cgajj4jj #ii4ai ---------------------------------------- ------------------------------------- ,it is obvious that soils produced by the disintegration of these minerals must differ materially in quality4 ,those yielded by orthoclase must generally abound in potash1 while albite and labradorite1 containing little or none of that element1 must produce soils in which it is deficient4 ,the quality of the soil they yield is not however entirely dependent on the nature of the particular felspar which yields it1 but is also intimately connected with the extent to which the decomposition has advanced4 ,it is observed that different felspars undergo decomposition with different degrees of rapidity but after a certain time they all begin to lose their peculiar lustre1 acquire a dull and earthy appearance1 and at length fall into a more or less white and soft powder4 ,during this change water is absorbed1 and1 by the decomposing action of the air1 the alkaline silicate is gradually rendered soluble1 and at length entirely washed away1 leaving a substance which1 when mixed with water1 becomes plastic1 and has all the characters of common clay4 ,the nature of this change will be best seen by the following analysis of the clay produced during this composition1 which is employed in the manufacture of porcelain under the name of kaolin1 or china clay-- ,silica #df4hj ,alumina #cf4hc ,peroxide of iron #c4aa ,carbonate of lime #j4ee ,potash #j4bg ,water #ab4dd ---- #ajj4jj ,in this instance the decomposition of the felspar had reached its limit1 a mere trace of potash being left1 but if taken at different stages of the process1 variable proportions of that alkali are met with4 ,this decomposition of felspar is the source of the great deposits of clay which are so abundantly distributed over the globe1 and it takes place with nearly equal rapidity with potash and soda felspar4 ,it is rarely complete1 and the soils produced from it frequently contain a considerable proportion of the undecomposed mineral1 which continues for a long period to yield a supply of alkalies to the plants which grow on them4 ,mica is a very widely distributed mineral1 and two varieties of it are distinguished by mineralogists1 one of which is characterised by the large quantity of magnesia it contains4 ,different specimens are found to vary very greatly in composition1 but the following analyses may represent their most usual composition3 ,,mica4 ---------------- ,potash4 ,magnesia4 ,silica #df4cf #db4fe ,alumina #cf4hj #ab4if ,peroxide of iron #d4ec --- ,protoxide of iron --- #g4aa ,oxide of manganese #j4jb #a4jf ,magnesia --- #be4ge ,potash #i4bb #f4jc ,hydrofluoric acid #j4gj #j4fb ,water #a4hd #c4ag ---- ---- #ii4dg #ii4ce ,mica undergoes decomposition with extreme slowness1 as is at once illustrated by the fact that its shining scales may frequently be met with entirely unchanged in the soil4 ,its persistence is dependent on the small quantity of alkaline constituents which it contains2 and for this reason it is observed that the magnesian micas undergo decomposition less rapidly than those containing the larger quantity of potash4 ,eventually1 however1 both varieties become converted into clay1 their magnesia and potash passing gradually into soluble forms4 ,hornblende and augite are two widely distributed minerals1 which are so similar in composition and properties that they may be considered together4 ,of the former two varieties1 basaltic and common have been distinguished1 and their composition is given below3-- ,hornblende4 ---------------- ,common4 ,basaltic4 ,augite4 ,silica #da4ej #db4bd #ej4ab ,alumina #ae4ge #ac4ib #d4bj ,protoxide of iron #g4ge #ad4ei #aa4fj ,oxide of manganese #j4be #j4cc -- ,lime #ad4ji #ab4bd #bj4ee ,magnesia #ai4dj #ac4gd #ac4gj ,water #j4ej -- -- ---- ---- ---- #ii4bd #ig4je #ii4fg ,in these minerals alkalies are entirely absent1 and their decomposition is due to the presence of protoxide of iron1 which readily absorbs oxygen from the air1 when the magnesia is separated and a ferruginous clay left4 ,the minerals just referred to1 constitute the great bulk of the mountain masses1 but they are associated with many others which take part in the formation of the soil4 ,of these the most important are the zeolites which do not occur in large masses but are disseminated through the other rocks in small quantity4 ,they form a large class of minerals of which ,thomsonite and natrolite may be selected as examples-- ,thomsonite4 ,natrolite4 ,silica #ch4gc #dh4fh ,alumina #cj4hd #bf4cf ,lime #ac4dc -- ,potash #j4ed #j4bc ,soda #c4he #af4jj ,water #ac4ji #i4ee ---- ---- #ajj4dh #ajj4hc ,they are chiefly characterized by containing their silica in a soluble state1 and hence may yield that substance to the plants in a condition particularly favourable for absorption4 ,it is obvious from what has been stated that all these minerals are capable1 by their decomposition1 of yielding soft porous masses having the physical properties of soils1 but most of them would be devoid of many essential ingredients1 while not one of them would yield either phosphoric acid1 sulphuric acid1 or chlorine4 ,it has1 however1 been recently ascertained that certain of these minerals1 or at least the rocks formed from them1 contain minute1 but distinctly appreciable traces of phosphoric acid1 although in too small quantity to be detected by ordinary analysis2 and small quantities of chlorine and sulphuric acid may also in most instances be found4 ,still it will be observed that most of these minerals would yield a soil containing only two or three of those substances1 which1 as we have already learned1 are essential to the plant4 ,thus1 potash felspar1 while it would give abundance of potash1 would be but an inefficient source of lime and magnesia2 and labradorite1 which contains abundance of lime1 is altogether deficient in magnesia and potash4 ,nature has1 however1 provided against this difficulty1 for she has so arranged it that these minerals rarely occur alone1 the rocks which form our great mountain masses being composed of intimate mixtures of two or more of them1 and that in such a manner that the deficiencies of the one compensate those of the other4 ,we shall shortly mention the composition of these rocks4 ,granite is a mixture of quartz1 felspar1 and mica in variable proportions1 and the quality of the soil it yields depends on whether the variety of felspar present be orthoclase or albite4 ,when the former is the constituent1 granite yields soils of tolerable fertility1 provided their climatic conditions be favourable2 but it frequently occurs in high and exposed situations which are unfavourable to the growth of plants4 ,gneiss is a similar mixture1 but characterised by the predominance of mica1 and by its banded structure4 ,owing to the small quantity of felspar which it contains1 and the abundance of the difficulty decomposable mica1 the soils formed by its disintegration are generally inferior4 ,mica slate is also a mixture of quartz1 felspar1 and mica1 but consisting almost entirely of the latter ingredient1 and consequently presenting an extreme infertility4 ,the position of the granite1 gneiss1 and mica slate soils in this country is such that very few of them are of much value2 but in warm climates they not unfrequently produce abundant crops of grain4 ,syenite is a rock similar in composition to granite1 but having the mica replaced by hornblende1 which by its decomposition yields supplies of lime and magnesia more readily than they can be obtained from the less easily disintegrated mica4 ,for this reason soils produced from the syenitic rocks are frequently possessed of considerable fertility4 ,the series of rocks of which greenstone and trap are types1 and which are very widely distributed1 differ greatly in composition from those already mentioned4 ,they are divisible into two great classes1 which have received the names of diorite and dolerite1 the former a mixture of albite and hornblende1 the latter of augite and labradorite1 sometimes with considerable quantities of a sort of oligoclase containing both soda and lime1 and of different kinds of zeolitic minerals4 ,generally speaking1 the soils produced from diorite are superior to those from dolerite4 ,the albite which the former contains undergoes a rapid decomposition1 and yields abundance of soda along with some potash1 which is seldom altogether wanting1 while the hornblende supplies both lime and magnesia4 ,dolerite1 when composed entirely of augite and labradorite1 produces rather inferior soils2 but when it contains oligoclase and zeolites1 and comes under the head of basalt1 its disintegration is the source of soils remarkable for their fertility2 for these latter substances undergoing rapid decomposition furnish the plants with abundant supplies of alkalies and lime1 while the more slowly decomposing hornblende affords the necessary quantity of magnesia4 ,in addition to these1 the basaltic rocks are found to contain appreciable quantities of phosphoric acid1 so that they are in a condition to yield to the plant almost all its necessary constituents4 ,the different rocks now mentioned1 with a few others of less general distribution1 constitute the whole of our great mountain masses2 and while their general composition is such as has been stated1 they frequently contain disseminated through them quantities of other minerals which1 though in trifling quantity1 nevertheless add their quota of valuable constituents to the soils4 ,moreover1 the exact composition of the minerals of which the great masses of rocks are composed is liable to some variety4 ,those which we have taken as illustrations have been selected as typical of the minerals2 but it is not uncommon to find albite containing #b or #c per cent of potash1 labradorite with a considerable proportion of soda1 and zeolitic minerals containing several per cent of potash1 the presence of which must of course considerably modify the properties of the soils produced from them4 ,they are also greatly affected by the mechanical influences to which the rocks are exposed2 and being situated for the most part in elevated positions1 they are no sooner disintegrated than they are washed down by the rains4 ,a granite1 for instance1 as the result of disintegration1 has its felspar reduced to an impalpable powder1 while its quartz and mica remain1 the former entirely1 the latter in great part1 in the crystalline grains which existed originally in the granite4 ,if such a disintegrated granite remains on the spot1 it is easy to see what its composition must be2 but if exposed to the action of running water1 by which it is washed away from its original site1 a process of separation takes place1 the heavy grains of quartz are first deposited1 then the lighter mica1 and lastly the felspar4 ,thus there may be produced from the same granite1 soils of very different nature and composition1 from a pure and barren sand to a rich clay formed entirely of felspathic debris4 ,the sedimentary or stratified rocks are formed of particles carried down by water and deposited at the bottom of the primeval seas from which they have been upheaved in the course of geological changes4 ,the process of their formation may be watched at the present day at the mouths of all great rivers1 where a delta composed of the suspended matters carried down by the waters is slowly formed4 ,the nature of these rocks must therefore depend entirely on that of the country through which the river flows4 ,if its course runs through a country in which lime is abundant1 calcareous rocks will be deposited1 and if it passes through districts of different geological characters the deposit must necessarily consist of a mixture of the disintegrated particles of the different rocks the river has encountered4 ,for this reason it is impossible to enter upon a detailed account of their composition4 ,it is to be observed1 however1 that the particles of which they are composed1 though originally derived from the crystalline rocks1 have generally undergone a complex series of changes1 geology teaching that1 after deposition1 they may in their turn undergo disintegration and be carried away by water1 to be again deposited4 ,their composition must therefore vary not merely according to the nature of the rock from which they have been formed1 but also according to the extent to which the decomposition has gone1 and the successive changes to which they have been exposed4 ,they may be reduced to the three great classes of clays1 including the different kinds of clay slates1 shales1 etc41 sandstone and limestone4 ,it must be added also1 that many of them contain carbonaceous matters produced by the decomposition of early races of plants and animals1 and that mixtures of two or more of the different classes are frequent4 ,the purest clays are produced by the decomposition of felspar1 but almost all the crystalline rocks may produce them by the removal of their alkalies1 iron1 lime1 etc4 ,where circumstances have been favourable1 the whole of these substances are removed1 and the clay which remains consists almost entirely of silica and alumina1 and yields a soil which is almost barren1 not merely on account of the deficiency of many of the necessary elements of plants1 but because it is so stiff and impenetrable that the roots find their way into it with difficulty4 ,it rarely happens1 however1 that decomposition has advanced so far as to remove the whole of the alkalies1 which is exemplified by the following analyses of the fire clay of the coal formation1 and of transition clay slate3-- ,transition ,fire ,clay4 ,clay ,slate4 ,silica #fj4jc #ed4gg ,alumina #ad4ia #bh4fa ,peroxide of iron #h4id #d4ib ,lime #b4jh #j4eh ,magnesia #d4bb #a4ad ,potash #c4hg #a4jj ,soda -- #j4bd ,carbonic acid #e4fg #h4bd ,water ---- ---- #ii4gb #ii4ej ,the sandstones are derived from the siliceous particles of granite and other rocks1 and consist in many cases of nearly pure silica1 in which case their disintegration produces a barren sand1 but they more frequently contain an admixture of clay and micaceous scales1 which sometimes form a by no means inconsiderable portion of them4 ,such sandstones yield soils of better quality1 but they are always light and poor4 ,where they occur interstratified with clays1 still better soils are produced1 the mutual admixture of the disintegrated rocks affording a substance of intermediate properties1 in which the heaviness of the clay is tempered by the lightness of the sandstone4 ,limestone is one of the most widely distributed of the stratified rocks1 and in different localities occurs of very different composition4 ,limestones are divided into two classes1 common and magnesian2 the former a nearly pure carbonate of lime1 the latter a mixture of that substance with carbonate of magnesia4 ,but while these are the principal constituents1 it is not uncommon to find small quantities of phosphate and sulphate of lime1 which1 however trifling their proportions1 are not unimportant in an agricultural point of view4 ,the following analyses will serve to illustrate the general composition of these two sorts of limestone as they occur in the early geological formations3-- ,,common4 ,,magnesian4 ------------------------- ---------------------- ,mid-,lothian4 ,sutherland4 ,sutherland4 ,dumfries4 ,silica #b4jj #g4db #f4jj #b4ca ,peroxide of iron #j4de #j4gf #a4eg #b4jj and alumina ,carbonate of lime #ic4fa #hd4aa #ej4ba #eh4ha ,carbonate of #a4fb #g4de #da4bb #cf4da magnesia ,phosphate of lime #j4ef 444 444 444 ,sulphate of lime #j4ib 444 444 #j4aj ,organic matter #j4bj 444 444 444 ,water #j4ej 444 #j4fi 444 ---- ---- ---- ---- #ii4hf #ii4gd #ii4fi #ii4fc ,these limestones are hard and possess to a greater or less extent a crystalline texture4 ,they are replaced in later geological periods by others which are much softer1 and often purer1 of which the oolitic limestones1 so called from their resemblance to the roe of a fish1 and chalk are the most important4 ,other limestones are also known which contain an admixture of clay4 ,the soils produced by the disintegration of limestone and chalk are generally light and porous1 but when mixed with clay1 possess a very high degree of fertility1 and this is particularly the case with chalk1 which yields some of the most valuable of all soils4 ,but it is true only of the common limestones1 for experience has shown that those which contain magnesia in large quantity are often prejudicial to vegetation1 and sometimes yield barren or inferior soils4 ,such are the general characters of the three great classes of stratified rocks2 any attempt to particularise the numerous varieties of each would lead us far beyond the limits of the present work4 ,it is necessary1 however1 to remark1 that in many instances one variety passes into the other1 or1 more correctly speaking1 sedimentary rocks occur1 which are mixtures of two or more of the three great classes4 ,in fact1 the name given to each really expresses only the preponderating ingredient1 and many sandstones contain much clay1 shales and clay slates abound in lime1 and limestones in sand or clay1 so that it may sometimes be a matter of some difficulty to decide to which class they belong4 ,such mixtures usually produce better soils than either of their constituents separately1 and accordingly1 in those geological formations in which they occur1 the soils are generally of excellent quality4 ,the same effect is produced where numerous thin beds of members of the different classes are interstratified1 the disintegrated portions being gradually intermixed1 and valuable soils formed4 ,the fertility of the soils formed from the stratified rocks is also increased by the presence of organic remains which afford a supply of phosphoric acid1 and which are sometimes so abundant as to form a by no means unimportant part of their mass4 ,they do not occur in the oldest sedimentary rocks1 but as we ascend to the more recent geological epochs1 they increase in abundance1 until1 in the greensands and other recent formations1 whole beds of coprolites and other organic remains are met with4 ,great differences are observed in the quality of the soils yielded by different rocks4 ,in general1 those formed by the disintegration of clay slates are cold1 heavy1 and very difficult and expensive to work2 those of sandstone light and poor1 and of limestone often poor and thin4 ,these statements must1 however1 be considered as very general2 for individual cases occur in which some of these substances may produce good soils1 remarkable exceptions being offered by the lower chalk and some of the shales of the coal formation4 ,little is at present known regarding the peculiar nature of many of these rocks1 or their composition2 and the cause of the differences in the fertility of the soil produced from them is a subject worthy of minute investigation4 ,chemical ,composition of the ,soil4--,reference has been already made to the division of the constituents of the soil into the two great classes of organic and inorganic4 ,and when treating of the sources of the organic constituents of plants1 we entered with some degree of minuteness into the composition and relations of the different members of the former class1 and expressed the opinion that they did not admit of being directly absorbed by the plant4 ,but though the parts then stated lead to the inference that1 as a direct source of these substances1 humus is unimportant1 it has other functions to perform which render it an essential constituent of all fertile soils4 ,these functions are dependent partly on the power which it has of absorbing and entering into chemical composition with ammonia1 and with certain of the soluble inorganic substances1 and partly on the effect which the carbonic acid produced by its decomposition exerts on the mineral matters of the soil4 ,in the former way1 its effects are strikingly seen in the manner in which ammonia is absorbed by peat2 for it suffices merely to pour upon some dried peat a small quantity of a dilute solution of ammonia to find its smell immediately disappear4 ,this peculiar absorptive power extends also to the fixed alkalies1 potash and soda1 as well as to lime and magnesia1 and has an important effect in preventing these substances being washed out of the soil--a property which1 as we shall afterwards see1 is possessed also by the clay contained in greater or less quantity in most soils4 ,on the other hand1 the air and moisture which penetrate the soil cause its decomposition1 and the carbonic acid so produced attacks the undecomposed minerals existing in it1 and liberate the valuable substances they contain4 ,in considering the composition of a soil1 it is important to bear in mind that it is a substance of great complexity1 not merely because it contains a large number of chemical elements1 but also because it is made up of a mixture of several minerals in a more or less decomposed state4 ,the most cursory examination shows that it almost invariably contains sand and scales of mica1 and other substances can often be detected in it4 ,now it has been already observed that the minerals of which soils are composed1 differ to a remarkable extent in the facility with which they undergo decomposition1 and the bearing of this fact on its fertility is a matter of the highest importance1 for it has been found that the mere presence of an abundant supply of all the essential constituents of plants is not always sufficient to constitute a fertile soil4 ,two soils1 for instance1 may be found on analysis to have exactly the same composition1 although in practice one proves barren and the other fertile4 ,the cause of this difference lies in the particular state of combination in which the elements are contained in them1 and unless this be such that the plant is capable of absorbing them1 it is immaterial in what quantity they are present1 for they are thus locked up from use1 and condemn the soil to hopeless infertility4 ,it is admitted that unless the substances be present in a state in which they can be dissolved1 the plant is incapable of absorbing them2 but it is a matter of doubt whether it is necessary that they be actually dissolved in the water which permeates the soil1 or whether the plant is capable of exercising a directly solvent action4 ,the latter view is the most probable1 but at the same time it cannot be doubted1 that if they are presented to the plant in solution1 they will be absorbed in that state in preference to any other4 ,hence it has been considered important in the analysis of a soil1 not to rest content with the determination of the quantity of each element it contains1 but to obtain some indication of the state of combination in which it exists1 so as to have some idea of the ease or difficulty with which they may be absorbed4 ,for this purpose it is necessary to determine1 #ast1 ,the substances soluble in water2 #b;d1 ,those insoluble in water1 but soluble in acids2 #c;d1 ,those insoluble both in water and acids2 and if to these the organic constituents be added1 there are four separate heads under which the components of a soil ought to be classified4 ,this classification is accordingly adopted in the most careful and minute analyses2 but the difficulty and labour attending them has hitherto precluded the possibility of making them except in a few instances2 and1 generally speaking1 chemists have been contented with treating the soil with an acid1 and determining in the solution all that is dissolved4 ,such analyses are often useful for practical purposes1 as for example1 when they show the absence of lime1 or any other individual substance1 by the addition of which we may rectify the deficiency of the soil2 but they are of comparatively little scientific value1 and throw but little light on the true constitution of the soil1 and the sources of its fertility4 ,nor is it likely that much satisfactory information will be obtained until the number of minute analyses is so far extended as to establish the fundamental principles on which the various properties of the soil depends4 ,the separation of the constituents of a soil into the four great groups already mentioned1 is effected in the following manner3--,a given quantity of the soil is boiled with three or four successive quantities of water1 which dissolves out all the soluble matters4 ,these generally amount to about one-half per cent of the whole soil1 and consist of nearly equal proportions of organic and inorganic substances4 ,in very light and sandy soils1 it occasionally happens that not more than one or two-tenths per cent dissolve in water1 and in peaty soils1 on the other hand1 the proportion is sometimes considerably increased1 principally owing to the abundance of soluble organic matters4 ,when the residue of this operation is treated with dilute hydrochloric acid1 the matters soluble in acids are obtained in the fluid4 ,the proportion of these substances is liable to very great variations1 and in some soils of excellent quality1 and well adapted to the growth of wheat1 it does not exceed #c per cent2 while in calcareous soils1 such as those of the chalk formation1 it may reach as much as #ej or #fj per cent4 ,in general1 however1 it amounts to about #aj per cent4 ,the organic constituents are also very variable in amount2 ordinary soils of good quality containing from #b to #aj per cent1 while in peat soils they not unfrequently reach #cj or even #ej per cent4 ,but these cannot be considered fertile soils4 ,the insoluble constituents are likewise subject to great variations1 but1 in the ordinary clay and sandy soils of this country1 they generally form from #gj to #he per cent of the whole4 ,the distribution of the constituents under these different heads will be best illustrated by a few analyses of soils of good quality1 and for this purpose we shall select two1 noted for the excellent crops of wheat they produce1 and for their general fertility4 ,the analyses were made from the upper #aj inches1 and a quantity of the #aj inches immediately subjacent was analysed as subsoil4 ,the first is the ordinary wheat soil of the county of ,mid-,lothian1 the other the alluvial soil of the ,carse of ,gowrie in ,perthshire1 so celebrated for the abundance and luxuriance of the crops it produces4 ---------------------------------------- --------------------- ,mid-,lothian4 ,perthshire4 ---------------------------------------- -------------------- ,soil4 ,subsoil4 ,soil4 ,subsoil4 ---------------------------------------- ------------------ ,,substances ,,soluble ,,in ,,water4 ,silica #j4jadi #j4jajd #j4jjgb #j4jdfa ,lime #j4jcjj #j4jjgb #j4jahd #j4jcjf ,magnesia #j4jjig #j4jjaf #j4jjdj #j4jjcd ,chlor4 of magnesium -- -- -- #j4jjcc ,potash #j4jjcd #j4jjcg -- -- ,soda #j4jjfe #j4jjdi -- -- ,chloride of potassium -- -- #j4jjhh #j4jjhj ,chloride of sodium -- -- #j4jaaj #j4jaff ,sulphuric acid #j4jaic #j4jabd #j4jjhi #j4jbci ,chlorine trace trace -- -- ,organic matters #j4adha #j4bbbh #j4jfjh #j4acdb ------------------------------------ #j4bcai #j4bfcj #j4aaia #j4bffa ---------------------------------------- ------------------ ,,soluble ,,in ,,acids4 ,silica #j4adij #j4jfhj #j4jdhb #j4afig ,peroxide of iron #e4agcj #c4dhbj #d4hgjj #d4ffcc ,alumina #b4aedj #a4hacj #b4fijj #c4ijgj ,lime #j4ddgj #j4chaj #j4cfaf #j4ejej ,magnesia #j4dabj #j4bhej #j4cifj #j4idbj ,potash #j4jfej #j4afej #j4cdde #j4afgj ,soda #j4jjej #j4jefj #j4abdb #j4aibj ,sulphuric acid #j4jbej #j4jhej #j4jiaa #j4jafj ,phosphoric acid #j4dcjj #j4aigj #j4bdjj #j4bfhj ,carbonic acid -- -- #j4jejj -- ---------------------------------- #h4hfjj #f4ecbj #i4baef #aj4hcjj ---------------------------------- ,,insoluble ,,in ,,acids4 ,silica #ga4chij #hb4ejij #fc4adjj #fa4dbjj ,alumina #d4ghaj #c4eabj #aa4cejj #aj4cdjj ,peroxide of iron trace trace -- #a4efgj ,lime #j4gebj #j4eejj #j4dejj #j4gdjj ,magnesia #j4ffaj #j4eejj #j4fbjj #j4ddej ,potash #j4bhfj -- #b4dejj #b4jjcj ,soda #j4dbbj -- #a4cajj #j4hddj ---------------------------------- #gh4biaj #hg4abaj #gi4cbjj #gg4ceij ---------------------------------- ,,organic ,,matters4 ,insoluble organic matter #h4hggg #d4bcgj #g4gdjj #f4biaj ,humine #j4hhej #j4cdej #j4jgjj #j4jhdj ,humic acid #j4acdj #j4jcaj #j4fhjj #j4cfjj ,apocrenic acid #j4aecc -- -- #j4jibi ,water #b4fhdj #a4gfgj #b4gjjj #d4egej ---------------------------------- #ab4gcdj #f4chjj #aa4aijj #aa4djbj ,sum of all the constituents #ajj4aafi #ajj4bifj #ii4hddg #ii4hega ,,amount ,,of ,,carbon1 ,,hydrogen1 ,,nitrogen1 ,,and ,,oxygen ,,contained ,,in #ajj ,,parts ,,of ,,each ,,soil4 ,carbon #d4eaj #a4cjfj #b4ee #b4jc ,hydrogen #j4eej #j4ccbd #j4ga #j4ec ,nitrogen #j4bbj #j4jigc #j4ba #j4ag ,oxygen #d4iah #c4ajja #e4jh #d4ji ---------------------------------- #aj4aih #d4hceh #h4ee #f4hb ---------------------------------------- ----------------------- ,in examining these analyses1 it is particularly worthy of notice that by far the larger proportion of the substances soluble in water consists of organic matter1 lime1 and sulphuric acid1 the two last being in combination as sulphate of lime1 while some of those substances which are usually considered to be the most important mineral constituents of plants are present in very small quantity--potash1 for instance1 forming not more than #a-be1jjjth of the whole soil1 and phosphoric acid being entirely absent4 ,on the other hand1 this portion contains the whole of the chlorine which exists in the soil1 and this might be anticipated from the ready solubility in water of the compounds of that substance4 ,the portion soluble in acids consists of alumina and oxide of iron1 both of which are comparatively unimportant to the plant1 but very important1 as we shall afterwards see1 in relation to the physical properties of the soil4 ,the remainder of the substances soluble in acids1 amounting to from #a and #b per cent1 is composed of some of the most essential constituents of plants4 ,lime1 magnesia1 potash1 and soda1 appear again in larger quantity than in the soluble part1 and along with them we have the phosphoric acid to the amount of from #j4b to #j4d per cent of the whole soil1 and sulphuric acid in much smaller quantity4 ,the insoluble matters differ remarkably in the two soils1 that from the ,carse of ,gowrie being characterised by a large quantity of potash and soda1 indicating an important difference in the materials from which they have been formed4 ,in the ,perthshire soil it is obvious that the felspathic element has been abundant1 and that its decomposition has been arrested at a time1 when it still contained a large quantity of alkalies4 ,and this difference is of great practical importance1 because those soils1 which contain a large quantity of potash in their insoluble portion1 have within them a source of permanent fertility1 the alkali being gradually liberated by the decomposition which is constantly in progress1 owing to the air and moisture permeating the soil4 ,as regards the special distribution of the inorganic matters1 it is to be observed that some of them occur in each of the three heads under which they are arranged1 while others are confined to one or two4 ,silica and the alkalies occur generally1 though not invariably1 in all three4 ,chlorine is met with only in the part soluble in water1 phosphoric acid only in that soluble in acids1 while sulphuric acid occurs in both the last-named divisions4 ,the greater part of the organic matters are insoluble both in water and acids4 ,at least it is generally believed that any portion dissolved by strong acids1 in the course of analysis1 has been entirely decomposed1 and is in a completely different state from that in which it existed actually in the soil4 ,as an example of a calcareous soil1 forming a striking contrast to those given above1 we select one from the island of ,antigua1 from which very large crops of sugar-cane are obtained4 ,the soil is of great depth1 and analyses of the subsoil at the depth of #ah inches and #e feet are given4 ,these last analyses are not so minute as that of the soil itself1 the soluble matters not having been separately determined1 but included in that soluble in acids4 ---------------------------------------- ----------------- ,surface #ah inches #e feet ,soil4 deep4 deep4 ---------------------------------------- ----------------- ,,soluble ,,in ,,water4 ,lime #j4jg 444 444 ,magnesia trace 444 444 ,potash #j4jf 444 444 ,soda #j4jd 444 444 ,chlorine #j4je 444 444 ,organic matter #j4ae 444 444 ---- #j4cg ,,soluble ,,in ,,acids4 ,silica #j4gd 444 444 ,peroxide of iron #b4bb #a4fg #a4hg ,protoxide of iron #j4gg #i4je #c4aj ,alumina #a4ij #b4eb #d4ba ,lime #aj4dc #c4jd #be4ge ,magnesia #j4bj #j4ed #j4ea ,potash #j4jc #j4bi #j4bh ,soda #j4jb #j4aa #j4af ,sulphuric acid trace #j4jb #j4ac ,phosphoric acid #j4ad trace #j4jd ,carbonic acid #g4ch #j4hb #bj4bc ----- ----- ----- #bc4hc #ah4jf #ef4bh ,,insoluble ,,in ,,acids4 ,silica #da4dd #ea4bd #bg4fg ,protoxide of iron #c4bd #j4bf #a4dj ,alumina #i4jj #a4ej #a4jj ,lime #j4jh #j4hh trace ,magnesia #j4hj #j4ed trace ,potash 444 #j4gd 444 ,soda 444 #j4be 444 ----- ----- ----- #ed4ef #ee4da #cj4jg ,,organic ,,matters4 ,humine #a4eh ,humic acid #a4ae #ab4je #g4di ,insoluble organic matters #g4ff ,water #aa4ac #ad4fi #f4jf ----- ----- ----- #ba4eb #bf4gd #ac4ee ---------------------------- ,sum of all the constituents #ajj4bh #ajj4ba #ii4ij ---------------------------------------- ----------------- ,in this soil there is a general resemblance in the composition of the portion soluble in water to those of the wheat soils4 ,but the part soluble in acids is distinguished by the great abundance of carbonate of lime4 ,the subsoil contains also a large quantity of protoxide of iron1 a substance frequently found in subsoils containing much organic matter1 and to which the air has imperfect access4 ,under these circumstances peroxide of iron is reduced to protoxide2 and when present abundantly in the soil in that form1 iron has been found to exercise a very injurious influence on vegetation2 and it has frequently happened that when subsoils containing it have been brought up to the surface1 they have in the first instance caused a manifest deterioration of the soil1 although after some time1 when it had become peroxidised by the action of the air1 it ceased to be injurious4 ,the soil of ,holland1 from the neighbourhood of the ,zuider ,zee1 which is an alluvial deposit from the waters of the ,rhine1 and produces large crops1 gave the results which follow-- ---------------------------------------- --------------------- ,surface4 #ae inches #cj inches deep4 deep4 ---------------------------------------- --------------------- ,insoluble silica #eg4fdf #ea4gjf #ee4cgb ,soluble silica #b4cdj #b4dif #b4bhf ,alumina #a4hcj #b4ijj #b4hhh ,peroxide of iron #i4jci #aj4cje #aa4hfd ,protoxide of iron #j4cej #j4efc #j4bjj ,oxide of manganese #j4bhh #j4ced #j4bhd ,lime #d4jib #e4jif #b4dhj ,magnesia #j4acj #j4adj #j4abh ,potash #a4jbf #a4dcj #a4eba ,soda #a4igb #b4jfi #a4icg ,ammonia #j4jfj #j4jgh #j4jge ,phosphoric acid #j4dff #j4cbd #j4dgh ,sulphuric acid #j4hif #a4ajd #j4egf ,carbonic acid #f4jhe #f4idj #d4gge ,chlorine #a4bdj #a4cjb #a4dah ,humic acid #b4gih #c4iia #c4dbh ,crenic acid #j4gga #j4gca #j4jcg ,apocrenic acid #j4ajg #j4afj #j4aeb ,other organic matters and ,combined water #h4cbd #g4gjj #i4cdh ,loss #j4edj #j4faa #j4gec ------- ------- ------- #ajj4jjj #ajj4jjj #ajj4jjj ---------------------------------------- --------------------- ,it is unnecessary to multiply analyses of fertile soils1 those now given being sufficient to show their general composition4 ,they are all characterised by the presence1 in considerable quantity1 of all the essential constituents of plants1 in a state in which they may be readily absorbed4 ,the absence of one or more of these substances immediately diminishes or altogether destroys the fertility of the soil2 and the extent to which this occurs is illustrated by the following analysis of a soil from ,pumpherston1 ,mid-,lothian1 forming a small patch in the lower part of a field1 and on which nothing would grow4 ,being naturally wet1 it had been drained and sowed with oats1 which died out about six weeks after sowing1 and left a bare soil on which weeds did not show the slightest disposition to grow4 ,,soluble ,,in ,,acids4 ,soluble silica #j4agc ,peroxide of iron #f4gge ,alumina #a4aej ,oxide of manganese trace ,carbonate of lime #j4hef ,magnesia #j4jii ,potash #j4acb ,soda #j4abc ,phosphoric acid trace ,chlorine trace ---- #i4cjh ,silica #gc4jif ,peroxide of iron #a4cga ,alumina #d4bfc ,lime #j4heh ,magnesia #j4ebj ---- #hj4ajh ,organic matter #h4jab ,water #b4cia ---- #aj4djc ------ #ii4hai ,in this instance the barrenness of the soil is distinctly traceable to the deficiency of phosphoric acid1 sulphuric acid1 and chlorine4 ,there is also a remarkably large quantity of oxide of iron1 which1 when acted on by the humic acid1 is well known to be highly prejudicial to vegetation1 and that this took place was shown by the fact that the drains1 a couple of months after being laid1 were almost stopped up by humate of iron4 ,still more striking are the following analyses3-- ---------------------------------------- ------------------------ ,moorland soil ,sandy soil ,soil from near ,aurich1 near near ,east ,friesland4 ,wettingen4 ,muhlhausen4 ---------------------------------------- ------------------------ ,silica and sand #gj4egf #if4jjj #gg4dij ,alumina #a4jej #j4ejj #i4dij ,oxide of iron #j4beb #b4jjj #e4hjj ,oxide of manganese trace trace #j4aje ,lime #j4jja #j4hff ,magnesia #j4jab #j4gbh ,potash trace ,soda trace trace ,phosphoric acid #j4jjc ,sulphuric acid trace ,carbonic acid 444 444 #j4bjj ,chlorine trace trace trace ,humic acid #aa4iaj #j4bjj #j4gcb ,insoluble humus #af4bjj #a4bii #j4bjj ,water 444 444 #d4jif ---------------------------------------- -- #ajj4jjj #ajj4jjj #ajj4jjj ---------------------------------------- ------------------------ ,the results contained in these analyses are peculiarly remarkable1 for they indicate the almost total absence of all those substances which the plant requires4 ,they must1 however1 be considered as in a great measure exceptional cases1 as it is but rarely that so large a number of constituents is absent1 and it is much more frequent to find the deficiency restricted to one or two substances4 ,they are illustrations of barrenness dependent on different circumstances4 ,the first shows the unimportance of the organic matters of the soil1 which are here unusually abundant1 without in any way counteracting the infertility dependent on the absence of the other constituents4 ,the second is that of a nearly pure sand2 and the third1 though it contains a greater number of the essential ingredients of the ash1 is still rendered unfruitful by the deficiency of alkalies1 sulphuric acid1 and chlorine4 ,an examination of the foregoing analyses indicates pretty clearly some of the conditions of fertility of the soil1 which must obviously contain all the constituents of the plants destined to grow upon it4 ,but it by no means exhausts the subject1 for numerous instances are known of soils containing all the essential elements of plants in abundance1 but on which they nevertheless refuse to grow4 ,in these instances the defect is due either to the presence of some substance injurious to the plant1 or to the state of combination of those it requires being such as to prevent their absorption4 ,reference has been already made to the bad effects of protoxide of iron1 and it would appear that organic matter is sometimes injurious4 ,even water1 by excluding air1 and so preventing those decompositions which play so important a part in liberating the essential elements from their more permanent compounds1 although it cannot render a soil absolutely barren1 not unfrequently materially diminishes its fertility4 ,the state of combination of the soil constituents unquestionably exercise a most important influence on its fertility4 ,that this must be the case is an inference which may be easily drawn from the statements already made regarding the different minerals from which it is directly or indirectly produced4 ,if1 for instance1 a soil consist to a large extent of mica1 it would be found on analysis to contain abundance of potash and some other matters1 and yet our knowledge of the difficulty with which that mineral is decomposed1 would enable us to pronounce unfavourably of the soil2 and practical experience here fully confirms the scientific inference4 ,the forms of combination most favourable to fertility is a subject on which our information is at present comparatively limited4 ,it was at one time believed that solubility in water was an indispensable requisite1 but recent investigations appear to lead to a directly contrary conclusion4 ,the analyses of soils already given1 show that the part directly soluble in water embraces only a certain number of the constituents of the plant1 and of those dissolved the quantity is very small4 ,this becomes still more apparent if we estimate from the analyses the actual quantities of those substances contained in an acre of soil4 ,it is generally assumed that the soil on an imperial acre of land #aj inches deep weighs in round numbers about #ajjj tons2 and calculating from this1 we find that the quantity of potash soluble in water in the ,mid-,lothian wheat soil1 amounts to no more than #gj lb4 per acre4 ,but a crop of hay carries off from the soil about #ch lb4 of potash1 and one of turnips1 including tops1 not less than #bjj lb41 so that if only the matters soluble in water could be taken up by the plant1 such soils could not possess the amount of fertility which they are actually found to have4 ,it is to be remembered1 also1 that in these analyses the experiment is made under the most favourable circumstances for ascertaining the whole quantity of matters which are capable of dissolving in water2 that practically dissolved is very different4 ,the recent analysis by ,krocker and ,way of the drainage water of soils afford a means of estimating this4 ,way found in one gallon of the drainage water from seven different fields1 collected in the end of ,december-- ---------------------------------------- --------------------- #a #b #c #d #e #f #g ---------------------------------------- --------------------- ,potash1 trace trace #j4jb #j4je trace #j4bb trace ,soda1 #a4jj #b4ag #b4bf #j4hg #a4db #a4dj #c4bj ,lime1 #d4he #g4ai #f4je #b4bf #b4eb #e4hb #ac4jj ,magnesia1 #j4fh #b4cb #b4dh #j4da #j4ba #j4ic #b4ej ,iron and ,alumina1 #j4dj #j4je #j4aj none #a4cj #j4ce #j4ej ,silica1 #j4ie #j4de #j4ee #a4bj #a4hj #j4fe #j4he ,chlorine1 #j4gj #a4aj #a4bg #j4ha #a4bf #a4ba #b4fb ,sulphuric acid1 #a4fe #e4ae #d4dj #a4ga #a4bi #c4ab #i4ea ,phosphoric acid1 trace #j4ab trace trace #j4jh #j4jf #j4ab ,ammonia1 #j4jah #j4jah #j4jah #j4jab #j4jah #j4jjf #j4jah ,nitric acid1 #g4ag #ad4gd #ab4gb #a4ie #c4de #h4je #aa4de ,organic matter1 #g4jj #g4dj #ab4ej #e4fj #e4gj #e4hj #g4dj ---------------------------------------- --------------------- ,some of the soils from which these waters were obtained had been manured with unusually large quantities of nitrogenous matters1 which accounts for the large amount of nitric acid1 as well as the lime which that acid has extracted4 ,dr4 ,krocker's analyses were made on soils less highly manured1 and the water was collected in summer4 ---------------------------------------- ------------------------------- ,,in #aj1jjj ,,parts4 ---------------------------------------- --- #a #b #c #d #e #f ---------------------------------------- -------------------------- ,organic matter #j4be #j4bd #j4af #j4jf #j4fc #j4ef ,carbonate of lime #j4hd #j4hd #a4bg #j4gi #j4ga #j4hd ,sulphate of lime #b4jh #b4aj #a4ad #j4ag #j4gg #j4gb ,nitrate of lime #j4jb #j4jb #j4ja #j4jb #j4jb #j4jb ,carbonate of magnesia #j4gj #j4fi #j4dg #j4bg #j4bg #j4af ,carbonate of iron #j4jd #j4jd #j4jd #j4jb #j4jb #j4ja ,potash #j4jb #j4jb #j4jb #j4jb #j4jd #j4jf ,soda #j4aa #j4ae #j4ac #j4aj #j4je #j4jd ,chloride of sodium #j4jh #j4jh #j4jg #j4jc #j4ja #j4ja ,silica #j4jg #j4jg #j4jf #j4je #j4jf #j4je ---------------------------------------- -------------------------- ,in order to obtain from these experiments an estimate of the quantity of the substances actually dissolved1 we shall select the results obtained by ,way4 ,the average rainfall in ,kent1 where the waters he examined were obtained1 is #be inches4 ,now1 it appears that about two-fifths of all the rain which falls escapes through the drains1 and the rest is got rid of by evaporation4 ,an inch of rain falling on an imperial acre weighs rather more than a hundred tons2 hence1 in the course of a year1 there must pass off by the drains about #ajjj tons of drainage water1 carrying with it1 out of the reach of the plants1 such substances as it has dissolved1 and #aejj tons must remain to give to the plant all that it holds in solution4 ,these #aejj tons of water must1 if they have the same composition as that which escapes1 contain only two and a half pounds of potash1 and less than a pound of ammonia4 ,it may be alleged that the water which remains1 lying longer in contact with the soil1 may contain a larger quantity of matters in solution2 but even admitting this to be the case1 it cannot for a moment be supposed that they can ever amount to more than a very small fraction of what is required for a single crop4 ,it may therefore be stated with certainty that solubility in water is not essential to the absorption of substances by the plant1 which must possess the power of itself directly attacking1 acting chemically on1 and dissolving them4 ,the mode in which it does this is entirely unknown1 but it in all probability depends on very feeble chemical actions1 and hence the importance of having the soil constituents1 not in solution1 but in such a state that they may be readily made soluble by the plants4 ,many of the minerals from which fertile soils are formed are probably not attackable by plants when in their natural condition1 and even after disintegration the quantity of the essential elements of their food1 which are present in an easily assimilable state1 is at no one time very large4 ,but this is of comparatively little importance1 for the soil is not an inert unchangeable substance2 it is the theatre of an important series of chemical changes effected by the action of air and moisture1 and producing a continued liberation of its constituents4 ,this decomposition is effected partly by the carbonic acid of the atmosphere1 but to a much larger extent by its oxygen acting upon the organic matters of the soil1 and causing a constant though slow evolution of that acid1 which in its turn attacks the mineral matters4 ,boussingault and ,levy have illustrated the extent of this action by examining the composition of the air contained in the pores of different soils1 and have obtained the following results3-- ---------------------------------------- ---------------------------------- ,nature of ,crop4 ,no4 of cubic #ajj ,,volumes ,,of ,,air ,,contain ,soil4 inches of air ------------------------- in #cd cubic ,carbonic ,oxygen4,nitrogen4 inches of soil acid4 ---------------------------------------- -------------------------------- ,light sandy soil1 newly manured 444 #h4j #b4ag 444 444 ,do4 manured #h days before 444 444 #a4ed #ah4hj #gi4ff ,do4 long ,yellow after manuring turnip #g4i #j4ic #ai4ej #gi4eg ,very sandy ,vineyard #i4f #a4jf #ai4gb #gi4bb ,sandy1 with many stones ,forest #d4j #j4hg #ai4fa #gi4eb ,loamy 444 #b4d #j4df 444 444 ,sandy1 subsoil of the last 444 #c4j #j4bd 444 444 ,sandy soil1 long after manuring ,trefoil #g4f #j4gd #ai4jb #hj4bd ,do4 ,recently manured 444 444 #j4he #ai4da #gi4gd ,do4 manured #h days before 444 444 #a4ed #ah4hj #gi4ff ,heavy clay ,jerusalem #g4j #j4ff #ai4ii #gi4ce artichoke ,fertile soil 7moist7,meadow #e4e #a4gi #ai4da #gh4hj ---------------------------------------- -------------------------------- ,from these analyses it appears that the air contained in the pores of the soil is much richer in carbonic acid than the atmosphere1 the poorest soil containing about #be times1 and a recently manured soil #bej times as much4 ,this carbonic acid1 which is obviously produced by the decomposition of the vegetable matters and manure1 acting partly as gas and partly dissolved in the soil water1 exerts a solvent action on its constituents4 ,and1 though a very feeble acid1 its continuous action produces in the course of time a large effect2 while1 during the interval1 the constituents of the soil are safely stored up1 and liberated only as the plant requires them1 by which bountiful provision of nature they are exposed to fewer risks of loss than if they had been all along in a state in which they could be absorbed4 ,carbonic acid not only assists in effecting the decomposition of the minerals of the soil1 but its aqueous solution acts as a solvent of many substances1 which are quite insoluble in pure water4 ,it is in this way that much of the lime contained in natural waters is held in solution1 and it has been ascertained that magnesia1 iron1 and even phosphate of lime1 may also be dissolved by it4 ,it is probable that when these substances are dissolved1 the plants will take them from solution in place of themselves attacking the insoluble matters2 but of the extent to which this may occur nothing is yet known--the action of solvents on the soil being a subject which is as yet scarcely examined4 ,carbonic acid is1 however1 a most important agent in producing the chemical changes in the soil1 and the particular value of humus lies in its affording a supply of that substance exactly when it is wanted2 but the carbonic acid of the atmosphere also takes part in these changes1 although with different degrees of rapidity according to the character of the soil1 acting rapidly in light1 and slowly in stiff1 clay soils4 ,the solvent action of the carbonic acid is1 no doubt1 principally exerted on the substances soluble in acids1 but not entirely1 for it is known that the insoluble part is gradually being disintegrated and made soluble2 and hence it is that the composition of that part of the soil which resists the action of acids1 and which at first sight might appear of no moment1 is really important4 ,it is obvious that this circumstance must at once confer on the soil of the ,carse of ,gowrie a great superiority over those of ,mid-,lothian and most other districts2 for it contains in its insoluble part a quantity of alkalies which must necessarily form a source of continued fertility4 ,accordingly1 experience has all along shown the great superiority of that soil1 and of alluvial soils generally1 which are all more or less similar to it4 ,the facility with which these matters are attackable by carbonic acid is also an important element of the fertility of a soil1 and it is to the existence of compounds which are readily decomposed by it that we attribute the high fertility of the trap soils4 ,by a further examination of the analyses of fertile soils1 it is at once apparent that the most essential constituents of plants are by no means very abundant in them4 ,in fact1 phosphoric and sulphuric acids1 lime1 magnesia1 and the alkalies1 which in most instances make up nine-tenths of the ash of plants1 form but a small portion of even the most fertile soils2 while silica1 which1 except in the grasses1 occurs in small quantity1 oxide of iron which is a limited1 and alumina a rare1 constituent of the ash1 constitute by far their larger part4 ,thus the total amount of potash1 soda1 lime1 magnesia1 phosphoric and sulphuric acids and chlorine1 contained in the ,mid-,lothian wheat soil amounts only to #c4ehhh per cent1 and in the ,perthshire to #f4dche1 the entire remainder being substances which enter into the plant for the most part in much smaller quantity4 ,and1 as these small quantities of the more important substances are capable of supplying the wants of the plant1 it must be obvious that a very small fraction of the silica1 oxide of iron1 and alumina1 which the soils contain1 would afford to it the whole quantity of these substances it requires1 and that the remainder must have some other functions to perform4 ,the soil must be considered not merely as the source of the inorganic food of plants1 for it has to act also as a support for them while growing1 and to retain a sufficient quantity of moisture to support their life2 and unless it possess the properties which fit it for this purpose1 it may contain all the elements of the food of plants1 and yet be nearly or altogether barren4 ,the adaptation of the soil to this function is dependent to a great extent on its mechanical texture1 and on this considerable light is frequently thrown by a kind of mechanical analysis4 ,if a soil be shaken up with water and allowed to stand for a few minutes1 it rapidly deposits a quantity of grains which are at once recognised as common sand2 and if the water be then poured off into another vessel and allowed to stand for a longer time1 a fine soft powder1 having the properties and composition of common clay1 is deposited1 while the clear fluid retains the soluble matters4 ,by a more careful treatment it is possible to distinguish and separate humus1 and in soils lying on chalk or limestone1 calcareous matter or carbonate of lime4 ,in this way the components can be classified into four groups1 a mixture of two or more of which in variable proportions is found in all soils4 ,the relative proportions in which these substances exist in soils are1 as we shall afterwards see1 the foundation of their classification into the light1 heavy1 calcareous1 and other sub-divisions4 ,but they are also intimately connected with certain chemical and mechanical peculiarities which have an important bearing on its fertility4 ,it is a familiar fact1 that particular soils are specially adapted to the growth of certain crops2 and we talk of a wheat or a turnip soil as readily distinguishable4 ,it is to be observed1 however1 that in many such instances the mere analysis may show no difference1 or1 at least1 none sufficient to account for the peculiarity4 ,a remarkable illustration is offered by the following analyses of two soils1 on one of which red clover grows luxuriantly1 while on the other it invariably fails4 ,clover fails4 ,clover succeeds4 ,insoluble silicates #hc4ij #ha4cd ,soluble silica #j4jh #j4jb ,peroxide of iron #d4de #f4fh ,alumina #b4dj #c4jj ,lime #a4bc #a4cc ,magnesia #j4de #j4be ,potash #j4bj #j4bb ,soda #j4jg #j4ji ,sulphuric acid #j4je #j4jh ,phosphoric acid #j4ch #j4jg ,carbonic acid #j4ji #j4cd ,chlorine trace trace ,humic acid #j4db #j4dc ,humine 444 #j4aj ,insoluble organic matters #c4gj #c4fa ,water #b4ed #b4eb ---- ---- #ii4if #ajj4jh ,nitrogen #j4ae #a4ae ,in this instance such difference as exists is rather in favour of the soil on which clover fails1 but it is exceedingly trifling2 and it is necessary to seek an explanation in the special properties of its mechanical constituents4 ,these properties are partly mechanical and partly chemical1 and in both ways exercise an important influence on the fertility of the soil4 ,sand and clay1 the most important of the mechanical constituents1 confer on the soil diametrically opposite properties2 the former1 when present in large quantity1 producing what are designated as light1 the latter stiff or heavy soils4 ,the hard indestructible siliceous grains1 of which sand is composed1 form a soil of an open texture1 through which water readily permeates2 while clay1 from its fine state of division1 and peculiar adhesiveness or plasticity1 gives it a close-textured and retentive character1 and their proper intermixture produces a light fertile loam1 each tempering the peculiar properties of the other4 ,indeed1 their mixture is manifestly essential1 for sand alone contains little or none of the essential ingredients of plants2 and if present in large quantity1 the openness of the soil is excessive1 water flows through it with rapidity1 manures are rapidly wasted1 and on the accession of drought1 the plants growing upon it soon languish and die4 ,clay1 on the other hand1 is by itself equally objectionable2 the closeness of its texture prevents the spreading of the roots of plants1 and the access of carbonic acid1 which1 as we have already seen1 is so important an agent in the changes occurring in the soil4 ,in fact1 a pure clay1 that is to say1 a clay unmixed with sand1 even though it may contain all the essential constituents of the plant1 is for this reason unfertile4 ,practically1 of course1 these extreme cases rarely occur2 the heaviest clay soils being mixtures of true clay with sand1 and the most sandy containing their proportion of clay2 but frequently the preponderance of the one over the other is so great1 as to produce soils greatly inferior to those in which the mixture is more uniform4 ,it is easy to understand how the proportions in which sand and clay are mixed must affect the suitability of soils to particular crops1 and that an open soil must be favourable to the turnip1 and a heavy clay1 owing to the resistance it offers to the expansion of the bulbs1 unfavourable4 ,but these substances also exercise an important chemical action on the soluble constituents of the food of plants1 combining with them1 and converting them into an insoluble1 or nearly insoluble state1 so as to prevent their being washed away by the rain or other water which percolates through the soil4 ,it has long been known to chemists that clay has a tendency to absorb a small proportion of ammonia1 and even when brought up from a great depth frequently contains that substance4 ,it is to ,mr4 ,thompson of ,moat ,hall1 however1 that we owe the important observation1 that arable soils rapidly remove ammonia from solution1 and ,way1 who pursued this investigation1 showed that not only ammonia1 but potash1 and several of the other important elements of the food of plants1 are thus absorbed4 ,the removal of these substances from solution is easily illustrated by a simple experiment4 ,it suffices to take a tall cylindrical vessel open at both ends1 and filled with the soil to be operated upon1 which is retained by a piece of rag tied over its lower end4 ,a quantity of a dilute solution of ammonia being then poured upon the surface of the soil1 and allowed to percolate1 the first quantity which flows away is found to have entirely lost its peculiar smell and taste2 and in a similar manner the removal of potash may be illustrated4 ,this action is by no means confined to those substances when in the free state1 but is equally marked when they are combined with acids in the form of salts1 and in the latter case the absorption is attended with a true chemical decomposition1 the base only being retained1 and the acid escaping most commonly in combination with lime4 ,thus1 if sulphate of ammonia be employed1 the water which flows from the soil contains sulphate of lime1 and if muriate of ammonia be used1 it is muriate of lime which escapes4 ,this absorbent action is most remarkably manifested in the case of ammonia and potash1 but it takes place also with magnesia and soda4 ,with the latter1 however1 it is incomplete1 only a half or a fourth of the soda being removed from solution1 the difference depending to some extent on the acid with which it is in combination4 ,the extent to which absorption takes place varies also with the nature of the soil1 and the state of combination of the substance used4 ,exact experiments have hitherto been chiefly confined to ammonia1 potash1 and lime in the free state1 and as bicarbonate2 and the following table gives the results obtained by ,way1 with solutions containing about #a per cent of these substances in solution3-- ---------------------------------------- ------------------------------------- ,loamy ,red soil1 ,pure ,subsoil soil1 ,berkshire4 clay4 clay1 ,dorsetshire4 ,somersetshire4 ---------------------------------------- --------------------------------- ,ammonia1 caustic #j4cdch #j4aegj 444 444 from muriate #j4cdgh #j4aiff #j4bhdg #j4jhah ,potash1 caustic 444 444 #a4jej #b4jhg from nitrate 444 444 #j4dihj 444 ,lime1 caustic 444 444 #a4dfh 444 from bicarbonate 444 444 #j4gca 444 ---------------------------------------- -------------------------------- ,from these numbers it appears that very great differences exist in the absorbent power of different soils1 the first of those experimented on being capable of taking more than twice as much ammonia as the second1 and nearly four times as much as the subsoil clay4 ,it appears also1 as far as absorption goes1 to be immaterial whether the ammonia is free or combined4 ,but it is different with potash1 which is absorbed from the nitrate to the extent of about ,o4#f per cent1 and from a caustic solution of potash to double that amount4 ,the circumstances under which absorption takes place modify1 in a manner which cannot well be explained1 the amount absorbed by the same soil4 ,it is found generally to be most complete with very dilute solutions1 and if a soil be agitated with a quantity of ammonia larger than it can take up1 it will absorb only a certain amount of that substance1 but by a further increase of the amount of ammonia a still larger quantity will be absorbed4 ,it is important to observe that when a salt is used1 the base only is absorbed1 and the acid escapes in combination with lime2 even nitric acid1 notwithstanding its importance as a food of plants1 being in this predicament4 ,from this it may be gathered that lime is not readily absorbed from solutions of its salts2 indeed1 it would appear that the only salt of that substance liable to absorption is the bicarbonate1 from which it is taken to the extent of #a4d per cent by the soil4 ,the absorption of lime from this salt1 and that of phosphoric acid1 which takes place to a considerable extent1 probably occurs1 however1 quite independently of the clay present in the soil1 and is occasioned by its lime1 which forms an insoluble compound with phosphoric acid1 and by removing half the carbonic acid of the bicarbonate of lime converts it also into an insoluble state4 ,in addition to these mineral substances1 organic matters are also removed from solution4 ,this is conspicuously seen in the case of putrid urine1 which not only loses its ammonia1 but also its smell and colour1 when allowed to percolate through soil2 and an equally marked result was obtained with flax water1 from which the organic matter was entirely abstracted4 ,the cause of this absorptive power is still very imperfectly known4 ,mr4 ,way having observed that sand has no such property1 while clay1 even when obtained from a considerable depth1 always possesses it1 supposed that the absorption was entirely due to that substance4 ,a difficulty1 however1 presents itself in explaining how it should happen that while a pure clay absorbs only #j4bhdg of ammonia1 a loamy soil1 of which one-half probably is sand1 should absorb a larger quantity4 ,the inference is1 that the effect cannot be due to the clay as a whole1 and ,mr4 ,way has sought to explain it by supposing that there exist in the soil particular double silicates of alumina and lime4 ,he has shown that felspar and the other minerals from which the soil is produced have no absorbent power1 but that artificial compounds can be formed which act upon solutions of ammonia and potash in a manner very similar to the soil2 but there is not the slightest evidence that these compounds exist in the soil1 and in the year #ahec;,i ,i pointed out the probability that clay is not the only agent at work1 but that the organic matters take part in the process4 ,so powerful indeed is the affinity of these substances for ammonia1 that chemists are at one as to the difficulty of obtaining humic and other similar acids pure1 owing to the obstinacy with which they retain it2 and there cannot be a doubt that in many soils these substances are in this point of view of much importance4 ,this is particularly the case in peat soils1 which1 though naturally barren1 may be made to produce good crops by the application of sand or gravel2 and as neither of these can cause any absorption of the valuable matters1 we must attribute this effect to the organic matter4 ,referring to an earlier series of experiments made in #ahej1 ,i showed that1 if a quantity of dry peat be taken and ammonia poured on it1 its smell disappears2 and this may be continued until upwards of #a4e per cent of dry ammonia has been absorbed1 and this quantity is retained by the peat4 ,in this case pure ammonia was used1 but ,way's experiments having shown that this alkali is not absorbed from its salts by organic matters1 ,i expressed the opinion that humate of lime 7which certainly exists in most soils7 ought on chemical grounds to decompose the salts of ammonia and cause the retention of their base4 ,the recent researches of ,brustlein have shown that lime does cause the organic matters to absorb ammonia from its salts4 ,he confirms the fact that pure ammonia is absorbed by peat1 and shows that decayed wood has the same effect1 although both are without action on solutions of its salts4 ,a stiff clay1 on the other hand1 containing organic matters and much carbonate of lime1 readily absorbed ammonia1 both when pure and combined2 but after extracting the lime by means of a dilute acid1 it lost the power of taking it from its salts1 although it retained the free alkali as completely as before4 ,on the addition of a small quantity of lime1 it again acquired the power of withdrawing ammonia from its compounds4 ,these experiments may be explained1 either on the supposition of the presence of humate of lime1 or by supposing that the carbonate of lime first decomposed the salts of ammonia1 and that the liberated alkali combined with the organic matter4 ,it must be admitted1 however1 that it is very doubtful whether the ammonia and other substances are fixed in the soil by a true chemical combination4 ,they are certainly retained by a very feeble attraction1 for it appears from ,brustlein's experiments that ammonia may be1 to a considerable extent1 removed by washing with abundance of water1 and that if the soil which has absorbed ammonia be allowed to become dry in the air1 it loses half its ammonia1 and after four times moistening and drying1 three-fourths have disappeared4 ,these facts are certainly not incompatible with the presence of a true chemical compound1 for the humate of ammonia is not absolutely insoluble1 and many cases occur of actions taking place in the presence of water1 which are entirely reversed when that fluid is removed2 and it is quite possible that when humate of ammonia is dried in contact with carbonate of lime1 it may be decomposed1 and carbonate of ammonia escape4 ,there are other circumstances1 however1 which render it1 on the whole1 most probable that the combination is not wholly chemical1 but rather of a physical character1 among which may be more especially mentioned the fact1 that the quantity of the substances retained by the soil is dependent on the degree of dilution of the fluid from which they are taken2 and that the quantity absorbed never exceeds a very small fraction of the weight of the soil4 ,the practical inferences to be drawn from these facts regarding the value of soils are of the highest importance4 ,it is obvious that two soils having exactly the same chemical composition may differ widely in absorptive power1 and that which possesses it most largely must have the highest agricultural value4 ,the examination of different soils1 in this point of view1 is a subject of much importance1 and deserves the best attention of both farmers and chemists1 although little has as yet been done in regard to it1 and the results which have been obtained are not of a very satisfactory character4 ,liebig states1 that in his experiments1 all the arable soils examined possessed the same absorptive power1 whether they contained a large or a small proportion of lime or alumina4 ,it can scarcely be expected1 however1 that this should be true in all cases1 and there are many facts which seem to indicate that differences must exist4 ,it is well known that there are some soils in which the manure is very rapidly exhausted1 and it is more than probable that this effect is due to deficient absorptive power1 which leaves the soluble matters at the mercy of the weather1 and liable at any moment to be washed out by a heavy fall of rain4 ,the more strictly mechanical properties of the soil1 such as its relations to heat and moisture1 are not less important than its chemical composition4 ,it is known that soils differ so greatly in these respects as sometimes materially to affect their productive capacity4 ,thus1 for instance1 two soils may be identical in composition1 but one may be highly hygrometric1 that is1 may absorb moisture readily from the air1 while the other may be very deficient in that property4 ,under ordinary circumstances no difference will be apparent in their produce1 but in a dry season the crop upon the former may be in a flourishing condition1 while that on the latter is languishing and enfeebled1 merely from its inability to absorb from the air1 and supply to the plant the quantity of water required for its growth4 ,in the same way1 a soil which absorbs much heat from the sun's rays surpasses another which has not that property2 and though in many cases this effect is comparatively unimportant1 in others it may make the difference between successful and unsuccessful cultivation in soils which lie in an unfavourable climate or exposure4 ,the investigation of the physical characters of soils has attracted little attention1 and we owe all our present knowledge of the subject to a very elaborate series of researches on this subject1 published by ,schuebler1 nearly thirty years ago4 ,he determined #ast1 ,the specific gravity of the soils2 #b;d1 ,the quantity of water which they are capable of imbibing2 #c;d1 ,the rapidity with which they give off by evaporation the water they have imbibed2 that is1 their tendency to become dry2 #dth1 ,the extent to which they shrink in drying2 #eth1 ,their hygrometric power2 #fth1 ,the extent to which they are heated by the sun's rays2 #gth1 ,the rapidity with which a heated soil cools down1 which indicates its power of retaining heat2 #hth1 ,their tenacity1 or the resistance they offer to the passage of agricultural implements2 #ith1 ,their power of absorbing oxygen from the air4 ,each of these experiments was performed on several different soils1 and on their mechanical constituents4 ,schuebler's experiments are undoubtedly important1 and though the methods employed are some of them not altogether beyond cavil1 they have apparently been performed with great care4 ,it is nevertheless desirable that they should be repeated1 for such facts ought not to rest on the authority of one experimenter1 however skilful and conscientious1 nor on a single series of soils1 which may not give a fair representation of their general physical properties4 ,in fact1 ,schuebler appears to imagine that having once determined the extent to which the sand1 clay1 and other mechanical constituents of the soil possess these properties1 we are in a condition to predicate the effect of their mixture in variable proportions1 although this is by no means probable4 ,in examining these properties1 ,schuebler selected for experiment1 pure siliceous sand1 calcareous sand 7carbonate of lime in coarse grains71 finely powdered carbonate of lime1 pure clay1 humus1 and powdered gypsum4 ,he used also a heavy clay consisting of #aa per cent of sand and #hi of pure clay1 a somewhat stiff clay containing #bd per cent of sand and #gf of clay1 a light clay with #dj per cent of sand and #fj of pure clay1 a garden soil consisting of #eb4d per cent of clay1 #cf4e of siliceous sand1 #a4h of calcareous sand1 #b per cent of finely divided carbonate of lime1 and #g4b of humus1 and two arable soils1 one from ,hoffwyl1 and one from a valley in the ,jura1 the former a somewhat stiff1 the latter a light soil4 ---------------------------------------- ----------------------- ,of #ajj parts of ,diminution ,water water in bulk absorbed absorbed during by #ajj there drying of ,specific parts evaporate #ajj parts gravity4 per cent4 in four moist hours soil at #ff deg4 ---------------------------------------- ----------------------- ,siliceous sand #b4gec #be #hh4d #j4j ,calcareous sand #b4hbb #bi #ge4i #j4j ,light clay #b4gja #dj #eb4j #f4j ,stiff clay #b4feb #ej #de4g #h4i ,heavy clay #b4fjc #fa #cd4i #aa4d ,pure clay #b4eia #gj #ca4c #ah4c ,carbonate of lime #b4dfh #he #bh4j #e4j ,humus #a4bbe #aij #bj4e #bj4j ,gypsum #b4ceh #bg #ga4g #j4j ,garden soil #b4ccb #if #bd4e #ad4i ,soil from ,hoffwyl #b4dja #eb #cb4j #ab4j ,soil from ,jura #b4ebf #dg #dj4a #i4e ---------------------------------------- ----------------------- ---------------------------------------- ---------------------------------- ,quantity ,power of of retaining hygrometric water absorbed heat4 by #gg4afe grains of the soil spread on ,calcareous a surface of #ada4dh square inches4 sand1 ---------------------------------------- -------------------- #ajj4 #ab hours4 #bd hours4 #dh hours4 #gb hours4 ---------------------------------------- --------------------------------- ,siliceous sand #j #j #j #j #ie4f ,calcareous sand #j4aed #j4bca #j4bca #j4bca #ajj4j ,light clay #a4fag #b4jjb #b4aef #b4aef #gf4i ,stiff clay #a4ibe #b4caj #b4fah #b4fie #ga4a ,heavy clay #b4caj #b4ggb #c4jhj #c4aeg #fh4d ,pure clay #b4hdi #c4bcd #c4fif #c4ggc #ff4g ,carbonate of lime #b4jjb #b4chg #b4fie #b4fie #fa4h ,humus #f4afj #g4dfi #h4dgj #i4bdj #di4j ,gypsum #j4jgg #j4jgg #j4jgg #j4jgg #gc4b ,garden soil #b4fie #c4dfe #c4hej #d4jjd #fd4h ,soil from ,hoffwyl #a4bcb #a4gga #a4gga #a4gga #gj4a ,soil from ,jura #a4jgh #a4dfc #a4edj #a4edj #gd4c ---------------------------------------- -------------------------------- ---------------------------------------- ------- ,quantity of oxygen absorbed by #gg4afe grains of the moist soil in #cj ,tenacity days1 from #ae of the cubic inches soils4 of atmospheric ,pure clay1 air4 #ajj4 ,expressed in cubic inches4 ---------------------------------------- ------ ,siliceous sand #j #j4bd ,calcareous sand #j #j4hd ,light clay #eg4c #a4ci ,stiff clay #fh4h #a4fe ,heavy clay #hc4c #b4jd ,pure clay #ajj4j #b4bi ,carbonate of lime #e4j #a4fb ,humus #h4g #c4jd ,gypsum #g4c #j4dj ,garden soil #g4f #b4fj ,soil from ,hoffwyl #cc4j #b4dc ,soil from ,jura #bb4j #b4be ---------------------------------------- ----------- ,the experiments detailed in the preceding table speak in a great measure for themselves1 and scarcely require detailed comment4 ,it may be remarked1 however1 that the columns illustrating the relations of the soil to water are probably more important than the others4 ,the superiority of a retentive over an open soil is sufficiently familiar in practice1 and though this is no doubt partly due to the former absorbing and retaining more completely the ammonia and other valuable constituents of the manures applied to it1 it is also dependent to an equal if not greater extent upon the power it possesses of retaining moisture4 ,a reference to the table makes it apparent that this power is presented under three different heads1 which are certainly related to one another1 but are not identical4 ,in the second column of the table is given the quantity of water absorbed by the soil1 determined by placing a given weight of the perfectly dry soil in a funnel1 the neck of which is partially stopped with a small piece of sponge or wool1 pouring water upon it1 and weighing it after the water has ceased to drop from it4 ,this may be considered as representing the quantity of water retained by these different soils when thoroughly saturated by long continued rains4 ,the column immediately succeeding gives the quantity of that water which escapes by evaporation from the same soil after exposure for four hours to dry air at the temperature of #ff deg44 ,the fifth1 sixth1 seventh1 and eighth columns indicate the quantity of moisture absorbed1 when the soil1 previously artificially dried1 is exposed to moist air for different periods4 ,these characters are dependent principally1 though not entirely1 on the porosity of the soil4 ,the last may also be in some measure due to the presence of particular salts1 such as common salt1 which has a great affinity for moisture1 but is chiefly occasioned by their peculiar structure4 ,it is to be remarked that clay and humus are two of the most highly hygrometric substances known1 and it is peculiarly interesting to observe1 that by a beneficent provision of nature1 they also form a principal part of all fertile soils4 ,the quantity of water imbibed by the soil is important to its fertility1 in so far as it prevents it becoming rapidly dry after having been moistened by the rains4 ,it is valuable also in another point of view1 because if the soil be incapable of absorbing much water1 it becomes saturated by a moderate fall of rain1 and when a larger quantity falls1 the excess of necessity percolates through the soil1 and carries off with it a certain quantity of the soluble salts4 ,important as this property is1 however1 it must not be possessed in too high a degree1 but must permit the evaporation of the water retained with a certain degree of rapidity4 ,soils which do not admit of this taking place are the cause of much inconvenience and injury in practice4 ,by becoming thoroughly saturated with moisture during winter1 they remain for a long time in a wet and unworkable condition1 in consequence of which they cannot be prepared and sown until late in the season1 and though chemically unexceptionable1 they are always disadvantageous1 and in some seasons greatly disappoint the hopes of the farmer4 ,the extent to which the imbibition and evaporation of water takes place is very variable1 but they are obviously related to one another1 the soils which absorb it least abundantly parting with it again with the greatest1 facility2 for it appears that siliceous sand absorbs only one-fourth of its weight of water1 and again gives off in the course of four hours four-fifths of that it had taken up1 while humus1 which imbibes nearly twice its weight1 retains nine-tenths of that quantity after four hours' exposure4 ,long-continued and slow evaporation of the water absorbed by a soil is injurious in another way1 for it makes the soil cold--a term of practical origin1 but which very correctly expresses the peculiarity in question4 ,it is due to the fact1 that when water evaporates it absorbs a very large quantity of heat1 which prevents the soil acquiring a sufficiently high temperature from the sun's rays4 ,the soils which have absorbed a large quantity of moisture shrink more or less in the process of drying1 and form cracks1 which often break the delicate fibres of the roots of the plants1 and cause considerable injury3 the extent of this shrinking is given in the fourth column4 ,the relation of the soils to heat divides itself into two considerations3 the amount of heat absorbed by the soil1 and the degree in which it is retained4 ,of these the latter only is illustrated in the table4 ,the former is dependent on so many special considerations1 that the results cannot be tabulated in a satisfactory manner4 ,it is independent of the chemical nature of the soil1 but varies to a great extent according to its colour1 the angle of incidence of the sun's rays1 and its state of moisture4 ,it is1 however1 an important character1 and has been found by ,girardin to exercise a considerable influence on the rapidity with which the crop ripens4 ,he found in a particular year that1 on the #beth of ,august1 #bf varieties of potatoes were ripe on a very dark-coloured sandy vegetable mould1 #bj on an ordinary sandy soil1 #ai on a loamy soil1 and only #af on a nearly white calcareous soil4 ,the tenacity of the soil is very variable1 and indicates the great differences in the amount of power which must be expended in working them4 ,according to ,schuebler1 a soil whose tenacity does not exceed #aj1 is easily tilled1 but when it reaches #dj it becomes very difficult and heavy to work4 ,on examining the table it becomes manifest1 that as far as its mechanical properties are concerned1 humus is a substance of the very highest importance1 for it confers on the soil1 in a high degree1 the power of absorbing and retaining water1 diminishes its tenacity and permits its being more easily worked1 adds to its hygrometric power and property of absorbing oxygen from the air1 and finally1 from its dark colour1 causes the more rapid absorption of heat from the sun's rays4 ,it will be thus understood1 that though it does not directly supply food to the plant1 it ministers indirectly in a most important manner to its well-being1 and that to so great an extent that it must be considered an indispensable constituent of a fertile soil4 ,but it is important to observe that it must not be present in too large a quantity1 for an excess does away with all the good effects of a smaller supply1 and produces soils notorious for their infertility4 ,such are the important physical properties of the soil1 and it is greatly to be desired that they should be more extensively examined4 ,the great labour which this involves has1 however1 hitherto prevented its being done1 and will1 in all probability1 render it impossible except in a limited number of cases4 ,some of these characters are1 however1 of minor importance1 and for ordinary purposes it might be sufficient to determine the specific gravity of the soil in the dry and moist state1 the power of imbibing and retaining water1 its hygrometric power1 its tenacity1 and its colour4 ,with these data we should be in a condition to draw probable conclusions regarding the others2 for the higher the specific gravity in the dry state1 the greater is the power of the soil to retain heat1 and the darker its colour the more readily does it absorb it4 ,the greater its tenacity the more difficult is it to work1 and the greater difficulty will the roots of the young plant find in pushing their way through it4 ,the greater the power of imbibing water1 the more it shrinks in drying2 and the more slowly the water evaporates1 the colder is the soil produced4 ,the hygrometric power is so important a character that ,davy and other chemists have even believed it possible to make it the measure of the fertility of a soil2 but though this may be true within certain limits1 it must not be too broadly assumed1 the results of recent experiments by no means confirming the opinion in its integrity1 but indicating only some relation between the two4 ,the ,subsoil4--,the term soil is strictly confined to that portion of the surface turned over by the plough working at ordinary depth2 which1 as a general rule1 may be taken at #aj inches4 ,the portion immediately subjacent is called the subsoil1 and it has considerable agricultural importance1 and requires a short notice4 ,in many instances1 soil and subsoil are separated by a purely imaginary line1 and no striking difference can be observed either in their chemical or physical characters4 ,in such cases it has been the practice with some persons not to limit the term soil to the upper portion1 but to apply it to the whole depth1 however great it may be1 which agrees in characters with the upper part1 and only to call that subsoil which manifestly differs from it4 ,this principle is perhaps theoretically the more correct1 but great practical advantages are derived from limiting the name of soil to the depth actually worked in common agricultural operations4 ,the subsoil is always analogous in its general characters to a soil1 but it may be either identical with that which overlies it or not4 ,of the former1 striking illustrations are seen in the wheat subsoils1 the analyses of which have been already given4 ,in the latter case great differences may exist1 and a heavy clay is often found lying on an open and porous sand1 or on peat1 and vice versa4 ,even where the characters of the subsoil appear the same as those of the soil1 appreciable chemical differences are generally observed1 especially in the quantity of organic matter1 which is increased in the soil by the decay of plants growing upon it and by the manure added4 ,in general1 then1 all that we have said regarding the characters of soils both chemically and physically1 will apply to the subsoils1 except that1 owing to the difficulty with which the air reaches the latter1 some minor peculiarities are observed4 ,the most important is the effect of the decay of vegetable matter1 without access of air1 which is attended by the reduction of the peroxide of iron to the state of protoxide1 and not unfrequently by the production of sulphuret of iron1 compounds which are extremely prejudicial to vegetation1 and occasionally give rise to some difficulties when the subsoil is brought to the surface1 as we shall afterwards have to notice4 ,the physical characters of the subsoil are often of much importance to the soil itself4 ,as1 for instance1 where a light soil lies on a clay subsoil1 in which case its value is much higher than if it reposed on an open or sandy subsoil4 ,and in many similar modes an important influence is exerted2 but these belong more strictly to the practical department of agriculture1 and need not be mentioned here4 ,classification of ,soils4--,numerous attempts have been made to form a classification of soils according to their characters and value1 but they have not hitherto proved very successful2 and the result of more recent chemical investigations has not been such as to encourage a farther attempt4 ,we have not at present data sufficient for the purpose1 nor1 if we had1 would it be possible to arrange any soil in its class except after an elaborate chemical examination4 ,the only classification at present possible must be founded on the general physical characters of the soil2 and the ordinary mode followed in practice of dividing them into clays1 loams1 etc4 etc41 which we need not here particularize1 fulfils all that can be done until we have more minute information regarding a large number of soils4 ,those of our readers who desire more full information on this point are referred to the works of ,thaer1 ,schuebler1 and others1 where the subject is minutely discussed4 ,,footnotes3 ,footnote ,i3 ,transactions of the ,highland and ,agricultural ,society1 vol4 vi41 p4 #cag4 ,,chapter ,,vi4 ,,the ,,improvement ,,of ,,the ,,soil ,,by ,,mechanical ,,processes4 ,comparatively few uncultivated soils possess the physical properties or chemical composition required for the production of the most abundant crops4 ,either one or more of the substances essential to the growth of plants are absent1 or1 if present1 they are deficient in quantity1 or exist in some state in which they cannot be absorbed4 ,such defects1 whether mechanical or chemical1 admit of diminution1 or even entire removal1 by certain methods of treatment1 the adaptation of which to particular cases is necessarily one of the most important branches of agricultural practice1 as the elucidation of their mode of action is of its theory4 ,the observations already made with regard to the characters of fertile soils must have prepared the reader for the statement that these defects may be removed1 either by mechanical or chemical processes4 ,the former method of improvement may at first sight appear to fall more strictly under the head of practical agriculture1 of which the mechanical treatment of the soil forms so important a part1 and that their improvement by chemical means should form the sole subject of our consideration in a treatise on agricultural chemistry4 ,but the line of demarcation between the mechanical and the chemical1 which seems so marked1 disappears on more minute observation1 and we find that the mechanical methods of improvement are frequently dependent on chemical principles2 and those which1 at first sight1 appear to be entirely chemical1 are also in reality partly mechanical4 ,it will be necessary for us1 therefore1 to consider shortly the mechanical methods of improving the soil4 ,draining4--,by far the most important method of mechanically improving the soil is by draining--a practice the beneficial action of which is dependent on a great variety of circumstances4 ,it is unnecessary to insist on the advantage derived from the rapid removal of moisture1 which enables the soil to be worked at times when this used to be almost impossible1 and other direct practical benefits4 ,of its more strictly chemical effects1 the most important is probably that which it produces on the temperature of the soil4 ,it has been already remarked that the germination of a seed is dependent on the soil in which it is sown acquiring a certain temperature1 and the rapidity of the after-growth of the plant is1 in part at least1 dependent on the same circumstance4 ,the necessary temperature is speedily attained by the heating action of the sun's rays1 when the soil is dry2 but when it is wet1 the heat is expended in evaporating the moisture with which it is saturated2 and it is only after this has been effected that it acquires a sufficiently high temperature to produce the rapid growth of the seeds committed to it4 ,the extent to which this effect occurs may be best illustrated by reference to some experiments made by ,schuebler1 in which he determined the temperature attained by different soils1 in the wet and dry state1 when exposed to the sun's rays1 from #aa till #c o'clock1 in the latter part of ,august1 when the temperature in the shade varied from #gc deg4 to #gg deg44 ------------------------------------- ,description of ,soil4 ,wet4 ,dry4 ------------------------------------- ,degs4 ,degs4 ,siliceous sand #ii4a #aab4f ,calcareous sand #ii4c #aab4a ,sandy clay #ih4b #aaa4d ,loamy clay #ii4a #aab4a ,stiff clay #ii4c #aab4c ,fine bluish-grey clay #ii4e #aac4j ,garden mould #ii4e #aac4e ,arable soil #ig4g #aaa4g ,slaty marl #aja4h #aae4c ------------------------------------- ,in a soil which is naturally dry or has been drained1 the superfluous moisture escapes by the drains1 and only that comparatively small quantity which is retained by capillary attraction is evaporated1 and hence the soil is more frequently and for a longer period in a condition to take advantage of the heating effect of the sun's rays1 and in this way the period of germination1 and1 by consequence also1 that of ripening is advanced4 ,the extent of this influence is necessarily variable1 but it is generally considerable1 and in some districts of ,scotland the extensive introduction of draining has made the harvest1 on the average of years1 from ten to fourteen days earlier than it was before4 ,it is unnecessary to insist on the importance of such a change1 which in upland districts may make cultivation successful when it was previously almost impossible4 ,the removal of moisture by drainage affects the physical characters of the soil in another manner2 it makes it lighter1 more friable1 and more easily worked2 and this change is occasioned by the downward flow of the water carrying with it to the lower part of the soil the finer argillaceous particles1 leaving the coarser and sandy matters above1 and in this way a marked improvement is produced on heavy and retentive clays4 ,the access of air to the soil is also greatly promoted by draining4 ,in wet soils the pores are filled with water1 and hence the air1 which is so important an agent in their amelioration1 is excluded2 but so soon as this is removed1 the air is enabled to reach and act upon the organic matters and other decomposable constituents present4 ,in this way also provision is made for the frequent change of the air which permeates the soil2 for every shower that falls expels from it a quantity of that which it contains1 and as the moisture flows off by the drains1 a new supply enters to take its place1 and thus the important changes which the atmospheric oxygen produces on the soil are promoted in a high degree4 ,the air which thus enters acts on the organic matters of the soil1 producing carbonic acid1 which we have already seen is so intimately connected with many of its chemical changes4 ,in its absence the organic matters undergo different decompositions1 and pass into states in which they are slowly acted on1 and are incapable of supplying a sufficient quantity of carbonic acid to the soil2 and they thus exercise an action on the peroxide of iron1 contained in all soils1 reduce it to the state of protoxide1 or1 with the simultaneous reduction of the sulphuric acid1 they produce sulphuret of iron1 forms of combination which are well known to be most injurious to vegetation4 ,the removal of water from the lower part of the soil1 and the admission of air1 which is the consequence of draining1 submits that part of it to the same changes which take place in its upper portion1 and has the effect of practically deepening the soil to the extent to which it is thus laid dry4 ,the roots of the plants growing on the soil1 which stop as soon as they reach the moist part1 now descend to a lower level1 and derive from that part of it supplies of nourishment formerly unavailable4 ,the deepening of the soil has further the effect of making the plants which grow upon it less liable to be burned up in seasons of drought1 a somewhat unexpected result of making a soil drier1 but which manifestly depends on its permitting the roots to penetrate to a greater depth1 and so to get beyond the surface portion1 which is rapidly dried up1 and to which they were formerly confined4 ,it may be added also that the abundant escape of water from the drains acts chemically by removing any noxious matters the soil may contain1 and by diminishing the amount of soluble saline matters1 which sometimes produce injurious effects4 ,it thus prevents the saline incrustation frequently seen in dry seasons on soils which are naturally wet1 and which is produced by the water rising to the surface by capillary attraction1 and1 as it evaporates1 depositing the soluble substances it contained1 as a hard crust which prevents the access of air to the interior of the soil4 ,it is thus obvious that the drainage of the soil modifies its properties both mechanically and chemically4 ,it exerts also various other actions in particular cases which we cannot here stop to particularize4 ,it ameliorates the climate of districts in which it is extensively carried out1 and even affects the health of the population in a favourable manner4 ,the sum of its effects must necessarily differ greatly in different soils1 and in different districts2 but a competent authority,j has estimated1 that1 on the average1 land which has been drained produces a quarter more grain per acre than that which is undrained4 ,but this by no means exhausts the benefits derived from it1 draining being merely the precursor of further improvement4 ,it is only after it has been carried out that the farmer derives the full benefit of the manures which he applies4 ,he gains also by the increased facility of working the soil1 and by the rapidity with which it dries after continued rain1 thus enabling him to proceed at their proper season with agricultural operations1 which would otherwise have to be postponed for a considerable time4 ,it would be out of place to enlarge here upon the mode in which draining ought to be carried out2 it may be remarked1 however1 that much inconvenience and loss has occasionally been produced by too close adherence to particular systems4 ,no rules can be laid down as to the depth or distance between the drains which can be universally applicable1 but the intelligent drainer will seek to modify his practice according to the circumstances of the case4 ,as a general rule1 the drains ought to be as deep as possible1 but in numerous instances it may be more advantageous to curtail their depth and increase their number4 ,if1 for instance1 a thick impervious pan resting on a clay were found at the depth of three feet below the surface1 it would serve no good purpose to make the drains deeper2 but if the pan were thin1 and the subjacent layer readily permeable by water1 it might be advantageous to go down to the depth of four feet1 trusting to the possible action of the air which would thus be admitted1 gradually to disintegrate the pan1 and increase the depth of soil above it4 ,it is a common opinion that if we reach1 at a moderate depth1 a tenacious and little permeable clay1 no advantage is obtained by sinking the drains into it2 but this is an opinion which should be adopted with caution1 both because no clay is absolutely impermeable1 even the most tenacious permitting to a certain extent the passage of water1 and because the clay may have been brought down by water from the upper part of the soil1 and may have stopped there merely for want of some deeper escape for the water1 and which drains at a lower level might supply4 ,in some cases it may even be advisable to vary the depth of the drains in different parts of the same field1 and the judicious drainer may sometimes save a considerable sum by a careful observation of the peculiarities of the different parts of the ground to be drained4 ,subsoil and ,deep ,ploughing4--,it frequently happens1 when a soil is drained1 that the subsoil is so stiff as to permit the passage of water imperfectly1 and to prevent the tender roots of the plant from penetrating it1 and reaching the new supplies of nourishment which are laid open to them4 ,in such cases the benefits of subsoil ploughing and deep ploughing are conspicuous4 ,the mode of action of these two methods of treatment is similar but not identical4 ,the subsoil plough merely stirs and opens the subsoil1 and permits the more ready passage of water and the access of air and of the roots of plants--the former to effect the necessary decompositions1 the latter to avail themselves of the valuable matters set free4 ,but deep ploughing produces more extensive changes2 it raises new soil to the surface1 mixes it with the original soil1 and thus not only brings up fresh supplies of valuable matters to it1 but frequently changes its chemical and mechanical characters1 rendering a heavy soil lighter by the admixture of a light subsoil1 and vice versa4 ,both are operations which are useless unless they are combined with draining1 for it must manifestly serve no good purpose to attempt to open up a soil unless the water which lies in it be previously removed4 ,in fact1 subsoiling is useless unless the subsoil has been made thoroughly dry2 and it has been found by experience that no good effects are obtained if it be attempted immediately after draining1 but that a sufficient time must elapse1 in order to permit the escape of the accumulated moisture1 which often takes place very slowly4 ,without this precaution1 the subsoil1 after being opened by the plough1 soon sinks together1 and the good effects anticipated are not realized4 ,the necessity for allowing some time to elapse between draining and further operations is still more apparent in deep ploughing1 when the soil is actually brought to the surface4 ,in that case it requires to be left for a longer period after draining1 in order that the air may produce the necessary changes on the subsoil2 for if it be brought up after having been for a long time saturated with moisture1 and containing its iron as protoxide1 and the organic matter in a state in which it is not readily acted upon by the air1 the immediate effect of the operation is frequently injurious in place of being advantageous4 ,one of the best methods of treating a soil in this way is to make the operation a gradual one1 and by deepening an inch or two every year gradually to mix the soil and subsoil2 as in this way from a small quantity being brought up at a time no injurious effects are produced4 ,deep ploughing may be said to act in two ways1 firstly1 by again bringing to the surface the manures which have a tendency to sink to the lower part of the soil1 and1 secondly1 by bringing up a soil which has not been exhausted by previous cropping--in fact a virgin soil4 ,the success which attends the operation of subsoiling or deep ploughing must manifestly be greatly dependent on the character of the subsoil1 and good effects can only be obtained when its chemical composition is such as to supply in increased quantity the essential constituents of the plant2 and it is no doubt owing to this that the opinions entertained by practical men1 each of whom speaks from the results of his own experience1 are so varied4 ,the effects produced by deep ploughing on the estates of the ,marquis of ,tweeddale1 are familiarly known to most ,scottish agriculturists1 and they are at once explained by the analyses of the soil and subsoil here given1 which show that the latter1 though poor in some important constituents1 contains more than twice as much potash as the soil4 ,soil4 ,subsoil4 ,insoluble silicates #hg4fbc #hb4gb ,soluble silica #j4cic #j4ab ,alumina and peroxide of iron #d4abi #h4fj ,lime #j4cda #j4ah ,magnesia #j4bij #j4bd ,sulphuric acid #j4jbg #j4jc ,phosphoric acid #j4bdj trace ,potash #j4jeb #j4ab ,soda #j4jej #j4jd ,water #a4ief #c4bf ,organic matter #e4bbj #d4jb ------ ----- #ajj4cba #ii4cc ,in addition to the difference in the amount of potash1 something is probably due to the large proportion of alumina and oxide of iron in the subsoil1 which for this reason must be more tenacious than the soil itself1 which appears to be rather light4 ,in other instances1 the use of the subsoil plough has occasioned much disappointment1 and has led to its being decried by many practical men2 but of late years its use having become better understood1 its merits are more generally admitted4 ,we believe1 that in all cases in which the soil is deep1 more or less marked good effects must be produced by its use1 but of course there must be cases in which1 from the defective composition of the subsoil or other causes1 it must fail4 ,it may sometimes be possible a priori to detect these cases1 but in a large majority of them our knowledge is still too limited to admit of satisfactory conclusions being arrived at4 ,improving the ,soil by ,paring and ,burning4--,it has long been familiarly known1 that a decided improvement has been produced on some soils by burning4 ,its advantages have chiefly been observed on two sorts1 heavy clays and peat soils1 on both of which it has been practised to a great extent4 ,the action of heat on the heavy clays appears to be of a twofold character1 depending partly on the change effected in its physical properties1 and partly on a chemical decomposition produced by the heat4 ,the operation of burning is effected by mixing the clay with brushwood and vegetable refuse1 and allowing it to smoulder in small heaps for some time4 ,it is a process of some nicety1 and its success is greatly dependent on the care which has been taken to keep the temperature as low as possible during the whole course of the burning4 ,experience has shown that burning is by no means equally advantageous to all clays1 but is most beneficial on those containing a considerable quantity of calcareous matter1 and of silicates of potash4 ,in such clays heat operates by causing the lime to decompose the alkaline silicates1 and liberate a quantity of the potash which was previously in an unavailable state4 ,its effect may be best illustrated by the following analyses by ,dr4 ,voelcker of a soil1 and the red ash produced in burning it4 ,soil4 ,red ,ash4 ,water #j4ic #a4ah ,organic matter #aj4fg #c4cb ,oxides of iron and alumina #ac4dj #ah4db ,carbonate of lime #bc4ij #h4hc ,sulphate of lime trace #a4ae ,carbonate of magnesia #a4aj ,magnesia #a4gf ,phosphoric acid trace #j4ga ,potash #j4ch #a4jh ,soda #j4ac ,chloride of sodium #a4jc ,insoluble matter1 chiefly clay #di4ff #fb4eb ----- ----- #ajj4ag #ajj4jj ,in this instance the quantity of burned soil amounted to about fifteen tons per acre1 and it is obvious that the quantity of potash which had been liberated from the insoluble clay and the phosphoric acid are equal to that contained in a considerable manuring4 ,in order to obtain these results1 it is necessary1 as has been already observed1 to keep the temperature as low as possible during the process of burning1 direct experiment having shown that when this precaution is not observed another change occurs1 whereby the potash1 which at low temperatures becomes soluble1 passes again into an insoluble state4 ,a part of the beneficial effect is no doubt also due to the change produced in the physical characters of the clay by burning1 which makes it lighter and more friable1 and by mixture with the unburnt clay ameliorates the whole4 ,this improvement in the physical characters of the clay also requires that it shall be burnt with as low a heat as possible2 for if it rises too high1 the clay coheres into hard masses which cannot again be reduced to powder1 and the success of the operation of burning may always be judged of by the readiness with which it falls into a uniform friable powder4 ,the improvement of peat by burning has been practised to some extent in ,scotland1 though less frequently of late years than formerly2 but it is still the principal method of reclaiming peat soils in many countries1 and particularly in ,finland1 where large breadths of land have been brought into profitable cultivation by means of it4 ,the modus operandi of burning peat is very simple2 it acts by diminishing the superabundant quantity of humus or other organic matters1 which1 in the previous section we have seen to be so injurious to the fertility of the soil4 ,it may act also in the same way as it does on clay1 by making part of the inorganic constituents more really soluble1 although it is not probable that its effect in this way can be very marked4 ,its chief action is certainly by destroying the organic matters1 and by thus improving the physical character of the peat1 and causing it to absorb and retain a smaller quantity of water than it naturally does4 ,for this reason it is that it proves successful only on thin peat bogs1 for if they be deep1 the inorganic matters soon sink into the lower part1 and the surface relapses into its old state of infertility4 ,it is probably for this reason that the practice has been so much abandoned in ,scotland1 more especially as other and more economical modes of treating peat soils have come into use4 ,warping4--,this name has been given to a method of improving soils by causing the water of rivers to deposit the mud it carries in suspension upon them1 and which has been largely practised in the low lying lands of ,lincoln and ,yorkshire1 where it was introduced about a century ago4 ,it is most beneficial on sandy or peaty soil1 and by its means large tracts of worthless land have been brought under profitable cultivation4 ,it requires that the land to be so treated shall be under the level of the river at full tide1 and it is managed by providing a sluice through which the river water is allowed to flood the land at high tide1 and again to escape at ebb1 leaving a layer of mud generally about a tenth of an inch in thickness1 which it brought along with it4 ,by the repetition of this process1 a layer of several feet in thickness1 of an excellent soil1 is accumulated on the surface4 ,herapath1 who has carefully examined this subject chemically1 has shown that in one experiment where the water used contained #bcc grains of mud per gallon1 #baj were deposited during the warping4 ,the following analyses will show the general nature of the matters deposited1 and the change which they produce on the soil3--,no4 #a is the mud from the ,humber in its natural state1 ,no4 #b a specimen of warp of average quality artificially dried1 ,no4 #c a sandy soil before warping1 and ,no4 #d1 the same fifteen years after having received a coating of #aa inches of mud4 ---------------------------------------- --------------------------- #a #b #c #d ---------------------------------- ,water #dg4di 444 #a4jf #b4jj ,organic matter #e4id #f4ic #b4bj #g4fa ,chloride of ,calcium 444 444 444 444 ,magnesium 444 #j4aj 444 444 ,sodium #a4ff #j4id #j4ad #j4af ,potassium ,sulphate of ,soda 444 #j4ca 444 444 ,magnesia 444 #a4ah 444 444 ,lime trace #a4aj trace trace ,carbonate of ,magnesia #b4fj #j4ca trace #j4bi ,lime #c4ei #h4ah trace #j4df ,potash and ,soda #j4ah #j4dg trace #j4ag ,magnesia #a4fi #b4fj trace #j4bf ,lime #j4ci #j4fh trace #j4ad ,peroxide of ,iron #f4fc #e4je #j4jh #a4ag ,alumina #h4ah #j4ci #j4da ,phosphate of ,iron #j4eh #a4jd trace #j4bh ,silica 444 #i4je #j4ad #b4gg ,sand and ,stones #bi4ae #ee4hg #ie4ia #hd4ig ---------------------------------- #ajj4jj #ajj4jj #ajj4jj #ajj4jj ---------------------------------------- --------------------------- ,it is easy to understand the importance of the effects produced by adding to any soil large quantities of a mud containing upwards of one per cent of phosphate of iron2 and in point of fact1 ,herapath has calculated that in one particular instance the quantity of phosphoric acid brought by warping upon an acre of land1 exceeded seven tons per acre4 ,as1 moreover1 the matters are all in a high state of division1 they must exist in a condition peculiarly favourable to the plant4 ,the overflow of the ,nile is only an instance of warping on the large scale1 with this difference1 that it is repeated once only in every year1 whereas1 in this country1 the operation is repeated at every tide until a deposit sometimes of several feet in thickness is obtained1 after which it is stopped1 and the soil brought under ordinary cultivation4 ,an operation which is1 in some respects1 the converse of warping1 has been carried out on ,blair-,drummond ,moss1 where the peat has been dislodged and carried off by the action of water1 leaving the subjacent soil in a state fitted for cropping4 ,of course both this and warping are restricted to special localities1 but they are most important means of ameliorating the soil when circumstances admit of their being carried out4 ,mixing of ,soils4--,when soils possess conspicuous defects in their physical1 and even in their chemical properties1 great advantages may1 in some instances1 be derived from their proper admixture4 ,a light sandy soil1 for instance1 is greatly improved by the addition of clay1 and vice versa2 so that1 when two soils of opposite properties occur near to one another1 both may be improved by mixture4 ,it has been applied to the improvement of heavy clay soil and of peat1 the former being mixed with sand or marl so as to diminish its tenacity2 the latter with clay or gravel to add to its inorganic matters1 and in both instances it has proved successful4 ,the process of chalking1 which has been carried out on a large scale in some parts of ,england1 and which consists in bringing up the chalk from pits1 penetrating through the overlying tenacious clay1 and mixing it with the soil1 operates1 to some extent1 in a similar manner1 though no doubt the lime also exercises a strictly chemical action4 ,it is probable that the mixing of soils might be advantageously extended1 and it merits more minute study than it has yet obtained4 ,its use is obviously limited by the expense1 because1 of course1 where good effects are to be obtained1 it is necessary to remove large quantities of soil1 in some instances as much as #ej or #ajj tons per acre1 but the expense might be much diminished if it were carried out methodically1 and on a considerable scale4 ,the admixture of highly fertile soils with others of inferior quality is also worthy of attention2 indeed1 it is understood that this has been done1 to some extent1 with the rich trap soils of some parts of ,scotland1 but the extent of the benefit derived from it has not been made public4 ,,footnotes3 ,footnote ,j3 ,mr4 ,dudgeon1 ,spylaw4 ,transactions of the ,highland ,society1 vol4 cxxix41 p4 #eje4 ,,chapter ,,vii4 ,,the ,,general ,,principles ,,of ,,manuring4 ,in their natural condition all soils not absolutely barren are capable of supporting a certain amount of vegetation1 and they continue to do so for an unlimited period1 because the whole of the substances extracted from them are again restored1 either directly by the decay of the plants1 or indirectly by the droppings of the wild animals which have browzed upon them4 ,under these circumstances1 a soil yields what may be called its normal produce1 which varies within comparatively narrow limits1 according to the nature of the season1 temperature1 and other climatic conditions4 ,but the case is completely altered if the crop1 in place of being allowed to decay on the soil1 is removed from it1 for1 though the air will continue to afford an undiminished supply of those elements of the food of plants which may be derived from it1 the fixed substances1 which can only be obtained from the soil1 decrease in quantity1 and are at length entirely exhausted4 ,in this way a gradual diminution of the fertility of the soil takes place1 until1 after the lapse of a period1 longer or shorter1 according to its natural resources1 it will become entirely incapable of maintaining a crop1 and fall into absolute infertility unless the substances removed from it are restored from some other source in the form of manure4 ,when this is done1 the fertility of the soil may not only be sustained but greatly increased1 and1 in point of fact1 all cultivated soils1 by the use of manure1 are made to yield a much larger crop than they can do in their natural condition4 ,the fundamental principle upon which a manure is employed is that of adding to the soil an abundant supply of the elements removed from it by plants in the condition best fitted for absorption by their roots2 but looked at in its broadest point of view1 it acts not merely in this way1 but also by promoting the decomposition of the already partially disintegrated rocks of which the soil is composed1 setting free those substances it already contains1 and facilitating their absorption by the plants4 ,in considering the practical applications of the broad general principle just stated1 it might be assumed that a manure ought invariably to contain all the elements of plants in the quantities in which they are removed by the crops1 and that when this has been accurately ascertained by analysis1 it would only be necessary to use the various substances in the proportions thus indicated4 ,but this1 though a very important1 and no doubt in many cases essential condition1 is by no means the only matter which requires to be taken into consideration in the economical application of manures4 ,and this becomes sufficiently obvious when the circumstances attending the exhaustion of the soil are minutely examined4 ,when a soil is cropped during a succession of years with the same plant1 and at length becomes incapable of longer maintaining it1 the exhaustion is rarely1 if ever1 due to the simultaneous consumption of all its different constituents1 but generally depends upon that of one individual substance1 which1 from its having originally existed in the soil in comparatively small quantity1 is removed in a shorter time than the others4 ,to restore the fertility of a soil in this condition1 it is by no means necessary to supply all the different substances required by the plant1 for it will suffice to add that which has been entirely removed4 ,on the other hand1 if an ordinary soil be supplied with a manure containing a very small quantity of one of the elements of plant food1 along with abundance of all the others1 the amount of increase which it yields must obviously be measured1 not by those which are abundant1 but by that which is deficient2 for the crop which grows luxuriantly so long as it obtains a supply of all its constituents1 is arrested as effectually by the want of one as of all1 as has been proved by the experiments of ,prince ,salm ,horstmar and others1 referred to in a previous chapter2 and hence1 in order to obtain a good crop1 it would be necessary to use the manure in such abundance as to supply a sufficiency of the deficient element for that purpose4 ,if this course were persevered in for a succession of years1 the other substances which would have been used in much more than the quantity required by the crops1 must either have been entirely lost or have accumulated in the soil4 ,in the latter case it is sufficiently obvious that the soil must have been gradually acquiring an amount of resources which must remain dormant until the system of manuring is changed4 ,to render them available1 it is only necessary to add to it a quantity of the particular substance in which the manure hitherto employed has been deficient1 so as to restore the lost balance1 and enable the plant to make use of those which have been stored up within it4 ,the substance so used is called a special manure2 that containing all the constituents of the crop is a general manure4 ,the distinction of these two classes of manures is very important in a practical point of view1 because a special manure is not by itself capable of maintaining the life of plants1 but is only a means of bringing into use the natural and acquired resources of the soil4 ,in place of preventing or retarding its exhaustion1 it rather accelerates it by causing the increased crops to consume more abundantly1 and within a shorter period of time1 those substances which it contains4 ,on the other hand1 a general manure prevents or diminishes the consumption of the elements of plant-food contained in the soil1 and if added in sufficient abundance1 may cause them to accumulate in it1 and even enable an almost absolutely barren soil to yield a tolerable crop4 ,general manures must therefore always be the most important and essential1 and no others would be used if it were possible to obtain them of a composition exactly suited to the requirements of the crop to be raised4 ,practically1 however1 this condition cannot be fulfilled1 because all the substances available for the purpose1 and particularly farm-yard manure1 are refuse matters1 the exact composition of which is not under our control1 and they do not necessarily contain their constituents either in the most suitable proportions1 or the most available forms1 and consequently when they are used during a succession of years1 certain of their constituents may accumulate in the soil1 and it is under such circumstances that special manures are both necessary and advantageous4 ,several different substances1 but more especially farm-yard manure1 fulfil in a very remarkable manner the conditions of a general manure1 and supply abundantly1 not merely the mineral1 but also the carbonaceous and nitrogenous matters necessary for building up the organic part of the plant2 and hence its use is governed by principles of comparative simplicity1 and really resolves itself into determining the best mode of managing it so as effectually to preserve its useful constituents1 and1 at the same time1 to bring them into those forms of combination in which they are most available to the plant4 ,but the employment of a special manure opens up nice questions as to the relative importance of the different elements of plants which have given rise to much controversy and difference of opinion4 ,in treating of the food of plants1 it has been already observed that the fixed or mineral constituents which are contained in their ash1 are necessarily derived exclusively from the soil1 but that the carbon1 hydrogen1 nitrogen1 and oxygen1 of which their organic part is composed1 may be obtained either from that source or from the air4 ,the important distinction which thus exists between these two classes of substances1 has given rise to two different views regarding the theory of manures4 ,basing his views on the presence of the organic elements in the air1 ,liebig has maintained that it is unnecessary to supply them in the manure1 while others1 among whom ,messrs4 ,lawes and ,gilbert have taken a prominent position1 hold that1 as a rule1 fertile soils1 cultivated in the ordinary manner1 contain a sufficient supply of mineral matters for the production of the largest possible crops1 but that the quantity of ammonia and nitric acid which the plants are capable of extracting from the air is insufficient1 and must be supplemented by manures containing them4 ,a large number of experiments have been made in support of these views1 but the inferences which can be drawn from them are not absolutely conclusive on either side1 and it is necessary to consider the matter in a general point of view4 ,setting out from the proposition already so frequently referred to1 that the plant cannot grow unless it receives a supply of all its elements1 it must be obvious that if1 to a soil containing a sufficiency of mineral matters to raise a given number of crops1 a supply of ammonia be added1 its total productive capacity cannot be thus increased2 and though it may yield larger crops than it would have done without that substance1 this can only be accomplished by a proportionate diminution of their number4 ,in either case1 the same quantity of vegetable matter will be produced1 but the time within which it is obtained will be regulated by the supply of ammonia4 ,that substance differs in no respect from any other element of plant-food1 and used in this way is to all intents and purposes a special manure1 and acts merely by bringing into play those substances which the soil already contains4 ,its effect may not be apparent until after the lapse of a very long period of time1 but it ultimately leads to the exhaustion of the soil4 ,if1 on the other hand1 a soil be continuously cropped until it ceases to yield any produce1 it is manifest that the exhaustion must in this instance be entirely due to the removal of its available mineral nutriment1 because the superincumbent air constantly changed by the winds must continue to afford the same unvarying supply of the organic elements1 and the power of supporting vegetation would be restored to it1 by adding the necessary inorganic matters4 ,hence when a soil1 which in its natural condition is capable of yielding a certain amount of vegetable matter1 is rendered barren by the removal of the crop1 it may be laid down as an incontrovertible position1 that its infertility is due to the loss of mineral matters1 and that it may be restored to its pristine condition by the use of them1 and of them only4 ,but the case is materially altered when we come to consider the course of events in a cultivated soil4 ,the object of agriculture is to cause the soil1 by appropriate treatment1 to yield much more than its normal produce1 and the question is1 how this can be best and most economically effected in practice4 ,according to ,liebig1 it is attained by adding to the soil a liberal supply of those mineral substances required by the plant1 and that it is unnecessary to use any of the organic elements1 because they are supplied by the air in sufficient quantity to meet the requirements of the most abundant crops4 ,other chemists and vegetable physiologists again hold that though a certain increase may be obtained in this way1 a point is soon reached beyond which mineral matters will not cause the plant to absorb more ammonia from the air1 although a further increase may be obtained by the addition of nitrogen in that or some other available form4 ,it is admitted on both sides1 that all the elements of plant food are equally essential1 and the controversy really lies in determining what practically limits the crop producible on any soil4 ,the point at issue may be put in a clear point of view by considering the course of events on a soil altogether devoid of the elements of plants4 ,if a small quantity of mineral matters be added to such a soil1 it immediately becomes capable of supporting a certain amount of vegetation1 deriving from the air the organic elements necessary for this purpose1 and with every increase of the former1 the air will be laid under a larger contribution of the latter1 to support the increased growth1 and this must proceed until the limit of supply from the atmosphere is reached4 ,at this point a further supply of mineral matters alone must obviously be incapable of again increasing the crop1 and it would thus be absolutely necessary to conjoin them with a proportionate quantity of organic substances4 ,liebig maintains that this limit is never attained in practice1 but that the air affords ammonia and the other organic elements in excess of the requirements of the largest crop1 while mineral matters are generally though not invariably present in the soil in insufficient quantity4 ,messrs4 ,lawes and ,gilbert1 on the other hand1 believe that the soil generally contains an excess of mineral matters1 and that a manure which is to bring out their full effect must contain ammonia1 or some other nitrogenous substance fitted to supplement the deficient supply afforded by the atmosphere4 ,in short1 the question at issue is1 whether there is or is not a sufficiency of atmospheric food to meet the demands of the largest crop which can practically be produced4 ,an absolutely conclusive reply to this question is by no means easy4 ,the experiments by which it is to be resolved are complicated by the fact1 that all soils capable of supporting anything like a crop1 contain not only the mineral1 but the organic elements of its food in large and generally in greatly superabundant quantity1 and it is impossible satisfactorily to ascertain how much is derived from this source1 and how much from the atmosphere4 ,there are in fact no experiments in which the effects of a purely mineral soil have been ascertained4 ,the important and carefully performed researches of ,messrs4 ,lawes and ,gilbert were made upon a soil which had been long under cultivation1 and contained decaying vegetable matters in sufficient abundance to supply nitrogen to many successive crops1 and it would be most unreasonable to assert that the produce they did obtain by means of mineral manures1 drew the whole of its nitrogen from the air4 ,on the contrary1 it may be fairly assumed that the soil did yield a certain quantity of its nitrogenous compounds1 but to what extent this occurs1 it is impossible to determine4 ,this difficulty is encountered more or less in all the other experiments1 and precludes absolute conclusions4 ,the same fallacy also besets the arguments of ,liebig when he holds that the crop1 increased by means of mineral manures alone1 must derive the whole of the additional quantity of nitrogen which it contains from the air1 as appears to be tacitly assumed throughout the whole discussion4 ,so far from this being the case1 it is just as likely that the mineral matters should cause the plants to take it from the soil1 if it is there1 as from the atmosphere4 ,taking a general view of the whole question1 it is evident that a certain amount of vegetation may always be produced by means of mineral manures1 and the quantity obtained is generally much beyond the normal produce of the soil4 ,but it is still open to doubt whether the largest possible crop can be thus obtained1 although the balance of evidence is against it1 and in favour of the addition of ammonia1 and other nitrogenous and organic substances1 to the soil4 ,in actual practice manures containing nitrogen are more important1 and more extensively applied than any others1 and the quantity of that element thus used is very much larger than is generally supposed4 ,twenty tons of farm-yard manure1 a quantity commonly applied1 and often exceeded on well cultivated land1 contain a sufficiency of organic matters to yield about #b-a_/b cwt4 of nitrogen4 ,a complete rotation1 according to the six-course shift1 contains almost exactly the same quantity of nitrogen1 when we assume average crops throughout the whole1 and it is thus made up4,k ,lbs4 of ,nitrogen4 #a4 ,turnips 7#ac-a_/b tons7 #fj #b4 ,wheat 7#bh bushels at #fj lbs47 #bi ,straw #af #c4 ,hay 7#b-a_/b tons7 #ef #d4 ,oats 7#cd bushels at #dj lbs47 #bg ,straw #ad #e4 ,potatoes 7#c tons7 #bg #f4 ,wheat and straw as before #de ---- ,total #bgd ,the supply is therefore quite sufficient for the requirements of the crop2 and when it is borne in mind that a considerable quantity of ammonia and nitric acid is annually carried down by the rain1 and that during a long rotation other substances are very generally used in addition to farm-yard manure1 it is obvious that the crop need not depend to any extent upon what it derives from the air4 ,what is true of the nitrogenous matters applies with still greater force to the mineral constituents of the manure4 ,twenty tons of farm-yard manure contain #cb cwt4 of mineral matters1 while the average crops of a six course-shift contain only #ajhh lbs41 or less than one-third of this quantity4 ,it is obvious1 therefore1 that in well manured land there must be a gradual increase of all the constituents of plants1 but that of the mineral matters is relatively much greater than that of the nitrogenous4 ,if therefore from any cause the crop produced on a soil to which farm-yard manure had been applied were greatly to exceed the average1 the amount of produce1 so far as the soil is concerned1 would be limited not by deficiency of mineral1 but of nitrogenous food4 ,hence also when farm-yard manure is liberally applied1 there is a gradual accumulation of valuable matters1 and a progressive improvement of the productive capacity of the soil4 ,it is far otherwise1 however1 if a special manure is employed1 because in that case the crop is thrown upon the resources of the soil itself for all its constituents except those contained in the substance employed1 and by persisting in its exclusive use exhaustion is the inevitable result4 ,it would be wrong1 however1 to infer from this1 that special manures are to be avoided4 ,on the contrary1 great benefits are derived from their judicious employment1 and the circumstances under which they are admissible may be readily gathered from what has already been said4 ,they are agents which bring into useful activity the dormant resources of the soil1 they restore the proper balance between its different constituents1 and supply the excessive demand of some particular elements4 ,thus1 for instance1 in a soil containing an abundant supply of mineral matters1 a salt of ammonia or nitric acid increases the crop1 by promoting the absorption of the substances already present4 ,so likewise a soil on which young cattle and milch cows have been long pastured has its fertility restored by phosphate of lime1 because that substance is removed in the bones and milk in relatively much larger proportion than any others4 ,the choice of a special manure is necessarily dependent on a great variety of circumstances1 and is governed partly by the nature of the soil1 and partly by that of the crop4 ,it is obvious that cases may occur in which any individual element of the plant may be deficient1 and ought to be supplied1 but experience has shown that1 as a rule1 nitrogen and phosphoric acid are the substances which it is most necessary to furnish in this way1 and which in all but exceptional cases produce a marked effect on the crop4 ,the other substances1 such as potash1 soda1 magnesia1 etc41 occasionally act beneficially1 but the results obtained from them are very uncertain1 and frequently entirely negative4 ,it has been commonly asserted that phosphates are specially adapted to root crops1 and ammonia or nitrates to the cereals1 and this statement is so far true1 that the former are used with advantage on the turnip1 while the latter act with great benefit on grain crops and more especially on oats and barley4 ,the effect of the latter1 however1 is more or less apparent in all crops and on all soils1 because it promotes the assimilation of the mineral matters already present4 ,but its peculiar importance lies in the power which it has of promoting the rapid development of the young plant1 causing it to send its roots out into the soil1 and to spread its leaves into the air1 thus enabling it to take from those two sources1 abundance of the useful substances existing in them4 ,but it ought to be distinctly understood1 that the statement that particular manures are specially suited to particular crops must be assumed with some reservation1 because everything depends upon the nature of the food contained in the soil4 ,it is well known that there are many soils in which ammonia acts more favourably on the turnip than phosphates1 and vice versa1 and the difference is often due to the previous treatment4 ,in many cases in which ammonia when first used proved most beneficial1 it now begins to lose its effect1 and the reason no doubt is1 that by its means the phosphates existing in these soils have been reduced in amount1 while the ammonia has accumulated1 so that a change in the system of manuring becomes necessary4 ,a general manure may be used year after year in a perfectly routine manner1 but where a special manure is employed1 the importance of watching its effects1 and altering it as circumstances indicate1 cannot be over-estimated4 ,the length of time during which special manures have been extensively used has not been sufficient to bring this prominently before the agriculturist1 but its importance must sooner or later force itself upon him1 and he will then see the necessity for studying the succession of manures as well as that of crops4 ,hitherto we have considered a manure merely as a source from which plants derive their food1 but it exercises a scarcely less important action on the chemical and physical properties of the soil4 ,farm-yard manure1 which1 as we shall afterwards see1 contains a large amount of decomposing vegetable and animal matters1 yields a supply of carbonic acid1 which operates on the mineral constituents1 promotes their further disintegration1 and thus liberates their useful elements4 ,it affects also their physical properties1 for it diminishes the tenacity of heavy clays2 each straw as it decomposes forming a channel through which the roots of plants1 air1 and moisture can penetrate more readily than through the stiff clay itself4 ,on the other hand1 it diminishes the porosity of light sandy soils1 causes them to retain moisture1 and generally makes their texture more suitable to the plant4 ,special manures probably act to some extent chemically on the soil1 but the nature of the changes they produce is as yet imperfectly understood4 ,superphosphates which are highly acid in all probability act powerfully on the mineral substances1 and common salt1 which1 though of little importance to the plant1 occasionally produces very striking effects1 appears to exercise some decomposing action on the soil4 ,it is difficult1 however1 to trace the mode in which they operate on a substance of such complexity as the soil4 ,lime1 as we shall afterwards see1 acts by promoting the decomposition of the vegetable matters on the soil1 and possibly some other substances may have a similar effect4 ,in the application of manures to the soil there are several circumstances which must be taken into consideration4 ,it is generally stated that they ought to be distributed as uniformly as possible1 but this is not always necessary nor even advisable1 and certainly is not acted on in practice4 ,much must depend upon the nature both of crop and soil4 ,when the former throws out long and widely penetrating roots1 the more uniformly the manure is distributed the better2 but if the rootlets are short1 it is clearly more advisable that it should be deposited at no great distance from the seed4 ,practically this is observed in the case of the potato and turnip1 which are short rooted1 and where the manure is generally deposited close to the seed4 ,but this course is never adopted with the long rooted cereals1 the manure being usually applied to the previous crop1 so that the repeated ploughings to which the soil is subjected in the interval may distribute what remains as widely and uniformly as possible4 ,in soils which are either excessively tenacious or light1 the accumulation of the manure close to the plants has also the effect of producing an artificial soil in their immediate neighbourhood1 containing abundance of plant-food1 and having physical properties better fitted for the support of the plant4 ,on the other hand1 when a special manure is used alone1 and with the view of promoting the assimilation of substances already existing in the soil1 the more uniform its distribution the better1 because it is essential that the roots which penetrate through it should find at every point they reach not only the original soil constituents1 but also the substances used to supplement their deficiencies4 ,,footnotes3 ,footnote ,k3 ,the quantities here taken are the averages deduced from the agricultural statistics taken in ,scotland some years since1 with the exception of hay and straw1 which are not included in them4 ,i have therefore assumed a reasonable quantity in these cases4 ,,chapter ,,viii4 ,,the ,,composition ,,and ,,properties ,,of ,,farm-,,yard ,,and ,,liquid ,,manures4 ,in the preceding chapter1 a general manure has been defined as one containing all the constituents of the crop to which it is to be applied1 in a state fitted for assimilation4 ,this condition is fulfilled only by substances derived from the vegetable and animal kingdoms1 and most effectually by a mixture of both4 ,on this account1 and also because its properties are such as enable it to act powerfully on the soil1 farm-yard manure must always be of the highest importance4 ,it is1 in fact1 the typical manure1 and in proportion as other substances approach it in properties and composition1 is their value for general purposes on the farm4 ,farm-yard manure is a mixture of the dung and urine of domestic animals1 with the straw used as litter2 and its value and composition must necessarily depend upon that of these substances1 as well as on the proportion in which they are mixed4 ,the dung of animals consists of that part of their food which passes through the intestinal canal without undergoing assimilation2 the urine containing the portion which has been assimilated and is again excreted1 in consequence of the changes which are proceeding in the tissues of the animal4 ,their composition is naturally very different1 and must be separately considered4 ,urine4--,urine consists of a variety of earthy and alkaline salts1 and of certain organic substances1 generally rich in nitrogen1 dissolved in a large quantity of water4 ,that of the different domestic animals has been frequently examined1 but the analyses of ,fromberg give the most complete view of their manurial value3-- ,horse4 ,swine4 ,ox4 ,goat4 ,sheep4 ,extractive matter #b4acb #j4adb #b4bdh #j4ajj #j4cdj soluble in water ,extractive matter #b4eej #j4chg #a4dba #j4ded #c4ccj soluble in spirit ,salts soluble in #b4cdj #j4iji #b4ddb #j4hej #a4ieg water ,salts insoluble in #a4hhj #j4jhh #j4aee #j4jhj #j4jeb water ,urea #a4bdd #j4bgc #a4igf #j4cgh #a4bfb ,hippuric acid #a4bfj 444 #j4eej #j4abe 444 ,mucus #j4jje #j4jje #j4jjg #j4jjf #j4jbe ,water #hh4ehi #ih4aif #ia4bja #ih4jjg #ib4hig ------ ------- ------- ------- ------- #ajj4jjj #ajj4jjj #ajj4jjj #ajj4jjj #ii4hfc ,composition of the ,ash of these ,urines4 ,horse4 ,swine4 ,ox4 ,goat4 ,sheep4 ,carbonate of lime #ab4ej 444 #a4jg trace #j4hb ,carbonate of magnesia #i4df 444 #f4ic #g4c #j4df ,carbonate of potash #df4ji #ab4aj #gg4bh trace 444 ,carbonate of soda #aj4cc 444 444 #ec4j #db4be ,sulphate of potash 444 444 #ac4cj 444 #b4ih ,sulphate of soda #ac4jd #g4jj 444 #be4j #g4gb ,phosphate of soda 444 #ai4jj 444 444 444 ,phosphate of lime ,phosphate of magnesia 444 #h4hj 444 444 #j4gj ,chloride of sodium #f4id #ec4aj #j4cj #ad4g #cb4ja ,chloride of potassium 444 trace 444 444 #ab4jj ,silica #j4ee 444 #j4ce 444 #a4jf ,oxide of iron and loss #a4ji 444 #j4gg 444 444 ------ ------ ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,human urine has been accurately examined by ,berzelius1 although his estimate of the proportion of urea is generally admitted to be above the average4 ,his analysis gives the following numbers3-- ,natural4 ,dry ,residue4 ,urea #c4jaj #dd4gj ,lactic acid1 lactate of ammonia1 #a4gad #be4eh and extractive matter ,uric acid #j4ajj #a4di ,mucus #j4jcb #j4dh ,sulphate of potash #j4cga #e4ed ,sulphate of soda #j4caf #d4gb ,phosphate of soda #j4bid #d4ci ,biphosphate of ammonia #j4afe #b4df ,chloride of sodium #j4dde #f4fd ,muriate of ammonia #j4aej #b4df ,phosphates of magnesia and lime #j4ajj #a4di ,silica #j4jjc #j4je ,water #ic4cjj ------- ------ #ajj4jjj #ajj4jj ,among the special organic constituents of the urine are three substances1 urea1 uric acid1 and hippuric acid1 which are of much importance in a manurial point of view4 ,the first of these is found in considerable quantity in the urine of all animals1 but is especially abundant in the carnivora4 ,uric acid is found only in these animals1 and is the most remarkable constituent of the excrement of birds1 serpents1 and many of the lower animals4 ,hippuric acid is most abundant in the herbivora4 ,these substances are all highly nitrogenous4 ,they contain-- ,urea4 ,uric ,acid4 ,hippuric ,acid4 ,carbon #bj4jj #cf4j #fj4g ,hydrogen #f4fj #b4d #e4j ,nitrogen #df4gj #cc4d #h4j ,oxygen #bf4gj #bh4b #bf4c ------ ----- ----- #ajj4jj #ajj4j #ajj4j ,they are extremely prone to change1 and in presence of animal matters readily ferment1 and are converted into salts of ammonia4 ,thus human urine1 which1 at the time of emission is free from smell of ammonia1 and has a slightly acid reaction1 becomes highly ammoniacal if it be kept for a few days4 ,this is due to the conversion of urea into carbonate of ammonia2 and the same change takes place1 though more slowly1 with uric and hippuric acids4 ,it is obvious1 from the foregoing analyses1 that great differences must exist in the manurial value of the urine of different animals4 ,not only do they vary greatly in the proportion of solid matters which they contain1 but also in the kind and quantity of their nitrogenous constituents4 ,they differ also in regard to their saline ingredients2 and while salts of potash and soda form the principal part of the ash of the urine of the ox1 sheep1 goat1 and horse1 and phosphoric acid and phosphates are entirely absent1 that of the pig contains a considerable quantity of the latter substances1 and in this respect more nearly resembles the urine of man4 ,human urine is also much richer in urea and nitrogenous constituents generally1 and has a higher value than any of the others4 ,it is especially worthy of notice that the urine of the purely herbivorous animals 7with the exception of the sheep1 which contains a small quantity71 are devoid of phosphates and urea2 and consequently1 when employed alone1 they are not general manures--a matter of some importance in relation to the subject of liquid manuring1 which will be afterwards discussed4 ,dung4--,the solid excrement of animals is equally variable in composition4 ,that of the domestic animals which had the ordinary winter food was found to have the following composition3-- ,horse4 ,cow4 ,sheep4 ,swine4 ,per-centage of water in the #gg4be #hb4de #ef4dg #gg4ac fresh excrement ,ash in the dry excrement #ac4cf #ae4bc #ac4di #cg4ag #ajj parts of ash contained-- ,horse4 ,cow4 ,sheep4 ,swine4 ,silica #fb4dj #fb4ed #ej4aa #ac4ai ,potash #aa4cj #b4ia #h4cb #c4fj ,soda #a4ih #j4ih #c4bh #c4dd ,chloride of sodium #j4jc #j4bc #j4ad #j4hi ,phosphate of iron #b4gc #h4ic #c4ih #aj4ee ,lime #d4fc #e4ga #ah4ae #b4fc ,magnesia #c4hd #aa4dg #e4de #b4bd ,phosphoric ,acid #h4ic #d4ge #g4eb #j4da ,sulphuric acid #a4hc #a4gg #b4fi #j4ij ,carbonic acid 444 trace trace #j4fj ,oxide of manganese #b4ac 444 444 444 ,sand 444 444 444 #fa4cg ---- ---- ---- ---- #ii4hj #ii4bi #ii4fd #ii4hb ,human faeces contain about #ge per cent of water2 and their dry residue was found by ,way to have the following composition3-- ,organic matter #hh4eb ,insoluble siliceous matters #a4dh ,oxide of iron #j4ed ,lime #a4gb ,magnesia #a4ee ,phosphoric acid #d4bg ,sulphuric acid #j4bd ,potash #a4ai ,soda #j4ca ,chloride of sodium #j4ah ------ #ajj4jj ,in a sample analyzed by myself there were found-- ,organic matter #hf4ge ,phosphates #h4ai ,alkaline salts1 containing #a4ah of phosphoric #b4ec acid ,insoluble matters #b4ec ------ #ajj4jj ,nitrogen #d4ei ,equal to ammonia #e4eg ,it is to be observed that the urine and dung of animals differ conspicuously in the composition of their ash1 the former being characterized by the abundance of alkaline salts1 while the latter contains these substances in small proportion1 but is rich in earthy matters1 and especially in phosphoric acid4 ,salts of potash1 for example1 form nine-tenths of the inorganic part of the urine of the ox1 while less than three per cent of that alkali is found in its dung4 ,phosphoric acid1 on the other hand1 is not met with in the urine1 but forms about ten per cent of the dung4 ,silica is the most abundant constituent of the dung1 but a large proportion of that found on analysis has been swallowed in the shape of grains of sand and particles of soil mechanically mixed with the food1 although part is also derived from the straw and grains1 which contain that substance in great abundance4 ,the difference in the quantity of nitrogen they contain is also very marked1 and is distinctly shown by the following analyses by ,boussingault1 which give the quantity of carbon1 hydrogen1 nitrogen1 oxygen1 and ash in the dung and urine of the horse and the cow in their natural state1 and after drying at #bab deg44 ---------------------------------------- --------------------- ,,horse4 ,,cow4 ---------------------------------------- ---------- ,natural4 ,dry4 ,natural4 ,dry4 ---------------------------------------- ---------- ,urine4 ,dung4,urine4,dung4,urine4 ,dung4,urine4,dung4 ---------------------------------------- ------ ,carbon #d4df #i4ef #cf4j #ch4g #c4ah #d4jb #bg4b #db4h ,hydrogen #j4dg #a4bf #c4h #e4a #j4cj #j4di #b4f #e4b ,nitrogen #a4ee #j4ed #ab4e #b4b #j4dd #j4bb #c4h #b4c ,oxygen #a4dj #i4ca #aa4c #cg4g #c4ji #c4ed #bf4d #cg4g ,ash #d4ea #d4jb #cf4d #af4c #d4fh #a4ac #dj4j #ab4j ,water #hg4fa #ge4ca #j4j #j4j #hh4ca #ij4fj #j4j #j4j ---------------------------------------- ------ #ajj4jjajj4jj #ajj4jajj4jajj4jjajj4jj #ajj4jajj4j ---------------------------------------- --------------- ,hence1 weight for weight1 the urine of the horse1 in its natural state1 contains three times as much nitrogen as its dung2 that of the cow twice as much2 and the difference1 especially in the horse1 is still more conspicuous when they are dry4 ,it is obvious that the quality of farm-yard manure must depend--#a4 ,on the kind of animal from which it is produced2 #b4 ,on the quantity of straw which has been used as litter2 #c4 ,on the nature of the food with which the animals have been supplied2 #d4 ,on the extent to which its valuable constituents have been rendered available by the treatment to which it has been subjected2 and #e4 ,on the care which has been taken to prevent the escape of the urine1 or of the ammonia produced by its decomposition4 ,the composition of farm-yard manure has engaged the attention of several chemists2 but there are still many points on which our information regarding it is less complete than might be desired4 ,its investigation is surrounded with peculiar difficulties1 not merely on account of its complexity1 but because its properties render it exceedingly difficult to obtain a sample which fairly represents its average composition4 ,in the case of long dung1 these difficulties are so great that it is scarcely possible to overcome them2 and hence1 discrepancies are occasionally to be met with in the analyses of the most careful experimenters4 ,the most minute and careful analyses yet made are those of ,voelcker1 who has compared the composition of fresh and rotten dung1 and studied the changes which the former undergoes when preserved in different ways4 ,he employed in his experiments both fresh and rotten dung1 and subjected them to different methods of treatment4 ,his analyses are given in the accompanying table1 in which column #a gives the composition of fresh long dung1 composed of cow and pig dung4 #b4 ,is dung of the same kind1 after having lain in a heap against a wall1 but otherwise unprotected from the weather for three months and eleven days in winter1 during which time little rain fell4 #c4 ,the same manure1 kept for the same time under a shed4 #d4 ,well rotten dung1 which had been kept in the manure heap upwards of six months4 #e4 ,the same1 after having lain against a wall for two months and nine days longer4 ---------------------------------------- ------------------------------- #a #b #c ---------------------------------------- ------------------------------- ,water #ff4ag #fi4hf #fg4cb ,soluble organic matters #b4dh #c4hf #b4fc ,soluble inorganic matters4 ,silica #j4bcg #j4bgi #j4bci ,phosphate of lime #j4bii #j4cjj #j4cca ,lime #j4jff #j4jdh #j4jef ,magnesia #j4jaa #j4jai #j4jjd ,potash #j4egc #a4jif #j4fgf ,soda #j4jea #j4ahg #j4aib ,chloride of sodium #j4jcj #j4ajf #j4jeh ,sulphuric acid #j4jee #j4afj #j4aai ,carbonic acid and loss #j4bah #j4gge #j4dde ----- #a4ed 444 #b4ig ----- #b4ab ,insoluble organic matters #be4gf #ah4dd #bj4df ,insoluble inorganic matters-- ,soluble silica #j4ifg #j4gab #a4hic ,insoluble silica #j4efa #j4heg #a4jge ,oxide of iron1 alumina1 and phosphates #j4eif #j4haj #a4ace ---------------------------------------- ------------------------------- ---------------------------------------- ----------------- #d #e ---------------------------------------- ----------------- ,water #ge4db #gc4ij ,soluble organic matters #c4ga #b4gj ,soluble inorganic matters ,silica #j4bed #j4adg ,phosphate of lime #j4chb #j4abi ,lime #j4aag #j4jah ,magnesia #j4jdg #j4jah ,potash #j4ddf #j4ifj ,soda #j4jbc #j4jhb ,chloride of sodium #j4jcg #j4jeb ,sulphuric acid #j4jeh #j4jgb ,carbonic acid and loss #j4ajf #j4ehd ----- #a4dg ----- #b4jf ,insoluble organic matters #ab4hb #ad4ci ,insoluble inorganic matters-- ,soluble silica #a4dbd #a4aj ,insoluble silica #a4jaj #a4ed ,oxide of iron1 alumina1 and phosphates #j4idg #j4cg ---------------------------------------- ----------------- ---------------------------------------- ------------------------------- #a #b #c ---------------------------------------- ------------------------------- ,containing phosphoric acid 7#j4agh7 7#j4agg7 7#j4bih7 ,equal to bone earth 7#j4chf7 7#j4bgg7 7#j4fdf7 ,lime #a4abj #a4bia #a4hfh ,magnesia #j4adc #a4jbi #j4jgh ,potash #j4jii #j4abg #j4bjh ,soda #j4jai #j4jdf #j4jch ,sulphuric acid #j4jfa #j4jii #j4jih ,carbonic acid and loss #j4dhd #j4ibi #a4jgg ----- #d4je ----- #d4ij ----- #g4dg ----- ----- ------ #ajj4jj #ajj4jj #ajj4jj ,containing nitrogen #j4adi #j4bgj #j4agj ,equal to ammonia #j4aha #j4cbj #j4bjf ,containing nitrogen #j4did #j4dgj #j4ehj ,equal to ammonia #j4eii #j4egj #j4gjj ,total nitrogen #j4fdc #j4gdj #j4gej ,equal to ammonia #j4ghj #j4hij #j4ijf ---------------------------------------- ------------------------------- ---------------------------------------- ----------------- #d #e ---------------------------------------- ----------------- ,containing phosphoric acid 7#j4bgd7 7#j4jf7 ,equal to bone earth 7#j4egc7 7#j4aj7 ,lime #a4ffg #b4be ,magnesia #j4jia #j4jb ,potash #j4jde #j4ab ,soda #j4jch #j4ja ,sulphuric acid #j4jfc #j4aj ,carbonic acid and loss #a4bie #a4dd ----- #f4eh ---- #f4ie ----- ------ #ajj4jj #ajj4jj ,containing nitrogen #j4big #j4adi ,equal to ammonia #j4cfj #j4ahj ,containing nitrogen #j4cji #j4fac ,equal to ammonia #j4cge #j4gdd ,total nitrogen #j4fjf #j4gfb ,equal to ammonia #j4gce #j4ibd ---------------------------------------- ----------------- ,on examining and comparing these analyses1 it appears that the differences are by no means great1 although1 on the whole1 they tend to show that1 weight for weight1 well-rotten dung is superior to fresh1 provided it has been properly treated4 ,not only is the quantity of valuable matters existing in the soluble state materially increased1 whereby the dung is enabled to act with greater rapidity1 but1 owing to evaporation and the escape of carbonic acid1 produced by the decomposition of the organic substances1 the proportion of those constituents which are most important to the plant is increased4 ,this is particularly to be noticed1 in regard to the nitrogen1 which has distinctly increased in all cases in which the dung has been kept for some time2 and the practical importance of this observation is very great1 because it has been commonly supposed that1 during the process of fermentation1 ammonia is liable to escape into the air4 ,it would appear1 however1 that there is but little risk of loss in this way1 so long as the dung-heap is left undisturbed2 and it is only when it is turned that any appreciable quantity of ammonia volatilizes4 ,it is different1 however1 with the action of rain1 which soon removes1 by solution1 a considerable quantity of the nitrogen contained in farm-yard manure2 and the deterioration must necessarily be most conspicuous in rotten dung1 which sometimes contains nearly half of its nitrogen in a soluble condition4 ,the effect produced in this way is conspicuously seen1 by the results of weighings and analyses of small experimental dung-heaps1 made by ,dr4 ,voelcker at different periods4 ,the subjoined table shows the composition of the heap1 lying against a wall1 and exposed to the weather at different periods3-- ---------------------------------------- ----------------------------- ,,when ,,put ,,up4 ---------------------------------------- ,nov #c;d ,april #cjth ,aug #bc;d ,nov #aeth #ahed4 #ahee4 #ahee4 #ahee4 ---------------------------------------- ,weight of manure in lbs4 #bhch #bjbf #aiid #aigd ---------------------------------------- ,water #ahgg4i #accf4a #aeje4c #adff4e ,dry ,matter #ifj4a #fhi4i #dhh4g #ejg4e ---------------------------------------- ,consisting of-- ,soluble organic matter #gj4ch #hf4ea #eh4hc #ed4jd mineral matter #dc4ga #eg4hh #ci4af #cf4hi ,insoluble organic matter #gca4jg #chi4gd #bdc4bb #bad4ib mineral matter #aad4id #aee4gg #adg4di #bja4jg ---------------------------------------- ,total nitrogen #ah4bc #ah4ad #ac4ad #ac4jc ,equal to ammonia #bb4ad #bb4jb #ae4if #ae4ge ---------------------------------------- -------------------------- ,in this case1 during the winter six months1 which were very dry1 the manure lost #eda4h lbs4 of water and #bgj4b lbs4 of dry matter1 but the nitrogen remained completely unchanged4 ,but during the succeeding semi-annual period1 when rain fell abundantly1 the quantity of nitrogen is diminished by nearly a third1 while the water has increased1 and the loss of dry matter by fermentation1 notwithstanding the high temperature of the summer months1 was only #ahb4d lbs4 ,the soluble mineral matters also1 which increased during the first period1 are again reduced during the second1 until they also fall to about two-thirds of their maximum quantity4 ,that this effect is to be attributed to the solvent action of rain is sufficiently obvious1 from a comparison of the results afforded by the other heaps1 which had been kept under cover during the same period1 as shown below4 ---------------------------------------- -------------------------------- ,,when ,,put ,,up4 ---------------------------------------- --- ,nov4 #c;d1 ,april #cjth ,aug4 #bc;d ,nov4 #aeth #ahed4 #ahee4 #ahee4 #ahee4 ---------------------------------------- --- ,weight of manure in lbs4 #cbeh #afac #abig #abce ---------------------------------------- --- ,water #baef4j #iag4f #efc4b #ead4e ,dry ,matter #aajb4j #fie4d #gcc4h #gbj4e ---------------------------------------- --- ,consisting of-- ,soluble organic matter #hj4gg #gd4fh #ec4ef #ff4bh mineral matter #ej4ad #ed4ea #ci4ee #ed4fh ,insoluble organic matter #hci4ag #daj4bd #ccg4cb #cda4ig mineral matter #aca4ib #aee4ig #cjc4cg #beg4eg ---------------------------------------- --- ,total nitrogen #bj4ic #ai4bf #af4ed #a4gi ,equal to ammonia #be4dj #bc4cc #bj4jh #b4ha ---------------------------------------- ----------------------------- ,the loss of nitrogen is here comparatively trifling1 and during the whole year1 but little exceeds two pounds1 of which the greater part escapes during the first six months1 and the soluble inorganic matters are almost unchanged4 ,the total weight of the manure1 however1 undergoes a very great reduction1 due chiefly to evaporation of water1 but in part also to the loss of organic matters evolved in the form of carbonic acid during fermentation4 ,when the manure is spread out1 as it is usually found under cattle in open yards1 the deterioration is very great1 a quantity thus treated having lost1 in the course of a year1 nearly two-thirds of its nitrogen1 and four-fifths of its soluble inorganic matters4 ,the general conclusion deducible from these analyses is that1 provided it be carefully prepared1 farm-yard manure does not differ very largely in value1 although the balance is in favour of the well-rotten dung4 ,this result is in accordance with that obtained by other experimenters1 who have generally found from #j4e to #j4f per cent of nitrogen1 and #a or #b per cent of phosphates4 ,but when carelessly managed1 it may fall greatly short of this standard1 as is particularly seen in a sample examined by ,cameron1 which had been so effectually washed out by the rain1 as to retain only #j4ae per cent of ammonia4 ,these cases1 however1 are exceptional1 and well made and well preserved farm-yard manure will generally be found to differ comparatively little in value2 and when bought at the ordinary price1 the purchaser1 as we shall afterwards more particularly see1 is pretty sure to get full value for his money1 and the specialities of its management are of comparatively little moment to him4 ,but the case is very different when the person who uses the manure has also to manufacture it4 ,the experiments already quoted have shown that1 though the manure made in the ordinary manner may1 weight for weight1 be as valuable as at first1 the loss during the period of its preservation is usually very large1 and it becomes extremely important to determine the mode in which it may be reduced to the minimum4 ,in the production of farm-yard manure of the highest quality1 the object to be held in view is to retain1 as effectually as possible1 all the valuable constituents of the dung and urine4 ,but in considering the question here1 it will be sufficient to refer exclusively to its nitrogen1 both because it is the most important1 and also because the circumstances which favour its preservation are most advantageous to the other constituents4 ,in the management of the dung-heap1 there are three things to be kept in view3--,first1 ,to obtain a manure containing the largest possible amount of nitrogen2 secondly1 ,to convert that nitrogen more or less completely into ammonia2 and thirdly1 ,to retain it effectually4 ,as far as the first of these points is concerned1 it must be obvious that much will depend on the nature and quantity of the food with which the animals yielding the dung are supplied1 and the period of the fattening process at which it is collected4 ,when lean beasts are put up to feed1 they at first exhaust the food much more completely than they do when they are nearly fattened1 and the manure produced is very inferior at first1 and goes on gradually improving in quality as the animal becomes fat4 ,when the food is rich in nitrogenous compounds1 the value of the manure is considerably increased4 ,it has been ascertained1 for instance1 that when oil-cake has been used1 not less than seven-eighths of the valuable matters contained in it reappear in the excrements2 and as that substance is highly nitrogenous1 the dung ought1 weight for weight1 to contain a larger amount of that element4 ,that it actually does so1 ,i satisfied myself by experiments1 made some years since1 when the dung and urine of animals fed on turnips1 with and without oil-cake1 were examined2 but unfortunately1 no determination of the total quantity of the excretions could be made1 so that it was impossible to estimate the increased value4 ,it has been commonly supposed that when cattle are fed with oil-cake1 the increased value of the manure is equal to from one-half to two-thirds the price of the oil-cake2 but this is a rather exaggerated estimate as regards linseed-cake1 although it falls short of the truth in the case of rape1 as we shall afterwards more particularly see4 ,although it may be possible1 in this way1 to increase the quantity of nitrogen as a manure1 there is a limit to its accumulation1 due to the fact1 that it is contained most abundantly in the urine1 which can only be retained by the use of a sufficient supply of litter4 ,where that is deficient1 the dung-heap becomes too moist1 and the fluid and most valuable part drains off1 either to be lost1 or to be collected in the liquid manure-tank4 ,in the well managed manure-heap1 the quantity of litter should be sufficient to retain the greater part of the liquid manure1 and to admit of only a small quantity draining from it1 which should be pumped up at intervals1 so as to keep the whole in a proper state of moisture4 ,attention to this point is of great moment1 and materially affects the fermentation4 ,when it is too moist or too dry1 that process is equally checked2 in the former case by the exclusion of air1 which is essential to it2 and in the latter1 by the want of water1 without which the air cannot act4 ,the exact mode in which the manure is to be managed must greatly depend on whether the supply of litter is large or small4 ,in the latter case the urine escapes1 and is collected in the liquid manure-tank1 and must be used by irrigation1 and in some cases this mode of application has advantages1 but in general1 it is preferable to avoid it1 and have recourse to substances which increase the bulk of the heap sufficiently to make it retain the whole of the liquid4 ,for this purpose1 clay1 or still better1 the vegetable refuse of the farm1 such as weeds1 ditch cleanings1 leaves1 and1 in short1 any porous matters1 may be used4 ,but by far the best substance1 when it can be obtained1 is dry peat1 which not only absorbs the fluid1 but fixes the ammonia1 by converting it more or less completely into humate4 ,reference has been already made to the absorbent power of peat in the section on soils1 but it may be mentioned here that accurate experiment has shown that a good peat will absorb about #b per cent,l of ammonia1 and when dry will still retain from #a to #a4e per cent1 or nearly twice as much as would be yielded by the whole nitrogen of an equal weight of farm-yard manure4 ,peat charcoal has been recommended for the same purpose1 but careful experiment has shown that it does not absorb ammonia1 although it removes putrid odour2 and though it may be usefully employed when it is wished to deodorize the manure heap1 it must not be trusted to for fixing the ammonia4 ,much stress has frequently been laid on the advantage to be derived from the use of substances capable of combining chemically with the ammonia produced during the fermentation of dung and gypsum1 sulphate of iron1 chloride of manganese1 sulphate of magnesia1 and sulphuric acid1 have been proposed for this purpose1 and have been used occasionally1 though not extensively4 ,they all answer the purpose of fixing the ammonia1 that is1 of preventing its escaping into the air2 but the risk of loss in this way appears to have been much exaggerated1 for a delicate test-paper1 held over a manure-heap1 is not affected2 and during fermentation1 humic acid is produced in such abundance1 as to combine with the greater part of the ammonia4 ,the real source of deterioration is the escape of the soluble matters in the drainings from the manure-heap1 which is not prevented by any of these substances2 and where no means are taken to preserve or retain this portion1 the loss is extremely large1 and amounts1 under ordinary circumstances1 to from a third to a half of the whole value of the manure4 ,manure1 therefore1 cannot be exposed to the weather without losing a proportion of its valuable matters1 depending upon the quantity of rain which falls upon it4 ,hence it is obvious that great advantage must be derived1 especially in rainy districts1 from covered manure-pits4 ,this plan has been introduced on some farms with good effect2 but the expense and doubts as to the benefits derived from it1 have hitherto prevented the practice becoming general4 ,the principal difficulty experienced in the use of the covered dung-pit is1 that1 where the litter is abundant1 the urine does not supply a sufficiency of moisture to promote the active fermentation of the dung1 and it becomes necessary to pump water over it at intervals2 but when this is properly done1 the quality of the manure is excellent1 and its valuable matters are most thoroughly economized4 ,although covered dung-pits have been but little used1 their benefits have been indirectly obtained by the method of box-feeding1 one of the great advantages of which is held to be the production of a manure of superior quality to that obtained in the old way4 ,in box-feeding none of the dung or urine is removed from under the animals1 but is trampled down by their feet1 and new quantities of litter being constantly added1 the whole is consolidated into a compact mass1 by which the urine is entirely retained4 ,whatever objection may be taken to this system1 so far as the health of the animals is concerned1 there is no doubt as to the complete economy of the manure1 provided the quantity of litter used be sufficient to retain the whole of the liquid4 ,but its advantage is entirely dependent on the possibility of fulfilling this condition4 ,whether box manure is really superior to that which can be prepared by the ordinary method is very questionable1 but it undoubtedly surpasses a large proportion of that actually produced4 ,it is more than probable1 however1 that the careful management of the manure-heap would yield an equally good product4 ,it is manifest that the same number of cattle1 fed in the same way1 on the same food1 and supplied with the same quantity of litter1 must always excrete the same quantities of valuable matters2 and the only question to be solved is1 whether they are more effectually preserved in the one way than the other8 ,it will be readily seen that this cannot be done by analysis alone1 but that it is necessary to conjoin with it a determination of the total weight of manure produced2 for though1 weight for weight1 box manure may be better than ordinary farm-yard manure1 the total quantity obtained by the latter method1 from a given number of cattle1 may be so much greater1 that the deficiency in quality may be compensated for4 ,at the present time our knowledge is too limited to admit of a definite opinion on this subject1 but it is highly deserving of the combined investigation of the farmer and the chemist4 ,supposing the conditions which produce the manure containing the largest quantity of nitrogen to have been fulfilled1 we have now to consider those which affect its evolution in the form of ammonia4 ,this change is effected by fermentation4 ,when a quantity of manure is left to itself it becomes hot1 and gradually diminishes in bulk1 and if it be turned over after some time1 the smell of ammonia may be more or less distinctly observed4 ,this ammonia is produced1 in the first instance1 from the urine1 the nitrogenous constituents of which are rapidly decomposed1 and the fermentation thus set up in the mass of manure extends first to the solid dung1 and then to the straw of the litter1 and gradually proceeds until a large quantity of ammonia is produced4 ,when fresh manure is deposited in the soil1 the same changes occur1 but they then proceed more slowly1 and experience has shown that a much smaller effect is produced on the crop to which it has been applied than when it has been well fermented in the heap4 ,this effect is consistent with theory1 which would further indicate that well-fermented dung must be especially advantageous when applied to quick-growing crops1 and less necessary to those which come slowly to maturity4 ,as a rule1 well fermented manure is to be preferred1 provided it has been well managed and carefully prepared2 but when this has not been done1 and the manure has been exposed to the weather1 or made in open courts or hammels1 the economic advantages are all on the side of the fresh dung4 ,it may be questioned also whether1 now that there are so many other available sources of ammonia1 it may not in many instances be advantageous to use the dung fresh1 conjoined with a sufficient quantity of some salt of ammonia1 or other substance fitted to supply the quantity of that element necessary for the requirements of the crop4 ,after the farm-yard manure has been prepared at the homestead1 it is often necessary to cart it out to the field some time before it is to be applied1 and it is a question of some importance to determine how it may be best preserved there4 ,the general practice is to store it in heaps in the corners of the fields1 but some difference of opinion exists as to whether it should be lightly thrown up so as to leave it in a porous state1 and so promote its further fermentation1 or whether it should be consolidated as much as possible by driving the carts on to the top of the heap during its construction4 ,considering the risks to which the manure is exposed on the field1 the latter plan would appear to be the best4 ,it is advisable also to interstratify the dung with dry soil1 so as to absorb any liquid which may tend to escape from it1 and it should also be covered with a well-beaten layer of earth1 in order to exclude the rain4 ,although these precautions must not be omitted if the manure is to be stored in heaps1 it will probably be often found quite as advantageous to spread it at once1 and leave it lying on the surface until it is convenient to plough it4 ,the loss of ammonia by volatilization will1 under such circumstances1 especially in the cold season of the year1 be very trifling1 and the rain which falls will only serve to incorporate the soluble matters with the soil1 where they will be retained by its absorptive power4 ,in the actual application of the manure to the crop1 several points require consideration4 ,it is especially important to determine whether it ought to be uniformly distributed through the soil1 or be kept near the roots of the plants4 ,both systems have their advocates1 and each has advantages in particular cases4 ,the choice between the two must greatly depend upon the nature of the crop and the soil4 ,when the former is of a kind which spreads its roots wide and deep through the soil1 the more uniformly the manure can be distributed the better2 but when it is used with plants whose roots do not travel far1 it is more advantageous to accumulate it near the seeds4 ,obvious advantages also attend this practice in soils which are either too heavy or too light4 ,when1 for example1 it is necessary to cultivate turnips in a heavy clay1 the manure put into the drills produces a kind of artificial soil in the neighbourhood of the plants1 in which the bulbs expand more readily than in the clay itself4 ,on the other hand1 when a large quantity of dung1 in a state of active fermentation1 comes into immediate contact with the roots1 its effect is not unfrequently injurious4 ,these and many other points1 which will readily suggest themselves to any one who studies the composition and properties of farm-yard manure1 belong more strictly to the subject of practical agriculture1 and need not be enlarged on here4 ,in the present state of agriculture1 a proper estimate of the money value of farm-yard manure is of much importance in an economic point of view1 and many matters connected with the profitable management of a farm must hinge upon it4 ,if an estimate be made upon the principle which will be explained when we come to treat of artificial manures1 it appears that fresh farm-yard manure of good quality is worth from #abs4 to #aes4 per ton1 and well-rotted dung rather more4 ,it is questionable1 however1 whether the system of valuation which is accurate in the case of a guano or other rapidly acting substance1 is applicable to farm-yard manure1 the effects of which extend over some years4 ,a deduction must be made for the years during which the manure remains unproductive1 and also for the additional expense incurred in carting and distributing a substance so much more bulky than the so-called portable manures1 and it would not be safe to estimate its value at more than #gs4 or #hs4 per ton4 ,liquid ,manure4--,this term is applied to the urine of the animals fed on the farm1 and to the drainings from the manure-heap1 which1 in place of being returned to it1 are allowed to flow away1 and collected in tanks1 from which they are distributed by a watering-cart1 or according to the method recently introduced in ,ayrshire1 and since adopted in other places1 by pipes laid under-ground in the fields1 and through which the manure is either pumped by steam-power1 or1 where the necessary inclination can be obtained1 is distributed by gravitation4 ,that liquid manure must necessarily be valuable1 is an inference which maybe at once drawn from the analyses of the urine of different animals already given1 and of which it chiefly consists4 ,in addition to the urine1 however1 it contains also the soluble organic and mineral matters of the dung1 as well as a quantity of solid matters in suspension1 among which phosphates are found1 and thus it possesses a supply of an element which would be almost entirely deficient if it were composed of urine alone4 ,in the following analyses by ,professor ,johnston1 ,no4 #a is the drainings of the manure-heap when exposed to rain2 and ,no4 #b the same1 when moistened with cows' urine pumped over it1 the results being expressed in grains per gallon3-- ,no4 #a4 ,no4 #b4 ,ammonia #i4f #ba4e ,organic matter #bjj4h #gg4f ,ash #bfh4h #eah4d ----- ----- ,total solids in a gallon #dgi4b #fag4e ,the ash contained-- ,alkaline salts #bjg4h #dbj4d ,phosphates #be4a #dd4e ,carbonate of lime #ah4b #ca4a ,carbonate of magnesia1 and loss #d4c #c4d ,silica and alumina #ac4d #ai4j ----- ----- #bfh4h #eah4d ,more elaborate analyses of the same fluid have since been made by ,dr4 ,voelcker1 with the subjoined results per gallon3-- #a4 #b4 #c4 ,organic matters and ammoniacal #bfc4hj #bej4fc #gj4aba salts ,silica #b4di #i4ih #a4aed ,oxide of iron #j4gj #j4fh 444 ,lime #e4cd #be4ah #ac4jaa ,magnesia #b4if #ae4cc #a4ffj ,potash #ajc4bc #aab4bf #ac4daa ,chloride of potassium #gb4jj #gg4ch #g4gab ,chloride of sodium #ag4ah #df4jc #ag4beh ,phosphoric acid #b4gj #i4ea #b4cjd ,sulphuric acid #bb4ca #cg4fj #c4djh ,carbonic acid1 and loss #cc4ij #bg4ie #ad4jbe ------ ------ ------- ,total solids #ebf4fa #fab4ec #add4jfd ,ammonia #aad4af #bb4ca #bf4fdg ,the differences are here very remarkable1 especially in the quantity of ammonia1 which is exceedingly large in the first sample4 ,all of them are particularly rich in potash1 and contain but a small proportion of phosphoric acid4 ,the general inference to be deduced from them is1 that liquid manure is a most important source of the alkalis and ammonia1 and must be peculiarly valuable on soils in which these substances are deficient4 ,the system of liquid manuring1 originally introduced by ,mr4 ,kennedy of ,myremill1 ,ayrshire1 and which has since been adopted in some other places1 differs from liquid manuring in its strict sense1 for not only are the drainings of the manure-heap employed1 but the whole solid excrements are mixed with water in a tank1 and rape-dust and other substances occasionally added1 and distributed through the pipes4 ,it has been abandoned on ,mr4 ,kennedy's farm1 but is in use at ,tiptree ,hall1 and on the farm of ,mr4 ,ralston1 ,lagg1 where the fluid is distributed by gravitation4 ,the arrangements employed by ,mr4 ,mechi are identical with those formerly in use at ,myremill4 ,the greater part of the stock is kept on boards1 and the liquid and solid excrements are collected together in the tank1 and largely diluted before distribution4 ,the liquid from the tanks has been recently examined by ,dr4 ,voelcker1 who found it to contain per gallon-- ,organic matter and ammoniacal salts #ec4jc ,soluble silica #f4dg ,insoluble siliceous matter 7clay7 #ae4ag ,oxide of iron and alumina #b4cf ,lime #f4fj ,magnesia #a4gc ----- ,potash #j4ce ,chloride of potassium #a4ie ,chloride of sodium #d4ha ,phosphoric acid #c4gb ,sulphuric acid #a4id ,carbonic acid1 and loss #j4dg ----- ,total solids #if4fj ,ammonia #h4aj ,the quantity of this liquid distributed per acre is about #ej1jjj gallons1 at a cost of #b;d4 per gallon4 ,as this quantity contains about #ci lbs4 of ammonia1 it must be nearly equivalent to #b cwt4 of ,peruvian guano1 which costs1 with the expense of spreading1 from #bhs4 to #cjs4 per acre1 while the cost of distributing the liquid exceeds ,l#a3 #ags4 per acre4 ,on the other hand1 the rapidity with which liquid manure produces its effect must be taken into account4 ,it is on this that its chief value depends1 and especially when applied to grass land in early spring1 it produces an abundant crop just when turnips and other winter food are exhausted4 ,mr4 ,telfer1 ,cunning ,park1 who has used this system for a good many years1 has come to the conclusion that it is only in this way that it can be made profitable2 and though pipes are laid all over his farm1 he has latterly restricted the use of the liquid manure entirely to ,italian ryegrass4 ,its effect on the cereals is much less marked1 and it can scarcely be considered as capable of advantageous application to the general operations of the farm4 ,neither can liquid manure be applied to all soils4 ,it fails entirely on heavy clays1 but is peculiarly adapted to light sandy soils2 and even barren sand may by its repeated application1 be made to yield luxuriant crops4 ,it is not likely that the system of liquid manuring will extend1 except in localities where it is possible to distribute it by gravitation2 and even then1 it will probably be found most economical to restrict its use to one portion of the farm2 and for that purpose1 the poorest and most sandy soil ought to be selected4 ,sewage ,manure4--,the use of the sewage of towns as a manure is closely connected with that of the liquid manure produced on the farm4 ,its application must take place in a similar manner1 and be governed by the same principles4 ,although numerous attempts have been made to convert it into a solid form1 or to precipitate its valuable matter1 none of them have succeeded2 nor can it be expected that any plan can be devised for the purpose1 because the most important manurial constituents are chiefly soluble1 and cannot be converted into an insoluble state1 or precipitated from their solution4 ,in its liquid form1 however1 sewage manure has been employed with the best possible effect in the cultivation of meadows4 ,the most important instance of its application is in the neighbourhood of ,edinburgh1 where #cbe acres receive the sewage of nearly half the town1 and have been converted from barren sand into land which yields from ,l#bj to ,l#cj per acre4 ,the contents of the sewer1 taken just before it flows into the first irrigated meadow1 near ,lochend1 were found to contain per gallon-- ,soluble organic matter #ba4ij ,insoluble organic matter #ba4gj ,peroxide of iron and alumina #b4ja ,lime #aj4ej ,magnesia #b4jj ,sulphuric acid #f4ji ,phosphoric acid #f4ad ----- ,chlorine #ab4bj ,potash #b4hi ,soda #ac4bg ,silica #f4ej ------ #aje4bj ,ammonia #ad4ij ,it is interesting to notice that this sewage is superior in every respect to the liquid manure used at ,tiptree ,hall2 and the good effects obtained from its application1 in the large quantities in which it is used in the ,craigentinny meadows1 may be well imagined4 ,it operates1 not merely by the substances which it holds in solution1 but also by depositing a large quantity of matters carried along in suspension1 and is in reality warping with a substance greatly superior to river-mud4 ,a deposit collected in a tank1 where the sewage passes through a farm1 is used as a manure1 and contains-- ,peroxide of iron and alumina #d4de ,lime #a4gd ,magnesia #j4ci ,potash #j4aj ,soda #j4jf ,phosphoric acid #a4jh ,sulphuric acid #j4af ,organic matter #ag4ie ,sand #bj4ea ,water #ec4ef ------ #ajj4jj ,ammonia #j4ic ,and even1 though containing more than half its weight of water and #bj per cent of sand1 this substance has considerable value as a manure4 ,the growing evils of the existing system of sewage1 and the enormous waste of a manurial matter1 which the experience of the ,craigentinny meadows has shewn to be productive of the most important effects1 has recently directed much attention to the conversion of the contents of our sewers into a useful manure4 ,numerous plans for its precipitation and conversion into a solid manure have been proposed1 but most of these have shewn an entire ignorance of the fundamental principles of chemistry1 and the best only succeed in precipitating a very small proportion of its valuable matters1 and leave almost the whole of the ammonia1 as well as the greater part of the fixed alkalies1 in solution4 ,nor is it to be expected that any process will be discovered by which these substances can be precipitated1 because solubility is the special characteristic of their compounds1 and no means is known by which it is possible to convert them into an insoluble form4 ,if sewage is to be used at all1 there seems little doubt that it must be by applying it entire1 and in the liquid state4 ,but here again1 the expense of conveying it on to the land becomes an obstacle which it must frequently be impossible to overcome4 ,when it can be conveyed by gravitation1 as is the case in the neighbourhood of ,edinburgh1 it may undoubtedly be used with the utmost advantage1 and with the very best economic results4 ,but when it requires to be carried to a great distance through pipes1 and raised to a high level by pumping1 all these advantages disappear4 ,if the cost of application amounts to #b;d4 a gallon1 as in ,mr4 ,mechi's case1 or even to half that sum1 it may be fairly concluded that it cannot be used with any great prospect of large economic results1 and that1 unless under very exceptional cases1 it must be unprofitable4 ,the chances of success must also greatly depend upon the kind of soil on which it is used4 ,experience has shewn that its effects are most beneficial on light and deep sandy soils1 but that on heavy retentive clays it is without effect1 or even absolutely injurious4 ,in clay soils it is important to use every means of getting rid of moisture1 and any plan which adds #bjj or #cjj tons of water to them1 only aggravates their natural defects to an extent which more than counterbalances the benefits derived from the manurial matter it contains4 ,whatever the ultimate result of the use of town sewage in the liquid form may be1 it is unlikely that it will be employed in general agricultural practice4 ,it is more probable that it will be found necessary to set apart a certain breadth of land to be treated by it exclusively4 ,many plans have been proposed for conveying it through considerable districts1 and selling to the surrounding farmers the quantities which they require1 but wherever large sewage-works are established1 it will be impossible to depend on a precarious demand1 and the promoters of such schemes will be compelled1 as part of their speculation1 to supply not only the manure1 but the land on which it is to be used4 ,indeed1 the difficulties attending the whole question are so formidable1 that even those who are most anxious to see a stop put to the waste of manurial matter must admit that the prospect of a successful economic result is not encouraging4 ,nor is it likely that anything will be done until the whole system of managing town refuse is changed1 and in place of deluging it with water1 some plan can be contrived which1 while fulfilling sanatory requirements1 shall preserve it in a concentrated form1 or convert it into a dry and inodorous substance4 ,,footnotes3 ,footnote ,l3 ,report on the economic uses of peat4 ,highland ,society's ,transactions1 ,n4,s41 vol4 iv4 p4 #edi4 ,,chapter ,,ix4 ,,composition ,,and ,,properties ,,of ,,vegetable ,,manures4 ,many vegetable substances have been employed as manures1 either alone or as auxiliaries to farm-yard manure4 ,like that substance1 they are general manures1 and contain all the constituents of ordinary crops2 but1 owing to the absence of animal matter1 they in general undergo decomposition and fermentation much more slowly1 although some of them contain a so largely preponderating proportion of nitrogen1 that they may in some respects be compared to the strictly nitrogenous manures4 ,rape-dust1 ,mustard1 ,cotton and ,castor ,cake4--,rape-dust has long been employed as a manure1 and the success which has attended its use has led to the introduction of the refuse cake from some other oil seeds1 such as those of mustard and castor-oil1 which cannot be employed for feeding4 ,like the seeds of all plants1 these substances are rich in nitrogen1 and their ash1 containing of course all the constituents of the plant1 supplies the necessary inorganic elements4 ,the following are analyses of these substances1 which1 in addition to the amount of nitrogen and phosphates1 shew also that of water and oil1 to which reference will be made in a future chapter1 in relation to the feeding value of some of them4 ,the detailed composition of their ash may be judged of from that of the seeds from which they are made1 and which have been given under that head4 ---------------------------------------- --------------------------- ,rape-,cake4 ,poppy-,cake4 ,cotton-seed ,castor- ,cake4 ,cake4 ---------------------------------------- ------- ,water #aj4fh #aa4fc #aa4ai #ab4ca ,oil #aa4aj #e4ie #i4jh #bd4cb ,albuminious #bi4ec #ca4af #be4af #ba4ia compounds ,ash #g4gi #ab4ih #e4fd #f4jh ,other constituents #dj4ij #ch4ah #dh4ic #ce4ch ---------------------------------------- ------- #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,nitrogen #d4ch #d4id #c4ie #c4bj ,silica #a4ah #c4cf #a4cb #a4if ,phosphates #c4hg #fi4c #b4ai #b4ha ,phosphoric acid in combination #j4ci #c4bg #j4ae #j4fd with alkalies ---------------------------------------- --------------------------- ,a general similarity may be observed in the composition of all these substances2 they are rich in nitrogen1 and contain as much of that element as is found in six or seven times their weight of farm-yard manure1 and a somewhat similar proportion exists in the amount of phosphates1 and probably of their other constituents4 ,they have all been employed with success1 but the most accurate observations have been made with rape-dust1 which has been longer and more extensively used than any of the others4 ,it has been employed alone for turnips1 or mixed with farm-yard manure1 and also as a top-dressing to cereals4 ,but the most marked advantage is derived from it when applied in the latter way on land which has been much exhausted1 and its effects are then very striking4 ,an adequate supply of moisture is essential to the production of its full effects1 and hence it often proves a failure in very dry seasons1 and on dry soils4 ,it must not be applied in too great abundance1 experience having shewn that after a certain point has been reached1 an increase in the quantity produces no benefit1 and even sometimes positively diminishes the crop4 ,the other substances of the same class1 in all probability1 act in the same way1 but as their introduction is recent1 and their use limited1 less is known regarding their effects4 ,malt-,dust1 ,bran1 ,chaff1 etc4--,the value of these substances as manures is chiefly dependent on the nitrogen they contain1 though to some extent also on their inorganic constituents4 ,malt-dust contains about #d4e per cent1 and bran #c4b per cent of nitrogen4 ,but they are little used as manures1 as they can generally be more advantageously employed for feeding4 ,the value of chaff more nearly resembles that of straw4 ,straw is occasionally employed as a manure1 and sometimes even as a top-dressing for grass land4 ,it is generally admitted1 however1 that its application in the dry state1 and especially as a top-dressing1 is a practice not to be recommended1 as it decomposes too slowly in the soil2 and it is always desirable to ferment it in the manure heap1 so as to facilitate the production of ammonia from its nitrogen4 ,still circumstances may occur in which it becomes necessary to employ it in the dry state1 and it will generally prove most valuable on heavy soils1 which it serves to keep open1 and so promotes the access of air1 and enables it to act on the soil4 ,on light sandy soils it generally proves less advantageous1 as its tendency of course is to increase the openness of the soil1 and render it less able to retain the essential constituents of the plant4 ,the quantity of nitrogen in straw does not exceed #j4b per cent1 and its value is mainly due to its inorganic constituents and to its mechanical effect on the soil4 ,saw-dust has little value as a manure1 as it undergoes decomposition with extreme slowness4 ,it is a good mechanical addition to heavy soils1 and diminishes their tenacity2 and though its manurial effects are small1 it sooner or later undergoes decomposition1 and yields what valuable matters it contains4 ,the saw-dust of hard wood is to be preferred1 both because it contains more valuable matters than that of soft wood1 and because the absence of resinous matters permits its more rapid decomposition4 ,it is a useful absorbent of liquid manure1 and may be advantageously added to the dung-heap for that purpose4 ,manuring with ,fresh ,vegetable ,matter--,green ,manuring4--,the term green manuring is applied to the system of sowing some rapidly growing plant1 and ploughing it in when it has attained a certain size1 and the success attending it1 especially on soils poor in organic matters1 is very marked4 ,it is obvious that this mode of manuring can add nothing to the mineral matters contained in the soil1 and its utility must therefore be due to the plant gathering organic matters from the air1 which1 by their decomposition1 yield nitrogen and carbonic acid--the former to be directly made use of by subsequent crops1 the latter1 in all probability1 acting also on the soil1 and setting free its useful constituents4 ,hence those plants which obtain the largest quantity of their organic elements from the air ought to be most advantageous for green manuring4 ,the plants used for this purpose act also as a means of bringing up from the lower parts of the soil the valuable matters which exist in it out of reach of ordinary crops1 and mixing them again with the surface part4 ,many of the plants found most useful for green manuring send down their roots to a considerable depth2 and when they are ploughed in1 all the substances which they have brought up are of course deposited in the upper few inches of the soil4 ,vegetable matter when ploughed in in the fresh state1 also decomposes rapidly1 and is therefore able immediately to improve the subsequent crop2 and as this decomposition takes place in the soil without the loss of ammonia and other valuable matters1 which is liable to occur to a greater or less extent when they are fermented on the dung-heap1 it will be obvious that in no other mode can equally good results be obtained by its use4 ,many plants have been employed as green manure1 and different opinions have been expressed as to their relative values4 ,in the selection of any one for the purpose1 that should of course be taken which grows most rapidly1 and produces within a given time the largest quantity of valuable matters1 but no general rule can be given for the selection1 as the plant which fulfils those conditions best will differ in different soils and climates4 ,the plants most commonly employed in this country are spurry1 white mustard1 and turnips4 ,rye1 clover1 buckwheat1 white lupins1 rape1 borage1 and some others1 have been largely employed abroad4 ,some of these are obviously unfitted for the climate of the ,british ,islands2 and the others1 although they have been tried occasionally1 do not appear to have been very extensively employed4 ,the turnip is sown broadcast at the end of harvest1 and ploughed in after two months4 ,white mustard and spurry are employed in the same way as a preparation for winter wheat1 and with the best results4 ,the latter is sometimes sown as a spring crop in ,march1 ploughed in in ,may1 and another crop sown which is ploughed in in ,june1 and immediately followed by a third4 ,the effect of this treatment is such that the worst sands may be made to bear a remunerative crop of rye4 ,it is not easy to estimate the addition made by green manuring to the valuable matters contained in the soil1 but it is probably far from inconsiderable4 ,a crop of turnips1 cultivated on the ordinary agricultural system1 after two months' growth1 weighs between five and seven tons per acre1 and contains nitrogen equivalent to about #dh lbs4 of ammonia1 and half a ton of organic matters2 but nothing is known as to the quantity produced when it is sown broadcast1 and is not thinned1 although it must materially exceed this4 ,neither is it possible to determine the relative proportions derived from the soil and the air1 although it is1 in all probability1 dependent on the resources of the soil itself1--plants grown on a rich soil obtaining their chief supplies from it1 while1 on poorer soils1 a larger proportion is drawn from the atmosphere4 ,hence light and sandy soils are most benefited by green manuring1 partly on this account1 and partly also1 no doubt1 because the valuable inorganic matters1 which are so liable to be washed out of these soils1 are accumulated by the plants and retained in them in a state in which they are readily available for the subsequent crop4 ,sea-,weed4--,sea-weeds have been employed from time immemorial as a manure on the coasts of ,scotland and ,england1 in quantities varying from #aj to #bj tons per acre4 ,their action is necessarily similar to that of green manure ploughed in1 as they contain all the ordinary constituents of land plants4 ,the subjoined analyses of three of the most abundant species will sufficiently indicate their general composition4 ---------------------------------------- --------------------------------- ,,laminaria ,,digitata4 ,mixed ,weeds ,fucus ,fucus ---------------------------in the nodosus4 vesicu4- ,stem and state in losus ,collected ,frond which they in ,autumn4 collected actually in ,spring4are used ---------------------------------------- -------------------------------- ,water #gd4ca #gj4eg #hh4fi #gg4ca #hj4dd ,albuminous compounds #a4gf #b4ja #j4ic #c4cb #b4he ,fibre1 etc4 #ai4jd #bb4je #d4ib #aj4ci #f4dj ,ash #d4hi #e4cg #e4df #h4ih #aj4ca ---------------------------------------- ---------------- #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,nitrogen #j4bh #j4cb #j4ae #j4ec #j4de ,the ash consisted of ,stem4 ,frond4 ,peroxide of iron #j4be #j4ce #j4bj #j4ej #j4de #b4ce ,lime #i4fj #h4ib #g4ba #g4bi #d4fb #ah4ae ,magnesia #f4fe #e4hc #b4gc #e4ia #aj4id #f4dh ,potash #bj4jc #bj4ge #e4ee #aa4ia #ab4af #ab4gg ,chloride of potassium 444 444 #eh4db #bf4ei #be4hc #i4aj ,iodide of potassium #j4dd #j4bc #a4ea #b4ji #a4bb #a4fh ,soda #d4eh #f4ji 444 444 444 444 ,sulphuret of sodium,m #c4ff 444 444 444 444 444 ,chloride of sodium #bd4cc #bd4ha #ae4bi #cj4gg #ai4cd #bb4jh ,phosphoric acid #a4ga #b4ad #b4db #b4ff #a4ge #d4ei ,sulphuric acid #ba4ig #bh4ja #b4bc #h4hj #g4bf #f4bb ,carbonic acid #f4ci #b4bj #d4aa #b4di #ae4bc #ac4eh ,silicic acid #j4ch #j4fg #j4cc #j4ii #a4bj #c4jj ----- ------ ------ ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj ---------------------------------------- -------------------------------- ,the first four analyses give the composition of the weeds after they have been separated from all foreign substances2 the last1 that of the mixture taken from the heap just as it is used in ,orkney2 and its value is then enhanced by small shells and marine animals adhering to the plants1 which increase the amount of phosphoric acid and nitrogen4 ,the ease with which all sea-weeds pass into a state of putrefaction1 adapts them in a peculiar manner to the manurial requirements of a cold and damp climate4 ,the rapidity of their decomposition is such1 that when spread on the land they are seen to soften and disappear in a short time4 ,they form therefore a rapid manure1 and their effects are said to be confined to the crop to which they are applied2 but this is probably due to the fact1 that they are chiefly used in inferior sandy soils1 in which any manure is rapidly exhausted4 ,in good soils there is no reason why their effect should not be as lasting as that of farm-yard manure1 which1 in many particulars1 they considerably resemble4 ,the method of applying sea-weeds most generally in use1 is to spread them on the soil1 and plough them in after putrefaction has commenced1 and it is on the whole the most advantageous4 ,but they are sometimes composted with lime and earth1 or mixed with farm-yard manure1 and occasionally1 also1 they are used as a top-dressing to grass land4 ,on some parts of the western coast of ,scotland and in the ,hebrides1 sea-weed is the chief manure4 ,it gives excellent crops of potatoes1 but they are said to be of inferior quality1 unless marl or shell-sand is employed at the same time4 ,leaves may be used as a manure1 simply by ploughing them in1 by composting them with lime1 or by adding them to the manure heap4 ,peat4--,as a source of organic matter1 peat may be used with advantage1 especially on soils in which it is naturally deficient4 ,dry peat of good quality contains about one per cent of nitrogen1 and a quantity of ash varying from five to twenty per cent4 ,these substances1 however1 become available very slowly1 owing to the tardy decay of peat in its natural state2 and in order to make it useful1 it is necessary to compost it with lime1 or to mix it with farm-yard manure1 or some readily putrescible substance1 so that its decomposition may be accelerated4 ,it may be most advantageously used as an absorbent of liquid manure1 and on this account1 forms a useful addition to the manure heap4 ,the observations which have been made regarding the use of these substances1 lead directly to the inference that all vegetable matters possess a certain manurial value1 and that they ought to be carefully collected and preserved4 ,in fact1 the careful farmer adds everything of the sort to his manure heap1 where1 by undergoing fermentation along with the manure1 their nitrogen becomes immediately available to the plant2 while the seeds of weeds are destroyed during the fermentation1 and the risk of the land being rendered dirty by their springing up when the manure comes to be used is prevented4 ,,footnotes3 ,footnote ,m3 ,the presence of sulphuret of sodium in this case is due to the difficulty of completely burning the ash4 ,it exists in the plant as sulphate of soda4 ,,chapter ,x4 ,,composition ,,and ,,properties ,,of ,,animal ,,manures4 ,manures of animal origin are generally characterized by the large quantity of nitrogen they contain1 which causes them to undergo decomposition with great rapidity1 and to yield the greater part of their valuable matters to the crop to which they are applied4 ,guano4--,by far the most important animal manure is guano1 which is composed of the solid excrements of carnivorous birds in a more or less completely decomposed state1 and is accumulated in immense quantities on the coasts of ,south ,america and other tropical countries4 ,it has been used as a manure in ,peru from time immemorial1 but the accounts given by the older travellers of its marvellous effects were considered to be fabulous1 until ,humboldt1 from personal observation1 confirmed their statements4 ,it was first imported into this country in #ahdj1 in which year a few barrels of it were brought home2 and from that time its importation rapidly increased4 ,soon after large deposits of it were found in ,ichaboe2 and it has since been brought from many other localities4 ,the quantity of guanos of all kinds imported into this country and retained for home consumption now exceeds #bdj1jjj tons a year4 ,the value of guano differs greatly according to the extent to which its decomposition has gone1 and this is chiefly dependent on the climate of the locality from which it is obtained4 ,when deposited in the rainless districts of ,peru it still retains some of the uric acid and the greater part of the ammonia naturally existing in it1 and the quantity which has escaped by decomposition is unimportant4 ,but that obtained from other districts has suffered a more or less complete decomposition according to the humidity of the climate1 which reduces the quantity of organic matters and ammonia1 until1 in some varieties1 they are so small as to be of little importance4 ,the following are minute analyses of three specimens of ,peruvian guano1 shewing all the different constituents it contains1 and the amount of difference which may exist3-- ,i4 ,,ii4 ,,iii4 ,urate of ammonia #aj4gj #i4j #c4bd ,oxalate of ammonia #ab4ch #aj4f #ac4ce ,oxalate of lime #e4dd #g4j #af4cf ,phosphate of ammonia #ai4be #f4j #f4de ,phosphate of magnesia and ammonia 444 #b4f #d4bj ,sulphate of potash #d4ej #e4e #d4bc ,sulphate of soda #a4ie #c4h #a4ab ,sulphate of ammonia #c4cf 444 444 ,muriate of ammonia #d4ha #d4b #f4ej ,phosphate of soda 444 444 #e4bi ,chloride of sodium 444 444 #j4aj ,phosphate of lime #ae4ef #ad4c #i4id ,carbonate of lime #a4hj 444 444 ,sand and alumina #a4ei #d4g #e4hj ,water #i4ad #cb4c #bc4db ,undetermined humus-like organic #aj4jj matters ------ ----- ------ #ajj4dh #ajj4j #ajj4jj ,these analyses illustrate two points--first1 that in some samples the decomposition has advanced to a greater extent than in others2 for we observe that the quantity of uric acid1 or rather of urate of ammonia1 is greatly less in the last analysis than in the other two1 and much smaller than in the fresh dung1 which contains from #ej to #gj per cent of uric acid2 and secondly1 that guano is rich in all the constituents of the plant1 but especially in ammonia1 the best form in which nitrogen can be supplied1 in uric acid which by decomposition yields ammonia1 and in phosphoric acid4 ,but such analyses are too elaborate for ordinary purposes1 and much less convenient for comparison and for estimating the value of the guano than the shorter analysis commonly in use1 which gives the water1 the loss by ignition 7that is1 the sum of the organic matters and ammoniacal salts71 the phosphates1 the alkaline salts1 and the quantity of phosphoric acid contained in them1 and existing there in a state similar to that in which it is found in the soluble phosphates of a superphosphate4 ,in addition to these1 the quantities of sand and other less valuable ingredients are also stated4 ,in the subjoined tables the composition of a great variety of different kinds of guano is given4 ,most of these are averages deduced from a considerable number of analyses of good samples4 ,those of some kinds of guano1 such as ,peruvian1 which present a considerable amount of uniformity1 afford a sufficiently accurate idea of the general composition of the variety1 but in other cases they are of less value1 because the imports of different seasons1 and even of different cargoes1 differ so greatly in composition that no proper average can be made4 ,several of these varieties are already exhausted1 the importation of others has ceased1 and new varieties are constantly being introduced4 ,table showing the ,average ,composition of different varieties of ,guano4 ---------------------------------------- ---------------------------------- ,angamos4,peru- ,,ichaboe4 ,bolivian or ,upper vian4 ,peruvian4 -------------------------------------- ,old4 ,new4 ,old4 ,government4,inferior ---------------------------------------- ------------------------------- ,water #ab4cf #ac4gc #bd4ba #ah4hi #ab4ee #af4dd #ad4ae ,organic matter and ammoniacal #ei4ib #ec4af #ci4cj #cb4di #ce4hi #ab4bh #bf4ad salts ,phosphates #ag4ja #bc4dh #cj4jj #ai4fc #bg4fc #ef4ji #bc4ac ,sulphate of lime 444 444 444 444 444 444 #i4fe ,carbonate of lime 444 444 444 444 444 444 #ab4hg ,alkaline salts #g4bj #g4ig #d4ai #h4hb #ae4bi #aa4cc #e4ig ,sand #c4ea #a4ff #b4cj #f4gb #h4fd #b4ha #h4ji ---------------------------------------- ------------ #ajj4jj #ajj4jj #ajj4jjajj4jjajj4jjajj4jj #ajj4jj ,ammonia #ba4aj #ag4jj #h4ej #aj4db #h4ii #b4eg #c4bf ,phosphoric acid in alkaline #a4bj #b4ej 444 444 444 #c4aa 444 salts ---------------------------------------- ------------------------------- ---------------------------------------- --------------------------- ,pacquico4,latham ,saldanha,australian4,kooriamooria4 ,island4,bay4 ---------------------------------------- --------------------------- ,water #h4ch #bd4if #ba4jc #ac4bj #h4ia ,organic matter and ammoniacal #bc4aj #aj4if #ad4ic #ac4gg #g4gb salts ,phosphates #cb4cf #ed4dg #ef4dj #dd4dg #dd4ae ,sulphate of lime #b4ib #b4hb 444 #d4ee #c4ai ,carbonate of lime 444 #b4bj 444 #h4hb #c4cg ,alkaline salts #be4dc #d4jf #f4aj #g4cd #aa4bc ,sand #g4ha #j4ea #a4ed #g4he #ba4dc ---------------------------------------- -------- #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,ammonia #f4eh #a4bf #a4fb #a4ja #j4db ,phosphoric acid in alkaline #c4ej 444 444 444 444 salts ---------------------------------------- --------------------------- ---------------------------------------- ------ ,patagonian4,chilian4,mexican4 ---------------------------------------- ------ ,water #bj4fa #ad4hi #ah4hj ,organic matter and ammoniacal #ai4gb #af4ha #ab4hh salts ,phosphates #cj4ff #cf4ij #ah4ch ,sulphate of lime #a4cj 444 #bg4gi ,carbonate of lime #c4jf #aj4bh 444 ,alkaline salts #g4ja #f4hd #af4ie ,sand #ag4jd #ad4bf #e4bj --------------------------- #ajj4jj #ajj4jj #ajj4jj ,ammonia #b4fi #a4db #j4db ,phosphoric acid in alkaline #c4jj 444 444 salts ---------------------------------------- ------ ,table shewing the ,composition of some of the less common varieties of ,guano4 ,,note4--,the numbers in this ,table are mostly derived only from a single analysis and have no value as determining the average composition of these ,guanos1 but they serve to give a general idea of their value4 ---------------------------------------- ---------------------------- ,sea ,indian4 ,holme's ,ascension ,possession ,bear ,bird ,island4 ,island4 ,bay4 ,island4 ---------------------------------------- ---------------------------- ,water #cj4hb #bc4fb #be4jj #ae4ig #aj4ib ,organic matter and ammoniacal #ca4gh #fj4je #cb4aj #bc4ae #ae4db salts ,phosphates #bd4cc #g4ah #bg4cf #cb4ed #df4da ,sulphate of lime #c4hd 444 444 444 #g4df ,carbonate of lime #j4eh #b4gi 444 444 444 ,alkaline salts #g4ch #e4eh #h4hb #ae4ib #f4ae ,sand #a4bg #j4gh #f4gb #ab4db #ac4fd ---------------------------------------- --------- #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,ammonia #aj4de #aj4bg #g4ge #f4jf #a4cd ,phosphoric acid in alkaline 444 444 444 #a4hb 444 salts ---------------------------------------- ---------------------------- ---------------------------------------- ------------- ,algoa ,new ,bird's ,leone ,bay4 ,island4 ,island4 ,island4 ---------------------------------------- ------------- ,water #cj4ee #bh4gh #af4eb #bc4fe ,organic matter and ammoniacal #f4he #ac4gh #ad4hd #d4bg salts ,phosphates #ba4bd #bb4df #be4ba #ac4eh ,sulphate of lime #cf4db 444 #dj4dg #bi4ie ,carbonate of lime 444 #ac4gh 444 444 ,alkaline salts #c4cb #ab4fb #a4af #e4dj ,sand #a4fb #aa4eh #a4hj #bc4ae ---------------------------------- #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,ammonia #j4ed #j4hd #a4bf #j4fg ,phosphoric acid in alkaline 444 444 444 444 salts ---------------------------------------- ------------- ,on examining the tables given above1 it is obvious that guanos may be divided into two classes1 the one characterized by the abundance of ammonia1 the other by that of phosphates2 and which1 for convenience sake1 may be called ammoniacal and phosphatic guanos4 ,peruvian and ,angamos are characteristic of the former1 and ,saldanha ,bay and ,bolivian of the latter class4 ,the value of these two classes of guano differs materially1 and they are also applicable under different circumstances1 but to these points reference will afterwards be made4 ,very special precautions are necessary on the part of the farmer in order to insure his obtaining a guano which is not adulterated1 and of good quality if genuine4 ,in the case of ,peruvian guano1 which is tolerably uniform in its qualities1 it is possible to form some opinion by careful examination1 and the following points ought to be attended to3 #ast1 ,the guano should be light coloured4 ,if it is dark1 the chances are that it has been damaged by water4 #b;d1 ,it should be dry1 and when a handful is well squeezed together it should cohere very slightly4 #c;d1 ,it should not have too powerful an ammoniacal odour4 #dth1 ,it should contain lumps1 which1 when broken1 appear of a paler colour than the powdery part of the sample4 #eth1 ,when rubbed between the fingers it should not be gritty4 #fth1 ,a bushel of the guano should not weigh more than from #ef to #fj lbs4 ,these characters must not1 however1 be too implicitly relied on1 for they are all imitated with wonderful ingenuity by the skilful adulterator1 and they are applicable only to ,peruvian guano2 the others being so variable that no general rules can be given for determining whether they are genuine4 ,neither are they so precise as to enable us to give any opinion regarding the relative values of several samples where all are genuine4 ,the only way in which adulteration can with certainty be detected1 and the value of different guanos be determined1 is by analysis1 and the importance of this can easily be illustrated4 ,in the table above1 the average composition of the different guanos is given2 but in order to shew how much individual cargos may differ from the mean1 we give here analyses of samples of the highest and lowest quality of the genuine guanos of most importance3 ---------------------------------------- ---------------------------------- ,angamos4 ,peruvian4 ,bolivian4 ---------------------------------------- ------------ ,highest4 ,lowest4 ,highest4 ,lowest4 ,highest4 ,lowest4 ---------------------------------------- ------------ ,water #ab4fj #g4ji #aj4cg #ba4di #aa4ec #af4bj ,organic matter and ammoniacal #fe4fb #ej4hc #ee4gc #df4bf #aa4ag #ab4hf salts ,phosphates #aj4hc #h4gj #be4bj #ah4ic #fb4ii #eb4ie ,alkaline salts #g4ej #af4cj #g4ej #aj4fd #i4ic #ac4hc ,sand #c4de #ag4jh #a4bj #b4fh #d4ch #d4af ---------------------------------------- ------------ #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,ammonia #be4cc #ag4ae #ah4ie #ad4fe #a4hi #b4bc ---------------------------------------- ------------------------------- ,the differences are here exceedingly large2 and when the values of the two ,peruvian guanos are calculated according to the method to be afterwards described1 it appears that the highest exceeds the lowest in value by nearly ,l#c per ton4 ,of course1 this is an extreme case1 but it is no uncommon occurrence to find a difference of ,l#a or even ,l#b per ton between the values of cargos of ,peruvian guano1 which are sold at the same price4 ,the adulteration of guano is carried on to a very large extent2 and though perhaps not quite so extensively now as it was some years since1 it is only kept in check by the utmost vigilance on the part of the purchaser4 ,the chief adulterations are a sort of yellow loam very similar in appearance to guano1 sand1 gypsum1 common salt1 and occasionally also ground coprolites and inferior guano4 ,these substances are rarely used singly1 but are commonly mixed in such proportions as most closely to imitate the colour and general appearance of the genuine article4 ,the extent to which the adulteration is carried may be judged of from the following analyses taken at random from those of a large number of guanos1 all of which were sold as first-class ,peruvian4 ,water #ab4he #ae4ai #ab4jf #bg4hf #f4cb ,organic matter and ammoniacal salts #bf4hd #dd4ca #cd4ad #cj4da #bg4db ,phosphates #ae4ed #bj4ie #bb4jh #bb4ag #cc4fa ,sulphate of lime 444 444 #aa4jh 444 #bb4aa ,alkaline salts #f4jg #i4dj #ab4ha #g4ib #bb4ej ,sand #ch4gj #aj4ae #g4hc #a4fd #aj4ae ------ ------ ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,ammonia #i4cd #ac4ij #i4gg #h4fd #i4gf ,in all those cases a very large depreciation in the value has taken place1 and several of them are worth considerably less than half the price of the genuine guano1 while they are generally offered for sale at about ,l#a under the usual price4 ,the adulteration is chiefly practised in ,london1 and cases occasionally occur which can be traced to ,liverpool and other places2 but it always takes place in the large towns1 because it is only there that facilities exist for obtaining the necessary materials and carrying it out without exciting suspicion4 ,the sophisticated article then passes into the hands of the small country dealers1 to whom it is sold with the assurance that it is genuine1 and analysis quite unnecessary4 ,in other instances1 adulterated and inferior guanos are sold by the analysis of a genuine sample1 and sometimes an analysis is made to do duty for many successive cargos of a guano which1 though all obtained from one deposit1 may differ excessively in composition4 ,in order to insure obtaining a genuine guano1 it is above all things important to deal only with a person of established character1 who will generally1 for his own sake1 satisfy himself that the article he vends is genuine and of good quality2 and it is always important that the buyer should examine the analysis1 and in all cases where there is the slightest doubt1 should ascertain that the bulk sent corresponds with it4 ,in the case of a ,peruvian guano1 a complete analysis is not necessary for this purpose2 but an experienced chemist1 by the application of a few tests1 can readily ascertain whether the sample is genuine4 ,where the difference in value between different samples is required1 a complete analysis is necessary1 and this is indispensable in the case of the inferior guanos4 ,many of these are obtained from deposits of limited extent1 and in loading it considerable quantities of the subjacent soil are taken up1 so that very great differences may exist even in different parts of the same cargo4 ,nor must it be forgotten that1 except in the case of ,peruvian1 the name is no guarantee for the quality of the guano1 even if genuine4 ,peruvian guano is all obtained from the same deposits1 those of the ,chincha ,islands1 but the guanos which are brought into the market under the name of ,patagonian1 ,chilian1 etc41 are obtained from a great variety of deposits scattered along the coasts of these countries1 sometimes at a distance of several hundred miles from each other1 and which have been accumulated under totally different circumstances4 ,in illustration of this1 it is only necessary to refer to the subjoined analysis of samples1 all of which ,i believe to be genuine as imported1 and which were sold under the name of ,upper ,peruvian ,guano4 ,i4 ,,ii4 ,,iii4 ,water #g4hj #f4fe #h4he ,organic matter and ammoniacal salts #aj4he #ai4af #aj4bj ,phosphates #fg4jj #bj4da #ag4aj ,carbonate of lime 444 #ba4ae 444 ,alkaline salts #aa4aj #e4ca #fa4cj ,sand #c4be #bg4cb #b4ee ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj ,ammonia #b4bi #e4gc #a4dh ,phosphoric acid in the alkaline salts #b4bd 444 #a4gj ,equal to phosphate of lime #d4hi 444 #c4gj ,with the exception of ,peruvian1 the supply of good guanos of uniform composition is by no means large1 and phosphatic guanos of good quality are now especially rare4 ,the ,saldanha ,bay1 and other similar deposits1 have been exhausted1 and few guanos of equally good quality have been lately discovered4 ,there is no doubt1 however1 that such guanos are very useful1 and if obtained in large quantity1 and of uniform composition1 would be used to a much larger extent than they at present are4 ,the value and use of guano are now so well understood1 that it is scarcely necessary to enlarge on the mode of its application4 ,peruvian guano owes its chief value to its ammonia and phosphates1 but it also contains potash1 soda1 and all the other constituents of plants in small quantity1 although in a readily available condition1 as is seen in the detailed analysis given in page #bje4 ,in other guanos which have undergone more complete decomposition1 and from which the soluble matters have been more or less completely exhausted by rain1 the alkaline salts1 or at least the potash they originally contained1 have almost entirely disappeared4 ,hence an important difference between ,peruvian guano and most other varieties4 ,the former can be used as a complete substitute for farm-yard manure1 and excellent crops of turnips and potatoes can be raised by means of it alone1 and at a less cost than with ordinary dung4 ,but though this may be done1 and in many cases is attended with great economic advantages1 it is a practice that cannot be recommended for general use1 because the quantity of valuable matters contained in the usual application of guano is much smaller than in farm-yard manure1 and the probability is that it would not1 if used alone during a succession of years1 be sufficient to maintain the soil permanently in a high state of fertility4 ,five cwt4 of ,peruvian guano1 which is a liberal application per acre1 contains about #ie lbs4 of ammonia1 and #acj of phosphates1 while #bj tons of good farm-yard manure contain #cab of ammonia1 and about the same quantity of phosphates1 and when the other constituents1 such as potash and soda1 are compared with those in guano1 the difference is still more striking4 ,on the other hand1 guano is a rapidly acting manure2 its constituents are in a condition in which they are more immediately accessible by the plant1 and its immediate effect is far more marked1 as it is chiefly expended on the crop to which it is applied4 ,it has indeed been alleged that it produces no effects on the subsequent crops1 but this opinion can scarcely be considered as well founded4 ,in no case does the crop raised by means of it contain the whole of the ammonia or phosphates present in the manure1 and the unappropriated quantity1 though it may1 and probably does1 escape from the lighter soils1 must be retained and preserved for the use of subsequent crops by heavy and retentive clay soils4 ,the general inference is1 that though guano may at an emergency be used as an entire substitute for farm-yard manure1 the practice is one to be generally avoided4 ,when1 however1 as occasionally happens after a long continued use of farm-yard manure1 organic matters have accumulated in the soil1 and passed into an inert condition1 then ,peruvian guano may be used alone with very great advantage4 ,in all cases the rapidity of the action of guano makes it an important auxiliary of farm-yard manure1 and it is in this way that it may be most advantageously employed4 ,experience has shewn that one-half the farm-yard manure may be replaced by guano with the production of a larger crop than by the former alone in its full quantity4 ,the proportion of guano usually employed is from three to five cwt41 and it is alleged that a much larger quantity produces prejudicial effects on the subsequent crops1 although it is not very easy to see on what this depends4 ,the variety of guano to be selected must depend to a great extent on the use to which it is to be put4 ,peruvian guano is most advantageously applied as a top-dressing to young corn and particularly to oats4 ,for the turnip1 the ammoniacal guanos were formerly preferred1 and on strong soils1 under good cultivation1 their effects are excellent1 but on light soils they are less applicable1 their soluble salts being more rapidly washed out1 and their effects lost1 and in these cases they are surpassed by the phosphatic guanos4 ,no definite rules can be given for determining the soils on which these different varieties are most applicable1 but each individual must determine by experiment that which best suits his own farm2 and the inquiry is of much importance to him1 as1 of course1 if the phosphatic guanos will answer as well as the ammoniacal1 there is a large saving in the cost of the manure4 ,a very excellent practice is to employ a mixture of equal parts of the two sorts of guano4 ,pigeons' ,dung4--,the dung of all birds1 which more or less closely resembles guano1 may be employed with much advantage as a manure1 but that of the pigeon and the common fowl are the only ones which can be got in quantity4 ,pigeons' dung1 according to ,boussingault1 contains #h4c per cent of nitrogen1 equivalent to #aj4j of ammonia4 ,its value1 therefore1 will be more than half that of guano1 but it varies greatly1 and a sample imported from ,egypt into this country1 and analysed by ,professor ,johnston1 contained only #e4d per cent of ammonia4 ,hens' dung has not been accurately analysed1 but its value must be about the same as pigeons'4 ,urate and ,sulphated ,urine4--,we have already discussed the urine of animals1 in reference to farm-yard manure4 ,but human urine1 the composition of which was then stated1 is of much higher value than that of the lower animals1 and many attempts have been made to preserve and convert it into a dry manure4 ,urate is prepared by adding gypsum to urine1 and collecting and drying the precipitate produced4 ,it contains a considerable quantity of the phosphoric acid of the urine1 but very little of its ammonia2 and as the principal value of urine depends on the latter1 it is necessarily a very inefficient method of turning it to account4 ,a better method has been proposed by ,dr4 ,stenhouse1 who adds lime-water to the urine1 and collects the precipitate1 which1 when dried in the air1 contains #a4ia per cent of nitrogen1 and about #da per cent of phosphates4 ,this method is subject to the same objection as that by which urate is made1 namely1 that the greater part of the ammonia is not precipitated4 ,this might probably be got over to some extent by the addition of sulphate of magnesia1 or1 still better1 of chloride of magnesium1 which would throw down the phosphate of magnesia and ammonia4 ,by much the best mode of employing urine is in the form of sulphated urine1 which is made by adding to it a sufficient quantity of sulphuric acid to neutralize its ammonia1 and evaporating to dryness4 ,in this form all the valuable constituents are retained1 and excellent results are obtained from it4 ,its effects1 though mainly attributable to its ammonia1 are also in part dependent on the phosphates and alkaline salts which it contains2 and it is therefore capable of supplying to the plant a larger number of its constituents than the animal matters already mentioned4 ,night-,soil and ,poudrette4--,the value of night-soil1 which is well known1 depends partly on the urine1 and partly on the faeces of which it is formed4 ,its disagreeable odour has prevented its general use1 and various methods have been contrived both for deodorising and converting it into a solid and portable form4 ,the same difficulties which beset the conversion of urine into the solid form occur here1 and in most of the methods employed the loss of ammonia is great4 ,it is sometimes mixed with lime or gypsum1 and dried with heat1 and sometimes with animal charcoal or peat charcoal4 ,the manufacture of a manure from night-soil1 called poudrette1 has long been practised in the neighbourhood of ,paris and other continental towns4 ,the process employed at ,montfaucon and at ,bondy is very simple4 ,the contents of the cesspools are conveyed to the work in large barrels1 which are then emptied into tanks capable of containing the accumulation of several months4 ,when filled they are allowed to stand for some time1 during which the smell diminishes and the contents become nearly dry4 ,the residue is then dug out and mixed with ashes1 dry loam1 charcoal powder1 peat1 peat-charcoal1 saw-dust1 and other matters1 so as to deodorize it1 and render it sufficiently dry for transport4 ,its general composition may be judged of from the subjoined analyses of samples from different places3-- ,montfaucon4 ,bondy4 ,dresden4 ,american4 ,water #bh4jj #ac4fj #ai4ej #ci4ig ,organic matters #bi4jj #bd4aj #bj4hj #bj4eg ,phosphates #g4fe #d4if #e4dj #a4hh ,carbonates of lime and ,magnesia1 alkaline #g4ce #ad4ad #aa4cj #g4fc salts1 etc4 ,sand #bh4jj #dc4bj #dc4jj #bi4ie ------ ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,ammonia #a4ed #a4ih #b4fj #a4bc ,these analyses shew sufficiently the extent to which the animal matters have been mixed with valueless driers1 the second and third samples containing considerably more than half their weight of worthless matters4 ,hair1 ,skin1 and ,horn4--,the refuse of manufactories in which these substances are employed1 are frequently used as manures4 ,they are highly nitrogenous substances1 and owe their entire value to the nitrogen they contain1 their inorganic constituents being in too small quantity to be of any importance1 wool and hair having only #b per cent1 and horn #j4g per cent of ash4 ,in the pure and dry state1 and after subtraction of the ash1 their composition is1-- ,skin4 ,human hair4 ,wool4 ,horn4 ,carbon #ej4ii #ej4fe #ej4fe #ea4ii ,hydrogen #g4jg #f4cf #g4jc #f4gb ,nitrogen #ah4gb #ag4ad #ag4ga #ag4bh ,oxygen #bc4bb #bj4he #bd4fa #bd4ja ,sulphur 444 #e4jj ------ ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj #ajj4jj ,it rarely if ever happens1 however1 that the refuse offered for sale as a manure is pure4 ,it always contains water1 sand1 and other foreign matters4 ,woollen rags are mixed with cotton which has no manurial value1 and the skin refuse from tan-works contains much lime4 ,due allowance must therefore be made for such impurities which are sometimes present in very large quantity4 ,refuse horse hair generally contains #aa or #ab per cent of nitrogen4 ,woollen rags of good quality contain #ab4g per cent of nitrogen2 woollen cuttings about #ad2 and what is called shoddy only #e4e per cent4 ,horn shavings are extremely variable in their amount of nitrogen2 when pure1 they sometimes contain as much as #ab4e per cent1 but a great deal of the horn shavings from comb manufactories1 etc41 contain much sand and bone dust1 by which their percentage of nitrogen is greatly diminished1 and it sometimes does not exceed #e or #f per cent4 ,all these substances are highly valuable as manures1 but it must be borne in mind that they undergo decomposition very slowly in the soil1 and hence are chiefly applicable to slow growing crops1 and to those which require a strong soil4 ,woollen rags have been largely employed as a manure for hops1 and are believed to surpass every other substance for that crop4 ,as a manure applicable to the ordinary purposes of the farm they have scarcely met with that attention which they deserve1 probably because their first action is slow and the farmer is more accustomed to look to immediate than to future results2 but they possess the important qualification of adding permanently to the fertility of the soil4 ,blood is a most valuable manure1 but it is not much employed in this country1 at least in the neighbourhood of large towns1 as there is a demand for it for other purposes1 and it can rarely be obtained by the farmer in large quantity1 and at a sufficiently low price4 ,in its natural state it contains about #c per cent of nitrogen1 and after being dried up1 the residue contains about #ae per cent4 ,it is best used in the form of a compost with peat or mould1 and this forms an excellent manure for turnips1 and is also advantageously applied as a top-dressing to wheat4 ,flesh4--,the flesh of all animals is useful as a manure1 and is especially distinguished by the rapidity with which it undergoes decomposition1 and yields up its valuable matters to the plant4 ,it is rarely employed in its natural state1 but horse flesh was at one time converted into a dry and portable manure1 although1 ,i understand1 this manufacture is not now prosecuted4 ,the dead animal after being skinned is cut up and boiled in large cauldrons until the flesh is separated from the bones4 ,the latter are removed1 and the flesh dried upon a flat stove4 ,the flesh as sold has the following composition3-- ,water #ab4ag ,organic matter #gh4dd ,phosphate of lime1 etc4 #c4hb ,alkaline salts #c4fd ,sand #a4ic ------ #ajj4jj ,nitrogen #i4bb ,ammonia to which the nitrogen is equivalent #aa4bj ,the dried flesh and small bones of cattle1 from the great slaughtering establishments of ,south ,america1 was at one time imported into this country under the name of flesh manure4 ,its composition was-- ,water #i4je ,fat #aa4ac ,animal matter #ci4eb ,phosphate of lime #bh4gd ,carbonate of lime #c4ha ,alkaline salts #j4eg ,sand #g4ah ------ #ajj4jj ,nitrogen #e4ef ,ammonia to which the nitrogen is equivalent #f4fg ,but owing to the large proportion of phosphates contained in it1 it may be most fairly compared with bones4 ,it is not now imported1 the results obtained from its use being said not to have proved satisfactory1 although this statement appears very paradoxical4 ,fish have been employed in considerable quantity as a manure4 ,that most extensively employed in this country is the sprat1 which is occasionally caught in enormous quantities on the ,norfolk coast1 and used as an application for turnips4 ,they are sold at #h;d4 per bushel1 and their composition is-- ,water #fd4f ,organic matter #cc4c ,ash #b4a ----- #ajj4j ,nitrogen #a4ij ,phosphoric acid #j4ia ,the refuse of herring and other fish-curing establishments1 whales' blubber1 and similar fish refuse1 are all useful as manure1 and are employed whenever they can be obtained4 ,they are not usually employed alone1 but are more advantageously made into composts with their own weight of soil1 and allowed to ferment thoroughly before being applied4 ,many attempts have been made to convert the offal of the great fish-curing establishments1 and the inedible fish1 of which large quantities are often caught1 into a dry manure1 which has received the name of fish guano4 ,the processes employed have consisted in boiling with sulphuric acid and other agents1 and then evaporating1 or sometimes by simply drying up the refuse by steam heat4 ,a manure made in this way proved to have the following composition3-- ,water #h4jj ,fatty matters #g4bj ,nitrogeneous organic matters #ga4df ,phosphate of lime #h4gj ,alkaline salts #c4hj ,sand #j4hd ------ #ajj4jj ,nitrogen #aa4be ,equal to ammonia #ac4fh ,phosphoric acid in the alkaline salts1 #j4fe equal to #a4da phosphate of lime ,the expense of manufacturing manures of this description has hitherto acted as a barrier to their introduction4 ,in this country several manufactories have been established1 but either owing to this cause1 or to the difficulty of obtaining sufficiently large and uniform supplies of the raw material1 some of them have not proved successful1 but a manufactory is now in operation in ,norway1 which exports the manure to ,germany4 ,it is probable that most of the processes used in this country failed because they were too costly1 and it is much to be desired that the subject should be actively taken up4 ,it is said that the refuse from the ,newfoundland fisheries is capable of yielding about #aj1jjj tons of fish guano annually2 and the quantity obtainable on our own coasts is also very considerable4 ,bones4--,bones have been used as a manure for a long period1 but they first attracted the particular attention of agriculturists from the remarkable effects produced by their application on the exhausted pasture lands of ,cheshire4 ,during the present century they came into general use on arable land1 and especially as a manure for turnips2 and they are now imported in large quantities from the continent of ,europe4 ,the bones used in agriculture are chiefly those of cattle1 but sheep and horse bones are also employed4 ,they do not differ much in quality when genuine4 ,the subjoined analysis is that of a good sample4 ,water #f4bj ,organic matter #ci4ac ,phosphate of lime #dh4ie ,lime #b4eg ,magnesia #j4cj ,sulphuric acid #b4ee ,silica #j4cj ------ #ajj4jj ,ammonia which the organic matter is capable of yielding #d4hj ,in general1 bones may be said to contain about half their weight of phosphate of lime1 and #aj or #ab per cent of water4 ,but1 in addition to their natural state1 they are met with in other forms in commerce1 in which their organic matter has been extracted either by boiling or burning4 ,the latter is especially common in the form of the spent animal charcoal of the sugar refiners1 which usually contains from #gj to #hj per cent of phosphate of lime1 but when deprived of their organic matter1 they may be more correctly considered under the head of mineral manures4 ,from the analysis given above1 it is obvious that the manurial value of bones is dependent partly on their phosphates and partly on the ammonia they yield4 ,it has been common to attribute their entire effects to the former1 but this is manifestly erroneous2 and although there are no doubt cases in which the former act most powerfully1 the benefit derived from the ammonia yielded by the organic matter is unequivocal4 ,when the phosphates only are of use1 burnt bones or the spent animal charcoal of the sugar refiners are to be preferred4 ,at their first introduction1 bones were applied in large fragments1 and in quantities of from #bj to #cj cwt41 or even more1 per acre1 but as their use became more general they were gradually employed in smaller pieces1 until at last they were reduced to dust1 and it was found that1 in a fine state of division1 a few hundredweights produced as great an effect as the larger quantity of the unground bones4 ,even the most complete grinding which can be attained1 however1 leaves the bones in a much less minute state of division than guano1 and they necessarily act more slowly than it does1 the more especially as they contain no ready-formed ammonia4 ,they may be still further reduced by fermentation1 which acts by decomposing the organic matter1 and causing the production of ammonia2 but not as is frequently1 though erroneously supposed1 by converting the phosphates into a soluble condition1 for this does not occur to any extent1 and their more rapid action is solely due to the partial decomposition of the organic matter1 by which it is brought into a condition capable of undergoing a more rapid change in the soil4 ,the rapidity of action of bones is still more promoted by solution in sulphuric acid1 by which they are converted into the form of dissolved bones or superphosphate4 ,at the present moment1 however1 very little of the superphosphates sold in the market are made exclusively from bones in their natural state1 by far the larger portion being manufactured from mineral phosphates1 or from bones after destruction of their organic matter1 sometimes with the addition of small quantities of unburnt bones1 but more frequently of sulphate of ammonia1 to yield the requisite quantity of ammonia4 ,these substances may therefore be best considered under the head of mineral manures4 ,,chapter ,,xi4 ,,composition ,,and ,,properties ,,of ,,mineral ,,manures4 ,mineral manure is a term which is now used with great laxity4 ,in its strict sense1 it means manures which contain only1 and owe their exclusive value to the presence of1 those substances which go to make up the inorganic part or ash of plants4 ,it has1 however1 been usually taken to include all saline matters1 and especially the compounds of ammonia and nitric acid1 which are indebted for their manurial effects to the nitrogen they contain2 and thus is so far incorrect4 ,it would1 however1 be manifestly impossible to arrange these compounds with any degree of accuracy among either animal or vegetable manures1 and hence the necessity of including them amongst those which are strictly mineral4 ,the most important practical distinction between them and the substances discussed in the two preceding chapters is1 that the latter generally contain the whole or the greater part of the constituents of plants4 ,even bones yield a certain quantity of alkalies1 magnesia1 sulphuric acid1 and chlorine1 and may in some sense be considered as a general manure4 ,but those to which the term mineral manure is applied for the most part contain only one or two of the essential elements of plants1 and hence cannot be applied as substitutes for the substances already discussed1 although they are frequently most important additions to them4 ,sulphate and ,muriate of ,ammonia4--,these and other salts of ammonia have been tried experimentally as manures1 and it has been ascertained that they may all be used with equal success2 but as the sulphate is by much cheaper1 it is that which probably will always be employed to the exclusion of every other4 ,it contains1 when pure1 #be4g per cent ammonia4 ,it is now manufactured of excellent quality for agricultural use1 and when good1 contains from #ie to #ig per cent of actual sulphate1 the remainder consisting chiefly of moisture and a small quantity of fixed residue2 but specimens are occasionally met with containing as much as #aj per cent of impurities1 which1 as its price is high1 makes a material difference in its value4 ,inferior descriptions are also occasionally sold1 among which is a variety distinguished by containing a large quantity of water and fixed salts1 although it appears to the eye a good article4 ,its composition is-- ,i4 ,,ii4 ,water #i4je #e4gg ,sulphate of ammonia #gi4fc #he4ba ,fixed salts #aa4ag #i4jb ------ ------ #ajj4jj #ajj4jj ,ammonia #bj4ee #ba4id ,an article called sulphomuriate of ammonia is also sold for agricultural use4 ,it is obtained as a refuse product in the manufacture of magnesia1 and is a mixture of sulphate and muriate of ammonia1 with various alkaline salts4 ,it differs somewhat in quality1 and is sold by analysis at a price dependent on the ammonia it contains4 ,i4 ,,ii4 ,water #ad4di #be4ci ,sulphate of ammonia #fb4ee #dg4gi ,muriate of ammonia #ae4c 444 ,sulphate of soda 444 #i4ab ,sulphate of magnesia 444 #ah4ch ,chloride of potassium #d4ge #b4id ,chloride of sodium #ag4ce #j4ce ------ ------ #ajj4jj #ajj4jj ,ammonia #af4ej #aa4bh ,the quality of sulphate of ammonia may generally be judged of from its dry and uniformly crystalline appearance1 and it may be tested by heating a small quantity on a shovel over a clear fire1 when it ought to volatilize completely1 or leave only a trifling residue4 ,some care1 however1 is necessary in applying this test1 as in the hands of inexperienced persons it is sometimes fallacious4 ,the salts of ammonia may be applied in the same way as guano2 but they are most advantageously employed as a top-dressing1 and principally to grass lands4 ,in this way very remarkable effects are produced1 and within a week after the application1 the difference between the dressed and undressed portions of a field is already conspicuous4 ,experience has shewn that success is best insured when the salt is applied during or immediately before rain1 so that it may be at once incorporated with the soil2 as when used in dry weather little or no benefit is derived from it4 ,it seems also to exert a peculiarly beneficial effect upon clover2 and hence it ought to be employed only on clover-hay1 as where ryegrass or other grasses form the whole of the crop we have better manures4 ,ammoniacal ,liquor of the ,gas-,works1 and of the ,animal ,charcoal ,manufacturers4--,both of these are excellent forms in which to apply ammonia1 when they can be obtained4 ,the ammoniacal liquor of the gas-works is very variable in quality1 but contains generally from #d to #h ounces of dry ammonia per gallon1 which corresponds in round numbers to from #a to #b lb4 of sulphate of ammonia4 ,it is best applied with the watering-cart1 but must be diluted before use with three or four times its bulk of water1 as if concentrated it burns up the grass1 and it is also advisable to use it during wet weather4 ,the ammoniacal liquor of the ivory-black works contains about #ab per cent of ammonia1 or about four or five times as much as gas liquor4 ,it has been used in some parts of ,england1 made into a compost1 and applied to the turnip and other crops1 and1 it is said1 with good effect4 ,bone oil1 which distils over along with it1 has also been used in the form of a compost2 it contains a large quantity of ammonia and of nitrogen in other forms of combination2 the total quantity of nitrogen it contains being #i4jd per cent1 which is equivalent to #aj4ih of ammonia4 ,only part of this nitrogen is actually in the state of ammonia2 and some circumstances connected with the chemical relations of the other nitrogenous compounds in this substance render it probable that they may pass very slowly into ammonia1 and may therefore be of inferior value2 but the substance deserves a trial1 as it is very cheap4 ,it must be carefully composted with peat1 and turned over several times before being used4 ,nitrates of ,potash and ,soda4--,nitrate of potash has long been used as a manure1 but its high price has prevented its general application1 and its place has now been almost entirely taken by nitrate of soda1 which is much cheaper and contains weight for weight a larger quantity of nitrogen4 ,both these salts are employed as sources of nitrogen2 but nitrate of potash owes also a certain proportion of its value to the potash it contains4 ,nitrate of soda1 on the other hand1 must be considered to owe its entire value to its nitric acid1 as soda is of little value to the plant2 and1 moreover1 can be obtained in common salt at a price so low1 as to make it a matter of no moment in the valuation of the nitrate4 ,in its ordinary state1 as imported from ,peru1 nitrate of soda contains from #e to #aj per cent of impurities1 and it bears a price proportionate to the quantity of the pure salt present in it4 ,when of good quality it contains about #ae per cent of nitrogen1 equivalent to #ah of ammonia1 and is1 therefore1 richer in that constituent of plants than ,peruvian guano4 ,it is essentially a rapidly acting manure1 and produces a marked effect within a very few days after its application2 but owing to the fact that nitric acid cannot be absorbed and retained by the soil in the same manner as ammonia1 it is liable to be lost unless it can be at once assimilated by the plant4 ,for this reason it acts best when applied in small quantity as a top-dressing to grass-land1 and to young corn4 ,a large application has no advantages1 and there can be no doubt that the best effect would be produced by several very small quantities1 applied at intervals4 ,in one experiment1 ,mr4 ,pusey found #db lb4 per acre to increase the produce of barley by #g bushels1 and very favourable results have been obtained by other experimenters4 ,the beneficial effects of nitrate of soda appear to be almost entirely confined to the grasses and cereals4 ,at least experience here has shewn that it produces little or no effect on clover2 and one farmer has stated1 that having recently adopted the practice of sowing clover with a very small proportion of ryegrass only1 he has been led to abandon the use of nitrate of soda1 which he formerly employed abundantly1 when ryegrass formed a principal part of his crop4 ,the action of nitrate of soda is very remarkable1 not only in this respect1 but also because a given quantity of nitrogen in it appears to produce a greater effect than the same quantity in sulphate of ammonia or guano4 ,at the same time this statement must be taken as very general1 definite experiments being still too few to admit of its being stated as an absolute fact4 ,the probability is1 that the same quantity of nitrogen1 in the form either of ammonia or nitrate of soda1 will produce the same effect1 although the conditions necessary for its successful action may not be the same with the two manures4 ,it is alleged that nitrate of soda is advantageously conjoined with common salt1 which is said to check its tendency to make the grain crops run to straw1 and to prevent their lodging1 as they are apt to do1 when it is employed alone4 ,but considerable difference of opinion exists in this point1 many farmers believing that salt produces no effect4 ,when employed for hay1 especially when mixed with clover1 it is advisable to use it along with an equal quantity of sulphate of ammonia1 which gives a better result than either separately4 ,salts of ,potash and ,soda4--,the substances just mentioned must be considered to owe their chief manurial value to nitric acid2 but other salts have been used as manures in which the effect is undoubtedly due to the alkalies themselves4 ,with the exception of common salt1 most of the alkaline salts have only been used to a limited extent2 and it is remarkable that1 so far as our present experience goes1 there is no class of substances from which more uncertain results are obtained4 ,muriate and ,sulphate of ,potash have both been used1 and the former has in some cases1 and in particular seasons1 produced a very remarkable effect in the potato2 but in other instances it has proved quite useless4 ,the cause of this difference has not been ascertained4 ,sulphate of soda has also been used to some extent1 but apparently without much benefit2 and there is no reason to expect that it should act better than common salt1 which can be obtained at a much lower price4 ,chloride of ,sodium1 or ,common ,salt1 has at different times been employed as a manure1 but its effects are so variable and uncertain1 that its use1 in place of increasing1 has of late years rather diminished1 it having frequently been found that on soils in all respects similar1 or even on the same soil1 in different years1 it sometimes proves advantageous1 at others positively injurious4 ,its use as an addition to nitrate of soda has been already alluded to1 and it is said that it produces the same effect when mixed with guano and salts of ammonia4 ,the accuracy of this statement is doubted by many persons1 and the explanation which has been given of the cause of its action is more than dubious4 ,it is supposed to enable the plant to absorb more silica from the soil2 but this is a speculative explanation of its action1 and has not been supported by definite experiment4 ,although little effect has been observed from salt1 it deserves a more accurate investigation1 as not withstanding the extent to which it has been employed1 we are singularly deficient in definite experiments with it4 ,carbonates of ,potash and ,soda have only been tried experimentally1 and that to a small extent1 nor is it likely that they will ever come into use1 owing to their high price4 ,the remarks we have made in the section on the ashes of plants regarding the subordinate value of soda1 will enable the reader to see that greater effects are to be anticipated from the former than from the latter of these salts4 ,they may1 however1 exert a chemical action on the soil1 altogether independent of their absorption by the plant1 but its nature and amount are still to determine4 ,silicates of ,potash and ,soda have been employed with the view of supplying silica to the plant1 but the results have been far from satisfactory4 ,this may perhaps have been due to the doubtful nature of the commercial article1 but now that silicate of soda can be obtained of good quality1 it is desirable that the experiments should be repeated4 ,it is said to have produced good effects on the potato4 ,sulphate of ,magnesia can be obtained at a low cost1 and has been used as a manure in some instances with very marked success4 ,it has been chiefly applied as a top-dressing to clover hay1 but it seems probable that it might prove a useful application to the cereals1 the ash of which is peculiarly rich in magnesia4 ,many other saline substances have been tried as manures2 but in most instances on too limited a scale to permit any definite conclusions as to their value4 ,the experiments have also been too frequently performed without the precautions necessary to exclude fallacy1 so that the results already arrived at must not be accepted as established facts1 but rather as indications of the direction in which further investigation would be valuable4 ,there is little doubt that many of these substances might be usefully employed1 if the conditions necessary for their successful application were eliminated2 and no subject is at present more deserving of elucidation by careful and well-devised field experiments4 ,phosphate of ,lime4--,the use of bones in their natural state as a manure has been already adverted to1 and it was stated1 that though their value depended mainly on the phosphates1 the animal matters and other substances contained in them were not without effect4 ,the action of phosphates is greatly promoted by solution in sulphuric acid1 and the application of the acid has brought into use many varieties of phosphates of purely mineral origin1 or which have been deprived of their organic matters by artificial processes4 ,of these1 the spent animal charcoal of the sugar-refiners1 usually containing about #gj per cent of phosphates1 and ,south ,american bone ash1 are the most important4 ,the latter is now imported in very large quantity1 and has the composition shewn in the following analyses3-- ,i4 ,,ii4 ,,iii4 ,water #f4aj #f4bh #c4jc ,charcoal #e4je #b4ai #b4jb ,phosphates #gi4bj #ga4aj #hh4ee ,carbonate of lime #d4je #c4ee #e4fj ,alkaline salts #j4ae traces 444 ,sand #e4de #af4ij #j4hj ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj ,bone ash has hitherto been almost entirely consumed as a raw material for the manufacture of superphosphates2 but as it is sold at from ,l#d3 #ajs4 to ,l#e3 #ajs4 per ton when containing #gj per cent of phosphates1 it is1 in reality1 a very cheap source of these substances1 and merits the attention of the farmer as an application in its ordinary state4 ,of strictly mineral phosphates1 a considerable variety is now in use1 but they are employed exclusively in the manufacture of superphosphates1 as in their natural state they are so hard and insoluble1 that the plant is incapable of availing itself of them4 ,coprolites4--,this name was originally applied by ,dr4 ,buckland to substances found in many geological strata1 and which he believed to be the dung of fossil animals4 ,it has since been given to phosphatic concretions found chiefly in the greensand in ,suffolk and ,cambridgeshire1 which are certainly not the same as those described by ,dr4 ,buckland1 but consist of fragments of bones1 ammonites1 and other fossils4 ,coprolites are now collected in very large quantities1 and about #dc1jjj tons are annually employed4 ,they are extremely hard1 and require powerful machinery to reduce them to powder1 and hence their price is considerable1 being about ,l#b3 #ajs4 per ton4 ,their composition varies somewhat according to the care taken in selecting them1 and the locality from which they have been obtained4 ,a general idea of their composition may be derived from the subjoined analyses3-- ,water #a4ie #a4ij ,organic matter #b4ei #f4he ,phosphate of lime #ee4ba #fa4ae ,phosphate of iron #c4hd ,carbonate of lime #bf4gj #af4bj ,sulphate of lime #a4ig ,alkaline salts #a4he #c4ba ,sand #e4hi #aa4fe ------ ------ #ajj4jj #ajj4jj ,within the last two or three years1 coprolites have been found in great abundance in ,france1 but they are of inferior quality1 and rarely contain more than #dj per cent of phosphates4 ,apatite1 or mineral phosphate of lime1 is found in large deposits in different places4 ,it is particularly abundant in ,spain1 and occurs also in ,america and ,norway4 ,from the latter country it has been imported to some extent2 and during the last year considerable quantities have been brought from ,spain1 and the importations will undoubtedly increase very largely as the means of transport improve in that country4 ,spanish apatite contains-- ,water #j4hj ,phosphate of lime #ic4cj ,carbonate of lime #j4ej ,chlorine1 etc4 traces ,sand #d4gj ----- #ii4cj ,several other varieties of mineral phosphates have been imported under the name of guano4 ,the most important is ,sombrero ,island guano1 which is found on a small island in the ,gulf of ,mexico1 where it occurs in a layer said to be forty feet thick4 ,it contains-- ,water #h4if ,phosphate of lime #cg4ga ,phosphates of alumina and iron #dd4ba ,phosphate of magnesia #d4bj ,sulphate of lime #j4hf ,carbonate of lime #c4cf ,sand #j4gj ------ #ajj4jj ,a somewhat similar substance1 but in hard crusts1 has been imported1 under the names of ,maracaybo guano1 ,pyroguanite1 etc41 which contains-- ,water #a4jc ,organic matter #f4gh ,phosphates #ge4fi ,alkaline salts #d4ia ,sand #aa4fd ------ #ajj4jj ,phosphoric acid in the alkaline #j4gh salts #a4fh phosphate of lime ,these substances are all excellent sources of phosphates1 but they are so hard that the plants cannot extract phosphoric acid from them1 and they are only useful when made soluble by chemical processes4 ,superphosphate2 ,dissolved ,bones4--,these names were at first applied to bones which had been treated with sulphuric acid2 but superphosphates are now rarely made from bones alone1 but bone ash and some of the mineral phosphates just described are employed1 either along with them1 or very frequently alone4 ,the manufacture of superphosphates depends on the existence of two different compounds of phosphoric acid and lime1 one of which contains three times as much lime as the other4 ,that which contains the larger quantity of lime is found in the bones and all other natural phosphates1 and is quite insoluble in water2 but when two-thirds of its lime are removed1 it is converted into the other compound1 which is exceedingly soluble4 ,this change is effected by the use of sulphuric acid1 which combines with two-thirds of the lime of the ordinary insoluble phosphate of lime1 and converts it into the biphosphate of lime1 which is soluble4 ,when1 therefore1 we add to #ajj lbs4 of common phosphate of lime the necessary quantity of sulphuric acid1 it yields #fd lbs4 of biphosphate1 containing the whole of the phosphoric acid1 which is the valuable constituent1 the diminution in weight being due to the removal of the valueless lime4 ,hence it follows1 also1 that as the lime so removed is converted into sulphate1 there must1 for every #ajj lbs4 of phosphate of lime converted into biphosphate1 be produced #hg lbs4 of dry sulphate of lime1 or #aaj of the ordinary sulphate called gypsum4 ,this is the minimum quantity which can be present1 but in actual practice it is liable to be greatly exceeded1 more especially where coprolites are used1 owing to the large amount of carbonate of lime they contain1 which is also converted into sulphate by the action of the acid1 so that it is far from uncommon to find the gypsum twice as great as it would be if materials free from carbonates could be obtained4 ,by employing a sufficiency of sulphuric acid1 the whole quantity of phosphoric acid in the bones may be thus brought into a soluble state1 but in actual practice it is found preferable to leave part of it in the insoluble condition2 as where it is entirely soluble1 its effect is too great during the early part of the season1 and deficient at its end4 ,in order to dissolve bones1 bone ash1 or mineral phosphates1 they are mixed with from a third to half their weight of sulphuric acid1 of specific gravity #a4gj or #adj deg4 ,twaddell4 ,when mineral phosphates1 and particularly coprolites1 are used1 the quantity of sulphuric acid must be increased so as to compensate for the loss of that which is consumed in decomposing the carbonate of lime they contain4 ,when operating on the small scale1 the materials are put into a vessel of wood1 stone1 or lead 7iron is to be avoided1 as it is rapidly corroded by the acid71 and mixed with from a sixth to a fourth of their weight of water1 which may with advantage be used hot4 ,the sulphuric acid is then added1 and mixed as uniformly as possible with the bones4 ,considerable effervescence takes place1 and the mass becomes extremely hot4 ,at the end of two or three days it is turned over with the spade1 and after standing for some days longer1 generally becomes pretty dry4 ,should it still be too moist to be sown1 it must be again turned over1 and mixed with some dry substance to absorb the moisture4 ,for this purpose everything containing lime or its carbonate must be carefully avoided1 as they bring back the phosphates into the insoluble state1 and undo what the sulphuric acid has done4 ,peat1 saw-dust1 sand1 decaying leaves1 or similar substances1 will answer the purpose1 and they should all be made thoroughly dry before being used4 ,an excellent plan is to sift the bones before dissolving1 to apply the acid to the coarser part1 and afterwards to mix in the fine dust which has passed through the sieve1 to dry up the mass2 or a small quantity of bone ash1 of good quality1 or ,peruvian guano1 may be used4 ,on the large scale1 mechanical arrangements are employed for mixing the materials1 so as to economise labour1 and mineral phosphates1 such as apatite1 can then be used with advantage4 ,in such cases1 blood1 sulphate of ammonia1 soot1 and other refuse matters1 are occasionally used to supply the requisite quantity of nitrogenous substances1 but large quantities are also made from bone ash1 etc41 without these additions4 ,the composition of superphosphates must necessarily vary to a great extent1 and depends not only on the materials1 but on the proportion of acid used for solution4 ,the following analysis illustrates the composition of good samples made from different substances-- ---------------------------------------- ------------------------------- ,bones alone4 ,bone-,ash4 ---------------------------------------- ------------------------------- ,water1 #g4gd 444 #g4gi #e4cc 444 #aj4dj ,organic matters and ammoniacal salts1 #ag4hc 444 #ba4fi #f4id 444 #d4ib ,biphosphate of lime #ac4ah 444 #i4hg #ba4ce 444 #bc4ji ,equivalent to soluble phosphates1 7#bj4eg74447ae4ci7 7#cc4cc74447cf4jb7 ,insoluble phosphates #aj4ca 444 #ba4ag #e4ib 444 #f4jh ,sulphate of lime1 #df4jj 444 #ce4cj #ef4af 444 #dg4gh ,alkaline salts1 #a4df 444 #j4id trace4 ,sand1 #c4dh 444 #c4jj #d4bc 444 #d4cj ------------------------------------ #ajj4jj 444#ajj4jj #ajj4jj 444#ajj4jj ,ammonia1 #b4aa 444 #c4ja #j4bc 444 #j4ca ---------------------------------------- ------------------------------- ---------------------------------------- --------------------------------- ,mixtures ,chiefly ,coprolites4containing ,salts of ,ammonia1 etc4 ---------------------------------------- --------------------------------- ,water1 #e4ij 444 #aj4ag #g4jg 444 #ae4hb ,organic matters and ammoniacal salts1 #e4aj 444 #d4ac #i4hg 444 #ac4if ,biphosphate of lime #ab4bd 444 #ac4ge #ag4fc 444 #ab4fg ,equivalent to soluble phosphates1 7#ai4aj74447ba4dc7 7#bg4ej74447ai4gg7 ,insoluble phosphates #af4ij 444 #j4ag #ab4fj 444 #h4dj ,sulphate of lime1 #eb4ci 444 #fb4fb #di4gg 444 #de4ad ,alkaline salts1 #b4dg 444 #j4if #j4jf 444 #a4jg ,sand1 #f4jj 444 #h4bj #c4jj 444 #b4id -------------------------------------- #ajj4jj 444#ajj4jj #ajj4jj 444#ajj4jj ,ammonia1 #j4aa 444 #j4eg #a4bh 444 #a4ee ---------------------------------------- --------------------------------- ,superphosphates made from bones alone are generally distinguished by a large quantity of ammonia1 and a rather low per centage of biphosphate of lime4 ,this is owing to the difficulty experienced in making the acid react in a satisfactory manner on bones1 the phosphates being protected from its action by the large quantity of animal matter which1 when moistened1 swells up1 fills the pores1 and prevents the ready access of the acid to the interior of the fragments4 ,superphosphates from bone-ash1 on the other hand1 contain a mere trifle of ammonia1 and when well made a very large quantity of biphosphate of lime4 ,their quality differs very greatly1 and depends1 of course1 on that of the bone-ash employed1 which can rarely be obtained of quality sufficient to yield more than #cj or #ce per cent of soluble phosphates4 ,coprolites are seldom used alone for the manufacture of superphosphates1 but are generally mixed with bone-ash and bone dust4 ,mixtures containing salts of ammonia1 flesh1 blood1 etc41 are also largely manufactured1 and some are now produced containing as much as four or five per cent of ammonia1 and the consumption of such articles is largely increasing4 ,the analyses above given are all those of good superphosphates1 in which abundance of acid has been used so as to convert a large proportion of insoluble into soluble phosphates2 but there are many samples of very inferior quality to be met with in the market1 in which the proportion of acid has been reduced1 and the quantity of phosphates made soluble is consequently much lower than it ought to be4 ,the following analyses illustrate the composition of such manures1 which are all very inferior and generally worth much less than the price asked for them4 ,water #ba4fj #e4cg #g4ai ,organic matter and ammoniacal salts1 #aa4fb #ac4ia #h4hj ,biphosphate of lime #b4ih #b4jb #f4db ,equivalent to soluble phosphates 7#d4fe7 7#c4ae7 7#aj4jb7 ,insoluble phosphates #be4gj #ae4hj #ad4jc ,sulphate of lime #bc4ff #dg4eb #ea4ic ,alkaline salts #aj4gj #c4gc #c4dc ,sand #c4hj #aa4fe #h4bj ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj ,ammonia1 #a4cb #j4ei #j4cc ,the deliberate adulteration of superphosphate1 that is1 the addition to it of sand or similar worthless materials1 ,i believe to be but little practised4 ,the most common fraud consists in selling as pure dissolved bones1 articles made in part1 and sometimes almost entirely1 from coprolites4 ,occasionally refuse matters are used1 but less with the intention of actually diminishing the value of the manure as for the purpose of acting as driers4 ,it is said that sulphate of lime is sometimes employed for this purpose1 but this is rarely done1 because that substance is always a necessary constituent of superphosphate in very large quantities2 and as farmers look upon it with great suspicion1 all the efforts of the manufacturers are directed towards reducing its quantity as much as possible4 ,it is very commonly supposed by farmers that the sulphate of lime found in so large quantity in all superphosphates1 and often amounting to as much as fifty per cent1 has been added to the materials in the process of manufacture1 but this is a mistake2 it is a necessary and inevitable product of the chemical action by which the phosphates are rendered soluble1 although its quantity depends on the materials from which the manure is made4 ,when pure bones are used its quantity is small1 and it does not greatly exceed twice that of the biphosphate of lime2 but in a manure made from coprolites1 or other substances containing a large proportion of carbonate of lime1 which must in the process of manufacture be converted into sulphate1 it may be four or five times as much4 ,although there is no manure which varies more in quality1 or requires greater vigilance on the part of the purchaser1 in order to obtain a good article1 there is no doubt that superphosphates1 owing to the process of manufacture being better understood1 and to increased competition1 have considerably improved in quality4 ,six or eight years since a manure containing thirty per cent of phosphates1 of which twelve or fifteen had been converted into biphosphate1 was considered a fair sample1 but now the proportion rendered soluble is greatly increased2 and where bone ash alone is employed1 as much as thirty and even forty per cent of soluble phosphates is occasionally found4 ,this1 of course1 is an exceptional case1 and great attention and care in the selection of materials are necessary to obtain so large a proportion4 ,the analyses already given will shew the farmer what he has to expect in good superphosphates1 but it is very necessary that he should take care to obtain from the manufacturer a manure equal to the guarantee2 and he ought to bear in mind that1 owing to the difficulty of getting materials of constant composition1 variations often take place to a considerable extent in manures which are supposed to be made in exactly the same manner4 ,phospho-,peruvian ,guano4--,under this name a kind of superphosphate1 which is understood to be made by dissolving a native rock guano1 has recently attracted considerable attention1 and is used to a large extent4 ,its composition is-- ,water #i4ed ,organic matter #ba4ch ,biphosphate of lime1 equivalent to #be4bb soluble phosphates #af4ha ,insoluble phosphates #aj4hh ,sulphate of lime #cg4ba ,alkaline salts1 containing #a4cb of phosphoric acid1 and equivalent to #b4hf soluble phosphates #b4bb ,sand #a4ha ------ #ajj4jj ,ammonia1 #c4ej ,it is chiefly distinguished by the large proportion of valuable ingredients it contains1 and the care taken to secure uniformity of composition4 ,a variety of substances are sold under the name of nitrophosphate1 potato manure1 cereal manure1 etc4 etc41 which are all superphosphates1 differing only in the proportion of their ingredients1 and in the addition of small quantities of alkaline salts1 sulphate of magnesia1 and other substances1 but they present little difference from ordinary superphosphates in their effects4 ,the use of superphosphate has greatly extended of late years1 and its consumption has increased in a greatly more rapid ratio than that of guano or any other manure4 ,ten or twelve years since it was comparatively little known1 but it has now come to be used in many cases in which ,peruvian guano was formerly employed4 ,it produces a better effect than that manure on light soils1 although in general a mixture of the two answers better than either separately4 ,when ,peruvian guano is to be applied along with it1 the farmer will naturally select a superphosphate made from bone ash1 and containing the largest obtainable quantity of soluble phosphates2 but when it is to be used alone1 it is advisable to take one made from bones1 or at all events one containing a considerable quantity of nitrogenous matter or ammonia4 ,the kind to be selected must1 however1 be greatly dependent on the particular soil1 and the situation in which it is to be used4 ,lime4--,lime is by far the most important of the mineral manures1 and an almost indispensable agent of agricultural improvement4 ,it has been used as chalk1 marl1 shell and coral sand1 ground limestone1 and as quick and slaked lime1 and its action varies according as it is applied in any of its natural forms1 or after being burnt4 ,in all of its native forms the lime is combined with carbonic acid in the proportion of fifty-six parts of lime to forty-four of carbonic acid1 and the carbonate is generally mixed with variable quantities of earthy ingredients1 which in some instances are important additions to it1 and affect its utility as a manure4 ,chalk is a very pure form of carbonate of lime1 and where it abounds has been largely employed as an application on the soil4 ,it is dug out of pits and exposed to the action of the winter's frost1 by which it is thoroughly disintegrated1 and in spring it is applied in quantities1 which1 in many instances1 are only limited by the question of cost4 ,marl is a name given to a mixture of finely-divided carbonate of lime1 with variable proportions of clay and siliceous matters1 which is found at the bottom of valleys and in hollow places in beds often of considerable extent and thickness1 where it is deposited from the waters of lakes holding lime in solution1 fed by streams passing over limestone1 or rocks rich in lime4 ,the composition of marls differs greatly in different districts1 and they have been divided into true marls1 and clay marls1 according as the carbonate of lime or clay is the preponderating ingredient4 ,the following table illustrates the composition of different varieties3-- ---------------------------------------- ---------------------------------- ,barbadoes4 ,luneburg4 ,ayrshire4 ,wesermarsh4 ---------------------------------------- ---------------------------------- ,carbonate of lime #ic4b #he4d #h4d #h4b ,carbonate of magnesia 444 #a4c 444 #c4j ,sulphate of lime 444 #j4a 444 #j4e ,phosphate of lime #j4a #b4c 444 #a4b ,alumina and oxide of iron #a4f #d4f #b4b #g4b ,alkaline salts 444 #j4a 444 #a4j ,silica and clay #d4f #e4f #hd4i #gh4i ,organic matter #j4e #j4f #b4h 444 ,water 444 444 #a4d 444 ---------------------------------------- ---------------------------------- #ajj4jj #ajj4jj #ii4g #ajj4jj ---------------------------------------- ---------------------------------- ,the true marls1 that is those in which carbonate of lime abounds1 are greatly preferable to clay marls1 the latter1 indeed1 operate chiefly mechanically1 by altering the texture of the soil--the lime they contain being frequently too small to exercise much appreciable effect4 ,shell and coral sands consist chiefly of fragments of shells and coral disintegrated by the action of the waves1 and mixed with more or less siliceous sand1 and containing small quantities of phosphate of lime4 ,they occur to a considerable extent both on our own coasts and those of ,france1 and have been used with good effect on some descriptions of soil4 ,the general composition of limestones has been already adverted to1 when treating of the origin of soils1 and a distinction drawn between the common limestones and dolomite or magnesium limestone4 ,few limestones can be considered as even approaching to purity1 and they almost all contain a small quantity of carbonate of magnesia as well as earthy matters1 and occasionally a little phosphate of lime4 ,in good specimens the quantities of these substances are generally small1 and they usually contain about half their weight of lime4 ,when limestone is burnt in the kiln1 the change which ensues consists in the expulsion of the carbonic acid1 and the consequent conversion of the lime into the uncombined or quick state4 ,if water be thrown upon it when in this condition1 it becomes hot1 swells up1 and falls to a fine soft powder1 and has then entered into combination with water4 ,if it be exposed to the air1 the same action takes place1 although1 of course1 more slowly2 and if it be left for a sufficient time1 it at length absorbs carbonic acid1 and reverts to its original form of carbonate of lime1 although now in a state of very fine division4 ,while lime may be applied in the state of carbonate1 either as chalk1 marl1 or pounded limestone1 and with a certain amount of advantage1 much greater effects are obtained from the use of lime itself in the quick or slaked state4 ,these advantages are dependent partly on the mechanical effect of the burning and slaking1 which enable us to reduce the lime to a much more minute state of division1 and consequently to incorporate it more uniformly and thoroughly with the soil1 and partly on the more powerful chemical action which it exists when in the quick or caustic state4 ,other minor advantages are also secured1 such as the production of a certain quantity of sulphate of lime1 produced by the oxidation of the sulphur of the coal used in burning1 etc41 which1 though comparatively trifling1 may1 under particular circumstances and in some soils1 be of considerable importance4 ,the action of lime is of a complicated character4 ,where the soil is deficient in lime1 it must necessarily act by supplying that substance to the plants growing in it4 ,but this is manifestly a very subordinate part of its action1--#ast1 ,because no soil exists which does not contain lime in sufficient quantity to supply that element to the plants4 #b;d1 ,because its effects are not restricted to those soils in which it exists naturally in small quantity2 and1 #c;d1 ,because it is found that a small application1 such as would suffice for the wants of the crops1 is not sufficient to produce its best effects4 ,it is a familiar fact that the quantity of lime applied to the soil for agricultural purposes is very large1 as much as ten1 and even twenty tons per acre having been used1 while the smallest application is exceedingly large when compared with the mere requirements of the crops4 ,of late years the very large applications once in use have become less common1 as it has been found preferable to employ smaller doses more frequently repeated4 ,the quantity used depends1 however1 to a great extent1 on the nature and condition of the soil1 heavy clays1 especially if undrained1 and soils of a peaty nature1 requiring a large application2 while on well drained and light soils a smaller quantity suffices4 ,thin soils also require only a small application4 ,the geological origin of the soil is also not without its influence1 and its beneficial effect is peculiarly seen on granite1 porphyry1 and gneiss soils1 both because these are naturally deficient in lime1 and because the decompositions by which their valuable constituents are liberated take place with extreme slowness4 ,the greater part of the action of lime is unquestionably dependent on its exerting a chemical decomposition on the soil2 and it acts equally on both the great divisions of its constituents1 the inorganic and the organic4 ,on the former1 it operates by decomposing the silicates1 which form the main part of the soil1 and the alkalies they contain being thus set free1 a larger supply becomes available to the plant4 ,on the organic constituents its effects are principally expended in promoting the decomposition which converts their nitrogen into ammonia2 and thus a supply of food1 which might remain for a long period locked up1 is set free in a state in which the plant can at once absorb it4 ,but these chemical decompositions are attended by a corresponding change in the mechanical characters of the soil4 ,heavy clays are observed to become lighter and more open in their texture2 and those which are too rich in organic matter have it rapidly reduced in quantity1 and the excessive lightness which it occasions diminished4 ,the effects of an application of lime are not generally observed immediately1 but become apparent in the course of one or two years1 when it has had time to exert its chemical influence on the soil2 but from that time its effects are seen gradually to diminish and finally to cease entirely4 ,the period within which this occurs necessarily varies with the amount of the application and the nature of the soil1 but it may be said generally that lime will last from ten to fifteen years4 ,the cessation of its effects is due to several circumstances1 partly of course to the absorption of lime by the plants1 partly to its being washed out of the soil by the rains1 and partly to its tendency to sink to a lower level1 a tendency which most practical men have had opportunities of observing4 ,in the latter case1 deep-ploughing often produces a marked effect1 and sometimes makes it possible to postpone for a year or two the reapplication of lime4 ,all these circumstances have their influence in bringing its action to an end1 but the most important is1 that after a time it has exhausted its decomposing effect on the soil1 having destroyed all the organic matter1 or liberated all the insoluble mineral substances which the quantity added is competent to do1 and so the soil passes back to its old state4 ,it does even more1 for unless active measures are taken to sustain it by other means1 it is found that the fertility of the soil is apt to become less than it was before the use of lime4 ,and that it should be so is manifest1 if we consider that the lime added has liberated a quantity of inorganic matter1 which1 in the natural state of the soil1 would have become slowly available to the plant1 and that it must have acted chiefly in those very portions which1 from having already undergone a partial decomposition1 were ready to pass into a state fitted for absorption1 and thus as it were must have anticipated the supplies of future years4 ,this effect has been frequently observed by farmers1 and is indeed so common1 that it has passed into a proverbial saying1 that lime enriches the fathers and impoverishes the sons4 ,but this is true only when the soil is stinted of other manures1 for when it is well manured the exhausting effect of lime is not observed2 and it must be laid down as a practical rule1 that its use necessitates a liberal treatment of the soil in all other respects4 ,but when lime has been once employed it becomes almost necessary to resort to it again2 and generally so soon as its effects are exhausted a new quantity is applied1 not so large as that which is used when the soil is first limed1 but still considerable4 ,when this is done very frequently1 however1 bad effects ensue2 the soil gets into a particular state1 in which it is so open that the grain crops become uncertain1 and such land is said1 in practical language1 to be overlimed4 ,the explanation of this state of matters commonly assumed by those unacquainted with chemistry is1 that the land has become too full of lime2 but a moment's consideration of the very small fraction of the soil which even the largest application of lime forms1 will serve to shew that this cannot be the cause4 ,ten tons of lime per acre amounts to only one per cent of the soil1 and as a considerable part of the lime is carried off by drainage in the course of years1 it is obvious that even very large and frequently repeated doses are not likely to produce any great accumulation of that substance4 ,in point of fact1 analyses of overlimed soils have proved that the lime does not exceed the ordinary quantity found in fertile land4 ,the explanation of the phenomenon is probably to be found in the rapid decomposition of organic matter by the lime1 and its escape as carbonic acid1 by which the soil is left in that curious porous condition so well known in practice4 ,the cure for overliming is found to be the employment of such means as consolidate the soil1 such as eating off with sheep1 rolling1 or laying down to permanent pasture4 ,the immediate effect of lime on the vegetation of the land to which it is applied is very striking4 ,it immediately destroys all sorts of moss1 makes a tender herbage spring up1 and eradicates a number of weeds4 ,it improves the quantity and quality of most crops1 and causes them to arrive more rapidly at maturity4 ,the extent to which it produces these effects is dependent on the form in which it is applied4 ,when the lime is used hot1 that is1 immediately after it has been slaked1 they are produced most rapidly and effectually2 but if it has been so long exposed to the air as to absorb much of the carbonic acid it lost in burning1 and has got into what is commonly called the mild state1 it operates more slowly2 and when it is applied as chalk1 marl1 or pounded limestone1 its action is still more tardy4 ,various circumstances1 which must depend upon very different considerations1 must necessarily influence the farmer in the selection of one or other of these different forms of lime2 but on the whole1 it will be found that the greatest advantages are on the side of the well-burned and freshly slaked lime4 ,the consideration of all the minutiae to be attended to1 however1 would carry us far beyond the limits of this work1 and trench to some extent on the subject of practical agriculture4 ,various kinds of refuse matters containing lime have been used in agriculture1 but they are generally inferior to good lime1 and not generally more economical4 ,the most important of these is gas lime1 or lime which has been used for purifying coal gas4 ,in going through this process it absorbs carbonic acid from the gas1 and consequently passes back1 more or less1 completely into the form of carbonate of lime4 ,but it also takes up sulphur1 which remains in it in the form of sulphuret of calcium4 ,it is well known that all sulphurets are prejudicial to vegetable life1 and hence1 when fresh gas lime is used1 its effects are often injurious rather than beneficial4 ,but if it be exposed for some time to the air1 oxygen is absorbed1 the sulphur is converted into sulphuric acid1 gypsum is produced to the extent of some per cent1 and the lime then becomes innocuous4 ,when composted with dry soil1 the admission of air into the interior of the lime is facilitated1 and this change takes place with greater rapidity4 ,the waste lime from bleach-works1 tanneries1 and other manufactories1 is occasionally used by farmers2 but unless obtained at a nominal price1 it cannot compete with good quick lime1 owing to the large amount of water it contains1 and the consequent increase in the cost of carriage4 ,sulphate of ,lime or ,gypsum4--,gypsum has been extensively used as a manure1 and is found to exert a very remarkable influence upon clover1 and leguminous crops generally4 ,it is employed in quantities varying from two cwt4 per acre up to a very large quantity1 and almost invariably with good results1 in some instances even with the production of double crops4 ,much speculation has taken place as to the cause of this action which is so specific in its character1 and from ,sir ,humphrey ,davy down to the present time1 many chemists and agriculturists have considered the matter4 ,sir ,humphrey ,davy attributed its action to its supplying sulphur to those plants which1 according to him1 contain an unusually large quantity of that element4 ,that opinion has been since entertained by others1 but it can scarcely be considered as well founded1 for the more accurate experiments recently made do not point to any conspicuous differences between the quantities of sulphur contained in these and other plants4 ,it is1 moreover1 to gypsum alone that these effects are due1 and if it were merely as a source of sulphur that it was employed1 there are other salts which could be equally1 perhaps more advantageously1 used2 such1 for instance1 as sulphate of soda4 ,others have attributed its action to its power of fixing ammonia1 but this explanation is certainly untenable1 for the soil itself possesses this property very powerfully1 and it is inconceivable that the addition of a few hundred weights of gypsum should have any effect in promoting this action4 ,the experiments which have been made with gypsum leave no doubt as to its effect1 more especially on leguminous plants1 but they do not afford an explanation of its mode of action1 for which further inquiries1 directed especially to that object1 are required4 ,the application of gypsum to the soil appears to have diminished of late years1 and this is probably due to the large consumption of superphosphates1 and other manufactured manures1 which contain it in abundance4 ,in an ordinary application of these substances1 there are contained from one to two hundredweight of gypsum2 and it is not likely that when they have been extensively used1 much benefit will be derived from a further application of it by itself4 ,,chapter ,,xii4 ,,the ,,valuation ,,of ,,manures4 ,the determination of the value of a manure is in many respects a commercial rather than a chemical question1 but as it must be founded on the analysis1 and presents some peculiarities dependent on the complicated nature of the substances to be valued1 it has fallen to some extent into the hands of the chemist4 ,the principle on which the value of any commercial sample is estimated is very simple4 ,it is only necessary to know the price of the pure article1 and that of the particular sample to be valued is obtained by making a deduction from this price proportionate to the per centage of impurities shewn by the analysis4 ,thus1 for example1 if pure sulphate of ammonia sells at ,l#af per ton1 a sample containing #aj per cent of impurities ought to be purchased for ,l#ad3 #hs41 and so on for any other quantity4 ,this system which answers perfectly with sulphate of ammonia1 nitrate of soda1 or any other substance whose value depends on one individual element1 is inapplicable in the case of complex manures1 such as guano and the like1 in which several factors combine to make up the value4 ,in such cases1 manures of very different composition may have the same value1 the deficiency in one particular element being counterbalanced by the excess of another4 ,hence it becomes necessary to obtain an estimate of the value of each factor1 from which that not only of one particular substance1 but of every possible mixture may be determined4 ,when we come to inquire minutely into this question1 it appears that the commercial value of any substance is not estimated solely by considerations of composition1 but is dependent to a great extent on questions of demand and supply1 and applicability to particular purposes4 ,thus coprolites containing from #ee to #fj per cent of phosphates sell at about ,l#b3 #abs4 per ton1 while bone-ash containing the same quantity of that ingredient brings about twice as much2 in other words1 phosphates are nearly twice as valuable in bone-ash as in coprolites1 and as a phosphatic guano their price is generally still higher2 and the reason for this is obvious1 in bones and guano the phosphates are in a high state of division1 in which they are easily attacked and disintegrated by the carbonic acid of the soil1 and rendered available to plants2 while in coprolites they are in a hard and compact form1 and are of little use unless they have previously undergone an expensive preparation4 ,in the same way1 if the market price of different kinds of guano be inquired into1 very great differences are found to exist in the rate at which phosphates are sold1 and this is attributable in part to the fact that the price at which any article is charged commercially1 is such as to cover the prime cost1 expense of freight1 and other charges1 and to leave a profit to the importer2 and partly1 also1 no doubt1 to the carelessness with which manures are often purchased1 and to the want of careful field experiments in which the effects produced by them are properly compared4 ,it will be readily understood that the state of division of any substance1 the readiness with which its constituents can be rendered available to the plants1 care of application1 and many other circumstances must influence its price2 but making due allowance for these1 differences are met with which appear to some extent to be merely the result of caprice4 ,it is easy to understand why bone-ash should sell at double the price of coprolites1 but no good reason can be shewn why the phosphates in one kind of guano should be sold at a much higher price than another1 and the difference would probably disappear if greater attention were paid to the results of field experiments4 ,however great and inexplicable these differences may be1 it is not the business of the valuator of a manure to discuss them4 ,on the contrary1 he is bound to accept them as the basis of his calculation1 and to endeavour to deduce from them a proper system of estimation for each substance4 ,strictly speaking1 each individual manure ought to be valued according to a plan special to itself1 and deduced from its own standard market price2 but it is obvious that this would lead to innumerable complications and defeat its own ends1 and hence an attempt has been made to contrive a general system suited to all manures1 and which1 though not absolutely correct1 is a sufficient approximation for all practical purposes1 and a tolerably accurate guide to the determination of their relative values4 ,the constituents of a manure which are of actual value are ammonia1 insoluble phosphates1 biphosphate of lime 7soluble phosphates71 sulphate of lime1 nitric acid 7as nitrate of soda71 potash1 soda1 and organic matter4 ,these substances differ greatly in value4 ,ammonia and phosphates1 soluble and insoluble1 are costly2 and by far the larger part of the value of all guanos1 and the common manufactured manures1 depends on them4 ,nitric acid and potash are also very valuable substances1 but as they are rarely found in manufactured manures1 and never in sufficient quantity to exert any material influence in their price1 it is not usual to take them into consideration except in particular cases4 ,the alkali which commonly exists in artificial manures is soda1 and when alkaline salts appear in any analysis1 they must be assumed to consist almost entirely of that substance generally in the form of common salt1 and be valued accordingly4 ,sulphate of lime and organic matter though abundant constituents of most manures1 add but little to their value1 and it is a moot point whether they ought to be taken into consideration1 although most persons allow a small value for them4 ,carbonate of lime1 sand1 or siliceous matter1 and water1 of course1 are altogether worthless4 ,in order to obtain the value of a manure containing several of these substances1 it is necessary to ascertain the average commercial price of each individually4 ,this is easily done when they are met with in commerce separately1 or at least mixed only with worthless substances1 but some of them are only found in complex mixtures1 and in these cases it is necessary to arrive at a result by an indirect process1 according to methods which will be immediately explained4 ,the question to be solved is the price actually paid for a ton of each substance in a pure state1 and we shall proceed to consider them in succession4 ,insoluble ,phosphates4--,these are purchased alone1 chiefly in the form of coprolites and bone-ash1 or the spent animal charcoal of the sugar refiners4 ,ground coprolites1 containing about #eh per cent of phosphates1 sell at ,l#b3 #abs4 per ton1 which is at the rate of ,l#d3 #hs4 for pure phosphates4 ,bone-ash varies considerably in price1 but of late samples containing #gj per cent of phosphates have sold as low as ,l#d3 #ajs4 per ton1 and consequently pure phosphates in this form are worth ,l#f3 #hs4 per ton4 ,although these are the only forms in which phosphates are purchased alone1 it is possible to determine the price at which they are sold in bones and phosphatic guanos1 by first deducting the value of the ammonia they contain1 and assuming the remainder to represent the price paid for the phosphates4 ,in this way we find the following values for insoluble phosphates3-- ,in ,coprolites ,l#d #aj #j ,bone-ash #f #h #j ,bones #g #e #j ,phosphatic guanos #aj #j #j ,it is to be observed that these are actual prices1 and they are liable to fluctuate with the state of the market1 although they are pretty fair averages4 ,it is important to notice how much they vary in the different forms2 the farmer who buys a phosphatic guano paying for phosphates a much higher price than he could have obtained those for in other substances--a difference which must be attributed to the high state of division in which they exist in the guano4 ,we do not here enter upon the question how far this difference in price is justified2 we are content with the fact that it exists1 and we are compelled to estimate the value of phosphates in a phosphatic guano at the price given above1 although in ,peruvian guano they are sold at a lower rate4 ,for all other manures1 of which bones and bone-ash form the basis1 ,l#g may be taken as a fair price1 and it is that usually adopted1 though ,l#h and ,l#aj have sometimes been assumed as the average4 ,ammonia is met with in commerce as muriate and sulphate of ammonia4 ,the former1 owing to its high price1 is practically excluded from use as a manure2 the latter sells at present at from ,l#ae to ,l#ae3 #ajs4 per ton1 and1 making allowance for the usual amount of impurity 7#e or #f per cent71 the actual ammonia is worth about ,l#fc per ton4 ,calculating from other substances it appears that ammonia is worth1 per ton1 in-- ,sulphate of ammonia ,l#fc #j #j ,bones #fa #j #j ,peruvian guano #eg #j #j the average being ,l#fj1 which is the price usually adopted4 ,sulphate of ,lime and ,alkaline ,salts 7consisting chiefly of soda7 are generally estimated at ,ll per ton2 and potash in those cases1 in which it is necessary to take it into account1 is usually valued at from ,l#bj to ,l#cj per ton1 the former being its value in kelp1 the form in which it can be most cheaply purchased4 ,nitrate of ,soda is usually sold at from ,l#ae to ,l#ae3 #ajs4 per ton1 and1 making allowance for impurities1 ,l#af may be taken as the value of the pure salt4 ,biphosphate of ,lime1 ,soluble ,phosphates4--,considerable difficulty is experienced in estimating the value of these substances1 because they are not met with in commerce alone1 or in any form except that of superphosphate1 and the prices at which they are sold in different samples of that manure differ excessively4 ,the only course by which any result can be obtained1 is to determine the average price of a good superphosphate1 and putting the values already ascertained on all the other constituents to reckon the difference between that sum and the market price as the value of soluble phosphates4 ,throwing out1 as inferior1 all samples containing less than #aj per cent of soluble phosphates1 and taking the good only1 ,i find that the average composition of the phosphates in the market during the present year has been-- ,water #aj4ga ,organic matter #i4cc ,biphosphate of lime equivalent to #ai4dc soluble phosphates #ab4de ,insoluble phosphates #ad4gh ,sulphate of lime #de4bd ,alkaline salts #b4aa ,sand #e4ch ------ #ajj4jj ,ammonia #a4ga ,it is more difficult to fix the average price of superphosphate1 as in many cases no information could be obtained on this point2 but among those analyzed were samples at all prices1 from ,l#g up to ,l#aj3 #ajs4 per ton1 so that on the whole1 ,l#h may be assumed as an average1 and in that case soluble phosphates are worth ,l#bg3 #ais4 per ton4 ,had the inferior samples been included1 the price would have been higher1 and in fact the rate at which soluble phosphates have been commonly estimated is ,l#cj per ton1 or ,l#df3 #afs4 for biphosphate of lime1 although sometimes the former have been reckoned as low as ,l#be1 with a corresponding rate for the latter4 ,it is important that biphosphate of lime and soluble phosphates should not be confounded with one another in valuing a manure1 the latter having one and a half times the value of the former4 ,as manures are liable to considerable fluctuations in price1 the value attached to each of their constituents ought to be varied with the state of the market2 but it is obviously impossible for the farmer to watch the changes in price with such minuteness as to enable him to do this1 and it is much more convenient1 as well as safer1 to adopt a fixed average1 which can be used with reasonable accuracy at all times4 ,the fact is1 that this system of valuation is only an approximation to the truth2 and if absolute accuracy were aimed at1 it would be necessary to vary the estimates1 not only at different times1 but at different localities at the same time1 and to some extent also according to the kind of manure4 ,the price of soluble phosphates more especially1 fluctuates to a great extent1 being practically fixed by each manufacturer according to the facilities which his position or command of raw material offer for producing them at a low rate4 ,we thus find that when made from bones alone1 the cost of that substance is not unfrequently as high as ,l#dj per ton1 and when bone-ash alone is used it is sometimes as low as ,l#bj4 ,such extreme differences1 of course1 cannot be taken into account in the system of valuation adopted1 where all that can be done is to take average values1 which1 when applied to average samples1 ought to bring out their value4 ,the data which have already been given regarding the price of the individual constituents of manures can be applied to the determination of the value of any mixture in two different ways by means of the subjoined table3-- ---------------------------------------- ------------------------ ,price per ,ton4 ,per cent per ,ton4 ---------------------------------------- ------------------------ ,ammonia ,l#fj #j #j ,l#j #ab #j ,insoluble phosphates #g #j #j #j #a #e ,do4 in phosphatic guanos #aj #j #j #j #b #j ,soluble phosphates #cj #j #j #j #f #j ,biphosphate of lime #df #af #j #j #i #d-a_/b ,alkaline salts #a #j #j #j #j #b-d_/aj ,sulphate of lime #a #j #j #j #j #b-d_/aj ,potash #bj #j #j #j #d #j ,nitrate of soda #af #j #j #j #c #b-a_/b ,organic matter #j #aj #j #j #j #a-a_/d ---------------------------------------- ------------------------ ,supposing it be desired to calculate the value of a manure by the first column1 it is obvious that if we suppose #ajj tons to be purchased1 the per centages of the different constituents shewn in the analysis will give the number of tons of each contained in #ajj tons of the mixture1 and1 selecting the analysis of the superphosphate given in a previous page1 we proceed in the calculation as follows3-- #ad4aa tons of organic matter at #ajs4 ,l#g #j #j #ad4hf soluble phosphates at ,l#cj #ddf #j #j #ae4ac insoluble phosphates at ,l#g #aje #j #j #ci4dc sulphate of lime at ,l#a #ci #j #j #c4hb alkaline salts at ,l#a #d #j #j #b4aj ammonia at ,l#fj #abf #j #j ---------- ,value of #ajj tons ,l#gbg #j #j or ,l#g 3 #es4 per ton4 ,according to the second column1 the numbers give the sum by which the per centages of each ingredient must be multiplied1 to give its value in a ton of manure1 and it is used for the same manure in the following manner3-- #ad4aa organic matter1 multiplied by #a-a_/d;d4 ,l#j #a #e #ad4hh soluble phosphates #fs4 #d #i #b #ae4ac insoluble phosphates #as4 #e;d4 #a #a #d #ci4dc sulphate of lime #b-d_/aj;d4 ,o #h #aj #c4hb alkaline salts #b-d_/aj;d4 ,o ,o #i #b4aj ammonia #abs4 #a #e #c -------- ,value per ton ,l#g #f #i ,the difference is due to the less minute calculation of fractional quantities in the latter case4 ,the calculation of the value of any other manure is effected in exactly the same manner1 taking care1 however1 to use the higher value for phosphates in the case of a phosphatic guano4 ,it will be obvious to every one who tries the two methods that the first greatly exceeds the second in convenience and simplicity in the calculations1 and it is that most commonly in use1 although some persons prefer the second4 ,although the data just given must always form the basis of the valuation of any manure1 there are a variety of other circumstances which must be taken into account1 and which give great scope for the judgment and experience of the valuator4 ,of these the most important is the proper admixture of the ingredients1 and the condition of the manure as regards dryness1 complete reduction to the pulverulent state1 and the like4 ,a certain allowance ought always to be made for careful manufacture2 and1 on the other hand1 where the manure is damp or ill reduced1 a small deduction 7the amount of which must be decided by the experience of the valuator7 ought to be made on account of the risk which the farmer runs of loss from unequal distribution1 and the extra cost of carriage of an unnecessary quantity of water4 ,it is also necessary to take into account the particular element required by the soil4 ,thus1 a farmer who finds his soil wants phosphates1 will look to the manure containing the largest quantity of that substance1 and possibly not requiring ammonia1 will not care to estimate at its full value any quantity of that substance which he may be compelled to take along with the former1 but will look only to the source from which he can obtain it most cheaply4 ,it may be well1 therefore1 to point out that ammonia is most cheaply purchased in ,peruvian guano2 insoluble phosphates in coprolites2 and soluble phosphates in superphosphates1 made from bone-ash alone4 ,in general1 however1 it will be found most advantageous to select manures in which the constituents are properly adjusted to one another1 so that neither ammonia1 soluble nor insoluble phosphates1 preponderate2 but1 of course1 it must frequently happen that it will prove more economical to buy the substances separately and to make the mixture1 than to take the manure in which they are ready mixed4 ,in judging of the value of any manure1 it is also important to make sure that the analysis which forms the basis of the calculation is that of a fair sample1 which correctly represents the bulk actually delivered to the purchaser1 and not one which has been made to do duty for an unlimited quantity of manure1 which is supposed to be all of equal quality1 as often happens in the hands of careless manufacturers1 and too great attention cannot be devoted to the selection of the sample1 which is very often done in an exceedingly slovenly manner4 ,,chapter ,,xiii4 ,,the ,,rotation ,,of ,,crops4 ,reference has already been more than once made to the fact that a crop growing in any soil must necessarily exhaust it to a greater or less extent by withdrawing from it a certain quantity of the elements to which its fertility is due4 ,that this is the case has been long admitted in practice1 and it has also been established that the exhausting effects of different species of plants are very different2 that while some rapidly impoverish the soil1 others may be cultivated for a number of years without material injury1 and some even apparently improve it4 ,thus1 it is a notorious fact that white crops exhaust1 while grass improves the soil2 but the improvement in the latter case is really dependent on the fact1 that when the land is laid down in pasture1 nothing is removed from it1 the cattle which feed on its produce restoring all but a minute fraction of the mineral matters contained in their food2 and as the plants derive a part1 and in some instances a very large part1 of their organic constituents from the air1 the fertility of the soil must manifestly be increased1 or at all events maintained in its previous state4 ,when1 however1 the plant1 or any portion of it1 is removed from the soil1 there must be a reduction of fertility dependent on the quantity of valuable matters withdrawn by it2 and thus it happens that when a plant has grown on any soil1 and has removed from it a large quantity of nutritive matters1 it becomes incapable of producing an equally large crop of the same species2 and if the attempt be made to grow it in successive years1 the land becomes incapable of producing it at all1 and is then said to be thoroughly exhausted4 ,but if the exhausted land be allowed to lie for some time without a crop1 it regains its fertility more or less rapidly according to circumstances1 and again produces the same plant in remunerative quantity4 ,the observation of this fact led to the introduction of naked fallows1 which1 up to a comparatively recent period1 were an essential feature in agriculture4 ,but after a time it was observed that the land which had been exhausted by successive crops of one species was not absolutely barren1 but was still capable of producing a luxuriant growth of other plants4 ,thus peas1 beans1 clover1 or potatoes1 could be cultivated with success on land which would no longer sustain a crop of grain1 and these plants came into use in place of the naked fallow under the name of fallow crops4 ,on this was founded the rotation of crops2 for it was clear that a judicious interchange of the plants grown might enable the soil to regain its fertility for one crop at the time when it was producing another2 and when exhausted for the second1 it might be again ready to bear crops of the first4 ,the necessity for a rotation of crops has been explained in several ways4 ,the oldest view is that of ,decandolle1 who founded his theory on the fact that the plants excrete certain substances from their roots4 ,he found that when plants are grown in water1 a peculiar matter is thrown off by the roots2 and he believed that this extrementitious substance is eliminated because it is injurious to the plant1 and that1 remaining in the soil1 it acts as a poison to those of the same species1 and so prevents the growth of another crop4 ,but this excretion1 though poisonous to the plants from which it is excreted1 he believed to be nutritive to those of another species which is thus enabled to grow luxuriantly where the others failed4 ,nothing can be more simple than this explanation1 and it was readily embraced at the time it was propounded and considered fully satisfactory4 ,but when more minutely examined1 it becomes apparent that the facts on which it is founded are of a very uncertain character4 ,decandolle's observations regarding the radical excretions of plants have not been confirmed by subsequent observers4 ,on the contrary1 it has been shewn that though some plants1 when growing in water1 do excrete a particular substance in small quantity1 nothing of the sort appears when they are grown in a siliceous sand4 ,and hence the inference is1 that the peculiar excretion of plants growing in water is to be viewed as the result of the abnormal method of their growth rather than as a natural product of vegetation4 ,but even admitting the existence of these matters1 it would be impossible to accept the explanation founded upon them1 because it is a familiar fact that1 on some soils1 the repeated growth of particular crops is perfectly possible1 as1 for instance1 on the virgin soils of ,america1 from which many successive crops of wheat have been taken2 and in these cases the alleged excretion must have taken place without producing any deleterious effect on the crop4 ,besides1 it is in the last degree improbable that these excretions1 consisting of soluble organic matters1 should remain in the soil without undergoing decomposition1 as all similar substances do2 and even if they did1 we cannot1 with our present knowledge of the food of plants1 admit the possibility of the direct absorption of any organic substance whatever4 ,indeed1 the idea of radical excretions1 as an explanation of the rotation of crops1 must be considered as being entirely abandoned4 ,the necessity for a rotation of crops is now generally attributed to the different quantities of valuable matters which different plants remove from the soil1 and more especially to their mineral constituents4 ,it has been already observed that great differences exist in the composition of the ash of different plants in the section on that subject2 and it was stated that a distinction has been made between lime1 potash1 and silica plants1 according as one or other of these elements preponderate in their ashes4 ,the remarkable difference in the proportion of these elements has been supposed to afford an explanation of rotation4 ,it is supposed that if a plant requiring a large quantity of any one element1 potash1 for example1 be grown during a succession of years on the same soil1 it will sooner or later exhaust all1 or nearly all1 the potash that soil contains in an available form1 and it will consequently cease to produce a luxuriant crop4 ,but if this plant be replaced by another which requires only a small quantity of potash and a large quantity of lime1 it will flourish1 because it finds what is necessary to its growth4 ,in the meantime1 the changes which are proceeding in the soil1 are liberating new quantities of the inorganic matters from those forms of combination in which they are not immediately available1 and when after a time the plant which requires potash is again sown on the soil1 it finds a sufficient quantity to serve its purpose4 ,we have already1 in treating of the ashes of plants1 pointed out the extent of the differences which exist2 but these will be made more obvious by the annexed table1 giving the quantity of the different mineral matters contained in the produce of an imperial acre of the different crops4 ,,table shewing the quantities of ,mineral ,matters and ,nitrogen in average ,crops of the principal varieties of ,farm ,produce4 ---------------------------------------- ------------------------------- ,produce per ,total ,total ,imperial ,weight ,mineral ,potash4 ,soda4 ,lime4 ,acre4 in lbs4 ,matters4 ---------------------------------------- ------------------------------- ,wheat--,grain #bh bushels #a1fhj #cd4ab #aj4aa #a4bj #a4jd at #fj lbs4 ,straw #a ton #c cwt4 #b1egf #aad4dh #bj4gj #b4hd #h4ec ,total 444 444 #adh4fj #cj4ha #d4jd #i4eg ,barley--,grain #cc bushels #a1gdi #dd4bd #i4dj #j4cj #j4gf at #ec lbs4 ,straw #ah cwt4 #b1ajf #ii4ad #aa4bd #a4ad #e4ha ,total 444 444 #adc4ch #bj4fd #a4dd #f4eg ,oats--,grain #cd bushels #a1cfj #dh4hi #aa4jj 444 #e4ca at #dj lbs4 ,straw #a ton4 #b1bdj #adc4ec #cj4ga #f4aj #aj4bi ,total 444 444 #aib4db #da4ga #f4aj #ae4fj ,beans1 ,peas-- #be bushels #a1fej #ee4ig #cj4jj #j4ca #c4ja ,grain at #fj lbs4 ,straw #a ton4 #b1bdj #ajh4ea #dh4fa #ac4ad #bi4cg ,total 444 444 #afd4dh #gh4fa #ac4de #cb4ch ,turnips--,bulbs #ac-a_/b tons4 #cj1bdj #bac4ge #eg4ce #dd4ga #bh4fj ,potatoes #c tons4 #f1gbj #ee4eh #bh4ib #b4he #a4bj ,hay #b-a_/b tons4 #e1fjj #cia4ca #abi4gi #d4hj #ce4df ---------------------------------------- ------------------------------- ---------------------------------------- ------------------------------- ,magnesia4 ,chlor4 ,sulphuric ,phosphor ,silica4 ,nitro -ine ,acid4 -ic ,acid4 -gen4 ---------------------------------------- ------------------------------- ,wheat--,grain #d4hj 444 #j4cb #af4bb #j4dc #bi4bj ,straw #b4bc 444 #c4ee #c4af #gc4dg #af4ac ,total #g4jc 444 #c4hg #ai4ch #gc4ij #de4cc ,barley--,grain #c4aj #a4ab #j4he #ae4eb #ac4ai #cd4ih ,straw #b4ge #a4cj #a4aj #g4bb #fh4eh #f4jc ,total #e4he #b4db #a4ie #bb4gd #ha4gg #da4ja ,oats--,grain #d4jd #j4bj 444 #bf4jg #b4bg #bg4ed ,straw #e4ej #e4ee #e4ah #g4ce #gb4he #ad4aj ,total #i4ed #e4ge #e4ah #cc4db #ge4ab #da4fd ,beans1 ,peas-- #d4jj 444 #a4gf #af4fe #j4bd #df4aj ,grain ,straw #c4gd #g4jj #b4jg #j4gd #c4hd #bf4hh ,total #g4gd #g4jj #c4hc #ag4ci #d4jh #gb4ih ,turnips--,bulbs #d4fe #aj4ce #ci4jb #bb4eg #f4ej #fj4dh ,potatoes #b4aa #c4ba #aj4bd #e4gf #a4bi #bf4jj ,hay #i4fb #ci4fa #af4eg #ba4gi #acc4fg #ef4bb ---------------------------------------- ------------------------------- ,the minor constituents1 such as oxide of iron1 manganese1 etc41 have been omitted as being of little importance2 and the quantity of nitrogen1 which is of great moment in estimating the exhaustive effects of various crops1 has been added4 ,in examining this table1 it becomes apparent that while in regard to some of the elements1 the quantities removed by different crops do not differ to any marked extent1 in others the variation is very great4 ,the cereals and grasses are especially distinguished by the larger quantity of silica they contain1 and the exhaustive effect consequent upon the removal of both grain and straw from soils which contain but a limited supply of that substance in an available condition is obvious4 ,it is clear that under such circumstances the frequent repetition of a cereal crop may so far diminish the amount of available silica as to render its cultivation impossible1 although the other substances may be present in sufficient quantity to produce a plentiful crop of any plant which does not require that element4 ,beans and peas1 turnips and hay1 on the other hand1 require a very large quantity of alkalies1 and especially of potash4 ,looking more minutely1 however1 into this matter1 certain points attract attention which appear to be at variance with commonly received opinions4 ,with the exception of silica1 for example1 the cereals do not withdraw from the soil so large a quantity of mineral matters as some of the so-called fallow crops1 and if their straw be returned to the soil they are by far the least exhaustive of all cultivated plants2 and we thus recognise the justice of that practical rule1 which lays it down as an essential point of good husbandry that the straw ought1 as far as possible1 to be consumed on the farm on which it is produced4 ,as regards the general constituents of the ash1 it is also to be remarked that though differences in their proportions exist1 they are by no means so marked as might be expected2 thus there are no plants for which a large quantity of potash1 nitrogen1 and phosphoric acid is not required2 and it is not very easy to see how the substitution of the one for the other should be of much importance in this respect4 ,indeed1 the more minutely the subject is examined1 the more do we become convinced of the insufficiency of that view which attributes the necessity for a rotation of crops to differences in chemical composition alone4 ,there can be no doubt that the nature of the plant and the particular mode in which it gathers its nutriment1 have a most important influence4 ,certain plants are almost entirely dependent on the soil for their organic constituents1 while others derive a large proportion of them from the air1 and a plant of the latter class will flourish in a soil in which one of the former is incapable of growing4 ,in other cases1 the structure and distribution of the roots is the cause of the difference4 ,some plants have roots distributed near the surface and exhaust the superficial layer of the soil1 others penetrate into the deeper layers1 and not only derive an abundant supply of food from them1 but actually promote the fertility of the surface soil by the refuse portions of them which are left upon it4 ,experience has in this respect arrived at results which tally with theory1 and it is for this reason that the broad-leafed turnip1 which obtains a considerable quantity of its nutriment from the air1 alternates with grain crops which are chiefly dependent on the soil4 ,it is undoubtedly to some such cause that several remarkable instances of what may be called natural rotations are to be attributed4 ,it is well known in ,sweden that when a pine forest is felled1 a growth1 not of pine but of birch1 immediately springs up4 ,now the difference in composition of the ash of these trees is not sufficient to explain this fact1 and it must clearly be due to some difference in the distribution of their roots1 or the mode in which they obtain their food4 ,whatever weight may be given to these different explanations of rotation1 there is no doubt about the importance of attending to it1 and there are various practical deductions of much importance to be drawn from the facts with which we are acquainted4 ,thus it is to be observed that the quantities of mineral matters withdrawn by plants of the same class are generally similar1 and hence it may be inferred that crops of the most opposite class ought as much as possible to alternate with one another1 and each plant should be repeated as seldom as possible1 so that1 even when it is necessary to return to the same class1 a different member of it should be employed4 ,thus1 for instance1 in place of immediately repeating wheat1 when another grain crop is necessary1 it would theoretically be preferable to employ oats or barley1 and to replace the turnip by mangold-wurzel or some other root4 ,it is obvious1 however1 that this system cannot be carried out in practice to its full extent2 for the superior value of individual crops causes the more frequent repetition of those which make the largest return4 ,but experience has so far concurred with theory that it has taught the farmer the advantage of long rotations2 and we have seen the successive introduction of the three1 four1 five1 and six-course shift1 and even1 in some instances1 of longer periods4 ,such is the theory of rotation1 and while it will always be most advantageous to adhere to it1 it is by no means necessary that this should be done in an absolutely rigid manner4 ,in the practice of agriculture1 plants are placed in artificial circumstances1 and instead of allowing them to depend entirely on the soil1 they are supplied with a quantity of manure containing all the elements they require1 and if it be used in sufficiently large quantity1 the same crop may be grown year after year4 ,and accordingly the order of rotation1 which is theoretically the best1 may be1 and every day is1 violated in practice1 although this must necessarily be done at the expense of a certain quantity of the valuable matters of the manure added1 and is so far a practice which ought theoretically to be avoided4 ,in actual practice1 however1 the matter is to be decided on other grounds4 ,the object then is1 not to produce the largest crops1 but those which make the largest money return1 and thus it may be practically economical to grow a crop of high commercial value more frequently than is theoretically advantageous4 ,in such cases the farmer must seek to do away as far as possible with the disadvantages which such a course entails1 and this he will endeavour to accomplish by careful management and a liberal treatment of the soil4 ,but while this system may be adopted to some extent1 it must also be borne in mind that the frequent repetition of some crops cannot be practised with impunity1 for plants are liable to certain diseases which manifest themselves to the greatest extent when they have been too often cultivated in the same soil4 ,clover sickness1 which affects the plant when frequently repeated on light soils1 and the potatoe disease and finger and toe have been attributed to the same cause4 ,whether this is the sole origin of these diseases is questionable1 but there is no doubt that they are aggravated by frequent repetition1 and hence a strong argument in favour of rotation4 ,it has been asserted by great authorities in high farming1 that with our present command of manures1 rotations may be done away with2 but this is an opinion to which science gives no countenance1 and he would be a rash man who attempted to carry it out in practice4 ,,chapter ,,xiv4 ,,the ,,feeding ,,of ,,farm ,,stock4 ,the feeding of cattle1 once a subordinate part of the operations of the farm1 has now become one of its most important departments1 and a large number of minute and elaborate experiments have been made by chemists and physiologists with the view of determining the principles on which its successful and economical practice depends4 ,these investigations1 while they have thrown much light on the matter1 have by no means exhausted it1 and it will be readily understood that the complete elucidation of a subject of such complexity1 touching on so many of the most abstruse and difficult problems of chemistry and physiology1 and in which the experiments are liable to be affected by disturbing causes1 dependent on peculiarities of constitution of different animals1 cannot be otherwise than a slow process4 ,in considering the principles of feeding1 it is necessary to point out1 in the first instance1 that the plant and animal are composed of the same chemical elements1 hence the food supplied to the latter invariably contains all the substances it requires for the maintenance of its functions4 ,and not only is this the case1 but these elements are to a great extent combined together in a similar manner1--the fibrine1 caseine1 albumen1 and fatty matters contained in animals corresponding in all respects with the compounds extracted from plants under the same name2 and though the starchy and saccharine substances do not form any part of the animal body1 they are represented in the milk1 the food which nature has provided for the young animal4 ,it has been frequently assumed that the nitrogenous and fatty matters are simply absorbed into the animal system1 and deposited unchanged in its tissues2 but it is probable that the course of events is not quite so simple1 although1 doubtless1 the decomposition which occurs is comparatively trifling4 ,the starchy matters1 on the other hand1 are completely changed1 and devoted to purposes which will be immediately explained4 ,it is a matter of familiar experience1 that if the food be properly proportioned to the requirements of the animal1 its weight remains unchanged2 and the inference to be drawn from this fact obviously is1 that the food does not remain permanently in the system1 but must be again got rid of4 ,it escapes partly through the lungs1 and partly by the excretions1 which do not consist merely of the part which has not been digested1 but also of that portion which has been absorbed1 and after performing its allotted functions within the system1 has become effete and useless4 ,when the weights of the excretions1 the carbon contained in the carbonic acid expired by the lungs and the small quantity of matter which escapes in the form of perspiration1 are added together1 they are found in such a case to be exactly equal to the food4 ,if the animal be deprived of nutriment1 it immediately begins to lose weight1 because its functions must continue--carbon must still be converted into carbonic acid to maintain respiration--and the excretions be eliminated1 although diminished in quantity1 because they no longer contain the undigested portion of the daily food1 and the substances already stored up in the body are consumed to maintain the functions of life4 ,universal experience has shewn that1 under such circumstances1 the fat which has accumulated in various parts of the body disappears1 and the animal becomes lean2 but it is less generally recognised that the muscular flesh1 that is the lean part of the body1 also diminishes1 although it is sufficiently indicated by the fact that nitrogen still continues to be found in the urine1 and that the animal becomes feeble and incapable of muscular exertion4 ,respiration and secretion1 in fact1 proceed quite irrespective of the food1 which is only required to repair the loss they occasion4 ,when the course of events within the animal body is traced1 it is found to be somewhat as follows3 ,the food consumed is digested and absorbed into the blood1 where it undergoes a series of complicated changes1 as a consequence of which part of it is converted into carbonic acid1 and eliminated by the lungs1 and part is deposited in the tissues as fat and flesh4 ,after the lapse of a certain period1 longer or shorter according to circumstances1 a new set of actions comes into play1 by which the complex constituents of the tissues are resolved into simpler substances1 and excreted chiefly by the lungs and kidneys4 ,the changes thus produced are1 to a great extent1 identical with those which would take place if the fat and flesh were consumed in a fire2 and the animal frame may1 in a certain sense1 be compared to a furnace1 in which1 by the daily consumption of a certain quantity of fuel and air inhaled in the process of respiration1 its temperature is maintained above that of the surrounding atmosphere4 ,if the daily supply of fuel1 that is of food1 be properly adjusted to the loss by combustion1 the weight of the animal remains constant2 if it be reduced below this quantity1 it diminishes2 but if it be increased1 the stomach either refuses to digest and assimilate the excess1 or it is absorbed and stored up in the body1 increasing both the fat and flesh4 ,when an animal is fed in such a manner that its weight remains constant1 a balance is produced between the supply of nutriment contained in the food and the waste of the tissues1 the gain from the former exactly counterpoising the loss occasioned by the latter4 ,if in this state of matters an additional supply of food be given1 this balance is deranged1 and the nutriment being in excess of the loss1 the animal gains weight1 and it continues to do this for some time1 until it reaches a point at which a new balance is established1 and its weight again becomes constant2 and this is due to the fact that the animal becomes subject to an additional waste1 consequent on the increased weight of matter accumulated in its tissues4 ,if1 after the animal has attained its new constant weight1 the food be a second time increased1 a further gain is obtained1 and so on1 with every addition to the supply of nutriment1 until at length a certain point is reached1 beyond which its weight cannot be forced4 ,in fact1 each successive increase of weight is obtained at a greater expenditure of food4 ,if1 for example1 a lean animal is taken1 and its food increased by a given quantity1 it will rapidly attain a certain additional weight1 but if another extra supply of food be given1 the increase due to it will be much more slowly attained1 and so on until at length an additional increase can only be secured by the long-continued consumption of a very large quantity of food4 ,the great object of the feeder is to obtain the greatest possible increase with the smallest expenditure of food1 and to know the point beyond which it is no longer economical to attempt to force the process of fattening4 ,to do this it is necessary first to consider the composition of the animal itself1 then that of its food1 and lastly1 the mode in which it may be most economically used4 ,it has been already observed that the animal tissues are composed of albuminous or nitrogenous compounds1 fat1 mineral matters1 and water2 but the proportions of these substances have1 until lately1 been very imperfectly known4 ,water is well known to be by far the largest constituent1 and amounts in general to about two-thirds of the entire weight1 and it has been generally supposed that the nitrogenous matters stood next in point of abundance1 but a most important and elaborate series of experiments by ,messrs4 ,lawes and ,gilbert have shewn that they are greatly exceeded by the fatty matters4 ,the following table contains a summary of the composition of ten different animals in different stages of fattening4 ,the first division gives the composition of the carcass1 that is1 the portion of the animal usually consumed as human food2 the second that of the offal1 consisting of the parts not usually employed as food2 and the third that of the entire animals1 including the contents of the stomach and intestines3-- ,transcriber's note3 ,column titles are printed vertical1 which is not possible to do here4 ,therefore they are replaced with a #b-c character code1 explained here ,column titles3 ,,mm ,mineral ,matter ,,nc ,nitrogenous ,compounds ,,tds ,total ,dry ,substance ,,csi ,contents of ,stomachs and ,intestine in moist state4 ,wat ,water ---------------------------------------- ----------------------------------- ,per cent in ,offal1 excluding ,per cent in ,carcass contents of ,stomachs and ,intestines4 ---------------------------------------- ------------- ,,mm ,,nc ,fat ,,tds ,,wat ,,mm ,,nc ,fat ,,tds ,,wat ---------------------------------------- ------------------------ ,fat ,calf #d4dhaf4faf4fcg4gfb4c #c4da #ag4a #ad4f #ce4a #fd4i ,half-fat ,ox #e4efag4hbb4fdf4jed4j #d4je #bj4f #ae4g #dj4d #ei4f ,fat ,ox #d4efae4jcd4hed4dde4f #c4dj #ag4e #bf4c #dg4b #eb4h ,fat ,lamb #c4fcaj4icf4iea4ddh4f #b4de #ah4i #bj4a #da4e #eh4e ,store ,sheep #d4cfad4ebc4hdb4geg4c #b4ai #ah4j #af4a #cf4c #fc4g ,half-fat old ,sheep #d4acad4ica4cej4cdi4g #b4gb #ag4g #ah4e #ch4i #fa4a ,fat ,sheep #c4deaa4ede4dfj4cci4g #b4cb #af4a #bf4d #dd4h #ee4b ,extra fat ,sheep #b4gg #i4aee4afg4jcc4j #c4fd #af4h #cd4e #ed4i #de4a ,store ,pig #b4egad4jbh4add4gee4c #c4jg #ad4j #ae4j #cb4a #fg4i ,fat ,pig #a4djaj4edi4efa4dch4f #b4ig #ad4h #bb4h #dj4f #ei4d ---------------------------------------- ------------------------ ,mean of all #c4fiac4ecd4dea4fdh4d #c4jb #ag4b #ba4j #da4b #eh4h ---------------------------------------- ------------------------ ,mean of #h1 viz1 the half-fat1 fat1 and#c4geac4ccf4eec4fdf4d #c4ab #ag4d #bb4d #db4i #eg4a very fat animals ---------------------------------------- ------------------------ ,mean of #f1 viz41 of the fat and #c4chab4cci4gee4ddd4f #c4jc #af4i #bd4a #dd4j #ef4j very fat animals ---------------------------------------- ------------------------ ---------------------------------------- ---------- ,per cent in ,entire ,animal4 ------------------------------ ,,mm ,,nc ,fat ,,tds ,,csi ,,wat ---------------------------------------- ---- ,fat ,calf #c4hjae4bad4hcc4h #c4agfc4j ,half-fat ,ox #d4ffaf4fai4adj4c #h4aiea4e ,fat ,ox #c4ibad4ecj4adh4e #e4ihde4e ,fat ,lamb #b4idab4cbh4edc4g #h4eddg4h ,store ,sheep #c4afad4hah4gcf4g #f4jjeg4c ,half-fat old ,sheep #c4agad4jbc4edj4g #i4jeej4b ,fat ,sheep #b4haab4bce4fej4f #f4jbdc4d ,extra fat ,sheep #b4ijaj4ide4hei4f #e4ahce4b ,store ,pig #b4fgac4gbc4cci4g #e4bbee4a ,fat ,pig #a4feaj4idb4bed4g #c4igda4c ---------------------------------------- ---- ,mean of all #c4agac4ibh4bdd4i #f4acdi4j ---------------------------------------- ---- ,mean of #h1 viz1 the half-fat1 fat1 and#c4bcac4cbi4idf4d #f4bfdg4c very fat animals ---------------------------------------- ---- ,mean of #f1 viz41 of the fat and #c4jjab4gcb4hdh4e #e4dhdf4j very fat animals ---------------------------------------- ---- ,from this table it appears that1 in the carcass1 the proportion of fat is1 in general1 even in lean animals1 much greater than that of nitrogenous compounds4 ,in one case only1 that of the fat calf1 are they equal4 ,but in the lean sheep there is more than one and a half times as much fat as nitrogenous matters1 in the half fat sheep twice1 in the fat sheep four times1 and in the very fat sheep about six times as much4 ,as a general result of the analyses it may be stated1 that in the carcass of an ox in good condition1 the quantity of fat will be from two to nearly three times as great as that of the so called albuminous compounds2 in a sheep three or four times1 and in the pig four or five times as great4 ,in the offal1 including the hide1 intestines1 and other parts not usually consumed as food1 the proportion is very different1--the quantity of fat being much smaller1 and that of nitrogenous compounds considerably larger4 ,taking a general average of the whole1 the following may be assumed as representing approximately the general composition of a lean and a fat animal3-- ,lean4 ,fat4 ,mineral matters #e #c ,nitrogenous compounds #ae #ab4e ,fat #bd #cc ,water #ef #dh4e --- ----- #ajj #ajj4j ,the data given in the preceding table1 coupled with a knowledge of the relative weights of the lean and fat animals1 enable us to ascertain the composition of the increase during the fattening process4 ,it is obvious1 from the material diminution of the per centage of water1 that the matters deposited in the tissues must contain a much larger proportion of dry matters than the whole body2 and the reduced per centage of nitrogenous matters shews that the fat must also greatly preponderate4 ,this is still more distinctly illustrated by the following table1 giving the per centage composition of the increase in fattening oxen1 sheep1 and pigs3-- ---------------------------------------- -------- ,mineral ,nitrogenous ,fat4 ,water4 ,matters4 ,compounds4 ---------------------------------------- -------- ,oxen #a4dg #g4fi #ff4b #bd4f ,sheep #b4cd #g4ac #gj4d #bj4a ,pigs #j4jf #f4dd #ga4e #bb4j ---------------------------------------- -------- ,hence it may be stated in round numbers1 that for every pound of nitrogenous matters added to the weight of a fattening animal1 it will gain ten pounds of fat1 and three of water4 ,these are the proportions over the whole period of fattening1 but it is probable that during the last few weeks of the process the ratio of fat to nitrogenous matters is still higher4 ,in considering the composition of the food of animals1 it will be readily admitted that the milk1 the nutriment supplied by nature for the maintenance of the young animal1 must afford special instruction as to its requirements during the early stages of existence1 and indicate1 at least1 some of the points to be attended to under the altered conditions of mature life4 ,the following table gives the average composition of the milk of the most important farm animals3-- ,cow4 ,ewe4 ,goat4 ,caseine #c4d #d4ej #d4jb ,butter #c4f #d4bj #c4cb ,sugar of milk #f4j #e4jj #e4bh ,ash #j4b #j4fh #j4eh ,water #hf4h #he4fb #hf4hj ------ ------ ------ #ajj4jj #ajj4jj #ajj4jj ,in examining these1 and all other analyses of food1 it is necessary to draw a distinction between the flesh-forming and the respiratory elements2 the former including the nitrogenous compounds which are used in the production of flesh1 the latter1 the non-nitrogenous substances which produce fat and support the process of respiration4 ,the former1 however much they may differ in name1 are nearly or altogether identical in chemical composition1 the latter embracing two great classes--the fats which exist in the body and the saccharine compounds1 including the different kinds of sugar and starch which are not found in the animal tissues4 ,it was at one time supposed that these substances were entirely consumed in the respiratory process1 and eliminated by the lungs in the form of carbonic acid and water1 but it has been clearly shewn that they may be and often are converted into fat1 and accumulated in the system4 ,careful experiments on bees have demonstrated that when fed on sugar they continue to produce wax1 which is a species of fat1 and animals retain their health and become fat1 even when their food contains scarcely any oil4 ,there is1 however1 an important difference between these two classes of substances as regards their fat-producing effect4 ,a pound of fat contained in the food is capable of producing the same quantity within the animal2 but the case is different with starch and sugar1 the most trustworthy experiments shewing that two and a half pounds of these substances are necessary for that purpose4 ,hence we talk of the fat equivalent of sugar1 by which is meant the amount of fat it is capable of producing1 and which is obtained by dividing its quantity by #b4e4 ,applying this principle to the analyses of the milk1 it appears that the relative proportions of the two great classes of nutritive substances stand thus3-- ,flesh ,respiratory1 expressed in forming their fat equivalent ,cow #c4d #f4j ,ewe #d4e #f4b ,goat #d4j #e4d ,taking the general average1 it may be stated1 that for every pound of flesh-forming elements contained in the food of the sucking animal1 it consumes respiratory compounds capable of producing one and a half pounds of fat1 and this does not differ materially from the ratio subsisting between these substances in the lean animal4 ,when the young animal is weaned1 it obtains a food in which the ratio of nitrogenous to respiratory elements is maintained nearly unchanged2 but the latter1 in place of containing a large amount of fatty matters1 is in many cases nearly devoid of these substances1 and consists almost exclusively of starch and sugar1 mixed most commonly with a considerable quantity of woody fibre4 ,a very large number of analyses of different kinds of cattle food have been made by chemists1 but our information regarding them is still in some respects imperfect4 ,the quantity of nitrogenous compounds and of oil has been accurately ascertained in almost all1 but the amount of starch1 sugar1 and woody fibre is still imperfectly determined in many substances4 ,this is due partly to the fact that the nitrogenous and fatty matters were formerly believed to be of the highest importance1 and might be used as the measure of the nutritive value of food to the exclusion of its other constituents1 and partly also to the imperfect nature of the processes in use for obtaining the amounts of woody fibre1 starch1 and sugar4 ,these difficulties have now1 to a certain extent1 been overcome1 and the quantity of fibre and of respiratory elements has been ascertained1 and is introduced1 so far as is known1 in the subjoined table3-- ,,table giving the ,composition of the ,principal ,varieties of ,cattle ,food4 ,note4--,where a blank occurs in the oil column1 the quantity of that substance is so small as to be unimportant4 ,when the respiratory elements and fibre have not been separated1 the sum of the two is given4 ---------------------------------------- ------------------------------ ,nitro- ,oil4 ,respir- ,fibre4 ,ash4 ,water4 genous tory ,com- ,com- pounds4 pounds4 ---------------------------------------- ------------------------------ ,decorticated earth-nut cake #dd4jj #h4hf #ai4cd #e4ac #ad4je #h4fb ,decorticated cotton cake #da4be #af4je #af4de #h4ib #h4je #i4bh ,poppy cake #cd4jc #aa4jd #bc4be #aa4cc #ac4gi #f4ef ,teel or sesamum cake #ca4ic #ab4hf #ba4ib #i4jf #ac4he #aj4ch ,rape cake #bi4ge #h4fc #ch4gb #g4cj #h4fe #f4ie ,dotter cake #bi4jj #g4ii #bg4jd #af4ab #ab4ei #g4bf ,tares1 home-grown #bh4eg #a4cj #eh4fd #b4ej #h4ii ,linseed cake #bh4ec #ab4dg #ce4gh #f4cb #f4aa #aj4gi ,ruebsen cake #bf4hg #aa4jj #ca4dg #af4ie #h4jj #e4ga ,tares1 foreign #bf4gc #a4ei #ec4jd #b4hd #ae4hj ,earth-nut cake 7entire seed7 #bf4ga #ab4ge #de4fi #c4bi #aa4ef ,niger cake #be4gd #f4eh #db4ah #aa4ae #h4ab #f4bc ,beans 7#fe lbs4 per bushel7 #bd4gj #a4ei #ed4ea #c4cf #ae4hd ,lentils #bd4eg #a4ea #eh4hb #b4gi #ab4ca ,linseed #bd4dd #cd4jj #cj4gc #c4cc #g4ej ,grey peas #bd4be #c4cj #eg4ii #b4eb #aa4id ,foreign beans #bc4di #a4ea #ei4fg #c4ad #ab4ba ,cotton cake 7with husk7 #bb4id #f4jg #cf4eb #af4ii #f4jb #aa4df ,pea-nut cake #bb4be #g4fb #cj4be #bf4ig #c4ga #i4bj ,sunflower cake #ba4fh #h4id #ai4je #cc4jj #i4cc #h4jj ,hempseed cake #ba4dg #g4ij #bb4dh #be4af #ae4gi #g4ba ,kidney beans #bj4jf #a4bb #fb4af #c4ef #ac4jj ,maple peas #ai4dc #a4gb #fc4ah #b4jd #ac4fc ,madia sativa 7seed7 #ah4da #cf4ee #cd4ei #d4ac #f4cb ,clover hay 7mean of different species of clover7 #ae4ha #c4ah #cd4db #bb4dg #g4ei #af4ec ,rye #ad4bj 444 #ha4ea #b4dg #a4hb #ad4ff ,bran #ac4hj #e4ef #fa4fg #f4aa #ab4he ,oats #aa4he #e4hi #eg4de #i4jj #b4gb #ac4ji ,fine barley dust #aa4di #b4ib #ga4da #b4fg #aa4ea ,wheat #aa4dh 444 #gc4eb #j4fh #j4hb #ac4ej ,bere #aj4be 444 #fb4he #aj4jh #b4fj #ad4bb ,hay 7mean of different grasses7 #i4dj #b4ef #ch4ed #bi4ad #e4hd #ad4cj ,barley #h4fi 444 #fd4eb #i4fg #b4hb #ad4cj ,coarse barley dust #h4df #c4dg #fi4gc #g4ca #aa4jc ,rice dust #h4jh #b4ie #fi4bb #h4ab #aa4fc ,oat dust #f4ib #c4ba #gb4hf #g4gj #i4ca ,winter bean straw #e4ga 444 #fg4ej #f4ci #bj4dj ,carob bean #c4aa #j4da #fb4ea #ah4fj #b4hj #ab4eg ,potato #b4ha 444 #ag4cj #a4jg #a4ac #gg4fi ,carrot #a4hg 444 #g4ia #c4jg #a4aa #hf4jd ,wheat straw #a4gi 444 #ca4jf #de4de #g4dg #ad4bc ,barley straw #a4fh 444 #ci4ih #ci4hj #d4bd #ad4cj ,oat straw #a4fc 444 #cg4hf #dc4fj #d4ie #ab4jf ,mangold-wurzel #a4ed 444 #h4fj #a4ab #j4if #hg4gh ,cabbage #a4ca 444 #d4ec #a4je #ic4aa ,turnips #a4bg #j4bj #d4jg #a4jh #a4ga #ia4dg ---------------------------------------- ------------------------------ ,it is at once obvious that in many of these descriptions of food the ratio of the flesh to the fat-forming constituents differ very widely from that existing in the milk1 and this becomes still more apparent when the latter are represented in their fat equivalent1 as is done for a few of them in the following table3-- ,flesh ,respiratory1 expressed forming1 in their fat equivalent1 ,decorticated earth-nut cake #dd4j #af4f ,linseed cake #bh4e #bf4g ,tares #bf4gc #ah4h ,clover hay #ae4ha #af4h ,oats #aa4he #bh4h ,hay 7mean of grasses7 #i4dj #ag4i ,potato #b4ha #f4i ,wheat straw #a4gi #ab4d ,turnip #a4bg #a4h ,it is especially note-worthy that those varieties of food1 which common experience has shewn to promote the fattening of stock to the greatest extent1 contain in many instances the smallest quantity of respiratory or fat-forming elements relatively to their nitrogenous compounds4 ,this is especially the case with the different kinds of oil cake1 the leguminous seeds1 clover1 hay1 and turnips4 ,on the other hand1 in the grains the ratio is nearly that of one to three1 or similar to that found in fat cattle2 while in the straw1 the excess of the respiratory elements is extremely great4 ,these facts appear at first sight to be completely at variance with the composition of the increase of fattening animals1 as ascertained by ,messrs4 ,lawes and ,gilbert already referred to1 and which have shewn that for every pound of nitrogenous compounds1 nearly ten pounds of fat are stored within the animal2 and it might be supposed that those kinds of food which contain the largest relative amount of respiratory elements ought to fatten most rapidly1 and should be selected by the farmer in preference to oil-cakes and similar substances4 ,but there are other matters to be considered1 dependent on the complex nature of the changes attending the absorption and assimilation of the food4 ,it must be particularly borne in mind that only a small proportion of the food consumed is stored up within the body1 and goes to increase the weight of the animal4 ,even in the case of the milk1 in which economy in the supply of nutritive matters has been most clearly attended to by nature1 a considerable proportion escapes assimilation1 and in the adult animal a large amount of the food passes off with the excretions4 ,the justice of this position is apparent when it is remembered that an ox will go on day after day consuming from a hundred weight to a hundred weight and a half of turnips1 three or four pounds of bean-meal or oil-cake1 and a considerable quantity of straw1 although its daily increase in live weight may not exceed a couple of pounds4 ,and in this direction a very fertile field of inquiry lies open to the agricultural experimenter2 for it would be most important to determine whether there are not some substances from which the nutritive matters may not be more easily assimilated than from others1 and what proportion of each is absorbable under ordinary circumstances4 ,on this point no information has yet been obtained applicable to individual feeding substances1 but the experiments of ,messrs4 ,lawes and ,gilbert have shewn the quantity of the total food1 and of each of its constituents1 stored up in the fattening animal1 and a summary of their results is contained in the following ,table3-- ,,table shewing the ,amount of each ,class of ,constituents1 stored in the increase1 for #ajj consumed in the ,food4 ---------------------------------------- ------ ,mineral ,nitrogenous ,total ,dry ,matters ,compounds4 ,fat4 ,substance4 ---------------------------------------- ------ ,sheep #c4bg #d4da #i4d #h4jf ,pigs #j4eh #g4cd #ba4b #ag4c ---------------------------------------- ------ ,hence it appears that the pig makes a better use of its food than the sheep1 retaining twice as much of its solid constituents within the body1 from which may be deduced the important practical conclusion1 that the former must be fattened at a much smaller cost than the latter4 ,looking at the individual constituents1 it appears that1 in the sheep1 less than one-twentieth of the nitrogenous compounds1 and one-tenth of the non-nitrogenous substances contained in the food1 remain in the body2 and a knowledge of these facts tends to modify the conclusions which might be drawn from the composition of the increase in the fattening animal4 ,its influence may be best illustrated by a particular example4 ,if1 for instance1 the increase in a sheep contained its nitrogenous and respiratory elements in the ratio of #a to #aj1 it would be totally incorrect to supply these substances in the food in the same proportions4 ,on the contrary1 it would be necessary at the very least to double the proportion of the former1 because one-tenth of the fat-forming elements are absorbed1 and only one-twentieth of the nitrogenous4 ,on further consideration1 also1 it seems unquestionable that the quantity of the nutritive elements stored up must depend to a large extent on the nature of the food and the particular state in which they exist in it4 ,it is probable1 or at least possible1 that some kinds of food may contain their nitrogenous constituents in an easily assimilable state1 and their respiratory elements in a nearly indigestible condition1 or vice versa1 and under these circumstances their nutritive value would be below that indicated by analysis2 but these points can only be determined by elaborate and long continued feeding experiments4 ,it is well known1 however1 that the mechanical state of the food has a most important influence on its nutritive value4 ,thus1 for example1 the presence of a large quantity of woody fibre protects the nutritive substances from assimilation1 and seeds with hard husks pass unchanged through the animal1 although1 so far as their composition alone is concerned1 they may be highly nutritive2 and the loss of a certain quantity of many varieties of food in this way is familiar to every one4 ,the proper adjustment of the relative quantities of the great groups of nutritive elements in the food is a matter the importance of which cannot be over-rated1 for it is in fact the foundation of successful and economical feeding2 and this will be readily understood if we consider what would be the result of giving to an animal a supply of food containing a large quantity of nitrogenous and a deficiency of fat-forming compounds4 ,in such circumstances1 the animal must either languish for want of the latter1 or it is forced to supply the defect by an increased consumption of food1 in doing which it must take into the system a larger quantity of nitrogenous compounds than would otherwise have been requisite1 and in this way the other elements1 which are present in abundance1 are wasted1 and the theoretical and practical value of a food so constituted may be very different1 and it is only when the proportions of the different groups are properly attended to that the most economical result can be obtained4 ,it can scarcely be said that the experiments yet made by feeders enable us to fix the most suitable proportion in which those substances can be employed1 although experience has led them to the use of mixtures which are in most cases theoretically correct2 thus they combine oil-cakes or turnips with straw1 which is poor nitrogenous1 and rich in fat-forming elements2 and in general it will be found that where different kinds of food are mixed1 the deficiencies of the one are counterbalanced by the other1 and though this has hitherto been done empirically1 it cannot be doubted that as our knowledge advances it will more and more be determined by reference to the composition of the food4 ,although the presence of a sufficient quantity of nutritive compounds in the food is necessarily the fundamental matter for consideration1 its bulk is scarcely less important4 ,the function of digestion requires that the food shall properly fill the stomach1 and however large the supply of nutritive matters may be1 their effect is imperfectly brought out if the food is too small in bulk1 and it actually may become more valuable if diluted with woody fibre1 or some other inert substance4 ,at first sight this may appear at variance with the observations already made as to the effects of woody fibre in protecting the nutritive matters from absorption2 but practically there are two opposite evils to be contended against1 a food having too small a bulk1 or one containing so large a proportion of inert substances as to become disadvantageously voluminous4 ,the most favourable condition lies between the two extremes1 and the natural food of all herbivorous animals is diluted with a certain amount of woody fibre4 ,when these are replaced by substances containing a large quantity of nutritive matters in a small bulk1 the result is that the natural instinct of the animal causes it to continue feeding until the stomach is properly distended1 and it consequently consumes a much larger quantity of food than it is capable of digesting1 and a more or less considerable quantity passes unchanged through the intestines1 and is lost4 ,on the other hand1 if the food be too bulky1 the sense of repletion causes the animal to cease eating long before it has obtained a sufficient supply of nutritive matter4 ,it is most necessary1 therefore1 to study the mixture of different kinds of food1 so as to obtain a proper relation between the bulk and the nutritive matters contained in the mixture2 and on examining the nature of the mixed foods most in vogue among feeders1 it will be found that a very bulky food is usually conjoined with another of opposite qualities4 ,hence it is that turnips1 the most voluminous of all foods1 are used along with oil-cake and bean-meal1 and if from any circumstances it becomes necessary to replace a large amount of the former by either of the latter substances1 the deficient bulk must be replaced by hay or straw4 ,it has been already remarked that there are three great purposes to which the food consumed is appropriated2 the increase of weight of the animal--the object the feeder has in view and desires to promote--the supplying the waste of the tissues1 and the process of respiration1 both of which are sources of loss of food1 and which it must necessarily be his aim to diminish as much as possible4 ,the circumstances which must be attended to in order to do this are sufficiently well understood4 ,it has been clearly established that the natural heat of the animal is sustained by the consumption of a certain quantity of its food in the respiratory process1 during which it undergoes exactly the same changes as those which occur during combustion4 ,it has further been observed1 that the temperature of the body remains unchanged1 whatever be that of the surrounding air2 and it is obvious that if it is to continue the same in winter as in summer1 a larger quantity of fuel 7i4 e4 food7 must be consumed for this purpose1 just as a room requires more fire to keep it warm in winter than in summer1 and hence it naturally follows1 that if the animal be kept in a warm locality the food is economized4 ,it may also be inferred that1 if it were possible1 consistently with the health of the animal1 to keep it in a room artificially heated to the temperature of its own body1 this source of waste of food would be entirely removed4 ,it is not possible1 however1 to do this1 because a limit is set to it by physiological laws1 which cannot be infringed with impunity2 but the housing of cattle1 so as to diminish this waste as far as possible1 is a point in regard to the propriety of which theory and practice are at one4 ,the old feeders kept their cattle in large open courts1 where they were exposed to every vicissitude of the weather1 but as intelligence advanced1 we find them substituting1 first hammels1 and then stalls1 in which the animals are kept during the whole time of fattening at an equable temperature4 ,the effect of this is necessarily to introduce a considerable economy of the food required to sustain the animal heat2 but it also produces a saving in another way1 for it diminishes the waste of the tissues4 ,it has been ascertained by accurate experiments made chiefly on man1 that muscular exertion is one of the most important causes of the waste of the tissues1 and of increased respiratory activity4 ,we cannot move a limb without producing a corresponding consumption of matters already laid up within the body2 and it has also been found1 that the difference in the quantity of carbonic acid expired during rest and active exertion1 is very large4 ,the inference to be drawn from this is1 that when it is sought to fatten an animal rapidly1 every effort must be made to restrain muscular motion so far as compatible with health4 ,hence1 the peculiar advantage of stall-feeding1 in which the animal is confined to one spot1 and the more thoroughly it can be kept still1 the greater will be the economy of food4 ,this is gained by darkening the house1 and excluding all persons1 except when their presence is indispensable4 ,an extension of the same principle has led to the use of food artificially heated1 but it is doubtful whether the advantages derived from it are commensurate to the increased expense of the process2 at least opinions differ among the best informed practical men on this subject4 ,many other matters1 besides these mentioned1 exercise an important influence on the feeding of stock1 such as the general health of the animal1 the breed1 etc4 ,these are subjects1 however1 which bear more directly on practical agriculture1 and need not be discussed here4 ,the judicious feeder will not only give due weight to the principles already discussed in all he does1 but he must take into consideration the extent to which they are liable to be modified in particular cases4 ,he must also attend to the cost of different kinds of food1 and the value of the manure produced by them1 subjects of much importance in a practical point of view1 and which must influence him greatly in choice of the particular substances he supplies to his cattle4 ,,index4 ,acid1 apocrenic1 #ba4 ,carbonic1 #aj1 #ae1 #bj1 #cg1 #eg1 #aae4 ,cerotic1 #dh4 ,crenic1 #ba4 ,geic1 #ba4 ,hippuric1 #afh4 ,humic1 #ba4 ,lactic1 #afh4 ,margaric1 #dg4 ,nitric1 #aa1 #ag1 #cj1 #cc1 #ch1 #fb1 #aab4 ,oleic1 #dg4 ,pectic1 #df4 ,phosphoric1 #gc1 #ij4 ,stearic1 #dg4 ,sulphuric1 #ahb1 #bcg4 ,ulmic1 #ba4 ,uric1 #afh4 ,adulteration of guano1 #baa4 ,agricultural ,chemistry ,association of ,scotland1 #f4 ,air1 influence of1 on germination1 #ee4 ,in the pores of soils1 #aae4 ,albite1 #hf4 ,albumen1 #dh4 ,albuminous constituents of plants and animals1 #dh4 ,algoa ,bay guano1 #bjh4 ,alkaline salts1 value of1 #bfj4 ,alumina1 #gc1 #hf1 #ajc4 ,ammonia1 absorption of1 by plants1 #bi1 #ch4 ,absorption of1 by soils1 #abc4 ,carbonate of1 #bi4 ,composition of1 #ab4 ,decomposition of1 by plants1 #fa4 ,presence in dew1 #ag4 rain1 #ag4 ,production of1 #ab4 ,properties of1 #ab4 ,proportion of1 in air1 #af1 #bj4 ,proportion of1 in drain water1 #aab4 ,proportion of1 in soils1 #ajg4 ,sulphate of1 #bi1 #bbg4 ,sulphomuriate of1 #bbg4 ,urate of1 #bje4 ,valuation of1 #bei4 ,ammoniacal liquor1 #bbi4 ,amylaceous constituents of plants1 #dj4 ,angamos guano1 #bjg1 #baj4 ,animal charcoal1 #bbd4 ,manures1 #bjd4 ,animals1 composition of1 #bha4 ,nitrogenous constituents of1 #dh1 #bha4 ,apatite1 #bce4 ,ascension ,island guano1 #bjh4 ,augite1 #hi4 ,australian guano1 #bjg4 ,avenine1 #ej4 ,barks1 amount of ash in1 #ff4 ,barley1 #bhf4 ,barrenness of soils1 #aji4 ,basalt1 #ib4 ,beans1 #bhf4 ,bere1 #bhf4 ,biphosphate of lime1 #bcg1 #bfj4 ,bird ,island guano1 #bjh4 ,blood as a manure1 #bbj4 ,bone ash1 #bcd4 ,bone oil1 #bbi4 ,bones as a manure1 #bbc4 ,dissolved1 #bcg4 ,box-feeding1 #ahc4 ,bolivian guano1 #bjg1 #baj4 ,bran1 #aig1 #bhf4 ,burning1 improvement of soils by1 #adf4 ,cabbage1 #bhf4 ,cane sugar1 #dc4 ,carbon1 properties of1 #aj4 ,proportion of1 in plants1 #aj4 ,carbonate of ammonia1 #bi4 ,lime1 #if1 #bdg4 ,magnesia1 #if4 ,potash1 #bcb4 ,soda1 #bcb4 ,carbonic acid1 absorption of1 by plants1 #cg4 ,decomposition of1 by plants1 #eg4 ,evolution of1 by plants1 #eh4 ,how obtained1 #aj4 ,properties1 #aj4 ,proportion of1 in air1 #ae1 #bj4 ,carburetted hydrogen1 #ai4 ,calcium1 sulphuret of1 #beb4 ,caramel1 #dd4 ,carrot1 #bhf4 ,caseine1 #ej1 #bhc4 ,castor cake1 #aie4 ,cattle food1 composition of1 #bhf4 ,cellulose1 #dj4 ,cerine1 #dh4 ,cerotic acid1 #dh4 ,chaff1 #aig4 ,chalk1 #if1 #bde4 ,charcoal1 animal1 #bbd4 ,chilian guano1 #bjg4 ,china-clay1 #hg4 ,chloride of potassium1 #gc1 #ajb4 ,sodium1 #gc1 #bcb4 ,manganese1 #ahb4 ,clay1 #hg4 ,absorbent action of1 #aba4 ,composition of1 #ie4 ,source of1 #hh1 #id4 ,clay-slate1 #ie4 ,classification of plants1 #ha4 ,coprolites1 #ih1 #bce4 ,coral sand1 #bdf4 ,cotton cake1 #aie1 #bhf4 ,crenic acid1 #ba4 ,crops1 ,mineral matters in1 #bgj4 ,nitrogen in different1 #bgj4 ,rotation of1 #ha1 #bff4 ,deep ,ploughing1 effects of1 #add4 ,dew1 ammonia in1 #ag4 ,nitric acid in1 #ai4 ,dextrine1 #dc4 ,diastase1 #dc1 #ec1 #ee4 ,diorite1 #ib4 ,dissolved bones1 #bcg4 ,dolerite1 #ib4 ,dotter cake1 #bhf4 ,drainage water1 analyses of1 #aab4 ,draining1 #ach4 ,dung1 composition of1 #agj4 ,dung heaps1 management of1 #agi4 ,earth-nut cake1 #bhf4 ,emulsine1 #ej4 ,exhaustion of soils1 #ha4 ,farm stock1 feeding of1 #bgf4 ,farm-yard manure1 #aff1 #agb4 ,application of1 #ahf4 ,fat1 amount of1 in animals1 #bha4 ,fatty acids1 #dg4 ,matters1 #df4 ,feeding cakes1 #bhf4 ,feeding of farm stock1 #bgf4 ,felspar1 #hf4 ,decomposition of1 #hh4 ,fermentation of manure1 #ahd4 ,fire-clay1 #ie4 ,fish manure1 #bba4 ,flesh as a manure1 #bbj4 ,fog1 ammonia in1 #ag4 ,nitric acid in1 #ai4 ,food1 cattle1 #bhf4 ,fruits1 amount of ash in1 #ff4 ,gas ,lime1 #beb4 ,geic acid1 #ba4 ,germination1 #ed4 ,gluten1 #di4 ,glutin1 #di4 ,glycerine1 #dg4 ,gneiss1 #ia4 ,granite1 #ia4 ,grape sugar1 #dd4 ,greenstone1 #ib4 ,green manuring1 #aih4 ,guano1 #bjd4 ,adulteration of1 #baa4 ,application of1 #bad4 ,average composition of1 #bjg4 ,fish1 #bbb4 ,peruvian1 characters of1 #bji4 ,phospho-,peruvian1 #bdc4 ,sombrero ,island1 #bcf4 ,hair1 #bah4 ,hay1 #bhf4 ,heat1 evolution of1 by plants1 #fj4 ,hempseed cake1 #bhf4 ,hippuric acid1 #afh4 ,horn1 #bah4 ,hornblende1 #hi4 ,humic acid1 #ba4 ,humin1 #bb4 ,humus1 #ba1 #ih1 #acc4 ,hydrogen1 #aj4 ,ichaboe ,guano1 #bjg4 ,indian guano1 #bjh4 ,inorganic constituents of plants1 #i1 #cd4 ,inorganic constituents2 ,absorption by plants1 #ch4 ,proportion in plants1 #fd4 ,inorganic constituents of soils1 #he4 ,inuline1 #dc4 ,iodine in plants1 #gf4 ,iron1 protoxide of1 in soils1 #ajg4 ,sulphate of1 #ahb4 ,sulphuret of1 in subsoils1 #ace4 ,kaolin1 #hg4 ,kooria ,mooria guano1 #bjg4 ,labradorite1 #hf4 ,lactic acid1 #afh4 ,latham ,island guano1 #bjg4 ,leaves1 amount of ash in1 #fe4 ,as a manure1 #bjb4 ,legumine1 #ej4 ,lichen starch1 #db4 ,light1 influence of1 on plants1 #eg4 ,lime1 action of1 on soils1 #bdh4 ,as a manure1 #bde4 ,bicarbonate of1 #abb4 ,carbonate of1 #if4 ,biphosphate of1 #bcg1 #bfj4 ,humate of1 #abe ,phosphate of1 #if1 #bcc1 #beh4 ,sulphate of1 #if1 #bec1 #bfj4 ,lime-plants1 #hb4 ,limestone1 #if4 ,linseed cake1 #aie4 ,liquid manure1 #aff1 #ahg4 ,madia ,sativa1 #bhf4 ,magnesia1 carbonate of1 #if4 ,sulphate of1 #ahb1 #bcc4 ,magnesian limestone1 #if4 ,malt-dust1 #aig4 ,manganese in plants1 #gc4 ,oxide of1 #gc1 #hg4 ,chloride of1 #ahb4 ,mangold-wurzel1 #bhf4 ,manures1 animal1 #bjd4 ,manures1 application of1 #afe1 #ahf4 ,fermentation of1 #ahd4 ,farm-yard1 #aff1 #agb4 ,liquid1 #aff1 #ahg4 ,mineral1 #bbf4 ,theory of1 #aef4 ,sewage1 #aia4 ,vegetable1 #aie4 ,valuation of1 #bee4 ,manuring1 ,green1 #aih4 ,principles of1 #aeb4 ,maple peas1 #bhf4 ,maracaybo guano1 #bcf4 ,margaric acid1 #dg4 ,margarine1 #df4 ,marl1 #bde4 ,mexican guano1 #bjg4 ,mica1 #hh4 ,mica slate1 #ia4 ,milk1 composition of1 #bhc4 ,curding of1 #ea4 ,mineral constituents of plants1 #i1 #fc4 ,mineral manures1 #bbf4 ,mineral matters in different crops1 #bgj4 ,in animals1 #bha4 ,moisture1 influence of1 on germination1 #ee4 ,mucilage1 #dd4 ,natrolite1 #ij4 ,new ,island guano1 #bjh4 ,niger cake1 #bhf4 ,night-soil1 #bag4 ,nitrate of potash1 #bbi4 ,nitrate of soda1 #bbi1 #bfj4 ,nitric acid1 absorbtion of1 by plants1 #cj1 #ch4 ,decomposition of1 by plants1 #fb4 ,in drainage water1 #aab4 ,in dew1 #ai4 ,in air1 #ag4 ,in fog1 #ai4 ,production of1 #aa1 #cc4 ,nitrification1 #aa4 ,nitrogen1 amount in a six-course rotation1 #afj4 ,amount of1 in different crops1 #bgj4 ,presence in the atmosphere1 #aa4 ,properties of1 #aa4 ,proportion of1 in plants1 #aa4 ,nitrogenous constituents of plants1 #dh1 #bhf4 ,nitrogenous constituents of animals1 #dh1 #bha4 ,oats1 #bhf4 ,proportion of ash in1 #fh1 #gj4 ,oil-cakes1 #aie1 #bhf4 ,oils1 sweet principle of1 #dg4 ,oily matters1 #df4 ,oleic acid1 #dg4 ,oleine1 #df4 ,oligoclase1 #hf4 ,oolitic limestone1 #if4 ,organic constituents of plants1 #h4 ,sources of the1 #ac1 #bj4 ,organic constituents of soils1 #ajc4 ,orthoclase1 #hf4 ,oxide of iron in rocks and soils1 #hg1 #ajg4 ,of manganese1 #hg4 ,oxygen1 evolution of1 by plants1 #eh4 ,influence of1 on germination1 #ee4 ,presence in atmosphere1 #ab4 ,properties of1 #ab4 ,proportion of1 in plants1 #ab4 ,pacquico ,guano1 #bjg4 ,paring1 improvement of soils by1 #adf4 ,patagonian guano1 #bjg4 ,pea-nut cake1 #bhf4 ,peas1 #bhf4 ,peat1 as a manure1 #bjc4 ,peat1 use of1 in dung-heaps1 #ahd4 ,pectic acid1 #df4 ,pectine1 #df4 ,peruvian ,guano1 #bje1 #bjg1 #bji4 ,upper1 #bjg1 #bac4 ,phosphate of lime1 #if1 #bcc4 ,value of1 #beh4 ,phosphates1 insoluble1 #beh4 ,soluble1 #bcg1 #bfj4 ,phospho-,peruvian guano1 #bdc4 ,phosphuretted hydrogen in air1 #ai4 ,pigeons' dung1 #baf4 ,plants1 ,albuminous constituents of1 #dh4 ,amylaceous constituents of1 #dj4 ,ash of1 #fd1 #gc4 ,classification of1 #ha4 ,inorganic constituents of1 #i1 #cd1 #ch1 #fc4 ,oily constituents of1 #df4 ,organic constituents of1 #h4 ,proximate constituents of1 #dj4 ,saccharine constituents of1 #dj4 ,poppy cake1 #aif1 #bhf4 ,potash1 carbonate of1 #bcb4 ,muriate of1 #bca4 ,nitrate of1 #bbi4 ,plants1 #hb4 ,salts1 #bca4 ,potato1 #bhf4 ,poudrette1 #bag4 ,proximate constituents of plants1 #dj4 ,pyroguanite1 #bcf4 ,quartz1 #hf4 ,rainwater1 #ag1 #ah4 ,rape ,cake1 #aif1 #bhf4 ,dust1 #aie4 ,rocks1 crystalline1 #he4 ,composition of1 #ia4 ,disintegration of1 #he4 ,sedimentary1 #hf4 ,roots of plants1 amount of ash in1 #fe4 ,rotation of crops1 #ha1 #bff4 ,ruebsen cake1 #bhf4 ,rye1 #bhf4 ,saccharine ,constituents of plants1 #dj4 ,saldanha ,bay guano1 #bjg4 ,salt1 common1 #bcb4 ,sandstones1 #ie4 ,schuebler's experiments1 #abg4 ,sea ,bear ,bay guano1 #bjh4 ,sea weed1 #bjj1 #bja4 ,seeds1 amount of ash in1 #fd4 ,sesamum cake1 #bhf4 ,sewage manure1 #aia4 ,shell sand1 #bdf4 ,silica plants1 #hb4 ,silicate of potash1 #bcc4 ,soda1 #bcc4 ,skin1 #bah4 ,soda1 carbonate of1 #bcb4 ,nitrate of1 #bbi1 #bfj4 ,salts1 #bca4 ,silicate of1 #bcc4 ,sodium1 chloride of1 #bcb4 ,soil1 the1 #bj1 #hc4 ,influence on the composition of the ash of plants1 #ga4 ,chemical composition of1 #ih4 ,chemical and physical characters of1 #hc4 ,improvement of1 by mechanical means1 #acg4 ,soil1 relation of1 to heat and moisture1 #abg4 ,soils1 absorbent action of1 #abb4 ,air in the pores of1 #aad4 ,analysis1 #aja1 #aah4 ,barrenness of1 #aji4 ,classification of1 #ace4 ,exhaustion of1 #ha4 ,inorganic constituents of1 #he4 ,mixing of1 #aej4 ,origin of1 #hd4 ,organic matters in1 #ajc4 ,physical characters of1 #aah1 #abg4 ,sombrero ,island guano1 #bcf4 ,starch1 #da4 ,lichen1 #db4 ,stearic acid1 #dg4 ,stearine1 #df4 ,stems of plants1 ash in1 #fd4 ,straw1 amount of ash in1 #fd4 ,as a manure1 #aig4 ,sulphate of iron1 #ahb4 ,lime1 #if1 #bec1 #bfj4 ,magnesia1 #ahb4 ,ammonia1 #bi1 #bbg4 ,potash1 #bca4 ,sulphomuriate of ammonia1 #bbg4 ,sulphur in plants1 #gh4 ,sulphuret of iron1 #ace4 ,calcium1 #beb4 ,sulphuretted hydrogen1 #ai4 ,sugar1 #dc4 ,of milk1 #bhc4 ,subsoil1 the1 #acd4 ,ploughing1 #adc4 ,sunflower cake1 #bhf4 ,syenite1 #ia4 ,tares1 #bhf4 ,teelcake1 #bhf4 ,temperature1 influence of1 on germination1 #ed4 ,thomsonite1 #ij4 ,trap rock1 #ib4 ,tubers1 amount of ash in1 #fe4 ,ulmic acid1 #ba4 ,ulmin1 #bb4 ,upper ,peruvian guano1 #bjg1 #bac4 ,urate1 #baf4 ,of ammonia1 #bje4 ,urea1 #afh4 ,uric acid1 #afh1 #bje4 ,urine1 composition of1 #afg4 ,human1 #afh4 ,sulphated1 #baf4 ,valuation of manures1 #bee4 ,vegetable manures1 #aie4 ,vegetation1 influence of light on1 #eg4 ,voelcker's analyses of dung1 #agd4 ,warping1 #adh4 ,water1 absorption of1 by plants1 #ce4 ,decomposition of1 by plants1 #fj4 ,exhalation of1 by plants1 #ce4 ,rain1 #ag1 #ah4 ,wax1 #dh4 ,wheat1 #bhf4 ,woods1 amount of ash in1 #fe4 ,woody fibre1 #da4 ,wool1 #bai4 ,zeolites1 #ij4 ,,printed ,,by ,r4 ,,and ,r4 ,,clark1 ,,edinburgh4 ,a ,,catalogue ,,of ,,books ,,published ,,by ,,adam ,,charles ,,black ,,edinburgh ,,adamson 7,,robert74 ,the ,cottage ,garden4 ,second edition fcap4 #hvo1 cloth1 limp1 #as4 ,,alexander 7,,dr4 ,w4 ,l474 ,christian ,thought and ,work2 a series of ,morning ,meditations on ,passages of ,scripture4 ,second edition1 fcap4 #hvo1 price #es4 ,,anderson 7,professor74 ,elements of ,agricultural ,chemistry4 ,crown #hvo1 price #fs4 #f;d4 ,,anderson 7,,rev4 ,,wm41 ,,ll4,d41 ,glasgow74 ,discourses4 ,second series1 second edition1 crown #hvo1 price #fs4 ---- ,regeneration4 ,second edition1 crown #hvo1 price #fs4 ,,anderson 7,,rev4 ,,james74 ,light in ,darkness1 or ,comfort to the ,sick and ,afflicted1 being a series of ,meditations and ,prayers1 and portions of ,scripture for those visited with bereavement and distress4 ,second edition1 fcap41 cloth1 antique1 red edges1 price #bs4 #f;d4 ,,apperley 7,,charles74 ,the ,horse and the ,hound2 their various ,uses and ,treatment1 including ,practical ,instructions in ,horsemanship and ,hunting1 c41 c4 ,third edition1 with numerous ,illustrations on ,wood and ,steel1 after drawings by ,herring1 ,alken and ,harrison ,weir4 ,post #hvo1 price #ajs4 #f;d4 ,,balfour 7,professor74 ,a ,class-,book of ,botany3 being an ,introduction to the ,study of the ,vegetable ,kingdom4 ,in one large vol4 demy #hvo1 with #ahjj ,illustrations1 #cas4 #f;d4 ,sold also in ,two ,parts3-- ,part ,i4 ,structural and ,morphological ,botany1 #ajs4 #f;d4 ,part ,,ii4 ,vegetable ,physiology1 ,classification ,glossary1 c41 #bas4 ,,balfour 7,professor74 ,a ,manual of ,botany3 being an ,introduction to the ,study of the ,structure1 ,physiology1 and ,classification of ,plants4 ,crown #hvo1 pp4 #gjj1 with #hbj ,illustrations1 price #abs4 #f;d4 ---- ,outlines of ,botany4 ,second edition1 revised and enlarged1 designed for ,schools and ,colleges1 illustrated with nearly #fjj wood-cuts1 pp4 #gab1 fcap4 #hvo1 cloth1 price #hs4 #f;d4 ---- ,the ,botanist's ,companion3 or1 ,directions for the ,use of the ,microscope1 and for the ,collection and ,preservation of ,plants with a ,glossary of ,botanical ,terms4 ,crown #hvo1 price #bs4 #f;d4 ---- ,botany and ,religion2 or1 ,illustrations of the ,works of ,god in the ,structure1 ,functions1 ,arrangement1 and ,general ,distribution of ,plants4 ,third edition1 #bfj ,wood ,engravings1 #abmo1 cloth1 price #fs4 #f;d42 or cloth1 gilt edges1 price #gs4 ,,beesly 7,rev4 ,e4 ,s471 and ,,reynolds 7,rev4 ,s4 ,h47 ,system of ,history for the use of ,students4 ,by ,rev4 ,e4 ,s4 ,,beesly ,m4,a41 late of ,wadham ,college1 ,oxford1 ,professor of ,history1 ,university ,college1 ,london2 and ,,rev4 ,s4 ,h4 ,,reynolds1 ,brazenose ,college1 ,oxford4 ,in preparation4 ,,begbie 7,,james1 ,m4,d47 ,contributions to ,practical ,medicine4 ,contents--,on ,gout2 on ,rheumatism and ,chorea2 on the ,connection of ,erythema ,nodosum with the ,rheumatic ,diathesis2 on ,anaemia and its ,consequences2 on ,dyspepsia and ,nervous ,disorder2 on ,fatty ,degeneration of the ,heart2 on ,erysipelas2 on ,diphtheria and its ,sequels2 on the ,physiological and ,therapeutical ,effects of ,arsenic2 on the ,sedative ,powers of the ,datura ,stramonii ,demy #hvo1 price #ajs4 #f;d4 ,,bennett 7,professor74 ,clinical ,lectures on the ,principles and ,practice of ,medicine4 ,new edition 7the third71 pp4 #ajje1 with five hundred ,illustrations1 price #cjs4 ---- ,an ,introduction to ,clinical ,medicine4 ,six ,lectures on the ,method of ,examining ,patients1 c4 ,fourth edition1 #ajg ,illustrations1 fcap4 #hvo1 price #es4 ---- ,the ,pathology and ,treatment of ,pulmonary ,consumption4 ,second edition1 with #bf large ,illustrations1 demy #hvo1 price #gs4 #f;d4 ,,black',s ,general ,atlas of the ,world4 ,new edition 7#ahfb71 containing #ef maps1 and ,index of #fe1jjj names1 c41 folio1 half-bound morocco1 gilt edges1 price #fjs4 ---- ,school ,atlas4 #dj maps1 and ,index1 #dto or #hvo1 price #ajs4 #f;d4 ---- ,school ,atlas for ,beginners1 #bg maps1 oblong #abn price #bs4 #f;d4 ,,black',s ,atlas of ,australia1 with all the ,gold ,regions1 #f maps1 royal #dto1 price #fs4 ---- ,new ,atlas of ,scotland4 ,a series of #ab ,maps compiled from the best sources1 on the scale of four miles to the inch4 ,imp4 folio1 cloth1 price #cjs4 ---- ,new ,large ,map of ,scotland4 ,scale1 #d miles to the inch1 and measuring when complete #gj by #ef inches4 ,price1 on rollers varnished1 #ebs4 #f;d42 mounted on linen1 in case4 #dbs42 separate sheets coloured1 each1 #bs41 or in cloth cases1 each1 #bs4 #f;d4 ---- ,guide ,books for ,tourists in ,great ,britain and ,ireland1 c4 ---- ,guide to ,london4 ,a ,practical ,guide to the ,metropolis and its ,vicinity4 ,illustrated by a large and accurate ,plan of the ,city--,map of the ,environs--,plans of the ,public ,buildings--,views1 c4 ,in a portable ,volume1 price #ds4 #f;d4 ---- ,new ,plan of ,london4 ,an ,accurate ,guide to the ,streets and ,public ,buildings4 ,in a neat ,case for the ,pocket1 price #as4 ---- ,map of ,environs of ,london4 ,extending from ,windsor to ,gravesend1 ,crystal ,palace1 ,richmond1 ,hampton ,court1 ,epsom1 c4 ,price #as4 ---- ,dorset1 ,devon1 and ,cornwall4 ,with ,maps1 ,plans1 and numerous ,illustrations4 ,price #es4 ---- ,guide to ,yorkshire4 ,new and greatly enlarged ,edition1 illustrated with ,maps1 ,plans1 and ,views4 ,price #es4 ---- ,guide to ,isle of ,wight and ,hampshire4 ,with ,maps1 ,plans1 and ,views4 ,price #bs4 #f;d4 ---- ,guide to ,surrey4 ,including a full ,description of the ,history1 ,antiquities1 and ,topography of the ,county4 ,with ,map and numerous ,illustrations4 ,price #es4 ---- ,guide to ,kent4 ,with ,map and ,numerous ,illustrations4 ,price #cs4 #f;d4 ---- ,guide to ,scotland4 ,new ,edition 7the #aeth7 containing ,map1 and ,one ,hundred ,illustrations4 ,price #hs4 #f;d4 ---- ,guide to ,england4 ,third ,edition1 greatly enlarged and improved1 with ,maps and ,woodcuts4 ,price #ajs4 #f;d4 ---- ,guide to ,english ,lakes4 ,eleventh ,edition1 with ,maps and ,illustrations4 ,price #es4 ---- ,guide to ,wales1 ,north and ,south4 ,eleventh ,edition1 with ,maps and ,charts4 ,price #es4 ---- ,guide to ,ireland4 ,third ,edition1 with ,maps1 ,charts1 and ,views4 ,price #es4 ,,black',s ,guide to ,sussex4 ,with ,map and ,illustrations4 ,price #bs4 #f;d4 ---- ,where ,shall ,we ,go8 ,new ,edition4 ,a ,guide to the ,healthiest and most ,beautiful ,watering ,places in the ,british ,islands4 ,illustrated by ,maps and ,engravings4 ,price #bs4 #f;d4 ---- ,map of ,australia 7size #ci-a_/b by #dj inches74 ,fifth ,edition4 ,containing the ,routes of ,stuart and ,burke1 and the ,latest ,discoveries4 ,price #ajs4 #f;d4 in sheets1 #ads4 in a case folded1 and #b on rollers varnished4 ,this is a magnificent addition to geographical science1 and must supersede all other ,maps having reference to the ,australian ,colonies4-- ,,glasgow ,,daily ,,mail4 ,one of the most perfect specimens which toe have ever met with4-- ,,australian ,,and ,,new ,,zealand ,,gazette4 ,,bromby 7,rev4 ,c4 ,h47 ,church ,students' ,manual4 ,contents--,book of ,common ,prayer--,collects1 ,epistles1 ,collects--,church ,catechism--,confirmation ,service--,history of the ,early ,church--,history of the ,english ,church4 ,fcap #hvo1 red edges1 price #cs4 ,,bruce 7,,james74 ,travels and ,adventures in ,abyssinia4 ,new edition4 ,edited by ,j4 ,m4 ,,clingan1 ,m4,a4 ,five page illustrations and portrait on tinted paper1 by ,c4 ,a4 ,doyle4 ,square #abmo1 cloth1 gilt edges1 price #cs4 #f;d4 ,,bryce 7,,james1 ,m4,a41 ,,ll4,d41 ,glasgow74 ,a ,treatise on ,book-keeping by ,double ,entry1 with an ,appendix on ,single ,entry4 ,fcap4 #hvo1 cloth1 price #es4 ---- ,the ,arithmetic of ,decimals1 adapted to a ,decimal ,coinage4 ,second edition1 price #as4 #f;d4 ---- ,a ,treatise on ,algebra4 ,third edition4 ,crown #hvo1 cloth1 price #fs4 ,,buchan 7,a4 ,w41 ,f4,e4,i4,s47 ,the ,advanced ,prose and ,poetical ,reader2 being a collection of select specimens in ,english1 with ,explanatory ,notes and ,questions on each lesson2 to which are appended ,lists of ,prefixes and ,affixes1 with an ,etymological ,vocabulary4 #abmo1 cloth1 price #cs4 ,,the ,,poetical ,,reader1 separately1 price #as4 #f;d4 ,,burgess 7,rev4 ,,henry1 ,,ll4,d41 etc47 ,the ,amateur ,gardener's ,year ,book1 a ,guide for those who ,cultivate their ,gardens on the ,principles and ,practice of ,horticulture4 ,fcap4 cloth1 price #cs4 #f;d4 ,,candlish 7,rev4 ,dr47 ,life in a ,risen ,saviour4 ,being ,discourses on the ,resurrection4 ,new ,edition 7the third74 ,in preparation4 ,,carson 7,a4 ,r41 ,,ll4,d47 ,exercises in ,attic ,greek for the use of ,schools and ,colleges4 #abmo1 price #ds4 ,,carson 7,a4,r41 ,,ll4,d47 ,phaedrus' ,fables of ,a,esop in ,latin4 ,new edition1 with ,vocabulary1 edited by ,rev4 ,wm4 ,veitch1 #ahmo1 bound1 price #bs4 ,,christison 7,professor74 ,a ,dispensatory4 ,new edition in preparation4 ,,cockburn 7,lord74 ,memorials of ,his ,time4 ,with portrait after ,raeburn4 ,demy #hvo1 price #gs4 #f;d4 ,,cook',s 7,captain7 ,voyages and ,discoveries4 ,edited by ,john ,barrow ,esq41 ,f4,r4,s4 ,illustrated1 square #abmo1 gilt edges1 price #es4 ,,crampton 7,rev4 ,,josiah74 ,the ,lunar ,world1 its ,scenery1 ,motions1 etc4 ,principal ,contents3 ,flight through ,space--,appearance of the ,moon on approaching her--,lunar ,scenery--,wanderings in the ,mare ,imbrium--,mountains--,volcanoes--,motio ns--,utility and ,beauty of the ,moon--,habitability of the ,moon and ,plurality of ,worlds1 etc4 etc4 etc4 ,fourth ,thousand1 fcap4 #hvo1 cloth1 price #cs4 #f;d4 ,,davidson 7,rev4 ,dr47 ,on ,biblical ,criticism4 #hvo1 price #ahs4 ,,demaus 7,rev4 ,,robert1 ,m4,a47 ,class ,book of ,english ,prose1 ,comprehending ,specimens of the most ,distinguished ,prose ,writers from ,,chaucer to the ,present ,time1 with ,biographical ,notices1 ,explanatory ,notes1 and ,introductory ,sketches of the ,history of ,english ,literature4 #abmo1 cloth1 price #ds4 #f;d4 ,or in ,two ,parts1 price #bs4 #f;d4 each4 ---- ,introduction to the ,history of ,english ,literature4 #ab mo1 price #bs4 ---- ,elementary ,reading ,book4 ,illustrated1 #ahmo1 cloth1 price #as4 ---- ,scripture ,class ,book4 ,in the ,press4 ,,denison 7,e4 ,b41 ,m4,a41 ,q4,c47 ,clocks and ,locks4 ,fcap4 #hvo1 price #cs4 #f;d4 ,,de ,,quincey',s 7,,thomas7 ,works4 ,new ,edition4 ,in #ae volumes crown #hvo1 price #ds4 #f;d4 each4 7,see page #ad47 ,,de ,,quincey 7,,thos47 on ,style and ,conversation4 ,a ,series of ,essays4 ,fcap #hvo1 cloth1 price #es4 ,,dick 7,,william74 ,manual of ,veterinary ,science4 ,second ,edition4 #ab mo1 price #es4 ,,donaldson 7,,james1 ,m4,a47 ,latin ,reader of ,jacobs and ,classen4 ,with ,notes1 etc41 #abmo1 price #cs4 #f;d4 ,or ,,course ,i41 price #as4 #i;d4 ,,course ,,ii41 price #bs4 ---- ,modern ,greek ,grammar1 #ab mo1 price #bs4 ,,dresser4 7,professor74 ,popular ,manual of ,botany without technical terms4 ,fcap4 #hvo1 twelve page ,wood ,illustrations1 coloured1 price #ds4 #f;d4 ,,edwards 7,a4 ,m47 ,the ,ambulance ,surgeon2 or1 ,practical ,observations on ,gunshot ,wounds4 ,by ,p4 ,l4 ,,appia4 ,edited1 with ,notes1 by ,t4 ,w4 ,,nunn1 ,f4,r4,c4,s41 ,surgeon to the ,middlesex ,hospital2 and ,a4 ,m4 ,,edwards1 ,lecturer on ,surgery in the ,edinburgh ,medical ,school4 ,fcap4 #hvo4 ,price #fs4 ,,encyclopaedia ,,britannica4 #ba vols41 #dto 7each vol4 #bds41 cloth74 ,complete1 with ,index1 ,l#be3 #abs4 ---- #ba vols1 #dto1 half bound1 ,russia extra1 marbled edges1 #cjs4 per vol41 ,complete ,l#ca3 #ajs42 with ,index ,l#cb3 #b3 #f4 ---- ,index to ,ditto1 #dto1 price #hs41 cloth2 or #abs4 #f;d4 half russia4 ,,fairbairn 7,,william74 ,iron3 its ,history1 ,properties1 and ,processes of ,manufacture4 ,crown #hvo1 price #fs4 ,,farrar 7,,rev4 ,f4 ,w47 ,julian ,home3 ,a ,tale of ,college ,life4 ,foolscap #hvo1 second edition1 price #es4 ---- ,eric2 or ,little by ,little2 a ,tale of ,roslyn ,school4 ,sixth edition1 illustrated1 fcap4 #hvo1 price #es4 ---- ,st4 ,winifred's2 or ,the ,world of ,school4 ,fcap4 #hvo1 cloth1 price #fs4 #f;d4 ,,forbes 7,professor ,j4 ,d47 ,occasional ,papers on the ,theory of ,glaciers1 with ten ,plates and twenty-nine ,wood ,engravings4 ,demy #hvo1 price #ajs4 #f;d4 ---- ,norway and its ,glaciers4 ,followed by ,journals of ,excursions in the ,high ,alps of ,dauphine1 ,berne1 and ,savoy4 ,with two ,maps1 ten ,coloured ,lithographic ,views1 and twenty-two ,wood ,engravings4 ,royal #hvo1 price #bas4 ,,forbes 7,professor ,j4 ,d47 ,tour of ,mont ,blanc and of ,monte ,rosa4 ,illustrated with ,map of the ,pennine ,chain of ,alps1 fcap4 #hvo4 price #cs4 #f;d4 ,,graham 7,g4 ,f47 ,musical ,composition3 its ,theory and ,practice4 ,with numerous ,engravings1 and copious ,musical ,illustrations4 #dto1 price #is4 ,,gulliver',s ,travels to ,liliput4 ,illustrated4 ,fcap4 #hvo1 gilt edges1 price #as4 #f;d4 ,,gunn 7,,wm4 ,m41 ,,ll4,d47 ,rudiments of the ,latin ,language4 #abmo1 price #bs4 ,,guthrie 7,rev4 ,dr47 ,pleas for ,ragged ,schools4 ,seventh ,thousand4 ,crown #hvo4 ,illustrated cover4 ,price #as4 ---- ,the ,gospel in ,ezekiel4 ,twenty-seventh thousand4 ,crown #hvo1 price #gs4 #f;d4 ---- ,christ and the ,inheritance of the ,saints4 ,sixteenth thousand4 ,crown #hvo1 price #gs4 #f;d4 ---- ,the ,way to ,life4 ,seventh thousand4 ,fcap4 #hvo1 price #es4 ---- ,the ,christian ,world ,unmasked1 by ,,berridge4 ,edited by ,,dr4 ,,guthrie4 ,fcap4 #hvo1 cloth antique1 red edges1 price #bs4 #f;d4 ---- ,the ,street ,preacher1 being the ,autobiography of ,robert ,flockhart4 ,edited by ,,dr4 ,,guthrie4 ,small crown #hvo1 cloth limp price #bs4 ,,hampden 7,r4 ,d47 ,the ,fathers of ,greek ,philosophy4 ,demy #hvo1 price #afs4 ,,herschel 7,sir ,j4 ,f4 ,w41 ,bart47 ,physical ,geography4 ,second edition1 crown #hvo1 price #gs4 #f;d4 ---- ,meteorology4 ,fcap4 #hvo1 price #es4 ---- ,the ,telescope4 ,fcap4 #hvo1 price #cs4 #f;d4 ,,jeffrey 7,rev4 ,dr47 ,voices from ,calvary2 or the ,seven ,last ,sayings of ,our ,dying ,lord4 ,second edition1 fcap4 #hvo1 cloth antique1 price #ds4 ,,jukes 7,j4 ,b47 ,the ,student's ,manual of ,geology4 ,new and greatly enlarged ,edition1 with ,lists and ,figures of characteristic ,fossils1 and containing upwards of ,four ,hundred ,wood ,engravings4 ,crown #hvo1 pp4 #gej1 price #abs4 #f;d4 ,,jukes 7,j4 ,b47 ,school ,boy's ,manual of ,geology4 ,in preparation4 ,,kelland 7,professor74 ,elements of ,algebra1 for the use of ,schools and ,junior ,classes in ,colleges4 ,crown #hvo1 price #ds4 ---- ,algebra--being a ,complete and easy ,introduction to ,analytical ,science4 ,crown #hvo1 pp4 #dfg1 price #gs4 #f;d4 ,,kemp 7,w4 ,s41 ,m4,a47 ,a ,course of ,exercises in ,latin ,prose ,syntax4 ,crown #hvo1 price #cs4 #f;d42 or in two ,parts1--,part ,i4 ,agreement and ,government1 #bs4 ,part ,,ii4 ,the ,syntax of the ,subjunctive ,mood1 #bs4 ,part ,,iii4 ,introductory1 #aj;d4 ,,kitto 7,dr47 ,new ,edition of ,kitto's ,cyclopaedia of ,biblical ,literature4 ,edited by ,,william ,,lindsay ,,alexander1 ,d4,d41 assisted by numerous ,contributors4 ,now publishing in ,monthly ,parts1 super-royal #hvo1 price #bs4 #f;d4 each1 illustrated with numerous ,engravings on ,wood and ,steel4 ---- ,popular ,cyclopaedia of ,biblical ,literature4 ,in one volume1 #hvo1 illustrated by #ccf ,engravings1 price #ajs4 #f;d4 ---- ,history of ,palestine2 from the ,patriarchal ,age to the present time4 ,numerous ,wood ,engravings1 crown #hvo1 price #es4 ---- ,school ,edition4 #abmo1 price #ds42 without ,map1 #cs4 #f;d4 ,,lamartine 7,,alphonse ,,de74 ,mary ,stuart4 ,with ,portrait1 crown #hvo1 price #es4 ,,lockhart 7,j47 ,school ,geography for the ,use of ,junior ,pupils in ,mixed ,schools4 #abmo1 price #as4 ,m',,culloch 7,j4 ,r47 ,principles of ,political ,economy4 #hvo1 price #aes4 ---- ,a ,treatise on ,metallic and ,paper ,money and ,banks1 written for the ,encyclopaedia ,britannica4 #dto1 #es4 ---- ,economical ,policy4 ,second edition1 enlarged and improved1 #hvo1 price #ajs4 #f;d4 ---- ,on ,taxation4 #dto1 price #cs4 #f;d4 ,,macaulay 7,lord74 ,biographies of ,atterbury1 ,bunyan1 ,goldsmith1 ,johnson1 and ,pitt1 contributed to the ,encyclopaedia ,britannica4 ,eleventh thousand4 ,fcap4 #hvo1 with ,portrait by ,maull and ,polyblank1 price #cs4 #f;d4 ,,macaulay 7,dr4 ,,alexr47 ,medical ,dictionary1 designed for popular use2 containing an account of ,diseases and their ,treatment1 including those most frequent in warm climates4 ,new edition1 greatly enlarged and improved4 ,by ,,robert ,,welbank ,,macaulay1 ,m4,d41 ,h4,e4,i4,c4,s4 ,demy #hvo1 price #ajs4 #f;d4 cloth1 and #abs4 #f;d4 half-russia4 ,,mansel 7,h4 ,l41 ,d4,c4,l47 ,metaphysics1 or the ,philosophy of ,consciousness4 ,crown #hvo1 price #gs4 #f;d4 ,,masson 7,,gustave74 ,introduction to the ,history of ,french ,literature4 #abmo1 cloth1 #bs4 #f;d4 ---- ,class-,book of ,french ,literature1 with ,biographical ,notices1 ,notes and ,chronological ,tables1 crown #hvo1 price #ds4 #f;d4 ,,miller',s 7,,hugh7 ,works1 crown #hvo1 each #gs4 #f;d4 99 ,,my ,,schools ,,and ,,schoolmasters4 #aa1jjj4 ,,scenes ,,and ,,legends ,,in ,,the ,,north ,,of ,,scotland4 #f1jjj4 99 ,,first ,,impressions ,,of ,,england ,,and ,,its ,,people4 #g1jjj4 ,,the ,,old ,,red ,,sandstone4 #aj1jjj4 ,,testimony ,,of ,,the ,,rocks4 #bi1jjj4 ,,the ,,cruise ,,of ,,the ,,betsy4 #d1jjj4 ,,sketch ,,book ,,of ,,popular ,,geology4 #b1jjj4 ,,foot-,,prints ,,of ,,the ,,creator4 #g1jjj4 ,,essays1 ,,historical ,,and ,,critical4 #b1jjj4 ,,the ,,headship ,,of ,,christ4 #b1jjj4 ,,essays1 ,,historical1 ,,biographical1 ,,and ,,critical4 #b1jjj4 ,,tales ,,and ,,sketches4 ----99 ,cheap editions of the above1 crown #hvo1 cloth1 limp1 price #bs4 #f;d4 ,,miller 7,professor74 ,principles and ,practice of ,surgery4 ,numerous ,illustrations4 ,new edition4 ,in the press4 ,,munchausen 7,baron74 ,numerous ,illustrations4 #ahmo1 gilt edges1 price #as4 #f;d4 ,,murray 7,,andrew ,,and ,,robert74 ,shipbuilding in ,iron and ,wood4 ,new ,edition4 ,illustrated with ,plates and ,woodcuts1 #dto1 price #ads4 ,,neill 7,,patrick1 ,,ll4,d47 ,the ,fruit1 ,flower1 and ,kitchen ,garden4 ,profusely ,illustrated4 ,fcap4 #hvo1 price #cs4 #f;d4 ,,nicol 7,professor74 ,elements of ,mineralogy2 containing a ,general ,introduction to the ,science1 with descriptions of the ,species4 ,fcap4 #hvo1 price #es4 ,,oswald 7,rev4 ,,john74 ,etymological ,dictionary of the ,english ,language4 ,seventh edition1 #ahmo1 bound1 #es4 ,,owen 7,,richard1 ,f4,r4,s47 ,palaeontology1 or a ,systematic ,summary of ,extinct ,animals1 and their ,geological ,relations4 #ada ,illustrations1 second edition1 demy #hvo1 price #afs4 ,,park 7,,mungo74 ,travels in ,africa4 ,nine page ,illustrations1 square #abmo1 gilt edges1 price #cs4 #f;d4 ,,paterson 7,,james1 ,m4,a41 ,barrister at ,law74 ,compendium of ,english and ,scotch ,law4 ,royal #hvo1 price #bhs4 ,,pillans 7,professor74 ,eclogae ,ciceronianae4 #ahmo1 price #cs4 #f;d4 ---- ,first ,steps in ,physical and ,classical ,geography4 ,fcap4 #hvo1 price #as4 #f;d4 ,,porteous 7,bishop74 ,evidences of the ,truth1 and ,divine ,origin of the ,christian ,revelation1 with ,definitions and ,analysis by ,,james ,,boyd1 ,,ll4,d4 #ahmo1 price #as4 ,,poetry and ,poets of ,britain4 ,from ,chaucer to ,tennyson1 with ,biographical ,sketches1 and a rapid ,view of the ,characteristic ,attributes of each4 ,by ,,daniel ,,scrymgeour4 ,post #hvo1 gilt edges1 price #gs4 #f;d4 ,,poets and ,prose ,writers of ,france1 from the ,earliest ,period to the ,beginning of the ,present ,century4 ,by ,,gustave ,,masson1 ,b4,a41 c41 ,assistant ,master at ,harrow ,school4 ,crown #hvo1 pp4 #eag cloth1 gilt edges1 price #gs4 #f;d4 ,,prose and ,prose ,writers of ,britain4 ,by ,rev4 ,,robert ,,demaus1 ,m4,a4 ,crown #hvo1 gilt edges1 price #gs4 #f;d4 ,,ramsay 7,,allan74 ,the ,gentle ,shepherd4 ,illustrated1 #afmo1 price #bs4 #f;d42 gilt edges #cs4 ,,richardson 7,,sir ,,john1 ,,ll4,d41 etc47 ,the ,polar regions4 ,demy #hvo4 ,with ,map1 price #ads4 ,,robinson ,,crusoe4 ,illustrated by ,c4 ,a4 ,doyle4 ,square #abmo1 gilt edges1 price #cs4 #f;d4 ,,russell 7,,scott74 ,the ,steam ,engine4 ,illustrated1 post #hvo1 price #es4 ,,russel 7,,scott74 ,steam and ,steam ,navigation4 ,a ,treatise on the ,nature1 ,properties1 and ,applications of ,steam1 and on ,steam ,navigation4 ,illustrated1 post #hvo1 #is4 ,,schmitz 7,dr47 ,elementary ,greek ,grammar4 #abmo1 price #cs4 #f;d4 ,,scrymgeour 7,,daniel74 ,class-,book of ,english ,poetry4 #abmo1 price #ds4 #f;d4 ,or in #b parts1 price #bs4 #f;d4 each4 ,,scott 7,sir ,,walter74 ,complete ,works and ,life4 #ih vols41 fcap4 #hvo1 ,l#ad3 #ad4 ---- ,waverley ,novels4 ,the latest editions with the ,author's ,notes-- ,,new ,,illustrated ,,edition of #ahfj1 #dh vols41 fcap4 #hvo1 cloth1 #if ,plates1 and #agjj ,illustrations ,l#aj #aj #j ,,library ,,edition1 #be vols4 demy #hvo1 with #bjd ,engravings after ,wilkie1 ,landseer #ab #ab #j ,,author',s ,,favourite ,,edition of #ahdg1 in #dh vols41 fcap4 #hvo1 with ,frontispiece and ,vignette to each vol4 #g #d #j ,,cabinet ,,edition1 #be vols41 fcap #hvo1 each vol4 containing ,steel ,frontispiece and ,woodcut ,vignette #c #aj #j ,,people',s ,,edition1 #e vols4 royal #hvo1 with ,illustrations #b #b #j ,,railway ,,edition1 #be vols41 fcap4 #hvo1 ,illustrated ,covers #a #ag #f ,separately1 #as4 #f;d4 each1 or in cloth1 #bs4 ,vol4 #a ,waverley1 or ',tis ,sixty ,years ,since4 #b4 ,guy ,mannering1 or ,the ,astrologer4 #c4 ,antiquary #d4 ,rob ,roy4 #e4 ,old ,mortality4 #f4 ,black ,dwarf1 and ,legend of ,montrose4 #g4 ,heart of ,mid-,lothian4 #h4 ,bride of ,lammermoor4 #i4 ,ivanhoe4 #aj4 ,monastery4 #aa4 ,abbott4 #ab4 ,kenilworth4 #ac4 ,pirate4 #ad4 ,fortunes of ,nigel4 #ae4 ,peveril of the ,peak4 #af4 ,quentin ,durward4 #ag4 ,st4 ,ronan's ,well4 #ah4 ,redgauntlet4 #ai4 ,the ,betrothed4 #bj4 ,the ,talisman4 #ba4 ,woodstock4 #bb4 ,fair ,maid of ,perth4 #bc4 ,anne of ,geierstein1 or the ,maiden of the ,mist4 #bd4 ,count ,robert of ,paris4 #be4 ,surgeon's ,daughter--,castle ,dangerous4 ---- ,poetical ,works4 ,various editions1 from #es4 to #cfs4 ,,scott 7,sir ,,walter74 ,miscellaneous ,prose ,works4 ,various editions1 from #bfs4 to #hds4 ---- ,life of ,napoleon ,bonaparte4 #e vols41 fcap4 #hvo1 price #bjs4 ,people's edition1 #a vol41 royal #hvo1 price #ajs4 ---- ,tales of a ,grandfather4 ,various editions1 #fs4 to #aes4 ---- ,beauties of4 ,crown #hvo1 gilt edges1 price #cs4 #f;d4 ---- ,life of1 by ,j4 ,g4 ,lockhart4 ,various editions1 #gs4 #f;d4 to #cjs4 ,,simpson 7,professor74 ,obstetric ,memoirs and ,contributions1 including those on ,anaesthesia4 ,edited by ,c4 ,w4 ,priestly1 ,m4,d41 and ,h4 ,r4 ,storer1 ,m4,d4 #b vols4 #hvo1 profusely ,illustrated1 #cfs4 ---- ,,on ,,the ,,diseases ,,of ,,women4 #hvo4 ,in preparation4 ,,smith 7,,adam1 ,,ll4,d47 ,the ,wealth of ,nations3 an ,inquiry into the ,nature and ,causes of the ,wealth of ,nations4 ,edited1 and with ,life of the ,author1 by ,j4 ,r4 ,m',,culloch1 ,esq4 ,fourth edition1 corrected throughout1 and greatly enlarged4 #hvo1 #afs4 ,,spalding 7,,wm41 ,m4,a47 ,an ,introduction to ,logical ,science4 ,fcap4 #hvo1 #ds4 #f;d4 ,,stevenson 7,,david74 ,canal and ,river ,engineering4 ,small #hvo1 #ds4 #f;d4 ,,stevenson 7,,thomas74 ,on ,harbours4 ,crown #hvo4 ,in the ,press4 ,,stewart 7,w4 ,c47 ,the ,practical ,angler1 or the ,art of ,trout ,fishing1 more particularly applied to ,clear ,water4 ,fourth edition1 #abmo1 cloth1 price #cs4 #f;d4 ,,thomas 7,dr4 ,,robert74 ,the ,modern ,practice of ,physic4 ,eleventh edition1 edited by ,dr4 ,frampton4 #b vols4 #hvo1 price #bhs4 ,,thomson 7,professor74 ,brewing and ,distillation4 ,post #hvo1 price #fs4 ,,traill 7,professor74 ,medical ,jurisprudence4 ,third ,edition1 post #hvo1 price #es4 ,,trail 7,rev4 ,w47 ,the ,literary ,characteristics and ,achievements of the ,bible4 ,crown #hvo4 ,,tytler 7,p4 ,f47 ,history of ,scotland4 ,enlarged and continued to the ,present ,time1 by the ,rev4 ,,james ,,taylor1 ,d4,d41 and adapted to the purposes of ,tuition by ,,alex4 ,,reid1 ,,ll4,d4 ,sixth edition1 #abmo1 #cs4 #f;d4 ---- ,outlines of ,modern ,history4 ,fifth edition1 #abmo1 #cs4 ---- ,outlines of ,ancient ,history4 ,fourth edition1 #abmo1 #cs4 ,,veitch 7,rev4 ,,wm47 ,greek ,verbs1 ,irregular and ,defective4 ,post #hvo1 price #fs4 ,,walpole 7,,horace74 ,the ,castle of ,otranto4 ,fcap4 #hvo1 ,illustrated1 gilt edges1 price #bs4 #f;d4 ,,wardlaw 7,dr47 ,systematic ,theology4 ,a ,complete ,system of ,polemic ,divinity4 ,in three vols41 demy #hvo1 price #bas4 ,,westgarth 7,,william74 ,australia2 its ,rise1 ,progress1 and ,present ,condition2 with ,map4 ,fcap4 #hvo1 price #cs4 #f;d4 ,,whewell 7,dr47 ,new ,edition of ,mackintosh's ,ethical ,philosophy4 ,demy #hvo4 ,price #ajs4 #f;d4 ,,white 7,,robert74 ,madeira2 its ,climate and ,scenery4 ,second edition by ,j4 ,y4 ,,johnson4 ,with numerous ,illustrations1 and a ,map of the ,island1 crown #hvo1 price #gs4 #f;d4 ,,wilson 7,,john74 ,british ,farming1 a description of the mixed husbandry of ,great ,britain4 ,pp4 #efi1 profusely illustrated4 ,demy #hvo1 price #abs4 ,,young 7,,andrew74 ,the ,angler and ,tourist's ,guide to the ,northern ,counties of ,scotland1 with ,instructions to ,young ,anglers4 #ahmo1 price #bs4 ,,de ,,quincey',s ,,works4 ,,author',s ,,edition4 ,in ,fifteen ,volumes1 price #ds4 #f;d4 each1 ,,new ,,edition ,,of ,,the ,,works ,,of ,,thomas ,,de ,,quincey ,,the ,,english ,,opium ,,eater 99 99 99 99 99 ,vol4 ,i4 ,,confessions ,,of ,,an ,,english ,,opium-,,eater4 ,,ii4 ,,recollections ,,of ,,the ,,lake ,,poets4 ,,iii4 ,,last ,,days ,,of ,,immanuel ,,kant4 ,,iv4 ,,the ,,english ,,mail-,,coach4 ,v4 ,,dr4 ,,samuel ,,parr1 ,,etc4 ,,vi4 ,,richard ,,bentley1 ,,etc4 ,,vii4 ,,protestantism ,,and ,,other ,,essays4 ,,viii4 ,,leaders ,,in ,,literature4 ,,ix4 ,,the ,,caesars1 ,,and ,,other ,,writings4 ,x4 ,,rhetoric ,,and ,,style4 ,,xi4 ,,coleridge ,,and ,,opium ,,eating4 ,,xii4 ,,speculations1 ,,literary ,,and ,,philosophic4 ,,xiii4 ,,conversation1 ,,and ,,other ,,papers4 ,,xiv4 ,,the ,,autobiographic ,,sketches--#agij-ahjc4 ,volume ,,xiv4 concludes the series of ,mr4 ,de ,quincey's ,works1 as arranged by himself2 but in order to render this ,edition complete1 a ,,supplementary ,,volume 7,,xv47 will be added1 containing the ,biographies of ,,shakspeare1 ,,pope1 ,,goethe1 and ,,schiller1 contributed by ,mr4 ,de ,quincey to the ,encyclopaedia ,britannica1 and not included in the last ,edition of his ,works1 and a paper1 hitherto unpublished1 on the ,,political ,,parties ,,of ,,modern ,,england4 ,also a ,complete ,,general ,,index to the whole ,works4 99 99 99 99 99 ,,edinburgh3 ,,adam ,,and ,,charles ,,black ,,new ,,edition ,,of ,,kitto',s ,,cyclopaedia4 ,in royal #hvo1 ,volume ,i4 7,a to ,e71 pp4 #hhd4 ,price ,l#a3 #j3 #j4 ,a ,,third ,,edition ,,of ,,kitto',s ,cyclopaedia of ,biblical ,literature4 ,edited by the ,rev4 ,,william ,,lindsay ,,alexander1 ,d4,d41 with the assistance of numerous contributors4 ,illustrated by ,numerous ,engravings on ,wood and ,steel4 ,in undertaking the ,new ,edition of this work1 it was the intention of the ,publishers to complete it in two volumes1 but the additions have been so extensive as to render a third volume necessary4 ,although this change will occasion great extra expense to the ,publishers1 there will be no additional charge to ,subscribers1 who will receive the complete book at ,l#c1 the price to which the ,publishers pledged themselves in their prospectus4 ,list of ,contributors4 ,beard1 ,j4 ,r41 ,d4,d4 ,bell1 ,g4 ,m4 ,brown1 ,john1 ,d4,d41 late ,professor of ,exegetical ,theology to the ,united ,presbyterian ,church of ,scotland4 ,browne1 ,henry1 ,m4,a41 ,vicar of ,pevensey4 ,cairns1 ,john1 ,d4,d4 ,candlish1 ,james ,s41 ,m4,a4 ,credner1 ,karl ,august1 ,d4,d41 late ,professor of ,theology at ,giessen4 ,davidson1 ,samuel1 ,d4,d41 ,,ll4,d4 ,denham1 ,joshua ,fred41 ,m4,a41 ,f4,r4,s4 ,deutsch1 ,emanuel1 of the ,university of ,berlin1 ,m4 ,ger4 ,or4 ,soc41 etc41 ,british ,museum4 ,doran1 ,john ,william1 ,,ll4,d41 ,rector of ,beeston1 ,st4 ,lawrence1 ,norfolk4 ,farrar1 ,frederic ,w41 ,m4,a41 late ,fellow of ,trinity ,college1 ,cambridge4 ,geikie1 ,archibald1 ,f4,r4,s4,e41 ,f4,g4,s41 of the ,geological ,survey4 ,ginsburg1 ,christian ,d4 ,goold1 ,william ,henry1 ,d4,d41 ,professor of ,theology to the ,reformed ,presbyterian ,church4 ,gotch1 ,f4 ,w41 ,d4,d41 ,president of the ,baptist ,college1 ,bristol2 ,examiner in ,hebrew to the ,london ,university4 ,gowan1 ,anthony ,t41 ,d4,d4 ,haevernick1 ,heinrich ,august ,christ41 late ,professor of ,theology at ,koenigsberg4 ,holmes1 ,peter1 ,d4,d41 ,f4,r4,a4,s41 of ,magdalen ,hall1 ,oxford4 ,jamieson1 ,robert1 ,d4,d41 ,minister of ,st4 ,paul's1 ,glasgow4 ,jennings1 ,isaac4 ,kitto1 ,john1 ,d4,d41 ,f4,a4,s4 ,leathes1 ,stanley1 ,m4,a4 ,lyon1 ,william ,p41 ,b4,a4 ,m',causland1 ,dominick1 ,q4,c41 ,,ll4,d4 ,madden1 ,fred4 ,w41 ,m4,r4,s4,l41 ,brit4 ,museum4 ,michelson1 ,e41 ,ph4 ,d4 of the ,university of ,heidelberg4 ,morren1 ,nathanael1 ,m4,a4 ,newman1 ,francis ,w41 late ,fellow of ,balliol ,college1 ,oxford2 ,professor of ,latin in the ,university of ,london4 ,newth1 ,samuel1 ,m4,a41 ,professor1 ,new ,college1 ,london4 ,nicholson1 ,john1 ,b4,a4 ,oxford2 ,ph4 ,d4 ,tuebingen4 ,nicholson1 ,w4 ,a41 ,m4,d4 ,poole1 ,reg4 ,stuart1 ,british ,museum4 ,porter1 ,j4 ,leslie1 ,m4,a41 ,professor of ,sacred ,literature1 ,assembly's ,college1 ,belfast4 ,royle1 ,j4 ,f41 ,m4,d41 ,f4,r4,s41 ,f4,l4,s41 ,f4,g4,s4 ,ryland1 ,j4 ,e4 ,smith1 ,c4 ,hamilton1 ,lieut4-,colonel1 ,k4,h4 and ,k4,w41 ,f4,r4,s41 ,f4,r4,l4,s41 etc4 ,smith1 ,john ,pye1 ,d4,d41 ,f4,r4,s41 ,f4,g4,s4 ,stebbing1 ,henry1 ,d4,d4 of ,st4 ,john's ,college1 ,cambridge4 ,tholuck1 ,august1 ,d4,d41 ,professor of ,theology in the ,university of ,halle4 ,wace1 ,henry1 ,m4,a4 ,wright1 ,william1 ,m4,a4 and ,,ll4,d4 of ,trinity ,college1 ,dublin4 99 99 99 99 99 ,,edinburgh3 ,,adam ,,and ,,charles ,,black4 ,,new ,,edition1 #ahfb4 ,in folio1 half bound morocco1 gilt edges1 price ,l#c1 ,a new edition of ,,black',s ,,general ,,atlas ,,of ,,the ,,world1 ,series of ,fifty-six ,maps1 containing all the ,latest ,discoveries1 beautifully coloured1 and accompanied by an ,alphabetical ,index of #fe1jjj ,names1 forming a ready ,key to the places mentioned in the ,maps4 ,list of ,maps in the order in which they occur4 ,,physical ,,geography1 ,,etc4 #a4 ,the ,world in ,hemispheres1 with ,comparative ,view of ,mountains and ,rivers4 #b4 ,the ,world on ,mercator's ,projection4 #c4 ,physical and ,ethnographical ,charts of the ,world4 #d4 ,zoological and ,botanical ,charts of the ,world4 #e4 ,isothermal ,chart shewing the ,temperature of the ,earth's ,surface4 #f4 ,northern and ,southern ,celestial ,hemisphere4 #g4 ,solar ,system1 ,theory of the ,seasons1 etc4 ,,europe4 #h4 ,europe4 #i4 ,england 7,north ,part74 #aj4 4444444 7,south ,part74 #aa4 ,scotland 7,north ,part74 #ab4 44444444 7,south ,part74 #ac4 ,ireland4 #ad4 ,france4 #ae4 ,switzerland4 #af4 ,holland and ,belgium4 #ag4 ,railway ,map of ,central ,europe4 #ah4 ,germany4 #ai4 ,austria4 #bj4 ,prussia4 #ba4 ,denmark4 #bb4 ,sweden and ,norway1 with ,baltic ,sea4 #bc4 ,russia in ,europe4 #bd4 ,spain and ,portugal4 #be4 ,italy 7,north74 #bf4 44444 7,south74 #bg4 ,turkey in ,europe4 #bh4 ,greece and ,ionian ,islands4 ,,asia4 #bi4 ,asia4 #cj4 ,turkey in ,asia4 #ca4 ,palestine4 #cb4 ,persia1 ,afghanistan1 and ,beloochistan4 #cc4 ,india4 #cd4 ,china4 #ce4 ,indian ,archipelago1 and ,further ,india1 including ,burmah1 ,siam1 etc4 ,,africa4 #cf4 ,africa1 with ,barth's1 ,livingstone's1 and ,burton's ,routes4 #cg4 ,egypt4 #ch4 ,south ,africa4 ,,america4 #ci4 ,north ,america1 with ,enlargement of ,british ,columbia4 #dj4 ,british ,america and ,arctic ,regions4 #da4 ,canada ,east1 ,new ,brunswick1 ,nova ,scotia1 etc4 #db4 ,canada ,west4 #dc4 ,united ,states of ,america 7,general ,map74 #dd4 ,the ,eastern or ,principal ,states4 #de4 ,the ,western ,states 7,california1 ,oregon1 ,utah1 etc47 #df4 ,mexico1 ,central ,america1 etc4 #dg4 ,west ,india ,islands4 #dh4 ,south ,america4 #di4 ,venezuela1 ,new ,granada1 ,equador1 and ,peru4 #ej4 ,chili--,argentine ,republic1 and ,bolivia4 #ea4 ,brazil1 ,uruguay1 and ,guayana4 ,,australia ,,and ,,islands ,,of ,,the ,,pacific4 #eb4 ,australia4 #ec4 ,new ,zealand1 ,tasmania1 and ,western ,australia4 #ed4 ,polynesia and ,pacific ,ocean4 #ee4 ,the ,world as known to the ,ancients4 #ef4 ,the ,principal ,countries of the ,ancient ,world1 with the ,roman and ,persian ,empires4 ,accompanied by ,sketch ,maps of the ,federal and ,confederate ,states1 and of a portion of ,mexico4 99 99 99 99 99 ,,edinburgh3 ,,adam ,,and ,,charles ,,black4