COMPLETE WORKS ON COMPRISING HIS AGRICULTURAL CHEMISTRY, OR ORGANIC CHEMISTRY IN ITS APPLICATION TO AGRICULTURE AND PHYSIOLOGY; ANIMAL CHEMISTRY, OR ORGANIC CHEMISTRY IN ITS APPLICATION TO PHYSIOLOGY AND PATHOLOGY; AND RESEARCHES ON THE MOTION OF THE JUICES OF THE ANIMAL BODY; TOGETHER WITH AN ACCOUNT OF THE ORIGIN OF THE POTATO DISEASE, WITH FULL DIRECTIONS FOR THE PROTECTION AND ENTIRE PREVENTION OF THE POTATO PLANT AGAINST ALL DISEASES. BY JUSTUS LIEBIG, M.D., PH.D., F.R.S., M.R.I.A. PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF GIESSEN; KNIGHT OF THE HESSIAN ORDER, AND OF TtIE IMPERIAL ORDER OF SAINT ANN; MEMBER OF THE ROYAL ACADEMY OF SCIENCES OF STOCKHOLM; CORRESPONDING MEMBER OF THE ROYAL ACADEMIES OF SCIENCES OF BERLIN AND MUNICH; OF THE IMPERIAL ACADEMY OF ST. PETERSBURGH OF THE ROYAL INSTITUTION OF AMSTERDAM, ETC.) ETC. c" Every page contains a mass of information. I would earnestly advise all practical men, and all interested in cultivation, to have recourse to the book itself. The subject is vastly important, and we cannot estimate how much may be added to the produce of our fields by proceeding on correct principles."-Loudon's Gardener's Magazine. " By the perusal of such works as these, the farmer need no longer be groping in the dark, and liable to mistakes; nor would the most unnatural odium of farming by the book be longer existent. " In conclusion, we recommend these works to the agriculturist and to the horticulturist, to the amateur florist, and to the curious student into the mysteries of organic life, assured that they will find matter of interest and of profit in their several tastes and pursuits." —Hovey's Magazine of Horticulture. T. B. PETERSON, NO. 98 CHESTNUT STREET.ia: T. B. PETERSON, NO. 98 CHESTNUT STREET. RESEARCHES ON THE MOTION OF THE JUICES IN THE ANIMAL BODY; AND THE EFFECT OF EVAPORATION IN PLANTS. TOGETHER WITH AN ACCOUNT OF THE ORIGIN OF THE POTATO DISEASE; WITH FULL AND INGENIOUS DIRECTIONS FOR THE PROTECTION AND ENTIRE PREVENTION OF THE POTATO PLANT AGAINST ALL DISEASES. BY JUSTUS LIEBIG, M.D., PH.D., F.R.S., MeR.I.A. PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF GIESSEN. ILLUSTRATED WITH FIFTEEN FINE EEGAVINGS. EDITED FROM THE MANUSCRIPT OF TIEE AUTHOR, BY WILLIAM GREGORY, M. D., PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF EDINBURG. T. B. PETERSONp iNo. 98 HESNUT STREET.: T. B. PETERSON, No. 98 CHESNUT STREET. PREFACE. THE present little work contains a series of experiments the object of which is to ascertain the law according to which the mixture of two liquids, separated by a membrane, takes place. The reader will, I trust, perceive in these researches an effort to attain, experimentally, to a more exact expression of the conditions under which the apparatus of the circulation acquires all the properties of an apparatus of absorption. In the course of this investigation, the more intimate study of the pheDomena of Endosmosis impressed on me the conviction that, in the organism of many classes of animals, causes of the motion of the juices were in operation, far more powerful than that to which the name of Endosmosis has been given. The passage of the digested food through the membranes of the intestinal canal, and its entrance into the blood; the passage of the nutrient fluid outwards from the blood vessels, and its motion towards the parts where its constituents acquire vital properties,-these two fundamental phenomena of organic life cannot be explained by a simple law of mixture. The Experiments described in the following pages will, perhaps, be found to justify the conviction that these organic movements depend on the transpiration and on the atmospheric pressure. The importance of the transpiration for the normal vital process has, indeed, been acknowledged by physicians ever since Medicine had an existence; but the law of the dependance of the state of health on the quality of the atmosphere, on its barometric pressure, and its hygrometric condition, has been hitherto but little investigated. By the researches contained in my examination of the constituents of the juice of flesh, as well as by those described in the present work, the completion of the second part of my Animal Chemistry has been delayed; but I did not consider myself justified in continuing that work until I had examined the questions suggested by,-and connected with those researches, DR. JUSTUS LIEBIG. GIEssEN, February, 1850. (5) EDITOR'S PREFACE. IN the Editor's Preface to Baron Liebig's " Researches on the Chemlstry of Food," in which the Author gave the results of his investigation into the constituents of the juice of the flesh, I mentioned that Baron Liebig had been led to study the subject of Endosmosis experimentally. The results of this investigation are contained in the following pages; and the reader will, I trust, be satisfied that the motions of the animal juices depend on something more than mere Endosmosis or Exosmosis, and that the pressure of the atmosphere, as well as its hygrometric state, by influencing the transpiration from the skin and lungs, are essentially concerned in producing these motions. At the same time, the present work is to be regarded, not as exhausting the subject, but, on the contrary, as only pointing out the direction in which inquiry is likely to lead to the most valuable results. While it is proved that the mechanical causes of pressure and evaporation, and the chemical composition of the fluids and membranes, have a more direct, constant, and essential influence on the motion of the animal fluids, and, consequently, on the state of the health, than has been usually supposed, it is evident that very much remains to be done in tracing that influence under the ever varying circumstances of the animal body, and in applying the knowledge thus acquired to the purposes of hygiene and therapeutics. But it is equally obvious, that the above-mentioned mechanical and chemical causes are not alone sufficient to explain the phenomena of animal life, since they are present equally in a dead and in a living body; so that while every advance in physiology enables us to explain more.facts on chemical and mechanical principles, something always (3) EDITOR S PREFACE. remains, which, for the present, is beyond our reach, and which may forever remain so. However this may be, the facts established in this and in the preceding work of the Author have very materially extended the application of the well-known laws of physics and of chemistry to physiology, and have also furnished a number of the most beautiful instances of that infinitely wise, but exquisitely simple adaptation of means to ends, which characterizes all the works of the omnipotent Creator; but which is no where more admirably displayed, than in the arrangements, imperfectly known as they hitherto are, by which life is maintained. In connection with the Author's remarks on the effects of evaporation in plants, and the consequences of its suppression, and with his opinions as to the origin of the potato disease, I beg to refer the reader to the Appendix for a very ingenious and apparently well founded plan for the protection of the potato plant against the terrible scourge under which it has lately suffered. The views of- Dr. Klotzsch, the author of this plan, as to the nature of the disease, coincide remarkably with those of Baron Liebig, as explained in the present work. WILLIAM GREGORY. ~DInrwuw.T 3d Marce, 185.. CONTENTS. On the phenomena accompanying the mixture of two liquids separated by a membrane................................................................... 9 Relation of porous bodies to water and other liquids.......................... 9 The moistening of porous bodies depends on capillary attraction................ 10 Pressure required to cause liquids to pass through membranes............ 11 The pressure varies with different liquids................................ 11 The absorbent power of the membrane has a share in the effect........11........ 11 Action of brine, oil, alcohol, &c., on moist membranes......................... 12 Cause of the shrivelling of membranes when strewed with salt................. 13 Animal tissues are permeable to all liquids................................... 14 Saline solutions, alcohol, &c., mix with water through membranes.............. 15 Change of volume when two dissimilar liquids mix through a membrane; Endosmosis 15 This change of volume does not depend alone on the different densities.......... 15 Phenomena of the mixture of two liquids through a membrane.................. 16 The mixture is the result of chemical attraction............................ 18 Chemical attraction is every where active..................................... 19 Examples.-Crystallization.............................................. 19 Action of solids on dissolved matters....................................... 19 Laws of the mixture of two dissimilar liquids................................. 21 Effect of the interposition of a membrane.................................... 22 The change of volume in two liquids which mix through a membrane is the result of chemical affinity modifying capillary attraction........................... 23 Effect of evaporation on liquids confined by membranes....................... 24 Views of MAGNUs on Endosmosis........................................... 24 Remarks on his theory....................................... 24 The nature of the membrane has an important influence....................... 25 Unequal attraction of membranes for different liquids.......................... 26 The action of two liquids, separated by a membrane, is equivalent to pressure, unequal on opposite sides........................2..................... 27 Causes which influence the mixture of two liquids separated by a membrane...... 29 These causes produce, in the animal body, absorption of the fluids of the intestines into the blood................................................... 30 Effects of drinking water and saline solutions of different strengths.............. 30 Influence of the cutaneous evaporation on the motion of the animal juices........ 31 (7) 8 CONTENTS. PAGN Experiments....................................................... 32 Influence of the atmospheric pressure................................... 33 Water passes through membranes more easily than air does.................... 34 -Experiments on evaporation through membranes.............................. 34 Importance of the cutaneous transpiration.................................... 35 By it the fluids acquire a motion towards the skin and lungs.................. 35 Effects of dry and moist air, and of elevation, on the health.................... 35 Causes of the efflux of sweat................................................ 36 Fishes die in air, because the due distribution of the fluids is prevented.......... 36 Experiments of HALES on the motion of the sap in plants..................... 36 This motion is caused by evaporation.................................... 37 Force with which the sap rises............................................. 37 The atmospheric pressure is the active force.................................. 38 The sap absorbs gases.................................................... 38 The evaporation supplies food to the plant..................... 38 Influence of suppressed evaporation on hop vines........................... 39 Observations of HALES on the blight in hops, &c............................. 39 Fire-blasts in hops........................................................ 39 HALES recognized the influence of evaporation on the life of plants.............. 39 The origin of the potato disease is probably similar to that of the blight in hops.., 40 The disease long known......................... 40 It is due, not to a degeneration of the plant, but to a combination of external circumstances............................................. 40 It is connected with the weather, and particularly with the temperature and hygrometric state of the atmosphere.......................................... 41 The life of plants is dependent chiefly on four external causes............. 41 Only one of which, namely, the quality of the soil, is in the power of the agriculturist 41 Effects of suppressed evaporation...................... 41 The fungi-and putrefaction follow the death of the plant......................, 41 Observations of HALES on the rise of the spring sap in perennial plants........ 41 Views of DUTROCHET.................42 Objections to these views.................................................. 42 The cause of the rise of the sap is transient, and depends on external influences. 42 It exists, not merely in the spongioles, but in all parts of the plant.......... 42 Experiments of HALES................................................ 43 His conclusions.................................................... 43 Gas is given off by the sap............................ 44 The rise may therefore be due to the disengagement of gas................... 44 The gas is probably carbonic acid.......................................... 44 APPENDIX. Account of a plan proposed by Dr. KLOTZSCH, of Berlin, protecting potato plants from disease............................................... 45 This plan published by authority of the Minister of the Interior of Prussia, on the favorable report of the President of the College of Rural Economy at Berlin... 47 Conditions on which the reward, claimed for his plan, if found effectual, by Dr. KLOTZSCu, has been granted...........................................47 ON THE PHENOMENA ACCOMPANYING THE MIXTURE OF TWO LIQUIDS SEPARATED BY' A MEMBRANE. qtEE constituents of the food, which have assumed a soluble form in the alimentary canal, are thereby endowed with the property of yielding to the influence of every cause which, in acting on them, tends to change their place or the position which they occupy.* They are conveyed into the blood vessels, and from thence are distributed to all. parts of the body. The movement and distribution of these fluids, and of all the substances dissolved in them, exclusive of the mechanical cause 6f the contraction of the heart, by which the circulation of the blood is effected, depend, 1, on the permeability of the walls of all vessels to these fluids; 2, on the pressure of the atmosphere; and 3, on the chemical attraction which the various fluids of the body exert on each other.t The motion of all fluids in the body is effected by means of water: and all parts of the animal system contain, in the normal state, a certain amount of water. Animal membranes, tendons, muscular fibres, cartilaginous ligaments, the yellow ligaments of the- vertebral column, the cornea, transparent and opaque, &c., all contain, in the fresh state, more than half their weight of water, which they lose, more or less completely, in dry air.: On the presence of this water depend several of their physical properties. The fresh, opaque, milk-white cartilagesof the ear become, when dried, translucent, and acquire a reddish yellow color. Tendons, when fresh, are in a high degree flexible and elastic and possess a silky lustre, which they lose when dried. By the same loss of water they become, further, hard, horny, and translucent, and when bent, split into whitish bundles of fibres. The sclerotic coat is milk-white when fresh, and becomes transparent by desiccation. When these substances, after having lost, by drying, a part of the properties which they possess in the fresh state, are again placed in contact with pure water, they take up, in 24 hours, the whole original amount of water, and recover perfectly those properties which they had lost. The opaque cornea, or sclerotic coat, which had become transparent by desiccation, again becomes milk-white, while the transparent cornea, which had been rendered opaque by drying, now becomes again transparent. The tendons,- which, when dried, had become horny, hard, and translucent, now again become flexible and elastic, and recover their silky * The food becomes soluble, and the fluids of the body are sent to all parts. tGeneral causes of their motion. t Relation of animal tissues to water. 2 (9) 1 0 MOTION OF THE JUICES OF THE ANIMAL BODY. lustre. The fibrine and the cartilages of the ear, which desiccation had rendered horny and transparent, again become milk-white and elastic. The power which the solids of the animal body possess of taking up water iIto their substance. and of being penetrable to water, extends to all fluids allied to water, that is miscible with it.* In the dried state, the animal solids take up fluids of the most diverse natures, such as fatty and volatile oils, ether, bisulphuret of carbon, &c. This permeability to fluids is possessed by animal tissues in common with all porous bodies; and no doubt can be entertained, that this property is determined by the same cause which produces the ascent of fluids in narrow tubes, or in the pores of a sponge; phenomena, which we are accustomed to include under the name of capillary action.'One condition, essential to the permeability of porous bodies for fluids (or their power of absorption), is their capability of being moistened; or the attraction which the particles of the fluid and the walls of the pores or tubes have towards each other.t A second condition is the attraction which one particle of the fluid has to another. We have no means of estimating the absolute size of the particles or molecules of a fluid, such as water, but they are certainly infinitely smaller than the measurable diameter of a tube, or of the pores of a porous body. It is obvious, therefore, that in the interior of a capillary tube or pore, filled with a fluid, only a certain number of the fluid molecules are in contact with the walls of the tube, and attracted by them; while in the middle of the tube, and from thence towards its parietes, fluid molecules must exist which only retain their place in virtue of the attraction which the molecules, attracted by the parietes, exert on those not so attracted; that is, by the cohesive, attraction of the fluid. Liquids flow out of capillary tubes, which are filled with them, only when some other force or cause acts, because capillary attraction cannot produce motion beyond the limits of the solid body which determines the capillary action. The penetration of a fluid into the pores of a porous body, is the result of capillary attraction; its expulsion can be affected by a mechanical pressure; and may be accelerated by increasing this pressure, and by all such causes as diminish the mutual attraction of the fluid molecules, or the attraction of the walls of the pores for those molecules. The Condition most favorable to the passage of a fluid through the pores of a porous substance under pressure, is when one fluid molecule can be displaced so as to glide away over another. The slightest pressure suffices to, expel the displaceable particles of water from a sponge; a higher pressure is required to express the same fluid from bibulous paper; and a pressure much higher still is necessary in order to cause water to flow out of moist wood.t We may form some idea of the force with which porous organic substances, such as dry wood, absorb and retain water, if we remember, that by inserting of wedges of dry wood in proper cuts, and subsequently moistening them, rocks may be split and fractured. When -we compare with the properties just enumerated, which belong to all porous bodies, those properties which are observed in animal substances under the same circumstances, it appears plainly that these animal substances have pores in certain directions;~ although these openings are so minute that they are not, in the case of most tissues, perceptible, even with the aid of the best microscopes. It has been mentioned that tendons, ligaments, cartilages, &c., contain, in the fresh state, a certain amount of water, which, according to all experiments made on the subject, is invariable; and that several of their properties depend on the presence of this water.ll (CHEVREUL.) When these substances, wrapped in bibulous paper, are subjected to a powerful pressure, a certain proportion of this water is expelled. Fresh and flexible vessels lose, in this way, 37.6 per cent., and the yellow ligaments of the vertebre lose 35 per cent. of water. This property, namely, that of losing water under pressure, is only found in porous substances. It is obvious that by pressure, that is, by diminution of the size of the pores, only that portion of * The tissues absorb other fluids. f The moistening of porous bodies.:Prodigious force with which porous bodies absorb water. 0 Animal tissues are porous. lAmount of water expelled by pressure from tissues. ABSORBENT POWER OF MEMBRANES. l water can be pressed out which is not retained by chemical attraction.* It is in the highest degree worthy of notice, that this water, not chemically combined, seems to have the greatest share in the properties which these animal substances possess in the fresh state, for the pressed tendons and yellow ligaments become transparent; the former lose their flexibilty, the latter their elasticity; and if laid-in water, they recover these properties perfectly. In the pores of a porous substance, the fluid molecules are retained by two kinds of attraction, namely, by the affinity which is exerted between the walls of the pores and the molecules of the fluid, and by the cohesion which acts between the molecules of the fluid itself. It would appear as if the molecules of water were thus brought into different states, and this seems to be the cause of the differences observed in the properties of these animal substances when they contain different proportions of water. Fig. 1. tif the wide opening of the tube, Fig. 1, be tied over with a portion of bladder, and water poured into the wide part of the tube, as far as the mark a, we shall find that, when mercury is poured into the upright narrow part of the tube, to a certain height, the whole external surface of the bladder becomes covered with minnte drops, which, if the column of mercury be made a few lines higher, unite, so as to form large drops. These continue to flow out uninterruptedly, if mercury be added, so as to keep the column at the same height, till at last the wide part of the tube is emptied of water and filled with mercury. Solution of salt, fat oil, alcohol, &c., behave exactly as water does; under a certain pressure these fluids pass through an animal membrane, just as water does through a paper filter. The pressure required to cause these liquids to flow through the pores of animal textures depends on the thickness of the membrane, as well as on the chemical nature of the different liquids. Through ox-bladder, Coth of a line (lToth of an inch) thick, water flows under a pressure of 12 inches of mercury.1 A saturated solution of sea salt requires from 18 to 20 inches; and oil (marrow oil) only flows out under a pressure of 34 inches of mercury. When the membrane used is the peritoneum of the ox, -oth of a line, ({,-th of an inch) in thickness, water is forced through it by-8 to 10 inches, brine by 12 to 16 inches, oil by' 22 to 24 inches, and alcohol by 36 to 40 inches of mercury. The same membrane from the calf, ath of a line (Tpagd of an inch) in thickness, allows water to pass through under the pressure of a column of water 4 inches high;.brine passes under a pressure of 8 to 10 inches of brine, and oil under a pressure of 3 inches of mercury. In making experiments of this nature, we observe that, after they have continued for some time, the pressure required to force the liquid through the membrane does not continue equal. If during the first 6 hours a pressure of 12 inches of mercury were necessary, we often find that after 24 or 36 hours, 8, or even 6 inches will suffice to produce the same effect, obviously because by long-continued contact with water, the membrane undergoes an alteration, in consequence of which the pores are widened. From these experiments it appears, that the power of a liquid to filter through an animal membrane bears no relation to the mobility of its particles;~ for under a pressure which causes water, brine, or oil to pass through, the far more mobile alcohol does not pass. The capacity of the animal membrane for being moistened by, and its power of absorbing, the liquid, have a certain share in producing the result of its filtration through the membrane.[l The following table will show this fact: * The portion of water not chemically combined, has the greatest share in the properties of the tissues. tPressure required to cause water and any other liquids to pass through membranes. The pressure varies with different liquids. a The passage of liquids through membranes not in proportion to their fluidity. 1 The absorbent power of the membrane for the liquid has a share in the effect. 12 MOTION OF THE JUICES OF THE ANIMAL BODY. 100 parts, by weight, of dry ox-bladder, take up in 24 hours,of pure water...................... 268 volumes,, saturated solution of sea salt (brine)... 133,,,, alcohol of 84 per cent................ 38,,oil of marrow*....................... 17,, 100 parts, by weight, of ox-bladder, take up in 48 hours, — of pure water....................... 310 parts by weight of a mixture of 3 water and brine.... 219,,,, i,, i,,......... 235,,,,,, i,, 3......... 288,,,, -,, -A alcohol,......... 60,,,,,,......... 290,, 100 parts of dry pig's bladder take up in 24 hours,of pure water.................... 356 volumes,, brine................................ 159,, oil of marrow....................... 14 From these experiments it appears that the absorptive power of animal membranes for different liquids is very different. Of all liquids, pure water is taken up in the largest quantity; and the absorptive power for solution of salt diminishes in a certain ratio as the proportion of salt increases. A similar relation holds between the membranes and alcohol; for a mixture of alcohol and water is taken up more abundantly the less alcohol it contains.1 (') In regard to this property, membranes differ in no respect from 9ther animal textures, as was long ago proved by Chevreul. This distinguished philosopher found that the following substances absorbed, in 24 hours, of water, brine, and oil, — Cibic Centimnetres C. C. C. C. Water. Brine. Oil. 100 grammes of cartilage of the ear....... 231 125 100, tendons..178 114 8.6 100,, yellow ligaments of spine. 148 30 7.2 100,, cornea..461 370 9.1 100,, cartilaginous ligaments.... 319 - 3.2 100,o dry fibrine absorbed...... 301 of water and 148 of alcohol of 69 per cent. (Liebig.) 100,,,,.... 184 parts by weight or 154 by volume of brine. Animal membranes do not acquire, by absorbing alcohol or oil, those properties which they exhibit when saturated with water.f A dried bladder continues hard and brittle in alcohol and oil; its flexibility is in no degree increased by absorbing these liquids. When tendons, ligaments (CHEVREUL,) the yellow ligaments of the spine, or bladder, saturated with oil, are placed in water, the oil is completely expelled, and they take up as much water as if they had not previously been in contact with oil. It has been mentioned, that 100 parts of animal membrane (dry ox-bladder) absorb in 24 hours 268, in 48 hours 310 volumes of water, and only 133 of saturated solution of salt. It follows, of course, that when the bladder, saturated with water by 48 hours' contact, E Pd well dried in bibulous paper, without pressure, to remove superfluous water, is t:rewed with salt, there is formed, at all points where salt comes in contact with he water filling the open pores, a saturated solu* Absorptton of different liquids. tEffects of oil, salt, &c., on aemlbrar when dry, and when la the moist state. MEMBRANES SATURATED WITH WATER. 13 tion of salt, the salt contained in which diffuses itself equally in the water of the bladder. Of the 310 volumes of water which become thus saturated with salt, only 133 volumes are retained in the bladder; and in consequence of this diminution of the absorbent power of the bladder for the brine, 177 volumes of liquid are expelled, and run off in drops from the surface of the bladder. Membranes, fibrine, or a mass of flesh, behave exactly in a similar manner when in contact with alcohol. If placed in alcohol in the fresh state, that is, when they are thoroughly charged with water, there are formed, at all points where water and alcohol meet, mixtures of the two, and as the animaltexture absorbs much less of an alcoholic mixture than of pure water, more water is, of course, expelled, than alcohol taken up. 9'17 grammes of bladder, fresh, that is saturated with water (in which are contained 6'95 grammes of water, and 2'22 of dry substance,) when placed in 40 cubic centimetres of alcohol, weigh, at the end of 24 hours, 4'73 grammes, and have, consequently, lost 4.44 grammes.* In the 4'73 grammes which remain, are 2'22 grammes of dry bladder, and, of course, 2'51 grammes of liquid. If we assume that this liquid has the same composition as the surrounding mixture (which'is found to contain 84 parts of alcohol to 16 of water,) it will consist of 2'11 grammes of alcohol and 0'40 of water; and consequently, of the 6'95 grammes of water originally present, 6'45 grammes have been expelled, and replaced by 2'11 grammes of alcohol. For 1 volume of alcohol, therefore, retained by the bladder, rather more than 3 volumes of water have been expelled from it.; r Since, in this case, so much more water is expelled than is taken up of alcohol, the first result is a shrinking of the animal substance.(l) If the bladder could take up or absorb equal volumes of brine and water, or of alcohol and water, then when the fresh bladder was strewed with salt, or laid in alcohol, the volume of the absorbed liquid would be unaltered, and an equal volume of saline solution, or of diluted alcohol, would be retained by the animal tissue. But since the absorbent power of the tissue for water is diminished by the addition of salt, or of alcohol, it follows plainly, that a certain quantity of water must be expelled as soon as its character is changed by the addition of one of these substances. The relation of bladder, fibrine, and other animal substances, when saturated with water, to alcohol and brine, proves, that the shrinking (diminution of volume) of these tissues does not depend on a simple abstraction of water in virtue of the affinity of alcohol and of salt for that liquid; for it is quite certain that the attraction of alcohol to water, and that of water to alcohol, are respectively equal.: The attraction of the water within the tissue for the alcohol without, is just as strong as the power of the alcohol without to combine with the water within. Less alcohol is taken up, and more water given out, because the animal tissue has less attraction for the mixture of alcohol and water than for pure water alone. The alcohol without becomes diluted, the water within becomes mixed with a certain proportion of alcohol, and this exchange is only arrested when the attraction of the water for the animal tissue, and its attraction for alcohol, come to counterpoise each other. If we regard a piece of skin, or bladder, or fibrine as formed of a system of capil lary tubes, the pores or minute tubes are, in the fresh state, filled with a watery liquid, which is prevented from flowing out by capillary attraction. But the liquid contained in these capillary tubes flows out of them as soon as its composition is altered by the addition of salt, alcohol, or other bodies. (') Fibrine and other animal matters exhibit results quite similar to those obtained with bladder. 26'02 grammes of fibrine saturated with water (containing 6'48 grammes of dry fibrine and 19-54 of water) were reduced, in 45 grammes of absolute alcohol, to 16-12 grammes, losing, therefore, 9'90 grammes. Admitting the absorbed liquid to have the composition of the unabsorbed residue (70 per cent. of alcohol,) it appears, that for 1 volume of alcohol absorbed by fibrine rather more than 2~ volumes of water are separated. * Amount of water expelled from bladder by alcohol.'tMoist membranes shrink when strewed with salt, or placed in alcohol. t: The cause of this is the less affinity of the tissue for alcohol, &c., than for water. 14 MOTION OF THE JUICES OF THE ANIMAL BODY. If we lay together, one over tLe other, two portions of bladder, saturated with solution of salt of sp. g. 1'204, and over the upper one another piece of bladder of equal size, saturated with water, and if we allow them to remain thus, without pressure, we find, after some minutes, when the two pieces saturated with solution of salt are separated, that drops of saline solution appear between them, of whic.h no trace could previously be perceived. If the piece of bladder saturated with water contained 5 volumes of water, and the next piece 3 volumes of saline solution, there must be produced, by the mixture of both, 8 volumes of diluted saline solution, of which each piece of bladder must contain one half, or 4 volumes, if the absorbent power of the portion saturated with the original saline solution were increased by the addition of water in the same ratio as the absorbent power of the portion saturated with water was diminished by the addition of salt. The saline liquid would have given up 1j volume of saline solution to the other, and would have received from it 2' volumes of water. In this case, the mixture in the two upper pieces of bladder would occupy the same space which its constituents, water and saline solution, occupied in each singly. But the efflux of the liquid towards the, third or lowest piece of bladder saturated with saline solution, proves, that the two upper pieces retain a smaller volume of the mixture newly formed in their pores, than the one piece absorbed of water alone, and the other of saline solution alone. The power of retaining water is diminished by the addition of salt to the bladder saturated with water; liquid is expelled; but by the addition of this water to the bladder moistened with saline solution, the absorbent power of this piece of bladder is increased, not in the same ratio according to which the proportion of salt is diminished, but in a less ratio. The experiments above described show that the attraction of the porous substances for the water which they have absorbed does not prevent the mixture of this water with other liquids. The permeability of animal tissues to liquids of every kind, and the miscibility of the absorbed liquidswith others which are brought in contact with the tissues, may be demonstrated by the simplest experiments.* If we moisten one side of a thin membrane with ferrocyanide, of potassium, and the opposite side with chloride of iron in solution, we perceive in the substance of tile membrane a spot of Prussian blue immediately deposited. (JoH.?1UrLLER.) All fluids which, when brought together, suffer a change in their nature or in their properties, exhibit, when only separated by an animal membrane, exactly analogous results; they mix in the pores of the membrane, and the decomposition commences in its substance. If we tie up one end of a cylindrical glass tube with bladder, and fill it to the height of 3 or 4 inches with water or strong brine, neither the water nor the brine flows out through the pores of the bladder under this slight pressure. But if we leave the tube containing brine exposed to evaporation in the air, the side of the bladder exposed to the air is soon covered with crystals of salt, which gradually increase, so as to form a thick crust.t It is obvious that the pores of the bladder become fluid with brine; that, on the side exposed to the air,' the water evaporates; its place is supplied by fresh brine, and the dissolved salt is deposited at the external minute openings of the pores, in the form of crystals. If the tube be filled originally with dilute saline solution, the crust of salt is not formed on the outer surface of the bladder until the solution in the tube has reached, by evaporation, the maximum of saturation. Before this takes place, we can perceive in the tube, if we set the liquid in motion, two strata, a heavier and a lighter, the latter swimming on the former. Whefi these strata can no longer be observed, the liquid is in every part saturated with salt; and now, by further evaporation, crystals are deposited on the outer surface of the bladder. This last circumstance proves that the amount of salt in the liquid is uniformly distributed from below upwards, from the specifically heavier to the specifically lighter part. If we immerse the tube closed with bladder, and filled with saline solution, in pure water, the latter acquires the property of precipitating nitrate of silver, even * Animal tissues are permeable to liquids of every kind, which act on each other in the sub. stance of the tissues. t Deposition of salt on the outside of bladder from brine on the inside. MIXTURE OF THE LIQUIDS. 15 when the contact has lasted only the fraction of a second.* The brine filling thaopen pores of the membrane mixes with the pure water, and the latter acquires a certain quantity of salt. In like manner, the pure water acquires a saline impregnation, when it is placed in the tube instead of brine, and the outer surface of the bladder is placed in contact with solution of salt. When the tube, closed with bladder, and filled with brine, is left for a long time with the closed end immersed in pure water, the amount of salt in the latter increases, while that of the brine diminishes, till at last the two liquids, separated by the bladder, contain the same relative proportions of salt and water. If the liquid in the tube contain, dissolved, other substances which give to it properties different from those of pure water, and if these solutions be miscible with water, the mixture of them with the water takes place exactly as in the case of brine.t This is true of saline solutions of every kind; of bile, milk, urine, serum of blood, syrup, solution of gum, &c., on the one side, and pure water on the other. The concentrated liquid loses, the water or diluted liquid gains, in regard to saline impregnation. If we fill the tube with water, and place it in a vessel with alcohol, the water becomes charged with. alcohol, while the alcohol becomes diluted with water. There is observed, in these circumstances, that is, when two dissimilar liquids, separated by a membrane, mix together, a phenomenon of a peculiar kind; namely, in most cases a change of volume in both liquids, while the mixture goes on.$ The one liquid increases in bulk, and rises; the other diminishes in the same defree, and consequently sinks below its original level. This phenomenon of mixture through a membrane, accompanied with change of volume, has been distinguished-by DUTROCH1rT, under the name of ENDOSMOSIS and ExosMoss; endosmose is the name given when the volume increases-exosmnose, when it diminishes.~ Very generally, however, we attach to these terms the idea of the unknown cause or group of causes which, in the given case, produce the change of volume; in the same sense as that in which the term capillary action includes the causes which determine the ascent of liquids in narrow tubes. In all cases, the increase in volume of the one liquid is exactly equal to the decrease in volume of the other, after making allowance for the contraction which the liquids undergo by simple mixture (as in the case of alcohol and water, oil of vitriol and water, &c.,) as well as by evaporation. The unequal concentration, or the unequal density of the two liquids, has a decided influence on the rapidity with which the change of volume takes place; but this cannot be viewed as the cause of that phenomenon. In most cases the denser liquid increases in volume, in others the reverse occurs. When, for example, the tube contains brine, and the outer vessel pure water, the brine, that is the denser liquid, increases in volume;1 but when the tube contains water, and the outer vessel alcohol, the water, that is, the denser liquid, diminishes in volume. With iegard to the mixture of the liquids, the bladder takes a distinct share in the process, inasmuch as it has pores, through which the two liquids are brought in contact. With reference to the porosity of the bladder, the rapidity of the mixture of the two liquids is directly proportional to the number of particles, which, in a given time, come into contact; it depends also on the surface (the size of the membrane,) and on the specific gravity of the liquids. The influence of extent of surface on the time required for mixture requires no particular elucidation; that of the unequal specific gravity is rendered evident by the following experiments.~ * Saline solutions pass very rapidly through bladder. tThe same is true of bile, milk, urine, serum, &c. T Change of volume when two dissimilar liquids mix through a bladder.? Endosmosis and Exosmosis. The change of volume does not depend alone on the relative density of the liquids. ~ Influence of the unequal density of the two liquids, when the lighter liquid is above the membrane. 16 MOTION OF THE JUICES OF THE ANIMAL BODY. Fig. 2. If the bent tube a b (Fig. 2,) one end of which is tied over with bladder, and the other open, be filled with brine colored blue,(') and if pure water be placed in the tube c, there is soon perceived under the bladder a colorless or nearly colorless stratum of liquid, which continues for hours to float in the same place. If the bent tube a b be filled with colorless brine, while c is filled with pure water colored blue, there is found, after a time, above the bladder, a colorless or nearly colorless stratum of liquid. It appears from this, that an exchange of both liquids goes on through the substance of the bladder; in the first experiment colorless water passes from the tube c to the colored brine in the tube A a b; in the second, colorless brine passes from the tube a b to the colored water in the tube c. It is obvious that the brine in the tube a b, which is in contact with the bladder, becomes diluted by the addition of water from the tube e; but this diluted brine is specifically lighter than the original brine which is below it, and remains tierefore floating at its surface. On the other hand, the water in the tube c, when mixed with brine from the tube a b, becomes heavier than the pure water, and rests, therefore, on the upper surface of the bladder, or that which is turned towards the water. Hlence it follows, that from the moment when these two strata have been formed above and below the bladder, neither concentrated brine nor pure water comes any longer in contact with the bladder. From.the bladder downwards, in the tube a b are strata of liquid, containing successively more salt; from the bladder upwards in the tube c are strata containing successively more water. In the beginning of this experiment we observe, that the volume of the water and of the brine changes in both tubes; the liquid in the limb b rises from 1 to 2 lines; but as soon as the strata above mentioned have been distinctly formed above and below the bladder, hardly any further rise is perceptible, although the mixture of the liquid proceeds, and the water in c becomes constantly more charged with salt, while the brine in a b loses salt. If we reverse the positions of the two liquids in the apparatus Pig. 3. Fig. 2, or what is simpler, if we close with bladder a tube centimetre (4 ths of an inch) wide, fill it with brine, and immerse the end closed with the bladder in a wider vessel filled with pure water, giving to the tube an inclination of about 45~, we may observe (most distinctly when both |___f A liquids contain some fine particles of indigo suspended) in _ __-_ both liquids a continual motion.* We see in the tube (Fig. 3) a current of liquid rising from the bladder in the direction of the arrow, and flowing down again on the opposite side. A similar circulation is observable in the vessel of water. If the tube a, with brine, is about 2 centimetres (-4ths of an inch) wide, and if we support it vertically in the vessel b of B/g. 4. water, the motion proceeds from the middle, and in both the tube and the vessel we perceive currents in opposite directions. (Fig. 4.) These currents hardly require explanation. To the brine in the tube a, pure water passes through the bladder; there is formed above the bladder a mixture containing less salt, and therefore specifically lighter than the brine; this mixture rises, and the X denser brine descends to occupy its place. On the other hand, the pure water receives through the bladder salt, and becomes thereby specifically heavier; while it sinks to the bottom of the vessel, its place is supplied by water containing (') For this purpose it is best to take a solution of indigo in sulphuric acid, diluted, * When the heavier liquid is above the membrane. MIXTURE OF TWO LIQUIDS THROUGH A MEMBRANE. 17 less or no salt, and therefore specifically lighter, which again comes in contact with the bladder. As long as the motions just described are perceptible, we observe a constant increase in the volume of the brine in the tube a (Fig. 4,) or a diminution..in the volume of the pure water in the vessel b. When the motions cease, the rise of nquid in the tube is arrested, and when this takes place, the two liquids are found to possess almost exactly the same specific gravity. When the two strata of liquid on either side of the bladder are little different in composition (as soon comes to pass in the expei-iment (Fig. 2) where the saline contents of the liquid which fills the pores of the bladder can hardly vary from that of the next stratum,) the mixture of the liquids takes place, but without further change of volume. But when an exchange of the mixtures on the opposite sides of the bladder can occur in consequence of their, different specific gravity, and when a continued-difference between the strata on opposite sides of the bladder is thus determined, then, so long as (in the case of brine and water, for example) one side of the bladder is in contact with a concentrated, the other with a more diluted solution, the change of volume in the two liquids continues. As appears from these experiments, the change of volume depends on a difference in the character of the two liquids which are connected through the bladder; and the time during which change of volume occurs is in direct proportion to the time during which this difference in character subsists. The greater the difference in character and composition between the liquids, and the more rapidly this difference is renewed by the exchange between the strata in contact with the opposite sides of the bladder, the more, rapidly does the one liquid increase, and the other diminish in volume. The following apparatus is very convenient for measuring the Fig. 5. change in volume, caused by the mixture of two liquids separated by a membrane. The tubes a and b, (Fig. 5) are of equal width, and are best taken from the same tube; a is closed with bladder, and filled up to a certain point with the liquid whose increase in volume is to be determined. It is then fitted by means of a good cork into the wider tube c, which contains distilled water, care'being taken to exclude all air bubbles. At d lies a small lead drop, which acts as a valve in shutting the opening of the capillary tube connecting c with b. Pure water is now poured into b, and in order to keep in equililbrium the lead drop at d, rather more water is added than exactly suffices to bring the liquids to the same level in both tubes. The liquid in a increases in volume, and the height to which it rises may be read off by means of any division into equal parts C by measure; the level of' the liquid in b sinks in an equal ratio. If we keep the liquid in b, by the addition of fresh water, at the _ original level, and if we ascertain the weight of the added water, by pouring it out of a dropping bottle, and determining the loss of weight in the dropping bottle, we learn, at the same time, the weight and the volume of the water which has risen from c into a. This apparatus admits, of course, of a number of variations and improvements. I have employed it to determine the relation, between brine and water, under the circumstances just described. It appeared, among other things, that when the tube a is filled with saturated solution of sea salt, the volume of the liquid increased by nearlytone half; that is, 200 volumes of such a solution increased to 300. These determinations are, however, not the object of the present investigation, and therefore I pass them over entirely. The following arrangement, (Fig. 6) will probably be found preferable to the one just described, in many cases. Its construction depends on the observation, that for the phenomenon itself, and for the result of the experiment, it is entirely a and after adding subacetate of lead as long as sulphoindigotate and sulphate of lead are precipitated, to separate the precipitate by filtration and dry up the filtered liquid in the water bath. A mere trace of the blue residue suffices to color blue large masses of liquid. * The change in volume may be measured. 3-" 18 MOTION OF THE JUICES OF THE ANIMAL BODY. matter of indifference whether the tube be closed with a single,.Fi. 6. double, or treble layer of bladder.(l) For experiments on very thin c D membranes which are permeable to liquids under a very low pressure, the apparatus (Fig. 5) is obviously better adapted. For the explanation of the phenomenon we have to distinguish — 1. The mixture of different liquids. 2. The change in their volume. As'to the mixture of two liquids of dissimilar nature and characters, this always depends on a chemical attraction.* In a mixture of alcohol and water, or of brine and water, there is in every part the same proportion of particles of alcohol and water, or of salt and water. If in the former, the lighter particles of alcohol lying at the bottom of the vessel were not retained, in the place and arrangement which they occupy, by the surrounding particles of water, they would c undoubtedly rise towards the surface. In like manner, the particles of salt in the brine are sustained and prevented from sinking by the lighter particles of water which surround them.. Without an attraction, which all the particles of alcohol or of salt must have towards all'the particles of water, or all the particles of water must have for all those of salt and alcohol, a uniform mixture cannot even be conceived. If but one particle of alcohol were less powerfully attracted than the surrounding particles, it would rise to the surface; and in like manner, the particles of salt would, in consequence of their greater specific gravity, gradually occupy the bottom of the vessel, were it not that a cause prevents them from rising or falling; and this cause, can be nothing but an attractive force, which retains them in the place where they happen to be. The cause which effects a change in the place or in the properties of the ultimate particles or atoms of dissimilar substances, when these particles are in absolute contact, or at infinitely small distances from each other, as well as the cause which manifests itself as a resistance to such-changes of place or properties, we call CHEMICAL ATTRACTION;t and in this sense the mixture of two dissimilar liquids, the simple moistening of a solid body, the penetration and swelling of it:y a liquid, are effects in which chemical affinity or attraction has a decided share; and although we are accustomed to limit the notion of affinity to such cases as exhibit a change perceptible to our senses, in the properties of the substances employed, as, for example, when sulphuric acid and lime, or sulphuric acid and mercury combine together, this limitation arises from the imperfect apprehension of the essence of a natural force. Every where, when two dissimilar bodies come in contact, chemical affinity is manifested. It is a universal -property of matter, and by no means belongs to a peculiar class of atoms, or to a peculiar: arrangement of these. But chemical combination is not, in all cases, the result of contact. Combination is only one of the effects of affinity, and occurs when the attraction is stronger than all the obstacles which are opposed to its manifestations. When the forces'or causes, which oppose chemical combination, heat, cohesive attraction, electric attraction or whatever they may be called, preponderate, then chemical combination does not take place; and effects of another kind are manifested. Melted silver in a crucible, surrounded with red hot coals, in a place, therefore, where we should hardly anticipate the presence of free oxygen, absorbs as much (') In these'experiments membranes of all kinds may be used. With the thinner membranes, such as the bladder of the calf and the pig, the experiments are more rapidly completed than with the thicker, such as the gall-bladder and urinary bladder of the ox. The peritoneum of the ox and calf is preferable to all others. The tube c is tied with bladder under water. * Causes of the mixture of dissimilar liquids. i Chemical affinity is the chief cause of mixture. 4 Affinity is everywhere active between bodies in contact CHEMICAL AFFINITY IS UNIVERSALLY DIFFUSED. 19 as ten or twelve times its volume of that gas. Metallic platinum exhibits the same property in a far higher degree; for from the atmospheric air, a gaseous mixture in which oxygen forms only the' fifth part, that metal (in the form of a blacl. powder) condenses on its surface, at the ordinary temperature, an enormous quantity of oxygen gas (without any nitiogen,) and acquires thereby properties, which it does not otherwise possess.(') And when oxide of chromium, fragments of porcelain, or asbestus, at high temperatures, effect the combination of two gases, oxygen and hydrogen, or oxygen and sulphurous acid, which gases do not combine at the same temperature, unless when in contact with these solid bodies, it is to the chemical attraction or affinity of these solid bodies that we must ascribe this effect. The solution of a salt in water is an effect of affinity, and yet no one property, either of the salt or of the solvent, is thereby altered, except only the cohesion of the saline particles. Sea salt, the crystals of which are usually anhydrous, takes up, at very low temperatures, 38 per cent. of water of crystallization;* not because any new cause acts which increases its affinity for the, particles of water (for cold is no cause, but the absence of a cause,) but because the higher temperature acted as an obstacle, opposing their chemical combination. The force of affinity is all the time present and undiminished. When we add alcohol to the solution of a salt in water, we observe, that now the salt separates from the liquid in the form of crystals, doubtless only because, by the addition of another chemical force, the amount of attraction between the particles of the salt and those of the water has been altered. The aqueous particles, which were combined with the saline particles, manifest an attraction for the particles of alcohol; and as the latter have no affinity, or only a very feeble affinity, for those of the salt, the attraction of the saline particles for each other is strengthened. This attraction was present in equal force before the addition of the alcohol, but the resistance which opposed'their union (the chemical attraction for them of the aqueous particles) was more powerful.t The alcohol was not the cause of the separation. The cause of the separation of the salt from the liquid, its crystallization, is. at all' times the force of cohesion; and by the alcohol the cause which opposed its manifestation was removed. The affinity of potash for sulphuric acid is known, and sulphate of potash readily dissolves in water. If we add, to a saturated solution of that salt, an equal volume of aqua potassae of sp. g. 1.4, there is immediately formed a crystalline precipitate of sulphate' of potash, and'the sulphuric acid is separated in this form from the water. In these cases the chemical; effect (the separation) depends on the presence of a certain quantity of the liquid which is added (such as aqua potasswe, alcohol, &c.,) but in many other cases there is required only a slight alteration in the quality of the solvent to effect separations of this kind. When hydrochloric acid is added to a solution of ferrocyanide of potassium, ferrocyanic acid is set free, and remains dissolved in the liquid. If now the vapor of boiling ether be passed through the mixture, there occurs, after a few moments, a complete separation. The whole of the ferrocyanic acid is deposited from the liquid in the form of white or bldiish-white crystalline scales, which generally appear in such quantity as to render the whole mass semisolid. In proportion as the vapor of ether is dissolved by the water, the latter fluid loses entirely its solvent power (its affinity) for the ferrocyanic acid. The coagulation of albumen by ether depends on a similar cause. The capacity of solids to become moistened by liquids, and, in short, all (1) According to Doebereiner, platinum black condenses 252 times its volume of oxygen. Its effect in- oxidizing alcohol, pyroxilic spirit, &c., is familiar to every chemist.-W. G. * Crystallization of sea salt. Precipitation of salt from its solution by alcohol; of sulphate of potash by caustic potash; of ferocyanic acid by ether; of suspended mud by alum. 20 MOTION OF THE JUICES OF THE ANIMAL BODY. phenomena connected with chemical affinity, are affected, altered, increased, or destroyed by causes quite analogous. After heavy rains, the water of many rivers becomes turbid and opaque from the presence of a fine clay. These suspended particles of clay are so fine as to pass through the finest filters; and their adhesion to the water is so great, that such water does not clear after standing for weeks. The water of the Yellow River, in China, possesses, during the greater part of the year, this character; and from the French missionaries, we know that alum is universally employed in Pekin to clear it. In fact, if a crystal of alum be held in such a water only for a few seconds, we observe the sediment separating in large thick flocculent masses, the water becomes transparent, and hardly a trace of dissolved alum is to be detected by the most delicate re-agents. Chemistry is acquainted with a number of similar means for causing the separation from liquids of suspended precipitates.. In these cases we see, that by an alteration of the quality of the water, produced by what we call mere mixture with a foreign body, its power of combining with others is destroyed or weakened. It is well known that the force with which, in a solution, the particles of the liquid and those of the dissolved body attract each other, is very unequal in different cases;* and in this point of view the- action of many solid bodies on saline solutiQns is very remarkable; inasmuch as it is thereby demonstrated, that the-molecular force, which determines the phenomena of cohesion, and the moistening of solid bodies by liquids appears to be identical with chemical affinity, since chemical cQ.mpounds can be decomposed by means of it. Professor GRAHAM has shown that common charcoal, deprived by acids of all soluble ingredients, completely removes the metallic salts or oxides fromn solutions of salts of lead, tartar emetic, ammoniated oxide of copper, chloride of silver in ammonia, and oxide of zinc in ammonia; while other solutions, such as that of sea salt, suffer no such change. A bleaching solution of hypochlorite of soda loses entirely its bleaching properties by agitation with charcoal; and iodine can be removed by the same means from its solution in iodide of potassium. Every one is familiar with the action of finelydivided platinum., with that of silver on the deutoxide of hydrogen; as well as with that of charcoal on dissolved organic matters, coloring matters, &c.; and freshly-precipitated sulphuret of lead, sulphuret of copper, and hydrate of alumina, resemble the latter in their action. Many organic substances, such as woody fibre and others, act on dissolved matters, such as salts of alumina or of oxide of tin, just as charcoal does; and we know that the application of mordants in dyeing, and dyeing itself depend on this very property. The adhesion of the solid coloring matter to the cloth which is died with it is the result of a chemical affinity so feeble, that we hardly venture to give the molecular force that narne in this case. From a piece of woollen cloth dyed with indigo, the indigo is completely separated, by mere beating, continued for some time, with a wooden hammer, so that the wool is at last left white. The surface of the solid body exerts, as these facts prove, a very unequal attraction on the molecules, which come in contact with it. Researches on capillary attraction have shown that, with one and the same liquid, water, for example, the substance of the solid body has no influence on the height to which the liquid rises on it. On slices of box-wood, clay-slate, or glass, the rise of the liquid above the surface of the water is the same exactly as in the case of a plate of brass. (HAGEN.) In the case of other liquids, the particles of which are entirely homogeneous, the same law may be assumed in theory; but with such liquids as contain foreign bodies in solution, a change in the capillary attraction must be produced by the presence of these bodies, because by them the cohesion of the liquid is altered; and, perhaps, still more because the liquid ceases to be homogeneous, when the attracting wall has a stronger affinity for the particles of the dissolved body than for those of the solvent. From what has been stated, it appears, that the mixture of two liquids is the result of a chemical attraction; for how otherwise could chemical compounds, *Action of solids on dissolved matters. LAWS OF TIEE MIXTURE OF DIFFERENT LIQUIDS. 21 such as the solution of a salt in water, be decomposed, or a chemical attraction be overcome, by its means? Two liquids of different chemical properties, which are miscible together, and which, therefore, have a chemical attraction for each other, mix readily at all points where they come in contact.* By motion, shaking, &c., the number of points of contact within a given time is increased, and the formation of a uniform mixture is thus accelerated. If these liquids be of equal, or still better, of unequal, specific gravity, they may be, with the aid of some precaution, stratified one above the other. This is, in point of time, the most unfavorable case for the mixture, since proportionally small surfaces come in contact. But. wherever they do come in contact, it is, after a very short time, impossible to detect any limit between them. In a cylindrical vessel containing, solution of salt, the saline particles at the surface are attracted and sustained by aqueous particles, which exist at the sides of the saline particles and from the surface downwards. From the surface upwards, tthe attracting aqueous particles are absent. Now it is evident that when the surface is brought in contact with pure water, a new attraction is added to those previously existing, which acts in an opposite direction, namely, the attraction of the aqueous particles floating on the surface for the saline particles, and vice versa (the attraction of the saline particles to the aqueous particles in contact with them.) At the place where pure water and brine are in contact, there is thus formed a uniform mixture of the two, which upwards is in contact with pure water, downwards with brine. Among these three strata, of which the upper contains no salt, the lower less water, a new division takes place; the more strongly saline stratum loses salt, the pure water becomes saline, and in this way salt and water are at last uniformly distributed throughout the liquid. If we fill one limb of the tube (Fig. 7,) as far as a, with brine Fig. 7. colored blue, and the other limb with water, we find, in the course of a few days, the water colored blue, and the proportion of salt in both limbs equal.t It has been mentioned at p. 15, that, in a tube closed with bladder, filled with diluted solution of salt, and exposed to evaporation, the salt is not deposited in crystals on the outer surface of the bladder till the whole liquid in the tube has reached, in consequence of evaporation the maximum of saturation. The'water evaporates from the exterior of the bladder, but no salt is deposited, as long as' a liquid exists within which can still dissolve salt; and in this way the heavier saline particles are distributed to- wards the interior, and upwards through the whole liquid, or, what amounts to the same, the lighter aqueous particles, which can still'I...... dissolve salt, are distributed downwards towards' the external surface of the bladder. This distribution of salt through water takes place in the same manner as the conversion of bar iron into steel.t Rods of malleable iron, as"is well known, are kept ignited between strata of charcoal, whereby the surface of the iron in contact with the charcoal takes up carbon, and becomes a carburet of iron. The stratum of iron lying next under this surface, which has the same attraction for carbon, acquires carbon from'the superficial stratum immediately in' contact with it, and in its turn gives carbon to the stratum below itself. This process, if continued long enough, has no limit till all the strata of particles have acquired an equal proportion of carbon, that is, till- they are all saturated with it. A piece of red-hot malleable iron, if kept a few moments in contact with pig iron (a carburet of iron) is found to be already converted into steel at the points of contact. The mixture of liquids depends on the same principle; and we may suppose that ththi distri* Laws of mixture of two liquids. t Experiment showing the uniform mixture of two liquids. tThe distribution of salt through water, resembles'the conversion of iron into steel by cementation. 22 MOTION OF THE JUICES OF THE ANIMAL BODY. bution is mutual, because their particles may move in all directions, and that consequently saline particles move towards aqueous particles, as well as aqueous towards saline particles, in, virtue of their mutual attraction. From a solution of sulphate of copper in ammonia, placed in a tall glass cylinder, there is gradually separated, if we pour a stratum of alcohol on the surface, and if we prevent the formation of a coherent crust which impedes the contact of the liquids, the whole of the ammoniated sulphate of copper, while the deep blue solution becomes colorless, because by the distribution of the alcohol through the solution a mixture is formed, in which the salt is insoluble. The'rapidity of mixtur,e of two liquids depends on the degree of their chemical affinity;* and the unequal mobility of the particles of one or the other liquid has a favorable or unfavorable influence on the result. When the one liquid is heavier than the other, and of tough, viscid consistence, a much longer time elapses before the ingredients of the tougher or heavier liquid reach the surface from the bottom of the vessel; and in this case the greater density and the less mobility of the particles are obstacles to the mixture. On the other hand, if the heavier or more viscid liquid be placed above the lighter, the mixture takes place rapidly; at the points where both liquids are in contact is produced a mixture, which, being heavier, descends, whereby the heavier liquid above is continually brought in contact with new. surfaces of liquid. The very same phenomenon is observed in solution.t A fragment'of sugar, when covered.with water at the bottom, of a narrow cylinder, dissolves very slowly, while, if suspended just below the surface, it rapidly disappears. In the former case there is produced round the sugar a thick syrupy viscid solution, which protects the undissolved part of the sugar for a long time from contact with the water; in the latter there is formed at the surface a solution, which descends in strie, and gradually disappears, while by the change of place thus induced, new portions of water are constantly brought in contact with the undissolved sugar, and are thus enabled to exert their solvent powers. If skin and membranes consist of a cohering system of very narrow tubes, it is obvious, that when two dissimilar, but miscible liquids are separated by such a rissae, the pores of the tissue will fill with each of the two liquids. In, all situations, a lhere the liquids came in contact'in the substance of the membrane, a mixtnre takes place,. and this mixture is extended equally towards both sides. If there be brine on one side of the bladder, and water on the other, there must be formed, in the middle,'or at some point of the bladder, a diluted brine, which er thne side in contact with the water yields salt to that water, while on the opposite side the strong brine mixes with the diluted brine in the bladder. The substance of the bladder has no influence onthis mixture, because it can' produce, no change of place on the part of the saline or aqueous particles, for this is the result of the chemical affinity acting between the particles of salt and those of water. $ Now since the rapidity of the mixture of two liquids stands' in a direct pro-.portion to the amount of surfaces coming into contact within a given time, and since the liquids, separated byt a bladder, can only conie in contact through its pores, while the number of points of contact is diminished by the presence of the non-porous parts of the bladder, it'follows, that, exclusive of all other effects, the time required for mixture must be lengthened -by the interposition of a bladder. In the absence of the bladder, the mixture would take place exactly as when it is present, except in regard to time. When the heavier brine is under, the water above the bladder, the two liquids mix more slowly than without the bladder. But since a bladder, inasmuch as a feeble hydrostatical pressure is not propagated through its pores, allows us' to place a heavier liquid above a lighter, and to retain * Mixture is influenced by chemical affinity, by unequal mobility, and by unequal density in the liquids. t Effect of position on the solution of a solid. $ Rapidity of mixture. CHANGE OF MIXTURE IN LIQUIDS.'23 it in that position; this circumstance has the effect of promoting mixture, the ultimate cause of which is, not the bladder, but the specific gravity of the liquid.The bladder is a means of enabling the specific gravity to influence mixture. -The foregoing remarks appear to me sufficiently to elucidate the share taken by the bladder in the mixture of two dissimilar liquids placed on opposite sides of'it. With respect to the change of volume in the two liquids which become mixed through the bladders, we must consider, that the moistening or absorbent power of a solid body, as well as the power of a liquid to moisten other bodies, is the result of a chemical action.t Liquids of different properties, or of different chemical characters, are attracted with unequal degrees of force by solid bodies, and exert towards them unequal degrees of attraction, and if we alter even in a system of- capillary tubes, filled to a certain height with a liquid, the chemical nature of that liquid, we change thereby the height at which the liquid stands. In,an animal tissue saturated with water, the water is prevented from flowing out by the mutual attraction, and by the capillary force, but if the attraction of the organic parietes for water be diminished by the addition of alcohol or of salt to the water, a part of it flows out. To this must be added, that the water absorbed by an animal texture when it enters the capillary tubes, exerts, in virtue of its attraction for the tubes, a certain pressure, by which the vessels are swoln and enlarged. The particles of liquid in these tubes undergo a counter-pressure from the elastic parietes, by which pressure, when the attraction of the liquid particles for the solids is diminished by any new cause, the amount of expelled fluid is increased. The organic parietes of the tubes, saturated with water, are affected by alcohol just as a salt is when dissolved in water. On the addition of alcohol, or of another liquid, the water separates from the salt, or from the parietes, or the parietes separate from the water. If the animal tissue possessed as great an attraction for the newly-formed mixture as for the water alone, the volutme of the liquid would not change. The mixture would take place, but no water would flow out. A bladder, saturated with water, when brought in contact with alcohol, shrinks together, a part of the water separates from the animal matter, but there always remains in the bladder a certain amount of water, corresponding to its attraction for the bladder and for the alcohol; just as the solutions of many salts which have a strong attraction for water (such as a metaphosphate and acid phosphate of soda,) and are insoluble in alcohol, are separated by the addition of alcohol into two strata of liquid, the heavier of which is-a more concentrated solution of the salt in water, containing a little alcohol, while the other, the lighter, is an aqueous liquid containing much alcohol. The alcohol and the salt divide between them the water of the solution. When we add, to a mixture of equal parts of acetone and water, a certain quantity of dry fragments of chloride of calcium, the first fragments which are added deliquiesce and dissolve entirely in the mixture.t But if we go on adding the salt, a separation soon occurs, two strata of liquid are formed, of which the upper contains acetone and water, the other is an aqueous solution of the chloride with a little acetone. If we add still more of the chloride, water i.s abstracted from the acetone of the upper stratum, and when a proper quantity has been added, the acetone retains no tirace of water. If we suppose, that of the two originally formed strata of liquid, one of them, namely that which sinks and contains chloride of calcium dissolved, is in contact with a current of dry air, the water of this solution will evaporate, the solution will thus become stronger, and in consequence of its increased concentration will be able to remove a new portion of water from the mixture of acetone and water above it; and this will continue till the acetone is entirely deprived of water. If in the place of the chloride of calcium we put a bladder, and, in place of the acetone and water, diluted alcohol, we have the finest example of the unequal In certain circumstances, the interposition of a membrane accelerates mixture. f Change of volume in liquids which mix through a membrane is the result of chemical affinity modifying capillary attraction., Action of chloride of calcium on a mixture of acetone;and water. 24 MOTION OF THE JUICES OF THE ANIMAL BODY. attraction which the animal tissue exerts on the two ingredients of the mixed liquid.* It is known from the experiments of SOEMMERING, that spirits of a certain strength, inclosed in a bladder, which-is opposed to the air, lose by evaporation only water, and that at last anhydrous, or nearly anhydrous (absolute) alcohol is left in the bladder. When strong spirits of wine are used, the bladder remains dry externally; when weaker spirits are employed, it becomes moist, and alcohol evaporates with the water. In virtue of the unequal affinity of the bladder for alcohol and for water, a complete separation is here effected. The water of the mixture is absorbed and evaporates from the outside of the bladder; the alcohol remains in the bladder. As yet, we are acquainted with no substance which can replace the bladder in this operation; and indeed, the affinity of the gelatinous tissues (membranes, &c.) for water must exceed that of all other animal tissues, since a rise of temperature, of a few degrees only, suffices to enable water to dissolve that tissue perfectly into a jelly. MEGNUS assumes, " that the particles of every solution, for example, of a salt in water, adhere more strongly to each other than do those of the solvent, for example, of water; consequently, the solution would be less fluid, and pass with greater difficulty through very narrow openings, than water, if we take for granted that the parietes of the openings act alike towards both. It would follow from this, that, the more concentrated a solution, the less easily would it pass through the same openings."t, "Let us now try," pursues MAGNUS, "with the aid of these assumptions, (which, as appears from the experiment Fig. 1, are perfectly accurate and demonstrable for many saline solutions, although there are, according to the researches of POISEULLE, a number of exceptions(l) ) to explain the phenomena of ENDOSMOSIS." Both the brine and the' water will penetrate into the pores of the bladder, and brine will pass.from the pores to the water, as well as water to the brine, in virtue of their mutual attraction, till a complete equilibrium is established. Further, since the force which attracts the water to the brine is exactly the same as that which attracts the brine to the water, as much water as brine would pass through the bladder, if both liquids could pass with equal facility through the pores. Since, however, this is not the case, unequal forces are required to urge the two liquids through the pores; or with equal forces, unequal quantities of the two pass through in equal times. There is consequently added more of that which passes most easily, the water to the brine, than of the latter to the water, and the level of both liquids must change, if no other force oppose this change."(2) According to this theory, brine and water exist in the pores of the bladder in a state of motion, and the chemical affinity, which the particles of the brine have for the particles of the pure water, and conversely, which the particles of water have for those of salt, is considered as the cause of this motion. The unequal velocity, which makes more water flow in a given time to the brine than brine or salt to the pure water, is, according to MAGNUS, determined by the unequal resistance which the substance of the bladder opposes to the passage of the two liquids. Now, however narrow the tubes may be, in which molecules are set in motion by an external force, it may always be assumed, that that part of the molecules, which is immediately in Contact with the wall of the tube, either is not in motion, or possesses only a snfall velocity, and the velocity of efflux must be a function of the cohesion, and at all events not dependent on the wall of the tube. If now the effilux of the water on one side of the bladder is produced by the attraction of the saline particles for the water, and the efflux of the brine on the other side is produced by the attraction of the aqueous particles for the saline (1) Ann. de Ch. et de Phys. 3rd series, xXi. pp. 84 et seq. 2) Poggendorff's Annales, x. p. 164. * Effect of evaporation through a bladder in concentrated alcohol, t Views of Magnus on Endosmosis. ATTRACTION OF THE MEMBRANE FOR LIQUIDS. 25 particles, it is impossible to explain how water and brine can move in the same tube with unequal velocity in opposite directions; the two liquids being supposed to have a mutual attraction, that is, to be miscible. This attraction must act within the tube just as well without; and we might, therefore, suppose, that when the two liquids have become mixed, the mixture could only move in one direction with a medium velocity. Assuming that a mixture is formed in the open orifices of the pores or tubes, or ill any part of them, it is difficult to see, why saline particles should not pass from one side to the, water, or aqueous particles to the saline ones in the bladder, since the mutual attraction must be regarded as equal on both sides. The chemical affinity of the two liquids does not explain the efflux. If we suppose, that in certain pores only brine, in others only pure water moves, the phenomenon ought not to occur when all the pores are filled with water or with brine, or when the tube is tied with a double, treble, or fourfold, bladder. But the properties of bladder are seen in the finest as well as thickest membranes, and one, two, or three layers make no difference in the ultimate result.(l) The kind of influence which the nature of the partition, or its attraction for the liquids in contact with it, exerts on the phenomenon, is seen by comparing the action of an animal membrane with that of a thin sheet of caoutchouc.* In -a tube, closed with bladder, which is filled with alcohol, and immersed in pure water, the volume of alcohol is increased; more water passes to the alcohol than alcohol to the water.t If. without making any other change in the experiment, the tube be closed with a thin sheet of caoutchouc, the volume of the alcohol now diminishes while that of the water increases. Here, all the circumstances of the mixture of the two liquids have remained the same except the nature of the partition, which makes the difference in the resLlt. When we fill with brine a tube, closed with bladder, (Fig. 8,) Fig. 8. and place it in a vessel of water, so that the bladder and water only communicate by a single'drop, the liquid in the tube increases in bulk, and rises in the tube, as if the bladder had been immersed in the water; but the drop becomes gradually smaller, till after an hour or two, a complete separation takes place, and the drop tears itself away from the water.(2) If the cause of the change of volume in this experiment were the unequal resistance which the bladder opposes to the passage 6f the two liquids with equal attraction (equal' force) on both sides, the phenomenon just described would be inexplicable; for a resistance can no doubt impede, but is not capable of producing motion. But we see, that the waterin this experiment is raised to a higher level, and moreover, the tearing asunder of the drop can only be the effect of a powerful attraction, residing in the substance of the bladder. (1) With respect to the theory, that, when a saline solution is mixed with pure water, if the two liquids are separated by a membrane, particles of salt alone pass through the pores of the bladder to the water, and particles of water alone to the brine, the following experiments may throw some light on the question. For the sake of greater accuracy, the results were determined by weighing. The apparatus, Fig. 3, was used. The tube contained 8-67 grammes of saturated brine, in which were 2'284 grammes of salt and 6'38 of water. After 24 hours it had gained 1-79 grammes in weight, and it now contained only 0-941 grammes of salt. It had therefore lost 1'343 grammes of salt, and gained 3-13 of water. According to the above theory, 1 atom of salt and [2] If we pour into a tube, 4 of an inch wide, and closed with bladder, as much mercury as covers the surface of the bladder, then fill it with brine, and place it in pure water, the volume of the liquid in the tube increases exactly as if the mercury were not there. * The nature of the membrane has an important influence. t Experiment with bladder, and with caoutchouc. 4 26 MOTION OF THE JUICES OF THE ANIMAL BODY. If the moistening of solid bodies by liquids be the effect of a chemical attraction the force of which is different in dissimilar liquids, it follows that, when a porous body is saturated with a liquid, and brought in contact with a second liquid, which has a stronger attraction for'its substance than.the first has, then the liquid must be displaced from the pores by the second, even in the absense of h-ydrostatic pressure, and this, whether the two liquids be miscible or not.* We may suppose that the attraction of the second liquid, of more -powerful affi. nity, which displaces the other, is equal to the pressure of the column of mercury required to force the latter through the porous substance. If we tie over one end of a cylindrical tube with a very thin membrane, saturated with concentrated brine by steeping 24 hours, and if we dry the' outer surface of the membrane carefully with bibulous paper, and now pour a few drops of pure water into the tube so as just to cover the inner surface of the membrane, the outer surface is seen in a few moments to be covered with minute drops of brine; that is, brine flows out of the pores of the bladder. A thick ox-bladder, saturated with oil, exhibits the same phenomenon in contact with water. The oil is expelled from the pores of the bladder by the water, which occupies its place. When the bladder is brought in contact with pure water, it takes up a certain quantity of that liquid. If its pores are previously filled with brine, and if we cover one side of it with pure water, the water mixes with'the brine in the pores of' the bladder; and on the side next the water there is -formed a diluted brine, which, being in contact with a stratum of pure water, mixes with it, and in this way the successive strata of water receive, from the bladder outwards, a certain quantity of salt. In the interior of the bladder, there are formed in like manner, towards the outer surface, mixtures of unequal saline strength. If we suppose the bladder to consist of several strata, all these strata receive, from the surface in contact with the water, a certain quantity of water; the outer stratum, in contact with the air, receives least, and is the most highly charged with salt. The cause of mixture is the cheminal affinity of the salt for the newly-added particles of water; this affinity is equal on both sides, but the attraction of the substance of the bladder is stronger for the more aqueous or less saline liquid, than for the more concentrated. In consequence of this difference in the attraction of the liquids for the substance of the bladder, a part of the mixture is displaced from the bladder; the less saline liquid takes the place of the more saline; a part of the latter is expelled, and, with it, a part of that water which has been added to the outer stratum by mixture. Brine and water flow' out in the direction of least resistance. The efflux towards the side on which the pure water was poured is prevented by the more watery liquid for the substance of the bladder. If we remove from the outer surface of the bladder the displaced saline liquid (which has been mixed with some water,) and put stronger brine in its place, and if on the opposite side we remove the very diluted solution, replacing it by a still more diluted one, the same process is repeated. There arises a permanent difference, and a state of mixture -and efflux continues till the liquids on the opposite surfaces of the bladder have the same, or very nearly the same, composition. If we suppose, that the two liquids moisten the bladder unequally, it follows, * One liquid expels another from a membrane. 15 atoms of water must have moved past each other; but this is impossible, since 1 atom of salt requires 18 atoms of water for solution, (10 parts of salt to 27 of water.) The weight of the pure water in the outer vessel was 19-26 grammes; consequently, the weight of the brine was to that of the pure water as 1: 2-22. In another experiment, in which the weight of the. brine in the tube was to that of the water outside, as 1: 7-98; the tube gained 0-822 grammes in weight; the liquid in the tube contained at first 0-947 gramines of salt;, and 24 hours after, 0-148 grammes: hence, 1'621 grammes of water had entered, while 0'799 grammes of salt had passed out. For 1 atom of salt;, which passed from the tube with brine to the vessel with water, there passed'from the latter to the former rather more than 13 atoms of water; (for 58'6 parts, or 1 atom of salt, 118 parts of water.) ATTRACTION OF LIQUIDS FOR MEMBRANES. 27 that in addition to the chemical attraction which the dissimilar particles of the liquids have for each other, a new cause, namely, the strong attraction of one of them for the substance of the partition, is introduced, which accelerates their motion or passage, and must have this effect, that one of them flows out in larger quantity, in the same time, than the other. The experiments (Fig. 3) elucidate this process, and show besides, that the exchange of the two liquids on both sides of the bladder is essentially determined }by their unequal specific gravities.* As long as the difference, in their composition (which may here be measured by the specific gravity) is very great, the change of volume (increase of one and decrease of the other) takes place rapidly; but at last, when this difference becomes very small, the liquids mix without further visible change of volume, obvious]y, because the attraction of the bladder to the mixtures on the opposite sides does not perceptibly differ, although the specific gravities are.still somewhat unequal. In the ultimate result, the action of dissimilar liquids on the substance of animal tissues, in consequence of which their mixture is attended with a change of volume, appears to be equivalent to a mechanical pressure, which is stronger from one side' than from the other.t ffig. 9. $ If the tube (Fig. 9,) which is closed with bladder at its wide opening, be filled with brine to the mark a, if so much mercury be then poured into the narrow vertical part as by its pressure to cause brine to begin to flow out in fine drops from the pores of the bladder, and if now, after removing so much of the nercury that the efflux is no longer visible, we place the apparatus in a vessel with pure water, colored blue, as in the figure, the mercury does not change its level; and when, after one or two hours, we carefully remove the tube from the water, we find that in the upper part of the wide end of the tube, which contained colorless brine, a dark blue stratum has been formed, which floats on a colorless liquid. After a longer time, the blue color spreads gradually downwards, till at last the brine acquires a uniform blue tint. It will readily be perceived, that the two liquids here mix, as if no pressure had been applied to the brine, for a mechanical pressure exerts. no influence on the mixture; but, in consequence of the pressure, the mixture takes place without change of volume. The mechanical pres- a.... sure which the water, in virtue of its stronger affinity for the bladder, exerts on the brine in the pores of the bladder, is held in equilibrium by the column of mercury, and the result is that exactly as much brine flows out as water flows in. ~ Let us suppose the column of mercury to be removed,,and the rise of the brine in the narrow tube is explained at once. If we close a short tube, filled with alcohol or brine,'with bladder at both ends'(an arrangement which may represent a cell,) and suspend it in a vessel of pure water, both surfaces of the bladder become convex outwards; they swell, but without bursting. As soon as the pressure, gradually increasing by the influx of water into the interior of the tube, is sufficient to keep in equilibrium the affinity of the water for the bladder, and consequently its further influx, the exchange goes on, for the future, without change of volume. Most porous bodies exhibit the phenomena described'in the preceding pages, if their pores are so minute that a- feeble hydrostatic pressure is-not propagated * Mixture is essentially determined by the unequal density of the liquids. f The action of two liquids on animal tissues equivalent to a mechanical pressure, unequal on opposite sides.: Experiment to show that an external pressure prevents change of volume. a Additional experiment. 28 MOTION OF THE JUICES OF THIE ANIMAL BODY. through them.* These phenomena may be produced with clay cells (1) (such as are used for galvanic apparatus;) with the lining membrane of the pods of peas and beans; with the fine inner bark of trees; with the skin of grapes, of potatoes, of apples; with the inner membrane of the capsules of bladder senna, &c.; but animal tissues surpass all others in efficacy. Besides their unequal affinity, they have an -unequal absorbent power for dissimilar liquids, by which their action in causing change of volume during mixture is strengthened. When a tube, closed with bladder, and filled with water, is immersed in alcohol or brine, there is produced at all points, where the brine or the alcohol comes in contact with bladder saturated with water, a change in the properties of the bladder.t When, in the open pores, the alcohol or brine mixes with the water already there, the absorbent power of the bladder for the water is diminished; a smaller volume of the mixture is retained than of pure water; that is to say, water flows' out in the direction of the alcohol or brine. This efflux is accompanied by a change in the volume of the substance of the bladder, for that side of it which is towards the alcohol or the brine contracts or shrinks. The opposite surfaces of an animal membrane, in contact with dissimilar liquids, for which they have unequal absorbent power, are in an unequal state of contraction. This condition is permauent, as long as the liquids do not change in their properties; but it ceases, in consequence of mixture, and is again restored, when, by means of the change of place in both the liquids which are in contact with the opposite surfaces of the bladder, the original or any other permanent inequality or difference of properties is produced. In all cases where a permanent change in the volume of two liquids, separated by a membrane, is observed during their mixture, it is always accompanied by a permanent difference in the nature or properties of the two liquids; and from this it follows, that the molecules of the animal membrane must be, during the mixture, in an alternate state of contraction and swelling, or dilatation; that is, in a continual motion.$ From what has been stated, it appears that the change of volume of two miscible liquids, separated by a membrane, is determined by the unequal capacity of being moistened, or the unequal attraction of the membrane for these liquids. The unequal absorbent power of the membrane for these liquids depends on the dissimilar nature of the liquids or of the substances dissolved in them. An unequal proportion (l) I consider it of sufficient importance to state here that porous clay also takes up unequal volumes of brine and water. In special experiments made on this subject, cells of clay (moderately ignited porcelain biscuit) were laid for 24 hours in pure water, then carefully dried externally with bibulous paper, and the increase in weight, that is, the weight of the absorbed water, carefully determined.~ The clay was then carefully dried, laid for 24 hours in brine, and the weight of the absorbed brine determined in like manner. In a second series of experiments, the clay cells were steeped in water and brine, and placed in the receiver of the air-pump, under a pressure of 8 lines of mercury (- of an inch) for 24 hours. Under the ordinary pressure, and in air the cells absorbedWeight. Volume. Water. Brine. Water. Brine 100 parts of clay cell........ I.-15'4 14'6 15'4 12' 2 11. —8 11' 8 11 11 8 9'7 In vacuo the- cells of clay absorbedWeight. Volume. Water. Brine. Water. Brine. 100 parts of clay cell absorbed I. —16'5 16'8 16'5 14'0 II. -13'8 13'8 13'8 11'5 * Porous bodies in general exhibit similar phenomena. t Bladder shrinks in contact with brine or alcohol. Change of volume in two liquids, separated by membrane, is accompanied by continual motion in the particles of the membrane; and depends on the unequal attraction of the membrane for the liquids., a Amount of liquids absorbed by porous baked clay. EXAMPLES OF CHANGE OF VOLUME IN LIQUIDS. 29 of the same dissolved matters (unequal concentration,) acts in many cases, just as if the liquids contained dissimilar substances. Although the experiments hitherto instituted, and the results obtained by FISCHER (who first observed these phenomena,) MANGUS, DUTROCRET, and others, admit of no comparison, since the apparatus used by them showed only relative change of volume, yet a knowledge of some of these results is, nevertheless, of importance. When the two liquids are, diluted sulphuric acid (of sp. g. 1'093) and water, the acid, at 50~ F., increases in volume i but if the acid have the specific gravity 1'054, the volume of the water-increases,* Diluted tartaric acid (11 parts of the crystalized acid and 89 of water) and water mix through a bladder without change of volume; with more than 11 per cent. of acid, the volume of the acid increases; with less that' of the water. Solutions of animal gelatine, gum, sugar, and albumen increase in volume when separated by a bladder from water; and the increase of volume in these different solutions, although of the same specific gravity, is very different indeed. When the specific gravity is 1'07, the increase in volume of the solution of gelatine amounts to 3, that of solution of gum to 5, of sugar 11, of albumen 12. When a solution of sugar (1 part of sugar to 16 of water) is separated by a bladder from water, it increases in volume; but if we add 1 part of oxalic acid, to the sugar, the water, on the contrary, increases in volume. If the amount of sugar in the solution be doubled, the liquids mix without change of volume. A solution of sugar, separated by bladder from one of oxalic acid, rises, in the same time, 3 times higher than when separated from water. (DUTROCHET.) From these experiments we obtain, as a universal result (which, however, requires confirmation,) that an animal membrane possesses a less power of absorption for solution of albumen than for all other organic substances:t and that a small amount of mineral or organic acids increases the power'transudation of water as well as of the solutions of many organic substances.4(1) The rapidity of mixture, of two liquids, separated by a membane, depends on the thicknes of the membrane, and stands in direct proportion to the velocity with which the mixture formed in the pores and on both surfaces of the bladder changes its place, and the original difference in the quality of the-two liquids is renewed.~ II If we suppose a tube, formed of a membrane (an intestine, for example,) and filled with water, ind if we assume that a current of saline solution flows round this tube, in consequence of a mechanical force, the increase of volume of the brine (the passage into it of a certain amount of water) will be effected in a far shorter time than if the brine were not in motion. The velocity of transference will diminish with the amount of difference in properties between the two liquids (the different amount or per centage of salt;)~ it will be greatest at first, and diminish as the dilution of the brine increases, in proportion, that is to say, as water is transferred from the contents of the'tube to the liquid without. The greatest effect, therefore, must occur and be permanent, when the water transferred to the brine is continually again removed from it, that is, when the concentration of the brine is kept uniform.?* To this end, if we suppose the membrane (')In order not to be misled in such experiments, we must avoid the employment of all those liquids which alter the membrane in its chemical properties. Such are, for example, acids of a certain concentration, nitrate of silver, salts of lead, chloride of gold, chloride of tin, chromic acid, bichromate of potash,' taunic acid, &c. Even in water, the properties of membranes generally undergo a change after some days, they then propagate a far weaker hydrostatic pressure through their pores, and are no longer fit for such experiments. * Examples of change of volume; in acids, and neutral organic substances, according to DUTROCHET t Membranes have a feeble power of absorbing solution of albumen. t Effect of adding acids. a Causes which influence rapidity of mixture. [I Motion of one of the liquids. ~ Difference in properties of the two liquids. os Effect of the continual removal of the transferred liquid analagous to suction. "30 MOTION OF THE JUICES OF THE ANIMAL BODY. to be difficultly permeable for one liquid, while the other is easily taken up into its pores, and if we reflect, that this second liquid, on entering into the pores of the bladder, in virtue of the attraction of their walls for it, acquires a certain velocity which permits it to pass beyond the extremitiss of the canal or the pores, so as to entirely fill the pores, and to come in direct contact with the liquid on the outside of the pores, it follows, that, when this second liquid moves past the poses with a certain velocity, the absorbed liquid must follow it during the mixture, and there must take place a rapid transference of the second liquid to the first, a true suction as if by a pump. The animal body is an example of an apparatus of this kind in the most perfect form.* The blood vessels contain a liquid, for which their walls are, in the normal state, far less permeable than for all the other fluids of the body. The blood moves in them with a certain velocity, and is kept at all times in a nearly uniform state of concentration by a special apparatus, namely, the urinary organs. The whole intestinal canal is surrounded with this system of blood vessels, and all the animal fluids, in so far as they are capable of being taken up by the parietes of the intestinal canal, and of the blood vessels situated around it, are rapidly mixed with the blood.t The volume of the blood increases, if no compensation is effected by means of the kidneys: and the intestine is enmptied of the liquids contained in it. The intestinal glands, through which this transference is effected, and each of which represents a similar apparatus of suction, contain, within them, two systems of canals, —blood vessels and lacteals; the blood vessels are placed next to the external absorbent surface, the lacteals chiefly occupy the central pait of the gland. The liquids circulating in these two systems have very unequal velocities, and as the blood moves much faster in the blood vessels, we perceive how it happens, that the fluids of the intestine are chiefly (in quantity and in velocity) taken up into the circulation. The difference in the absorbent power of the parietes of the intestinal canal for liquids which contain unequal amounts of dissolved matters, is easily observed in the effects produced on the organism by water and saline solutions.$ If we take while fasting, every ten minutes, a glass of ordinary spring water, the-saline contents of which are much less than those of the blood, there occurs, after the second glass (each glass containing 4 ounces,) an evacuation of colored urine, the weight of which is very nearly equal to that of the first glass; and after taking, in this way, 20 such glasses of water, we have had 19 evacuations of urine, the last of which is colorless, and contains hardly more saline matter than'the spring water. If we make the same experiment with a water, containing as much saline matter as the blood (4 to 1 per cent. of sea salt,) there is no unusual discharge of urine, and it is difficult to drink more than three glasses of such water. A sense of repletion, pressure, and weight of the stomach point out, that water as strongly charged with saline -matter as the blood requires a longer time for its absorption into the blood vessels. Finally, if we drink a solution containing rather more salt than the blood, a more or less decided catharsis ensues.~ The action of solution of salt is of three kinds, according to the proportion of salt. Spring water is taken up into the blood vessels with great rapidity; while these vessels exhibit a very small power of absorption for water containing the same proportion of salt as the blood does; and a still more strongly saline solution passes o'ut of the body —not through the kidneys, but through the intestinal canal. Saline solutions and water, given in the form of enemata, exhibit similar phenomena in the rectum.ll Pure water is very rapidly absorbed, and excreted * This occurs in the animal body. f Absorption of the liquids of the intestines into the blood. $ Effects produced by -drinking water and saline solutions. a Solution containing more salt than the blood. Enemata of water and saline solutions. INFLUENCE OF THE MEMBRANES ON THE SECRETIONS. 31 through the urinary passages. If we add to the water colored or odorous matters, these appear, more or less changed in the urine. When a small quantity of ferrocyanide of potassium is added, its presence in the urine is very soon detected by chloride of iron, which forms with it Prussian blue. Of concentrated solutions far less is absorbed in the same time, than of diluted; in most cases they mix with solid matters collected in the rectum, and are- expelled in the form of a watery dejection. All salts do not act alike in this respect. In equal doses, the purgative action of Glauber salt and Epsom salt is far stronger than that of sea salt; and their power of being absorbed by animal membranes appears to be in the inverse ratio of this effect. It is hardly necessary, particularly to point out that an explanation of the action of purgatives in general cannot be included in the above-described action of saline solutions on the organism. The example which has been given is intended to illustrate a physical property common to a large number of salts, and apparently of the nature of the acid or base of the salt; for chloride of calcium, chloride of magnesium, bitartrate of potash, tartrate of potash and soda, phosphate of soda, and certain doses of tartar emnetic, show the same action as sea salt, Glauber salt, and Epsom salt, although the bases and acids in these different salts are not the same. Solutions of cane sugar, grape sugar, sugar of milk, and gum, exhibit, when separated from water by an animal membrane, phenomena similar to those exhibited by the above-named solutions of mineral salts, without causing in the living body a purgative action, when of equal concentration.. The cause of this difference may be that the mineral salts, in their passage through, the intestinal canal, and through the blood, are not essentially altered in their composition, while these organic substances, in contact with bhe parietes of the stomach, and under the influence of the gastric juice, sutiffer a very rapid change, by which the action which.they have out of the body is arrested. Since the chemical nature and the mechanical character of mebranes and skins exert the greatest influence on the distribution of the fluids in the animal body, the relations of each membrane presenting any peculiarity of, structure, or of the different glands and systems of vessels, deserve to be investigated by careful experiment;* and it might very likely be found that in the secretion of the milk, the bile, the, urine, the sweat, &c., the membranes and cell-walls play a far more important part than we are inclined to ascribe to them; that besides their physical properties, they possess certain chemical properties, by which they are enabled to produce decompositions and combinations, true analyses; and if this were ascertained, the influence of chemical agents, of remedies, and of poisons on those properties, would be at once explained. The phenomena described in the preceding pages are observed, not in the gelatinous tissues alone, but also, apparently, in many other structures of the animal body, which cannot be reckoned as belonging to that class.t If we tie moist paper over the open end of a cylindrical tube, and, after pouring in above the paper white of egg to the' height of a few lines, place that end of the tube in boiling water, the albumen is coagulated, and when the paper is removed, we have a tube closed with an accurately fitting -plug of coagulated albumen, which allows neither water nor brine to run through.$ If the tube be now filled to one-half with brine, and immersed in pure water, as in Fig. 4, the brine is seen gradually to rise; and in three or four days it increases by from 4 to 2 of its volume, exactly as if the tube had been closed with a very thick membrane InJfuence of the cutaneous evaporation on the motion of the fliuids of the animal body.;When a tube about 30 inches long, bent in the forin of a knee, and widened at one end, is tied over at that end with a piece of moist ox-bladder, the bladder now * Influence of membranes on secretions. t These phenomena not confined. to the gelatinous tissues. A Coagulated albumen acts like a thick membrane. 32 MOTION OF THE JUICES OF THE ANIMAL BODY. thoroughly dried,, and the tube filled with mercury and inverted, so that the open, narrow end stands in a cup of mercury, the mercury in the tube falls to about 27 inches (Hessian,) and remains, if the bladder have no flow, at that height, rising and falling as the mercury does in a barometer. No air passes through the dry bladder into the Torricellian vacuum thus produced. When, by proper manipulation, we have allowed to pass out as much as can be removed of the air still contained in the tube, we have, in this arrangement, a barometer, containing no more air than would be found in one made with a similar tube hermetically sealed at the wide end, provided the mercury in the latter had not been boiled in the tube to expel the last traces of air. By the desiccation of the bladder, its pores, which allowed a passage to water, brine, oil, or even mercury, have obviously been closed by the adhesion of the successive layers of membrane, which perhaps cross each other, so that the bladder is not more permeable for the particles of air than a slice of horn of the same thickness. Jig.E 10. If we introduce water into the tube in the position, Fig. 10, to the line marked b, and, after fill- Fig 11. ing the narrow part of the tube with mercury, invert it in a -vessel of mercury, Fig. 11, we observe a number of minute bubbles of air passing through the moist bladder into the tube. The mercury falls to a certain point, which is higher or lower according to the thickness of the bladder; it standls at a lower level with a thin membrane than with a thick one.'When a single layer of ox-bladder is used, it falls to 12 inches (above the level of the mercury in the vessel;) with a double layer it stands at from 22 to 24 inches. If we take care to allow the water standing above the mercury to enter the wide part of the tube, so that the bladder is kept at all times covered with water, the mercury remains stationary at the same level. If, for example, it stood at 12 inches,, it remains there, although the quantity 3__ of water is constantly diminishing by evaporation from the bladder; and it maintains its level, even after all the water has disappeared. The height of the mercury in the narrow tube is an exact measure of the pressure acting on the surface of the bladder. The pressure in the inside of the tube is less than the existing pressure of the atmosphere outside by the height of that column of mercury. This difference of level between the mercury in the vessel and that in the tube is the limit of the pressure, under which air passes into the water through the pores of the bladder; or under which the molecules of water in the pores are displaced by the molecules of air. If we fill the tube entirely with water, and place the narrow end in mercury, while the wide end, closed with bladder, is exposed to the air, the mercury rises in the narrow limb, and at last reaches a point, identical with that to which it fell in the preceding experiment. For each specimen of bladder, according to its thickness, the level to which the mercury reaches is of course different. When the-diameter of the wide part of the tube, which is closed with bladder, is 12 millimetres, and that of the narrow tube 1 millimetre, the mercury rises, with ox-bladder, according to the temperature and the hygrometric condition of the air, to from 22 to 65 millimetres in one hour. The cause of the rise of the mercury in this experiment hardly requires a special explanation. The bladder is penetrated with water, covered on one side with water, and on the other in contact with a space (the air) not saturated with aqueous vapour. The water contained in the pores of the' side of the bladder turned towards the air ATMOSPHERIC PRESSURE ON THE LEVEL OF THE MERCURY. 33 evaporates; the space which it had occupied in the pores is filled with successive portions of water from within, in virtue of the attraction of the substance of the pores for water. The volume of the water in the tube diminishes, and thus a vacuum. arises, in which the mercury is forced to rise by the atmospheric pressure. The space formerly occupied by the water which has evaporated is now filled with mercury. When the mercury has reached a permanent level, the external pressure, which acts on the water in the pores of the bladder (and which tends to displace the particles of water) is obviously equal, before air enters, to the attraction which the substance of the bladder has for the particles of water, and these last to each other. Were the attraction less, air would enter, and the particles of water could not maintain their position. The rise of tle mercury, or its motion towards the surface of the bladder, that is, towards the point where evaporation is going on, is the result of a difference of atmospheric pressure, determined by the evaporation of the water, or of the liquid which penetrates through the bladder, and by the absorbent -power of the bladder for that liquid. One chief condition of the efficiency of a bladder, in regard to the rise of a coulmn of liquid, is, that it is kept constantly in contact with the liquid, for without this contact the absorbent power cannot manifest itself. By the evaporation a continual efflux of water, in the form of vapour, towards the side on which the air lies, is produced; and by the capillary action of the bladder on the other side, water is absorbed and retained with a force which counterpoises 12 or more inches of mercury, according to the thickness of the bladder. Now, since the rise of the mercury is an effect of the atmospheric pressure, it is plain, that the height to which the mercury rises, must depend to a certain degree on the state of the barometer.* In a tube filled with water, and closed with bladder, the absorbent force of which is equal to the pressure of a column! of 12 inches of mercury, the mercury rises by evaporation to the height of 12 inches, as long as a column of 12 inches of mercury can be sustained by the external atmospheric pressure. If this external pressure fall below that limit, the mercury in the evaporation tube falls to the same extent, and if there be water above the mercury, this water separates from the bladder. This property of bladder, therefore, would appear unaltered at an elevation' at which the barometer should stand at 12 inches; at a still greater elevation, on the contrary, the liquid would separate from the bladder. The external pressure has no influence on the amount of the water evaporating in the pores of the bladder; that'amount depends on the hygrometric state of the surrounding air, and, on the temperature.t In a rarified air, (provided it can take up moisture,) evaporation goes on more rapidly than in a denser air; and hence it is clear, that at certain elevations, the effect of-the bladder on the level of the liquid is more quickly produced than at the level of the sea. The amount of'. water which evaporates is directly propertional to the surrounding space, and to the temperature and corresponding tension of the liquid. When the tube; Fig. 10, is filled with water to b, then entirely filled with mercury and inverted in mercury, the Fig. 10. mercury, as we have seen, assumes a fixed level.: If we now keep the upper or wide end of the tube, which is closed with bladder, immersed in a vessel of water, Fig. 12, we shall find, after a short time, that the mercury sinks in the narrow tube. If its level has been 12 inches above that of the mercury in the vessel, it sinks when the bladder is put into water, 3 or 4 inches for example, and remains stationary at 8 or 9 inches, without sinking further for the next 12 hours. * Influence of the state of the barometer t The pressure of the air does not affect the amount of evaporation. 5 34 MOTION OF THE JUICES OF THE ANIMAL BODY. The sinking of the mercury is caused by water being forced through the bladder into the tube, in virtue of the existence of an external pressure greater than the pressure on the inside of the tube. ~ To displace the aqueous particles in the pores of the bladder by other aqueous particles, requires obviously a much smaller pressure than is necessary to displace them by particles of air.* In the one case, where both surfaces of the bladder are in contact with the liquid, the attractive force (that of the bladder for the water and of the water for the bladder) is equal on both sides; but not so in the other case, where one side of the. bladder is in contact with air. If the bladder had the same absorbent' power for the particles of air as for those of water, the particles of air and water would pass through the bladder under the same pressure; the experiment shows, that the absorbent power and permeability of the bladder for air is far less than for water. Hence,' it comes to pass, that when, with a given portion, of bladder, in the apparatus Fig. 11, mercury is raised by evaporation to a heighth of 12 inches, less than 12 inches of mercury are required, in the apparatus, Fig. 1, to cause water to pass through the bladder. ig. 13. t When the tube, (Fig. 13,) is filled with water, closed with bladder at both ends, and exposed to evaporation, the bladders in a short time become concave, that is, they are pressed inwards. As the evaporation of' the water through the moist surfaces of the bladder proceeds, there is formed in the upper part of the tube a vacuum, which is filled with aqueous vapor, and which continues to - increase. The place of the water which evaporates is, as in the experiments previously described, gradually occupied by air, which lllenters the tube through the bladder. It is evident, that when air enters the tube, (Fig. 13,) the pressure on the surface of the bladder is equal to the absorbent force of that bladder for the water. In the apparatus, Fig. 11, with the same bladder, the mercury might have been raised, in consequence of the evaporation, to a height of 4, 6, 12, or more inches, according to the thickness of the membrane. When the longer limb of the bent tube, after it has been filled with water, and closed at both ends with bladder, is placed in a vessel containing brine, and exposed to evaporate in the air, as in Fig. 14, it is plain, that when the atmospheric pressure, increasing in consequence of the evaporation of the water on both the surfaces of the bladder, reaches the point at which the brine flows through the pores of the bladder, then the place of the water which evaporates is occupied by brine. In fact, when the brine is colored blue, we observe, after a few hours, that a blue stratum forms within the tube, which constantly increases, till at last the vessel of brine is emptied, and the tube is entirely filled with brine. If the longer limb be immersed in bile instead of brine, the tube fills with bile, and if we employ, for closing one end, a membrane rather thinner than we use for-the other, from which the evaporation takes place, and then place the end with the thinner membrane in oil (oil of marrow,) the tube gradually fills with oil. In all these cases, no air enters the tube, which continues full of liquid, as it was at first. $ If we connect the evaporation tube by collars of caoutchouc with short bits of tube (Fig. 15,) full of water, and tied with bladder at both ends; and if we immerse the last bit of tube in brine, urine, oil, &c., all these cells, and at last the s Water passes through moist bladder more easily than air does. F Experiments with a tube closed at both ends with bladder: with one end in brine, the tube being filled with water, with one end in bile, and in oil. I Effect of a s4 ries of short tubes, closed at m)th ends with bladder. IMPORTANCE OF THE CUTANEOUS TRANSPIRATION. 35 Fig. 15. evaporation tube itself, become gradually filled with brine, urine, oil, &c.. The most general expression for these experiments and results jlf'K is this - that all liquids which are in connection with a mem-,! | l lf/-!l brane from the surface of which evaporation can take place, must lllll acquire motion towards that membrane. The amonnt of this motion is directly proportional to the I },jh J rapidity of evaporation, and consequently to the temperature and hygrometric state of the atmosphere. That'the skin of animals, and the cutaneous transpiration, as well' as the evaporation from the internal surface of the lungs, exert an important influence on the vital processes, and thereby on the state of health, has'been admitted by physicians ever since medicine has existed; but no one has hitherto ascertained precisely in what way this happens.t From what has gone before, it can hardly be doubted, that' one of the most important functions of the skin consists in the share which it takes in the motion and distribution of the fluids of the body.~ The surface of the body of a number of animals consists of a covering or skin permeable for liquids, from which, when, as in the case of the lung, it is in contact with the atmosphere, an evaporation of water, according to the hygrometric state and temperature of the air, constantly goes on.~ If we now keep in mind, that every part of the body has to sustain the pressure of the atmosphere, and that the- gaseous fluids and liquids contained in the body oppose to this pressure a perfectly equal resistance, it is clear that, by the evaporation of the skin and lungs, and in consequence of the absorbent power of the skin for the, liquid in contact with it, a difference in the pressure below the surface of the evaporating skin occurs. The external pressure increases, and in an equal degree the pressure from within towards the skin. If now the structure of the cutaneous surface does not permit a diminution of its volume, a compression (in consequence of the loss of liquid by evaporation,) it is obvious that an equalization of this difference in pressure can only take place from within outwards; first from within, and'especially from those parts which are in closest contact with the atmosphere, and which offer the least resistance to the action of the external'pressure. l Hence it follows, that the fluids of the body, in consequence of the cutaneous and pulmonary transpiration, acquire a motion towards the skin and lungs, which must be accelerated by the circulation of the blood. By this evaporation, the laws of the mixture of dissimilar liquids, separated by a membrane, must be essentially modified.T The passage of the food dissolved in the digestive canal, and of the lymph into the blood vessels, the expulsion of the nutritive fluid out of the minuter blood vessels, the uniform distribution of these fluids in the body, the absorbent power of the membranes and skins, which, under the actual pressure are permeable for the liquids in contact with them, are under the influence of the difference in the atmospherical pressure, which is caused by the evaporation of the fluids of the skin and lungs. The juices and fluids of the body distribute themselves, according to the thickness of the walls of the vessels, and their permeability for these fluids, uniformly through the whole body; and the influence which a residence in dry or in moist air, at great elevations or at the level of the sea, may exert on the health, in so far as the evaporation may thus be accelerated or retarded, requires no special explanation; while on the' other hand the suppression of the cutaneous transpiration must ~Liquids move towards the membrane from which evaporation takes place. Influence of the skin and cutaneous transpiration on health.: The cutaneous evaporation has an important share in causing the motion of the animal fluids. 0 Evaporation is constantly going on from the skin and lungs. 1I This evaporation must produce unequal pressure, by which the fluids acquire i w:tion towards the skin and lungs. ~ The change of pressure influences the mixture of the fluids. 36 MOTION OF THE JUICES OF THE ANIMAL BODY. be followed by a disturbance of this motion, in consequence of which the normal process is changed where this occurs. The pressure, which, in consequence of the evaporation, urges the fluids within the body to move towards the skin, is, as may readily be understood, equal to the difference of pressure acting on the surface of the skin.* From the experiment, Fig. 13, it is plain, that when one of the two surfaces of bladder at the ends of the tube Fig. 12, is exposed to atmospheric evaporation, while the other end is moistened with water, brine, or oil, these liquids are rapidly absorbed by the membrane, that is, are forced in by the external atmospheric pressure, and it is not less obvious, that the same thing takes place with the liquid with which one of the two evaporating surfaces has been moistened in the middle only; while the evaporation continues around the moistened spot. If, therefore, we moisten with a liquid the surface of the evaporating skin at any point,. the liquid is forced inwards by the external pressure.t Let us suppose any part of the skin to be rubbed with fat, the transpiration ceases at that part.: If now the skin around the part is in its normal activity, if, therefore, in the surrounding parts liquid is constantly passing off by evaporation, the fat must be urged, by the unequal pressure thus arising, towards these parts, or it is absorbed, just- as water, in the apparatus, Fig. 12, is absorbed, when in consequence of evaporation a difference between the internal and external pressure has arisen. If the whole skin were covered with fat, the absorption would be effected by the pulmonary evaporation. The blistering of the skin, and the sun-burning, to which men are exposed at great elevations, arise from the extraordinary dryness o.f the air, the increased evaporation, and the pressure by which the fluids filling the vessels are forced towards the surface,. Several causes contribute jointly to the appearance of the sweat, to the efilux of fluid, from the pores of the skin. One of these obviously depends on the velocity, which the fluid set in motion by evaporation or by a mechanical cause, acquires from the accelerated motion of the blood. In consequence of this velocity, the fluid moves out beyond the limits of the absorbing membrane or skin. The changes of the vital process, caused by the. unequal distribution of fluid in the body in consequence of evaporation, are best seen in animals which live in water, in whom, therefore, the above explained cause of motion- in the normal state does not act. When a fish is held immersed in water, so that the head is out of the water, while the rest of the body is covered, it dies in a few minutes.~ It dies exactly in the same way when head and gills are held in the water, and the body.in air (MILNE EDWARDS;) in both cases, without loss of weight. This fact shows that even if the weight of the animal be kept unaltered by the absorption of water through the body kept in that medium, yet the distribution of the fluids in the body does not take place in the proportion necessary for the preservation of their vital functions. - The fish dies. It is hardly necessary to remind the reader, that the experiments described in the foregoing pages, in so far as they permit us to draw conclusions as to the cause of the motion of the juices of the animal body,-agree in all respects with the observations made on plants by STEPHEN HALES more than 120 years since.ll The experiments of HALES on the mechanism of the. motion of the sap, may stand as a pattern to all times of an excellent method. That they remain, to this moment, unsurpassed in the domain of vegetable physiology, may be, perhaps, explained by the fact that they date from the age of NEWTON. They ought to be familiar to every vegetable physiologist In the beginning of his work, HALES describes the experiments which he made * The force urging the fluids towards the skin is equal to the difference of pressure acting on the skin. t Liquids placed on the skin are absorbed by the evaporatiou of other parts. t Effect of rubbIng fat on a part of the skin or on the whole of it. a Fishes die in %ar, because the distributioi of the fluids is prevented. I XlperimAunts ot HALLS on the motion of the sap in plants. EXPERIMENTS ON THE MOTION OF THE SAP OF PLANTS. 37 on the motion of the sap in plants in consequence of their evaporation in branches covered with foliage, in cut plants as well as in those still provided with roots. He shows by the following experiment the influence of the mechanical pressure of a column of water, with and without the help of evaporation. To a branch of an apple tree bearing its twigs and leaves, HALES fastened, airtight, a tube seven feet long. He kept the branch with its twigs and leaves immersed in a large vessel of water, and filled the tube with water. By the pressure of the column of water, water was forced into the branch, and in two days the water in the tube had sunk 14~ inches. On the third day, he took the branch out of the water, and exposed it to free evaporation in the air. The water in the tube fell, in twelve hours, 27 inches. To compare the force with which water is driven through the vessels of the wood, by pressure alone, with that produced by pressure and evaporation, he joined an apple branch, 6 feet long, with leaves, and exposed to- the air, with a tube 9 feet long, which was filled with water. From the pressure caused by the column of water, and by the evaporation going on at the surface of the twigs and leaves, the water fell (XIth experiment,) in one hour, 36 inches. He now cut off the branch 13 inches below the tube, and placed the portion cut off (with the twigs, and leaves) vertically in a vessel of water. This last absorbed, in 30 hours, 18 ounces of water, while the portion of wood remaining in connection with the tube, which was 13 inches long, only allowed 6 ounces of water to pass, and that under the pressure of a column of 7 feet of water. HALES shows in three other experiments, that the capillary vessels of a plant, alone, and ini connection with the uninjured roots, are easily filled with water by capillary attraction, without, however, possessing the power of causing the sap to flow out and to rise in a tube attached.* The motion of the sap, concludes HALES, belongs to the evaporating surface alone; he proves that it goes on in an unequal degree from the stem, the twigs, the flowers, and fruit, and that the effect of the evaporation stands in a fixed ratio to the temperature and hygrometic state of the air. If the air were moist, but little were absorbed; the absorption was hardly perceptible on rainy days. He opens the second chapter of his Statistics with the following introduction:"Having in the first chapter seen many proofs of the great quantities of liquor imbibed and perspired by vegetables, I propose in this, to inquire by what force they do imbibe moisture. Though vegetables (which are inanimate) have not an engine, which by its alternate dilations and contractions, does in animals, forcibly drive the blood through the arteries and veins; yet has nature wonderfully contrived other means, most powerfully to raise and keep in motion the sap. In his experiment XXI., he exposed one of the chief roots of a pear tree in full growth at a depth of 21 feet, cut off the point of it, and connected the part of the root left in connection with the stem with a tube which he filled with water and closed with mercury. In consequence of the evaporation from the surface of the tree, the root absorbed the water in the tube with such a force, that in six minutes the mercury rose to 8 inches in the tube. This corresponds to a column of water 9 feet high. This force is nearly equal to that with which the blood moves in the great femoral artery of the horse. HALES, in his experiment XXXIV., found the force of the blood in various animals; " By tying those several animals down alive upon their backs, and then laying open the great left crural artery, where it first enters the thigh, I fixed to it (by means of two brass pipes which run one into the other) a glass tube of above.10 feet long, and 8th of an inch in diameter in bore. In which tube the blood of one horse rose 8 feet 3 inches, and the blood of another horse 8 feet 9 inches. The blood of a little dog 6' high." HALES showed by special experiments, that the absorbent force which he pointed out in the root is found also in the stem, in each separate twig, each leaf, and every part of the surface; and that the motion of the sap continues from the root towards * The motion of the sap is caused by the evaporating surface. 38 MOTION OF THE JUICES OF THE ANIMAL BODY. the twigs and leaves, even when the stem has been entirely stripped of bark, inner and outer. This force acts not only from the roots in the direction of the summit but also from the summit in the direction of the root. From his experiment he deduces the presence of a powerful attractive force residing in every part of the plant. We now know, that this attractive force, as such, did not cause the rise of the mercury or water in his tubes, and it appears clearly from his experiments, that the absorbent power of plants, of each leaf, of each fibre of the root, is sustained by a powerful external force which is nothing else than the pressure of the atmosphere. * By the evaporation of water at the surface of plants, a vacuum arises within them, in consequence of which water and matters soluble in water are driven inwards and raised from without with facility, and this external pressure, along with capillary attraction, is' the chief cause of the motion and distribution of the juices.t With respect to the absorbent power of the plant for gases, under a certain external pressure, his experiments offer the most beautiful evidence.I HALEs says, in his experiment XXII., "This height of the mercury did in some measure show the force with which the sap was imbibed, though not near the whole force; for while the water was imbibing, the transverse cut of the branch was covered with innumerable little hemispheres of air, and many air-bubbles issued out of the sapvessels, which air did, in part, fill the tube e r, as the water was drawn out of it; so that the height of the mercury could only be proportionable to the excess of the quantity of the water drawn off, above the quantity of air which issued out of the wood. And if the quantity of air which issued from the wood into the tube, had been equal to the quantity of water imbibed, then the mercury would not rise at all; because there would be no room for it in the tube. But if 9 parts of 12 in the waterbe imbibed by the branch, and in the mean time, but three such parts of air issue into the tube, then the mercury must needs rise near 6 inches, and so proportionably in different cases." WThen, in his experiments, the root, the stem, or a twig had been injured at aniy part, by the cutting off of buds, root-fibres, or small twigs, the absorbent power of the remainder was diminished in a very obvious degree (because, from these places, by the entrance of air the difference of air was more easily equalized;)~ the absorbent power was greatest on freshly-cut surfaces, on which, however, it gradually decreased, till, after several days, it was not greater in these places than in the uninjured surface of the plant. The evaporation, further, argues HALES, is the powerful cause which provides food for the plant and its vicinity. Disease and death of the plant follow, when the proportion between evaporation and supply is interrupted or destroyed in any way.11 When, in hot summers, the earth cannot supply, through the. roots, the moisture which during the day has evaporated through the leaves and surface of the tree, when the tree, or a twig of it, dries up, the motion of the sap is arrested at these points. When once dried, capillary action alone cannot restore the original activity; the evaporation is the chief condition of the life of plants; by its means a permanent motion, a continually repeated change in the quality of the. juice (sap) is effected. "By comparing," says HALES, 6" the surface of the roots of plants, with the surface of the same plant above ground, we see the necessity of cutting off many branches from a transplanted tree: for if 256 square inches of root in surface was necessary to maintain this cabbage in a healthy natural state; suppose upon diggming it up, in order to transplant, half the roots be cut off (which is the case of most young transplanted trees,) then it is plain that but half the usual nourishment can be carried up, through the roots, on that account; and a very much less pro* The pressure rf the atmosphere is the active force. j A partial vacuum is caused within plants by evaporation. $ The surface of plants absorbs gases. The absorbent power diminished by injury to the plant. [I Evaporation provides food for the plant. OBSERVATIONS OF HALES ON THE BLIGHT IN HOPS. 39 portion, on account of the small hemisphere of; earth the new-planted, shortened roots occupy; and on account of the loose position of the new-turned earth, which touches the roots at first but in few points." HALES proves the influence of suppressed evaporation by the following observations on hop-vines. "Now there being 1,000 hills in an acre of hop-ground, and each hill having three poles, and each pole three vines, the number of vines will be 9,000; each of which imbibing four ounces, the sum of all the ounces, imbibed in an acre in a twelve hours' day, will be 36,000 ounces = 15,750,000 grains = 62,007 cubic inches, or 220 gallons; which divided by 6,272,640, the number of square inches in an acre, it will be found, that the quantity of liquor perspired -by all the hopvines, will be equal to an area of liquor, as broad as an acre, and T6r part of an inch deep, besides what evaporated from the earth. And this quantity of moisture in a kindly state of the air is daily carried off in a sufficient quantity to keep the hops in a healthy state; but in a rainy moist state of air, without a due mixture of dry weather, too much moisture hovers about the hops, so as to hinder in a good measure the kindly perspiration of the leaves, whereby the stagnating sap corrupts, and breeds mouldy fen, which often spoils vast quantities of flourishing hop-grounds." This was the case in the year 1723, when ten or fourteen days' almost continual rains fell, about the latter half of July, after four months' dry weather; upon Which the most flourishing and promising hops were all infected with mould or fen, in their leaves and fruit, whilst the then poor and unpromising hops escaped, and produced plenty; because they, being small, did not perspire so great a quantity as the others; nor did they confine the perspired vapor, so much as the large thriving vines did, in their shady thickets. This rain on the then warm earth made the grass shoot cut'as fast as if it were in a hot-bed; and' the apples grew so precipitately, that they were of a very fleshy constitution, so as to rot more remarkably than had ever been remembered."*' The planters observe, that when a mould or fen has once seized any part of the ground, it soon runs over the whole; and that the grass, and other herbs under the hops, are infected with it." " Probably because the small seeds of this quick-growing mould, which soon come to maturity, are blown over the whole ground. Which spreading of the seed may be the reason why some grounds are infected with fen for several years successively."; I have in' July (the season for fire-blasts, as the planters call them)' seen," says HAALEs,' the vines in the middle of a hop-ground all scorched up, almost from one end of a large ground to the other, when a hot gleam of sunshine has come immediately after a shower of rain; at which time the vapors are often seen with the naked eye, but especially with reflecting telescopes, to ascend so plentifully, as to make a clear and distinct object become immediately very dim and tremulous. Nor was there any dry gravelly vein in the ground, along the course of this scorch. It was, therefore, probably owing to the much greater quantity of scorching vapors in the middle than outsides of the ground, and that being a denser medium, it was much ho-tter than a more rare medium." " This is an effect which the gardeners about London have too often found to their cost, when they have incautiously put bell-glasses over their cauliflowers early in a frosty morning, before the dew was evaporated off them; which dew being raised by the sun's warmth, and confined within the glass, did- here form a dense, transparent, scalding vapor, which burnt and killed the plants." When these observations are translated into our present language, we perceive with what acuteness and accuracy HALES recognized the influence of evaporation on the life of plants. According to him the development and growth of the plant depends on the supply of nourishment and moisture from the soil, which is determined by a certain * Observa'ions of Hales on the blight i: hops and other plants. 40 MOTION OF THE JUICES OF THE ANIMAL BODY. temperature and dryness of the atmosphere. The absorbent power of plants-the motion of their sap, depends on evaporation; the amount of food necessary for their nutrition, which is absorbed, is proportional to the amount of moisture given out (evaporated) in a given time.'When the plant has taken up a maximum of moisture, and tha evaporation is suppressed by a low temperature or by continued wet weather, the supply of food, the nutrition of the plant, ceases; the juices stagnate, and are altered; they now pass into a state in which they become a fertile soil for microscopic plants. When rain falls after hot weather, and is followed by great heat without wind, so that every part of the plant is surrounded by an atmosphere saturated with moisture, the cooling due to further evaporation ceases, and the plants are destroyed by fire-blast or schorching (Sonnenbrand, German, literally, sun-burn or sun-blight.) After the experience and observations of so long a period in reference to the influence of evaporation on the condition of plants, I hardly think that any unprejudiced observer can entertain the smallest doubt concerning the cause of the great mischief which has befallen agriculture during the last few years.* If HALES, that unequalled observer and inquirer, had known the potato disease, I hardly'believe that he would have ascribed it to an internal cause belonging to the plant, any more than he thought of ascribing the blight of the hop plants, formerly mentioned, to a special hop disease, or the rotting of the apples to an apple disease. Even PARMENTIER, to whom France is indebted for the introduction of the potato, knew this disease, and has very accurately described it.t The term " potato-rot" has been known to the oldest peasants! and agriculturists since their youth; it has, doubtless, only acquired of late years the frightful significance, which seems to threaten the well being of nations, since the causes,, which formerly brought it locally into existence, have spread over whole districts and countries. The writings of HALES bring to our century from a preceding one the consoling certainty (and this is especially important,) that the cause of this decay is not to be looked for in a degeneration of the plant, but depends on the combination of certain conditions accidentally coincident; and that these, when they are well ascertained and kept in view, enable the agriculturist, if not to annihilate, at least to diminish, their hurtful influence.t The potato plant obviously belongs to the same class of plants as the hop plant, namely, to that class which is most seriously injured by the stagnation of their juices in consequence of suppressed transpiration.~ According to KNIIGIT, the tubers are not formed by swelling of the proper roots, but by the' development of a kind of underground stalks or runners. He found that when the, tubers under ground were suppressed, tubers were formed on'the-stalks above ground; and it is conceivable that every external cause which exerts a hurtful influence on the healthy condition of the leaves and stalks, must act in like manner on the tubers. In the districts which were most severely visited by the so-called potato disease in 1846, damp, cold, rainy weather followed a series of very hot days; and in 1847, cold and rain came on, after continued drought, in the beginning of September, exactly at the period of the most luxuriant growth of the potatoes.l] In most places, no trace of disease was observed in the early potatoes before the middle of August; and even after that period low-lying, cold and wet fields, were chiefly attacked by it. In many plants, in the same field, in which the seed potatoes had been destroyed by putrefaction and decay, the tubers appeared quite healthy, while in others it was easy to see that these tubers alone, which lay next to the,old potatoes, were infected and attacked by the disease, and that on the side next to the old tubers.T In 1840 all the potato plants in my garden died completely off towards the end of August, before a single tuber had been formed; and in 1847, in the same field, * The potato blight has probably a similar origin. t The potato blight, has been long known. $ It is not due to a degeneration of the plant, but to a combination of external causes.? The potato plant is one of those which suffers'most from suppressed evaporation. U Character of the weather in 1846 and 1847, when the potato blight prevailed. ~ In most places the early potatoes escaped till after the middle of August. EFFECT OF COLD ON PLANTS. 41 the tubers of all those plants which stood under trees, and in protected spots, were quite rotten, while no trace of disease appeared in spots which were more elevated and more fully exposed to the current of air. The cause of the disease is the same which, in spring and autumn, excites influenza; that is, the disease is the effect of the temperature and hygrometric state of the atmosphere, by which, in consequence of the disturbance of the normal transpiration, a check is suddenly, or for a considerable time, given to the motion of the fluids, which is one chief condition of life, and which thus becomes insufficient for the purposes of health, or even hurtful to the individual.*~ The whole existence of a plant, the resistance which it opposes to the action of the atmospheric oxygen, is most closely connected with the continued support of its vital functions. The mere alternation of day and night makes, in this respect, a great difference. The sinking of the external temperature by a few degrees, causes the leaves to fall in autumn; and a cold night is followed by the death of manyannual plants. If we reflect that a plant, in order to protect itself from external causes of disturbance, or to seek the food which it requires, cannot change its place; that its normal vital functions depend on the simultaneous and combined action of water, of the soil, of the external temperature, and of the hygrometric state of the atmosphere; that is, on four external circumstances; it is easy to comprehend thel disturbance of functions which must occur in the organism in consequence of any change in the mutual relations of so many combined agencies.t The state of a plant is a sure indication of equilibrium or misproportion in the external conditions of its life; and the dexterity of the accomplished gardener consists exactly in this, that he knows and can establish the just proportion of- these conditions for each species of vegetable. Only one of these numerous conditions is in the power of the agriculturist, and that is, the production of the quality of the soil appropriate for the crop, including the necessary modification of, its composition, by the mechanical working of the soil; by the irrigation or draining of the fields; and lastly, by the employment of manure. When one of the constituents of the soil, which,'under the given circumstances, is necessary for the support of the vital functions, is absent, the external injurious influence is strengthened by this deficiency. Had this constituent been present, the plant would have been enabled to oppose to the external hurtful influences a continued resistance. One day may be decisive as to the life or death of a plant.t An accurate knowledge of the influence exerted by the various constituents of the soil on the diseased condition, must enable the agriculturist to protect and preserve many of his fields for a long time from this destruction; but it is obvious that a universal remedy against this evil does not exist. When -the vessels of the plant are filled to overflowing with water, and the motion of the sap is suppressed, the nutrition, in most plants, is arrested, and death takes place. Every one knows the effect of a sudden or of a gradual overfilling of certain parts or organs, when the corresponding evaporation is suppressed. By the endosmotic pressure of the water flowing towards those cells, which contain sugar, mucilage, gum, albumen, and soluble matters in general, the juicy fruits and seeds approaching maturity burst, anid the juice of grapes, cherries, plums, &c., passes, on contact with the air, into a state of progressive change. The fungi which have been observed on the potato plants and the putrefaction of the tubers, are not the signs of'a disease, but the consequences of the death of the plant.~ Among the most important of the experiments made by Hales we must reckon undoubtedly those on the rise of the spring sap in perennial plants. His observations have been entirely confirmed by all those who since his time have studied the subject; but, in my opinion, without our having approached one step nearer to the cause of the phenomena. * The cause of potato blight is the same as that of influenza, and depends on the temperature and hygrometric state of the air. t The life of plants is dependent chiefly on four external causes: only one of. which, namely, the quality of the soil, in the power of the agriculturist. $ Effects of the presence or absence of a single constituent of the soil. a The plant dies, and fungi and putrefaction follow. 6 42 MOTION OF THE JUICES OF THE ANIMAL BODY. The most recent experiments on this subject by E. BRUCKE, leave no doubt in regard to, the actual state of our knowledge. According to DUTROCHET, it is the extremities of the radical fibres, called by DE CANDOLLE, spongioles, which effect the rise of the spring sap; and he believes (L'agent immediat du mouvement vital, Paris,1826,) that the force with which the sap is driven upwards, acts from the root. DuJTROCHET cut off a peice of a vine stem, two metres long; and he saw that the sap flowed steadily from the shortened stem in connection with the root. When he had again cut it off close to the ground, he observed the portion in the ground continued to pour f6rth sap from the whole cut surface. He pursued the experiment, going deeper every time, and he always found that the sap flowed from the part left in the ground, till at last he came to the extreme points of the fibres, in which he then located the origin of the moving force. The peculiar activity of the spongioles must, according to DUTROCHFT, be ascribed to all the causes, taken together, which determine the phenomena of endosmosis. Now that we are better acquainted with the phenomena of what is called endosmosis, we may oppose to this view some well founded doubts. All observers agree, that the increase in volume of a liquid, separated from another liquid by a porous diaphragm, is determined by a difference in the qualities of the two liquids. If their composition and properties be the same, there is no cause sufficent to produce mixture and change of volume, since in this case, the attraction of both for the diaphragm, and for each other, is perfectly equal. In the course of his admirable researches, BRIcKKE determined the specific gravity of the spring sap which had flowed from the vine.* He found it, in one plant, - l10008, and in another,- 1.0009.(1) These numbers prove irresistably, that in the specific gravity of the sap of the vine is in no way different from that of ordinary spring water, or of the water which has filtered through garden mould. In most cases, spring water contains even more dissolved matter. The spring sap of the vine, which had the sp. g.'10008, raised a column of mercury to the height of 174 lines (14.5 inches,) and therefore exerted a pressure equal to that of a column of water 195 inches high. It is quite impossible to account for this pressure by the difference in the amount of dissolved matter in the water absorbed by the roots, and the sap flowing from the cut surface. In the experiment No. IX., of BRUCKE, made with a vine, the sap of which had the sp. g. 1 0009 the mercury was raised at 7 A. M., to the height of 209 lines, (nearly 17'5 inches. No one can doubt that what is called endosmosis has some share in the rise of the sap of the maple and birch trees, which is proportionally rich in sugar, and differs materially in composition from spring water, as well as on the flow or exudation of gummy or saccharine juices; but the pressure exerted in these cases, cannot be compared to that exerted by the sap of the vine, where the causes included under the word endosmosis cannot act. It is evident, that the cause of the pressure of the spring sap must be transient, called into action by external causes, and limited to a short period.t The experiment of DUTROCHET, from which he concludes that the cause of the rise of the sap resides in the extreme points of the roots, may be thus interpreted: —" The cause of the efflux and pressure of the sap exists in all parts of the uninjured plant, down to the extreme spongioles of the root." The present season does not admit of experiments on this point; bult as spring approaches, it may be proper here to develope more clearly the grounds of the opinion, that the cause of the efflux of the sap of the vine is a transient one. Perhaps some one may thus be induced to decide experimentally all the questions of this remarkable phenomenon. (t) Poggendorf's Annalen der Physik, lxiii. 177. * Observations of BRUvcKE on the specific gravity of the sap of vines. t The cause of the rise of the sap is transient; and depends on external influences EXPERIMENTS OF HALES. 43 HALES, in his experiment XXXIV., cut off a vine stem 7 feet above the ground, and attached to the trunk tubes of 7 feet long, joined together. Below the cut there were no branches. This was done on the 30th of March, at 3 P.M. As the stem poured out no sap on that day, he poured water into the attached tube to the height of two feet, This water was absorbed by the stem, so that about 8 P.M., the water had fallen to 3 inches in the tube. The next day, 2 past 6 A. M., the sap stood 3 inches higher than at 8 the evening before. From this time the sap continued to rise, till it reached a height of 21 feet. It would perhaps, says HALES, have risen higher, had the joinings of the tubes been more water-tight. Whatever opinion we may entertain as to the-cause of the efflux and pressure of the sap, it is impossible to suppose that the mechanical or any other structure or quality of the radical fibres, the spongioles, or the inner parts of the vine stemn generally, can have changed so much between the evening of the 30th and the morning of the 31st, as to give rise to two completely opposite influences. On the evening of the 30th the water poured into the tube was absorbed; on the 31 st it was expelled with a continually increasing force. In his experiment XXXVII., HALES fixed, on three branches of a horizontally. trained espalier vine, siphon tubes, filled to a certain point with mercury. The three branches received their sap from the common stem, that stem from the root. The first branch was 7 feet'from the -second, the second 22 feet 9 inches from the third. The first and third branches were two years old, the middle one was older. From the 4th to the 20th of April, the mercury stood, in consequence of the pressure of the sap, higher in the open limb of the tubes than in the other which was attached to the branch. The greatest height attained by the mercury was from 21 to 26 inches'. On the 211st of April, when the flowering was nearly over, the sap in the middle branch went backwards; it was absorbed, and so considerably, that the mercury stood 4 inches lower in the open limb than in the other. After a rainy night on the 24th of April, the sap again rose in the open tube 4 inches. In the first (lowest) branch, the sap went back on the 29th of April, 9 days after the middle one; the third (highest) branch only began to absorb the sap on the 3d of May, thirteen days after the middle one. We see. from this experiment, as HALES observes, "That the cause which produces the flow of the sap does not proceed from the root alone, but that it belongs to a force inherent in the stem and branches. For the middle branch followed more rapidly the changes of temperature, of dryness and of moisture, than the two others, and absorbed the sap nine days before one, and thirteen days before the other, both of which, during this time, poured out sap instead of absorbing it. (The cause of the efflux and pressure had, in the older branch, disappeared, and given place to an opposite influence, while it still continued active in the two younger branches.) "' The middle branch was 3 feet 8 inches higher than that next the stem. The height of the mercury in the three tubes was, respectively, 141, 12k, and 13 inches. The maximum was 21, 26, and 26 inches. These numbers prove that the greater length of the middle branch had no perceptible influence on the height of the mercury, as compared with that in the other tube." In his experiment XXXVIII., HALES observes, —" Moisture and warmth made the sap most vigorous. If the beginning or middle of the bleeding season, being very kindly, had made the motion of the sap vigorous, that vigor would immediately be greatly abated by cold easterly winds.* "If in the morning while the sap is in a rising state, there was a cold wind with a mixture of sunshine and cloud; when the sun was clouded the sap would immediately visibly subside, at the rate of an inch in a minute for several inches, if the sun continued so long clouded; but as soon as the sunbeams broke out * Effect of cold and of shade on the rise of the sap. 44 MOTION OF THE JUICES OF THE ANIMAL BODY. again, the sap would immediately return to its then rising state, just as any liquor in a thermometer rises and falls with the alternacies of heat and cold; whence it is probable, that the plentiful rise of the sap in the vine in the bleeding season, is effected in the same manner." If we consider, that the sap in spring, even with a clouded sky, does not cease to rise and flow, for this even goes on during the night, we cannot explain the fall of the sap from the moment that the sun was covered by a cloud by a mere change of temperature in the juice, because the time was too short for the cooling and contraction by cooling (one inch in a minute.)* _ Heat determined the more rapid rise, and cold the fall, but they acted on a cause which lay higher than the root, and which was more sensitive to heat than the liquid itself. HALES says, in his experiment XXXVIII. —" In very hot weather many air bubbles would rise, so as to make a froth an inch deep, on the top of the sap in the tube.t " I fixed a small air pump to the top of a long tube, which had twelve feet height of sap in it; when I pumped, great plenty of bubbles arose, though the sap did not rise, but fell a little, after I had done pumping." In his experiment's on the amount of air absorbed by plants, chapter V., he observes, " in the experiments on vines, the very great quantity of air which was continually ascending. from the vines, through the sap in the tubes; which manifestly shows what plenty of it is taken in by vegetables, and is perspired off with the sap through the leaves." When we take these facts into consideration, the opinion appears not untenable, that the incomprehensible force, which causes the sap of the vine to flow in spring, may be simply referred to a disengagement of gas which takes place in the capillary vessels (filled with liquid, and keeping themselves constantly full,) in consequence of a kind of germination; and it is possible that the height of the column of mercury, or of water, is only a measure of the elasticity of the disengaged gas.: Let us suppose a strong glass bottle, in the mouth of.which a long tube, open at both ends, and reaching to the bottom, is cemented, to be filled with a liquid in which, from any cause, a gas is disengaged (solution of sugar mixed with yeast, for example,) it is evident that the liquid must rise in the tube from the separation of the gas. When it has risen to 32 feet, the gas will occupy only the half, and at 64 feet, one third of its volume under the usual atmospheric pressure. In this case, the height of the liquid in the tube is no measure of a special power residing in the walls of the vessel; it only shows the tension of the gas. If the walls of the vessel were permeable to the gas under a certain pressure, no furthler rise, beyond that point, could occur. If, in the apparatus, Fig. 4, we push the tube a through the cork down to the little lead drop; if we then fill the tube c with water to which some yeast has been added, and a with solution of sugar, and expose the whole to a temperature of from 68~ to 75~, the liquid rises in b, from the gas disengaged in c, very rapidly, so as to overflow. If c be filled with solution of sugar, and a with yeast, the same rise occurs, and lasts till the disengaged gas puts an end to the contact between the membrane and the liquid. It is hardly necessary to point out, that the idea above expressed as to the cause of the flow and pressure of the spring sap, is nothing more than an indication of the direction in which experiments must be made. When we know with accuracy the volume of the liquid which flows out of a vine at the time of flowering, and the quantity of gas which is developed at the same time, we shall, I trust, find ourselves a step nearer to the explanation of this phenomenon. According to the experiments of GEIGER and PROUST, the sap of the vine is rich in carbonic acid; and it is possible that the gas which is disengaged, may be no other than carbonic acid gas. * How is this effect to be accounted for? t Gas is given off with the sap. $ The rise of the sap may, therefore, be caused by th evolution of gas. APPENDIX. ON THE NATURE AND PREVENTION OF THE POTATO DISEASE. AFTER the preceding pages were in print, I received from Baron Liebig a copy of the Journal of the Agricultural Association of the Grand Duchy of Hesse, (Darmstadt,) No. 7, dated 15th February, 1848, containing the account of a method proposed by'Dr.-Klotzsch (Keeper of the Royal Herbarium, Berlin, and a distinguished Botanist and Vegetable Physiologist,) for preventing the ravages of the potato disease. The proposal of Dr. Klotzsch, and his views as to the nature of the disease,'are such as materially to strengthen the opinions expressed on this subject by Baron Liebig, (see pp. 87, seq.) As a knowledge of the method suggested by Dr. Klotzsch is likely to be interesting to many of the readers of this work, I have thought it right to give it in an Appendix. WILLIAM GREGORY. METHOD PROPOSED BY DR. KLOTZSCH, FOR THE PROTECTION OF THE POTATO PLANT AGAINST DISEASES. The potato, which is an annual plant, represents, in the tubers developed from the stem, the perennial part of a plant.~ For while the duration of its development is analogous to that of annuals, its functions coincide ~exactly with those of dicotyledonous shrubs and trees. "The potato plant differs from all those plants which are cultivated for economical purposes in Europe, and can only be compared to those orchideous plants which yield salep, and which are not yet cultivated among us. r" The tubers, both of the potato' and of the salep plants, are nutritious, and agree in this, that in the cells of the tubers, grains of starch, with more or less azotized mucilage, are collected, while the cell walls possess the remarkable property of swelling up into a jelly, and thus becoming easily digestible, when boiled with water. "But while the tuber of salep contains only one bud, or germ, the potato usually develops several, often many, germs. 6" The potato plant, like all- annuals, exerts its chief efforts in developing flowers and fruit. Like all annuals,:too, it-has the' power of shortening this period of development, when the power of the roots is limited; as also of lengthening it when the extent and power of the roots are increased. We observe in nature that plants with feebly developed roots often have a weak, sickly aspect, but yet come to maturity in flower -and fruit sooner than stronger individuals, well furnished with roots. (45) 46. APPENDIX. "In perennial plants we observe a second effort, which is directed towards preparing and storing up nutritious matter, for the consumption of the plant. The preparation of this nutriment is effected by the physiological action of the leaves, under the influence of the roots. The stronger and larger the former are, the more is this preparation of food delayed. "The nutritious matters are stored in the colored stratum of the bark in shrubs and trees, and in the tubers in the potato and salep plants. Not only, however, the nutrient matters, but also the cells, owe their origin to the physiological action of the leaves. "On considering these things, it follows, that the potato plant requires more care than is usually devoted to it. Hitherto the whole cultivation consisted in clearing off weeds, and hoeing up the earth round the stems. Both of these measures are, indeed, necessary, but they are not alone sufficient; for the plant is cultivated, not on account of its fruit, but for the sake of its tubers, and our treatment should be modified accordingly. "6 The chief points to be attended to, with a view to the attainment of this object, namely, the increase of tubers, are1. To increase the power in the roots, and 2. To check the transformation which occurs in the leaf. "We obtain both ends simultaneously, if, in the 5th, 6th, and 7th week after setting the tubers, and in the 4th and 5th week after planting out germs furnished with roots, or at a time when the plants reach the height of 6 to 9 inches above the soil, we pinch off the extreme points of the branches or twigs to the extent of half an inch downwards,* and repeat this on every branch or twig, in the 10th and 11th week, no matter at what time of day. "The consequences of this check to the development of the stem and branches, is a stimulous to the nutrient matters in the plant in the direction of the increase, both of roots and of the multiplication of the branches of the stem above ground, which not only favors the power of the root, but also strengthens the leaves and stalks to such a degree, that the matters prepared by;he physiological action of these parts are increased and applied to the formation Mo' tubers, while at the same time the direct action of the sun's rays on the soil is prevented by the thick foliage, and thus the drying up of the soil and its injurious consequences are avoided. The checking of the transformation in the leaf is equivalent to the interruption of the natural change of the leaves into calyces, corollae, stamens, and pistils, which is effected at the expense of the nutrient matters collected in the plant; and these, when this modification of the leaves is arrested, are turned to account in the formation of tubers. " Led by these views, I made, in 1846, experiments on single potato plants, carefully marked by pinching off the-ends of the branches. They were so readily distinguished in their subsequent growth from the plants beside them, by more numerous branches, larger and darker foliage, that in truth no marking was necessary. "The produce from these plants of tubers was abundant, and the tubers were perfectly healthy; while the plants next them which had not been so treated, gave uniformly less produce, at the same time the tubers were rough on the surface,. and in many instances attacked with the prevailing disease. This experiment was incomplete, and did not give a positive result, but it was yet encouraging for me. 4"In the middle of April, 1847, an experiment was made on a low-lying field with the round white potatoes, generally cultivated here, a variety which had not suffered much from the disease which first appeared here 1845. The potatoes were planted in the usual way by an experienced farm servant. "After weeding them in the end of May, I renewed my experiment by pinching off the points of the branches of every second row, and repeated this in the end of June. The result surpassed all expectations. The stocks of the plants not treated * Any one would be bitterly disappointed, who on the principle, that "there cannot be too much of a good thing," should take off more than is here recommended, in order to use it as fodder. APPENDIX. 47 on my plan, were long, straggling, and sparingly furnished with leaves, the leaves themselves, small and pale gr'een. "In the next field, potatoes of the same variety were planted on the same day and left to nature. They appeared in the first six weeks healthy, even strong, but gradually acquired a poor aspect as the time of flowering and fruit approached, and finally, exhibited precisely the same appearance as the rows not treated by pinching off the extremities in the field in which my experiments were made. "The harvest began in the surrounding fields in the middle of August, and was very middling. The tubers were throughout smaller than usual, very scabby, and within these fields, to a small extent, attacked by the wet rot. "In the end of August, the difference between the rows treated by me and those not treated, became so striking that it astonished all the work people in the neighborhood, who were never tired of inquiring the cause. The stocks of the rows left to themselves were all now partly dried, partly dead. On the contrary, the rows treated as above were luxuriant and in full vigour, thle plants bushy, the foliage thick, the leaves large and green, so that most people suppposed they had been later planted. "4But the difference in the tubers was also very decided. The tubers of the plants in the rows treated on my plan were not, indeed larger, but vastly more numerous, and they were neither scabby nor affected with any disease whatever. A few had pushed (which was to be ascribed to a late rain,) and were apparently incompletely developed, while scab and wet rot attacked more and more the tubers of the other plants, which also fell off on the slightest handling. 1 "Although I am far from believing that I am able to explain the nature of the potato disease which has visited us of late years, yet i feel certain that I have discovered a means of strengthening the potato plant to such a degreea s to enable it to resist the influences which determine such diseases. "Should any one be deterred from continuing the cultivation of potatoes, on account of the manipulation here recommended, which may be performed by women and even by children, I would remind him that the same field planted with potatoes is capable of supplying food to twice as many persons as when employed to growing wheat."-From thle./r2nals of d.griculture in Prussia, edited by the Colleoe of Rural.Economy. DR. KLOTZSCH presented to the King of Prussia a memorial offering to give to the world' his method of preventing disease in potatoes, provided he were assured of a remuneration of 2,000 dollars,-(about t300,) if, after three years experience it should be found efficacious. The King handed the memorial to the Minister of the Interior, who requested,he College of Rural Economy to discuss the matter with Dr. Klotzsch.'The president of the college undertook the arrangement, and, after Dr. Klotzsch had explained to him privately his method,'reported most favorably of it to the College, which unanimously recommended that the very moderate remuneration asked for by Dr. Klotzsch should be secured to him on the following conditions, which were accepted by him. 1. That the College of Rural Economy should be the judges of the efficacy of the proposed method. 2. That their decision should be given, at latest, within three years, provided the potato disease against which the plants are to be protected, should appear during that period. The Minister of the Interior- approved of the recommendation, and authorized the College to conclude an agreement with Dr. Klotzsch. The agreement has been concluded, and now the method is published that it may be tried and tested as widely as possible by comparative experiments, similar to those made by Dr. Klotzsch himself. The cost of it is stated not to exceed Is. 6d. per acre in Germany. It is very desirable that this method should be tried in the British Islands, and as the season for trying it now approaches, I have here given Dr. Klotzch's account entire. WILLLIAM GREGORY. THE END. CHEMISTRY IN ITS APPLICATION TO AGRICULTURE AND PHYSIOLOGY, BY JUSTUS LIEBIG, M.D., PH.D. F.R.S., M.R.I.A., PR)FESSOR OF CHEMIISTRY IN THE UNIVERSITY OF GIESSEN; KNIGHT OF THE HESSIAN ORDER, AND OF TIE IMPERIAL ORDER OF SAINT ANN; MIEMBER OF THE ROYAL ACADEMY OF SCIENCES OF STOCKHOLII; CORRESPONDING MIEMBER OF THE ROYAL ACADFMIES OF SCIENCES OF BERLIN AND MUNICI; OF THE IMPERIAL ACADEMY OF ST. PETERSBURGH; OF TILE ROYAL INSTITUTION OF AMSTERDAIM, ETC. ETC. EDITED FROM THE MANUSCRIPT OF THE AUTHOR BY LYON PLAYFAIR, PH.D. FROM THE LAST LONDON EDITION, MUCH IMPROVED. t il a b c. p j i a: T. B. PETERSON, No. 98 CHESNUT STREET. TO THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF- SCIENCE. ONE of the most remarkable features of modern times is the combination of large numbers of individuals representing the whole intelligence of nations, for the express purpose of advancing science by their united efforts, of learning its pro. gress, and of communicating new discoveries. The formation of such associations is, in itself an evidence that they were needed. It is not every one who is called by his situation in life to assist in extending the bounds of science; but all mankind have a claim to the blessings and benefits which accrue from its earnest cultivation. The foundation of scientific institutions is an acknowledgment of these benefits, and this acknowledgment proceeding from whole nations may be considered as the triumph of mind over empiricism. Innumerable are the aids afforded to the means of life, to manufactures and to commerce, by the truths which assiduous and active inquirers have discovered and rendered capable of practical application. But it is not the mere practical utility of these truths which is of importance. Their influence upon mental culture is most beneficial; and the new views acquired by the knowledge of them enable the mind to recognise, in the phenomena of nature, proofs of an Infinite Wisdom, for the unfathomable profundity of which, language has no expression. At one of the meetings of the chemical section of the " British Association for the Advancement of Science,') the honourable task of preparing a Report upon the state of Organic Chemistry was imposed upon me. In the present work I present the Association with a part of this report. I have endeavoured to developer in a manner correspondent to the present state of science, the fundamental principles of Chemistry in general, and the laws of Organic Chemistry in particular, in their application to Agriculture and Physiology; to the causes of fermentation, decay, and putrefaction; to the vinous and acetous fermentations, and to nitrification. The conversion of woody fibre into wood and mineral coal, the nature of poisons, contagions, and miasms, and the causes of their action on the living organism, have been elucidated in their chemical relations. I shall be happy if I succeed in attracting the attention of men of science to subjects which so well merit to engage their talents and energies. Perfect Agriculture is the true foundation of all trade and industry-it is the foundation of the riches of states. But a rational system of Agriculture cannot be formed without the application of scientific principles; for such a system must be based on an exact acquaintance with the means of nutrition of vegetables, and with the influence of soils and action of manure upon them. This knowledge we must seek 3 iV PREFACE. from chemistry, which teaches the mode of investigating the compostion and of studying the characters of the different substances from which plants derive their nourishment. The chemical forces play a part in all the processes of the living animal organism; and a number of transformations and changes in the living body are exclusively dependent on their influence. The diseases incident to the period of growth of man, contagion and contagious matters, have their analogues in many chemical processes. The investigation of the chemical connection subsisting between those actions proceeding in the living body, and the transformations presented by chemical compounds, has also been a subject of my inquiries. A perfect exhaustion of this subject, so highly important to medicine, cannot be expected without the co-operation of physiologists. Hence I have merely brought forward the purely chemical part of the inquiry, and hope to attract attention to the subject. Since the time of the immortal author of the "Agricultural Chemistry," no chemist has occupied himself in studying the applications of chemical principles to the growth of vegetables, and to organic processes. I have endeavoured to follow the path marked out by Sir Humphry Davy, who based his conclusions only on that which was capable of inquiry and proof. This is the path of true philosophical inquiry, which promises to lead us to truth-the proper object of our research. In presenting this report to the British Association I feel myself bound to convey my sincere thanks to Dr. Lyon Plairfair, of St. Andrew's, for the active assistance which has been afforded me in its preparation by that intelligent young chemist, during his residence in Giessen. I cannot suppress the wish that he may succeed in being as useful, by his profound and well grounded knowledge of chemistry, as his talents promise. JUSTUS LIEBIG. GiPsen, September 1, 1840. EDITOR'S PREFACE. THE former edition of this work was prepared in the form of a report on the present state of Organic Chemistry. The state of a science such as this could not be exhibited by a systematic treatise on organic compounds, but by showing that the science was so far advanced as to be useful in its practical applications. The work was written by a Chemist, and addressed to Chemists. The author did not flatter himself that his opinions would be so eagerly embraced by agriculturists, as circumstances have shown to be the case. Hence his language and style were less adapted for them than for those who are conversant with the abstract details of chemical science. But the eager reception of the work by agriculturists has shown that they possess an ardent desire to profit by the aids offered to them by Chemistry. It, therefore, became necessary to adapt the work for those who have not had an opportunity of making that science a peculiar object of study. The Editor has endeavoured to effect this change. In doing so, it was necessary to retain-the original character of the work; hence those alterations only have been made which are calculated to render the work more generally useful. It must be remembered that the object of the author was not to write a " System of Agricultural Chemistry," but to furnisn a "Treatise on the Chemistry of Agriculture." It is to be hoped that those who are acquainted with the general doctrines of Chemistry will find no difficulty in comprehending any of the principles here developed. The author has enriched the present edition with many valuable additions; allusion may be particularly made to the practical illustration of his principles furnished in the Supplementary Chapter on Soils. The analyses of soils contained in that chapter will serve to point out the culpable negligence exhibited in the examination: of English soils. Even in the analyses of professional chemists, published in detail, and with every affectation of accuracy, the estimation of the most important ingredients is neglected. How rarely do we find phosphoric acid among the products of their analyses? potash and soda would appear to be absent from all soils in the British territories! Yet these are invariable constituents of fertile soils, and are conditions indispensable to their fertility. Primrose, NV'ovember 22, 1841. 5 CONTENTS. Object of the Work...... 9 PART FIRST. ON THE CHEMICAL PROCESSES IN THE NUTRITION OF VEGETABLES. CHAPTER PAGE I.-On the Constituent Elements of Plants..10 II.-On the Assimilation of Carbon... o 12 III.-On the Origin and Action of Humus.,. ~ 23 IV.-On the Assimilation of Hydrogen. 27 V.-On the Origin and Assimilation of Nitrogen. 30 VI.-On the Inorganic Constituents of Plants... 36 VII.-The Art of Culture........ 43 VIII.-On the Alternation (Rotation) of Crops. 54 IX.-On Manure........ 59 Supplementary Chapter.-On the Chemical Constituents of Soils 70 Appendix to Part I.. 84 PART SECOND. ON THE CHEMICAL PROCESSES OF FERMENTATION, DECAY, AND PUTREFACTION. CHAPTER PAGE I.-Chemical Transformations... 87 II. On the Causes which effect Fermentation, Decay, and Putrefaction....'.. 88 lII.-Fermentation and Putrefaction.... 90 IV.-On the Transformation of Bodies which do not contain Nitrogen as a constituent, and of those in which it is present 92 V. —Fermentation of Sugar. 95 VI.-Eremacausis, or Decay..... 98 VII.-Eremacausis of Bodies destitute of Nitrogen: Formation of Acetic Acid.100 VIII.-Eremacausis of Substances containing Nitrogen: Nitrification 102 IX.-On Vinous Fermentation: Wine' and Beer.. 103 X. —On the Decay of Woody Fibre. o. 110 XI.-On Vegetable Mould.. 112 XII.-On the Mouldering of Bodies: Paper, Brown Coal, and Mineral Coal... 112 XIII.-On Poisons, Contagions, and Miasms... 115 Appendix to Part II.... 129 Index....... 131 7 ORGANIC CHEMISTRY IN ITS APPLICATION TO VEGETABLE PHYSIOLOGY AND AGRICULTURE, THE object of Chemistry is to examine and the changes which they undergo in the into the composition of the numerous modifi- process of assimilation. cations of matter which occur in the organic A beautiful connection subsists between and inorganic kingdoms of nature, and to the organic and inorganic kingdoms of nainvestigate the laws by which the combina- ture. Inorganic matter affords food to tion and decomposition of their parts is plants, and they, on the other hand, yield effected. the means of subsistence to animals. The Although material substances assume a conditions necessary for animal and vegetvast variety of forms, yet chemists have not able nutrition are essentially different. An been able to detect more than fifty-five animal requires for its development, and for bodies which are simple, or contain only the sustenance of its vital functions, a cerone kind of matter, and from these all other tain class of substances which can only be substances are produced. They are con- generated by organic beings possessed of sidered simple only because it has not been life. Althougri many animals are entirely proved that they consist of two or more carnivorous, yet their primary nutriment parts. The greater number of the elements must be derived from plants; for the animals occur in the inorganic kingdom. Four only upon which they subsist receive their nourare found in organic matter. ishment from vegetable matter. But plants But it is evident that this limit to their find new nutritive material only in inorganic number must render it more difficult to as- substances. Hence one great end of vegetcertain the precise circumstances under able life is to generate matter adapted for which their union is effected, and the laws the nutrition of animals out of inorganic which regulate their combinations. Hence substances, which are not fitted for this purchemists have only lately turned their at- pose. Now the purport of this work is, to tention to the study of the nature of bodies elucidate the chemical processes engaged in generated by organized beings. A few the nutrition of vegetables. years have, however, sufficed to throw The first part of it will be devoted to the much light upon this interesting depart- examination of the matters which supply ment of science, and numerous facts have the nutriment of plants, and of the changes been discovered which cannot fail to be which these matters undergo in the living of importance in their practical applica- organism. The chemical compounds which tions. afford to plants their principal constituents, The peculiar object of organic chemistry viz., carbon and nitrogen, will here come is to discover the chemical conditions essen- under consideration, as well as the relations tial to the life and perfect development of in which the vital functions of vegetables animals and vegetables, and generally to in- stand to those of the animal economy and to vestigate all those processes of organic other phenomena of nature. nature which are due to the operation of The second part of the work will treat of chemical laws. Now, the continued exist- the chemical processes which effect the ence of all livin'g beings is dependent on the complete destruction of plants and animals reception by them of certain substances, after death, such as the peculiar modes of which are applied to the nutrition of their decomposition, usually described asfernmenframe. An inquiry, therefore, into the con- tation, putrefaction, and decay; and in this ditions on which the life and growth of part the changes which organic substances living beings depend, involves the study of undergo in their conversion into inorganic those substances which serve them as nutri- compounds, as well as the causes which ment, as well as the investigation of the determine these changes, will become matter sources whence these substances are derived, of inquiry. 2 9 PART I. OF THE CHEMICAL PROCESSES IN THE NUTRITION OF VEGETABLES. CHAPTER I. of plants, and during their life is subject to the control of the vital powers. But when OF THE CONSTITUENT ELEMENTS OF PLANTS. the mysterious principle of life has ceased to exercise its influence, this element reTHE ultimate constituents of plants are sumes its chemicalcharacter, and materially those which form organic matter in general, assists in promoting the decay of vegetable namely, Carbon, Hydrogen, Nitrogen, and matter, by escaping from the compounds of Oxygen. These elements are always pre- which it formed a constituent. sent in plants, and produce by their union Oxygen, the only remaining constituent the various proximate principles of which of organic matter, is a gaseous element, they consist. It is, therefore, necessary to which plays a most important part in the be acquainted with their individual charac- economy of nature. It is the agent emters, for it is only by a correct appreciation ployed in effecting the union and disunion of these that we are enabled to explain the of a vast number of compounds. It is supefunctions which they perform in the veget- rior to all other elements in the extensive able organization. range of its affinities. The phenomena of Carbon is an elementary substance, en- combustion and decay are examples of the dowed with a considerable range of affinity. exercise of its power. xVith oxygen it unites in two proportions, Oxygen is the most generally diffused forming the gaseous compounds lnown element on the surface of the earth; for, under the names of carbonic acid and car- besides constituting the principal part of the bonic oxide. The former of these is emit- atmosphere which surrounds it, it is a comted in immense quantities from many vol- -ponent.of almost all the earths and minerals canoes and mineral springs, and is a product found on its surface. In an isolated state it of the combustion and decay of organic is a gaseous body, possessed of neither taste matter. It is subject to be decomposed by nor smell. It is slightly soluble in water, various agencies, and its elements then ar- and hence is usually found dissolved in rain range themselves into new combinations. and snow, as well as in the -water of running Carbon is familiarly known as charcoal, but streams. in this state it is mixed with several earthy Such are the principal characters of the bodies; in a state of absolute purity it con- elements which constitute organic matter; stitutes the diamond. but it remains for us to consider in what IHydrogen is a very important constituent form they are united in plants. of vegetable matter. It possesses a. special The substances which constitute the prinaffinity for oxygen, with which it unites and cipal mass of every vegetable are cornmforms water. The whole of the phenomena pounds of carbon with- oxygen and hydroof decay depend upon the exercise of this gen,'in the proper relative proportions for affinity, and many of the processes engaged forming water. Woody fibre, starch, sugar, in the nutrition of plants originate in the and gum, for example, are such compounds attempt to gratify it. Hydrogen, when in of carbon With the elements of water. In the state of a gas, is very combustible, and another class of substances containing carthe lightest body known; but it is never bon as an element, oxygen and hydrogen are found in nature in an isolated condition. again present; but the proportion of oxygen Water is the most common combination in is greater than would be required for producwhich it is presented; and it may be re- ing water by union with the hydrogen. The moved by various processes from the oxygen, numerous organic acids met with in plants with which it is united in this body. belong, with few exceptions, to this class..Nitrogen is quite opposed in its chemical A third class of vegetable compounds characters to the two bodies now described. contains carbon and hydrogen, but no oxyIts principal characteristic is an indifference gen, or less of that element than would be to all other substances, and an apparent re- required to convert all the hydrogen into luctance to enter into combination with water. These may be regarded as comthem. When forced by peculiar circum- pounds of carbon' with the elements of stances to do so, it seems to remain in the water, and an excess of hydrogen. Such combination by a vis inertice; and very are the volatile and fixed oils, wax, and the slight forces effect the disunion of these resins. Many of them have acid characters. feeble compounds. The juices of all vegetables contain orYet nitrogen is an invariable constituent ganic acids, generally combined with the 10 THE ATMOSPHERE.-SOILS. 11 inorganec bases, or metallic oxides; for these mer of these falls upon the earth as rain, metalic oxides exist in every plant, and may and brings with it any soluble matter which be detected in its ashes after incineration. it meets in its passage.through the air. Nlitrogen is an element of vegetable albu- Carbonic acid gas is discharged in immen and gluten; it is a constituent of the mense quantities from the active volcanoes acid, and of what are termed the " indiffer- of America, and from many of the mineral ent substances?' of plants, as well as of springs which abound in various parts of those peculiar vegetable compounds which Europe; it is also generated during the possess all the properties of metallic oxides, combustion and decay of organic matter. and are known as "organic bases." It is not, therefore, surprising that it should Estimated by;ts proportional weight, ni- have been detected in every part of the trogen forms onlva very small part of plants; atmosphere in which its presence has been but it is never entirely absent from any part looked for. Saussure found it even in the of them. Even when it does not absolutely air on the summit of Mont Blanc, which is enter into the composition of a particular covered with perpetual snow, and where it part or organ, it is always to be found in the could not be produced by the immediate fluids which pervade it. agency of vegetable matter. Carbonic acid It follows from the facts thus far detailed, gas performs a most important part in the that the development of a plant requires process of vegetable nutrition, the considerathe presence, first, of substances containing tion of which belongs to another part of the carbon and nitrogen, and capable of yield- work. ing these elements to the growing organism;- Carbonic acid, water, and ammonia (a secondly, of water and its elements; and compound of hydrogen and nitrogen) are' lastly, of a soil to furnish the inorganic the final products of the decay of animal and matters which are likewise essential to ve- vegetable matter. In an isolated condition, getable life. they usually exist in the gaseous form. Hence, on their formation, they must escape OF THE COMPOSITION OF THE ATMOSPHERE. into the atmosphere. But ammonia has not hitherto been enumerated among the conIn the normal state of growth plants can stituents of the air, although, according to only derive their nourishment from the our view, it can never be absent. The reaatmosphere and the soil. Hence it is of son of this is, that it exists in extremely miimportance to be acquainted with the com- nute quantity in the amount of air usually position of these, in order that we may be subjected to experiment in chemical analvenabled to judge from which of their con- sis; it has consequently escaped detection.. stituents the nourishment is afforded. But rain which falls through a large extent The composition of the atmosphere has of air,. carries down in solution all that rebeen examined by many chemists with great mains in suspension in it. Now ammonia care, and the result of their researches have always exists in rainwater, and from this shown, that its principal constituents are fact we must conclude that it is invariably always present in the same proportion. present in the atmosphere. Nor can we be These are the two gases, oxygen and nitro- surprised at its presence when we consider gen, the general properties of which have that many volcanoes now in activity emit been already described. One hundred parts, large quantities of it. This subject will, by weight, of atmospheric air contain 23'1 however, be discussed more fully in anothei parts of oxygen, and 76-9 parts of nitrogen; part of the work. or 100 volumes of air contain nearly 21 Such are the principal constituents of the volumes of oxygen gas. From the exten- atmosphere from which plants derive their sive range of affinity which this gas pos- nourishment; for although other matters are sesses, it is obvious, that were, it alone to supposed to exist in it in minute quantity, constitute our atmosphere, and left un- yet they do not exercise any influence on checked tu exert its powerful effects, all na- vegetation, nor has even their presence been ture would be one scene of universal destruc- satisfactorily demonstrated. tion. It is on this account that nitrogen is present in the air in so large proportion. It is OF SOILS. peculiarly adapted for this purpose, as it does not possess any disposition to unite with oxy- A soil may be considered a magazine of gen, and exerts no action upon the processes inorganic matters, which are prepared by proceeding on the earth. These two gases the plant to suit the purposes destined for are intimately mixed, by virtue of a pro- them in its nutrition.' The composition and perty which all gasses possess in common, uses of such substances cannot, however, of diffusing themselves equally through be studied with advantage, until we have every part of another gas, with which they considered the manner in which the organic are placed in. contact. matter is obtained by plants. Although oxygen and nitrogen form the Some virgin soils, such as those of Ameprincipal constituents of the atmosphere, rica, contain vegetable matter in large proyet they are not the only substances found portion; and as these have been -found emiin it. Watery vapour and carbonic acid gas nentlv adapted for the cultivation of most materially modify its properties. The for- plants, the organic matter contained in themn 12 AGRICULTURAL CHEMISTRY. has naturally been recognised as the cause and the proportion of carbon in the respective of their fertility. To this matter, the term cases has been found to agree with the esti"vegetable mould" or humus has been ap- mates of the different chemists above menplied. Indeed, this peculiar substance ap- ti'oned; so that there is no reason to ascribe pears to play such an. important part in the the difference in this respect between the phenomena of vegetation, that vegetable varieties of humus to the mere difference in physiologists have been induced to ascribe the methods of analysis or degrees of exthe fertility of every soil to its presence. It pertness of the operators. Malaguti states, is believed by many to be the principal'nu- moreover, that humic acid contains an equal triment of plants, land is supposed to be ex- number of equivalents of oxygen and hytracted by them from the soil in which they drogen, that is to say, that these elements grow. It is itself the product of the decay exist in it in the proportions for forming of vegetable matter, and must, therefore, con- water; while, according to Sprengel, the'tain many of the constituents which are oxygen is in excess, and Peligot even estifound in plants during life. Its action will, mates the quantity of oxygen at 14 equivatherefore, beexaminedinconsideringwhence lents, and the hydrogen at only 6 equivathese constituents are derived. lents, making the deficiency of hydrogen as great as 8 equivalents. And although Mulder~ has very recently explained many of these conflicting results, by showing that CHAPTER II. there are several kinds of humus and humic acids, essentially distinct in their characters, OF THE ASSIMILATION OF CARBON. and fixed in their composition, yet he has afforded no proof that the definite compounds COMPOSITION OF HUMUS. obtained by him really exist,' as such, in the soil. On the contrary, they appear to have THE humus, to which allusion has been been formed by the action of the potash and made, is described by chemists as a brown amronia, which he employed in their presubstance easily soluble in alkalies, but only paration. slightly so in water, and produced during It is quite evident, therefore, that chemists the decomposition of vegetable'matters by have been in the habit of designating all the action of acids or alkalies. It has, how- producis of the decomposition of organic ever, received various names according to bodies which had a brown or brownish the different external characters and chenli- Iblack colour, by the names of humic acid or cal properties which it presents. Thus, humin, according as they were soluble or ulmin, humic acid, coal of humus, and humlit, insoluble in alkalies; although in their are names applied to modifications of humus. conmposition and mode of origin, the subThey are obtained by treating peat, woody stances thus confounded might be in no fibre, soot, or brown coal with alkalies; by'wav allied. decomposing sugar, starch, or sugar of milk Not the slightest ground exists for the beby means of acids; or by exposing alkaline lief that one or other of these artifitial prosolutions of tannic and gallic acids to the ducts of the decomposition of vegetable action of the air. matters exists in nature in the form and enThe modifications of humus which are dowed with the properties of the vegetable soluble in alkalies, are called humic acid; constituents of mould; there is not the while those which are insoluble have re- shadow of a proof that one of them exerts ceived the designations of humin and coal of iany influence on the growth of plants either humas. in the way of nourishment or otherwise. The names given to these substances Vegetable physiologists have, without any might cause it to be supposed that their apparent reason, imputed the known procomposition is identical. But a more erro- perties of the humus and hlumic acids of neous notion could not be entertainad; since chemists to that constituent of mould which even sugar, acetic acid, and resin do not has received the same name, and in this differ more widely in the proportions of their way have been led to their theoretical noconstituent elements, than do the various tions respecting the functions of the latter modifications of humus. substance in vegetation. Humic acid formed by the action of hy- The opinion that the substance called drate of potash upon sawdust contains, ac- humus is extracted from the soil by the roots cording to the accurate analysis of Peligot. I of plants, and that the carbon enteringinto 72 per cent. of carbon, while the hurnic acid its composition serves in some form or obtained from turf and brown coal contains, other to nourish their tissues, is considered according to Sprengel, only 58 per cent.; I by many as so firmly established that any that prod ced by the action of dilute sul- new argument in its favour has been deemed phuric acid upon sugar, 57 per cent. accord- unnecessary; the obvious difference in then: ing to Malaguti; and that, lastly, which is ]growth of plants according to the known obtained from sugaror from starch, by means a! bundance or scarcity of hunus in the soil, of muriatic acid, according to the analysisi of Stein, 64 per cent. All these analyses * Bulletin des Scienc. Phys. et Natur. de Neerl. have been repeated with care and accuracy, j 1840, p. 1]102. ABSORPTION OF HUMIS. 13 seemed to afford incontestable proof of its only slight traces of soluble materials; and correctness. I have myself verified this observation on Yet, this position, when submitted to a the decayed wood of beech and fir. strict examination, is found to be untenable, These facts, which show that humic, in and it becomes evident from most conclusive its unaltered condition, cannot serve for the proofs that humus in the form in which it nourishment of plants, have not escaped the exists in the soil, does not yield the smallest notice of physiologists; and hence they have nourishment to plants. assumed that the lime or the different alkaThe adherence to the above incorrect lies found in the ashes of vegetables render opinion has hitherto rendered it impossible soluble the humic acid and fit it for the profor the true theory of the nutritive process cess of assimulation. in vegetables to become known, and has thus Alkalies and alkaline earths do exist in deprived us of our best guide to a rational the different kinds of soil in sufficient quanpractice in agriculture. Any great improve- tity to form such soluble compounds with ment in that most important of all arts is in- the humic acid. conceivable without a deeper and more per- Now, let us suppose that humic acid is fect acquaintance with the substances which absorbed by plants in the form of that salt nourish plants, and with the sources whence which contains the largest proportion of they are derived; andno other cause can humic acid, namely, in the form of humate be discovered to account for the fluctuating of lime, and then from the known quantity and uncertain state of our knowledge on of the alkaline bases contained in the ashes this subject up to the present time, than of plants, let us calculate the amount io that modern physiology has not kept pace humic acid which might be assimulated in with the rapid, progress of chemistry. this manner. Let us admit, likewise, that In the following inquiry we shall suppose potash, soda, and the oxides of iron and the humus of vegetable physiologists to be manganese have the same capacity of satureally endowed with the properties recog- ration as lime with respect to humic acid, nised by chemists in the brownish black de- and then we may take as the basis of our posits which they obtain by precipitating an calculation the analysis of M. Berthier, who alkaline decoction of mould or peat by found that 1000 lbs. of dry fir wood yielded means of acids, and which they name humic 4 lbs. of ashes, and that in every 100 lbs. of acid. these ashes, after the chloride of potassium Humic acid, when first precipitated, is a and sulphate of potash were extracted, 53 flocculent substance, is soluble in 2500 lbs. consisted of the basic metallic oxides, times its weight of water, and combines potash, soda, lime, magnesia, iron, and with alkalies, lime and magnesia, forming manganese. compounds of the same degree of solubility. One Hessian acre' of woodland yields (Sprengel.) annually, according -to Dr. Hever, on an Vegetable physiologists agree in the sup- average, 2920 lbs. of dry fir wood, which position that by the aid of water humus is contain 6.17 lbs. of metallic oxides. rendered capable of being absorbed by the Now, according to the estimates of Malaroots of plants. But according to the ob- guti and Sprengel, 1 lb. of lime combines servation of chemists, humic acid is soluble chemically with 12 lbs. of' humic acid; 6.17 only when newly precipitated, and becomes lbs. of the metallic oxides would accordingly completely insoluble when dried in the air, introduce into the trees 67 lbs. of humic or when exposed in the moist state to the acid, which, admitting humic acid to confreezing temperature. (Sprengel.) tain 58 per cent. of carbon, would corresBoth the cold of winter and the heat of pond to 100 lbs. of dry wood. But we have summer, therefore, are destructive ofthe solu- seen that 2920 lbs. of fir wood are really bility of humic acid, and at the same time of produced. its capability of being assimilated by plants. Again, if the quantity of humic acid So that, if it is absorbed by plants, it must which might be introduced into wheat in be in some altered form. the form of humates is calculated from the The correctness of these observations is known proportion of metallic oxides existeasily demonstrated by treating a portion of ing in wheat straw, (the sulphates and good mould with cold water. The fluid re- chlorides also contained in the ashes of the mains colourless, and is found to have dis- straw not being included, it will be found solved less than 100,000 part of its weight that the wheat growing on 1 Hessian acre of organic matters, and to contain merely would receive in that way 63 lbs. of humic the salts which are present in rainwater. acid, corresponding to 93.6 lbs. of woody Decayed oak wood, likewise, of which fibre. But the extent of land just mentioned hurnic acid is the principal constituent, was produces, independently of the roots and found by Berzelius to.yield to cold water grain, 1961 lbs. of straw, the composition This remrkappie moe o Grmn tanof which is the same as that of woody fibre. * This remark applies more to German than It has been taken for granted in these calto English botanists and physiologists. In England, the idea that humus, as such, affords nourishment to plants is by no means general; but on * One Hessian acre is equal to 40,000 square the Continent, the views of Berzelius on this sub- feet, Hessian, or 26,910 square feet, English moaject have been almost universally adopted.-ED. sure B 14 AGRICULTURAL CHEMISTRY. eulations that the basic metallic oxides tain 38 parts of carbon; therefore, 2920 lbs. which have served to introduce humic acid contain 1109 lbs. of carbon. into the plants do not return to the soil, One hundred parts of hay,e dried in air, since it is certain that they remain fixed in contain 44.31 parts carbon. Accordingly, the parts newly formed during the process 2755 lbs. of hay contain 1111 lbs. of carbon. of growth. Beet roots contain from 89 to 89.5 parts Let us now calculate the quantity of water, and from 10.5 to 11 parts solid mathumic acid which plants can receive under ter, which consists of from 8 to 9 per cent. the most favourable circumstances, viz. sugar, and from 2 to 21 per cent. cellular the agency of rainwater. tissue. Sugar contains 42.4 per cent; celThe quantity of rain which falls at Er- lular tissue, 47 per cent. of carbon. furt, one of the most fertile districts of Ger- 22,000 lbs. of beet root, therefore, if they many, during the months of April; May, contain 9 per cent. of sugar, and 2 per cent. June, and July, is stated by Schubler to be of cellular tissue, would yield 1032 lbs. of 19.3 lbs. over every square foot of surface; carbon, of which 833 lbs. would be due to 1 Hessian acre, or 26,910 square feet, con- the sugar, and 198 lbs. to the cellular tissue; sequently receive 771,000 lbs. of rainwater. the carbon of the leaves and small roots not If, now, we suppose that the whole quan- being included in the calculation. tity of this rain is taken up by the roots of a One hundred parts of straw,t dried in air summer plant, which ripens four months contain 38 per cent. of carbon; therefore, after it is planted, so that not a pound of 1961 lbs. of straw contain 745 lbs. of carbon. this water evaporates except from the leaves One hundred parts of corn contain 43 parts of the plant; and if we farther assume that of carbon; 882 lbs. must, therefore, contain the water thus absorbed is saturated with 379 lbs.-in all, 1124 lbs. of carbon. humate of lime (the most soluble of the hu- 26,910 square feet of wood and meadow mates, and that which contains the largest land produce, consepuently, 1109 lbs. of proportion of humic acid;) then the plants carbon; while the same extent of arable land thus, nourished would not receive more than yields in beet root, without leaves, 1032 lbs., 330 lbs. of humic acid, since one part of or in corn, 1124 lbs. humate of lime requires 2500 parts of water It must be concluded from these inconfor solution. testable facts, that equal surfaces of cultiBut the extent of land which we have vated land of an average fertility produce mentioned produces 2843 lbs. of corn (in equal quantities of carbon; yet, how unlike grain and straw, the roots not included,) or have been the different conditions of the 22,000 lbs. of beet root (without the leaves growth of the plants from which this has and small radicle fibres.) It is quite evident been deduced! that the 330 lbs. of humic acid, supposed to Let us now inquire whence the grass in be absorbed, cannot account for the quantity a meadow, or the wood in a forest, receives of carbon contained in the,roots and leaves its carbon, since there no manure-no caralone, even if the supposition were correct, bon-has been given to it as nourishment? that the whole of the rainwater was ab- and how it happens, that the soil, thus exsorbed by the plants. But since it is known hausted, instead of becoming, poorer, bethat only a small portion of the rainwater comes every year richer in this element? which falls upon the surface of the earth A certain quantity of carbon is taken evaporates through plants, the quantity of every year from the forest or meadow, in carbon which can be conveyed into them in the fobrm of wood or hay, and, in spite of any conceivable manner by means of humic this, the quantity of carbon in the soil augacid must be extremely trifling, in compa- meats; it becomes richer in- humus. rison with that actually produced in vege- It is said that in fields arid orchards all tation. the carbon which may have been taken Other considerations of a higher nature away as herbs, as straw, as seeds, or as confute the common view respecting the. fruit, is replaced by means of manure; and nutritive office of humic acid, in a manner yet this soil produces no more carbon than so clear and conclusive that it is difficult to that of the forest or meadow, where it is conceive how it could have been so gene- never replaced. It cannot be conceived that rally adopted. the laws for the nutrition of plants are Fertile land produces carbon in the form changed by culture,-that the sources of of wood, hay, grain, and other kinds of growth, the masses of which differ in a remarkable degree. 100 parts of hay. dried at 100~ C. (212o F.) and a2920 lbs of firs, pines, beeches, &c. grow burned with oxide of copper in a stream'of oxygen 2920 lbs. of firs, pines, beeches, &c. grow gas, yielded 51.93 water, 165.8 carbonic acid, and as wood upon one Hessian acre of forest 6.82 of ashes. This gives 45 87 carbon, 5.76 hyland with an average soil. The same super- drogen, 31.55 oxygen, and 6.82 ashes. Hay, dried flees yields 2755 lbs. of hay. in the air, loses 11.2 p. c. water at 100~ C. (212 A similar surface of corn land gives from F.)-(Dr. TIill.) 19,000 to 22,000 lbs. of beet root, or 881 lbs. t Straw analyzed in the same manner, and dried of rye, and 1961 lbs. of straw, 160 sheaves at 100~ C., gave 46.37 p. c. of carbon, 5.68 p. c. of hydrogen, 43.93 p. c. of oxygen, and 4.02 p. c. of of 15.4 lbs. each, —in all, 2843 lbs. ashes. Straw dried in the air at 100' C. lost 18 p. One hundred parts of dry fir wood con- c. of water. —Dr. IMill. OXYGEN AND CARBON. 15 carbon for fruit or grain, and for grass or for 1800 years in Pompeii appears quite trees, are different. incomprehensible, unless some source exists It is not denied that manure exercises an whence the oxygen abstracted is replaced. influence upon the development of plants; How does it happen, then, that the proporbut it may be affirmed with positive cer- tion of oxygen in the atmosphere is thus tainty, that it neither serves for the produc- invariable? tion of the carbon, nor has any influence The answer to this question depends upon upon it, because we find that the quantity another; namely, what becomes of the carof carbon produced by manured lands is bonic acid, which is produced during the not greater than that yielded by lands which respiration of animals, and by the process are not manured. The discussion as to the of combustion? A cubic foot of oxygen manner in which manure acts has nothing gas, by uniting witn carbon so as to form to do with the present question, which is, carbonic acid, does not change its volume. the origin of the carbon. The carbon must The billions of cubic feet of oxygen exbe derived from other sources; and as the tracted from the atmosphere, produce the soil does not yield it, it can only, be ex- same number of billions of cubic feet of tracted from the atmosphere. carbonic acid, which immediately supply its In attempting to explain the origin of place. carbon in plants, it has never been con- The most exact and most recent experisidered that the- question is intimately con- ments of De Saussure, made in every seanected with that of the origin of humus. It son for a space of three years, have shown, is universally admitted that humas arises that the air contains on an average 0'000415 from the decay of plants. No primitive of its own volume of carbonic acid gas; so humus, therefore, can have existed-for that, allowing for the inaccuracies of the plants must have preceded the humus. experiments, which must diminish the Now, whence did the first vegetables de- quantity obtained, the proportion of carbonic rivettheir carbon? and in what form is the acid in the atmosphere may be regarded as carbon contained in the atmosphere? nearly equal to 1-1000 part of its weight. These two questions involve the conside- The quantity varies according to the sea ration of two most remarkable natural phe- sons; but the yearly average remains con:nomena, which by their reciprocal and un- tinually the same. interrupted influence maintain the life of the We have no reason to believe that this individual animals and vegetables, and the proportion was less in past ages; and nevercontinued existence of both kingdoms of or- theless, the immense masses of carbonic ganic nature. acid which annually flow into the atmosOne of these questions is connected with phere from so many causes, ought perceptithe invariable condition of the air with re- bly to increase its quantity from year to spect to oxygen. One hundred volumes of year. But we find that all earlier observers air have been found, at every period and in describe its volume as from one-half to ten every climate, to contain 21 volumes of times greater than that which it has at the oxygen, with such small deviations that they present time; so that we can hence at most must be ascribed to errors of observation. conclude that it has diminished. Although the absolute quantity of oxygen It is quite evident that the quantities of contained in the atmosphere'appears very carbonic acid and oxygen in the atmosphere, great when represented by numbers, yet it which remain unchanged by lapse of time, is not inexhaustible. One man consumes must stand in some fixed relation to one by respiration 25 cubic feet of' oxygen in another; a cause must exist which prevents 22 hours; 10 cwt. of charcoal consume the increase of carbonic acid by removing 32,066 cubic feet of oxygen during its cornm- that which is constantly forming; and there bustion; and a small town, like Giessen, (with about 7000 inhabitants) extracts yearly Volume of atmosphere = 9,307,500 cubic miles. from the air, by the wood employed as fuel, =cube of 210,4 miles. more than 551 millions of cubic feet of this Volume of oxygen = 1,954,578 cubic miles. - cube of 125_miles. Vol. of carbonic acid =3,862'7 cubic miles. When we consider facts such as these, = cube of 15'7 miles. our former statement, that the quantity of The maximum of the carbonic acid contained oxygen in the atmosphere does not diminish in the atmosphere has not here been adopted, but in the course of ages —that the air at the the mean, which is equal to 0000415. present day, for example, does not contain A man daily consumes 45,000 cubic inches (Parisian.) A man yearly consumes 9505'2 cubic less oxygen than that found in jars buried feet. 100 million yearly consume 9,505,200,000,000 cubic feet. Hence a thousand million men yearly consume * If the atmosphere possessed, in its whole ex- 0'79745 cubic miles of oxygen. But the air is tent, the same density as it does on the surface rendered incapable of supporting the process of of the sea, it would have a height of 24,555 respiration, when the quantity of its oxygen is Parisian feet; but it contains the vapour of water, decreased 12 per cent.; so that a thousand million so that we may assume its height to be one geo- men would make the air unfit for respiration in a graphical mile =22,843 Parisian feet. Now the million years. The consumption of oxygen by radius of the earth is equal to 860 geographical animals, and by the process of combustion, is not miles; hence the introduced into the calculation. 16 AGRICULT JRAL CHEMISTRY. must be some means of replacing the oxy- the operation recommences iff a new portion gen, which is removed from the air by of it is added. the processes of combustion and putre- Plants do not emit gas when placed in faction, as well as by the respiration of water which either is free from carbonic anmials. acid, or contains an alkali that protects it Both these causes are united in the pro- from assimilation. cess of vegetable life. These observations were first made by The facts which we have stated in the Priestly and Sennebier. The excellent expreceding pages prove that the carbon of periments of De Saussure have farther plants must be derived exclusively from the shown, that plants increase in weight duratmosphere. tNow, carbon exists in the ing the decomposition of carbonic acid and atmosphere only in the form of carbonic separation of oxygen.' This increase in acid, and therefore, in a state of combination weight is greater than can be accounted for with oxygen. by the quantity of carbon assimilated; a fact It has been already mentioned likewise, which confirms the view, that the elements that carbon and the elements of water form of water are assimilated at the same time. the principal constituents of vegetables; the The life of plants is closely connected quantity of the substances which do not with that of animals, in a most simple manpossess this composition being in a very ner, and for a wise and sublime purpose. small proportion. Now, the relative quail- The presence of a rich and luxuriant vegetity of oxygen in the whole mass is less than tation may be conceived without the conin carbonic acid; for the latter contains two currence of animal life, but the existence of equivalents' of oxygen, while one only is animals is undoubtedly dependent upon the required to unite with hydrogen in the pro- life and development of plants. portion to form water. The vegetable pro- Plants not only afford the means of nutriducts which contain oxygen in larger pro- tion for the growth and continuance of aniportion than this, are, comparatively, few in mal organization, but they likewise furnish number; indeed, in many the hydrogen is in that which is essential for the support of the great excess. It is obvious, that when the important vital process of respiration; for, hydrogen of water is assimilated by a plant, besides separating all noxious matters from the oxygen in conlbination with it must be the atmosphere, they are an inexhaustible liberated, and will afford a quantity of this source of pure oxygen, which supplies the element sufficient for the wants of the plant. loss which the air is constantly sustaining. If this be the case, the oxygen contained in Animals on the other hand expire carbon, the carbonic acid is quite unnecessary in the which plants inspire; and thus the compoprocess of vegetable nutrition, and it will sition of the medium in which both exist, consequently escape into the atmosphere in namely, the atmosphere, is maintained cona gaseous form. It is, therefore, certain, that stantly unchanged. plants must possess the power of decom- "i It may be asked —is the quantity of carposing carbonic acid, since they appropriate bonic acid in the atmosphere, which scarcely its carbon for their own use. The forma- amounts to 1-10th per cent., sufficient for tion of their principal component substances -the wants of the whole vegetation on the must necessarily be attended with the sepa- surface of the earth,-is it possible that the ration of the carbon of the carbonic acid carbon of plants has its origin from the air from the oxygen, which must be returned to alone? This question is very easily anthe atmosphere, while the carbon enters swered. It is known, that a column of air into combination with water or its elements. of 2441 lbs. weight rests upon every square The atmosphere must thus receive a volume Hessian foot (=0.567 square foot English) of oxygen for every volume of carbonic of the surface of the earth; the diameter of qcid which has been decomposed. the earth and its superficies are likewise This remarkable property of plants has known, so that the weight of the atmosphere been demonstrated in the most certain man- can be calculated with the greatest exactness. ner, and it is in the power of every person The thousandth part of this is caroonic acid, to convince himself of its existence. ite which contains upwards of 27 per cent. carleaves and other green parts of a plant ab- bon. By this calculation it can be shown, sorb carbonic acid, and emit an equal that the'atmosphere contains 3306 billion volume of oxygen. They possess this pro- lbs. of carbon; a quantity which amounts to perty quite independently of the plant; for if, more than the weight of all the plants, and after being separated from the stem, they are of all the strata of mineral and brown coal, placed in water containing carbonic acid, which exist upon the earth. This carbon and exposed in that condition to the sun's is, therefore, more than adequate to all the light, the carbonic acid is, after a time, purposes for which it is required. The found to have disappeared entirely from the quantity of carbon contained in seawater is water. If the experiment is conducted un- proportionally still greater. der a glass receiver filled with water, the If, for the sake of argument, we suppose oxygen emitted from the plant may be col- the superficies of the leaves and other green.1ected and examined. When no more oxy- parts of plants, by which the absorption of gen gas is evolved, it is a sign that all the carbonic acid is effected, to be double that of dissolved carbonic acid is decomposed; but the soil upon which they grow, a supposi ASSIMILATION OF CARBON. 17 tion which is much under the truth in the proved, that the upper strata of the air conca-se of woods, meadows, and corn fields; tain more carbonic acid than the lower, and if we farther suppose that carbonic acid which are in contact with plants; and that equal to 0.00067 of the volume of the air, the quantity is greater by night than by day, or 1-1000th of its weight is abstracted from when it undergoes decomposition. it during every second of time, for eight Plants thus improve the air by the remohours daily, by a field of 53,814 square feet val of carbonic acid, and by the renewal of (=-2 Hessian acres;) then those leaves oxygen, which is immediately applied to would, receive. 1102 lbs. of carbon in two the use of man and animals. The horizonhundred days.* tat currents of the atmosphere bring with But it is inconceivable, that the functions them as much as they carry away, and the of the organs of a plant can cease for any interchange of air between the upper and one moment during its life. The roots and lower strata, which their difference of temother parts of it, which possess the same pterature causes, is extremely trifling when power, absorb constantly water and carbonic compared with the horizontal movements acid. This power is independent of solar of. the winds.. Thus vegetable' culture light. During the day, when the plants are heightens the healthy state of a country, in the shade, and during the night, carbonic and a previously healthy country would be acid is accumulated in all parts of their rendered quite uninhabitable by'the cessastructure; and the assimilation of the carbon tion of all cultivation. and -the, exhalation of oxygen commence The various layers of wood and mineral from the instant that the rays of the sun coal,'as well as peat, form the remains of a strike them. As soon as a young plant'primeval vegetation The. carbon which breaks through the surface of th'e ground, they contain must have been originally in it begins to acquire colour from the top the atmosphere as carbonic acid in which lownwards; and the true formation of form it was assimilated by the plants which woody tissue commences at the same time. constitute these formations. It follows from The proper, constant, and inexhaustible this, that the atmosphere must be richer in sources of oxygen gas are the tropics and oxygen at the present time than in former warm climates, where a sky, seldom cloud- periods of the earth's history. The increase ed, permits the glowing rays of the sun to must be exactly proportional to the quantity shine upon an immeasurably luxuriant ve- of carbon and hydrogen contained in these getation. The temperate and cold zones, carboniferous deposits. Thus, during the where artificial warmth must replace defi- formation of 353 cubic feet of Newcastle cient heat of the sun, produce, on the con- splint coal, the atmosphere must have retrary, carbonic acid in superabundance, ceived 643 cubic feet of oxygen produced which is expended in the nrutrition of the from the carbonic acid assimilated, and also tropical plants. The same stream of air, 158 cubic feet of the same gas resulting which moves by the revolution of the earth from the decomposition of water.. In forfrom the equator to the poles, brings to us mer ages, therefore, the atmosphere must in its passage from the equator, the oxygen have contained less oxygen, but a much generated there, and carries away the car- larger -proportion of carbonic acid, than it tonic acid formed during our winter.'does at the present time, a circumstance The experiments of De Saussure have which accounts for the richnessand luxuri_______________ ance of the earlier vegetation. * The quantity of carbonic acid which can be ex- But a certain period must have arrived in tracted from the air in a given time, is shown by which the quantity of carbonic acid conthe following calculation. During the whitewash- tained in the air experienced neither increase ing. of a small chamber, the superficies of the nor diminution in any appreciable quantitywalls and roof of which we will suppose to be 105 For if it received an additional quantity to square metres, and which receives six coats of lime in four days, carbonic acid is abstracted from its usual'proportion, an increased vegetation the air, and the lime is consequently converted, would be the natural consequence, and the on the surface, into a carbonate. It has been ac- excess would thus be speedily removed. curately determined that one square decimetre re- And, on the other hand, if the gas was less ceives in this way, a coating of carbonate of lime than the normal quantity, the progress which weighs 0.732 grammes. Upon, the 105 the square metres already mentioned there must ac- vegettion would be retarded, and the cordingly be formed 7686 grammes of'carbonate proportion would soon attain its proper of lime, which contain 4325.6 grammes of carbo- standard. J nic acid. T'he weight of one cubic decimetre of. The most important function in the life carbonic acid being calculated at two gramines. of plants or, in other words, in their as(more accurately 1.97978,) the above mentioned on of ca surface must absorb in four days 2.163 cubic me- the separa tres of carbonic acid. 2500 square metres (one might almost say the generation, of oxyge. Hessian acre) would absorb, under a similar treat- No matter can be considered as nutritious',. ment, 51.- cubic metres=1818 cubic feet of car- or as necessary to the growth of plants, b(hnic acid in four days. In 200 days it would ab- which possesses a composition either simiscCrb 2575 cubic metres= 904,401 cubic feet, which!ar to or identical with theirs, and the asccntain 11,353 lbs. of carbonic acid, of which 3304 similation of which, therefore, could take lbs. are carbon, a quantity three times as great as that which is assimilated by the leaves and roots place without exercising this function. The growing upon the same space. reverse is the case in the nutrition of ani3. as,2 18 AGRICULTURAL CHEMISTRY. mals. Hence such substances as sugar, were in a great degree the cause of this unstarch, and gum, which are themselves pro- certainty of opinion regarding the influence ducts of plants, cannot be adopted for as- of.plants in purifying the air. His obsersimilation. And this is rendered certain by vation that green' plants emit carbonic acid the experiments of vegetable physiologists, in the dark, led De Saussure and Grishcow who have shown that aqueous solutions of to new investigations, by which they ascerthese bodies are imbibed by the roots of tained that under such conditions plants lio plants, and carried to all parts of their struc- really absorb oxygen and emit carbonic acid; ture, but are not assimilated, they cannot, but that the whole volume of air ndergoes therefore, be employed -in their nutrition. diminutio.n at the same time. /From the We could scarcely conceive a form more latter fact it follows, that'the quantity of convenient for assimilation than that of oxygen gas' absorbed is. greater than the gum, starch, and sugar, for they ah contain volume of carbonic acid separated:; for, if the elements of woody fibre, and nearly in thiswere not the case, no diminution could the same proportions. occur. These facts cannot be doubted, but In the second part of the work we shall the views based on them have been so false, adduce satisfactory proofs that. decayed that nothing, except the total want of obserwoody fibre (humus) contains carbon and vation and the utmost ignorance of the the elements of water, without, an excess of chemical relations of plants to the atmosoxygen; its composition differing from that phere, can account for their adoption. of woody fibre in its being richer in carbon. It is known that nitrogen, hydrogen, and Misled by this simplicity in its constitu- a number of other gases, exercise a pecution, physiologists found no difficulty in dis- liar, and in general, an injurious influence covering the mode of the formation of upon living plants.' Is it, then, probable, that woody fibre; for they say,' humus has only oxygen, one of the most energetic agents in to enter into combination with water, in nature, should remain without influence on order to effect the formation of woody fibre, plants when one of their peculiar processes and other substances. similarly composed, of assimilation has ceased? such as sugar, starch, and gum. But they It is true that the decomposition of carforget that their own experiments have suf bonic acid is arrested by absence of light. ficiently demonstrated the inaptitude of these But then, namely, at night, a true chemical substances for assimilation. process commences, in consequence of the At1 the erroneous opinions concerning the action of the oxygen, in the air, upon the modus operandi of humus have their origin organic substances composing the leaves, in the false notions entertained respecting blossoms, and fruit. This process is not at the most important vital functions of plants; all connected with the life of the vegetable analogy, that fertile source of error, having, organism, because it goes on in a dead plant unfortunately, led to the very unapt com- exactly as in a living one. parison of the vital functions of plants with The substances composing the leaves. of those of animals. different plants being known, it is a matter Substances, such as sugar, starch,. &c., of the greatest ease and certainty to calcuwhich contain carbon and the elements of late which of them,'during life, should abwater, are products of'the life of plants sorb most oxygen by chemical action when which live only while they generate them. the influence of light is withdrawn. The same may be said of. humus, for it can The leaves and green parts of all plants be formed in plants like the former sub- containing volatile oils or volatile constitustances. Smithson,.Jameson, and Thomson, ents in general, which change into resin by found that the black excretions of unhealthy the absorption of oxygen, should absorb elms, oaks, and horse chesnuts, consisted of more than other parts which are free front humic acid in combination with alkalies. such substances. Those leaves, also, which Berzelius detected similar products in the'contain either the constituents of nutgalls,'bark of mos.t trees. Now, can'it be supposed or compounds in which nitrogen is present, that the diseased organs of a plant possess''ought to absorb more oxygen than those the power of geinrating the matter to which which do not contain such matters/ The its substance and vigour are ascribed? correctness of these inferences has been disHow does it happen, it may be asked, that tinctly proved by the observations of De the absorption of carbon from the atmos- Saussure; for,'while the tasteless leaves of phere by plants is doubted by all botanists the,/gave americana absorb only 0-3 of and vegetable physiologists, and that by the their volume of oxygen in the dark, during greater number the purification of the air by 24 hours, the leaves of the Pinus.Ibies, means of them is wholly denied? which contain volatile and resinous oils, The action of plants on the air in the absorb 10 times, those of the Quercus Robur absence of light, that is during night, has containing tannic acid 14 times, and the been much misconceived by botanists, and balmy leaves of the Populus alba 21 times from this we may trace most of the errors that quantity. This chemical. action.is which abound in the greater part of their shown very plainly also, in the leaves of writings. The experiments of Ingenhouss the Cotyledon calycinuin, the Cacaliaficoit:es, and others; for they are sour like sorrel in * Meyen, PfJanzenphysiologie, II. S. 141. the morning, tasteless at noon, and bitte::in ASSIMILATION OF CARBON. 19 the evening. The formation of acids is oak wood contains Ay more hydrogen than effected during the night by a true process corresponds to this proportion. In Pinus of oxidation: these are deprived of their Larit, P. Jlbies, and P. picea, the excess of acid properties during the day and evening, hydrogen amounts to ~, and in Tilia euroand are changed by separation of a part of cpcea to -. The quantity of hydrogen stands their oxygen into compounds containing in some relation to-the specific weightof the oxygen and hydrogen, either in the same wood; the lighter kinds of wood contain proportions as in water, or even with an more of it than the heavier. In ebony wood excess of hydrogen, which is the composi- (Diospyros Ebenum) the oxygen and hydrotion of all tasteless and bitter substances. gen are in exactly the same proportion as in Indeed, the quantity of oxygen absorbe water. could be estimated pretty nearly by the dif- The difference between the composition ferent periods which the green leaves of of the varieties of wood, and that of simple plants require to undergo alteration in colour, woody fibre, depends, unquestionably,-upon by the influence of the atmosphere. Those the presence of constituents, in part soluble, which continue longest green will' abstract and in part insoluble, such as resin and less oxygen from the air in an equal space other matters, which contain a large proof time, than those the constituent parts of portion of hydrogen: the hydrogen of such which suffer a more rapid change/ It is, substances being in the analysis of the varifound, for example, that the leaves of the ous woods superadded to that of the true hlex aquifolium, distinguished by the dura- woody fibre. bility of their colour, absorb only 0-86 of It has previously been mentioned that their volume of oxygen gas in the same time mouldering oak wood contains carbon and that the leaves of the poplar absorb 8, and the elements of water, without any excess those of the: beech 9~ times their volume; of hydrogen. But the -proportions of its. both the beech and poplar being remarkable constituents must necessarily have been diffor the rapidity and ease with which the ferent, if the volume of the air had not colour of their leaves changes. - changed during its decay, because the proWhen the green leaves of the poplar, the portion of hydrogen in those component beech, the oak, or the holly, are dried under substances of the wood which contained it the air pump, with exclusion of light, then in excess is here diminished, and this dimimoistened with water, and placed under a nution could only be effected by an absorpglass globe filled with oxygen, they are tion of oxygen, and consequent formation found to absorb that gas in proportion as of water. they change in colour. The chemical nature Most vegetable physiologists have conof this process is thus completely established. nected the emission of carbonic acid during The diminution of the gas which occurs can the night with the absorption of oxygen only be owing to the union of a large pro- from the atmosphere, and have considered portion of oxygen with those substances these actions as a true process of respiration which are already in the state of oxides, or in plants, similar to that of animals, and like to the oxidation of the hydrogen in those it, having for its result the separation of vegetable compounds which contain it in carbon from some of their constitutents. excess/ The fallen brown or yellow leaves This opinion has a very weak and unstable of the, oak contain no longer tannin, and foundation. those of the poplar no balsamic constituents. The carbonic acid, which has been abThe property which green leaves possess sorbed by the leaves and by the roots, toof absorbing oxygen belongs also to fresh gether with water, ceases to be decomposed wood, whether taken from a twig or from on the departure of daylight; it is dissolved the interior of, the trunk of a tree. When in the juices which pervade all parts of the fine chips of such wood are placed in a plant, and. escapes every moment through moist condition under a jar fillqd with oxy- the leaves in quantity corresponding to that gen, the gas is seen to diminish in volume. of the water which evaporates. But wood, dried by exposure to the atmo- A soil in which plants vegetate vigorsphere and then moistened, converts the ously, contains a certain quantity of moisoxygen into carbonic acid, without change ture which is indispensably necessary to of volume; fresh wood, therefore, absorbs their existence. Carbonic acid, likewise, is most oxygen. always present in such a soil, whether it MM. Petersen and Sch6dler have shown, has been abstracted from the air or has been by the careful elementary analysis of 24 dif- generated by the decay of vegetable matter. ferent kinds of wood, that they contain car- Rain and wellwater, and also that from bon and the elements of water, with the other sources. invariably contains carbonic addition of a certain quantity of hydrogen. acid. Plants during their life constantly Oak wood, recently taken from the tree, and possess the power of absorbing by their dried at 100~ C. (212 F.,) contains 49,432 roots moisture, and, along with' it, air and carbon, 6.069 hydrogen, and 44.499 oxygen. carbonic acid. Is it, therefore, surprising The proportion of hydrogen which is ne- that the carbonic acid should be returned cessary to combine with 44.498 oxygen in unchanged to the atmosphere, along with order to form water, is -1 of this quantity, water, when light (the cause of the fixation namely, 5.t56; it is evident, therefore, that of its carbon) is absent? 20 AGR1CUITURAL CHEMISTRY. Neither this emission of carbonic acid nor guments. How, then, are we to aecouni the absorption of oxygen has any connection for its not being received in its full extent by with the process of assimilation; nor have most other physiologists, for its being even they'the slightest relation to one another; disputed by many, and considered by a few the one- is a purely mechanical, the other a as quite refuted X. purely chemical process. A cotton wick, All this is due to two causes, which we inclosed in a lamp, which contains a liquid shall now consider. saturated with carbonic acid, acts exactly in One is, that in botany the talent and la.the same manner as a living plant in the bour of inquirers has been wholly spent in night. Water and carbonic acid are sucked the examination of form and structure: cheup by capillary attraction, and both evapo- mistry and' physics have not been allowed rate from the exterior part of the wick. to sit in council upon the explanation of the Plants which live in a soil containing hu- mnost simple processes; their experience and mus:exhale much more carbonic acid dur- their laws have not been employed, though ing the night than those which grow in dry the most powerful mneans of help in the ac-'situations; they also yield more in rainy quirement of true knowledge. They have than in dry weather. These facts point out not been used, because their study has been to us the cause of the numerous contradic- neglected. tory observations, which have been made All discoveries in physics and in chemiswith respect to the change impressed upon try, all explanations of chemists must rethe air by living plants, both in darkness main without fruit and useless, because, and in common daylight, but which are un- even to the great leaders in physiology, carworthy of consideration, as they do not bonic acid, ammonia, acids, and bases, are assist in the solution of the main question. sounds without meaning, words without There are other facts which prove in a de- sense, terms of ae unknown language, which, cisive manner that plants yield more oxygen awaken no thoughts and -no associations. to the atmosphere than they extract from it; They treat these sciencqs like the vulgar, these proofs, however, are to be drawn with who despise a foreign literature in exact certainty only from plants which live under proportion to their ignbrance of it; since water. even when they have- had some acquintance When pools and ditches, the bottoms of with them, they have not understood their which are covered with growing plants, spirit and application. freeze upon their surface in winter,' so that Physiologists reject the aid of chemistry the water is completely excluded from the in their inquiry into the secrets of vitality, atmosphere by a clear stratum of ice, small although it alone could guide them in the -bubbles of gas are observed to escape, con- true path; they reject chemistry, because in tinually, during the day, from the points of its pursuit of knowledge it destroys the subthe leaves and twigs. These' bubbles are jects of its investigation; but they forget seen most distinctly when the rays of the that the knife of the anatomist must dissun fall upon the ice; they are very small member the body,. and destroy its organs, if at first, but collect under the ice and form an account is to be given of their form, larger bubbles. They consist of pure oxy- structure, and functions. gen gas. Neither during the night, nor dur- When pure potato starch is dissolved in ing the day when the sun does not shine, nitric acid, a ring of the finest wax remains. are they observed to diminish in quantity. What can be opposed to the conclusion of The source of this oxygen'is the carbonic the chemist, that each grain of starch conacid dissolved in the water, which is ab- sists of concentric layers of wax and amylin, sorbed by the plants, but is again supplied which thus mutually protect each other to the water, by the decay of vegetable sub- against the action of water and ether'? Can stances contained in the soil. If these plants.results of this kind, which illustrate so comabsorb oxygen during the night, it can be in pletely both the nature' and properties of no greater quantity than that which the sur- bodies, be attained by the microscope.'Is rounding water holds in solution, for the it possible to make the gluten in a piece of gas, which has been exhaled, is not again bread visible in all its connections ahd ramiabsorbed. The action of water plants can- fications. It is impossible by means of'innot be supposed to form an exception to a struments; but if the piece of breadis placed great law of nature, and the less so, as the in a lukewarm decoction of malt, the starch, different action of aerial plants upon the at- and the substance called dlextrine, are seen mosphere is very easily explained. to dissolve like sugar in waters and, at last, The opinion is not new that the carbonic nothing remains except the gluten,, in the acid of the air serves for the nutriment of plants, and that its carbon is assimilated by * According to Raspail, starch consists of vesithem; it has been admitted, defended, and cles inclosing within them a fluid resembling gum. argued for, by the soundest and most intelli- Starch may be put in cold water without being gent natural philosophers, namely, by Priest- dissolved: but, when placed in hot water, these lev, Sennebier, De Saussure, and even by spherues burst, and allow: he escape of the liquid. lev- Senn~ebier, De Saussu're, and even by This liquid is the aextr-ine of Biot, so called beIngenhouss himself. There scarcely exists cause it possesses the p;of Bit, so cailed beF theory in natural science, in favour of plane ofpossesses the po perty of turninhthand. theoryothe polarization of light to the right andD. which there are more clear and decisive ar- -ED. ASSIMILATION OF CARBON. 21 form of a spongy mass, the minute pores of plants did not attain to the development of which can be seen only by a microscope. the third small leaf. In other cases, they Chemistry offers innumerable resources allowed the water to penetrate the marble, of this kind which are of the greatest use in from below, yet, in spite of this, they died. an inquiry into the nature of the organs of It is worthy of observation, that they lived plants; but they are not used, because the longer with pure distilled water than with need of them is not felt. The most import- that impregnated with carbonic acid; but ant organs of animals and their functions still, in this case also, they eventually peare known, although they may not he visi- rished. Other experimenters sowed seeds ble to the naked eye. But in vegetable phy- of plants in flowers of sulphur and sulphate siology, a leaf is in every case regarded of barytes, and tried to nourish them with merely as a leaf, notwithstanding that leaves carbonic acid, but without success. generating oil of turpentine or oil of lemons Such experiments have been considered must possess a different nature from those as positive proofs, that carbonic acid will in which oxalic acid is formed. Vitality, in not nourish plants; but the manner in which its peculiar operations, makes use of a spe: they were instituted is opposed to all rules cial. apparatus for each function of an organ. of philosophical inquiry, and to all the laws A rose twig engrafted upon a lemon tree of chemistry. does not bring forth lemons, but roses. Many conditions are necessary for the Vegetable physiologists in the study of their life of plants; those of each genus require science have not directed their attention to special conditions; and should but one of that part of it which is most worthy of in- these be wanting, although the rest be sup-, vestigation. plied, the plants will not be brought to maThe second cause of the incredulity with turity. The organs of a plant, as well as which physiologists; view the theory of the those of an animal, contain substances' of nutrition of plants by the carbonic acid of the most different kinds; some are formed the atmosphere is, that the art of experi- solely of carbon and the elements of water, menting is not known in physiology, it being others contain nitrogen, and in all plants we an art which can be learned accurately only find metallic oxides in the state of salts. in the chemical laboratory. Nature speaks,The food which can serve for the producto us in a peculiar language, in the language tion of all the organs of a plant, must necesof phenomena; she answers at all times the sarily contain all its elements. These most questions which are put to her; and such essential of all the chemical qualities of nuquestions are experiments. An experiment triment may be united in one substance, or is the expression of:a thought: we are near they may exist separately in several; in the truth when the phenomena elicited by which case, the one contains what is wantthe experiment corresponds to the thought; ing in the other. Dogs die although fed while the opposite result shows that the with jelly, a substance which contains niquestion was falsely stated, and that the.trogen; they cannot live upon white bread, conception was erroneous. sugar or starch, if these are given as food, The critical repetition of another's experi- to the exclusion of all other substances. ments must be viewed as a criticism of his Can it be concluded from this, that these opinions; if the result of the criticism be substances contain no elements suited for merely negative, if it do not suggest more assimilations Certainly not. correct ideas in the place of those which it Vitality is the power vwhich each organ is intended to refute, it should be disre- possesses of constantly reproducing itself; garded; because the worse experimenter the for this it requires a supply of substance. critic is, the greater will be the discrepancy which contain the constituent elements between the results he obtains and the views of its own substance, and are capable proposed by the other. of undergoing transformation. All the It is too much forgotten by physiologists, organs together cannot generate a single that their duty really is not to refute the ex- element, carbon, nitrogen, or a niitallic' periments of' others, nor to show that they oxide. are erroneous, but to discover truth, and When the quantity of the food is too that alone. It is startling, when we reflect great, or is not capable of undergoing the that all the time and energy of'a multitude necessary transformation, or.exerts any peof persons of genius, talent, and knowledge, culiar chemical action, the organ itself is are expended in endeavours to demonstrate subjected to a change: all poisons act in this each other's errors. manner. The most nutritious substances The question whether carbonic acid is the may cause death. In experiments such as food of plants or not has been made the sub- those described above, every condition of ject of experiments with perfect zeal and nutrition should be considered. Besides good faith; the results have been opposed those matters which form their principal to that view. But how was tne inquiry in- constituent parts, both animals and plants stituted? require others, the peculiar' functions of The seeds of balsamines, beans, cresses, which are unknown. These are inorganic and gourds, were sown in pure Carrara sabstances, such as common salt, the total marble, and sprinkled with water containing want of which is in animals inevitably procarbonic adid, ThB seeds sprang, but the ductive of death. Plants, fdr the sgame rna 22: AGRICULTURAL CHEMISTRY. son, cannot live unless supplied with cer- out the aid of some substance contalirng nltain metallic compounds. trogen, which is an essential constituent of If we knew with certainty that there ex- the sap, and indispensable for its producisted a substance capable alone of nour- tion? Must the plant not die, however ishing a plant and of bringing it to maturity, abundant the supply, of carbonic acid may we might be led to a knowledge of the Con- be, as soon as the first small leaves have ditions necessary to the life of all plants, by exhausted the nitrogen contained in'the studying its characters and composition. If seeds? humus were such a substance, it would Can a plant be expected to grow in Carhave precisely the same value as the only rara marble, even when an azotised subsingle food which nature has produced for stance is supplied to it, if the marble be animal organization, namely, milk (Prout.) sprinkled with an aqueous solution of carThe constituents of milk are cheese or bonic acid, which dissolves the lime and caseine, a compound containing nitrogen in forms bicarbonate of lime? A plant of the large proportion; butter, in which hydrogen family of the Plumbaginece, upon the leaves abounds; and sugar of milk, a substance of which fine hornlike, or scaly processes with a large quantity of hydrogen and oxy- of crystallised carbonate of lime are formed, gen in the same proportion as in water. It might, perhaps, attain maturity under such also contains in solution, lactate of soda, circumstances; but.these experiments, are phosphate of lime, and common salt; and a only sufficient to prove, that cresses, gourds, peculiar aromatic product exists in the but- and balsamines, cannot be nourished by ter, called butyric acid. The knowledge of bicarbonate of lime, in the absence of matthe composition of milk is a key to the con- ter containing nitrogen. We may, indeed, ditions necessary for the purposes of nutri- conclude, that the salt of lime acts as a tion of all animals. poison, since the developement of plants All substances which are adequate to the will advance farther in pure water, when nourishment of animals contain those ma- lime and carbonic acid are not used. terials united, though not always in the Moist flowers of sulphur attract oxygen same form; nor can any one be wanting for from the atmosphere, and become acid. Is a certain space of time, without a marked it possible that a plant can grow and flourish effect on the health being produced. The in presence of free sulphuric acid, with no employment of a substance as food presup- other nourishment than carbonic acid? It is poses a knowledge of its capacity of assimi- true, the quantity of sulphuric acid formed lation, and- of the conditions under which thus in hours, or in days, may be small, but this takes:place. the property of each particle of the sulphur A carnivorous animal dies in'thevacuum to absorb oxygen and retain it, is present of an air pump, even though supplied with every moment. a superabundance of food; it dies in the air, When it is known that plants require if the demands of its stomach are not satis- moisture, carbonic acid, and air, should we fled; and it dies in pure oxygen gas, how- choose as the soil for experiments on their ever lavishly nourishment be given to it. Is growth, sulphate of barytes, which, from its it hence to be concluded, that neither flesh, nature and specific gravity, completely prenor air, nor oxygen, is fitted to support life? vents the access of air? Certainly not. All these experiments are' valueless for the From the pedestal of the Trajan column decision of any question. It is absurd to at Rome we might chisel out each single take for them any soil, at mere hazard, as piece of stone, if upon the extraction of the long as we are ignorant of the functions second we replaced the- first. But could we performed in plants by those inorganic subconclude from this that the column was sus- stances which are apparently foreign to pended in the air, and- not supported by a them. It is quite impossible to mature a single piece of its foundation? Assuredly plant of the family of the Graminece, or of not. Yet the strongest proof would have the Equisetacece, the solid framework of been given that each portion of the pedestal which contains silicate of potash, without could be removed, without the downfall of silicic acid and potash, or a plant of the gethe column. nus Oxalis without potash, or saline plants Animal and vegetable physiologists, how- such as the. saltworts (Salsola and Salicornia) ever, come to such conclusions with re- without chloride of sodium, or at least some spect to the process of assimilation. They salt of similar properties. All seeds of the institute experiments, without being ac- Graminecw contain phosphate of magnesia; quainted with the circumstances necessary the solid parts of the roots of the althaea confor the continuance of life-with the quali- tain more phosphate of lime than woody fibre. ties and proper nutriment of the animal or Are these substances merely accidentally plant on which they operate-or with the present? A plant should not be chosen for nature and chemical constitution of its experiment, when the matter which it reorgans. These experiments are considered quires for its assimilation is not well known. by them as convincing proofs, while they What value, now, can be attached to exare fitted only to awaken pity. periments in which all those matters which Is it possible to bring a plant to maturity a plant requires in the process of assimilaby means of carbonic acid and water, with- tion, besides its mere nutriment, have been ORIGIN AND ACTION OF HUMUS. 23 excluded'with the greatest care? Can the A very long time is required for the comlaws of life be investigated in an organised pletion of this process of combustion, and the being which is diseased or dying? presence of water is necessary for its mainThe mere observation of a wood or mea- tenance: alkalies promote it, but acids redow is infinitely better adapted to decide so tard it; all antiseptic substances, such as simple a question than all the trivial experi- sulphurous acid, the mercurial salts, empyments under a glass globe; the only dif- reumatic oils, &c., cause its cormplete cesference is that instead of one plant there are sation. thousands., When we are acquainted with Woody fibre in a state of decay is the the nature of a single cubic inch of their substance called humus.scil, and know the composition of the air The property of woody fibre tf,,nvert and rainwater, we are in possession of all surrounding oxygen gas into carbohic acid the conditions necessary to, their life. The diminishes in proportion as its decay adsource of the different elements entering into vances, and at last a certain quantity of a the composition of plants cannot possibly brown coaly-looking substance remains, in escape us, if we know in what form they which this, property is entirely, wanting. take up their nourishment, and compare its This substance is called mould; it is the composition with that of the vegetable sub- product'of the complete decay of woody stances which compose their structure. fibre. Mould constitutes the principal of all All these questions will now be examined the strata of brown coal and peat. and discussed. It has been already shown Humus acts in the same manner in a soil that the carbon of plants is derived from the permeable to air as in the air itself; it is a atmosphere: it still remains for us to in- continued source of carbonic acid, which it quire what power is exerted on vegetation emits very slowly. An atmosphere of carby the humus of the soil and the inorganic bonic acid, formed at the expense of the air, constituents of plants and also to trace the surrounds every particle of decaying humus. sources of their nitrogen.' The-cultivation of land, by tilling and loosening the soil, causes a free and unobstructed access of air. An atmosphere of carbonic acid is, therefore, contained in every CHAPTER III. fertile soil, and is the first and most important food for the young plants which grow ON THE ORIGIN AND ACTION OF HUMUS. in it. In spring, when those organs of plants IT will be shown in the second part of are absent which nature has appointed for this work, that all plants and vegetable the assumption of nourishment from the structures undergo two processes of decom- atmosphere, the component substance of the position after death. One of these is named seeds is exclusively employed in the formafermnentation; the other, putrefaction, decay, tion of the roots. Each new radicle fibril or eremacausis.*' which a plant acquires may be regarded as It will likewise be shown, that decay is a constituting at the same time a mouth, a slow process of combustion, —a process, lung, and a stomach. The roots perform therefore, in which the combustible parts of the functions of the leaves from the first a plant unite with the oxygen of the atmo- moment of their formation: they extract sphere.'from the soil their proper nutriment, namely, The decay of woody fibre (the principal the carbonic.acid generated by the humus. constituent of all plants) is accompanied by By loosening the soil which surrounds a phenomenon of a peculiar kind. This young plants, we favour -the access of air, substance, in contact with air or oxygen and the formation of carbonic acid; and, on gas, converts the latter into an equal volume the other hand, the quantity of their food of carbonic acid, and. its decay ceases upon is diminished by every difficulty which opthe disappearance of the oxygen. If the poses the renewal of air. A plant itself carbonic acid is removed, and oxygen re- effects this change of air at a certain period placed, its decay recommences, that is, it of its growth. The carbonic acid, which again converts oxygen into carbonic acid. protects the undecayed humus from farther Woody fibre consists of carbon and the ele- change, is absorbed and taken away by the ments of water; and if we judge only from fine fibres of the roots, and by the roots the products formed during its decomposi- themselves; this is replaced by atmospheric lion, and from those formed by pure char- air, by which process the decay is renewed, coal, burned at a high temperature, we and a fresh portion of carbonic acid formed. might conclude that the causes were the A plant at this time receives. its food both same in both: the decay of woody fibre pro- by the roots and by the organs above ground, ceeds, therefore, as if no hydrogen or oxy- and advances rapidly to maturity. gen entered into its composition. When a plant is quite matured, and when * The word eremacausis was proposed by the author some time since, in order to explain the * The humic acid of chemists is a product of the true nature of decay; it is compounded from decomposition of humus by alkalies; it does not ai-, lby place it. What these relations are, it duce itself, as the stomach of a dead calf; remains for physiologists to investigate. both are, unquestionably, destitute of life. Truly it would be extraordinary if this vital But when amylin or starch is introduced' principle, which uses every thing forits own into a decoction of malt, it changes, first:purposes, had alloted no share to chemical into a gummy-like matter, and. lastly into forces, which stand so freely at its disposal. sugar. Hard-boiled albumen and muscular We shall obtain that which is obtainable in fibre can be dissolved in a decoction of a a rational inquiry into nature, if we secalf's stomach, towhich a few drops of mu-. parate the actions belonging'to chemical riatic acid have been added, precisely as in powers from those which are subordinate to the stomach itself.~ (Schwann, Schulz.) other influences. But the expression " vital The power, therefore, to effect transfor- principle" must in the mean time be consimations, does not belong to the vital prin- dered as of equal value with the terms speciple: each transformation is owing to a cific or dynamic in medicine: every thing is disturbance in the attraction of the elements specific'which we cannot explain, and of a compound, and is consequently a dynamic is the explanation of all which we purely chemical process. There is no doubt do not understand; the terms having been that this process takes place in another form invented merely for the purpose of concealfrom that of the ordinary decomposition of ing ignorance by the application of learned salts, oxides, or sulphurets. But is it the epithets. fault of chemistry that physiology has hith- Transformations of existing compounds erto taken no notice of this new form of are constantly taking place during the whole chemical action? life of a plant, in consequence of which. Physicians are accustomed to administer and as the results of these transformations, whole ounces of borax to patients suffering there are produced gaseous matters which under urinary calculi, when it is known are excreted by the leaves and blossoms, solid that the bases of all alkaline salts formed by excrements deposited in the bark, and fluid organic acids are carried through the urinary soluble substances which are eliminated by passages in the form of alkaline carbonates, the roots. Such secretions are most abuncapable of dissolving calculi (Wohler.) Is dant immediately before the formation and this rational? The medical reports state, during the continuance of the blossoms; that upon the Rhine, where so much cream they diminish after the development of the of tartar is consumed in wine, the only cases fruit. Substances containing a large proporof calculous disorders are those which are tion of carbon are excreted by the roots and imported from other districts. We know absorbed by the soil. Through the expulthat the uric acid calculus is transformed sion of these matters unfitted for nutrition, the soil receives again with usury, the carconsideration, that the most approved remedies bon which it had at first yielded to the for counteracting or stopping the progress of this young plants as food, in the form of carfrightful malady are precisely those which are bonic acid. found most efficacious` in retarding putrefaction. The soluble matter thus acquired by the Thus, it is well known that much relief is afforded soil is still capable of decay and utrefaction, by a lesidcnce in works in which empyreumatic- soil is still capable of decay and putrefaction, by a residence in works in which empyreumatic oils are manufactured by dry distillation, such as and by undergoing these processes furnishes manufactories fbr the preparation of gas or sal-am- renewed sources of nutrition to another genemoniac. For the same reason, the respiration of ration of plants; it becomes humus. The cultiwood vinegar (pyroligneous acid,) of chlorine, and- vated soil is thus placed in a situation exactly means of the acids, hadis been recognized as a analogous to that of forests and meadows, means of alleviating the disease.. *This remnarkable action has been completely for the leaves of trees which fall in the forest confirmed in this laboratory (Giessen,) by Dr. in autumn, and the old roots of grass in the.Vow,' a highly distinguished yiaung physioltgist, myadow, a'e likewise convere'd intb humus ORGANIC CHEMICAL PROCESSES. 27 by the same influence: a soil receives more which in consequence of revolutions of the carbon in this form than its decaying humus same kind occurring in later ages have unhad lost as carbonic acid. dergone the same changes, we never find Plants do not exhaust the carbon of a soil. their roots absent. in the normal condition of their growth; on The verdant.plants of warm climates are the contrary, they add to its quantity. But very often such as obtain from the soil only if it is true that plants give back more car- a point of attachment, and are not dependent bon to a soil than they take from it, it is evi- on it for their growth. How extremely dent that their growth must depend upon the small are the roots of the Cactus, Sedum, reception of nourishment from the atmo- and Sempervivum, in proportion to their sphere in the form of carbonic acid. The mass,; and to the surface of their leaves'! influence of humus upon vegetation is ex- Large forests are often found growing in plained by the foregoing facts in the most soils absolutely destitute of carbonaceous clear and satisfactory.manner. matter; and the extensive prairies of the Humus does not nourish plants by being western continent show that the carbon taken up and assimilated in its unaltered necessary for the sustenance of a plant may state, but by presenting a slow and lasting, be entirely extracted from the atmosphere. source of carbonic acid, which is absorbed Again, in the most dry and barren sand, by the roots, and is the principal nutriment where it is impossible for nourishment to be of young plants at a time when, being des- obtained through the roots, we see the milkytitute of leaves, they are unable to extract juiced plants attain complete perfection. food from the atmosphere.' The moisture necessary for the nutrition of In'former periods of the earth's history, these plants is derived'from the atmosphere, its surface was covered with plants, the re- and when assimilated is secured from evamains of which are still found in the coal. poration by- the nature of the juice itself. formations. These plants-the gigantic. Caoutchouc and wax, which are formed in monocotyledons, ferns, palms, and reeds- these plants, surround the water, as in oily belong to a class to which nature has given emulsions, with an impenetrable envelope the power, by means of an immense exten- bywhich the fluid is retained, in the samne sion of their leaves, to dispense with nour- manner as milk is prevented from evaporatishment from the soil. They resemble in ing by the skin which forms upon it. this respect the, plants which we raise from These plants, therefore, become turgid. with bulbs and tubers, and which live while their juices. young upon the substances contained in Particular examples might be cited of their'seed, and require no food from the soil plants, which have been brought to maturity, when their exterior organs of.nutrition are upon a small scale, without the assistance formed. This class of plants is even at of mould; but fresh proofs of the accuracy present ranked'amongst' those which do not of our theory respecting the origin of carbon exhaust the soil. would be superfluous and useless, and The necessity of the existence of plants could not render more striking, or more consuch as these at the commencement of ve- vincing, the arguments already adduced.. It getation, must now be apparent. Humus must not, however, be left unmentioned, is a product of the decay of vegetable mat- that common wood charcoal, by virtue ter, and therefore could not have existed merely of its ordinary well-known properto supply the first plants with the food neces- ties, can completely replace vegetable mould sary for the development of the more deli- or humus. The experiments of Lukas, cate kinds.'Hence the plants capable of which are appended to this work, spare me flourishing under, such circumstances could all further remarks upon its efficacy. only be those which receive their nourish- Plants thrive in'powdered charcoal, and ment from the air alone. By their decay, may be brought to blossom and bear fruit if however, the soil in which they grew be- exposed to the influence of the rain and the came supplied with vegetable matter, and atmosphere; the charcoal may be previously the progress of vegetation must have fur- heated to redness. Charcoal is the most nished to the earth materials adapted for the "indifferent" and most unchangeable subdevelopment of those plants, which depend stance known; it may be kept for centuries upon the nutriment contained in the soil, without change, and is, therefore, not subuntil those organs are formed which are des- ject to decomposition. The only substances tined for the assumption of nourishment which it can yield to plants are some salts, from the atmosphere. which it contains, amongst which is silicate The plants of every former period are dis- of potash. It is known, however, to postinguished from those of the present by the sess the power of condensing gases within ineonsiderable development.of their roots. its pores, and particularly. carbonic acid. Fruit, leaves, seeds, nearly every part of the And it is by virtue of this power that, the plants of a former world, except the roots, roots of plants are supplied.in charcoal, exare found in the brown coal formation. The actly as in humus, with an' atmosphere of vascular bundles, and the perishable cellular carbonic acid and air, which is renewed as tissues of which their roots consisted, have quickly as it is abstracted. been the first to suffer decomposition. But In charcoal powder, which had been used wh~en we' examine oaks and other tred, for this purps'e by Lukas for s'veral yeats, 28 AGRICULTURAL CHEMISTRY. Buchner found a brown substance soluble oxvgeniveighs 3.157 lbs., and 2865 lbs. of in alkalies. This substance was evidently oxygen correspond to 908 cubic metres, or due to the secretions from the roots of the 32,007 cubic feet. plants which grew in it. An acre of meadow, wood, or cultivated A plant placed in a closed vessel in which land in general. replaces, therefore, in the the air, and'the'refore the'carbonic acid, can- atmosphere as much oxygen as is exhausted not be renewed, dies exactly as it would do by 10 cwts. of carbon, either in its ordinary in the vacuum, of an air-pump, or in an at-. combustion in the air or in the respiratory mosphere of nitrogen or carbonic acid, even process of animals. though its roots be fixed in.the richest mould. It has been mentioned at a former page Plants do' not, however, attain maturity, that pure woody.fibre' contains carbon and under ordinary circumstances, in.charcoal the component parts of.water, but that ordipowder, when they are moistened with pure nary wood contains more hydrogen than distilled water. instead of rain or river water. corresponds to ihis proportion. This excess Rain water miust, therefore, contain within' is owing to the presence of the green princi. it one of the essentials of vegetable life; and ple of the leaf, wax, resin, and other bodies it will be shown, that this is the presence of rich in hydrogen. Water must be decoma compound containing nitrogen, the exclu- posed, in. order to furnish the excess of this sion of which entirely deprives humus and element, and consequentlyone equivalent of charcoal of their influence upon vegetation, oxygen must be given back to theatmosphere for every equivalent of hydrogen appropriated by a plant to the production of those substances. The quantity of' oxygen thus set at CHAPTER IV. liberty cannot be insignificant, for the at — mosphere must receive 989 cubic feet of ON THE ASSIMILATION OF HYDROGEN. oxygen for every pound of hydrogen assimilated. THE atmosphere contains the principal It has already been stated, that a plant, in food of plants in the form of carbonic acid, the formation of woody fibre, must always in the state, therefore, of an oxide. The yield to the atmosphere the same proporsolid part of plants (woody fibre) contains'tional quantity of oxygen; that the volume' carbon and the constituents of water, or the of this gas set free would be the same elements of carbonic acid, together with a whether it were-due to the decomposition of certain quantity of hydrogen. It has for- carbonic acid or of water. A little consimerly been mentioned that water consists of deration will-show that this must be the case. the two gases, oxygen and hydrogen. The It has repeatedly been stated, that woody range of affinity possessed by both these'fibre contains carbon in combination with elements Is so extensive that numerous oxygen and hydrogen in the same proporcauses occur which effect the decomposition tion in which they exist in water. Water of water. Indeed, there is'no compound contains 1 equivalent of each element, whilst which plays a more general or more im- carbonic acid consists of 1 equivalent of portant part in the phenomena of combina- carbon, united to 2 equivalents of oxygen. tion and decomposition. We can conceive In the formation of woody fibre, 2 equivathe wood to arise from a combination of the lents of oxygen' must therefore be libecarbon of the carbonic acid with the elements rated. - The woody fibre can only be of water, under the influence of solar light. formed in one of two ways: either the carIn this case, 72.35parts ofoxygen,byweight, bon of carbonic acid unites directly with mist be separated as a gas for every 27.65 water, or the hydrogen of water combines parts of carbon, which are assimilated by a with the oxygen of the carbonic acid. In plant; for this is the composition of carbonic the former of these cases, the two equivaacid in 100 parts. Or, what is muchmore lents of oxygen in the carbonic acid must be probable, plants, under the same'circum- liberated; in the latter, two atoms of water stances, may decompose water, the hydro- must be decomposed, the hydrogen of which gen of which is assimilated along with car- unites with the oxygen of the carbonic acid, bonic acid, whilst its oxygen is separated. whilst the oxygen of the water, thus set If the latter change, takes' place, 8.04 parts free, is disengaged in the state-.of a gas. It of hydrogen must unite with 100 parts of was considered most probable that the latter carbonic acid; in order to form woody fibre, was the case. and the 72.35 parts by weight of oxygen, From.their generating caoutchouc, wax, which was in combination with the hydro- fats, and volatile oils containing hydrogen gen of the water, and which exactly corre- in large quantity, and no oxygen, we may sponds in quantity with the oxygen contained be certain that plants possess the property in the carbonic acid, must be separated in a of decomposing water, because from no gaseous form. other body could they obtain the hydrogen Each acre of land, which produces 10 of those matters. It has:also been proved cwts. of carbon, gives annually to the at- by the observations of Humboldt on the mosphere 865 lbs. of free oxygen gas. The fungi, that water may be decomposed withspecific weight of oxygen is expressed by -out the assimilation of hydrogen. Water is. the number 1.1026; hence 1 cubic metre of a remarkable combination of two elements, ASSIMILATION OF HYDROGEN. 29 which have the power to separate them- The green resinous principle of rthe leaf selves from one another, in innumerable diminishes in quantity, while oxygen is abprocesses, in a manner imperceptible to our sorbed, when fruits are ripened in the dark; senses; while carbonic acid, on the contrary, red and yellow colouring matters are formed; is only decomposable by violent chemical tartaric, citric, and tannic acids disappear, action. and are replaced by sugar, amylin, or gum. Most vegetable structures contain hydro- 6 eq. Tartaric Jcid, by absorbing 6 eq. gen in the form of water, which can be sepa- oxygen from the air, form Grape Sugar, rated as such, and replaced by other bodies; with the separatidn of 12 eq. carbonic acid: but the hydrogen which is essential to their 1 eq. Tannic A1cid, by absorbing 8 eq. oxyconstitution cannot possibly exist in'the state gen from the air, and 4 eq. water, form 1 of water. eq. of.Jmylin, or starch, with separation of All the hydrogen necessary for the forma- 6 eq. carbonic acid. tion of an organic'compound is supplied to We can explain, in a similar manner, the a plant by the decomposition of water. The formation of all the component substances' process of assimilation, in its most simple of plants which contain no nitrogen, whether form, consists in the extraction of hydrogen they are produced from' carbonic acid and from water, and carbon'from carbonic acid, water, with separation of oxygen, or by the in consequence of which, either all the oxy- conversion of one substance into the other, gen of the water and carbonic acid is sepa- by the assimilation of oxygen and separation rated, as in the formation of caoutchouc, the of carbonic acid.'We do not know in what volatile oils which con'tain no oxygen, and form'the production of'these constituents other similar substances, or only a part of it takes place;' in this respect, the representais exhaled. tion of their formation which we have given The known composition of the organic must not be received in an absolute sense, compounds most generally present in vege- it being intended only to render the nature tables, enables us-to state in definite propor- of the process more capable of apprehension; tions the quantity of oxygen separated during but it must not be forgotten, that if the contheir formation. version of tartaric acid into sugar, in grapes, 36 eq. carbonic acid and~ - -be considered as a fact, it must take place 22 eq. hydrogen derived — Woody Fibre, under all circumstances in the same proporfrom 22 eq. water.? tions. with the separation of 72'eq. oxygen. The vital process in plants is, with refer36 eq. carbonic acid and) ~ence. to the point we have been considering, 36 eq. hydrogen derived - Sugar from 36 eq. water,' the very reverse of the chemical processes "with the separation of 72 eq. oxygen. engaged in the formation of salts. Carbonic 36 eq. carbonic acid and acid, zinc, and water, when brought into 30'eq. hydrogen derived -- Starchi, contact, act upon one another, and hydrogen from 30 eq. water Z, is separated, while a white'pulverulent 36 with the separation of eq. oxygen. compound is formed, which contains car36 cq. carbonic acid and 16 eq. hydrogen derived ~ Tanqnic Actd, bonic acid, zinc, and the oxygen of the from 16 eq. water. water. A living plant represents the zinc with the separation of 64 eq. oxygen. in this process: but the process of assimila36 eq. carbonic acid' and)' tion gives rise to compounds, which contain 18 eq. hydrogen derived Tartaric Acid, the elements of carbonic acid and the hydrofrom 18 eq.' water w~ithl the separation of 45 eq. oxygn gen of water, whilst oxygen is sepcarated. 36 eq. carbonic acid and' Decay has been described above as the 18 eq. hydrogen derived.= —alic Acid, great operation of nature, by which that from 18 eq. water. oxygen,'which was assimilated by plants with the separation of 54 eq. oxygen. during life, is again returned to the atmo36 eq. carbonic acid and) from 24 eq. waterived Oil of plants appropriate carbon in the form of c arwith the separation of 84 eq. oxygen'. ~ bonic acid, and hydrogen from the decomposition of water, the oxygen of which is It will readily be perceived that the for- iset free, together with a part of all that conmation of the acids is accompanied with the tained in the carbonic acid. In the process' smallest separation of oxygen; that the of putrefaction, a quantity of water, exactly amnount ofoxygen set free'increases.with the corresponding to' that of the hydrogen, is production of the so-named neutral sub- again formed by extraction of oxygen from stances, and reaches its maximum in the the air; while all the oxygen of the organic formation of the oils. Fruits remain acid'matter is returned to the atmosphere in the in cold summers; while the most numerous form of carbonic acid. Vegetable matters trees under the'tropics are those which pro- can emit carbonic acid, during their decay, duce oils, caoutchouc, and other substance's only in proportion to the quantity of oxygen containing very little oxygen. The action which they contain; acids, therefore, yield of sunshine and influence of heat upon the more carbonic acid than neutral compounds; ripening of fruit is thus, in a. certain mea- while fatty acids, resin, and wax, do not sure, represented by the' numbers above putrefy; they remain in the soil without any cited. apparent change. B2 30 AGRICULTURAL CHEMISTRY. The numerous springs which emit car- surning the most various and opposite forms bonic acid in the neighbourhood of extinct Formate of ammonia changes, under the volcanoes, must be regarded as another influence of a high temperature, into hymeans of compensating for the carbonic acid drocyanic acid and water, without the sepaabsorbed and retained by plants during life, ration of anyofits elements. Ammonia forms and consequently as a source by which oxy- urea, with cyanic acid, and a series of crysgen is supplied to the atmosphere. Bischof talline compounds, with the volatile oils of calculated that the' springs of carbonic acid mustard and bitter almonds. It changes in the Eifel (a volcanic district near Cob- into splendid blue or red colouring matters, lenz) send into the air every day more than when in contact with the bitterconstituent 110,000 lbs. of carbonic acid, corresponding of the bark of the apple-tree (phloridzin,) to 79,000 lbs. of pure oxygen. with the. sweet principle of the Vatriolaria dealbata (orcin,) or with the tasteless matter of' the IRocella tinctolri (erythirin.) All blue colouring matters which are reddened by acids, and all' red colouring substances CHAPTER V. which are rendered blue by alkalies, contain nitrogen, but not in the form of a base. ON THE' ORIGIN AND ASSIMILATION OF. These facts are not sufficient to establish NITROGEN.' the opinion that it is ammonia which affords all vegetables, without exception, the nitroWE cannot suppose that a plant could gen which enters into the'composition of attain maturity, even in the richest vege- their constituent substances. Considerations table mould, without the presence of matter of another kind, however, give to this opicontaining nitrogen; since, we know that nion a degree of certainty which completely nitrogen exists in every part of the vegetable excludes all other views of the matter. structure. The first and most important Let us picture to ourselves the condition question to be solved, therefore, is: How of a well-cultured farm, so large as to be inand in what form does nature furnish nitro- dependent of assistance from other quarters. gen to vegetable albumen, and gluten, to On this extent of land there is a certain fruits and seeds? quantity of nitrogen contained both in'the This question is susceptible of a very corn and fruit which it produces, and in the simple solution. men and animals which feed upon them, Plants, as we know, grow perfectly well and also in their excrements. We shall in pure charcoal, if supplied at the same suppose this quantity to be known. The time with rain water. Rain water can con- land is cultivated without the importation tain nitrogen only in two forms, either as of any foreign substance containing nitrodissolved atmospheric air, or as ammonia, gen. Now, the products of this farm must which consists of this element and hydro- be exchanged every year -for money,' and gen. Now, the nitrogen of the air cannot other necessaries of life-for bodies, therebe made to enter into combination with any fore, which contain no nitrogen. A certain element except oxygen, even by the employ- proportion of nitrogen is exported with corn ment of the most powerful chemical means. and cattle; and this exportation takes place We have not the slightest reason fbr believ- every year, without the smallest compensainog that the nitrogen of the atmosphere tion; yet after a given number of years, the takes part in the processes of assimilation quantity of nitrogen will be found to have of plants and animals; on the contrary, we increased. Whence, we may ask, comes know that, many plants emit the nitrogen this increase of nitrogen?: The nitrogen in which is absorbed by their roots, either in the excrements cannot reproduce itself, and the gaseous form, or in solution in water. the earth cannot yield it. Plants, and conBut there are on the other hand numerous sequently animals, imust, therefore, derive facts, showing, that the formation in plants their nitrogen from the atmosphere. of substances containing nitrogen, such as It will in a subsequent part of this work gluten, takes place in proportion to the be shown that the last products of the decay quantity of this element which is conveyed and putrefaction of animal bodies present to their roots in the state of ammonia, de- themselves in two different forms. They rived from the putrefaction of animal matter. are in the form of a combination of hydroAmmonia, too; is capable of tandergoing gen and nitrogen-ammonia-in the tempersuch a multitude of transformations, when ate and cold climates, and in that of a comin contact with other bodies, that in this pound containing oxygen-nitic acid-in respect it is not inferior to water, which pos- the tropics and hot. climates. The formasesses'the same property in an eminent de- tion of the latter is preceded by the" producgree. It possesses properties which we do tion of the first. Ammonia is the last pronot find in any other compoundiof nitrogen: duct of the putrefaction of animal bodies; when pure, it is extremely soluble in water; nitric acid is the product of the transformait forms soluble compounds with all the tion of ammonia. A generation of a thouacids; and'when in contact with certain sand million men is renewed every thirty other substances, it completely resigns its vears: thousands of millions of animals character as an a kali, and is capable of as- cease to live and are reproduced, in a much ASSIMILATION OF NITROGEN. 31 shorter -period. Where is the nitrogen ammonia, then ten cubic inches-the quanwhich they contained during life? There is tity usually employed in an analysis-must 1no question'which can be answered with contain only 0.000000048 of a grain. This more positive certainty.'All animal bodies extremely small proportion is absolutely induring their decay yield the nitrogen which appreciable bythe most delicate and-:best they contain to the atmosphere, in the form eudiometer; it might be classed among the of ammonia. Even in the bodies buried sixty errors of observation, even were its quanfeet under ground in the churchVard of the tity ten thousand times igreater.'But the Eglise des Innocens, at Paris, all the nitro- detection of ammonia must be much more gen contained in the adipocire was in the easy when a pound of rain-water is exam state of ammonia. Ammonia is the simplest amined, for this contains all the gas'that of all the compounds'of nitrogen; and: hy- was diffused through 11,471 cubic feet ofair. drogen is the element for which nitrogen If a pound of rain-water contain only ~th possesses the most powerful affinity. of a grain of ammonia, then a field of 26,910 The nitrogen- of putrified animals is con- square feet must receive annually upwards tained in the atmosphere as ammonia, in the of 88 lbs. of ammonia, or 71 lbs. of nitroform of a. gas which is capable of entering gen; for by the observations of Schubler, into combination with carbonic acid and: of which were formerly alluded to,' about forming a volatile salt.'Ammonia in its 770,000 lbs. of rain fall over this surface in gaseous form, as well as all its volatile com- four months, and consequently the annual pounds, is of'extreme solubility'in water. fallmust be 2,310,000 lbs. This is much Ammonia, therefore,: cannot remain long in more nitrogen than is contained in the form the atmosphere, as every shower'of rain of vegetable albumen and gluten, in 2920 must condense it, and convey it to the sur-: lbs. of wood, 3085 lbs. of hay, or 200 cwt. face of the earth. Hence, also, rain-water of beet-root, which are'the yearly produce must at all times contain ammonia, though of such a field; but it is less than the straw, not always in equal quantity. It' must be roots, and grain of corn, which might grow greater in summer than in spring or in win- on the same surface, would contain., ter, because the intervals of time between Experiments made in this laboratory the showers are in summer greater; and (Giessen) with the greatest care and'exactwhen several.wet days occur, the rain of ness have placed the presence of amnmoniathe first must contain more of it than that in rain-water beyond all doubt. It has hi-'of the second. The rain of a thunder storm, therto escaped observation, because no perafter a long-protracted drought, ought for.son thought of searching for it. All the this reason to'contain'the greatest quantity rain-water employed in this inquiry was colwhich is conveyed to the earth at one time. lected 600 paces south-west of Giessen, But we have formerly stated, that all the whilst the wind was blowing in. the direcanalyses of atmospheric air hitherto made tion of the town.. When several hundred have failed to demonstrate the presence of' pounds of it were distilled in a copper still, ammonia, although, according to our view, and the'first two or three pounds evaporated it can never be absent. Is it possible that it with the addition of a little muriatic acid, a could have escaped our most delicate and very distinct crystallisation of sal-ammoniac most exact apparatus? The quantity of ni- was obtained: the — crystals had always a trogen contained in a cubic foot of air is brown or yellow colour. certainly extremely small, but, notwithstand- Ammonia may likewise be always detected ing this, the sum of the quantities of nitro- in snow-water. Crystals of sal-ammoniac gen from thousands and millions of dead animals is more than sufficient to supply all * The advocates of the importance of humus as those living at one time with this element. a nourishment for plants, being driven from their From the tension of aqueous vapour at position by the facts brought forward in the pre150 C. (59h F.)=6,98 lines (Paris mea- ceding chapters, have found in the ammonia of the speci gavity atmosphere an explanation of the manner in which sure,) and from its'known specific gravity humus acquires its solubility, and therefore its ca. at 0o C. (320 F..) it follows' that when the pability of being assimilated by plants. Now, it temperature of the air is 590 F. and the is very true that humic acid is. soluble in ammo. height of the barometer 28", 1 cubic metre nia; but the humic acid of chemists is not con. or 35.3 cubic feet of aqueous vap'odur are tCrained in soils. Were it, so, on treating mould with water we should obtain a dark-coloured socontained in 487 cubic metres, or 17,191 lution of humate of ammonia. But we obtain a cubic feet of air: 35.3 cubic feet of aqueous solution which is entirely devoid of this acid. It vapour weigh about It lb. Consequently, cannot be too distinctly kept in' mind that. umic if we suppose that the air saturated with acid is the product of the decomposition of humus, moisture at 59~ F. - allows all the water by means of caustic alkalies. Again, if the moisture at 590 F. allows all the waterammonia, lime, which it contains in the gaseous form to-fall coloured solutions of humates of ammonia, lime, or magnesia, be poured upon good mould or deo as rain, then 1.1 pound of rain-water must cayed oak-wood (which is nearly pure humus,) and be obtained from every 11,471 cubic feet of allowed to filter, the solutions are observed to pass air. The whole quantity of ammonia con- through quite colourless; they are decolourised tained in the same number of cubic feet will just as if they had been filtered through charcoal. also be returned to the earth in this one Here, then, humus possesses the property of ex. tracting humic acid fromwater; or, in other words, pound of rain-water. But if the 11,471 soils have the power of rendering'humic acid in. cubic feet'of air contain a single grain of soluble, or unfit for assimilation.-ED. 32'AGRICULTURAL CHEMISTR'Y. were obtained by evaporating in a vessel is taken up in the form of ammonia by the with muriatic acid several pounds of snow, rootsof plants, and in that forn applied by which were. gathered from the surface of their organs to the production of the azotised' the ground in March, when the snow had a matters contained in them; This question depth of 10 inches.'Ammonia was set free is susceptible of easy solution by well-known from' these crystals by the addition of hydrate facts.,of lime. The inferior layers of snow which'In the year 1834, I was engaged with Dr. rested upon the ground contained a quantity Wilbrand, professor of botany in. the unidecidedly greater than those which formed versity of Giessen, in an investigation rethe surface. specting the quantity of sugar contained in It is worthy of observation'.that the am- different varieties of maple-trees, which monia contained in rain and' snow water grew upon soils which were not manured. possesses an offensive smell of perspiration We obtained crystallised sugars from all, by and animal excrements,-a factwhich leaves simply evaporating their juices, without the no doubt respecting its origin. addition of any foreign substance;, and we Hiinefield has proved that all the springs unexpectedly made the observation, that a in Greifswalde, Wick, Eldena, and Kosten- great quantity of ammonia was emitted from hagen, contain carbonate and nitrate of am- this juice when mixed with lime, and also monia. Ammoniacal salts have been disco- from the sugar itself during its refinement. veredl in many mineral springs in Kissingen The vessels which hung upon the trees in and other places. The ammonia of these order to collect the juice were watched with salts can only arise from the atmosphere. greater attention, on account. of the susAny one may satisfy himself of the pre- picion that some evil-disposed persons had sence of ammonia in rain by'simply adding introduced urine into them, but still a large a little sulphuric or muriatic acid'to a quan-I quantity iof ammonia- was again found -in tity of rain-water, and evaporating.this the form ofneutral salts. The juice' had no nearly to dryness in a clean porcelain basin.'colour, and had no reaction on that of vegeThe ammonia remains in the residue, in tables.'Similar observations were made upon combination with the acid employed; and the juice of the birch tree; the specimens may be detected either by the addition of a subjected to experiment were taken from a little chloride of'platinum,: or more simply wood several miles distant from any house, by a little powdered lime, which, separates and yet.the clarified juice, evaporated with. the'ammonia, and thus renders its peculiar lime, emitted a strong odour of ammonia. pungent smell'sensible.*' The' sensation In the manufactories' of beet-root sugar, which is perceived upon moistening the many thousand cubic feet of juice are daily'hand with rain-water, so different from that purified'with lime, in order to free it from produced by pure distilled water, and to vegetable albumen and- gluten, and it is which the term softness is vulgarly applied, afterwards evaporated for crystallisation. is also due to the carbonate of ammonia'Every person who has entered such a contained in the former. manufactory must have been astonished at'The ammonia which is removed from the the great'quantity of ammonia which is atmosphere by rain and other causes, is as volatilised along with the steam. This amconstantly.,replaced'by the putrefaction of monia must be contained in the form of an animal and'vegetable matters. A certain ammoniacal salt, because the neutral juice. portion of that which falls'with the rain possesses the same characters as the soluevaporates again with the water, but another tion of such a salt in water; it acquires, portion is,. we suppose, taken up by the namely, an acid reaction during evaporation, roots of plants, and entering into new com- in consequence of the neutral salt being conbinations in the different organs of assimila-'verted by loss of ammonia into an acid salt. tion, produces albumen, gluten,'quinine, The free acid which is.thus formed is a morphia, cyanogen, and -a number of other source of loss to the manufacturers of sugar compounds containing nitrogen. The chemi- from. beet-root, by changing a part of the cal characters of ammonia render it capable sugar' into uncrystallisable grape sugar and of entering into such combinations, and of syrup. undergoing numerous transformations. We The products of the distillation of flowers, have lrow, only to consider whether it really herbs, and roots,. with water, and all extracts of plants made for medicinal purposes, contain ammonia. The unripe, the trans* Since the appearance of' the last edition; this parent, and gelatinous pulp of the almond experiment has been repeated by. many in France, and peach emit much ammonia when treated Germany, America, and England, and the exist. ence of ammonia in the atmosphere has been with alkalies. (Robiquet.) The juice of the completely confirmed. The'assertion that this fresh tobacco leaf contains ammoniacal ammonia possesses the "offensive smell of per- salts. The water which exudes- from a cut spiration and animal. excrements," has been ridi- vine, when evaporated with a few drops of culed by many as fanciful —by none, however, muriatic acid, also yields a gummy deliwho have made the experiment. The experiment -h l uh mois so exceedingly easy to perform, that any one quescent mass, wic evo may convince himself of the accuracy of the state- nia on the addition of lime. Ammonia exisst ment.-ED. in every part of plants, in the roots-(as in ASSIMILATION OF NITROGEN. 33 beet-root,) in the stem (of the maple-tree,) I to a soil, which consists only of sand and and in all blossoms and fruit in an unripe clay, in order to procure the richest crop of condition. maize. The soil itself does not contain the The juices of the maple and birch contain smallest particle of organtc matter, and the both sugar and ammonia, and therefore manure employed is formed only of urate, afford all the conditions necessary for the phosphate, oxalate, and carbonate qf ammonia, formation of the azotised components of the together with a few earthy salts.", branches, blossoms, and leaves, as well as Ammonia, therefore, must have yielded of those which contain no azote or nitrogen. the nitrogen to these plants. Gluten is obIn proportion as the developement of those tained not only from corn, but also from parts advances, the ammonia diminishes in grapes and other plants; but that extracted quantity, and when they are fully formed, from the grapes is called vegetable albumen, the tree yields no more juice. although it is identical in composition and The employment of animal manure in the properties with the ordinary gluten. cultivation of grain, and the vegetables It is ammonia which yields nitrogen to which serve for fodder to cattle, is the most the vegetable albumen, the principal conconvincing proof that the nitrogen of vege- stituent of plants; and it must be ammonia tables is derived from ammonia. The which forms the red and blue colouring quantity of gluten in wheat, rye, and bar- matters of flowers. Nitrogen is not preley, is very different; these kinds of grain sented to wild plants in any other form caalso, even when ripe, contain this compound pable of assimilation. Ammonia, by its of nitrogen in very different proportions. transformation, furnishes nitric acid to the Proust fbund French wheat to contain 12.5 tobacco plant, sun-flower, Chenopodium, and per cent. of gluten; Voget found that the Borago offi.cinalis, when they grow in a Bavarian contained 24 per cent.; Davy ob- soil completely free from nitre. Nitrates tained 19 per cent. from winter, and 24 from are necessary constituents of these plants, summer wheat; from Sicilian 21, and from which thrive only when ammonia is present Barbary wheat 19 per cent. The meal of in large quantity, and when they are also Alsace wheat contains, according to Bous- subject to the influence of the direct rays of singault, 17.3 per cent. of gluten; that of the sun, an influence necessary to effect the wheat crown in the "Jardin des Plantes" disengagement within their stem and leaves 26.7, and that of winter wheat 3.33 per cent. of the oxygen, which shall unite with the Such great differences must be owing to ammonia to form nitric acid. some cause, and this we find in the diffe- The urine of men and of carnivorous rent methods of cultivation. An increase of animals contains a large quantity of nitrogen, animal manure gives rise not only to an in- partly in the form of phosphates, partly as crease in the number of seeds, but also to a urea. Urea is converted during putrefacmost remarkable difference in the proportion tion into carbonate of ammonia, that is to of the substances containing nitrogen, such say, it takes the form of the very salt which as the gluten which they contain. occurs in rain-water. Human urine is the Animal manure, in as far as regards the most powerful manure for all vegetables assimilation of nitrogen, acts only by the containing nitrogen; that of horses and formation of ammonia. One hundred parts horned cattle contains less of this element, of wheat grown on a soil manured with but infinitely more than the solid excrements cow-dung (a manure containing the smallest of these animals. In addition to urea, the quantity of nitrogen,) afforded only 11.95 urine of herbivorous animals contains hipparts of gluten, and 64.34 parts of amylin, puric acid which is decomposed during pu. or starch; whilst the same quantity, grown trefaction into benzoic acid and ammonia. on a soil manured with human urine, yielded The latter enters into the composition of the the maximum of gluten, namely 35.1 per gluten, but the benzoic acid often remains cent. Putrefied urine contains nitrogen in unchanged: for example, in the JLnthoxanthe forms of carbonate, phosphate, and lac- thum odoratum. tate of ammonia, and in no other form than The solid excrements of animals contain that of ammoniacal salts. comparatively very little nitrogen, but this " Putrid urine is employed in Flanders as could not be otherwise. The food taken by a manure with the best results. During the animals supports them only in so far as it putrefaction of urine, ammoniacal salts are offers elements for assimilation to the various formed in large quantity, it may be said ex- organs which they may require fcar their elusively; for under the influence of heat increase or renewal. Corn, grass, and all and moisture, urea, the most prominent in- plants, without exception, contain azotised gredient of the urine, is converted into car- substances. The quantity of food which bonate of ammonia. The barren soil on the animals take for their nourishment, dimicoast of Peru is rendered fertile by means of nishes or increases in the same proportion a manure called Guano, which is collected as it contains more or less of the substances from several islands in the South Sea.5 It containing nitrogen. A horse may be kept is sufficient to add a small quantity of guano sea fowl that remain on them during the breeding * The guano, which forms a stratum several season. See the Chapter on Manures.) feet in thickness upon the surface of these islands, * Boussingault, Ann. de Ch. et de Phys. lxv. p. consists of the putrid excrements of innumerable 319. 5 34 AGR1CLJLTURAL CHEMISTRY. alive by feeding it with potatoes, which con- shrubs, and other wild plants; but this is tain a very small quantity of nitrogen; but not sufficient for the purposes of agricullife thus supported is a gradual starvation; ture. Agriculture differs essentially from the animal increases neither in size nor the cultivation of forests, inasmuch as its strength, and sinks under every exertion. principal object consits in the production The quantity of rice which an Indian eats of nitrogen under any form capable of asastonishes the European; but the fact that similation; whilst the object of forest culture rice contains less nitrogen than any other is confined principally to the production of kind of grain at once explains the circum- carbon. All the various means of culture stance. are subservient to these two main purposes. Now, as it is evident that the nitrogen of A part only of the carbonate of ammonia the plants and seeds used by animals as food which is conveyed by rain to the soil is remust be employed in the process of assimila- ceived by plants, because a certain quantitytion, it is natural to expect that the excre- of it is volatilised with the vapour of water; ments of these animals will be deprived of it only that portion of it can be assimilated in proportion to the perfect digestion of the which sinks deeply into the soil, or which food, and can only contain it when mixed is conveyed directly to the leaves by dew, or with secretions from the liver and intestines. is absorbed from the air along with the carUnder all circumstances, they must contain bonic acid. less nitrogen than the food. When, there- Liquid animal excrements, such as the fore, a field is manured with animal excre- urine, with which the solid excrements are ments, a smaller quantity of matter contain- impregnated, contain the greatest part of ing nitrogen is added to it than has been their ammonia in the state of salts, in a form, taken from it in the form of grass, herbs, or therefore, in which it has completely lost its seeds. By means of manure, an addition volatility; when presented in this condition, only is made to the nourishment which the not the smallest portion of the ammonia is air supplies. lost to the plants; it is all dissolved by water, In a scientific point of view, it should be and imbibed by their roots. The evident the care of the agriculturist so to employ all influence of gypsum upon the growth of the substances containing a large proportion grasses-the striking fertility and luxuriance of nitrogen which his farm affords in the of a meadow upon which it is strewedform of animal excrements, that they- shall depends only upon its fixing in the soil the serve as nutriment to his own plants. This ammonia of the atmosphere, which would will not be the case unless those substances otherwise be volatilized, with the water are properly distributed upon his land. A which evaporates.? The carbonate of amheap of manure lying unemployed upon monia contained in rain-water is decomhis land would serve him no more than his posed by gypsum, in precisely the same neighbours. The nitrogen in it would es- manner as in the manufacture of sal-amcape as carbonate of ammonia into the at- moniac. Soluble sulphate of ammonia and mosphere, and a mere carbonaceous residue carbonate of lime are formed; and this salt of decayed plants would, after some years, of ammonia possessing no volatility is conbe found in its place. sequently retained in the soil. All the gypAll animal excrements emit carbonic acid sum gradually disappears, but its action and ammonia, as long as nitrogen exists in upon the carbonate of ammonia continues them. In every stage of their putrefaction as long as a trace of it exists. an escape of ammonia from them may be The beneficial influence of gypsum and of induced by moistening them with a potash many other salts has been compared to that ley; the ammonia being apparent to the of aromatics, which increase the activity of senses by a peculiar smell, and by the dense the human stomach and intestines, and give white vapour which arises when a solid a tone to the whole system. But plants conbody moistened with an acid is brought near tain no nerves; we know of no substance it. This ammonia evolved from manure is capable of exciting them to intoxication and imbibed by the soil either in solution in madness, or of lulling them to sleep and rewater, or in the gaseous form, and plants pose. No substance canpossibly cause their thus receive a larger supply of nitrogen leayes to appropriate a greater quantity of than is afforded to them by the atmosphere. carbon from the atmosphere, when the other But it is much less the quantity of am- constituents which the seeds, roots, and monia, yielded to a soil by' animal excre- leaves require for their growth are wanting. ments, than the form in which it is presented The favourable action of small quantities of by them, that causes their great influence aromatics upon man, when mixed with his on its fertility. Wild plants obtain more food, is undeniable; but aromatics are given nitrogen from the atmosphere in the form of to plants without food to be digested, and ammonia than they require for their growth, still they flourish with greater luxuriance. for the water which evaporates through their leaves and blossoms, emits, after some time, * It has long been the practice in some parts of a putrid smell, a peculiarity possessed only the country to strew the floors of stables with by such bodies as contain nitrogen. Culti- gypsum. This prevents the disagreeable odour b s osiruarising from the putrefaction of stable manure, by Vated plants receive the same quantity of decomposing the ammoniacal salts which are nitrogen from the atmosphere as trees, formed.-ED. ASSIMILATION OF NITROGEN. 35 It is quite evident, therefore, that the mina or iron are true salts, in which the common view concerning the influence of ammonia is contained as a base. Minerals certain salts upon the growth, of' plants containing alumina or oxide of iron also evinces only ignorance of its cause. possess, in an eminent degree, the remarkThe action of gypsum or chloride of cal- able property of attracting ammonia from cium really consists in their giving a fixed the atmosphere and of retaining it. Vaucondition to the nitrogen-or ammonia quelin, whilst engaged in the trial of a crimiwhich is brought into the soil, and which is nal case, discovered that all rust of iron indispensable for the nutrition of plants. contains a certain quantity of ammonia. In order to form a conception of the effect Chevalier afterwards found that ammonia of gypsum, it may be sufficient to remark is a constituent of all minerals containing that 110 lbs. of burned gypsum fixes as iron; that even hematite, a mineral which much ammonia in the soil as 6880 lbs. of is not at all porous, contains one per cent. horse's urine~ would yield to it, even on the of it. Bouis showed also, that the peculiar supposition that all the nitrogen of the urea odour observed on moistening minerals conand hippuric acid were absorbed by the taining alumina, is partly owing to their explants without the smallest loss, in the form haling ammonia. Indeed, gypsum and of carbonate of ammonia. If we admit with some varieties of alumina, pipe-clay for exBoussingaultt that the nitrogen in grass ample, emit so much ammonia, when moisamounts to Tn — of its weight, then every tened with caustic potash, that even after pound of nitrogen which we add increases they had been exposed for two days, redthe produce of the meadow 100 lbs., and dened litmus paper held over them becomes this increased produce of 100 lbs. is effected blue. Soils, therefore, which contain oxby the aid of a little more than 4 lbs. of ides of iron, and burned clay, must absorb gypsum. ammonia, an action which is favoured by Water is absolutely necessary to effect the their porous condition; they further prevent decomposition of the gypsum, on account the escape of the ammonia once absorbed of its difficult solubility, (1 part of gypsum by their chemical properties. Such soils, requires 400 parts of water for solution) and in fact, act precisely as a mineral acid would also to assist in the absorption ofi the sul- do, if extensively spread over their surface; phate of ammonia by the plants: hence it with this difference, that the acid would pehappens, that the influence of gypsum is netrate the ground, enter into combination not observable on dry fields and meadows. with lime, alumina, and other bases, and In such it would be advisable to employ a thus lose, in a few hours, its property of salt of more easy solubility, such as chloride absorbing ammonia from the atmosphere. of calcium. The addition of burned clay to soils has also The decomposition of gypsum by carbo- a secondary influence; it renders the soil nate of ammonia does not take place instan- porous, and, therefore, more permeable to taneously; on the contrary, it proceeds very air and moisture. gradually, and this explains why the action The ammonia absorbed by the clay or ferof the gypsum lasts for several years. ruginous oxides is separated by every shower The advantage of manuring fields with of rain, and conveyed in solution to the soil. burned clay, and the fertility oF ferruginous Powdered charcoal possesses a similar acsoils, which have been considered as facts tion, but surpasses all other substances in so incomprehensible, may be explained in the power which it possesses of condensing an equally simple manner. They have been ammonia within its pores, particularly when ascribed to the great attraction for water, it has been previously heated to redness. exerted by dry clay and ferruginous earth; Charcoal absorbs 90 times its volume of ambut common dry arable land possesses this moniacal gas, which may be again separated property in as great a degree: and besides, by simply moistening it with water. (De what influence can be ascribed to a hundred Saussure.) Decayed wood approaches very pounds of water spread over an acre of nearly to charcoal in this power; decayed land, in a condition in which it cannot be oak wood absorbs 72 times its volume, after serviceable either by the roots or leaves? having been completely dried under the airThe true case is this:- pump. We have here an easy and satisfacThe oxides of iron and alumina are dis- tory means of explaining still further the protinguished from all other metallic oxides by perties of humus, or wood in a decaying their power of forming solid compounds state. It is not only a slow and constant with ammonia. The precipitates obtained source of carbonic acid, but it is also a by the addition of ammonia to salts of alu- means by which the necessary nitrogen is conveyed to plants. * The urine of the horse contains, according to Nitrogen is found in lichens, which grow Fourcroy and Vauquelin, in 1000 parts, on basaltic rocks. Our fields produce more Urea...... 7 parts. of it than we have given them as manure, Hippurate of sodate 24 " and it exists in all kinds of soils and minerals which were never in contact with or1000 parts. ganic substances. The nitrogen in these t 3Boussingault, Ann. de Ch. et de Phys. t. Ixiii. cases could only have been extracted from page 243. the atmosphere. ;-36 AGRICULTURAL CHEMISTRY. We find this nitrogen in the atmosphere, of soda, and produces sulphate of soda in rain water, and in all kinds of soils, in From this fact follows the rule-that the the form of ammonia, as a product of the quantity, which an acid requires of an alkali decay and putrefaction of preceding genera- for its saturation, may be represented by a tions of animals and vegetables. We find very simple number. likewise that the proportion of azotised mat- It is perfectly necessary to form a proper ters in plants is augmented by giving them a conception of what chemists denominate larger supply of ammonia conveyed in the the-" capacity for saturation of an acid," form of animal manure. before we are able to form a correct idea of No conclusion can then, have a better the functions performed in plants, by their foundation than this, that it is the ammonia inorganic constituents. The power of a of the atmosphere which furnishes nitrogen base to neutralize an acid does not depend to plants. upon the quantity of radical which it conCarbonic acid, water and ammonia, con- tains, but altogether upon the quantity of its tain the elements necessary for the support oxygen. Thus protoxide of iron contains of animals and vegetables. The same sub- 1 eq. of oxygen, and unites with 1 eq. of stances are the ultimate products of the sulphuric acid in forming a neutral salt; but chemical processes of decay and putrefac- peroxide of iron contains 3 eq. of oxygen, tion. All the innumerable products of vi- and requires 3 eq. of the same acid for its tality resume, after death, the original form neutralization. Hence when a given weight from which they sprung. And thus death- of an acid is neutralized by different bases, the complete dissolution of an existing the quantity of oxygen contained in these generation-becomes the source of life for a bases must be the same as is exhibited by iew one. the following scale:501'17 parts of Sulphuric Acid neutralize 258'35 Magnesia Oxygen= 100 647'29 Strontia " =100 CHAPTER VI. 1451.61 Oxide of Silver" = 100 956'8 Barytes " =100 OF THE INORGANIC CONSTITUENTS OF It follows from the law of equivalents, PLANTS. that the quantity of oxygen in a base must stand in a simple relation to the quantity of CARBONIC acid, water and ammonia, are oxygen in an acid which unites with it. By necessary for the existence of plants, be- this is meant, that the quantities in both cases cause they contain the elements from which must either be equal or multiples of each their organs are formed; but other sub- other; for the doctrine of equivalents denies stances are likewise requisite for the forma- the possibility of their uniting in fractional tion of certain organs destined for special parts. This will be rendered obvious by a functions peculiar to each family of plants. consideration of the two following examPlants obtain these subtances from inorganic pies: nature. In the ashes left after the incinera-00 parts of Cyani 100 parts of Cyanic Acid contain 23-26 oxy. tion of plants, the same substances are gen =1. found; although in a changed condition. 100 parts of Cyanic Acid saturate 137'21 parts of Although the vital principle exercises a potash, which contain 23'26 oxygen = 1. great power over chemical forces, yet it 100 parts of Nitric Acid contain 7385 oxygen =5. does so only by directing the way in which 100 parts of Nitric Acid saturate 21440 parts of they are to act, and not by changing the oxide of silver, which contain 1477 oxygen 1. they are to act, and not by changing the laws to which they are subject. Hence In the first of these cases, the relation of when the chemical forces are employed in the oxygen of the base to that of the acid is the processes of vegetable nutrition, they as 1:1; in the second, as 1:5. The capacity must produce the same results which are for saturation of each acid, is, therefore, the observed in ordinary chemical phenomena. constant quantity of loxygen necessary to The' inorganic matter contained in plants neutralize 190 parts of it. must, therefore, be subordinate to the laws Many of the inorganic constituents vary which regulate its combinations in common according to the soil in which the plants chemical processes. grow, but a certain number of them are in-'The most important division of inorganic dispensable to their developement. All subsubstances is that of acids and alkalies. Both stances in solution in a soil are absorbed by of these have a tendency to unite together, the roots of plants, exactly as a sponge imand form neutral compounds, which are bibes a liquid, and all that it contains, withtermed salts. According to the doctrine of out selection. The substances thus. conequivalents, these combinations are always veyed to plants are retained in greater or effected in definite proportions, that is to less quantity, or are entirely separated when say, one equivalent of an acid always unites not suited for assimilation. with one or two equivalents of a base, what- Phosphate of magnesia in combination ever that base may be. Thus 501-/I parts with ammonia is an invariable constituent b-; weight of sulphuric acid unite with 1 eq. of the seeds of all kinds of grasses. It is of potash, and form one eq. of sulphate of contained in the outer horny husk, and is pctash; the same quantity unites with I eq. introduced into bread along with the flour, CONSTITUENTS OF PLANTS. 37 and also into beer. The bran of flour con- In order to understand this subject clearly, tains the greatest quantity of it. It is this it will be necessary to bear in mind that any salt which forms large crystalline concre- -one of the alkaline bases may be substituted tions, often amounting to several pounds in for another, the action of all being the same. weight, in the ccecum of horses belonging Our conclusion is therefore by no means ento millers; and when ammonia is mixed dangered by the existence ot a particular with beer, the same salt separates as a white alkali in one plant, which may be absent in precipitate. others of the same species. If this inference Most plants, perhaps all of them, contain be correct, the absent alkali or earth must be organic acids of very different composition supplied by one similar in its mode of acand properties, all of which are in combi- tion, or in other words, by an equivalent of nation with bases, such as potash, soda, another base. The number of equivalents lime, or magnesia. These bases evidently of these various bases which may be comregulate the formation of the acids, for the bined with a certain portion of acid must diminution of the one is followed by a de- necessarily be the same, and therefore the crease of the other: thus in the grape, for amount of oxygen contained in them must example, the quantity of potash contained remain unchanged under all circumstances in its juice is less when it is ripe than when and on whatever soil they grow. unripe; and the acids, under the same Of course, this -argument refers only to circumstances, are found to vary in a those alkaline bases which in the form of similar manner. Such constituents exist in organic salts form constituents of the plants. small quantity in those parts of a plant in Now, these salts are preserved in the ashes which the process of assimilation is most of plants as carbonates, the quantity of active, as in the mass of woody fibre; and which can be easily ascertained. their quantity is greater in those organs It has been distinctly shown, by the analywhose office it is to prepare substances con- sis of De Saussure and Berthier, that the veyed& to them for assimilation by other nature of a soil exercises a decided influence parts. The leaves contain more inorganic on the quantity of the different metallic oxmatters than the branches, and the branches ides contained in the plants which grow on more than the stemn. The potato plant con- it; that magnesia, for example, was contains more potash before blossoming than tained in the ashes of a pine-tree grown at after it. Mont Breven, whilst it was absent from the The acids found in the different families ashes of a tree of the same species from of plants are of various kinds; it cannot be Mont La Salle, and that even the proportion supposed that their presence and peculiari- of lime and potash was very different. ties are the result of accident. The fumaric Hence it has been concluded, (erroneand oxalic acids in the liverwort, the kinovic ously, I believe,) that the presence of bases acid in the China nova, the rocellic acid in exercises no particular influence upon the the Rocella tinctoria, the tartaric acid in growth of plants: but even were this view grapes, and the numerous other organic correct, it must be considered as a most reacids, must serve some end in vegetable life. markable accident that these same analyses But if these acids constantly exist in vege- furnish proof for the very opposite opinion. tables, and are necessary to their life, which For although the composition of the ashes is incontestable, it is equally certain that of these pine-trees were so very different, some alkaline base is also indispensable, in they contained, according to the analyses of order to enter into combination with the De Saussure, an equal number of equivaacids which are always found in the state of lents of metallic oxides; or, what is the same salts. All plants yield by incineration ashes thing, the quantity of oxygen contained in: containing carbonic acid; all therefore must all the bases was in both cases the same. contain salts of an organic acid.* 100 parts of the ashes of the pine-tree Now, as we know the capacity of satura- from Mont Breven containedtion of organic acids to be unchanging, it Carbonate of Potash. 360 follows that the quantity of the bases united " Lime. 46'34 with them cannot vary, and for this reason " Magnesia 6'77 the latter substances ought to be considered with the strictest attention both by the agri- Quantty of oxygen in the onates 6 culturist and physiologist. Quantity of oxygen in the Potash 0'41 culturist and physiologist. " Lime 733 We have no reason to believe that a plant " " " Magnesia 1'27 in a condition of free and unimpeded growth Sum of the oxygen in the bases 9'01 produces more of' its peculiar acids than it 100 parts of the ashes of the pine from requires for its own existence; hence, a Mont La Salle contained*plant, on whatever soil it grows, must contain an invariable quantity of alkaline bases. * According to the experiments \of Saussure, Culture alone will be able to cause a devia- 1000 parts of the wood of the pine from Mont tion. Brevon gave 11'87 parts of ashes; the same quantity of wood from Mont La Salle yielded 11-28 * Salts of organic acids yield carbonates on in- parts. From this we might conclude that the two cineratlon, if they contain either alkaline or earthy pines, although brought ulp in different soils, yet bases. contained the same quantity of uinorganic elements. D 38 AGRICULTURAL CHEMISTRY. Carbonate of Potash ~ 7'36 These remarkable approximations cannot " Lime ~ 51019 be accidental; and if further examinations confirm them in other kinds of plants, no Sum of the carbonates 58-55 other explanation than that already given Quantity of oxygen in the Potash 0'85 can be adopted. ".... Lime 8'10 It is not known in what form silica, man, ganese, and oxide of iron, are contained in Sum of the oxygen in the bases 8'95 plants; but we are certain that potash, soda, The numbers 9-01 and 8-95 resemble each and magnesia, can be extracted from all other as nearly as could be expected even parts of their structure in the form of salts in analyses made for the very purpose of of organic acids. The same is the case with ascertaining the fact above demonstrated lime, when not present as insoluble oxalate which the analyst in this case had not in of lime. It must here be remembered, that view. in plants yielding oxalic acid, the acid and Let us now compare Berthier's analyses potash never exist in the form of a neutral of the ashes of two fir-trees, one of which or quadruple salt, but always as a double grew in Norway, the other in Allevard (d6- acid salt, on whatever soil they may grow. partement de l'Isere). One contained 50, the The potash in grapes also is more frequently other 25 per cent. of soluble salts. A greater found as an acid salt, viz. cream of tartar, difference in the proportion of the alkaline (bitartrate of potash,) than in the form of a bases could scarcely exist between-two to- neutral compound. As these acids and tally different plants, and yet even here the bases are never absent from plants, and as quantity of oxygen in the bases of both was even the form in which they present themthe same. selves is not subject to change, it may be 100 parts of the ashes of firwood from affirmed that they exercise an important inAllevard contained, according to Berthier, fluence on the developement of the fruits and (Ann. de Chim. et le Phys. t. xxxii. p. seeds, and also on many other functions of 248,) the nature of which we are at present ignoPotash & Soda 16-8 in which 3'42 must be oxygen. rant. Lime. 295' 8.20 a " The quantity of alkaline bases existing in Magnesia 3'2 " 1.20 " -. a plant also depends evidently on this cir-,' cumstance of their existing only in the form 49.5 12'82 of acid salts,-for the capacity of saturation Only part of the potash and soda in these of an acid is constant; and when we see ashes was in combination with organic oxalate of lime in the lichens occupying the acids; the remainder was in the form of place of woody fibre which is absent, we sulphates, phosphates) and chlorides. One must regard it as certain that the soluble ornundred parts of the ashes contain 3-1 sul- ganic salts are destined to fulfil equally impnunc acid, 4'2 phosphoric acid, and 0'3 portant though different functions, so much hydrochloric acid, which together neutralize so that we could not conceive the.complete a quantity of base containing 1-20 oxygen. developement of a plant without their preThis number therefore must be substracted sence, that is, without the presence of their from 12-82. The remainder 11 62 indicates acids, and consequently of their bases. the quantity of oxygen in the alkaline From these considerations we must perbases, combined with organic acids in the ceive, that exact and trustworthy examinafirwood of Allevard. tions of the ashes of plants of the same kind The firwood of Norway contained in 100 growing upon different soils would be of the parts,-" greatest importance to vegetable physiology' and would decide whether the facts above Potash. 141 of which 2-4 would be oxygen.entioned are the results of an unchanging Soda 207 53 mentioned are the results of an unchanging Lime. 12 3' 3.45 " " law for each family of plants, and whether Magnesia'4-35 " 1'69 " " an invariable number can be found to ex-—.- - ---: press the quantity of oxygen-which each 51'45 12'84 species of plant contains in the bases united And if the quantity of oxygen of the with organic acids. In all probability such bases in combination with sulphuric and inquiries will lead to mosl important results; phosphoric acid, viz. 1'37, be again sub- for it is clear that if the I roduction of a cerstracted from. 12'84, 11-47 parts remain as tain unchanging quantity of an organic acid the amount of oxygen contained in the bases is required by the peculiar nature of the which were in combination with organic organs of a plant, and is necessary to its exacids. istence, then potash or lime must be taken up by it in order to form salts with this acid; that if these do not exist in sufficient quan* This calculation is exact only in the case tity in the soil, other bases must supply their where the quantity of ashes is equal in weight for place; and that the progress of a plant must a given quantity of wood; the difference cannot, be wholly arrested when none are present. however, be admitted to be so great as to change Seeds b f the Salsola Kali, when sown in sensibly the above proportions. Berthier has not Seeds f the aso Kli, when oden in mentioned the proportion of ashes contained ihcommon garden soil, produce a plant conthe wood. taining both potash and soda; while the CONSTITUENTS OF PLANTS. 39 plants grown from the seeds of this contain of narcotina. Not a trace of meconic acids only salts of potash, with mere traces of can be discovered in many kinds of opium, muriate of soda. (Cadet.) but there is not on this account an absence The examples cited above, in which the of acid, for the meconic is here replaced by quantity of oxygen contained in the bases sulphuric acid. Here, also, we have an exwas shown to be the same, lead us to the ample of what has been before stated,- for in legitimate conclusion that the developement those kinds of opium where both these acids of certain plants is not retarded by the sub- exist, they are always found to bear a cerstitution of the bases contained in them. tain relative proportion to one another. AtBut it was by no means inferred that any tention to these facts must be very important one base could replace all the others which in the selection of soils destined for the culare found in a plant in its normal condition. tivation of plants which yield the vegetable On the contrary, it is known that certain alkaloids. bases are indispensable for the growth of a Now if it be found, as appears to be the plant, and these could not be substituted case in the juice of poppies, that an organic without injuring its developement. Our in- acid may be replaced by an inorganic, withference has been drawn from certain plants, odt impeding the growth of a plant, we must which can bearwithout injury this substitu- admit the probability of this substitution tion; and it can only be extended to those taking place in a much higher, degree in the plants which are in the same condition. It case of the inorganic bases. will be shown afterwards that corn or vines When roots find their more appropriate can only thrive on soils containing potash, base in sufficient quantity, they will take up and that this alkali is perfectly indispensable less of another. to their growth. Experiments have not These phenomena do not show themselves been sufficiently multiplied so as to enable so frequently in cultivated plants, because us to point out in what plants potash or soda they are subjected to special external condimay be replaced by lime or magnesia; we tions for the purpose of the production of are only warranted in affirming that such particular constituents or particular organs. substitutions are in many cases common. When the soil, in which a white hyacinth The ashes of various kinds of plants contain is growing in a state of blossom, is sprinkled very different quantities of alkaline bases, with the juice of the P7hytolacca decandra, such as potash, soda, lime, or magnesia. the white blossoms assume in one or two -When lime exists in the ashes in large pro- hours a red colour, which again disappears portion, the quantity of magnesia is dimi- after a few days under the influence of sunnished, and in like manner according as the shine, and they become white and colourless latter increases the lime or potash decreases. as before.t The juice in this case evidently In many kinds of ashes not a trace of mag- enters into all parts of the plant, without nesia can be detected. being at all changed in its chemical nature, The existence of vegetable alkalies in com- or without its presence being apparently bination with organic acids gives great either necessary or injurious. But this conweight to the opinion that alkaline bases in dition is not permanent, and when the blosgeneral are connected with the developement soms have again become colourless, none of plants. of the colouring matter remains; and if it If potatoes are grown where they are not should occur that any of its elements were supplied with earth, the magazine of inor- adapted for the purposes of nutrition of the ganic bases, (in cellars, for example,) a true plant, then these alone would be retained, alkali, called Solanin, of very poisonous whilst the rest would be excreted in an alnature, is formed in the sprouts which ex- tered form by the roots. tend towards the light, while not the smallest Exactly the same thing must happen trace of such a substance can be discovered when we sprinkle a plant with a solution of in the roots, herbs, blossoms, or fruits of chloride of potassium, nitre, or nitrate of potatoes grown in fields. (Otto.) In all the strontia; they will enter into the'different species of the Cinchona, kinic acid is found; parts of the plant, just as the coloured juice but the quantity of quinina, cinchonina, and mentioned above, and will be found in its lime, which they contain is most variable. ashes if it should be burnt at this period. From the fixed bases in the products of in- Their presence is merely accidental; but no cineration, however, we may estimate pretty conclusion can be hence deduced against accurately the quantity of the peculiar or- themnecessity of the presence of other bases ganic bases. A maximum of the first cor- in plants. The experiments of Macaireresponds to a minimum of the latter, as Princep have shown, that plants made to must necessarily be the case if they mutually vegetate with their roots in a weak solution replace one another according to their equi- of acetate of lead, and then in rain water, valents. We know that different kinds of opium contain meconic acid in combination * Robiquet did not obtain a trace of meconate with very different quantities of narcotina, of lime from 300 lbs. of opium, whilst in other roorphia, codeia, kc., the quantity of one kinds the quantity was very considerable. Ann. of these alkaloids diminishingon the increase de CBiot, in. iii. p. 425. rendus des et Biot, in the Comptes rendus des Seances de of the others. Thus the smallest quantity l'Academie des Sciences, a Paris, ler Semestre, of morphia is accompanied by a maximum 1837, p. 12. 40 AGRICULTURAL CHEMISTRY. yield to the latter all the salt of lead which of potash. The proportion of this salt does they had previously absorbed. They return, not vary perceptibly in the soil of corn-fields, therefore, to the soil all matters which are because it is again conveyed to them as maunnecessary to their existence. Again, when nure in the form of putrefying straw. But a plant, freely exposed to the atmosphere, this is not the case in a meadow, and hence rain, and sunshine, is sprinkled with a solu- we never find a luxuriant crop of grass' on tion of nitrate of strontia, the salt is ab- sandy and calcareous soils, which contain sorbed, but it is again separated by the roots little potash, evidently because one of the and removed farther from them by every constituents indispensable to the growth of shower of rain, which moistens the soil, so the plants is wanting. Soils formed from that at last not a trace of it is to be found in basalt, grauwacke, and porphyry are, cceteris the plant. paribus, the best for meadow land, on acLet us consider the composition of the count of the quantity of potash which enters ashes of two fir-trees as analysed by an acute into their composition. The potash aband most accurate chemist. One of these stracted by the plants is restored during the grew in Norway, on a soil the constituents annual irrigation. The potash contained in of which never changed, but to which solu- the soil itself is inexhaustible in comparison ble salts, and particularly common salt, were with the quantity removed by plants. But conveyed in great quantity by rain-water. when we increase the crop of grass in a How did it happen that its ashes contained meadow by means of gypsum, we remove no appreciable trace of salt, although we are a greater quantity of potash with the hay certain that its roots must have absorbed it than can under the same circumstances be after every shower? restored. Hence it happens that, after the We can explain the absence of salt in lapse of several years, the crops of grass on this case by means of the direct and positive the meadows manured with gypsum dimiobservations referred to, which have shown nish, owing to the deficiency of potash. But that plants have the power of returning to if the meadow be strewed from time to time the soil all substances unnecessary to their with wood-ashes, even with the lixiviated existence; and the conclusion to which all ashes which have been used by soap-boilers, the foregoing facts lead us, when their real (in Germany much soap is made from the value and bearing are apprehended, is that ashes of wood,) then the grass thrives as the alkaline bases existing in the ashes of luxuriantly as before. The ashes are only plants must be necessary to their growth, a means of restoring the potash. since if this wvere not the case they would A harvest of grain is obtained every thirty not be retained. or forty years from the soil of the Luneburg The perfect developement of a plant, ac- heath, by strewing it with the ashes of the cording to this view, is dependent on the heath plants (Erica vulgaris) which grow presence of alkalies or alkaline earths; for on it. These plants during the long perina when these substances are totally wanting just mentioned collect the potash and soca, its growth will be arrested, and when they which are conveyed to them by rain-water; are only deficient it must be impeded. and it is by means of these alkalies that oats, In order to apply these remarks, let us barley, and rye, to which they are indiscompare two kinds of trees, the wood of pensable, are enabled to grow on this sandy which contains unequal quantities of alka- heath. line bases, and we shall find that one of The woodcutters in the vicinity of Heidelthese grows luxuriantly in several soils upon berg have the privilege of cultivating the which the others are scarcely able to vege- soil for their own use, after felling the'trees tate. For example, 10,000 parts of oak used for making tan. Before sowing the wood yield 250 parts of ashes- the same land thus obtained, the branches, roots, and quantity of fir wood only 83, of linden wood leaves, are in every case burned, and the 500, of rye 440, and of the herb of the po- ashes used as a manure, which is found to tato plant 1500 parts." be quite indispensable for the growth of the Firs and pines find a sufficient quantity grain. The soil itself upon which the oats of alkalies in granitic and barren sandy soils grow in this district consists of sandstone; in which oaks will not grow; and wheat and although the trees find in it a quantity thrives in soils favourable for the linden of alkaline earths sufficient for their own tree, because the bases which are necessary sustenance, yet in its ordinary condition it is to bring it to complete maturity, exist there incapable of producing grain. in sufficient quantity. The accuracy of The most decisive proof of the use of strong these conclusions, so highly important to manure was obtained at Bingen (a town on agriculture and to the cultivation of forests, the Rhine,) where the produce and devecan be proved by the most evident facts. topement of vines were highly increased by All kinds of grasses, the Equisetacece, for example, contain in the outer parts of their * It would be of importance to examine what leaves and stalk a large quantity of silicic alkalies are contained in the ashes of the sea-shore acid and potash in the form of acid silicate plants which grow in the humid hollows of downs, and especially in those of the millet-grass. If potash is not found in them, it must certainly be * Berthier, Annales de Chimie et de Physique, replaced by soda as in the Salsola, or by lime as t. xxx. p. 248. in the Plumbaginee. CONSTITUENTS OF PLANTS. 41 manuring them with such substances as shav- The supposition of alkalies, metallic oxings of horn, &c.; but after some years the ides, or inorganic matter in general, being formation of the wood and leaves decreased produced by plants, is entirely refuted by to the great loss of the possessor, to such a these well-authenticated facts. degree that he has long had cause to regret It is thought very remarkable, that those his departure from the usual methods. By plants of the grass tribe, the seeds of which the manure employed by him, the vines had furnish food for man, follow him like the been too much hastened in their growth; in domestic animals. But saline plants seek two or three years they had exhausted the the sea-shore or saline springs, and the potash in the formation of their fruit, leaves, Chenopodium the dunghill from similar and wood, so that none remained for the fu- causes. Saline plants require common salt, ture crops, his manure not having contained and the plants which grow only on dungany potash. hills need ammonia and nitrates, and they There are vineyards on the Rhine the are attracted whither these can be found, plants of which are a hundred years old, just as the dung-fly is to animal excrements. and all of these have been cultivated by So likewise none of our corn-plants can manuring them with a cow-dung, a manure bear perfect seeds, that is, seeds yielding eontaining -a large proportion of potash, flour, without a large supply of phosphate although very little nitrogen. All the potash, of magnesia and ammonia, substances which in fact, which is contained in the food con- they require for their maturity. And hence, sumned by a cow is again immediately dis- these plants grow only in a soil where these charged in its excrements. three constituents are found combined, and The experience of a proprietor of land in no soil is richer in them than those where the vicinity of Gottingen offers a most re- men and animals dwell together; where the markable example of the incapability of a urine and, excrements of' these are found soil to produce wheat or grasses in general, corn-plants appear, because their seeds canwhen it fails in any one of the materials ne- not attain maturity unless supplied with the cessary to their growth. In order to obtain constituents of those matters. potash, he planted his whole land with When we find sea-plants near our saltwormwood, the ashes of which are well works, several hundred miles distant from known to contain a large proportion of the the sea, we know that their seeds have been carbonate of that alkali. The consequence carried there in a very natural manner, was, that he rendered his land quite incapa- namely, by wind or birds, which have ble of bearing grain for many years, in con- spread them over the whole surface of the sequence of having entirely deprived the earth, although they grow only in those soil of its potash. places in which they find the conditions The leaves and small branches of trees essential to their life. contain the most potash; and the quantity Numerous small fish, 6O not more than of them which is annually taken from a two inches in length (Gasterostets aculeatus,) wood for the purpose of being employed as are found in the salt-pans of the graduating litter,* contain more of that alkali than all house at Nidda (a village in Hesse Darmthe old wood which is cut down. The stadt.) No living animal is found in the bark and foliage of oaks, for example, con- salt-pans of Neuheim, situated about 18 tain from 6 to 9 per cent. of this alkali; the miles from Nidda; but the water there conneedles of firs and pines, 8 per cent. tains so much carbonic acid and lime, that With every 2650 lbs. of firwood which the walls of the graduating house are covered are yearly removed from an acre of forest, with stalactites. Hence the eggs conveyed only from 0'114 to 0'53 lbs. of alkalies are to this place by birds do not find the condiabstracted from the soil, calculating the tions necessary for their developement, ashes at 0'83 per cent. The moss, however, which they found in the former place.* which covers the ground, and of which the ashes are known to contain so much alkali, continues uninterrupted in its growth and * The itch-insect (Acarus Scabiei) is considered retainus that potash on the surgace, ahnh by Burdach as the production of a morbid condiretains that potash on the surface, which tion, so likewise lice in children; the original would otherwise so easily penetrate with,eneration of the fresh-water muscle (mytilus) in the rain through the sandy soil. By its de- Ash-ponds, of sea-plants in the vicinity of saltcav, an abundant provision of alkalies is works, of nettles and grasses, of fish in pools of supplied to the roots of the trees, and a fresh rain, of trout in mountain streams, &c., is ac. supply is rendered unnecessary. cording to the same natural philosopher not im. supply is renderedunnecessarypossible. A soil consisting of crumbled rocks, decayed vegetables, rain and salt water, &c., is here supposed to possess the power of generating [* This refers to a custom some time since shell-fish, trout, and saltwort (salicornia.) All very prevalent in Germany although now discon- inquiry is arrested by such opinions, when propa. tinued. The leaves and small twigs of trees gated by a teacher who enjoys a merited reputa. were gleaned from the forests by poor people, for tion, obtained by knowledge and hard labour. the purpose of being used as litter for their cattle. These subjects, however, have hitherto met The trees, however, were found to suffer so much with the most superficial observation, although in consequence, that their removal is strictly pro- they well merit strict investigation. The dark, hibited. The cause of the injury was that stated the secret, the mysterious, the enigmatic, is, in in the text.-ED.] fact, too seducing for the youthful and philosophio 6 D2 42 AGRICULTURAL CHEMISTRY. How much more wonderful and inexpli- plants in the direction of the wind are cable does it appear, that bodies which re- covered with crystals of salt, even at the mained fixed in the strong heatof a fire, have distance of from 20 to 30 miles from the under certain conditions the property of sea. But it does not require a storm to volatilizing and, at ordinary temperatures, cause the volatilization of the salt, for the of passing into a state, of which we cannot air hanging over the sea always contains say whether they have really assumed the enough of this substance to make a solution form of a gas or are dissolved in one! Steam of nitrate of silver turbid, and every breeze or vapours in general have a very singular must carry this away. Now, as thousands influence in causing the volatilization of of tons of sea water annually evaporate into such bodies, that is, of causing them to as- the atmosphere, a corresponding quantity sume the gaseous form. A liquid during of' the salts dissolved in it, viz. of' common evaporation communicates the power of as- salt, chloride of potassium, magnesia, and suming the same state in a greater or less the remaining constituents of the sea water, degree to all substances dissolved in it, will be conveyed by wind to the land. although they do not of themselves possess This volatilization is a source of conthat property. siderable loss in salt works, especially vWhere Boracic acid is a substance which is com- the proportion of salt in the water is not pletely fixed in the fire; it suffers no change large. This has been completely proved at of weight appreciable by the most delicate the salt works of Nauheim, by the very balance, when exposed to a white heat, and, intelligent director of that establishment, M. therefore, it is not volatile. Yet its solution Wilhelmi. He hung a plate of glass bein water cannot be evaporated by the gen- tween two evaporating houses, which were tlest heat, without the escape of a sensible about 1200 paces distant from each other, quantity of the acid with the steam. Hence and found in the morning, after the drying it: is that a loss is always experienced in the of the dew, that the glass was covered with analysis of minerals containing this acid, crystals of salt on one or the other side, acwhen liquids in which it is dissolved are cording to the direction of the wind. evaporated. The quantity of boracic acid By the continual evaporation of the sea, which escapes with a cubic foot of steam, its salts~ are spread over the whole surface at the temperature of boiling water, cannot of the earth; and being subsequently carbe detected by our most sensible re-agents; ried down by the rain, furnish to the vegetaand nevertheless the many hundred tons tion those salts necessary to its existence. annually brought from Italy as an article of This is the origin of the salts found in the commerce, are procured by the uninter- ashes of plants, in those cases where the rupted accumulation of this apparently in- soil could not have yielded them. appreciable quantity. The hot steam which In a comprehensive view of the pheissues from the interior of the earth is al- nomena of nature, we have no scale for lowed to pass through cold water in the that which we are accustomed to name, lagoons of Castel Nu.jova and Cherchiago; in small or great; all our ideas are proportioned this way the boracic acid is gradually accu- to what we see around us, but how insigrnulated, till at last it may be obtained in nificant are they in comparison with the crystals by the evaporation of the water. It whole mass of the globe! that which is is evident, from the temperature of the scarcely observable in a confined district steam, that it must have come out of depths appears inconceivably large when regarded in which human beings and animals never in its extension through unlimited space. could have lived, and yet it is very remarka- The atmosphere contains only a thousandth ble and highly important that ammonia is part of its weight of carbonic acid; and yet never absent from it. In the large works in small as this proportion appears, it is quite Liverpool, where natural boracic acid is converted into borax, many hundred pounds of sulphate of ammonia are obtained at the * According to Marcet, sea-water contains in same time. 1000 parts, This ammonia has not been produced by the 4660 Chloride of Sodium. animal organism, it existed before the creation 1'232 Chloride of Potassium. of humtlan beingos; it is a part, a pr*iary 5-152 Chloride of' Magnesium. constituent, of the globe itself. 0.153 Sulphate of Lime. The experiments instituted under Lavoi- According to M' Clemm, the water of the North sier's guidance by the Dir ection des Poudes Sea contains in o1000 parts, et Salpdtres, have proved that during the 2484 Chloride of Sodium. 2'42 Chloride of Magnesium. evaporation of the saltpetre ley, the salt 2'06 Sulphate of Magnesia. volatilizes with the water, and causes a loss 1'25 Chloride of Potassium. which could not before be explained. It is 1'20 Sulphate of Lime. known also, that in sea storms, leaves of In addition to these constituents, it also contains inappreciable quantities of carbonate of lime, magnesia, iron, manganese, phosphate of lime, mind, which would penetrate the deepest depths iodides and bromides, silica, sulphuretted hyof nature, without the assistance of the shaft or drogen, and organic matter, together with am. ladder of the miner. This is poetry, but not sober monia and carbonic acid. (Liebig's Annalen der philosophical inquiry. Chemie, Bd. xxxvii. s. 3.) T-HE ART OF CULTURE. 43 sufficient to supply the whole of the present preceding part of the work. Carbonic acid, generation of living beings with carbon for ammonia, and water yield elements for all a thousand years, even if it were not re- the organs of plants. Certain inorganic newed. Sea-water contains 12i — of its substances-salts and metallic oxides-serve weight of carbonate of lime; and this quan- peculiar functions in their organism, and tity, although scarcely appreciable in a many of them must be viewed as essential pound, is the source from which myriads constituents of particular parts. of marine mollusca and corals are supplied The atmosphere and the soil offer the same with materials for their habitations. kind of nourishment to the leaves and roots. Whilst the air contains only from, 4 to 6 The former contains a comparatively inexten-thousandth parts of its volume of car- haustible supply of carbonic acid and ambonic acid, sea-water contains 100 times monia; the latter, by means of its humus, more, (10,000 volumes of sea-water contain generates constantly fresh carbonic acid, 620 volumes of carbonic acid-Laurent, whilst, during the winter, rain and snow inBouillon, Lagrange.) Ammonia- is also troduce into the soil a quantity of ammonia, found in this water, so that the same condi- sufficient for the developement of the leaves tions which sustain living beings on the land and blossoms. are combined in this medium, in which a The complete, or it may be said, the absowhole world of other plants and animals lute insolubility in cold water of vegetable exist. matter in progress of decay, (humus,) apThe roots of plants are constantly en- pears on closer consideration to be a most gaged in collecting from the rain those wise arrangement of nature. For if humus alkalies which formed part of the sea-water, possessed even a smaller degree of solubility and also those of the water of springs, than that ascribed to the substance called huwhich penetrates the soil. Without alkalies imic acid, it must be dissolved by rain-water. and alkaline bases most plants could:not Thus, the yearly irrigation of meadows, exist, and without plants the alkalies would which last for several weeks, would remove disappear gradually from the surface of the a great part of it from- the ground, and a earth. heavy and continued rain would impoverish' When it is considered, that sea-water con- the soil. But it is soluble only when comtains less than one-millionth of its own bined with oxygen; it can be taken up by weight of iodine, and that all combinations water, therefore, only as carbonic acid. of iodine with the metallic bases of alkalies When kept in a dry place, humus may be are highly soluble in water, some provision preserved for centuries; but when moistmust necessarily be supposed to exist in the ened with water, it converts the surrounding organization of sea-weed and the different oxygen into carbonic acid. As soon as the kinds of Fuci, by which they are enabled action of the air ceases, that is, as soon as it is during their life to extract iodine in the deprived of oxygen, the humus suffers no farform of a soluble salt from sea-water, and ther change. Its decay proceeds only when to assimilate it in such a manner, that it is plants grow in the soil containing it; for not again restored to the surrounding me- they absorb by their roots the carbonic acid dium. These plants are collectors of iodine, as it is formed. The soil receives again from just as land plants are of alkalies; and they living plants the carbonaceous matter it thus yield us this element, in quantities such as loses, so that the proportion of humus in it we could not otherwise obtain from the does not decrease. water without the evaporation of whole The stalactitic caverns in Franconia, and seas. those in the vicinity of Baireuth, and StreitWe take it for granted that the sea-plants berg, lie beneath a fertile arable soil; the require metallic iodides for their growth, and abundant decaying vegetables or humus in that their existence is dependent on the this soil, being acted on by moisture and air, presence of those substances. With equal constantly evolve carbonic acid, which is disjustice, then, we conclude, that the alkalies solved by the rain. The rain-water thus and alkaline earths, always found in the impregnated permeates the porous limeashes of land-p'lants, are likewise necessary stone, which forms the walls and roofs of for their developement. the caverns, and dissolves in its passage as much carbonate of lime as corresponds to the quantity of carbonic acid contained in it. Water and the excess of carbonic acid evaCHAPTER VII. porate from this solution when it has reached the interior of the caverns, and the limestone THE ART OF CUIJTURE. is deposited on the walls and roofs in crystalline crusts of various forms. There are THE conditions necessary for the life of few spots on the earth where so many cirall vegetables have been considered in the cumstances favourable to the production of humate of lime are combined, if the humus * When the solidsaline residue obtained by the actually existed in the soil in the form of When the solidsaline residue obtained by the ic acid. Decaying veea- atr evaporation of sea-water is heated in a retort to hum acid. Decaying vegetable matter, redness, a sublimate of sal-ammoniac is obtained. water, and lime in sotntion, are brought to-M-RCrET. gether, but the stalactites formed contain no 44 AGRICULTURAL CH EMISTRY. trace of vegetable matter, and no humic oxygen; plants would be as little able to acid; they are of a glistening white or yel- grow in such ground as they would if hylowish colour, and in part transparent, like drated protoxide of iron were mixed with the calcareous spar, and may be heated to red- soil. Indeed some barren soils have been ness without becoming black. found to owe their fertility to this very cause The subterranean vaults in the old castles The sulphate of protoxide of iron (coppe near the Rhine, the " Bergstrass," and ras,) which forms a constituent of these soils, Wetherau, are constructed of sandstone, possesses a powerful affinity for oxygen, granite, or basalt, and present appearances and consequently prevents the absorption of similar to the limestone caverns. The roofs that gas by the roots of plants in its vicinity.of these vaults or cellars are covered exter- All plants die in soils and water which connally to the thickness of several feet with tain no oxygen; absence of air acts exactly vegetable mould, which has been formed by in the same manner as an excess of carbonic the decay of plants. The rain falling upon acid. Stagnant water on a marshy soil exthem sinks through the earth, and dissolves eludes air, but a renewal of water has the the mortar by means of the carbonic acid same effect as a renewal of air, because waderived from -the mould; and this solution ter contains it in solution. If the water is evaporating in the interior of the vaults, withdrawn from a marsh, free access is covers them with small thin stalactites, given to the air, and the marsh is changed which are quite free from humic acid. into a fruitful meadow. In such a filtering apparatus, built by the In a soil to which the air has no access, hand of nature, we have placed before us ex- or at most but very little, the remains of aniperiments which have been continued for a mals and vegetables do not decay, for they hundred or thousand years. Now, if water can only do so when freely supplied with possessed the power of dissolving a hun- oxygen; but they undergo putrefaction, for dredth thousandth part of its own weight of which air is present in sufficient quantity. humic acid or humate of lime, and humic Putrefaction is known to be a most powerfill acid were present, we should find the inner deoxidising process, the influence of which surface of the roofs of these vaults and cav- extends to all, surrounding bodies, even to erns covered with these substances; but we the roots and the plants themselves. All cannot detect the smallest trace of them. substances from which oxygen can be ex. There could scarcely be found a more clear tracted yield it to putrefying bodies; yellow and convincing proof of the absence of the oxide of iron passes into the state of black humic acid of chemists; in common vegeta- oxide, sulphate of iron into sulphuret of ble mould. iron, &c. The common view, which has been The frequent renewal of air by ploug'hing, adopted respecting the modus operandi of and the preparation of the soil, especially its humic acid, does not afford any explanation contact with alkaline metallic oxides, the of the following phenomenon:-A very ashes of brown coal, burnt lime or limestone, small quantity of humic acid dissolved in change the putrefaction of its organic conwater gives it a yellow or brown colour. stituents into a pure process of oxidation; Hence it would be supposed that -a soil and from the moment at which all the orwould be more fruitful in proportion as it ganic matter existing in a soil enters into a was capable of giving this colour to water, state of oxidation or decay, its fertility is inthat is, of yielding it humic acid. But it is creased. The oxygen is no longer employed very remarkable that plants do not thrive in for the conversion of the brown soluble matsuch a soil, and that all manure must have ter into the insoluble coal of humus, but lost this property before it can exercise a fa- serves for the formation of carbonic acid. vourable influence upon their vegetation. This change takes place very slowly, and in TVater from barren peat soils and marshy some instances the oxygen is completely exmeadows, upon which few plants flourish, cluded by it; and whenever this happens, contains much of this humic acid; but all the soil loses its fertility. Thus, in the agriculturists and gardeners agree that the vicinity of Salzhausen (a village in Hesse most suitable and best manure for plants is Darmstadt, famed for its mineral springs, that which has completely lost the property upon a meadow called Grinschwalheimer, of giving a colour to water. unfruitful spots are seen here and there The soluble substance, which gives to covered with a yellow grass. If a hole be water a brown colour, is the product of the bored from twenty to twenty-five feet deep putrefaction of all animal and vegetable in one of these spots, carbonic acid is emitmatter; its formation is an evidence that ted from it with such violence that the noise there is not oxygen sufficient to begin, or at made by the escape of the gas may be disleast to complete the decay. The brown solutions containing this substance are deco- * The most obvious method of removing this lourised in the air by absorbing oxygen, and salt from soils in which it may be contained is to a black coaly matter precipitates-the sub- manure the land with lime. The lime unites with stance named " coal of humus." Now if a the sulphuric acid and liberates the protoxide of soil were impregnated with this matter, the iron, which absorbs oxygen with much rapidity, soi wripeaewttimand is converted into the peroxide of iron. This effect on the roots of plants would be the conversion is accelerated by giving free access to same as that of entirely depriving the soil of the air, that is, by loosening the soin. THE ART OF CULTURE. 45 tnctly heard at the distance of several feet. the carbonic acid which the plants now abHere the carbonic acid rising to the surface sorb is employed for the production of nudisplaces completely all the air, and conse- tritive matter for the following year: instead quently all the oxygen, from the soil; and of woody fibre, starch is formed, and is difand without oxygen neither seeds nor roots fused through every part of the plant by the'an be developed; a plant will not vegetate autumnal sap.(sve d'Aofit.)5 According in pure nitrogen orlcarbonic acid gas. to the observations of M. Heyer, the starch Humus supplies young plants with nou- thus deposited in the body of the tree can be rishment by the roots, until their leaves are recognised in its known form by the aid of a matured sufficiently to act as exterior organs good microscope. The barks of several asof nutrition; its quantity heightens the fer- pens and pine-treest contain so much of this tility of a soil by yielding more nourishment substance, that it can be extracted from them in this first period of growth, and conse- as from potatoes by trituration with water. Ii quently by increasing the number of organs exists also in the roots and other parts of p:of atmospheric nutrition. Those plants rennialplants. Averyearly winter,orsuddei, which receive their first food from the sub- change of temperature, prevents the formastance of their seeds, such as bulbous plants, tion of this provision for the following year; could completely dispense with humus; its the wood, as in the case of the vine-stock, presence is useful only in so far as it in- does not ripen, and its growth is in the next creases and accelerates their developement, year very limited. but it is not necessary-indeed, an excess of From the starch thus accumulated, sugar it at the commencement of their growth is and gum are produced in the succeeding in a certain measure injurious. spring,while from the gum those constituThe amount of food which young plants ents of the leaves and young sprouts which can take from the atmosphere in the form of contain no nitrogen are in their turn formed. carbonic acid and ammonia is limited; they After potatoes have germinated, the quantity cannot assimilate more than the air contains. of starch in them is found diminished. The Now, if the quantity of their stems, leaves, juice of the maple-tree ceases to be sweet and branches has been increased by the ex- from the loss of its sugar when its buds, cess of food yielded by the soil at the com- blossoms, and leaves attain their maturity. mencement of their developement, they will The branch of a willow, which contains require for the completion of their growth, a large quantity of granules of starch in and for the formation of their blossoms and every part of its woody substance, puts forth fruits, more nourishment from the air than both roots and leaves in pure distilled rainit can afford, and consequently they will water; but in proportion as it grows, the not reach maturity. In many cases the starch disappears, it being evidently exnourishment afforded by the air under these hausted for the formation of the roots and circumstances suffices only to complete the leaves. In the course of these experiments, formation of the leaves, stems, and branches. M. Heyer made the interesting observation, The same result then ensues as when orna- that such branches when placed in snow mental plants are transplanted from the pots water (which contains ammonia) produced in which they have grown to larger ones, roots three or four times longer than those in which their roots are permitted to increase which they formed in pure distilled water, and multiply. All their nourishment is em- and that this pure water remained clear, ployed for the increase of their roots and while the rain-water gradually acquired a leaves; they spring, as it is said, into an yellow colour. herb or weed, but do not blossom. When, Upon the blossoming of the sugar-cane, on the contrary, we take away part of the likewise, part of the sugar disappears; and branches, and of course their leaves with it has been ascertained, that-the sugar does them, from dwarf trees, since we thus pre- not accumulate in the beet-root until after vent the developement of new branches, an the leaves are completely formed. excess of nutriment is artificially procured Much attention has recently been drawn for the trees, and is employed by them in to the fact that the produce of potatoes may the increase of the blossoms and enlargement be much increased by plucking off the blosof the fruit. It is to effect this purpose that soms from the plants producing them, a vines are pruned. result quite consistent with theory. This A new and peculiar process of vegetation important observation has been completely ensues in all perennial plants, such as confirmed by M. Zeller, the director of the shrubs, fruit and forest trees, after the com- Agricultural Society at Darmstadt. In the plete maturity of their fruit. The stem of year 1839, two fields of the same size, lying annual plants at this period of their growth side by side and manured in the same manbecomes woody, and their leaves change in ner, were planted with potatoes. When the colour. The leaves of trees and shrubs, on plants had flowered, the blossoms were rethe contrary, remain in activity until the com-,mencement of the winter. The formation of the layers of wood progresses, the wood * Hartig, in Erdmann und Schweigger.Seidels Journal, V. 217. 1835. becomes harder and more solid, but after t It is well known that bread is made from the August the leaves form no more wood; all bark of pines in Sweden during famines. 46 AGRICULTURAL CHEMISTRY. moved from those in one field, while those the leaves is to form starch, woody fibre,. in the other field were left untouched. The and sugar; consequently, if we convey these former produced 47 bolls, the latter only 37 substances through the roots, the vital funcbolls. tions of the leaves must cease, and if the These well-authenticated observations re- process of assimilation cannot take another move every doubt as to the part which sugar, form, the plant must die. starch, and gum play in the developement of Other substances must be present in a plants; and it ceases to be enigmatical, why plant, besides the starch, sugar and gum, if these three substances exercise no influence these are to take part in the developement on the growth or process of nutrition of a of the germ, leaves, and first radicle fibres. matured plant, when supplied to them as There is no doubt that a grain of wheat confood. tains within itself the component parts of The accumulation of starch in plants the germ and of the radicle fibres, and, we during the autumn has been compared, al- must suppose, exactly in the proportion nethough certainly erroneously, to the fatten- cessary for their formation. These compoingofhibernating animals before their winter nent parts are starch and gluten; and it is sleep; but in these animals every vital func- evident that neither of them alone, but that tion, except the process of respiration, is both simultaneously assist in the formation suspended, and they only require, like a of the root, for they both suffer changes lamp slowly burning, a substance rich in under the action of air, moisture, and a suitcarbon and hydrogen to support the pro- able temperature. The starch is converted cess of combustion in the lungs. On their into sugar, and the gluten also assumes a awaking from their torpor in the spring, the new form, and both acquire the capability, of fat has disappeared, but has not served as being dissolved in water, and of thus being nourishment. It has not caused the least conveyed to every part of the plant. Both increase in any part of their body, neither the starch and the gum are completely conhas it changed the quality of any of their sumed in the formation of the first part of organs. With nutrition, properly so called, the roots and leaves; and excess of' either the fat in these animals has not the least could not be used in the formation of leaves, connexion. or in any other way. The annual plants form and collect their The conversion of starch into sugar during future nourishment in the same way as the the germination of grain is ascribed to a perennial; they store it in their seeds in the vegetable principle called diastase, which is form of vegetable albumen, starch and gum, generated during the act of commencing which are used by the germs for the forma- germination. But this mode of transformation of their leaves and first radicle fibres. tion can also be effected by gluten, although The proper nutrition of the plants, their in- it requires a longer time. Seeds, which have crease in size, begins after these organs are germinated, always contain much more diasformed. tase than is necessary for the conversion of Every germ and every bud of a perennial theirstarch into sugar, forfive-parts byweight plant is the engrafted embryo of a new indi- of starch can be converted into sugar by one vidual, while the nutriment accumulated in partof malted barley. This excess of diastase the stem and roots, corresponds to the albu- can by no means be regarded as accidental, men of the seeds.; for, like the starch, it aids in the formation Nutritive matters are, correctly speaking, of the first organs of the young plant, and those substances which, when presented disappears with the sugar; diastase contains from without, are capable of sustaining the nitrogen and furnishes the elements of velife and all the functions of an organism, by getable albumen. furnishing to the different parts of plants the Carbonic acid, water, and ammonia, are materials for the production of their peculiar the food of fully-developed plants; starch, constituents. sugar, and gum, serve, when accompanied In animals, the blood is the source of the by an azotised substance, to sustain the emmaterial of the muscles and nerves; by one bryo, until its first organs of nutrition are of its component parts, the blood supports unfolded. The nutrition of a foetus and dethe process of respiration, by others, the velopement of an egg proceed in a totally peculiar vital functions; every part of the different manner from that* of an animal body is supplied with nourishment by it, which is separated from its parent; the exbut its own production is a special function, elusion of air does, not endanger the life of without which we could not conceive life the foetus, but would certainly cause the to continue. If we destroy the activity of death of the independent animal. In the the organs which produce it, or if we inject same manner, pure water is more advanthe blood of one animal into the veins of tageous to the growth of a young plant, another, at all events, if we carry this be- than that containing carbonic acid, but after yond certain limits, death is the consequence. a month the reverse is the case. If we could introduce into a tree woody The formation of sugar in maple-trees fibre in a state of solution, it would be the does not take place in the roots, but in the same thing as placing a potato plant to woody substance of the stem. The quantity vegetate in a paste of starch. The office of of sugar in the sap augments until it reaches THE ART OF CULTURE. 47 a certain height in the stem of the plant, the bark, roots, leaves, and branches. The above which point it remains stationary. exudations of mannite, gum, and sugar, in Just as germinating barley produces a strong and healthy plants cannot be ascribed substance which, in contact with starch, to any other cause.i causes it to lose its insolubility and to be- Analogous phenomena are presented by come sugar, so in the roots of the maple, at the — process of digestion in the human orthe commencement of vegetation, a sub- ganism. In order that-the loss which every stance must be formed, which, being dis- part of the body sustains by the processes solved in water, permeates the wood of the of respiration and perspiration'may be retrunk, and converts into sugar the starch, or stored to it, the organs of digestion require whatever it may be, which it finds deposited to be supplied with food, consisting of subthere. It is certain, that when a hole is stances containing nitrogen, and of' others bored into the trunk of a maple-tree just destitute of it, in definite proportions. If above its roots, filled with sugar, and then the substances which do not contain nitrogen closed again, the sugar is dissolved by the preponderate, either they will be expended ascending sap. It is further possible that in the formation of fat, or they will pass this sugar may be disposed of in the same unchanged through the organism. This is manner as that formed in the trunks; at all particularly observed in those people who events it is certain, that the introduction of live almost exclusively upon potatoes; their it does not prevent the action of the juice excrements contain a large quantity of un — upon the starch, and since the quantity of changed granules of starch, of which no the. sugar present is now greater than can trace can be detected when gluten or fleshbe exhausted by the leaves and buds, it is is taken in proper proportions, because in excreted from the surface of the leaves or this case the starch has been rendered capabark. -Certain diseases of trees, for example ble of assimilation. Potatoes, which when that called honey-dew, evidently depend on mixed with hay alone are scarcely capable the want of the due proportion between the of supporting the strength of a horse, form quantity of the azotised and that of the un- with'bread and oats a strong and wholesome: azotised substances which are applied to fodder. them as nutriment. It will be evident from the preceding conIn whatever form, therefore, we supply siderations, that the products generated- by plants with those substances which are the a plant may vary exceedingly, according to products of their own action, in no instance the substances given it as food. A superdo they appear to have any effect upon their abundance of carbon in the state of carbonic growth, or to replace what they have lost. acid conveyed through the roots of plants, Sugar, gum, and starch,'are not food for without being accompanied by nitrogen, plants, and the same must be said of humic cannot be converted either into gluten, alacid, which is so closely allied to them in bumen, wood, or any other'component part composition. of ani organ; but either it will be separated If'now we direct our attention to the par- in the form of excrements, such as sugar, tictular organs of a plant, we find every fibre starch, oil, wax, resin, mannite, or gum, or and every particle of wood surrounded by a these'substances will be deposited in greater juice containing an azotised matter; while or less quantity in the wide cells and vessels. the starch, granules, and sugar are enclosed The quantity of gluten, vegetable albuin cells formed of a substance containing ni- men, and mucilage, will augment when trogen. Indeed every where, in all the juices plants are supplied with an excess of food of the fruits and blossoms, we find a sub- containing nitrogen; and ammoniacal salts stance destitute of nitrogen,' accompanied will remain in the sap, when, for example, by one which contains that element. in the culture of the beet, we manure the The wood of the stem cannot be formed, soil with a highly nitrogenous substance, or qtasi wood, in: the leaves, but another sub- when we suppress the functions of the leaves stance must be produced which is capable by removing them from the plant. of being transformed into wood. This sub- We know that the ananas is scarcely stance must be in a state of solution, and eatable in its wild state, and that it shoots accompanied by a compound containing ni- forth a great quantity of leaves when treated trogen;' it is very probable that the wood with rich animal manure, without the fruit and the vegetable gluten, the starch granules on that account acquiring a large amount and the cells containing them, are formed of sugar; that the quantity of starch in posimultaneously, and in this case a certain tatoes increases when the soil contains much fixed'proportion between them would be a humus, but decreases when the soil is macondition necessary for their production. According to this view, the assimilation * M. Trapp, in Giessen, possesses a Clerodenof the substances generated in the leaves dronfragrans, which grows in the house, and exwill (cceteris paribus) depend on the quan- udes on the surface of its leaves in September tity of nitrogen contained in the food. When large colourless drops of sugar-candy, which form a sufficient quantity of nitrogen is not pre- regular crystals upon drying; —I am not aware sent to aid in the assimilation of the sub- whether the juice of this plant contains sugar. s Professor Redtenbacher, of Prague, informs me stances which do not contain it, these sub- that he has analysed the crystals, and found them stances will be separated as excrements from to be perfectly pure sugar.-ED. 48 AGRICULTURAL CHEMISTRY. nured with strong animal manure, although products only are observed (muriatic acid then the number of cells increases, the po- and perchloride of carbon); whilst by the tatoes acquiring in the first case a mealy, in latter method a class of intermediate bodies the second a soapy, consistence. Beet-roots, -are produced, in which the quantity of chlotaken from a barren, sandy soil, contain a rine constantly augments, until at last the maximum of sugar, and no ammoniacal whole liquid hydrocarburet of chlorine is salts; and the Teltowa parsnep loses its converted into the same two products as in mealy state in a manured land, because there the first case. Here, also, not the slightest all the circumstances necessary for the for- trace of decomposition takes place in the mation of cells are united.5 dark. Nitric acid is decomposed in commbn An abnormal production of certain com- daylight into oxygen, and peroxide-of nitroponent parts of plants presupposes a power gen; and chloride of silver becomes black. and capability of assimilation to which the in the diffused light of day, as well as in the most powerful chemical action cannot be direct solar rays; —in short, all actions of a compared. The best idea of it may be similar kind proceed in the same way in difformed by considering that it surpasses in fused light as well as in the solar light, the power the strongest galvanic battery, with only difference consisting in the time in which we are not able to separate the oxy- which they are effected. It cannot be othergen from carbonic acid. The affinity of wise in plants, for the mode of their nutrichlorine for hydrogen, and its power to de- ment is the same in all, and their component compose water under the influence of light substances afford proof that their food has and set at liberty its oxygen, cannot be con- suffered absolutely the same change, whether sidered as at all equalling the power and they grow in the sunshine or in the shade. energy with which a leaf separated from a All the carbonic acid, therefore, which plant decomposes the carbonic acid which we supply to a plant will undergo a transit absorbs. formation, provided -its quantity be not The common opinion, that only the direct greater than can be decomposed by the solar rays can effect the decomposition of leaves. We know that an excess of carcarbonic acid in the leaves of plants, and bonic acid kills plants, but we know also that reflected or diffused light does not pos- that nitrogen to a certain degree is not essensess this property, is wholly an error, for tial for the decomposition of carbonic acid. exactly the same constituents are generated All the experiments hitherto instituted prove, in a number of plants, whether the direct that fresh leaves placed in water impregnated rays of the sun fall upon them, or whether with carbonic acid, and exposed to the inthey grow in the shade. They require light, fluence of solar light, emit oxygen gas, and indeed sun-light, but it is not necessary whilst the carbonic acid disappears. Now that the direct rays of the sun reach them. in these experiments no nitrogen, is supplied Their functions certainly proceed with at the same time with the carbonic acid; greater intensity and rapidity in sunshine hence no other conclusion can be drawn than in the diffused light of day; but there from them than that nitrogen is not necesis nothing more in this than the similar sary for the decomposition of carbonic acid, action which light exercises on ordinary -for the exercise, therefore, of one of the chemical combinations; it merely accelerates functions of plants. And yet the presence in a greater or less degree the action already of a substance containing this element apsubsisting. pears to be indispensable for the assimilation Thus chlorine and hydrogen combining of the products newly formed by the decomform muriatic acid. This combination is position of the carbonic acid, and their coneffected in a few hours in common daylight, sequent adaptation for entering into the but it ensues instantly, with a violent ex- composition of the different organs. plosion, under exposure to the direct solar The carbon abstracted from the carbonic rays, whilst not the slightest change in the acid acquires in the leaves a new form, in two gases takes place in perfect darkness. which it is soluble and transferable to all When the liquid hydrocarburet of chlorine, parts of the plant. In this new form the resulting from the union of the olefiant gas carbon aids in constituting several new proof the associated Dutch chemists with chlo- ducts; these are named sugar when they rine, is exposed in a vessel with chlorine possess a sweet taste, gum or mucilage gas to the direct solar rays, chloride of car- when tasteless, and excrementitious matters bon is immediately produced; but the same when expelled by the roots. compound can be, obtained with equal faci- Hence it is evident that the quantity and lity in the diffused light of day, a longer time quality of the substances generated by the only being required. When this experiment vital processes of a plant will vary accordis performed in the way first mentioned, two ing to the proportion of the different kinds of food with which it is supplied. The de* Children fed upon arrow-root, salep, or in- velopement of every part of a plant in a deed any kind of amylaceous food, which does free and uncultivated state depends on the not contain ingredients fited for the formation of amount and nature of the food afforded to it bones and muscles, become fat, and acquire much by the spot on which it grows. A plant is embonpoint; their limbs appear full, but they do by the spot on which it grows. A plant is -not acquire strength, nor are their organs pro- developed on the most sterile and unfruitful perly developed. soil as well as on the most luxuriant and THE ART OF CULTURE. 49 fertile, the only difference which can be ob- Until these points are satisfactorily deterserved being in its height and size, in the mined, a rational system of agriculture cannumber of its twigs, branches, leaves, blos- not exist. The power and knowledge of the. soms, and fruit. Whilst the individual or- physiologist, of the agriculturist and chemist, gans of a plant increase on a fertile soil, must be united for the complete solution of they diminish on another where those sub- these questions; and in order to attain this stances which are necessary for their forma- end, a commencement must be made. tlon are not so bountifully supplied; and The general object of agriculture is to the proportion of the constituents which produce in the most advantageous manner contain nitrogen and of those which do not certain qualities, or a maximum size, in in plants varies with the amount of nitro- certain parts or organs of particular plantsgenous matters in their food. Now, this object can be attained only by the The developement of the stem, leaves, application of those substances which we blossoms, and fruit of plants is-dependent on know to be indispensable to the developement certain conditions, the knowledge of which of these parts or organs, or by supplying the enables us to exercise some influence on conditions necessary to the production of the their internal constituents as well as on their qualities desired. size. It is the duty of the natural philoso- The rules of a rational system of agriculpher to discover what these conditions are; ture should enable us, therefore, to give to for the fundamental principles of agriculture each plant that which it requires for the atmust be based on a knowledge of them. tainment of the object in view. There is no profession which can be com- The special object of agriculture is to obpared in importance with that of agricul- tain an abnormal developement and producture, for to it belongs the production of food tion of Certain parts of plants, or of certain for man and animals; on it depends the vegetable matters, which are employed as welfare and developement of the whole food for man and animals, or for the purhuman species, the riches of states, and all pose of industry. commerce. There is no other profession in -The means employed for effecting these which the application of correct principles two purposes are very different. Thus the is productive of more beneficial effects, or is mode of culture, employed for the purpose of greater and more decided influence. of procuring fine pliable straw for FlorenHence it appears quite unaccountable, that tine hats, is the very opposite to that which we may vainly search for one leading prin- must be adopted in order to produce a maxiciple in the writings of agriculturists and mum of corn from the same plant. Peculiar vegetable physiologists. methods must be used for the production ot The methods employed in the cultivation nitrogen in the seeds, others for giving of land are different in every country, and strength and solidity to the straw, and others in every district; and when we inquire the again must be followed when we wish to causes of these differences, we receive the give such strength and solidity to the straw answer, that they depend upon circum- as will enable it to bear the weight of the stances. (Les circonstances font les assole- ears. ments.) No answer could show ignorance We must proceed in the culture of plants more plainly, since no one has ever yet de- in precisely the same manner as we do in voted himself to ascertain what these cir- the fattening of animals. The flesh of the cumstances are. Thus also when we inquire stag and roe, or of wild animals in general, in what manner manure acts, we are an- is quite devoid of fat, like the muscular flesh swered by the most intelligent men, that its of the Arab; or it contains only small quanaction is covered by the veil of Isis-; and tities of it. The production of flesh and fat when we demand further what this means, may be artificially increased; all domestic we discover merely that the excrements of animals, for example, contain much fat. men and animals are supposed to contain We give food to animals, which increases an incomprehensible something which assists the activity of certain organs, and is itself in the nutrition of plants, and increases their capable of being transformed into fat. We size. This opinion is embraced without add to the quantity of food, or we lessen the even an attempt being made to discover the processes of respiration and perspiration by component parts of manure, or to become preventing motion. The conditions necesacquainted with its nature. sary to effect this purpose in birds are difIn addition to the general conditions, such ferent from those in quadrupeds; and it is as heat, light, moisture, and the component well known that charcoal powder produces parts of the atmosphere, which are neces- such an excessive growth of the liver of a sary for the growth of all plants, certain goose, as at length causes the death of the substances are found to exercise a peculiar animal. influence on the developement of particular The' increase or diminution of the vital families. These substances either are al- activity of vegetables depends only on heat ready contained in the soil, or are supplied and solar light, which we have not arbitrato it in the form of the matters known under rily at our disposal: all that we can do is to the general name of manure. But what supply those substances which are adapted does the soil contain, and what are the corn- for assimilation by the power already pro ponents of the substances used as manure? sent in the organs of the plant. But what 7E 50 AGRICULTURAL CHEMISTRY. then are these substances? They may inm most places entered the plants by means easily be detected by the examination of a of alkalies. In order to form a distinct consoil, which-is always fertile in given cosmi- ception of the quantities of alkalies in alucal and atmospheric conditions; for it is minous minerals, it must be remembered evident, that the knowledge of its state and that felspar contains 173 per cent. of potash, composition must enable us to discover the albite 11-43 per cent. of soda, and mica 3-5 circumstances under which a sterile soil per cent.; and that zeolite contains 13-16 may be rendered fertile. It is the duty of per cent. of both alkalies taken together. the chemist to explain the composition of a The late analyses of Ch. Gmelin, Lowe, fertile soil, but the discovery of its proper Fricke, Meyer, and Redtenbacher, have also state or condition belongs to the agricultu- shown, that basalt contains from: to 3 per rist; our present business lies only with the cent. of potash, and from 5-7 per cent. of former. soda, that clay slate contains from 2'75-3-31 Arable land is originally formed by the per cent. of potash, and loam froml —4 per crumbling of rocks, and its properties de- cent. of potash. pend on the nature of their principal com- If, now, we calculate from these data, and ponent parts. Sand, clay, and lime, are the from the specific weights of the different names given to the principal constituents of substances, how much potash must be conthe different kinds of soil. tained in a layer of soil, which has been Pure sand and pure limestones, in which formed by the disintegration of 26,910 square there are no other inorganic substances ex- feet (1 Hessian acre) of one of these rocks cept siliceous earth, carbonate or silicate of to the depth of 20 inches, we find that a lime, form absolutely barren soils. But ar- soil of gillaceous earths form always a part of fertile soils. Now from whence come the Clink-stone " from 220,000 to 440,000 argillaceous earths in arable land, what are Basalt "." 52,300 " 82,600 their constituents, and what part do they Clay-slate ".110,000 " 220,000" play in favouring vegetation? They are Loam, " " 95,000 " 330,000" produced by the disintegration of aluminous minerals by the action of the weather; the Potash is present in all clays; according to common potash and soda felspars, Labrador Fuchs it is contained even in marl; it has on spar, micaotas and sodathe zeoltespars, are the most ador been found in all the argillaceous earths in parcmmon auminou s e are ths, most which it has been sought. The fact that common a-luminous earths, which undergo they contain potash this change. These minerals are found they contain potash may be proved in the mixed with other substances ingranite, clays of the transition and stratified moungneiss, ica-slate, porphyry, clay-slanite, tains, as well as in the recent formations gneiss, mica-slate, porphyry,- clay-slate, surrounding Berlin, by simply digesting grauwacke, and the volcanic rocks, basalt, them ith surrounding Berlin, by simply digesting clinkstone, and lava. In the grauwacke, the withsulphuricacid,bywhichprocess we have pure quartz, clay-slate, and lime, alum is formed. (Mitscherlich.) It is well in the sandstones, quartz and loam. The known also toallmanufacturers of alum, transition limestone and the dolomites con- that the leys contain a certain quantity of tain an intermixture of clay, felspar, p- this salt ready formed, the potash of which p hyry, and clay-slate; and the mountain has its origin from the ashes of the stone limestone is remarkable for the quantity of and brown coal, which contain much argillaceous earth. argillaceous earths which it contains. Jura earth. aroillaceous earths which it contains. Jura When'we consider this extraordinary dislimestone contains 3-20, that of the Wur- When oe consider this extraordinary distemberg Alps 45-50 per cent. of these tribution of potash over the surface of the earths. And in the muschelkalk and the earth, is it reasonable to have recourse to calcaire grossier they exist in greater or less the idea, that the presence of this alkali in quantity. plants is due to the generation of a metallic quantity. It is known, that the aluminous minerals oxide by a peculiar organic process from the are the most widely diffused on the surface component parts of the atmosphere? This of the earth, and as we have already men- opinion found adherents even after the tioned, all fertile soils, or soils capable of method of detecting potash in soils was culture, contain alumina as an invariable known, and suppositions of the same kind constituent. There must, therefore, be may be found even in the writings of some something in aluminous earth which ena- physiologists of the present day. Such bles it to exercise an influence on the life of opinions belong properly to the time when plants, and to assist in their developement. flint was conceived to be a product of chalk, The property'on which this depends is that and when every thing which appeared inof its invariably containing potash and soda comprehensible on account of not having Alumina exercises only an indirect influ been investigated, was explained by assumpence on vegetation, by its power of attract-ons far more incomprehensible. ing and retaining water and ammonia; it is itself very rarely found in the ashes of very frequently stated in the results of their plants,* but silica is always present, having analyses; but in most cases it has been mistaken for phosphate of magnesia, or phosphate of alu. mina, with which it has many properties in com. * Alumina is generally supposed to be a com- mon, and from which it cannot be distinguished anon ingredient of the ashes of plants, and it is without much care and attention.-ED. THE ART OF CULTURE. 51 A thousandth part of loam mixed with faction, the soil receives again that which the quartz in new red sandstone, or with had been extracted from it. the lime in the different limestone forma- Let us suppose that a soil has been formed tions, affords as much potash to a soil only by the action of the weather on the compotwenty inches in depth as is sufficient to nent parts of granite, grauwacke, mountain supply a forest of pines growing upon it limestone, or porphyry, and that nothing has for a century. A single cubic foot of felspar vegetated on it for thousands of years. is sufficient to supply a wood, covering a Now this soil would become a magazine of surface of 26,910 square feet, with the alkalies in a condition favourable for their potash required for five years. assimilation by the roots of plants. Land of the greatest fertility contains The interesting experiments of Struve argillaceous earths and other disintegrated have proved that water impregnated with minerals with chalk and sand in such a pro- carbonic acid decomposes rocks which conportion as to give free access to air and tain alkalies, and then dissolves a part of moisture. The land in the vicinity of Vesu- the alkaline carbonates. It is evident that vius may be considered as the type of a fer- plants also, by producing carbonic acid tile soil, and its fertility is greater or less in during their decay, and by means of the different parts, according to the proportion acids which exude from their roots in the of clay or sand which it contains. living state, contribute no less powerfully to The soil which is formed by the disinte- destroy the coherence of rocks. Next to the gration of lava, cannot possibly, on account action of air, water, and change of temperaof its origin, contain the smallest trace of' ture, plants themselves are the most powervegetable matter, and yet it is well known ful agents in effecting the disintegration of that when the volcanic ashes have been ex- rocks. posed for some time to the influence of air Air, water, and the change of temperature and moisture, a soil is gradually formed in prepare the different species of rocks for which all kinds of plants grow with the yielding to plants the alkalies which they greatest luxuriance. This fertility is owing contain. A soil which has been exposed to the alkalies which. are contained in the for centuries to all the influences which lava, and which by exposure to the weather affect the disintegration of rocks, but from are rendered capable of being absorbed by which the alkalies have not been removed, plants. Thousands of years have been ne- will be able to afford the means of nourishcessary to convert stones and rocks into the ment to those vegetables which require soil of arable land, and thousands of years alkalies for its growth during many years' more will be requisite for their perfect re- but it must gradually become exhausted, duction, that is, fobr the complete exhaustion unless those alkalies which have been reof their alkalies. moved are again replaced; a period, thereWe see from the composition of the water fore, will arrive when it will be necessary in rivers, streamlets, and springs, how little to expose it from time to time to a farther rain-water is able to extract alkali from a disintegration, in order to obtain a new supsoil, even after a term of years; this water -ply of soluble alkalies. For small as is the is generally soft, and the common salt, quantity of alkali which plants require, it is which even the softest invariably contains, nevertheless quite indispensable for their proves that those alkaline salts, which are perfect developement. But when one or carried to the sea by rivers and streams, more years have elapsed without any alkaare returned again to the land by wind and lies having been extracted from the soil, a rain. new harvest may be expected. Nature itself shows us what plants re- The first colonists of Virginia found a quire at the commencement of the develope- country the soil of which was similar to that ment of their germs and first radicle fibres. mentioned above; harvests of wheat and Bequerel has shown that the graminac, tobacco were obtained for a century from leumninosce, cruciferc3, cichoracece, ummbelli- one and the same field, without the aid of ferce, coni;fece, and cucurbitacece emit acetic manure; but now whole districts are conacid during germination. A plant which verted into unfruitful pasture-land, which has just broken through the soil, and a leaf without manure produces neither wheat nor just burst open from the bud, furnish ashes tobacco. From every acre of this land there by incineration, which contain as much, were removed in the space of one hundred and generally more, of alkaline salts than years 12,000 lbs. of alkalies in leaves, grain, at any period of their life. (De Saussure.) and straw; it became unfruitful, therefore, Now we know also, from the experiments because it was deprived of every particle of of Bequerel, in what manner these alkaline alkali, which had been reduced to a soluble salts enter'young plants; the acetic acid state, and because that which was rendered formed during germination is diffused soluble again in the space of one year was through the wet or. moist soil, becomes not sufficient to satisfy the demands of the saturated with lime, magnesia, and alkalies, plants. Almost all the cultivated land in and is again absorbed by the radicle fibres Europe is in this condition; fallow is the in the form of neutral salts. After the ces- term applied to land left at rest for farther sation of life, when plants are subjected to disintegration. It is the greatest possible decomposition by mr.as of decay and putre- mistake to suppose that the temporary dimi 52 AGRICULTURAL CHEMISTRY. nution of fertility in a soil is owing to the soils do not contain alkalies in sufficient loss of humus; it is the mere consequence quantity, the growth of wheat being arreste4 of the exhaustion of the alkalies. by this circumstance, even should all other Let us consider the condition of the coun- substances be presented in abundance. try around Naples, which is famed for its It is not mere accident that only trees of fruitful corn-land; the farms and villages the fir tribe grow on the sandstone and limeare situated friom eighteen to twenty-four stone of' the Carpathian mountains and the miles distant from one another, and between Jura, whilst we find on soils of gneiss, micathem there are no roads, and consequently slate, and granite in Bavaria, of clinkstone no transportation of manure. Now corn on the Rhone, of basalt in Vogelsberge, and has been cultivated on this land for thousands of clay-slate on the Rhine and Eifel, the of years, without any part of that which is finest forests of other trees, which cannot be annually removed from the soil being artifi- produced on the sandy or calcareous soils cially restored to it. How can any influ- upon which pines thrive. It is explained ence be ascribed to humus under such cir- by the fact that trees, the-leaves of which cumstances, when it is not even known are renewed annually, require for their whether humus was ever contained in the leaves six to ten times more alkalies than the soil? fir-tree or pine, and hence when they are The method of culture in that district placed in soils in which alktalies are concompletely explains the permanent fertility. tained in: very small quantity, do not attain It appears very bad in the eyes of- our agri- maturity.* When we see such trees growculturists, but there it is the best plan which ing on a sandy or calcareous soil-the redcould be adopted. A field is cultivated once beech, the service-tree, and the wild-cherry every three years, and is in the intervals for example, thriving luxuriantly on lime. allowed to serve as a sparing pasture for stone, we may be assured that alkalies are cattle. The soil experiences no change in present in the soil, for they are necessary to the two years during which it there lies fal- their existence. Can we, then, regard it as low, farther than that it is exposed to the remarkable that such trees should thrive in influence of the weather, by which a fresh America, on those spots on which forests portion of the alkalies contained in it are of pines which have grown and collected again set free or rendered soluble. The ani- alkalies for centuries, have been burnt, and mals fed on these fields yield nothing to to which the alkalies are thus at once rethese soils which they did not formerly pos- stored; or that the Spartiunm scoparium, sess. The weeds upon which they live Erysimmn iatifolizun, Blitumn capitaturn, Sespring from the soil, and that which they necio viscosus, plants remarkable for the return to it as excrement must always be less quantity of alkalies contained in their ashes, than that which they extract. The fields, should grow with the greatest luxuriance on therefore, can have gained nothing from the the localities of conflagrations?t mere feeding of cattle upon them; on the Wheat will not grow on a soil which has contrary, the soil must have lost some of its produced wormwood, and vice versad, wormconstituents., wood does not thrive where wheat has Experience has shown in agriculture grown, because they are mutually prejuthat wheat should not be cultivated after dicial by appropriating the alkalies of the wheat on the same soil, for it belongs with soil. tobacco to the plants which exhaust a soil. One hundred parts of the stalks of wheat But if the humus of a soil gives it the power yield 15'5 parts of ashes (H. Davy;) the of producing corn, how happens it that same quantity of the dry stalks of barley, wheat does not thrive in many parts of Brazil, where the soils are particularly rich in this substance, or in our own climate, in rent kinds of limestone belonging to the secondary soiltis formed of wood;th at I it and tertiary fbrmations. ile obtained the remarksoils formed of mouldered wood; that its able result, that all those limestones, by the disstalk under these circumstances attains no integration of which soils adapted for the culture strength, and droops prematurely? The of wheat are formed, invariably contain a certain cause is this, that the strength of the stalk is quantity of potash. The same observation has due to silicate of potash, and that the corn also recently been made by M. Kuhlman of Lille. requires phosphate of magnesia, neither of The latter observed that the efflorescence on the requires phosphate of magnesia, neither of.mortar of warls consists of the carbonates of soda which substances a soil ofhumus canafford, and potash. since it does not contain them; the plant * One thousand parts of the dry leaves of oaks may, indeed, under such circumstances, be- yielded 55 parts of ashes, of which 24 parts concome an herb, but will not bear fruit. sisted of alkalies soluble in water; the same Again, ho(w does it happen that wheat quantity of pine-leaves gave only 29 parts of ashes, which contain 4.6 parts of soluble salts. (De dtoes not flourish on a sandy soil, and that a Saussure.) calcareous soil is also unsuitable for its 1 After the great fire in London, large quantigrowth, unless it be mixed with a consider- ties of the Eryszmum latifolitum where observed able quantity of clay?$ It is because these growing on the spots where a fire had taken place. On a similar occasion the Blitum capitatum was seen at Copenhagen, the Senecio viscosus in Nas. $ In consequence of these remarks in the former sau, and the Spartium scoparium in Languedoc. edition of this work, Professor Wihler of Gittin. After the burnings of forests of pines in North gen has made several accurate analyses of diffe- America,-poplars grew on the same soil. THE ART OF CULTURE. 53 8-54 parts (Schrader;) and one hundred also in all mineral waters in which its preparts of the stalks of oats, only 4-42;-the sence has been tested; and in those in ashes of all these are of the same compo- which it has not been found it has not been sition. sought for. The most superficial strata of We have in these facts a clear proof' of the deposits of sulphuret of lead (galena) what plants require for their growth. Upon contain crystallised phosphate of lead (greenthe same field, which will yield only one lead ore;) clay-slate, which forms extensive harvest of wheat, two crops of barley and strata, is covered in many places with crvsthree of oats may be raised. tals of phosphate of alumina (Wavellite';) All plants of the grass kind require sili- all its fractured surfaces are overlaid with it. cate of' potash. Now this is conveyed to Phosphate of lime (.Apatite) is found even the soil, or rendered soluble in it by the irri- in the volcanic boulders on the Laacher gation of meadows. The equiselacece,. the See in the Eifel, near Andernach." reeds and species of cane, for example, The soil in which plants grow furnishes which contain such large quantities of sili- them with phosphoric acid, and they in turn ceous earth, or silicate of potash, thrive yield it to animals, to be used in the formaluxuriantly in marshes, in argillaceous soils, tion of their bones, and of those constituents and in ditches, streamlets, and other places of the brain which contain phosphorus. where the change of water renews con- Much more phosphorus is thus afforded to stantly the supply of dissolved silica. The the body than it requires, when flesh, bread, amount of silicate of potash removed from fruit, and husks of grain are used for food, a meadow in the form of hay is very con- and this excess is eliminated in the urine siderable. We need only call to mind the and the solid excrements. We may form melted vitreous mass found on a meadow an idea of the quantity of phosphate of between Manheim and Heidelberg after a magnesia contained in grain, when we conthunder-storm. This mass was at first sup- sider that the concretions in the cemcum of posed to be a meteor, but was found on ex- horses consist of phosphate of magnesia amination (by Gmelin) to consist of silicate and ammonia, which must have been ohof potash; a flash of lightning had struck a tained from the hay and oats consumed as stack of'hay, and nothing was found in its food. Twenty-nine of these stones were place except the melted ashes of the hay. talien after death from the rectum of a horse Potash is not the only substance necessary belonging to a miller, in Eberstadt, the total for the existence of most plants; indeed it weight of which amounted to 3 lbs.; and has been already shown that the potash may Dr. F. Simon has lately described a similar be replaced in many cases by soda, magne- concretion found in the horse of a carrier, sia, or lime; but other substances'besides which weighed 1 lb. alkalies are required to sustain the life of It is evident that the seeds of corn could plants. not be formed without phosphate of magnePhosphoric acid has been found in the sia, which is one of their invariable conashes of all plants hitherto examined, and stituents; the plant could not under such always in combination with alkalies or alka- circumstances reach maturity. line earths.* Most seeds contain certain Some plants, however, extract other matquantities of phosphates. In the seeds of ters from the soil, besides silica, potash, and different kinds of corn particularly, there is phosphoric acid, which are essential conabundance of phosphate of magnesia. stituents of the plants ordinarily cultivated.t Plants obtain their phosphoric acid from These other matters, we must suppose, the soil. It is a constituent of all land capa- supply, in part at least, the place and.perble of cultivation, and even the heath at form the functions of the substances just LiAneburg contains it in appreciable quan- named. We may thus regard common salt, tity. Phosphoric acid has been detected sulphate of potash, nitre, chloride of potassium, and other matters, as necessary con* Professor Connall was lately kind enough to stituents of several plants. show me about half an ounce of a saline powder, Clay-slate contains generally small quanwhich had been taken from an interstice in the tities of oxide of copper; and soils formed body of a piece of teak timber. It consisted from micaceous schist contain some metallic sentially of phosphate of lime, with small quan- fluorides. Now, small quantities of these tities of carbonate of line and phosphate of ma- fluorides. ow, small quantities of these nesia. This powder had been sent to Sir David substances also are absorbed into plants, alBrewster from India, with the assurance that it though we cannot affirm that they are newas the'same substance which usually is found in cessary to them. the hollows of teak timber. It has long been It appears that in certain cases flouride of known that silica, in the form of tabasbeer, is se- calcium may take the place of phosphate creted by the bamboo; but I am not aware that calcium may take the place of phosphate phosphates have been found in the same condi- of lime in the bones and'teeth; at least it is tion. Without more precise information, we must impossible otherwise to explain its constant therefore suppose that they are left in the hollows presence in the bones of antediluvian aniby the decay of the wood. Decay is a slow pro- mals, by which they are distinguished from cess of combustion, and the incombustible ashes must remain after the organic matter has been consumed. But if this explanation be correct, the * See the analyses of soils in the Appendix. wood of' the teak-tree must contain an enormous t For more minute information regarding soils quantity of' earthy phosphates. —ED. see the supplementary chapter at the end Of Part 1. * o~~~~~~~~f 54 AGRICULTURAL CHEMISTRY. those of a later period. The bones of hu- belong to those which are termed fallowman skulls found at Pompeii contain as crops, and the cause wherefore they do not much fluoric acid as those of animals of a exercise any injurious influence on corn former world, for if they be placed in a state which is cultivated immediately after them of powder in glass vessels, and,digested is, that they do not extract the alkalies of with sulphuric acid, the interior of the ves- the soil, and only a very small quantity of sel will, after twenty-four hours, be found phosphates. powerfully corroded (Liebig;) whilst the It is evident that two plants growing bebones and teeth of animals of the present side each other will mutually injure one day contain only traces of it. (Berzelius.) another, if they withdraw the same food De Saussure remarked that plants require from the soil. Hence it is not surprising quantities of the component parts of soils in that the wild chamomile (M]atricaria Chamodifferent stages of their developement; an milla) and Scotch-broom (S artiunt Scopaobservation of much importance in consider- rium) impede the growth of corn, when it ing the growth of plants. Thus wheat is considered that both yield from 7 to 7.43 yielded 79-1000 of ashes a month before blos- per cent. of ashes, which contain io of carsoming, 54-1000 while in blossom, and bonate of potash. The darnel and the flea33-1000 after the ripening of the seeds. It bane (Eirigeron acre) blossom and bear fruit is therefore evident' that wheat, from the at the same time as corn, so that when time of its flowering, restores a part of its growing mingled with it, they will partake organic constituents to the soil, although the of the component parts of the soil, and in phosphate of magnesia remains in the seeds. proportion to the vigour of their growth, The fallow-time, as we have already that of the corn must decrease; for what shown,, is that period of culture during one receives, the others are deprived of. which land is exposed to a progressive dis- Plants will, on the contrary, thrive beside integration by means of the influence of the each other, either when the substances atmosphere, for the purpose of rendering a necessary for their growth which they excertain quantity of alkalies capable of being tract from the soil are of different kinds, or appropriated by plants. when they themselves are not both in the Now, it is evident, that the careful tilling same stages of developement at the same time, of fallow-land must increaseand accelerate On a soil, for example, which contains this disintegration. For the purpose of agri- potash, both.wheat and tobacco may be culture, it is quite indifferent, whether the reared in succession, because the latter plant land is covered with weeds, or, with a plant does not require phosphates, salts which are which does not abstract the potash inclosed invariably present in wheat, but requires in it. Now many plants in the family of only alkalies, and food containing nitrogen. the leguminosce are remarkable on account According to the analysis of Posselt and of the small quantity of alkalies or salts in Riemann, 10,000 parts of the leaves of the general which they contain; the Windsor tobacco-plant contain 16 parts of phosphate bean (Ficia Faba,) for example, contains no of lime, 8.8 parts of silica, and no magnesia; free alkalies, and not one per cent. of the whilst an equal quantity of wheat straw phosphates of lime and magnesia. (Einhof.) contains 47.3 parts, and the same quantity The bean of the kidney-bean (Phaseolis of the grain of wheat 99.45 parts of phosvulgaris) contains only traces of salts. (Bra- phates. (De Saussure.) connot.) The stem of lucerne (JMedicago Now, if we suppose that the grain of sativa) contains only 0.83 per cent., that of wheat is equal to half the weight of its the lentil (Ervum Lens) only 0.57 of phos- straw, then the quantity of phosphates exphate of lime with albumen. (Crome.) tracted from a soil by the same weights of Buck-wheat dried in the sun yields only wheat and tobacco must be as 97.7:16. 0.681 per cent. of ashes, of which 0.09 parts This difference is very considerable. The are soluble salts. (Zenneck.)> These plants roots of tobacco, as well as those of wheat, extract the phosphates contained in the soil, * The small quantity of phosphates which the but they restore them again, because they seeds of the lentils, beans, and peas contain, must are not essentially necessary to the devebe the cause of their small value as articles of nour- lopement of the plant. ishment,since they surpass all other vegetable food p in the quantity of nitrogen which enters into their composition. But as the component parts of the --- bones (phosphate of lime and magnesia) are absent, they satisfy the appetite without increasing the CHAPTER VIII. strength. The following is an analysis of lentils (Playfair.) 6.092 grammes lost 0.972 grammes of water at 2120. 0.566 grammes, burned with ox- ON THE ALTERNATION OF CROPS. ide of copper, gave 0.910 grammes carbonic acid and 0.336 grammes of water. The lentils on IT has long since been found by experience, combustion with oxide of copper, yielded a gas, that the growth of annual plants is rendered in which the proportion of the nitrogen to the car- imperfect, and their crops of fruit or herbs bonic acid was as 1 to 16. C arbon 44.45 less abundant, by cultivating them in sucHydrogen 6.59 cessive years on the same soil, and that, in Nitrogen 6.42 spite of the loss of time, a greater quantity Water 15.95 of grain is obtained when a field is allowed ALTERNATION OF CROPS, 55 to lie uncultivated for a year. During this plication of chemical discoveries? A future interval of rest, the soil, in a great measure, generation, however, will derive incalcularegains, its original fertility. ble advantage from these means of help. It has been further observed, that certain Of all the views which have been adopted plants, such as peas, clover, and flax, thrive regarding the cause of the favourable effects on the same soil only after a lapse of years; of the alternations of crops, that proposed whilst others, such as hemp, tobacco, helian- by M. Decandolle alone deserves to be menthus tuberosus, rye, and oats may be culti- tioned as resting on a firm basis. vated in close succession when proper ma- Decandolle supposes that the roots of nure is used. It has also been found, that se- plants imbibe soluble matter of every kind veral of these plants improve the soil, whilst from the soil, and thus necessarily absorb a others, and these are the most numerous, number of substances which are not adapted impoverish or exhaust it. Fallow turnips, to the purposes of nutrition, and must subcabbage, beet, spelt, summer and winter sequently be expelled by the roots, and rebarley, rye and oats, are considered to be- turned to the soil as excrements. Now, as long to the class which impoverish a soil; excrements cannot be assimilated by the whilst by wheat, hops, madder, late turnips, plant which ejected them, the more of these hemp, poppies, teasel, flax, weld, and lico- matters which the soil contains, the more rice, it is supposed to be entirely exhausted. unfertile must it be for the plants of the The excrements of man and animals have same species. These excrementitious matbeen employed from the earliest times for ters may, however, still be capable of assithe purpose' of increasing the fertility of milation by another kind of plants, which soils; and it is completely established by all would thus remove them from the soil, and experience, that they restore certain consti- render it again fertile for the first. And if tuents to the soil, which are removed with the plants last grown also expel substances the roots, fruit or grain, or entire plants from their roots, which can be appropriated grown upon it. as food by the former, they will improve the But it has been observed that the crops are soil in two ways. not'always abundant in proportion to the Now a great number of facts appear at quantity of'manure employed, even: al- first sight to give a high degree of probabithough it may have been of the most power- lity to this view. Every gardener knows ful kind; that the produce of many plants, that a fruit-tree cannot be made to grow on for example, diminishes, in spite of the ap- the same spot where another of the same parent replacement by manure of' the sub- species has stood; at least not until after a stances removed from the soil, when they lapse of several years. Before new vineare cultivated on the same field for several stocks are planted in a vineyard from which years in succession. the old have been rooted out, other plants On the other hand it has been remarked, are cultivated on, the soil for several years. that a field which has become unfitted fobr a In connexion with this it has been observed, certain kind of plants was not on that ac- that several plants thrive best when growing count unsuited for another; and upon this beside one Ianother; and on the contrary, observation, a system of agriculture has that others mutually prevent each other's been gradually founded, the principal ob- developement. Whence it was concluded, ject of which is to obtain the greatest possi- that the beneficial'influence in the former ble produce with the least expense of ma- case depended on a mutual interchange of nure.' nutriment between the plants, and the inNow it was deduced from all the foregoing jurious one in the latter on a poisonous facts that plants require' for their growth action of the excrements of each on the different constituents of soil, and it was other respectively. very soon perceived, that an alternation-of A series of experiments, by Macairethe plants cultivated maintained the fertility Princep gave great weight to this theory. of a soil quite as well as leaving it at rest or He proved beyond all doubt that many fallow. It was evident that all plants must plants are capable of emitting extractive give back to the soil in which they grow matter from their roots. He found that'the different proportions of certain substances, excretions were greater during the nig(ht which are capable of being used as food by than by day (?), and that the water in a succeeding generation. which plants of the family of the LegumniBut agriculture has hitherto never sought nosce grew acquired a brown colour. Plants aid from chemical principles, based on the of the same species placed in water imknowledge of those substances which plants pregnated with these excrements were irmextract from the soil on which they grow, peded in their growth, and faded p-remaand of those restored to the soil by means of turely, whilst, on. the contrary, corn-plants manure. The discovery of such principles grew vigorously in it, and the colour of the will be the task of a future generation, for water diminished sensibly; so that it apwhat can be expected from the present, peared as if a certain quantity of the excrewhich recoils with seeming distrust and ments of the Leguminosce had really been aversion from all the means of assistance absorbed by the corn-plants. These exoffered it by chemistry, and which does not periments afforded, as their main result, understand the art of making a rational ap- I that the characters and properties ol the ax 56 AGRICULTURAL CHEMISTRY. crements of different species of plants are rishment of another of the same species, different from one'another, and that some but it is possible that an herbivorous animal, plants expel excrementitious matter of an a fish, or a fowl, might find in them undiacrid and resinous character; others mild gested matters capable of being digested in substances resembling gum. The former of their organism, from the very circumstance these, according to Macaire-Princep, may of their organs of digestion having a different be regarded as poisonous, the latter as nu- structure. This is the only sense in which tritious. we can conceive that the excrements of one The experiments of Macaire-Princep afI:animal could yield matter adapted for the ford positive proof that the roots, probably nutrition of another. of all plants, expel matters, which cannot A number of substances contained in the be converted in their organism either into food of animals pass through their alimentary woody fibre, starch, vegetable albumen, or organs without change, and are expelled gluten, since their expulsion indicates that from the system; these are excrements but they are quite unfitted for this purpose. not excretions. Now a part of such excreBut they cannot be considered as a confir- mentitious matter might be assimilated in mation of the theory of Decandolle, for they passing through the digestives apparatus ofleave it quite undecided whether the sub- another animal. The organs of secretion stances were extracted from the soil, or form combinations of which only the eleformed by the plant itself from food received ments were contained in the food. The from another source. It is certain that the production of these new compounds is a gummy and resinous excrements observed consequence of the changes which the food by Macaire-Princep could not have been undergoes in becoming chyle and chyme, contained in the soil, and as we know that and of the further transformations to which the carbon of a soil is not diminished by these are subjected by entering into the culture, but, on the contrary, increased, we composition'of-the organism. These matmust conclude that all excrements which ters, likewise, are eliminated in the excrecontain carbon must be formed from the food ments, which must therefore consist of two obtained by plants from the atmosphere. different kinds of substances, namely, of the Now, these excrements are compounds, indigestible constituents of the food, and of produced in consequence of the transforma- the new compounds formed by the vital protions of the food, and of the new forms cess. The latter substances have been prowhich it assumes by entering into the com- duced in consequence of the formation of position of the various organs. fat, muscular fibre, cerebral and nervous M. Decandolle's theory is properly a substance, and are quite incapable of being modification of an earlier hypothesis, which converted into the same substances in any supposed that the roots of different plants other animal organism. extracted different nutritive substances from Exactly similar conditions must subsist in the soil, each plant selecting that which the vital processes of plants. When sub-. was exactly suited for its assimilation. Ac- stances which are incapable of being emcording to this hypothesis, the matters in- ployed in the nutrition of a plant exist in capable of assimilation are not extracted the matter absorbed by its roots, they must from the soil, whilst M. Decandolle consi- be again returned to the soil. Such excreders that they are retut-ned to it in the form ments might be serviceable and even indisof excrements. Both views explain how it pensable to the existence of several other happens that after corn, corn cannot be plants. But substances that are formed in raised with advantage, nor after peas, peas; a vegetable organism during the process of but they do not explain how a field is im- nutrition, which are produced, therefore, in proved by lying fallow, and this in propor-. consequence of the formation: of woody fibre, tion to the care with which it is tilled and starch, albumen, gum, acids, &c., cannot kept free from weeds; nor' do they show again serve in any other plants to form the how a soil gains carbonaceous matter by the same constituents of vegetables. cultivation of certain plants, such as lucerne The consideration of these facts enables and sainfoin. us to distinguish the difference between the Theoretical considerations on the process views of Decandolle and those of Macaireof nutrition, as. well as the experience of all Princep. The substances which the former agriculturists, so beautifully illustrated by physiologist viewed as excrements, belonged the experiments of Macaire-Princep, leave to the soil; they were undigested matters, no doubt that substances are excreted from which although not adapted for the nutrition the roots of plants, and that these matters of one plant might yet be indispensable to form the means by which the carbon re- another. Those matters, on the contrary, ceived from humus in the early period of designated as excrements by Macaire-Printheir growth is. restored to the soil. But cep, could only in one form serve for the we may now inquire whether these excre- nutrition of vegetables. It is scarcely nements, in the state in which they are ex- cessary to remark that this excrementitious pelled, are capable of being employed as matter must undergo a change before another food by other plants. season. During autumn and winter it beThe excrements.of a carnivorous animal gins to suffer a change from'the influence contain no constituents fitted ior the nou- of air and water; its putrefaction, and at ALTERNATION OF CROPS. 57 length, by continued contact with the air, is not sufficient in irrigating meadows to which tillage is the means of.procuring, its convert them into marshes, by covering for decay are effected; and at the commence- several months their surface with water, meat of spring -it has become converted, which is not renewed; for the advantage of either in whole or in part, into a substance irrigation consists principally in supplying which supplies the place of humus, by being( oxygen to the roots of plants. The quantity a constant source of carbonic acid. of water necessary for this purpose is very The quickness with which this decay of small, so that it is sufficient to cover the the excrements of plants proceeds depends meadow with a very thin layer, if this be on the composition of the soil, and on its frequently renewed. greater or less porosity. It will take place The cultivation of'meadows forms one of very quickly in a calcareous soil: for the the most important branches of rural ecopower of organic excrements to attract oxy- nomy. It contributes materially to the prosgen and to putrefy is increased by contact perity of the agriculturist by increasing his with the alkaline constituents, and by the stock of cattle, and consequently by furnishgeneral porous nature of' such kinds of soil, ing him with manure, which may be applied which freely permit the access of air. But to the augmentation of his crops. Indeed, it requires a longer time in heavy soils con- the great progress which has been made in sisting of loam or clay. Germany in the improvement of cattle is The same plants can be cultivated with mainly attributable to the attention which is advantage on one soil after the second year, devoted in that country to the culture of but in others not until the fifth or ninth, meadows. The environs of Siegin, in Nasmerely on account of the change and de- sau, are particularly famed in this respect, struction of the excrements, which have an and every year a large number of young injurious influence on the plants being com- farmers repair to it, fbr the purpose of studypleted in the one, in the second year; in the ing this branch of agriculture in situ. In others, not until the ninth. that district the culture of grass has attained.In some neighbourhoods clover will not such great perfection, that the produce of thrive till the sixth year. in others not till the their meadow-land far exceeds that obtained twelfth; flax in the second or third year. in any other part of Germany. This is efAll this depends on the. chemical nature of' fected simply by preparing the ground in the soil, for it has been found by experience such a manner as to enable it to be irrigated that in those districts where the intervals at both in spring and in autumn. The surface which the same plants- can be cultivated of the, soil is fitted to suit the locality, and with advantage are very long, the time can- the quantity of water which can be cornnot be shortened even by the use of the most manded. Thus if the meadows be situated powerful manures. The destruction of the upon a declivity, banks of from one to two peculiar excrements of one crop must have feet in height are raised at short distances taken place before a new crop can be pro- from each other. The water is admitted by duced. small channels upon the most elevated bank, Flax, peas, clover, and even potatoes, are and allowed to discharge itself over the sides plants the excrements of which, in argilla- in such a manner as to run upon the bank ceous soils, require the longest time, for their situated below. The grass grown upon conversion into humus; but it is evident meadows irrigated in this way is three or that the use of alkalies and burnt lime, or four times higher than that obtained from even small quantities of ashes which have fields which are covered with water that is not been lixiviated, must enable a soil to deprived of all egress and renewal. permit the cultivation of the same plants in It follows from what has preceded that the a much shorter time. advantage of the alternation of crops is owA soil lying fallow owes its earlier fer- ing to two causes. tility, in part, to the destruction or conver- A fertile soil ought to afford to a plant all sion into humus of the excrements contained the inorganic bodies indispensable for its exin it, which is effected during the fallow istence in sufficient quantity and in such season, at the same time that the land is condition as allows their absoription. exposed to a farther disintegration. All plants require alkalies, which are In the soils in the neighbourhood of the contained in some, in the Graminece for exIRhine and' Nile, which contain much pot- ample, in the form of silicates; in otners, ash, and where crops can be obtained in close in that of tartrates, citrates, acetates, or oxsuccession from the same field, the. fallowing alates. of the land is superseded by the inundation; When these alkalies are in combination the irrigation of meadows effects the same with silicic acid, the ashes obtained by the purpose. It is because the water of rivers incineration of the plant contain no carbonic and streams contains oxygen in solution that acid; but when. they are united with organic it effects the most complete and rapid putre- acids, the addition of a mineral acid to their faction of the excrements contained in the ashes causes an effervescence. soil which it penetrates, and in which it is A third species of plants requires phoscontinually renewed. If it was the water phate of lime, another phosphate of magalone which produced this effect, marshy nesia, and several do not thrive without carmeadows should be most fertile.. Hence it bonate of lime, 8 .58 ~ ~ R.IAGRICULTURAL CHEMISTRY. Silicic acid is the first solid substance The sowing of a field with fallow plants, taken up by plants; it appears to be the ma- such as clover, rye, buck-wheat, &c., and terial from which the formation of the wood the incorporation of plants, when nearly at takes its origin, acting like a grain of sand blossom, with the soil, affect this supply of around which the first crystals form in a so- humus in so far, that young plants subselution of a salt which is in the act of crys- quently growing in it find, at a certain petallising. Silicic acid appears to perfoirm riod of their growth, a maximum of nuthe functions of woody fibre in the Equise- triment, that is, matter in the process of detacere and bamlboos,~ just as the crystalline cay. salt, oxalate of lime, does in many of the The same end is obtained, but with much lichens. greater certainty, when the field is planted When we grow in the same soil for seve- with sainfoin or lucerne.? These plants are ral years in succession different plants, the remarkable on account of the great ramififirst of which leaves behind that which the cation of their roots, and strong developesecond, and the second that which the third ment of their leaves, and for requiring only may require, the soil will be a fruitful one a small quantity of inorganic matter. Until for all the three kinds of produce. If the they reach a certain period of their growth, first plant, for example, be wheat, which they retain all the carbonic acid and ammoconsumes the greatest part of the silicate of nia which may have been conveyed to them potash in a soil, whilst the plants which by rain and. the air, for that which is not succeed it are of such' a kind as require absorbed by the soil is appropriated by the only small quantities of potash, as is the leaves; they also possess an extensive four case with Legumninosce, turnips, potatoes, or six-fold.surface, capable of assimilating &c., the wheat may be again sowed with these bodies, and of preventing the volstiliadvantage after the fourth year; for during zation of the ammonia from the soil, by the interval of three years the soil Will, by completely covering it in. the action of the atmosphere, be rendered An immediate consequence of the procapable of again yielding silicate of potash duction of the green principle of the leaves, in sufficient quantity for the young plants. and of their remaining component parts, as The same precaution must be observed well as those of the stem, is the equally with regard to the other inorganic constitu- abundant excretion of organic matters into ents, when it is desired to grow different the soil from the roots. plants in succession on the same soil: for a The favourable influence which this exsuccessive growth of plants which extract ercises on the land, by furnishing it with the same component parts, must gradually matter capable of being converted into hurender it incapable of producing them. mus, lasts for several years, but barren spots Each of these plants during its growth re- gradually appear after the lapse of some turns to the soil a certain quantity of sub- time. Now it is evident that, after from six stances containing carbon, which are gra- to seven years, the ground must become so dually converted into humus, and are for the impregnated with excrements that every most part equivalent to as much carbon as fibre of the root will be surrounded. with the plants had formerly extracted from the them. As they remain for some time in a soil in a state of carbonic acid. But al- soluble condition, the plants must absorb though this is sufficient to bring many plants part of them and suffer injurious effects in to maturity, it is not enough to furnish their consequence, because they are not capable different organs with the greatest possible of assimilation. WVhen such a field is obsupply of nourishment. Now the object of served for several years, it is seen that the agriculture is to produce either articles of barren spots are again covered with vegetacommerce, or food for man and animals; tion, (the same plants being always supbut a maximum of produce in plants is al- posed to be grown,) whilst new spots beways in proportion to the quantity of nutri- come bare and apparently unfruitful, and so ment supplied to them in the first stage of on alternately. - lThe causes which produce their developement. this alternate barrenness and fertility in the The nutriment of young plants -consists different parts of the land are evident. The of carbonic acid, contained in the soil in the excrements upon the barren spots receiving form of humus, and of nitrogen in the form no new addition, and being subjected to the of ammonia, both of whichl must be sup- influence of air and moisture, they pass into plied to the plants, if the desired purpose is putrefaction, and their injurious influence to be accomplished. The formation of ammonia cannot be effected on cultivated land, The altornation of crops with sainfoin and inbut humus may be artificially produced; and cern is now universally adopted in Bingen and its this must be considered as an important ob- vicinity, as well as in the Palatinate; the fields in ject in the alternation of crops, and as the these districts receive manure only once every second reason of its peculiar advantages.. nine years. In the first years after the land has been manured turnips are sown upon it, in the next following years barley, with sainfoin or lu. * Silica is found in the joints of bamboos, in the cerne; in the seventh year potatoes, in the eighth form of small round globules, which have received wheat, in the ninth barley; on the tenth year it is the name of TabaIsheer, and are distinguished by manured, and then the same rotation again takes their remarkable optical properties. place. ON MANURE. 59 ceases. The plants now find those sub- ments of animals, which are emplos d as stances which formerly prevented their manure, are all of'alike nature and power, growth removed, and in their place meet and whether they, in every case, administer with humus, that is, vegetable matter in the to the necessities of a plant by an identical act of decay. mode of action. These points may easily We can scarcely suppose a better means he determined by ascertaining the composi-. of producing humus than by the growth of tion of the animal excrements, because we plants, the leaves of which are food for ani- shall thus learn what substances a soil really mals; for they prepare the soil for plants of receives by their means. According to the every other kind, but particularly for those common view, the action of' solid animal to which, as to rape and flax, the presence excrements depends on the decaying orgaof humus is the most essential condition of nic matters which replace the humus, and growth. on the presence of' certain compounds of The reasons why this interchange of crops nitrogen, which are supposed to be assimiis so advantageous-the principles which lated by plants, and employed in the proregulate this part of agriculture, are, there- duction of gluten and other azotised subfore, the artificial production of humus, and stances. But this view requires further the cultivation of different kinds of plants confirmation with respect to the solid excreupon the same field, in such an order of ments of animals, for they contain so small succession, that each shall extract only cer- a proportion of nitrogen, that they cannot tain components of the soil, whilst it leaves possibly by means of it exercise any inbehind or restores those which a second or fluence upon vegetation. third species of plant may require for its We may form a tolerably correct idea of growth and perfect developement. the chemical nature of the animal excreNow, although the quantity of humus in nlent without further examination, -by coma soil may be increased to a certain degree paring the excrements of a dog with its by an artificial cultivation, still, in spite of food. When a dog is fed with flesh and this, there cannot be the smallest doubt that bones, both of which consist in great part a soil must gradually lose those of its con- of organic substances containing nitrogen, a stituents which are removed in the seeds, moist white excrement is produced, which roots, and leaves of the plants raised upon crumbles gradually to a dry powder in the it. The fertility of a soil cannot remain un- air. This excrement consists of the phosimpaired, unless we replace in it all those phate of lime of the bones, and contains substances of which it has been thus de- scarcely -1- part of its weight of foreign prived. organic substances. The whole process ot Now this is effected by manure. nutrition in an animal consists in the progressive extraction of all the nitrogen from the food, so that the quantity of this element CH~A[PT~ER IX. found in the excrements must always be less than that contained in the nutriment. OF MANURE. The analysis of the excrements of a horse by Macaire and Marcet proves this fact cornWHEN it is considered that every consti- pletely. The portion of excrements subWtent of the body of man and animals is de- jected to analysis was collected whilst fresh, rived from plants, and that not a single and dried in vacuo over sulphuric acid; 100 element is generated by the vital principle, parts of it (corresponding to from 350 to it is evident that all the inorganic constitu- 400 parts of the dung before being dried) ents of the animal organism must be re- contained 0.8 of nitrogen. Now every one garded, in some respect or other, as manure. who has had experience in this kind of anaDuring their life, the inorganic components lvsis is aware that a quantity under one per of plants which are not required by the ani- cent. cannot be determined with accuracy. mal system, are disengaged from the orga- We should, therefore, be estimating its pronism, in the form of excrements. After portion at a maximum, were we to consider their death, their nitrogen and carbon pass it as equal to one-half per cent. It is cerinto the atmosphere as ammonia and car- tain, however, that these excrements are not bonic acid, the products of their putrefac- entirely free from nitrogen, for they emit tion, and at last nothing remains except the ammonia when digested with caustic potash. phosphate of lime and other salts in their The excrements of a cow, on combustion bones. Now this earthy residue of the pu- with oxide bf copper, yielded a gas which trefaction of animals must be considered, in contained one vol. of nitrogen gas, and 26.30 a rational system of agriculture, as a power- vol. of carbonic acid. ful manure for plants, because that which 100 parts of fresh excrements contained has been abstracted from a soil for a series of years must be restored to it, if the land Ntrogen... 0506 is to be kept in a permanent condition of Hydrogen.. 0.824 fertility. Oxygen.. 4.818 Ashes.... 1.748 ANIMAL MANURES. Water...85.900 WVe may now inquire whether the excre- I 100.000 60 AGRICULTURAL CHEMISTRY. Now, according to the analysis of' Bous- smell. 100 parts of the fresh dung of a singault, which merits the greatest confi- horse being dried at 1000 C. (2120 F.) deuce, hay contains one per cent. of nitro- leave from 25 to 30 or 31 parts of solid subgen; consequently in the 25 lbs. of hay stances, and contained, accordingly, from 69 which a cow consumes daily, i of a lb. of' to 75 parts of water., From the dried exnitrogen must have been assimilated. This crements, we obtain, by incineration, variquantity of nitrogen entering into the cornm- able quantities of salts and earthy matters, position of muscular fibre would yield 8'3 according to the nature of the food which lbs. of flesh in its natural condition.* The has been taken by the animal. Macaire and daily increase in size of a cow is, however, Marcet found 27 per cent. in the dung anamuch less than this quantity. We find that lysed by them; I obtained only 10 per cent. the nitrogen, apparently deficient, is actually from that of a horse fed with chopped straw, contained in the milk and urine of the ani- oats, and hay. It results then that with mal. The urine of a milch-cow contains from 3600 to 4000 lbs. of fresh horse-dung, less nitrogen than that of one which does corresponding to 100 lbs. of' dry dung, we not yield milk; and as long as a cow yields place on the land from 2484 to 3000 lbs. of a plentiful supply of milk, it, cannot be fat- water, and from 730 to 900 lbs. of vegetable tened. We must search for the nitrogen of matter and altered gall, and also from 100 the food assimilated, not in the solid, but in to 270 lbs. of salt and other inorganic subthe liquid excrements. The influence which stances. the former exercise on the growth of vege- The latter are evidently the substances to tables does not depend upon the quantity of which our attention should be directed, for nitrogen which they contain. For if this they are the same which formed the compowere the case, hay should possess the same nent parts of the' hay, straw, and oats with influence; that is, from 20 to 25 lbs. ought which the horse was fed. Their principal to have the same power as 100 lbs. of fresh constituents are the phosphates of liure and cow-dung. But this is quite opposed to all magnesia, carbonate of lime and silicate of experience. potash; the first three of these prepondeWhich then are the substances in the ex- rated in the corn, the latter int hay. crements of the cow and horse which exert Thus in 1000 lbs. of horse-dung, we prean influence on vegetation? sent to a field the inorganic substances conWVhen horse-dung is treated with water, tained in 6000 lbs. of hay, or 8300 lbs. of a portion of it to the amount of 3 or 3~ per oats (oats containing 3-1 per cent. ashes accent. is dissolved, and the water is coloured cording'to De Saussure.) This is sufficient yellow. The solution is found to contain to supply 1 crop of wheat with potash and phosphate of magnesia, and salts of soda, phosphates. besides small quantities of organic matters.t The excrements of cows," black cattle, The portion of the dung undissolved by the and sheep, contain phosphate of lime, comwater yields to alcohol a resinous substance mon salt, and silicate of lime, the weight of possessing all the characters of gall which which varies from 9 to 28 per cent., accordhas undergone some change; while the ing to the fodder which the animal receives; residue possesses the properties of saw-dust, the fresh excrements of the cow contain from which all soluble matter has been ex- from 86 to 90 per cent. of water. tracted by water, and burns without any Human faeces have;been subjected to an exact analysis by Berzelius. When fresh they contain, beside 4 of their weight or * 100 lbs. of flesh contain on an average 15'86 water, nitrogen in very variable quantity, of muscular fibre: 18 parts of nitrogen are con- namely, in the minimum 1 ~, in the maxitained in 100 parts of the latter. t Dr. C. T1. Jackson in'his " Geological and Agricultural Survey of Rthode Island," (page 205.) * It has been formerly stated (page 41) that all gives the following analysis of horse-dung:-500 the potash contained in the food of a cow is again grains, dried at a heat a little above that of boiling discharged in its excrements. The same also water, lost 357 grains of water. The dry mass takes place with the other inorganic constituents weighing 143 grains was burned, and left 85 grains of fbod, either when they are not adapted for asof ashes, of which 4-80 grains were soluble in similation, or when present in superabundant dilute nitric acid, and 3'20 insoluble. The ashes quantities. The value of manure may thus be being analysed, gave artificially increased. We lately saw, for exSilica... ~ 3'2 ample, some cow-dung, sent by a farmer, who Phosphate of lime... 0-4 wished to ascertain the cause of its increased Carbonate of lime.. 1-5 value. He had formerly employed this manure Phosphate of magnesia and soda. 2'9 for his land, but with so little advantage that he - found it more profitable to dry it, and use it as 8'0 fuel. On inquiry, it was found, that his cows had It consists, then, of the following ingredients:- been fed upon oil-cake. This species of food Water.. 357'0 is particularly rich in phosphates. More of these'Vegetable fibre and animal matter 135'0 salts being present than were requisite for the Silica.. -. 3'2 purpose of assimilation, they were removed from Phosphate of lime. 0'4 the system in the form of excrementitious matter, Carbonate of lime.. 1'5 and in a condition adapted for the uses of plants. Phosphate of magnesia and soda. 2'9 The fact that particular kinds of food enrich or -.. impoverish the manure obtained from the cattle fed 500'0 upon them, has repeatedly been observed.-Eo. OF MANURE. 61'~ mum 5 per cent. In all cases, however, with the corn and cattle, and this portion they were richer in this element than the will accumulate in the neighbourhood of excrements of' other animals. Berzelius large towns. The loss thus suffered must obtained by the incineration of 100 parts of be compensated for in a well-managed farm, dried excrements, 15 parts of ashes, which and this is partly done by allowing the fields were principally composed ofthephosphates to lie in grass. In Germany, it is considered of lime and magnesia. that for every 100 acres of corn-land, there The following quantitative organic ana- must, in order to effect a profitable cultivalysis has recently been executed for the pur- tion, be 20 acres of pasture-land, which propose of ascertaining the proportion ofcarbon, duce annually, on an average, 500 lbs. of nitrogen; and inorganic matter contained in hay. Now, assuming that the ashes of the faces, in comparison with the food taken.? excrements of the animals fed with this hay (Playfair.) amount to 6.82 per cent., then'341 lbs. of Carbon... 4524 the silicate of lime and posphates of magneHydrogen. 6'88 sia and limle must be yielded by these excreNitrogen (average). 4'00 ments, and will in a certain measure comOxygen.. 30'30 pensate for the loss which the corn-land had Ashes... 13'58 sustained. The inorganic matter contained in the The absolute loss in the salts of phosphoexcrements analyzed is nearly two per cent. ric acid, which are not again replaced, is less than that found by Berzelius; but the spread over so great an extent of surface, proportion always varies, according to the that it scarcely deserves to be taken acnature of the food. count of. But the loss of phosphates is It is quite certain that'the vegetable con- again replaced in the pastures by the ashes stituents of the excrements with which we of the wood used in our houses for fiel. manure our fields cannot be entirely without We could keep our fields in a constant influence upon the growth of the crops on state of fertility by replacing every year as them, for they will decay, and thus furnish mtch as we remove from them in the form carbonic acid to the young plants. But it of produce; but an-increase of fertility, and cannot be imagined that their influence is consequent increase of crop, can only be very great, when it is considered that a good obtained when we add more to them than soil is manured only once every six or seven we take away. It will be found, that of two years, or once every eleven or twelve years, fields placed under'conditions otherwise when sainfoin or lucerne has been raised on similar, the one will be most fruitful upon it, that the quantity of carbon thus given to which the plants are enabled to appropriate the land corresponds to only 5-8 per cent. of more easily and in greater abundance those what is removed in the form of herbs, straw, contents of the soil which are essential to and grain; and farther that the rain-water their growth and developement. received by a soil contains much more car- From the foregoing remarks it will readily bon in the form of carbonic acid than these be inferred, that for animal excrements, vegetable constituents of the manure. other substances containing their-essential The peculiar action then, of the solid ex- constituents may be substituted. In Flancrements is limited to their inorganic con- ders, the yearly loss of the necessary matters stituen.ts, which thus restore to a soil that in the soil is completely restored by covering which is removed in the form of corn, roots, the fields with ashes of wood or bones, or grain. When we manure land with the which may or may not have been lixiviated, dung of the cow or sheep, we supply it and of which the greatest part consists of with silicate of potash and some salts of the phosphates of lime and magnesia, The phosphoric acid.. In human faeces we give great importance of manuring with ashes it the phosphates of lime and magnesia; has been long recognised by agriculturists and in those of the horse, phosphate of as the result of experience. So great a magnesia, and silicate of potash. In the value, indeed, is attached to this material in straw which has served as litter, we add a the vicinity of Marburg and in the Wettefarther quantity of silicate of potash and raun, that it is transported as a manure phosphates; which, if the straw be putre- from the distance of 18 or 24 miles. Its use flied, are in exactly the same condition in will be at once perceived, when it is conwhich they were before being assimilated. sidered that the ashes, after having been It is evident, therefore, that the soil of a washed with water, contain silicate of pot field will alter but little, if we collect and ash exactly in the same proportion as in distribute the dung carefully; a certain por- straw (10 Si O 3 + K O.,) and that their tion of the posphates, however, omusthbe lost only other constituents are salts of phosphoevery year, being removed from the land ric acid. But ashes obtained from various kinds of trees are of very unequal value for this pur*The details of the analysis are as follows:- pose; those from oak-wood are the least, 2.356 grammes left 0'320 gramme ashes after incineration; these consisted of the phosphate of' lime and magnesia. 0'352 gramme yielded, on * Two well-known agricultural districts; the comaustion with oxide of copper, 0'576 gram., first in Hesse-Cassel, the second in Hesse-Darmcarbonic acid, and 0'218 gram. water. (L. P.) stadt. F 62 AGRICUL' URAL CHEMISTRY. and those from beech the most serviceable. more speedily and efficaciously after neir. The ashes of oak-wood contain only traces boiled. This is probably owing to the rt of phosphates, those of beech the fifth part moval of fatty matter, the presence of whic of their weight, and those of the pine and fir impedes the putrefaction of the gelatin con from 9 to 15 per cent. The ashes of pines tained in them. from Norway contain an exceedingly small In the manufactories of glue, many hunquantity of phosphates, namely, only 1-8 dred tons of a solution of phosphates in muper cent. of phosphoric acid. (Berthier.) riatic acid are yearly thrown away as being With every 100 lbs. of the lixiviated ashes useless. It would be important to examine of the beech which we spread over a soil, whether this solution might not be substiwe furnish as much phosphates as 460 lbs. tuted for the bones. The free acid would. of fresh human excrements could yield. combine with the alkalies in the soil, espeAgain, according to the analysis of De cially with the lime, and a soluble salt Saussure, 100 parts, of the ashes of the grain would thus be produced, which is known of wheat contain 32 parts of soluble, and to possess a favourable action upon the 44-5 of insoluble phosphates, in all 76-5 growth of plants. This salt, muriate of parts. Now the ashes of wheat straw con- lime (or chloride of calcium,) is one of tain 11-5 per cent. of the same salts;. hence those compounds which attracts water from with every 100 lbs. of the ashes of the beech, the atmosphere with great avidity, and in we supply a field with phosphoric acid suf- dry lands might advantageously supply the ficient for the production of 3820 lbs. of place of gypsum in decomposing carbonate straw (its ashes being calculated at 4-3 per of ammonia, with the formation of sal-amcent., De Saussure,) or for 15-18000 lbs. of moniac and carbonate of lime. A solution corn, the ashes of which amount, according of bones in muriatic acid placed on land in to De Saussure, to 1-3 per cent. autumn or in winter would, therefore, not Bone manure possesses a still greater im- only restore a necessary constituent of the portance in this respect. The primary soil, and attract moisture to it, but would sources from which the bones of animals also give it the power to retain all the amare derived are, the hay, straw, or other monia which fell upon it dissolved in the substances which they take as food. Now, rain during the period of six months. if we admit that bones contain 55 per The ashes of brown coal and peat often cent. of the phosphates of lime and magne- contain silicate of potash, so that it is evisia (Berzelius,) and that hay contains as dent that these might completely replace one much of them as wheat-straw, it will follow of the principal constituents of the dung that 8 lbs. of bones contain as much phos- of the cow and horse, and they contain also phate of lime as 1000 lbs. of hay or wheat- some phosphates. Indeed they are much straw, and 2 lbs. of it as much as 1000 lbs. esteemed in the Wetterau as manure for of the grain of wheat or oats. These num- meadows and moist land. bers express pretty nearly the quantity of It is of much importance to the agriculphosphates which a soil yields annually on turist that he should not deceive himself rethe growth of hay and corn. Now the ma- specting the causes which give the peculiar nure of an acre of land with 40 lbs. of bone action to-the substances just mentioned. It dust is sufficient to supply three crops of is known that they possess a very favourwheat, clover, potatoes, turnips, &c., with able influence on vegetation; and it is likephosphates. But the form in which they wise certain that the cause of this is their are restored to a soil does not appear to be a containing a body, which, independently of matter of indifference. For the more finely the influence which it exerts by virtue of its the bones are reduced to powder, and the form, porosity, and capability of attracting more intimately they are mixed with the and retaining moisture, also assists in mainsoil, the more easily are they assimilated. taining the vital processes in plants. If it be The most easy and practical mode of effect- treated as an unfathomable mystery, the naing their division is to pour over the bones, ture of this aid will never be known. in a state of fine powder, half of their weight In medicine, for many centuries, the mode of sulphuric acid diluted with three or four of action of all remedies was supposed to be parts of water, and after they have been di. concealed by the mystic veil of Isis, but gested for some time, to add one hundred now these secrets have been explained in a parts of water, and sprinkle this mixture over the field before the plough. In a few * Immense quantities of bran are used in all seconds, the free acids unite with the bases print-works, for the purpose of clearing printed contained in the earth, and a neutral salt is goods. After having served this purpose, it is formed-in avery fine state of division. Ex- thrown away. But the insoluble part of bran periments instituted on a soil formed from contains much phosphates of magnesia and soda; periments instituted on a soil formed from it would, therefore, be useful to preserve it as a grauwacke, for the purpose of ascertaining manure. This has been done for some years in a the action of manure thus prepared, have farm with which I am connected, and its value as distinctly shown that neither corn, nor a manure has been found so great that it is much:kitchen-garden plants, suffer injurious ef- preferred to cow-dung. In some works this waste fects in consequence, but that on the con- bran is heaped up into little hillocks, which might be disposed of as a manure, instead of being an trary they thrive with much more aigour. annoyance on account of the space which it occIt has also'been found that bones, act pies. —ED. OF MANURE. 63 very simple manner. An unpoetical hand this element. The leaves, which nourish has pointed out the cause of the wonderful the woody matter, the roots, from which the and apparently inexpllcable healing virtues leaves are formed, and which prepare the of the springs in Savoy, by which the inha- substances for entering into the composition bitants cured their goitre; it was shown that of the fruit, and, in short, every part of the they contain small quantities of iodine. In organism of a plant, contain azotised nlatter burnt sponges used for -the same purpose, in very varying proportions, but the.seeds the same element was also detected. The and roots, are always particularly rich in extraordinary efficacy of Peruvian bark was them. found to depend on a sniall quantity of a Let us now examine in what manner the crystalline body existing in it, viz. quinine; greatest possible production of substances and the causes of the various effects of containing nitrogencanbeeffected. Nature, opium were detected in as many different by means of the atmosphere, furnishes niingredients of that drug. trogen to a plant in quantity sufficient for Calico-printers used for a long time the its normal growth. Now its growth must solid excrements of the cow, in order to be considered as normal, when it produces brighten and fasten colours on cotton goods; a single seed capable of reproducing the this material appeared quite indispensable, same plant in the following year. Such a and its action was ascribed to a latent prin- normal condition would suffice for the exciple which it had obtained from the living istence of plants, and prevent their extincorganism. But since its action was known tion, but they do not exist for themselves to depend on the phosphates contained in it, alone; the greater number of animals deit has been completely replaced by a mix- pend on the vegetable world for food, and ture of salts, in which the principal con' by a wise adjustment of nature, plants have stituents are the phosphates of soda and the remarkable power of converting, to a lime.* certain~ degree, all the nitrogen offered to Now all such actions depend on a definite them into nutriment for animals. cause, by ascertaining which we place the XWe may furnish a plant with carbonic actions themselves at our command. acid, and all the materials which it may reIt must be admitted as a principle of agri- quire; we may supply it with humus in the culture, that those substances which have most abundant quantity; but it will not atbeen removed from a soil must be corr- tain complete developement unless nitrogen pletely restored to it, and whether this resto- is also afforded to it; an herb will be formed, ration be effected by means of excrements, but no grain; even sugar and starch may ashes, or bones, is in a great measure a mat- be produced, but no gluten. ter of indifference. A time will come when But when we give a plant nitrogen in fields will be manured with a solution ofglass, considerable quantity, we enable it to attract (silicate of' potash,) with the ashes of burnt with greater energy from the atmosphere straw, and with salts of phosphoric acid, the carbon which is necessary for its nutriprepared in chemical manufactoriesj exactly'tion, when that in the soil is not sufficient; as at present medicines are given for fever we afford to it a means of fixing the carbon and goitre.. of the atmosphere in its organism. There are some plants which require We cannot ascribe much of- the power humus, and do not restore it to the soil by of the. excrements of black cattle, sheep, their excrements; whilst others can do with- and horses, to the nitrogen which they conoutt it altogether, and add humus to a soil tain, for its quantity is too minute. But that which contains it in small quantity. Hence contained in the faces of man is proportiona rational system of agriculture would em- ably much greater, although by no means ploy all the humus at command for the sup- constant. In the faeces of the inhabitants of ply of the former, and not expend any of it towns, for example, who feed on animal for the latter; and would in fact make use matter, there is much more of this constiof them for supplying the others with tuent than in those of peasants, or of such hum us. people as reside in the country. The feces We have now considered all that is requi- of those who live principally on bread and site in a soil, in order to furnish its plants potatoes are similar in composition and prowith the materials necessary for the forma- perties to those of animals. tion of the woody fibre, the grain, the roots, All excrements have in this respect a very and the stem, and now proceed to the con- variable and relative value. Thus those of sideration of the most important object of black cattle and horses are of great use on agriculture, viz. the production of nitrogen soils consisting of lime and sand, which in a form capable of assimilation-'the pro- contain no silicate of potash and phosphates; duction, therefore, of substances containing whilst their value is much less when applied to soils formed of argillaceous earth, basalt, * This mixture of salts is sold to calico-printers granite, porphyry, clinkstone, and even in large quantities under the name of "dung sub- mountain-limestone, because all these constitute." It would be well worth experiment to tain potash in considerable quantity. In try its effects as a manure upon land. Its cost is 3d. or 4d. per pound, and is not, therefore, dearer such soils human excrements are extremely than nitrate of soda, which is now so extensively beneficial, and. increase their fertility in a used.-ED. remarkable degree; they are, of course, as 64 AGRICULTURAL CHEMISTRY. advantageous for other soils also; but for ground. It is these alone, therefore, which the manure of those first mentioned, the ex- enable the soil to exercise a direct influence crements of other animals are quite indis- on plants during the progress oftheir growth, pensable. and not a particle of them escapes being abOF URINE. sorbed by the roots. On account of the formation of this carWe possess only one other natural source bonate of amrnonia the urine becomes alkaof manure which acts by its nitrogen, be- line, although it is acid in its natural state. sides the faeces of animals,-namely, the When it is lost by being volatilized in the urine of man and animals. air, which. happens in most cases, the loss Urine is employed as manure either in suffered is nearly equal to one half of the the liquid state, or with the faeces which weight of the urine employed, so that if we are impregnated with it. It is the urine fix it, that is; if we deprive it of its volatility, contained in them which gives to the solid we increase its action two-fold.. The existfacces the property of emitting ammonia,-a ence of carbonate of ammonia in putrefied property which they themselves possess only urine long since suggested the manufacture in a very slight degree. of sal-ammoniac from this material. When When we examine what substances we the latter salt possessed a high price, this add to a soil by supplying it with urine, we manufacture was even carried on by the find that this liquid contains in solution am- farmer. For this purpose the liquid obtained moniacal salts, uric acid (a substance con- from dunghills was placed in vessels of iron, taining a large quantity of nitrogen,) and and subjected to distillation; the product of salts of phosphoric acid. this distillation was converted into muriate According to Berzelius 1000 parts of hu- of ammonia by the common method. (Deman urine contain: — machy.) But it is evident that such a thoughtless proceeding must be wholly reUrea - Lt o - 30'10 linquished, since the nitrogen of 100 lbs. of Free Lactic acid, Lactate of Amnmonia, and animal matter not separable from them 1714 sal-ammoniac (which contains 26 parts of Uric acid- 100 nitrogen) is equal to the quantity of nitrogen Mucus of the bladder -. 0'32 contained in 1200 lbs. of the grain of wheat, Sulphate of Potash. - 3'71 1480 lbs. of that of barley, or 2755 lbs. of Sulphate of Soda. 3'16 hay. (Boussingault.) Phosphate of Soda - 2'94 Phosphate of Ammonia -. 165 Phosphate of Ammonia -, w 1 65 The carbonate of ammonia formed by the Chloride of Sodium - - -. 4'45 putrefaction of urine, can be fixed or deMuriate of Ammonia - - 150 prived of its volatility in many ways. Phosphates of Magnesia and Lime.' 1-00 If a field be strewed with gypsum, and Silicious earth 0003 then with putrefied urine or the drainings Water - 933.00 of dunghills, all the carbonate of ammonia will be converted into the sulphate which will remain in the soil. If we subtract from the above the urea, But there are still simpler means of effectlactate of ammonia, free lactic acid, uric ing this purpose;-gypsum, chloride of calacid, the phosphate and muriate of ammo- cium, sulphuric or muriatic acid, and supernia; i per cent. of solid matter remains, phosphate of lime, are all substances of a consisting of inorganic salts, which must very low price, and completely neutralise possess the same action when brought on a the urine, converting its ammonia into salts field, whether they are dissolved in, water or which possess no volatility. in urine. Hence the powerful influence of If a basin, filled with concentrated muurine must depend upon its other ingredients, riatic acid, is placed in a common necessary, namely, the urea and ammoniacal salts. so that its surface is in free communication The urea in human urine exists partly as with' the vapours which rise from below, it lactate of urea, and partly in a free state. becomes filled after a few days with crystals (Henry.) Now when urine is allowed to of muriate of ammonia. The ammonia, the putrefy spontaneously, that is, to pass into presence of which the organs of smell amply that state in which it is used as manure, all testify, combines with the muriatic acid and the urea in combination with lactic acid is loses entirely its volatility, and thick clouds converted into lactate of ammonia, and that or fumes of the salt newly formed hang overwhich was free, into volatile carbonate of the basin. In stables the same may be seen. ammonia. The ammonia that escapes in this manner In dung-reservoirs well constructed and is not only entirely lost, as far as our vegetaprotected from evaporation, this carbonate tion is concerned, but-it works also a slow, of ammonia is retained in the state of solu- though ndt less certain destruction of the tion, and when the putrefied urine is spread walls of the building. For when in contact over the land, a part of the ammonia will with the lime of the mortar, it is converted escape with the water which evaporates, into nitric acid, which gradually dissolves but another portion will be absorbed by the the lime. The injury thus done to a buildsoil, if it contains either alumina or iron; ing by the formation of the soluble nitrates, but in general only the muriate, phosphate, has received (in Germany) a special name and lactate of ammonia remain in the -salpeterfrass. OF MANURE. 65 The ammonia emitted from stables, and China is the birth-place of the experinecessaries is always in combination with mental art; the incessant striving after excarbonic acid. Carbonate of ammonia and periments has conducted the Chinese a thousulphateof lime (gypsum) cannot be brought sand years since to discoveries, which have together at common temperatures, without been the envy and admiration of Europeans mutual decomposition. The ammonia enters for centuries, especially in regard to dying into combination with the sulphuric acid, and painting, and to the manufactures of and the carbonic acid with the lime, form- porcelain, silk, and colours for painters. ing compounds which are' not volatile, and These we were long unable to imitate, and consequently destitute of all smell. Now, yet they were discovered by them without if we strew the floors of our stables, from the assistance of scientific principles; for in lime to time, with common gypsum, they the books of the Chinese we find recipes vill lose all their offensive smell, and none and directions for use, but never explana )f the ammonia which forms can be lost, tions of processes. Out will be retained in a condition serviceable as manure; old." The ammonia contained in the fuel fornms With the exception of urea, uric acid nitrate of lime with the lime in the mortar. " All sorts of hair are used as a manure, and barbers' contains more nitrogen than any other sub- shavings are carefully appropriated to that purbersstance generated by the living organism; it pose. The annual produce must be considerable is soluble in water, and can be thus absorbed in'a country where some hundred millions of by the roots of plants, and its nitrogen as- heads are kept constantly shaved. Dung of all similated in the form of ammonia, and of animals, but more especiallynight-soil, isesteemed of above all others. Being sometimes formed into mthe oxalate, ydrocyanate, or carbonate of cakes, it is dried in the sun, and in this state beammonia.' comes an object of sale to farmers, who dilute it Itwould be extremely interesting to study previous to use. They construct large cisterns the transformations which -uric acid suffers or pits, lined with lime plaster, as well as earthen in a living plant. For the purpose of experi-th straw over them ment, the plant should be made to grow in, to prevent evaporation, in which all kinds of vegetables and animal refuse are collected. These charcoal powder previously heated to red- being diluted with a sufficient quantity of liquid, ness, and then mixed with pure uric acid. are left to undergo the putrefactive fermentation, The examination of the juice of the plant, and then applied to the land. In the case of every or of the component parts of the seed or thing except rice, the Chinese seem to manure the ifruit, would be a means of easily detecting plant itself rather than the soil, supplying it co. the differences. piously with their liquid preparation." "The Chinese husbandman," observes Sir G.'NIGHT-SOIL. Staunton, (Embassy, vol. ii.,) " always steeps the seeds he intends to sow in liquid manure, until IN respect to the quantity of nitrogen con- they swell, and germination begins to appear, tained in excrements, 100 parts of the urine which experience has taught him will have the of a healthy man are equal to 1300 parts of effect of hastening the growth of plants, as well the fresh dung of a horse, according to the in the ground in which the seeds are sown. To analyses of Macaire and Marcet, and to 600 the roots of plants and fruit-trees,'the Chinese parts of those of a cow., Hence it is evident farmer applies liquid manure likewise." that it would be of much importance to Lastly, we extract the following from a com. agriculture if none ofthe human i rtwera e omunication to Professor Webster, of Harvard agriculture if none of the human urine reCollege, Uitd States:'-" Human urine is, if lost. The powerful effects of urine as a possible, more husbanded by the Chinese than manure are well known in Flanders,~ but night-soil for manure; every farm, or patch of they are considered invaluable by the Chi- land for cultivation, has a tank, where all sub. nese, who are the oldest agricultural people stances convertible into manure are carefully de. we know. Indeed so much value is attached posited, the~ whole made liquid by adding urine in the proportion required, and invariably applied to the influence of human excrements by. in that state," This is exactly the process folthese people, that laws of the state' forbid lowed, in the Netherlands. See Outlines of Flem. that any of them should be thrown away, ish Husbandry, page 22. and reservoirs are placed in every house, in "The business of collecting ur:ne and night. which they ares collected with the greatest soil employs an immense number of persons, who care. No other kind of manure is used for deposit tubs in every house in the cities for the care. No other kind of manure is used for reception ~~~~their corn-fields.freception of the urine of the inmates, which'estheir corn-fields.]' sels are removed daily, with as much care as our farmers remove their honey from the hives." * See the article "'On the Agriculture of the'When we consider the immense value of nightNetherlands," Journ. Royal Agri. Soc., vol. ii. soil as a manure, it is quite astounding that so part 1, page 43, for much interesting information little attention is paid to preserve it. The quantity. bn this subject. is immense which is carried down by the drains't Davis, in his Ilistory of China, states that in London to the River Thames, serving no other every substance convertible into manure is dili- purpose than to pollute its waters. It has been gently husbanded. "'l'he cakes that remain after shown, by a very simple calculation, that the the'expression of their vegetable oils, horns and value of the manure thus lost amounts annually hoofs reduced to powder, together with soot and to several millions of pounds sterling. A subashes, and the contents of common sewers, are stance, which by its putrefaction generates miasmuch used. The plaster of old kitchens, which mata, may, by artificial means, be rendered totally in China have no chimneys but an opening at the inoffensive, inodorous, and transportable, and yet top, is much valued; so that they will sometimes prejudice prevents these means being resorted to. put a new plaster on a kitchen for the sake of the — ED. 9 2 66 AGRICULTURAL CHEMISTRY. Half a century sufficed to Europeans not ammonia. The mass, when dried by ex,nly to equal but to surpass the Chinese in posure to the air, has lost more than half of the arts and manufactures, and this was the nitrogen which the excrements originally owing merely td the application of correct contained; for the ammonia escapes into principles deduced from the study of che- the atmosphere along with the water which mistry. But how infinitely inferior is the evaporates; and the residue now consists agriculture of Europe to that of China! principally of phosphate of lime, with phosThe Chinese are the most admirable gar- phate and lactate of ammonia, and small deners and trainers of plants, for each of quantities of urate of magnesia and fatty which they understand how to prepare and matter. Nevertheless it is still a very powapply the best-adapted manure. The agri- erful manure, but its value as such would culture of their country is the most perfect be twice or four times as great, if the excrein the world; and there, where the climate ments before being dried were neutralised in the most fertile districts differs little from with a cheap mineral acid. the European, very little value is attached In other manufactories of manure the to the excrements of animals. With us, night-soil, whilst still soft, is mixed with the thick books are written, but no experiments ashes of wood, or with earth, both of which instituted; the quantity of manure consumed substances contain a large quantity ot causby this and that plant is expressed in hun- tic lime; by means of which a complete exdredth parts, and yet we know not what pulsion of all its ammonia is effected, and it manure is! is completely- deprived of smell. But such If we admit that the liquid and solid ex- a residue applied as manure can act only by crements of man amount on an average to the phosphates which it still contains, for I_ lb. daily, (- l1). of urine and. lb. faces,) all the ammoniacal salts: have been decomand that both taken together contain 3 per posed and their ammonia expelled. cent. of nitrogen, then in one year they will The preparation of night-soil is now caramount to 547 lbs., which contain 16-41 lbs. ried on in London to a considerable extent. of nitrogen, a quantity sufficient to yield the Owing to the variable nature of the climate, nitrogen of 800 lbs. of wheat, rye, oats, or artificial means are employed in its desiccaof 900 lbs. of barley. (Boussingault.) tion. The night-soil, after being subjected -This is much more than is necessary to to one or other of the modes of treatment add to an acre of land in order to obtain, described below, is placed upon iron plates with the assistance of the nitrogen absorbed heated by means of furnaces. from the atmosphere, the richest possible As soon as the night-soil is collected, it is crop every year. Every town and farm placed in large broad trenches, until a suffimight thus supply itself with the manure, cient quantity is accumulated for the purwvhich, besides containing the most nitrogen, poses of the- manufacturer. But here it contains also the most phosphates; and if undergoes the same process of putrefaction rotation of the crops were adopted, they to which allusion has been made, and acwould be most abundant. By using, at the quires a peculiarly offensive smell from the same time, bones and the lixiviated ashes evolution of sulphuretted hydrogen and' of wood, the excrements of animals might other gases, which are observed to escape. be completely dispensed with. Unless some means be employed, at this When human excrements are treated in stage of the process, to retain the ammonia, a proper manner; so as to remove the mois- it escapes into the atmosphere in the form ture which they contain without permitting of a carbonate. Various methods have been the escape of ammonia, they may be put proposed to effectthis purpose. Some manuinto such a form as will allow them to be facturers mix the night-soil with chloride of transported even to great distances. lime, and evaporate off the water by the aid This is already attempted in many towns, of heat. This possesses the advantage of and the preparation of night-soil for trans- depriving the excrements of smell, and at portation constitutes not an unimportant the same time partially fixes the ammonia branch of industry. But the manner in which would otherwise escape. Chloride which this is done is the most injudicious of lime always contains a considerable exwhich could be conceived. In Paris, for cess of lime; hence part of the ammonia example, the excrements are preserved in contained in the night-soil is expelled by the houses in open casks, from which they means of it. are collected and placed in deep pits at More simple and economical methods Montfaucon, but are not sold until they have might be employed. A patent, which has attained a certain degree of dryness by eva- been taken out for the preparation of this poration in the air. But whilst lying in the useful manure, states in its specification, receptacles appropriated for them in the that the night-soil is to be mixed with calhouses, the greatest part of their urea is cined mud and finely-divided charcoal. By converted into carbonate of ammonia; lac-, this means, the smell is completely and intate and phosphate' of ammonia are also stantaneously removed, and the ammonia formed, and the vegetable matters contained retained by virtue of the affinity which aluin them putrefy; all their sulphates are de- mina and charcoal exert for that compound. composed, whilst their sulphur forms sul- This plan is both simple and efficacious, but phuretted hydrogen and hydro-sulphate of the ammonia is apt to be expelled by the OF MANURE. 67 application of the heat employed in drying Much speculation has arisen as to the the manure. The addition of a cheap mine- true origin of guano," but the most certain ral acid to the night-soil, before admixture proof is now afforded, that it has been prowith these ingredients, would materially duced by the accumulation of the excreimprove both of the above processes, ments of innumerable sea-fowl which inhabit It would no doubt be highly advantageous the islands upon which it is found. Meyen, in the preparation of manures, to prepare the latest writer upon this subject, comthem so that they contained all the ingredi- pletely coincides with this opinion; for he ents necessary for the supply of the plants sayst —" Their number is Legion; they to which they are applied. But these will completely cloud the sun, when they rise of course vary according to the nature of from their resting-place in the morning in the soils and plants for which they are in- flocks of miles in length." Yet, notwithtended. Thus: bones, soap-boilers' waste, standing their great number, thousands of nitrate of soda, and ashes of wood, will years must have elapsed, before the excreoften be found to form advantageous addi- ments could have accumulated to such a tions. Sulphate of magnesia (Epsom salts) thickness as they possess at present. Guano would, in most cases, form. an invaluable has been used by the Peruvians as a manure ingredient in prepared night-soil. (See Sup- since the twelfth century; and its value was plementary Chapter on Soils.) The pro- considered so inestimable, that the governducts of the decomposition proceeding from ment of the Incas issued a decree, by which the action of this salt upon night-soil are, capital punishment was inflicted upon any sulphate of ammonia, phosphate of mag- person found destroying the fowl on the nesia, and the double phosphate of magnesia Guano islands. Overseers were also apand ammonia. Now all these salts exert a pointed over each province, for the purpose very favourable'influence upon vegetation, of insuring them further protection. Under and the phosphate of magnesia is, in many this state of things, the accumulation of the cases, perfectly indispensable to the growth excrements may have well taken place. All and developement of certain plants. This these regulations are, however, now abansuggestion is well worthy of the attention doned.: Rivero states that the annual conof the farmer. sumption of guano for the purposes of agriPerhaps the best and most practical me- culture amounts to 40,000 fanegas. The thod of fixing the ammoniacal salts of urine increase of crops obtained by the use of and night-soil, is to mix them with the guano is very remarkable. According to ashes of peat or coal. When the latter are the same authority, the crop of potatoes is employed, care must be taken to select such increased 45 times by means of it, and that as are of a porous, earthy consistence. The of maize 35 times. The manner of applyashes both of peat and coal contaiin in gene- ing the manure is singular. Thus in Arica, ral magnesia; hence their value as an in- where so much pepper (Capsicum baccatum) gredient of prepared night-soil. When is cultivated, each plant is manured three magnesia is not present, it will be necessary times: first upon the appearance of the roots, to add some magnesian limestone or Epsom second upon that of the leaves, and lastly salts. The night-soil should be mixed tho- upon the formation of the fruit. (Humboldt.) roughly with the ashes, and exposed to the From this it will be observed, that the Peair to dry. The disagreeable smell is thus ruvians follow the plan of the Chinese, in quickly removed, and a pulverulent manure manuring the plant rather than the soil. obtained, which can be applied to the fields The composition of guano points out how with facility. admirably it is fitted for a manure; for not Animal charcoal, which has served for only does it contain ammoniacal salts in the discoloration of sugar, possesses the pro- abundance, but also those inorganic constiperty of removing the offensive smell of tuents which are indispensable for the denight-soil, and is of itself an admirable ma- velopement of plants. nure. In cases where it can be procured The most recent analysis is that of V61cwith facility, it will be found to add to the kel, who found it to consist of efficacy of the latter. Urate of Ammonia.... 9.0 Oxalate of Ammonia... 10.6 GUANO. Oxalate of Lime... 7.0 Phosphate of Ammonia.. 6.0 The sterile soils of the South American Phosphate of Magnesia and Ammonia 26 coast are manured with a substance called Sulphate of Potash... 5.5 guano, consisting of urate of ammonia and Sulphate of Soda... 3.8 other ammoniacal salts, by the use of which Sal-ammoniac.,. 4.2 a luxuriant vegetation and the richest crops Phosphate of Lime 14.3 are obtained. Guano has lately been ir- Clay and Sand....7 ported in considerable quantity into Liverpool and several other English ports, and is * Much of the information regarding Guano now experimentally employed as a manure here given is extracted from a paper in Liebigr's by English agriculturists. A consideration Anealen, xxxvii. 3, 291. Of Its composition and mode of action can- t Reise um die Erde, B. i. S. 434. of its composition and mode of action can- t Garcilaso, Historia de' los ncas, vol. i. not, therefore, fail tro be acceptable. p. 134. (68 AGRICULTURAL CHEMISTRY. -67.7 requires manure containing nitrogen to be Organic substances not estimated, con-' imported from elsewhere, if it is desired to taining 12 per cent. of matter insolu- 32.3 produce a full crop. In large farms, the anble in water. Soluable Salts of Iron n in small quantity. Water,. J nual expenditure of nitrogen is completely - replaced by means of the pastures. 100.0 The only absolute loss of nitrogen, thereIt will be observed from the above analy- fore, is limited to the quantity which man sis, that urea does not enter into the compo- rries t him to his grave; but this at sition of guano. The uric acid of the ex-the utmost cannot amount to more than 3 crements must have been decomposed into lbs. for every individual, and is being coloxalic acid and ammonia. The soluble sub- lected during his whole life. Nor is this stances contained in guano amount to half quantity lost to plants, for it escapes into its weight. It is singular that we do not the atmosphere as ammonia during the pufind nitrates amongst the ingredients which trefaction and decay of the body. compose it. Guano possesses a urinous A high degree of culture requires an insmell, precisely similar to that perceived on creased supply of'manure. With the abunthe evaporation of urine. Theexperimentsdance of the manure, the produce in corn upon the efficacy of this manure in Eng- and cattle will augment, but must diminish land have not yet been sufficiently mult- with its deficiency. plied to enable us to judge whether or not From the preceding remarks it must be its virtues have been overrated. evident, th ththe greatest value should be atThe corn-fields in China receive no other tached t the liquid excrements of man and manure than human excrements. But we animals, when a manure is desired which cover our fields every year with the seeds of shall supply nitrogen to the soil. The weeds, which from their nature and form greatest part of a superabundant crop, or, pass undigested along with the excrements in other words, the increase of growth through animals, without being deprived of which is in our power, can be obtained extheir power of germination, and yet it is elusively by their means. considered surprising that where they have Vhen it is considered that with'every once flourished, they cannot again be ex- pound of ammonia which evaporates a loss pelled by all our endeavours': we think it of 60 lbs. of corn is sustained, and that very astonishing, while we really sow them with every pound of urine a pound of wheat ourselves every year. A famous botanist, might be produced, the indifference with attached to the Dutch embassy to China, which these liquid excrements are regarded could scarcely find a single plant on the is quite incomprehensible. In most places corn-fields of the Chinese, except the corn only the solid excrements impregnated with itself.''the liquid are used, and the dunghills conThe urine of horses contains less nitrooen taining them are protected neither from evaand phosphates than that of man. Accord- poration nor from rain. The solid exereing to Fourcroy and Vauquelin it contains ments contain the insoluble, the liquid all only five per cent. of solid matter, and in the soluble phosphates, and the latter conthat quantity only 0.7 of urea; whilst 100 tain likewiseall the potash which existed as parts of the urine of man contain more than organic salts in the plants consumed by the four times as much. animals. The urine of a cow is particularly rich Fresh bones, wool, hair, hoofs, and horn, in salts of potash; but according to Rouelle are manures containing nitrogen as well as and Brande, itis almost destitute of salts of phosphates, and are consequently fit to aid soda. The urine of swine contains a large the process of vegetable life. All animal quantity of the phosphate of magnesia and matter is fitted for the same purpose. ammonia; and hence itis that concretions Butchers' offal, such as the blood and intesof this salt are so frequently found in the tines of animals, form a most powerful maurinary bladders of these animals. nure. It is in general necessary to dilute It is evident that if we place the solid or such manure by admixture with other kinds liquid excrements of man or the liquid ex- less powerful in their action. crementS of animals on our land, in equal One hundred parts of dry bones contain proportion to the quantity of nitrogen re- from 32 to 33 per cent. of dry gelatine; now moved from it in the form of plants, the supposing this to contain the same quantity sun of this element in the soil must increase of nitrogen as animal glue, viz., 5.28 per every year; for to the quantity which we cent., then 100 parts of bones must be conthus supply, another portion is added from sidered as equivalent to 5250 parts of human fhe atmosphere. The nitrogen which we urine. export as corn and cattle, and which is thus Bones may be preserved unchanged for absorbed by large towns, serves only to be- thousands of years, in dry or even in moist nefit other farms, if we do not replace it. A soils, provided the excess of rain is preventfarm which possesses no pastures, and not ed; as is exemplified by the bones of anfields sufficient for the cultivation of fodder, tediluvian animals found in loam or gypsum, the interior parts being protected by * Ingenhouss on the Nutrition of Plants, page the exterior from the action of water. But 129 (German edition., they become warm when reduced to a filne OF MANURE. 69 powder,'and moistened bones generate heat phate of ammonia is not affected, unless the and enter into putrefaction; the gelatine heat has been carried too far. The liquor which they contain is decomposed, and its properly diluted has been found very advannitrogen converted into carbonateof ammo- tageous, even without the removal of the nia and other ammoniacal salts, which are ernpyreumatic matter. retained in a great measure ]by the powder Nitrate' of soda has lately engaged much itself. (Bones burnlt till quite white; and re- attention, and is supposed to exert its facently heated to redness, absorb 7.5 times vourable action upon vegetation by yielding their volume of pure ammoniacal gas.) nitrogen to those of their constituents which contain it. The experiments which have ARTIFICIAL MANURES. hitherto been instituted with this manure do WE have now examined the action of the not warrant us in concluding with positive animal or natural manures upon plants; but certainty that it is the nitrogen alone to it is evident that if artificial manures con- which it owes its efficacy, but they certainly tain the same constituents, they will exer- render this a plausible explanation of its cise a similar action upon the plants to virtues.'Thus Mr. Pusey, the late able which they are applied. We shall only president of the RoyalAgricultural Society, notice here one or two of those principally has shown, that the same effects are proemploved. duced by putrefied urine, soot, gas-liquorSince it has been ascertained that animal and nitrate of soda.s Now the three formanures act (as far as the formation of or- mer act by virtue of the ammonia which ganic matter is concerned) only by the am- enters into their composition. The usual rmonia which they contain, attention has effects produced by these and nitrate of soda been devoted by chemists to discover a are to increase the intensity of the green more economical means of presenting this colouring matter, to augment the quantity ammonia to plants. The water which dis- Pf straw, but to produce a light grain. Mr. tils from the retorts in the preparation of Hyettt has communicated the results of an coal gas is strongly charged with this alkali, analysis of two samples of wheat grown but is at the same time mixed with tar and under similar circumstances, one of which other empyreumatic impurities. It has been had been treated with nitre, the other not. customary to allow tile tarry matter to sub- The former contained 23'25 per cent. or side, and decant off the clear, supernatant gluten, and 1375 of albunen; the latter liquor. This liquor, being diluted to such only 19 per cent. of gluten, and 0-62 of ala degree as to be tasteless, is applied as a bumlen. Here the azotised matters appear manuure to the field, to have considerably increased in quantity. Now, the ammoniacal liquor of the gas- There is nothing opposed to the supposition works contains the ammonia in the form of that nitric acid may be.decomposed by carbonate and hydro-sulphate of ammonia plants, and its nitrogen assimilated. We (sulphuret of ammonium). Thelatter com- find that vegetables possess the power of pound is a deadly poison to vegetables, nor decomposing carbonic acid, and of appro-. can we conceive that by dilution its proper- priating its carbon for their own use. Now ties can be changed. The carbonate of this acid is infinitely more difficultto decomammonia is volatile, and escapes into the at- pose than nitric acid. But there are other mospher.e. To obviate this latter inconveni- circumstances which oppose the adoption ence and render it more transportable, it has of the view that nitrate of soda acts by virbeen proposed to convert the carbonate into tue of the nitrogen which enters into its the sulphate, by means of gyvpsum.* But composition. Were this the case, the acthis does not remove the hydro-sulphate. tion should be more uniform than it has A more simple and efficacious method is to' hitherto been found to be.. On some soils add a solution of sulphate of iron (the green the salt does not possess the' smallest influvitriol of the shops) to the liquor, until no ence; whilst on others it affords great benefurther precipitation ensues. Sulphuret fit We can only furnish anexplanatioq of and carbonate of iron are thus formed, and this seeming caprice by a reference to the the whole of the ammonia enters into com- chemical composition ot the soil upon which bination with the sulphuric acid, and forms it is applied. IS the advantages attending sulphate of ammonia. Care must be taken the application of nitrate of soda are due to to avoid too great an excess of sulphate of the alkaline base which it contains, then it iron; and the liquor thus prepared should is evident that this manure can be of small be freely exposed to the- air to p'romote the value on soils containing a quantity of alka-'oxidation. lies sufficient for the purposes of the plants The liquor still, however, contains em- grown upon them; whilst, on the other pyreumatic matters, which are injurious to hand, such as are deficient in these must explants. These may be removed by evapo- perience benefit through its means.t In rating the liquor to dryness, and heating the residue to incipient redness. By this means Journal of the Royal Agricultural Society they are rendered insoluble, and the sul- t Journal of the Royal Agricultural Society, vol. ii., p. 143. * Three Lectures on Agiiculture, by Dr. Dau- T General Sir Howard Elphinstone informs me beny, page 87. that he found carbonate of soda (soda ash) an es. 70 AGRICULTURAL CHEMISTR1Y certain cases in which nitrate of soda has ent families of plants are distinguished by failed, nitrate of potash (common saltpetre) containing certain acids, differing very muct has been very successful. Analyses of in composition; and further, that these acids wheat grown with nitrate of soda and nitrate do not exist in the juice in an isolated state, of potash would be of interest, in order to but generally in combination with certain determine whether a mutual substitution of alkaline or earthy bases. The juice of the their respective bases is effected. It is to be vine contains tartaric acid, that of the sorrel hoped that future experiments will throw oxalic acid. It is quite obvious that a pecumore light upon the action of this interest- liar action must be in operation in the oring manure, for theory cannot be satisfied ganism of the vine and sorrel, by means of with those already existing. It has been which the generation of tartaric and oxalic usual to employ a less quantity by weight acid is effected; and also that the same acof nitrate of potash than of nitrate of soda. tion must exist in all plants of the same This procedure seems rather empirical, for genus. A similar cause forces corn-plants unless sanctioned by experience, it would- to extract silicici acid from the soil. The a priori appear to be better to add the great- number of acids found in different plants is est quantity of that salt which possesses the very numerous, but the most common are highest equivalent: Now the equivalent of those which we have already mentioned; to nitrate of potash is considerably higher than which may be added acetic, malic, citric, that of nitrate of soda. aconitic, maleic, kinovic acids, &c. Charcoal in a state of powder must be When we observe that the proper acids considered as a very powerfulmeans of pro- of each family of plants are never absent rmoting the growth of plants on heavy soils, from it, we must admit that the plants beand particularly on such as consist of ar- longing to that family could not attain pergillaceous earth.+ fection, if the generation of their peculiar lngenhouss proposed dilute sulphuric acid acids were prevented. Hence, if the proas a means of increasing the fertility of a duction of tartaric acid in the vine were rensoil. Now, when this acid is sprinkled on dered impossible, it could not produce calcareous soils, gypsum (sulphate of lime) grapes, or in other words, would not fructify. is immediately formed, which of course Now the generation of organic acids is preprevents the necessity of manuring the soils vented in the vine, and, indeed, in all plants with this material. 100 parts of concen- which yield nourishment to men and anitrated sulphuric acid diluted with from 800 mals, when alkalies are absent from the soil'to 1000 parts of water, are equivalent to in which they grow. The organic acids in 176 parts of gypsum. plants are very rarely found in a free state; in general, they are in combination with potash, soda, lime, or magnesia. Thus, silicic acid is found as silicate of potash, SUPPLEMENTARY CHAPTER. acetic acid as acetate of potash or soda, oxalic acid as oxalate of potash, soda, or,)N THE CHEMICAL CONSTITUENTS OF SOILS. lime, tartaric acid as bitartrate of potash, &c. The potash, sodn, lime, and magnesia THE fertility of a soil is much influenced in these plants are, therefore, as indispensaby its physical properties, such as its poro- ble for their existence as the carbon from sity, colour, attraction for moisture, or state which their organic acids are produced. of disintegration. But independently of In order not to form an erroneous concluthese conditions, the fertility depends upon sion regarding the processes of vegetable the chemical constituents of which the soil nutrition, it must be admitted that plants reis composed. quire certain salts for the sustenance of their We have already shown, at considerable vital functions, the acids of which salts exist length, that those alkalies, earths, and phos- either in the soil (such as silicic or phosphates, which constitute the ashes of plants, phoric acids) or are generated from nutriare perfectly indispensable for their deve- ment derived from the atmosphere. Hence, lopement; and that plants cannot flourish if these salts are not contained in the soil, or upon soils from which these compounds are if the bases necessary for their production absent. The necessity of alkalies for the be absent, they cannot be formed, or in other vital processes of plants will be obvious, words, plants cannot grow in such a soil. when we consider that almost all the differ- The juice, fruit, and leaves of a plant can-... not attain maturity, if the constituents necessary for their formation are wanting, and cellent manure for his land. The crops obtained salts must be viewed as such. These salts by means of it presented the same general charac ters as those manured with nitrate of potash, and do not, however, occur simultaneously in exhibited a greater intensity of coloulr. If this is all plants. Thus, in saline plants, soda is found uniformly to be the case, it will very much the only alkali found; in corn plants, lime strengthen the supposition that the action of ni- and potash form constituents. Several contrate of soda is due to its alkaline constituent.- tain both soda and potash, some both potash ED.. * For much valuable information on the sub- and lime; whilst others contain potash and.1ect of manures, see " Agricultural Chemistry," magnesia. The acids vary in a similar vol. viii. of Sir H. Davy's collected Works. manner. Thus one plant may contain CONSTITUENTS OF SOILS. 71 phosphate of lime, a second, phosphate of gether lost to the English agriculturist, In magnesia, a third, an alkali combined with large towns it is either allowed to run into silicic acid, and a fourth, an alkali in corn- the rivers, or sink into the ground in such a bination with a vegetable acid. The re- manner as to be of no benefit to the vegetaspective quantities of the salts required by ble kingdom.X plants are very unequal. The aptitude of a The most important growth in England soil to produce one, but not another kind of is that of wheat; then of barley, oats, beans, plant, is due to the presence of a base which and turnips. Potatoes are only cultivated the former requires, and the absence of that, to a great extent in certain localities; rye, indispensable for the developemnent of the beet-root; and rape-seed, not very generally. latter. Upon the correct knowledge of the Lucerne is only known in a few districts, bases and salts requisite for the sustenance whilst red clover is found universally. Now, of each plant, and of the composition of the the selection of inorganic manures fbr these soil upon which it grows, depends the plants may be fixed upon by an examinawhole system of a rational theory of agri- tion of the composition of their ashes. Thus culture; and that knowledge alone can ex- wheat must be cultivated in a soil rich in plain the process of fallow, or furnish us silicate of potash. If this soil is formed with the most advantageous methods of af- from feldspar, mica, basalt, clinkstone, or fording plants their proper nourishment., indeed of any minerals which disintegrate Give-so says the rational theory-to one with facility, crops of wheat and barley may plant such substances as are necessary for be grown upon it for many centuries in sucits developement, but spare those, which are cession. But, in order to support an uninnot requisite, for.the production of other'terrupted succession, the annual disintegraplants that require them. tion must be sufficiently great to render It is the same with regard to these bases soluiLle a quantity of silicate of potash sufas it is with the water which is necessary ficient for the supply of a full crop of wheat for the roots of various plants. Thus, or'barley. If this is not the case, the soil whilst one plant flourishes luxuriantly in an must either be allowed to lie fallow from.arid soil, a second requires much moisture, time to time, or plants may be cultivated a third finds necessary this moisture at, the upon it which contain little silicate of potcpmmencement of its developement, and a ash, or the roots of which are enabled to fourth (such as potatoes) after the appear- penetrate deeper into the soil than corn ance of the blossom. It would be very er- plants in search of this salt. During this roneous to present the same quantity of interval of repose, the materials of the soil water to all plants indiscriminately. Yet disintegrate, and potash in a soluble state is this obvious principle is lost sight of in the liberated on the layers exposed to the action manuring of plants. An empirical system of the atmosphere. When this has taken of agriculture has administered the same place, rich crops of wheat may be again kind of manures to all plants; or when a expected. selection has been made, it was not based The alkaline phosphates, as well as the upon a knowledge of their peculiar charac- phosphates'of magnesia and lime, are neters or conlpositlon. cessary for the production of all corn-plarits.. The cost of labour in England has given Now, bones contain the latter, but none of rise to the production of much ingenuity in the former salts. These must, therefore, be the invention of machines, which have pro- furnished by means of. night-soil, or of duced improvements in the mode of appli- urine, a manure which is particularly rich cation of manures. In order to use these in them.* Wood ashes have been found with advantage, pulverulent manures are very usefill for wheat in calcareous soils; employed, instead of the common stable for these ashes contain both phosphate of manure, which is generally mixed with lime and silicate of potash. In like manner much straw. stable manure and night-soil render clayey The necessity for such forms of manure soils fertile, by furnishing the magnesia in naturally suggested the employment of bone which they are deficient. The ashes of all dust, dried dung, lime, ashes, &c. Now, kinds of herbs and decayed straw are capable although by these means the necessary of replacing wood ashes. phosphates are furnished to a soil, and solid A compost manure, which is adapted to animal excrements rendered unnecessary, furnish all the inorganic matters to wheat, they have led to the neglect of the liquid oats, and barley, may be made, by mixing excrements, that is, of the urine of men and equal parts of bone dust and a solution of animals, which is thus completely lost to silicate of potash (known as soluble glass in agriculture. For although the meadows commerce,)'allowing this mixture to dry in receive, during autumn and winter, when the air, and then adding 10 or 12 parts ot cattle are fed upon them, the solid and liquid gypsum, with 16 parts of common salt. excrements of these animals; yet the urine Such a compost would render unnecessary of man, into which all the nitrogenous con-.: stituents of animals are finally deposited, is completely lost to the fields. This most im- * It has been already stated that bran contains phosphate of soda and phosphate of magnesia, so portant of all manures. so properly estimated that it is useful as a manure where phosphates are in Flanders, Germany, and China, is alto-' desired.-ED. 72 AGRICULTURAL CHEMISTRY. the animal manures, which act by their in- Horn, wool, and hoofs of cattle, contain organic ingredients. According to Berthier, sulphur as a constituent, so that they will 100 parts of the ashes of wheat straw con- be found a valuable manure when adminis tain- tered with soluble phosphates, (with urine, Of matter soluble in water -. 9'0 for example.) Of matter insoluble in water o 81'0 Phosphate of magnesia and ammonia Novw 100 parts of the soluble matter con- forms the principal inorganic constituent of tain- the potato; salts of potash also exist in it, Carbonic acid. - ~ - a trace but in very limited quantity. Now the soil Sulphuric acid - *2' 0 is rendered unfitted for its cultivation, even Muriatic acid -. 130 though the herb be returned to it after the Silica -... 350 removal of the crop, unless some means are Potash and Soda - - - 50.0 adopted to replace the phosphate of magnesia removed in the bulbous roots. This is best 100 0 effected by mixtures of night-soil with bran, 100 parts of the insoluble matter contain- magnesian limestone, or the ashes of certainl Carbonic acid. 0 kinds of coal..' I applied to a field of potaPhosphoric acid. v 12 toes manure, consisting of night-soil and Silica... 75.0 Linie - -. 58 sulphate of magnesia, (Epsom salts,) and Oxide of Iron and Charcoal - 100 obtained a remarkably large crop, The maPotash: - 8-0 nure was prepared by adding a quantity of sulphate of magnesia to a mixture of urine 100.0 and faeces, and mixing the whole with the The silicate of potash employed in the ashes of coal or vegetable mould, till it acpreparation of the compost described above quired the consistence of a thick paste, must not deliquesce on exposure to the air, which was thus dried' by exposure to the but must give a gelatinous consistence to sun. the water in which it is dissolved, and dry It has been formerly mentioned, that the to a white powder by exposure. It is only secondary and tertiary limestones contain attractive of moisture when an excess of potash: marl, and the calcareous minerals potash is'present, which is apt to exert an used for the preparation of hydraulic mortar, injurious influence upon the tender roots of may be particularly specified. These have plants. In those cases where silicate of been found to form excellent manures for potash cannot be procured, a sufficiency of heavy clayey soils, particularly for such as wood ashes will supply its place.~ disintegrate with difficulty. They are most All culinary vegetables, but particularly efficacious when burnt, but can only be apthe.cruciferoe, such as mustard, (sinapis plied in this state after harvest, and ought alba and nig-ra,) contain sulphur in notable to be ploughed into the soil as quickly as quantity. The same is the case with turnips, possible.. By the action of lime upon clay, the different varieties of rape, cabbage, the potash contained in the latter is rendered celery, and red clover. These plants thrive soluble. This may easily be shown by mixbest in soils containing sulphates; hence if ing one part of marl with half its weight of these salts do not form natural constituents burned lime, adding water, and setting aside of the soil, they must be introduced as ma- the mixture to repose for some time. Even nure. Sulphate of ammonia is the best after a. space of 24 hours, an appreciable salt for this purpose. It is most easily pro- quantity of potash may be detected in the cured by the addition of gypsum or sulphate water.* of iront (green vitriol) to putrefied urine. A most striking proof of the influence of potash upon vegetation has been furnished * In some parts of the grand-duchy of Hesse, by the investigations of the " administration"s where wood is scarce and dear, it is customary of tobacco in Paris. For many years accufor the common people to club together and build rate analyses of the ashes of various sorts baking ovens, which are heated with straw instead of tobacco have been executed, by the orders of wood. The ashes of this straw are carefully of the " administration;" and it has been collected and sold every year at very high prices. these, that the value The farmers there have found by experience thatound, as the result of these, that the value the ashes of straw form the very best manure for of the tobacco stands in a certain relation to wheat; although it exerts no influence on the growth of fallow-crops (potatoes or the legumi * One of the causes of the advantages produced, nose, for example.) The stem of -wheat grown by subsoil ploughing' is, that it exposes the soil to in this way possesses an uncommon'strength. the disintegrating influences of the atmosphere. Thle cause of the favourable action of these ashes Hence it is that the subsoil plough is so beneficial will be apparent, when it is considered that all in siliceous soils, and exerts no apparent effect corn-plants require silicate of potash; and that upon those which contain much clay. The former the ashes of straw consist almost entirely of this disintegrate and liberate their potash both with compound.-ED. facility and rapidity; whilst the disintegration of t If sulphate of iron be employed, it ought not the latter proceeds with slowness, and no appre. to be added in great excess, and the urine must ciable'effects are produced. (See Journal of the be exposed to the air for some time after, for the Agricultural Society, vol. ii., p. 27.) It is proba. purpose of converting the iron into the peroxide. ble, however, that if the land received a dressing A salt of the protoxide of iron is injurious to of lime after subsoil ploughing, the effects would vegetation. be produced more rapidly.-ED. COMPOSITION OF SOILS. 73 the quantity of potash contained in the markable for producing uncommonly fine ashes. By this means a mode was furnished red clover when manured with, gypsum. of' distinguishing the different soils upon (B) is an analysis of the subsoil..100 parts which the tobacco under examination had contain:been cultivated, as well as the peculiar class (A) (B) to which it belonged. Another striking fact Silica, with fine siliceous sand - 91'331 93 883 was also disclosed through these analyses. Alumina - - - 1344 1'944 Certain celebrated kinds of American tobacco Peroxide of iron, with a little prowere found gradually to yield a smaller Peroxide of manganese - - 0862 0.320 quantity of ashes, and their value dimi-Magnesia andsilica, in combinanished in the same proportion. For this in-.tion with suiphuric acid and formation I am indebted to M. Pelouze, pro- humus - - - 0800 0'720 fessor of the Polytechnic School in Paris. Magnesia, with silica and humic There are certain plants which contain acid combied - 040 0340 Potash,in combination with silica 0'156 0'105 eitlher no potash, or mere traces of it. Such Soda, principally in combination the poppy, (p.p ave; lomnf[~rttm,) which Soda, principally in combination are the poppy, (papaver somniferutn,) which withsilica, and a little'as comgenerates in its organism a vegetable alka- mon salt - * - 0'066 0'060 loid, Indian corn, (zea mays,) and helianthnts Phosphoric acid - 0'098 0'190 tuberosus.w For plants such ds these the pot- Sulphuric acid in combinat.on ash in the soil is of no use, and farmers are with lime -. 0111 0'012 well aware that they can be cultivated with- Humus (ith traces of azotised 002 00 out rotation on the same soil, particularly matter -. - 4'100 0'184 when the herbs and straw, or their ashes, are returned to the soil after the reaping of 100 000 the crop. An inspection of the above analyses will One cause of the favourable action of the show that the soil contains a very small pronitrates of soda and potash must doubtless portion of salts of sulphuric acid-a circumbe, that through their agency the alkalies stance which accounts for the favourable2 which are deficient in a soil are furnished to action of gypsum upon it. it. Thus it has been found that'in soils de- 2. The surface-soil (A) is a fine-grained ficient in potash, the nitrates of soda or pot- loamy soil from Gandersheim, distinguished ash have been very advantageous; whilst for the remarkably large crops of beans, those, on the other hand, which contain a peas, tares, &c., which it produces when sufficiency of alkalies, have experienced no manured with gypsum. (B) is the analysis beneficial effects through their means, In of the subsoil. 100 parts contain:the application of manures to soils we should (A) (B) be guided by the general composition of the Silica, with fine siliceous sand - 90-221 92'324 ashes of plants, whilst the manure applied Alumina - - 2'106 2'262 to a particular plant ought to be'selected Peroxide and protoxide of iron - 3'951 2'914 with reference to the substances which it Peroxide of manganese - 0960 2960 demands for its nourishment. In general, a Lime. principally combined with b. a t.' ^ phosphoric acid and humus - 0 539 0 532 manure should contain a large quantity of Magnesia, with silicate of pot0 alkaline salts, a considerable proportion of ash, &c. - - 0730 o0'340 phosphate of magnesia, and a smaller pro- Potash.. - 0'067 0'304 portion of' phosphate of lime; azotised ma- Soda 0-010 a trace nure and ammoniacal salts cannot be too Phosphoric acid 0367 0122 Sulphuric acid (in gypsum) - a trace 0'010 frequently employed. Chlorine (in common salt) 0100 0004 In the following part of this chapter I Humus and azotised matter - 0.900 - shall describe a number of analyses of soils Loss - - - 0'140 0'228 executed by Sprengel, together with obser-ooo ooooo vations on their sterility and fertility, as 100 stated by that distinguished agriculturist. The analysis of this soil shows, that, with Itis unnecessary to describe the modus ope- the exception of gypsum, every ingredient randi used in the analyses of these soils, for is present which is requisite for the nourishthis kind of research will never be made by ment of leguminous plants. Hence it is farmers, who must apply to the professional that gypsum exerts such a favourable inffuchemist, if they wish for information regard- ence upon it. - ing the composition of their soils. 3. Surface-soil (A) a strong loamy sand, Under the term suiface-soil, we mean that from Brunswick. (B) the analysis of the portion of soil which is on the surface; subsoil, 100 parts contain:whilst: by subsoil we mean that which is be- (A) (B) low the former, and out of the reach of the, Silica, with coarse siliceous sand 95'698 96,880 ordinary plough. Alumina 0504 0p890 Peroxide and protoxide of iron - 2496 1'496 Peroxide of manganese- - a trace a trace CHEMICAL COMPOSITION OF CERTAIN SOILS, Lime - - 0038 0.019 ACCORDINGt TO ANALYSIS. Magnesia - 0'147 0'260 Potash and soda, the glreatest 1. Surface-soil (A) a good loamy soil, part in combination with silica 0'090 0'079 from the vicinity of Gandersheim. It is re- Phosphate of iron - ~ 0164 0110 10 G -74 AGRICULTURAL CHEMISTRY. (A) (B) (A) (B) Sulphuric acid (in gypsum) - 0007 a trace Silica, with fine siliceous sand - 94'998 96.490 Chlorine (in common salt) - 0'010 a trace Alumina - - - 0610 1'083 -Iumus - - - 0846 0'226 Protoxide and peroxide of iron 1'080 1.472 ____. Peroxide of manganese - 0.268 0'400:100 000 100o000 Lime, in combination with silica 0'141 0.182 Magnesia, idem - - 0'208 0'205 This soil was much improved by manur- Potash, ide - - - 0050 0070 Soda idem - - 0'044 0'050 ing with lime and ashes. It was then found Phosphate of iron - 0086 0'030 well fitted for clover, beans, and peas. Gypsum 0. -0041 0'005 4. Surface-soil (A) a loamy sand, from Common salt - - - 0004 0'003 the environs of Brunswick. (B) analysis Humus soluble in alkalies'- 0'400 0010 of the subsoil at the depth of 3 feet. 100 Humus accompanied by azotised parts contain: - matter - - - 2.070... Resinous matter. a trace (A) (B) - 0 Silica and fine siliceous sand - 94'724 97'340 Alumina - - - 1'638 0.806 This soil is by no means remarkable for Protoxide and peroxide of iron its sterility, but is decidedly improved by Lime - 1'028 0'296 manuring with burned ferruginous loam. Magnesia - a trace 0'095 It is, however, rendered still better by the Potash and soda 0'077 0'112 use of burned marl —a manure which is Phosphoric acid - 0'024 0'015 rich in iron, potash, gypsum, and phosphate Gypsum. - 0010 a trace of lime. The marl does not exert so favourChlorine of the salt - 0207 a trace able an,~ction when applied in its natural state; but the heat liberates the potash from loo0ooo- 100000 the insoluble compound which it forms with silica. This soil produces luxuriant crops of lu- 7. Surface-soil (A) a loamy sand, from cerne and sainfoin, as well; as of all other Brunswick. (B) analysis of the subsoil at plants the roots of which penetrate deeply a depth of 1 feet. 100 parts contain:into the ground. The reason is apparent. (A) (B) The subsoil contains magnesia, which is Silica, with fine siliceous sand 92'980 96'414 wanting in the surface-soil. Alumina - 0'820 1'000 5. Surface-soil (A) a loamy sand, from Protoxide and peroxide of iron 1'666 1'370 the environs of Brunswick. (B) analysis Peroxide of manganese - 0.188 0240 Lime, combined with silica - 0'748 0'364 of the subsoil at a depth of 2 feet. 10OOparts Magnesia, idem 0168 0 160 contain:- Potash, idem. - - 0'065 0'045 Soda, idem - - 0130 0:082 Phosphate of iron - - 0246 0-043 Silica, with coarse siliceous sand 95'843 95.190 Sulphuric acid contained in gyp. Alumina - 0'600 1'600 sum... a trace 0'005 Protoxide and peroxide of iron 1'800 2'200 Chlorine - a trace 000G7 Peroxide of manganese - a trace a trace Humus soluble in alkalies. 0'764 0270 Lime, in combination with silica 0'038 0.455 Humus with azotised organic Magnesia in do. do. 0'006 0'160 H s a o 225 Potash and soda - 0 005 000 remains - 225 Phosphate of iron - - 0198 0'400 100-000 100-000 Sulphuric acid - - 0'002 a trace Chlorine - - 00 0'001 The soil when manured with gypsum is Humus soluble in alkalies - 1'000. Humus insoluble in alkalies 01000 very favourable to the production of leguHumus insoluble in alkalies 0'502 - minous plants and. red clover. But ii is 100000 100000 very remarkable, on account of the rust which always attacks the corn plants which This soil is characterised by its great may be grown upon it. This rust and milsterility. White clover could not be made dew (uredo linearis, puccinia graminis) is a to grow upon it. The obvious cause of its disease which attacks the stem and leaves, poverty is a deficiency of lime, magnesia, and is quite different from the brand (uredo potash, and gypsum; for we find that the glumarum) which appears on the seeds and fertility of the soil was much increased by organs of reproduction. Rust is most fremanuring it with marl. The white clover, quently detected on plants growing on soils which formerly had refused to grow on this which contain bog-ore or-turf-iron ore. Acsoil, now grew upon it with'much luxuri-: cording to Sprengel,rust contains phosphate ance. The aridity of the soil could not have of iron, to which this chemist ascribes the been the cause of its sterility, for the stiff origin of the disease. It is very possible that nature of the subsoil on which it rested pre. other causes may operate in the production vented a deficiency of moisture. of similar diseases. 6. Surface-soil (A) a loamy land from the 8. Soil, a fine-grained loamy marl, from environs of Brunswick. (B) the analysis the vicinity of Schoningen. It produces of the' subsoil, at a depth of 2 feet. 100 corn, which is, however, very liable to parts contain: — blight. -100 parts contain: COMPOSITION OF SOILS. T Silica, with siliceous sand - 93'870 they should, for the roots of the hops peneAlumina - - - 1'248 trate 8 or 10 feet deep into the soil, and search Protoxide and peroxide of iron - - 1-418 l Peroxide of manganese - 0360 out the materials fitted to nourish the plants. Lime(principally carbonate) -. 0'546 Hence it is that hops thrive well on soils Magnesia, idem -. 0560 comparatively poor in their proper ingrediPotash, with silica - - 0050 ents. The same is the case with all plants Soda with silica -. 0'040 of a similar nature, the roots of which posPhosphate of iron - - 0246 sess a tendency to extend in search of od; Sulphuric acid with lime - - 0027 sess a tendency to extend n search offod Carbonic acid, with lime and magnesia - 1145 we see this particularly in lucerne and sainHumus soluble in alkalies - - 0400 foin. Humus... 0090 SOILS OF HEATHS. o100-000 It will be observed that a considerable 11. Soil of a heath converted into arable quantity of phosphate of iron is contained land, in the vicinity of Brunswick. It is in this soil, and the corn which grows upon naturally sterile, but produces good crops it is, as in the former case, disposei to rust. when manured with lime, marl, cow-dung, 9. Surface-soil (A) a loamy soil, from or the ashes of the heaths which grow Brunswick, remarkable on account of -pro- upon it. ducing buck-wheat, which is exceedingly Silica, and coarse siliceous sand - 71.504 poor in the grain. (B) analysis of the sub- Alumina - - - 0.780 soil at a depth of I'foot. 100 parts con- Protoxide and peroxide of iron, principally ~~~~~~tamin:~~ - combined with humus - - 0.420 tain:-_ Peroxide of manganese, idem - - 0.220 (A) (B) Lime, idems. 0.134 Silica, with coarse siliceous sand 95,114 92458 Magnesia, idem - - - - 0.032 Alumina 1'080 2'530 Potash and soda, principally as silicates - 0.058 Protoxide and peroxide of iron 1'900 2-502 Phosphoric acid, (principally as phosphate Protoxide and peroxide of man. of iron). - - - 0.115 ganese - - - 0320 0-920 Sulphuric acid (in gypsum) - - - 0.018 Lime, in combination with silica 0'380 0'710 Chlorine (in common salt) -- - 0.014 Magnesia, idem - - 0'300 0'551 Humus soluble in alkalies - - - 9.820 Potash, with silica - 0020 0.120 Humus, with vegetable remains - 14.975 Soda.- 0.004 0'034 Resinous matters - - - 1.910 Phosphate of iron. - 0052 0175 Suiphuric acid with lime - 0'006 a trace 100.000 Chlorine (in common salt) 0'005 a trace Humus soluble in alkalies e 0619. Ashes of the soil of the heath, before beHumus - 0-200. ing converted into arable land:- - Silica, with siliceous sand - - - 92.641 100'000 100-000 Alumina - - - 1.352 the land with wood ashes Oxides of iron and manganese - - 2.324 By manuring ad., Lime, in combination with sulphuric and the soil is enabled to produce buck-wheat, phosphoric acids - - - - 0.929 with rich grain; the leguminous plants also Magnesia, combined with sulphuric acid - 0.283 thrive luxuriantly upon it. This increased Potash and soda (principally as sulphates fertility is due to the ashes, by means of and phosphates.. - - 0.564 which both potash and phosphates are sup- Phosphoric acid, combined with lime 0.250 plied to th land. Sulhuric acid, with potash, soda and lime 1.620 10. Subsoil of a loamy, sandy soil, fromChoiencmonsl. 003 Brunswick. It is remarkable for having 100.000 produced excellent crops of' hops for a long 12. Surface-soil of a fine-grained loam, Series- of'years. 100 parts, by weight, con- from the vicinity of Brunswick. It is r-esist of: markable from the circumstance, that not a Silica, with siliceous sand - 95.660 single year passes in which corn plants are Alumina -.. - 1.586 cultivated upon it without the stem of the Protxideandpetoideo irn 11616plants being attacked by rust. Even the Peroxide of m. nganese.. 0.240 lime, in combination with silica - 0.083 grain is covered with a yellow'rust, and is Magnesia. - - - 080much shrunk. 100, parits of the soil conPotdsh - o- -0.3 tatn Soda - 0.22-0 Silica and fine siliceous sand - - 87.859 Phosphoric acid - 0.039 Auia - - - - -2.652 Sulphuric acid - - - 0.003 Peroxide of iron with a large proportion of -Chlorine - -a trace protoxide. 5.132' Humus soluble in alktalies - 0.080 Protoxide and peroxide of manganese -0.840 Humus - - - -.0.360 Lime principally combined with silica - 1.459 - Magnesia, idems.0.280 100.000 Potash and soda, idem - 0.090 A~tnougth the hops contain a large quan- Phosphoric acid in combination with iron 0.505 tity of -potash., soda, phosphoric acid, sul- Sulphuric acid incmiain.ihlm 0.06 phuric acid, lime, and magnesia, yet we do Chlorine in common salt -. -00- not find that these exist in the soil in superabundant quantity. Nor is it necessary that 1oo.ooo 76 AGRICULTURAL CHEMISTRY. This soil does not suffer from want of it, in such a manner that they were not exdrainage: it is well exposed to the sun, is hibited by analysis. in an elevated situation, and in a good state Oats and barley were sown on this land of cultivation. In order to ascertain whether the second year after being reclaimed, and the rust was due to the constituents of the both suffered much from rust, although difsoil, (phosphate of iron?) or to certain for- ferent parts of the soil were manured with tuitous circumstances unconnected with marl, lime and peat-ashes; whilst other portheir operation, a portion of the land was tions were left without manure. In the first removed to another locality, and made into year, all the different parts'of the field proan artificial soil of fifteen inches in depth. duced potatoes, but they succeeded best in Upon this barley and wheat were sown;but those divisions which had been manured it was found, as in the former case, that the with peat-ashes, lime and marl. In the plants were attacked by rust, whilst barley second year, oats mixed with a little barley growing on the land surrounding this soil were sown upon the soil; and the straw was not at all affected by the disease. From was found to be strongest on the parts treated this experiment it follows, that certain con- with peat-ashes, lime, marl, and ashes of stituents in the soil favour the developement wood. Red clover was sown on the third of rust. year; it appeared in best condition on those 1.3. Soil of a heath, which had been portions of' the soil manured with marl and brought into cultivation in the vicinity of lime. Upon the divisions of the field which Brunswick. The analysis was made before had been left without manure, as well as on any kind of crops had been grown upon it. those manured with bone-dust, potash, amCorn-plants were first reared upon the new monia and common salt, the clover scarcely soil, but were found to be attacked by the appeared above ground. The divisions of rust, even on those parts which had been the field, which had been manured in the manured respectively with lime, marl, pot- first year with peat-ashes, ammonia, and ash, wood ashes, bone-dust, ashes of the ashes of wood, were sown with buckwheat' heath plant, common salt and ammonia. after the removal of the first crop of clover. 100 parts contain:- The buckwheat succeeded very well on all Silica with coarse siliceous sand' 51'337 the divisions, yet a marked difference was Alumina 0 528 perceptible in favour of the portion treated Protoxide and peroxide of iron in combina- with ammonia. These experiments show tion with phosphoric and humic acids 0 398 us, that a dressing of lime did not completely Protoxide and peroxide of manganese 0- 005 remove from the soil its tendency to impart Lime in combination with humus - 0230 Magnesia idem. - * 0'040 rust to the plants grown upon it. NeverPotash and soda - 0- 010 theless it is highly probable, that:as soon as'Phosphoric acid.. - 0 066 the protoxide of iron became converted into Sulphuric acid,' - - 0'02 the peroxide by exposure to the atmosphere, Chlorine - - - 0 014 lime would' possess more power in decomHulmus soluble in alkalies - 13'210 R{tsinous matters - - - 2'040 posing the phosphate of iron. R-sinous matters 2 040 Coal of humus and' water - 32'100 14. Subsoil of a loamy soil in the vicinity of Brunswick. It-is remarkable from the 100'000 circumstance that sainfoin cannot be cultivated upon it more than two or three years The next analysis represents the soil after in succession. The portion analysed was being burnt. I00 parts by weight of the soil taken from a depth of five feet. 100 parts left after ignition only 50 parts. 100 parts contained:of these ashes consisted of: Silica with very fine siliceous sand 90'035 Silica and siliceous sand - - 95'204 Alumina. - 1'976 Alumina - - -: - 1640 Peroxide of iron - -. 4'700 Peroxide of iron - - - 1 344 Protoxide of iron - 1'115 Peroxide of manganese - - 0'80 Protoxide and peroxide of manganese 0240 Lime in, combination with sulphuric acid 0'544 Lime 0 022 Magnesia combined with silica -'0'465 Magnesia 0115 Potash and soda - 0'052 Potash and soda 0 - 300 Phosphoric acid (principally as phosphate of Phosphoric acid, combined with iron 0098 iron......0'330 Sulphuric acid (the greatest part in combinaSulphuric acid - - - - 0'322 tion with protoxide of iron) - 1399 Chlorine. 0019 Chlorine. - - a trace 100ooooo-000 100.000 By comparing this analysis with the one Now the results of the analysis give a suffmwhich has preceded' it, an increase in cer- cient account of the failure of the sainfoin. tain of the constituents is observed, particu- The soil contains above one per cent. of larly with respect to the sulphuric acid, pot- sulphate of protoxide of iron (green vitriol ash, soda, magnesia, oxide of iron, oxide of of commerce,) a salt which exerts a poisonmanganese, and alumina. From this it fol- ous action upon plants. Lime is not prelows, that the humus. or in other words, the sent in quantity sufficient to decompose this vegetable remains, must have contained a salt. Hence it is that sainfoin will not thrive quantity of these substances confined within on this soil, nor indeed lucerne, or any other CONSTITUENTS OF SOILS. 77 of the plants with deep roots. The evil can- consisting principally of sand, and eminently not be obviated by any methods sufficiently remarked for its sterility. It was, however, economical for the farmer, because the soil much improved by manuring it with marl cannot be mixed with lime at a depth of five which contained 24 per cent. of lime, toor six feet. For many years experiments gether with magnesia, manganese, potash, have been made in vain, in order to adapt soda, gypsum, and common salt. 100 parts this soil for sainfoin and lucerne, and much of the soil contained:expense incurred, which could all have been Silica and siliceous sand - - - 958t11 saved, had the soil been previously analysed. Alumina - - - 0'600 This example affords a most convincing Protoxide and peroxide of iron - - 1800 proof of the importance of chemical know- Peroxide of manganese - a trace ledge to an agriculturist. Lime in combination with silica 0'038 15. Surface soil (A) of a sandy loam in Magnesia, ide. - 0006 the vicinity of Brunswick, celebrated for its Soda - 0003 beautiful crops of clover', rye, potatoes, and Phosphoric acid combined with iron - 01!98 barley. The clover must, however, always Sulphuric acid - 0002 be manured with gypsum. (B) is an ana- Chlorine - - - 0006 lysis of the subsoil at the depth of 1 foot. Humus - - 1504 100 parts contain: 100'000 (A) (B) Here another'proof is presented, that -a Silica with coarse siliceous sand 94.274 95'146 soil may be very rich in humus and yet be Alumina 1.560 1'416 Peroxide of iron with a little very poor as regards fertility. By means of phosphoric acid... 2'496 2'528 the. marl, the inorganic ingredients of the Peroxide of manganese - 0240 0'320 plants are furnished to the soil, which conLime - - - - 0'400 0297 tains them in very small quantity. Magnesia - -: 0230 0'221 18. The soil of a very fertile loam from Sulphuric acid soda 0102 0060 the vicinity of Walkenried. 100 parts conSulphuric acid - 0'039 0'012 Chlorine - - 0'005 a trace tan H-umus soluble in alkaline car- Silica, with coarse-grained silicious sand 88'456 bonates -. 0'444 ~ Alumina 0'650 Humus - - 0'210.. Peroxide and protoxide of iron, accompanied by much magnetic iron sand -' 5'608 100,000 100,000 Peroxide of manganese - - 0560 The best property of this soil is, that its Carbonate of lime 063 Carbonate of magnesia -.. 1688 inferior layers are nearly of the same com- Potash combined with sia 1-6&8 Potash combined with silica 040 position as the superior, as far as the inor- Soda combined with silica. - 0012 ganic constituents are concerned. It is a Phosphate of lime -. 0'035 soil upon which the plants mentioned above Sulphate of lime.'- e a trace will seldom fail; and as it possesses a very Common salt - -'5 good mixture to the depth of four or five Humus soluble in alkalies - - 0 550 fegood mixtue tou, dbthe s, poducepo uroveHumus with several azotised organic refeet, it would, doubtless, produce'lucerne mains -... 1333 also. 16. Surface-soil (A) of a sandy loam in' 100o000 the vicinity of Brunswick. It produces ex- Gypsum acts most excellently upon this cellent crops of oats and clover, when the land. The soils in the southern range of latter is manured with gypsum. (B) Ana- the Harz mountains are particularly relysis of the subsoil taken from a depth of 1 marked for containing more manesia than P 2 marked for containing more magnesia than foot. ~100 parts contain:-, lime. Even the different varieties of marl (A) (B) contain a considerable quantity of magnesia. Silica anid siliceous sand - 94 430 89'660 Thus, in a specimen of marl obtained from PeroxAlumina of iron w a. 1474 0 980 the vicinity of Walkenried, I obtained 55~ Peroxide of iron with a little phosphoric acid - 2a370 7616 per cent. carbonate of lime, and 301 per Peroxide of manganese - a trace a trace cent. carbonate of magnesia; in another 41 Lime, principally combined with per cent. lime, and 11 per cent. magnesia; silica - - 0680 0'954 and in a third, 47~ per cent. lime, and 131 Magnesia, idem - - 0290 0'520 per cent. magnesia. Most of these soils PSoda W.I. 1o 00150 contain also a-1 per cent. of gypsum, Soda 0'010 Sulphuric acid -. e a trace a trace and e —1 per cent. phosphate of lime, and Chlorine -. 0'015 a trace are, therefore, well fitted for manuring other Humus - - 0'541 0'120 lands. - 19. Subsoil of a loam from a depth of lI 100'000 100 000 foot. It occurs in the vicinity of Brunswick. Both the surface and the sub-soil contain The surface-soil is remarkable on account only traces of sulphuric acid. Hence the of producing beautiful red clover on being application of gypsum is attended with great manured with gypsum; although the so;i benefit. Without doubt, marl and lime would itself contains only traces of lime, magnesia, be found of essential service. potash, and phosphoric acid. 100 parts of 17. Soil from the environs of Brunswick, I the subsoil contained:G 2 78 ~ ~AGRICULTURAL CIHEMISTRY. Silica and coarse siliceous sand. 88'980 1 Peroxide of manganese - a trace Alumina - - - 2'240 Lime, in combination with silica, sulphuric Protoxide and peroxide of iron 3'840 acid, and humus - - 1'653 Peroxide of manganese -. a trace Magnesia, in combination with silica 0'036 Carbonate of lime -. 2'720 Potash, principally in combination with silica 0'038 Carbonate of magnesia - 0'600 Soda - a trace Potash and soda. 0095 Phosphoric acid - - - - a trace Phosphate of lime. - 1.510 Sulphuric acid. - 0051 Sulphate of lime. - a trace Chlorine -. a trace Common salt D. 0'015 Humus, soluble in alkaline carbonates 2'084 Humus - 1'900 100'000 Resinous matter - - - 0420 At a greater depth than the subsoil of 100000 which the analysis is here given, the soil passes into mar], which contains 20~ per This soil contains a large quantity of cent. of carbonate of lime. The sulphuric protoxide of iron, which, together with a acid deficient in the soil was supplied by deficiency of phosphoric acid, is the cause means of the gypsum. of its sterility. But when this land was manured with the ashes of peat, it was SOILS IN THE KIINGDOM OF HANOVER. rendered much more fertile. The ashes used for this purpose were found to contain 20. (A) Analysis of a barren heath-soil in 100 parts: from Aurich in Ostfriesland; (B) a sandy soil containing much humus but also sterile; Silica, with siliceou sand 9 Alumina 1'859 (C) a sandy soil possessing the same cha- Peroxide and protoxide of iron, with a litracters as B. 100 parts contained: tie phosphoric acid - - 1'120 (A) (B) (C' Peroxide of manganese -. 0160 Silica and coarse siliceous Lime 0 112 sand - - 95'778 85'973 96'721Magnesia - 0141 Alumina 0320 0'320 0'370 Potash 0.093 Protoxide and peroxide of Soda 0.007 iron 0- 0400 0'440 0-480 Sulphuric acid 0152 Peroxide of manganese a trace a trace a traceChlorine - - 0004 Lime - 0'286 0.160 0'005' 100'000 Magnesia - - 0060 0'240 0080 100000 Soda 0036 0'012 0'036 The ashes, on exposure to the air, abPotash - a trace a trace a trace sorbed ammonia. Phosphoric acid. a trace a trace a trace Sulphuric acid - a trace a trace a trace 23. Analysis of a very fertile loamy soil Chlorine in common salt 0'052 0'019 0'058 from Gfttingen. It is very rich in humus, Humus - 0 -768 0636 0800 and produces beautiful crops of peas, beans, Vegetable remains 2'300 8'200 1-450 lucerne, and beet. The sieve separates from - 100000 100'000 i00 000 100 parts of the soil:211. Analysis of the clayey subsoil of a Small stones, principally limestone - 1 2i..Analysis of the clayey subsoil of a Qaarzy sand, with a little magnetic iron sand 15 moor, which, after being burned, is used as Earthy part.. 84 a manure to the above soils, A, B, C. 100 parts contain:- 100 Silica and siliceous sand. 87'219 100 parts of the soil, freed from stones, Alumina - 4200 consists of Peroxide of iron with a little phosphoric acid 5 200 Peroxide of manganese 0- -310 Silica, and fine siliceous sand - 83'298 Lime - - 0320 Alumina, combined with silica -.1413 Magnesia - - 0 380 Alumina! partly in combination with humus 3'715 Potash principally combined with silica 0-130 Peroxide and protoxide of iron, in combiSoda principally combined with silica - 0-274 nation with silica -0.724 Sulphuria acid combined with lime, magne- Peroxide and protoxide of iron, partly free sia, and potash -. 0965 and partly in combination with humus 2'244 Chlorine - - 0'002 Peroxide and protoxide of manganese 0.280 Humus -. 1000 Lime, with coal of humus, sulphur, and phosphoric acid - 1814 100o000 Magnesia, combined with silica. 0'422 Magnesia, combined-with humus - 0'400 By comparing this analysis with that of Potash - - - - 0'003 the three soils which have preceded, it will Soda a.. - - 0'001 be observed that this subsoil is fitted to im- Phosphoric acid.. - 0166 part to them those mineral ingredients in Sulphuric acid 0-069 Chlorine 00- - - 002 which they are deficient. which they are deficient. Carbonic acid (as carbonate of lime) 0'440 22. Surface soil of a barren heath in the Humus, soluble in alkalies. 0789 vicinity of Walsrode in Luneberg. 100 Humus, with a little water.. 3250 parts by weight contai.N Nitrogenous matter -. 0'960 Resinous matter a trace Silica and siliceous sand -. - 92'216 Alumina - - - - 0'266 Peroxide of iron - - - 0942 Protoxide of iron - 0'394 The subsoil is of the same composition as CONSTITUENTS OF SOILS. 79 the surface, with this difference only, that it salt, lime, magnesia, and saltpetre. It aftercontains more potash, sodt, and chlorine, wards reaches the soil, and manures it with and is interspersed with fragments of fresh- these.ingredients. It is only in this manner water shells. Hence it is that the soil pro- that we are enabled to explain the fertility duces the deep-rooted plants in such luxu- of this soil; for, reasoning from its chemical riance. composition, we would be induced, d priori, 24. Soil of a sterile moor, which had to suppose that it would be barren. At the been burned three times, and upon which base of this hill, certain portions of the land buckwheat had been cultivated. 100 parts are covered with calcareous tuff, containing contained the above salts: a fact which proves that sthe water which penetrates through the soil Humus, soluble in alkalies - 9'250them in solution. The Vegetable remains, charcoal, quarzy m sand, and earthy particles - 90)750 large proportion of humus exhibited by the - analysis depends upon the nature of the 100'000 manure to which it was treated. 100 partsby weight left, afterigniton, 10 26. Analysis of a heavy alluvial soil, of0 parshb~es. g10 left, after;ignition, 10 from Norden.'100 parts contain:parts of ashes. 100parts of these ashes from Norden parts contain: — consisted of:- Silica, and very fine siliceous sand 84'543 Silica and siliceous sand. 79600 Alumina 3458 ~Alumina - 6288Peroxide of iron 3'488 Alumina: - 6'288 Peroxide of iron. 0857 Peroxide of manganese 0560 Peroxide of iron -.0'857 Lime 0'319 Peroxide of manganese - 0'400 Magnesia -— 0'740 Carbonate of lime 7652 Manesia ar - 0740 Carbonate of magnesia 1a640 sh. - a trace Potash.... -. 08 Soda, in combination with silica 6'004 Potash ~~~~~~~~0'080 ~~~Soda -~028. - oo Phosphoric acid, in combination with Soda -0'028, Phosphoric acid - 0215 lime 0260 Sulphuric acid -. - 0'008 Sulphate of lime (gypsum). 3235 Sulphuric acid Chioune. -.. 0005 ~Chlorine -. 0'008 Chlorine...0'005 Huimus, soluble in alkalies - - 0'4.16 Huntus and nitrogenous matter - 0'196 Soils such as this, after having been 100'000 burned several times, and made to produce buckwheat, are'completely deprovedu of The portion ofthe soil subjected to analyouckwheat, are completely deprived of their potash and oda; and sis was taken at a depth of 10 inches, from n consequence a field which had received no manure for of this are rendered quite barren. Hence it is that ashes of wood exert such an astonish- veralears. t had previously produced ing effect upon them. tn succession barley, beans, wheat, and grass, the lattecr for two years. The soil is 25. Analysis of a very fertile loamy sand, grass, the lattr for two years. The soil s from Osnabriick, near Rotherfeld. It is re- remarkable, in a chemical point of view, from the large quantity of soda which it markable for being manured only once every containsh lta ough the sulphuric acid 10 or 12 years, and bears beautiful wheat as ontains. Altough the sulphuric acid, chlorine, and potash are -present in, small the last crop. 100 parts contain: otash arepresent in small quantity, yet this does not present any barSilica, with coarse siliceous sand 86'200 rier to the developement of the plants, as the Alumina... 2000 surface-soil is 18 inches in depth. Peroxide and protoxide of iron, with a 27. Analysis of a heavy alluvial soil in little phosphoric acid 2'900 the vicinity of Norden. 100 parts contain: Peroxide of manganese. - 0100 Carbonic actd, and, a little phosphate of Silica, and very fine siliceous sand 79'174 lime... 4'160 Alumina 3016 Carbonate of magnesia 0'520 Peroxide of iron 4 4960 Potash and soda 0035 Peroxide of manganese 0600 Phosphoric acid 0020 Carbonate of lime. 2171 Sulphuric acid O-002-1 Carbonate of magnesia 2226 Chlorine - -0'010 Potash, in combination with silica - 0'025 Humus, soluble in alkaline carbonates - 0544 Soda, idem.. 6349 Humus 3'370 Phosphoric acid 0534 - - - ~~0'534 N itrogenous matter - 0120 Sulphuric acid a trace Chlorine... 0'005 100'000 Humus, soluble in alkalies - 0782 Humus with nitrogenous matter 0158 The soil in question lies on the southern exposure of a hill, which consists, of layers 100'000 of limestone and marl. The rain-water penetrates through these layers, and becomes The specimen for analysis was taken at a saturated with the soluble salts contained in depth of 10 inches from the surface of a them, such as potash, gypsum, common field, which had been manured five years themsucaspotah,_gpsu,_comon previously, and had produced since that time The portion of the sfacesoil subjected to rape, rye, wheat, and beans. The crops of * The portion of the suface-soil subiected to all these were plentiful, and of excellent analysis was taken from the field after long.con- all e wre tinued rain. Hence the small quantity of salts of quality. It is singular that this soil, which potash and soda. contains such a small proportion of gypsum, 80 AGRICULTURAL CHEMISTRY. should be adapted for the cultivation of Peroxide of manganese - - - - 2Cd60 beans, and must be ascribed to the depth of Lime (0'9Y42 the surface-soil. Yet, notwithstanding this, Manesia 1 —40 n lPotash......0'050 gypsum would form a beneficial manure to,Soda. -. 0'012 the land. Phosphoric acid - 0'482 28. Analysis of a very fertile alluvial soil, Sulphuric acid - 0'012 from Honigpolder; no manure had ever Chlorine 0008 been applied to it. 100 parts contain:- Humus soluble in alkaline carbonates o 0897 Humus and nitrogenous matter - 0'138 Siliceous sand separated by the sieve - 45 Earthy portion of the soil - - 95'5 100'000 _.- 31. Surface-soil of a field near Dracken100.0loo burg; it produces very bad red clover. 100 100 parts of the latter consisted of:- parts contain:Silica, with very fine siliceous sand - 92'014 Silica, and fine siliceous sand - 64'800 Alumina 2'652 Alumina. 500 Peroxide of iron. - 3192 Peroxide of iron 6100 Peroxide of manganese. 0'480 Peroxide of manganese 0- 090 Lime - - - 0243 Lime - - 5'880 Magnesia - 0700 Magnesia 0'840 Potash combined with silica 0.125 Potash, principally in combination with Soda, idem 0'026 silica 0'210. Phosphoric acid, in combination with lime 0'078 Soda, idem -. 0'393 Sulphuric acid' a trace Phosphoric acid combined with lime 0'430 Chlorine -- a trace Sulphuric acid, idem 0210 Humus and nitrogenous matter - - 0150 Chlorine (in common salt) 0201 Humus soluble in'alkaline carbonates 0'340 Carbonic acid, combined with lime - 3.920 Humus soluble in alkalies - -. 2'540 100.000 Humus. 5-600 Nitrogenous matter 1582 The cause that clover will not flourish on Water. -. - 1'504 this soil is probably due to the deficiency of gypsum and common salt. 1000oo0 32. Surface-soil of a field near PaddingCorn has been cultivated for seventy years buttel. This field is particularly adapted upon this soil, which has never received forthegrowth of red clover. 100 parts condung or any other kind of manure; it is, sist of:however, occasionally fallowed. The sub- Silica and siliceous sand - - - 93'720 soil retains the same composition as the Alumina - e. 1'740 surface-soll for a depth of 6-12 feet, so that Peroxide of iron - 2'060 it may be considered inexhaustible. When Peroxide of manganese 0320 Lime. 0'121 one portion of the soil is rendered unfitted Magnesia.-0700 for use, the inferior layers are brought up to Potash, principally in combination with silica 0'062 the surface. Soda, idem. - 0'109 29. Analysis of a soil from Rahdingen, Phosphoric acid -. 0'103 near Balje. In this case the sea has assisted' Sulphuric acid 0005 in the formation of the soil. The field Chlorine (in common salt) - 0050 Humus soluble in alkaline carbonates - 0890 yielded beautiful corn after being manured Humus with nitrogenous matter - - 0120 with stable dung, being particularly remarked for its fine crops of wheat, beans, 100000 and winter barley. 100 parts contain: SOILS IN BOHEMIA. Silica, siliceous sand, and silicates. - 87 012 Alumina -. 4 941 33. Surface-soil of a very fertile field in Peroxide of iron 2430 the province of Dobrawitz and Lautschin. Peroxide of manganese - 0192 ~ime - ~ -. > * 0 I292 100 parts gave Magnesia 0'145 Siliceous sand, with much magnetic iron Potash and soda soluble in water - 0'005 sand - 4'286 Phosphoric acid ~ - 0'114 Earthy part separated by the sieve - - 95'714 Sulphuric acid, 0'074 Chlorine (in common salt) - ~ 0.003 100'000 Humus, soluble in alkaline carbonates - 0'658 Humus.- - 2668 An aqueous infusion of the soil contained Nitrogenous matter - - - 1412 gypsum, common salt, magnesia, and huWater. -. 0'042 nrus. 100 parts of the soil gave:100'000 Silica -. - 89'175 Alumina 2'652 30. Soil of a field remarkable fc:- produ- Protoxide and peroxide of iron 3'136 cing large crops of hemp and' horse-radish. Peroxide of manganese. - 0'320' 100 parts consisted of: - Lime. 1:200 Magnesia - 1040 Silica and siliceous sand - - - 84.021 Potash, in combination with silica - 0'075 Alumina -. - - 4'498 Soda, idem (principally) - - - 0354 Peroxide of iron - -. 5-120 Phosphoric acid, in combination with lime 0'377 CONSTITUENTS OF SOILS. 81 Sulphuric acid, idem - 0-081 of Nebstein. It has never been manured or Chlorine (in common salt) - 0066 allowed to lie fallow, and yet has produced Humus soluble in alkalies' - 0920 for the last 160 years the most beautiful Humus 0-0456 Nitrogenous matter. -.-.- 0'208 crops; thus furnishing a remarkable example of unimpaired fertility. 100'000 parts 100'000 of this soil consisted of: 34. Surface-soil of a very fertile field in Course and fine siliceous sand, with a the province of Dobrawitz and Lalvtshlin. little magnetic iron sand - - 35'400 100 parts of the earth consisted o[: — Earthy matter. 64'600 Siliceous sand, with a little magnetic iron, o100000 sand 43 780 Finer part separated by the sieve - 56-220 100 parts of the earth yielded to water 0'010 sulphuric acid, 0'010 chlorine, 0'007 soda, 100'000' 0-012 magnesia, 0'010 potash, with -a little 100 parts yielded to water 0-175 part of silica, humus, and nitrogenous matter, but salts, consisting of common salt, gypsum, no appreciable trace of nitrates. 100 parts magnesia, and humic acid. 100 parts, by of the soil contained:weight, of the earth consisted of;- Silica - - 77'209 Alumina- 8514 Silica - -' 89-634 Peroxide of iron - - 6592 Alumina - 3224 Peroxide of manganese 1 520 Protoxide-and peroxide of iron - - 2944 Lime 0927 Peroxide of manganese - - 11.60 Magnesia 1-160 Lime - 0.349 Potash, principally in combination with Magnesia - - 0300 silica - 0140 Potash in combination with silica - - 0160 Soda, idem - 0640 Soda, idem 0428 Phosphoric acid, combined with lime and Phosphoric acid, in combination with lime 0"246 iron 0,651 Sulphuric acid, idem - - - 0 005 Sulphuric acid, combined with lime - 0011 Chlorine (in common salt) - 0012 Chlorine (in common salt) - 0010 Humus soluble in alkalies - - 0- 750 Humus soluble in alkalies - 0978 Humus.0'340 Humus 0.540 Nitrogenous matter - - - 0448 Nitrogenous matter - 1108 100'000 100'000 35. Analysis of a soil formed by the dis- apparent from the above analysis mtegration of basalt. 100 parts of the earth that notwithstanding thelong period during consisted of:- * which this land has been cultivated without Siliceous sand, with very much magnetic manure, it still remains very rich in matters iron sand - - - 8-428 adapted for the nutrition of plants. Earthy portion of the soil - - 91572 109'0000 SOILS IN HUNGARY. The aqueous infusion of the earth' con- 37.'Analysis of a very fertile soil from tained only traces of common salt and gyp- Eskkang. 100 parts of the earth consum, with humus, lime, and magnesia. tained:100 parts consisted of:Very gei siliceous sand - - 2'820 Silica -. 83642'Eariy matter - - 97'180 Alumina - -. 3'978 Protoxide and peroxide of iron e - 5!312 100'000 Peroxide of manganese - - - 0960 LimPeroide of manganese 0'960 The aqueous decoctlon of the soil contained Lime 1'976 Magnesia -. - 0'650 principally gypsum, common salt, silica, Potash, in combination with silica - 0080 magnesia, and humus. 100 parts-of the soil Soda, idem 0'145 yieldedPhosphoric acid, in combination with lime 0'273 Sulphuric acid, idem -a trace Silica - 76'038 Humus soluble in alkaline carbonates - 1270 Alumina - 4 654 Chlorine -a trace Peroxide and protoxide of iron - 6112 Humus - 0234 Peroxide of manganese -. 0900 Nitrogenous matter -. - 1480 Carbonate of lime - - 3'771 Carbonate of magnesia - -. 4066 100o000 Potash combined with silica 0 030 M Soda combined with silica - 1'373 Manure consisting of gypsum, common Phosphoric acid, combined with lime - 0546 salt, or ashes'of wood, would be highly con- Sulphuric acid - 0 021 ducive to the fertility of this land. Chlorine in common salt 0'015 Humus soluble in alkalies - 1'160 Humus...... 1'100 SOILS IN THE ~" MARKGRAFSCHAFT MAHREN.? eumus 1100 Nitrogenous organic matter - 0208 36. Surface-soil, of a field very remarka- 100,000 ble for its fertility. The field is called Subsoil of the same field at a depth of two Raargraben, and is situated near the village feet. 100 parts consist of:11 82 A~~.AGRICULTURAL CHEMISTRY. Very fine si'ceous sand with scales of ric acid, potash, soda, and manganese. All mica - - 2'408 of these must have been present in the soil, Earth separated by the sieve - 97'592 for we are informed that it produced good 0'000 hops, for which these ingredients are indis100 parts of the earth contain': — pensable 40. A good turnip soil from Holkham, Silica - - - - 59'581 Norfolk, yielded to Davy:Alumina - - 3224 Peroxide and protoxide of iron - Siliceous sand 88888 Peroxide of manganese - - 0720. 1666' SAlumina..222 Carbonate of lime o - 17953 Peroxide of iron, 0'334 Carbonate of magnesia - - 1105 aPeroxide of iron, e 0334 Potash combined with silica 0'150 Soda, principally combined with silica 0- 891 Vegetable and saline matter 0556 Phosphoric acid combined with lime - 0-84:6 Moisture o 0 334 Sulphuric acid, idem - - 0'004 Chlorine in common salt - - 0004 Humus soluble in alkalies - - 0536 In this case also, phosphoric acid, manHumus with nitrogenous organic matter 0'120 ganese, potash, magnesia, &c., have es100000 caped detection by this acute chemist; yet BELGIUM. doubtless they must be present in the soil, for we are informed that it produces good 38. Surface-soil of a field distinguished turnips. for its fertility. It had received no manure 41. An excellent wheat soil from the for twelve years previous to the time at neighbourhood of West Drayton, Middlewhich the analysis was executed. The ro- sex, according to Davy. 100 parts contation of crops for the latter nine years was tained: as follows:- 1. beans, 2. barley, 3. potatoes, Sand and silica ~. ~72'800 4. winter barley with red clover, 5. clover, Alumina. - 11600 6. winter barley, 7. wheat, 8. oats; during Carbonate of lime.11-200 the ninth year it was allowed to lie fallow. Humus and moisture - 4.400 The soil is more clayey than loamy, and of 100'000 a very fine grain. Water extracted from This analysis has been executed so imperthe soil, 0'013 soda, 0'002 lime, 0-012 mag- feetly ta nesia, 0009 sulphuric acid, 0003 potash, fe tly, hat it only conveys a very feeble 0'003 chlorine, with traces of silica and hu- representation of the nature of the soi. A nus. 100 parts contained soil which bears good wheat must contain phosphate of potash, soda, chlorine, and Silica 64 517 sulphuric acid; yet none of these are exhiAlumina. 4'810 bited by the analysis. Peroxide and protoxide of iron 8'316 Peroxide of manganese - - 0'800 42. Surface-soil of a fertile field in the Carbonate of lime - - 9403 neighbourhood of Bristol.' 100 parts con Carbonate of magnesia - 10'3Gt tained: — Potash, principally combined with silica 0'100 Silica and siliceous sand - - 60'000 Soda.... 0'013 Alumina.. 12'000 Phosphoric acid.- - 1'221 Peroxide of iron -. 3'500 Sulphuric acid. - - 0'009 Sulphuric acid X - 0009 Lime (carbonate) -. 7500 Chlorine 0'003 Magnesia. 0'500 Humus - - 0'447 Humus. 1'250 Saline and extractive matter - - 0750 100'000 Water. - - 14500 ENGLAND. 39. Surface-soil of a very fertile sandy 100 000 field from the vicinity of Tunbridge, Kent, Davy has made several analyses of variaccording to Davy. 100 parts consisted ous fertile soils, and since his' time numerous of — - other analyses have been published; but they are all so superficial, and in most cases Loose stones and gravel - 13'250 so inaccurate, that we possess no means of Sand and silica -. 58250 Alumina - *.. 3'250 ascertaining the composition or nature of Peroxide of iron - - o 1250 English arable land. Carbonate of lime -. 4.750 SWEDEN. Carbonate of magnesia - - - 0.750 Common salt and extractive matter - 0'750 43. Surface-soil of a field which produces Gypsum.0'500 the most abundant crops, and has never Matter destructible by heat' - 3750 been manured. (Berzelius.) 100 parts conVegetable fibre 3'500 sist of:Water. -. - 5000 Loss. - - - 5000 Siliceous sand. - 57'900 Silica - 14'500 00'000 Alumina.. - 2'000 The great Davy, who was convinced of Phoiphates of lime nd iron, 6100 the importance of the inorganic constituents Carbonate of magnesia' - 1.00 Of soils, has omitted to detect the phospho- In lsoluble extractive matter - - 1250 CONSTITUENTS OF SOILS. 83 Insoluble extractive matter destructible by Humus, soluble in alkalies - - 1950 heat - 4000 Nitrogenous organic matter - 0. 236 Animal matter.. -. 1600 Wax and resinous matter ~ - 0'025 Resin. 0'250 Loss.. -: 0'400 100o000 47. (A.) Surface-soil of a mountainous -100000 district in the neighbourhood of Ohio. (B.) This great chemist has strangely omitted Analysis of the subsoil. This soil is also to detect in the soil potash, soda, chlorine, distinguishedforitsgreatfertility. 100parts sulphuric acid, and manganese. As this contain soil is eminent for its fertility, there cannot be the slightest doubt that all these ingre- Silica, with fine siliceous sand - 87'143 94'261 dients must have existed in it in notable Alumina. 5'666 1'376 quantity. Peroxide and protoxide of iron - 2220 2'336 Peroxide of manganese - - 0360 1'200 ISLAND OF JAVA. Lime - - - 0564 0.243 44. A very fine-grained loamy soil, co- Magnesia - 0312 0'310 loured yellow by peroxide of iron, consisted Potash, principally combined with.12 0'240 ~~~~~of:- -'. silica 0120 0240 of:-, Soda - - 0'025. Silica and siliceous sand - 67'660 Phosphoric acid. - 0'060 a trace Alumina - - - 13'572 Sulphuric acid - - 0027 0'034 Peroxide and protoxide of iron - - 10'560 Chlorine.-. 0'036 a trace Peroxide of manganese - - 1640 Humus soluble in alkalies 1.304 Lime - - - 0912 Humus 1'072 Magnesia - - 0570 Carbonic acid, combined with lime 0'080 Potash, principally in combination with Nitrogenous organic matter - 1011 silica -. -. 0'030 Soda, idem. - - 0'184 100'000 100:000 Phosphoric acid.. 0,391 In the preceding part of the chapter we SuChlophurinec acid -. 0038 have inserted a number of analyses of variChlorine - - - 0010 Humus -. - 0368 ous soils, as well as the conclusions deduced Water with carbonic acid - - 4065 from them, by means of which the farmer may be enabled to ascertain the manures 100'000 best adapted for each variety of soil. By inWEST INDIES (rORTO RICO.) specting the analyses of the sterile soils, it 45. -Surface-soil of a very barren field. will be apparent that it is in the power of 100 parts contained: — -chemistry to point out the causes of their..Silica and siliceous sand' - - 70'90sterility. The general cause which conSAlumina and siliceous sand 7090 duces to the sterility of soils is either the abAlumina ot 6996ndispensable Peroxide and protoxide of iron (much mag- sence of certain constituents indispensable netic iron sand) - 6-102 for the growth of plants, or the presence Peroxide of manganese - - 0'200 of others which exert an injurious or poiLime. 2'218 sonous action. The analyses are those of Magnesia - -- 3'280 Dr. Sprengel,-a chemist who has unceasPotash - - - 0'130 Carbonate of soa - - - 6556 ingly occupied himself for the last twenty Phosphoric acid, combined with lime - 1362 years in endeavouring to point out the imSulphuric acid, combined with lime - 0149 portance of the inorganic ingredients of a Chlorine in common salt -. 0067 soil for the developement of plants cultivated Humus, soluble in alkalies - 0'540 upon it. He considers as essential all the Humus..... 1'500 inorganic bodies found in.the ashes of plants. 1N0000 Now, although we cannot coincide with him in the opinion that iron and manganese are This soil is imprlo ved- by gypsum. Its indispensable for vegetable life, (for these sterility is due to the excessivequantity of' bodies are found as excrementitious matter carbonate of soda which is present. I only in the bark, and never form a constituNORTH AMERICA. ent of an organ,) yet we gratefully acknow46. Surface-soil of alluvial land in Ohio, ledge the valuable services which he has rendered to agriculture, by furnishing a natural remarkable for its great fertility. 100 parts dered t agriculture, by furnishing a natural consisted of: explanation of the action of ashes, marl, &c., in the improvement of a soil. Sprengel has Silica and fine siliceous sand. - 79538 shown that these mineral manures afAlumina, -7306 ford to a soil-alkalies, phosphates, and sulPeroxide and protoxide of iron. (much magnetic iron sand) -. - 5'824 phates; and further, that they can exert a, Peroxide of manganese - - 1'320 notable influence only on those soils in Lime... 0-619 which they are absent or deficient. In a Magnesia - - 1024 former chapter of this book I have endeaPotash, principally combined with silica 0'200 voured to point out the importance of consiPhosphoric acid combined with lime and - dering these constituents as intimately conoxide of iron. 1*776 nected with the vital processes of the vegeSulphuric acid, combint'd with lime. 0'122 table organism, and have shown that the Chlorine - - 0-036 different families of plants contain uneqw. 84 AGRICULTURAL CHEMISTRY. quantities of inorganic ingredients. This of calcium, for example.) But it acts also subject has been left unexamined by Spren- as a sulp1ate, and when useful as such cangel, yet it is one of much importance; for not be replaced by any other salt of lime the application of manures must be regulated which does not contain sulphuric acid. by the composition of the plants which are Hence gypsum can be. replaced as a macultivated on any particular soil. Still the nure only by a mixture of a salt of lime composition of the soil must always be kept with ammonia, and a salt of sulphuric acid. in view. Thus it would be perfect extrava- Sulphate of ammonia can therefore be subgance to manure certain soils with marl, stituted for gypsum, and exerts a more rapid ashes, or gypsum; whilst, on the contrary, and effectual action. In France, sulphuric these compounds would produce the most acid has been poured upon the fields after beneficial results on other lands. the removal of the crops, and has been In a' former part of the work, the princi- found to form a good manure. i But this is pal action of gypsum upon vegetation was merely a process.for forming gypsum in ascribed to the decomposition and fixation situ; for the soils upon which it is applied of the carbonate of ammonia contained in contain much lime, which enters into comrain-water; but gypsum exerts a twofold bination with the sulphuric acid. It would action. The power of decomposing car- certainly be much more advantageous to bonate of ammonia, and of fixing the am- form sulphate of ammonia by adding the monia, is not peculiar to gypsum, but is acid to putrefied urine, and to apply this shared also by. other salts of' lime (chloride mixture to the field. A PP E DIX TO?ART I. EXPERIMENTS AND OBSERVATIONS ON TIlE ACTION OF CHARCOAL FROM WOOD ON VEGETATION.-BY EDWARD LUKAS.* "IN a division of a low hot-house in the of experiments, the results of which may botanical garden at Munich, a bed was set not be uninteresting; for, besides being of apart for young tropical plants, but instead practical use in the cultivation of inost of being filled with tan, as is usually the plants, they demonstrate also several facts case, it was filled with the powder of char- of importance to physiology. The first excoal (? mom'rma.. which could be easily pro- periment which naturally suggested itself cured,) tne.arge pieces of charcoal having was to mix a certain proportion of charcoal been previously separated by means of a with the earth in which different plants sieve. The heat was conducted by means grew, and to increase its: quantity according of a tube of white iron into a hollow space as the advantage of the method was perin this bed, and distributed a gentle warmth, ceived. An addition of J charcoal, for examsuch as tan communicates, when in'a state pie, to vegetable mould, appeared. to answer of fermentation. The plants placed in this excellently for the Gesneia. and Gloxinia, bed of charcoal quickly vegetated, and ac- and also for the tropical.Aroidece with tubequired a healthy appearance. Now, as is rous roots. The first two soon excited the always the case in such beds, the roots of attention of connoisseurs, by the great many of the plants penetrated through beauty of all their parts and their general the holes in the bottom of the pots, and appearance. They surpassed very quickly then spread'themselves out; but these those cultivated in the common way, both plants evidently surpassed in vigour and in the thickness of their stems and dark general luxuriance plants grown in the colour of their leaves; their blossoms were common way-for example, in tan. Seve- beautiful, and their vegetation lasted much ral of them, of which I shall only specify longer than usual, so much so, that in the the beautiful Thunbergia alata, and the ge- middle of November, when other plants of nus Peireskice, throve quite astonishingly; the same kinds were dead, these were quite the blossoms of the former were so rich, fresh and partly in bloom. flroidece took that all who saw it affirmed they had never root very rapidly, and their leaves surpassed before seen such a specimen. It produced much in size the leaves of those not so al o a number of seeds without any artificial treated; the species which are reared as aid, while in most cases it is necessary to ornamental plants on account of the beauti. apply the pollen by the hand. The Peires- ful colouring of their leaves, (I mean such kice grew so vigorously, that the P. aculeata as the Caladium bicolor, Picturn, Pcecile, produced shoots several ells inlength, and the &c.,)'were particularly remarked for the P. g-randifoliaacquired leaves a footin length. liveliness of their tints; and it happened'These facts, as well as the quick germina- here also, that the period of their vegetation tion of the seeds which had been scattered was unusually long. A cactus planted in a spontaneously, and the abundant appearance mixture of equal parts of charcoal and earth of young Iilices, naturally attracted my at- throve progressively, and attained double of tention, and I was gradually led to a series its former size in the space of a few weeks. * See page 27. IThe use of the charcoal was very advan APPENDIX TO PART I. 85 tageous with several of the Bromeliacere, and have most effect when allowed to lie during Lilacece, with the Cilrus, and Begonia also, the winter exposed to the action of the air. and even with the Palmrce. The same ad- In order to ascertain the effects of different vantage was found in the case of almost all kinds of charcoal, experiments were also those plants for which sand is used, in order made upon that obtained from the hard to keep the earth porous, when charcoal was woods and peat, and also upon animal charmixed with the soil instead of sand; the coal, although I foresaw the probability that vegetation was always rendered stronger and none of them would answer so well as, that more vigorous. of pine-wood, both on account of its porosity "At the same time that these experiments and the ease with which it is decomposed. were performed with mixtures of charcoal "It is superfluous to remark, that in treatwith different soils, the charcoal was also ing plants in the manner here described, they used free from any addition, and in this case must be plentifully supplied with water, the best results were obtained. Cuts of since the air havingf such free access peneplants from different genera took root in it trates and dries the roots, so that unless this well and quickly; I mention here only the precaution is taken, the failure of all such Euphorbia fastuosa and fulgens which took experiments is unavoidable. root in ten days, Pandanus utilis in three "The action of charcoal consists primarily months, P. canariylltfolius, Chanicedorea ela- in its preserving the parts of the plants with tior in four weeks, Piper Zni'uln, Begonia, which it is in contact-whether they. be Ficus, Cecropia, Chiococca, Buddleya, Hakea, roots, branches, leaves, or pieces of leaves PhyllanZthus, Capparis, Laurus, Stifftia, Jac- — uncharnged in their vital power for a long quinia, MJimosa, Cactus, in from eight to ten space of time, so that the plant obtains time days, and several others amounting to forty to develope the organs which are necessary species, including Iex, and many others. for its further support and propagation. Leaves, and pieces of leaves, and evenpe- There can scarcely be a doubt also that the dumnculi, or petioles,'took root and in part charcoal undergoes decomposition; for after budded in pure charcoal. Amongst others being used five to six years it becomes a we may mention thefoliola of several of the coaly earth; and if this is the case, it must Cycadece as having taken root, as also did yield carbon, or carbonic oxide, abundantly parts of the leaves of the Begonia Telfairice, to the plants growing in it, and thus afford and Jacaranda brasiliensis; leaves of the the principal substance necessary for the EIuphorbia fastuosa, Oxalis Barrilieri, Ficus, nutrition of vegetables.t In what other Cyclantwen, Polyanthes, MJtesembryanthemum; manner indeed can we explain the deep also the delicate leaves of the Lophospermumn green colour and great luxuriance of the and Jltartynia, pieces of a leaf of the.g'ave leaves and every part of the plants, which americana; tufts of Pinus, &c.; and all with- can be obtained in no other kind of soil, acout the aid of a previously formed bud.: cording to the opinion of men well qualified "Pure charcoal acts excellently as a to judge? It exercises likewise a favourable means of curing unhealthy plants. A Do- influence by decomposing and absorbing the 7ianthes excelsa, for example, which had matters excreted by the roots, so as to keep been drooping for three years, was rendered the soil free from the putrefying substances completely healthy in a very short time by which are often the cause of the death of the this means. An orange-tree which had the Tpongiolce. Its porosity, as well as'the power very common disease in which the leaves which it possesses of absorbing water with become yellow, acquired within four weeks rapidity, and, after its saturation, of allowits healthy green colour, when the upper ing all other water to sink through it, are surface of the earth was removed from the causes also of its favourable effects. These pot in which it was contained, and a ring experiments show what a close affinity the of charcoal of an inch in thickness strewed component parts of charcoal have to all in its place around the periphery of the pot. plants, for every experiment was crowned The same was the case with the Gardenia. with success, although plants belonging to a "I should be led too far were I to state all the results of the experiments which I have made with charcoal. The object of this *: M. Lukas has recently repeated these experi. ments, and found that the animal charcoal obpaper is merely to show the general effect tained by the calcination of bones possesses a deexercised by this substance on vegetation; cided advantage over all other kinds of charcoal. but the reader who talkes particular interest which he subjected to experiment.-Liebig's Anin the subject will find more extensive ob- nalen, Banld xxxix. Heft I. S. 127. serlvajtions in the'lgemeitze Deutsche Gartten- t As some misconception has arisen regarding eit of Oto a Ditrich in Berlin or this explanation of the action of charcoal upon veLontdon'sOt Gardenetr'sc, azin or n o getation, and an ideapropagated that the introLoudon's Gardener's JAIag'azine for March, duction of these opinions into this work incorpo1841.' rated them with those of Liebig, it is necessary to " The charcoal employed in these experi- state that they are merely inserted here as part of ments was the dust-like powder of charcoal the papers of M. Lukas. The true explanation from firs and pines, such as is used in the has been given in a former part of the work, viz., that charcoal possesses the power of absorbing forges of blacksmiths, and may be easily carbonic acid and ammonia from the atmosphere, procured in any quantity. It was found to which serve fo: the nourishment of plants.-ED. IH 86 AGRICULTURAL CHEMISTRY. great many different families were subjected barley and esparcet, or lucerne; in the sixth to trial." (Buchner's Repertorium, ii.' Reihe, year the young stocks are planted, but not xix. Bd. S. 38.) manured till the ninth. ON A MODE' OF MANURING VINES. ON THE MANURING OF THE SOIL IN VINEYARDS. The observations contained in the following pages should be extensively known, be- "In reference to an article in your paper, cause they furnish a remarkable proof of the No. 7, 1838, and No. 29, 1839, I cannot principles which have been stated in the omit the opportunity of again calling the preceding part of the work, both as to the public attention to the fact, that nothing rmanner in which manure acts, and on the more is necessary for the manure of a vineorigin of the carbon and nitrogen of plants. yard than the branches which are cut from They prove that a vineyard may be re- the vines themselves. tained in fertility without the application " My vineyard has been manured in this of animal matters, when the leaves and way for eight years, without receiving any branches pruned-from the vines are cut into other kind of manure, and yet more beautismall pieces and used as manure. According ful and richly laden vines could scarcely be to the first of the following statements, both pointed out. I formerly followed the method of which merit complete confidence, the usually practised in this district- and was perfect fruitfulness of a vineyard has been obliged in consequence to purchase manure maintained in this manner for eight years, to a large amount. This is now entirely and according to the second statement for saved, and my land is in excellent condition. ten years. "When I see the fatiguing labour used Now, during this long period, no carbon in the manuring of vineyards-horses and was conveyed to the soil, for that contained men toiling up the mountains with unnein the pruned branches was the produce of cessary materials-I feel inclined to say to the plant itself, so that the vines were placed all, Come to my vineyard and see how a exactly in the same condition as trees in a bountiful Creator has provided that vines forest which received no manure. Under shall manure themselves, like the trees in a ordinary circumstances a manure containing forest, and even better than they! The potash must be used, otherwise the fertility foliage falls from trees in a forest, only of the soil will decrease. This is done in all when they are withered, and they lie for wine-countries, so that alkalies to a very: years before they decay; but the branches considerable amount' must be extracted from are pruned from the vine in the end of July the soil. or beginning of August whilst still fresh and When, however, the method of manuring moist. If they are then cut into small pieces now to be described is adopted, the quantity and mixed wit the earth, they undergo of alkalies exported in the wine does not putrefaction so completely, that, as I have exceed that which the progressive disinte- learned by experience, at the end of four gration of the soil every year renders capable weeks not the smallest trace of them can be of being absorbed by the plants. On the found." Rhine 1 litre of wine is calculated as the yearly produce of a square metre of land "REMARzKS OF THE EDITOR.-We find (10'8 square feet English.) Now if we the following notices of the same fact in suppose that the wine is three-fourths satu- Henderson's' Geschichte der Weine der rated with cream of tartar, a' proportion alten und neuen Zeit:'much above the truth, then we remove from "'The best manure for vines is the every square metre of land'with the wine branches pruned from the vines themselves, only 1'8 gramme of potash. 1000 grammes cut into small pieces, and immediately mixed (1 litre) of champagne yield only 1.54, and with the soil.' the same quantity of Wachenheimer 1-72 -"These branches were used as manure of a residue which after being heated to red- long since in the Bergstrasse. M. Frauenness is found to consist of carbonates. felder says:t One vine-stock, on an average, grows on "' I remember that twenty years ago, a' every square metre of land, and 1000 parts man called Peter Miiller had a vineyard of the pruned branches contain 56 to 60 here which he manured with the branches parts of carbonate, or 38 to 40 parts of pure pruned from the vines; and continued this potash. Hence it is evident that 45 grammes, practice for thirty years. His way of applyor 1 ounce, of these branches contain as ing them was to hoe them into the soil after much potash as 1000 grammes (1 litre) of having cut them into small pieces. wine. But from ten to twenty times this "' His vineyard was always in a thriving quantity of branches are yearly taken from the above extent of surface. * Slightly abridged from an article by M. Kreba In the vicinity of Johannisberg, Rudes- of Seeheim, in the "Zeitschrift fir die landwirth. heim, and Budesheim, new' vines are not schaftlichen Vereine des Grosherzogthums Hes. helm, and Buieshelmb, new vines are not sen." No. 28, July 9, 1840. planted after the rooting out of the old stocks, t- Badisches landwirthschaftliches Wochenblatt, until the land has lain for five or six years in v. 1834, S. 52 and 79. CHEMICAL TRANSFORMATIONS. 87 condition; so much so indeed, that the pea- and then said to myself: If these branches sants here speak of it to this day, wondering can make the grass large, strong, and green, that old Miller had so good a vineyard, and they must also be able to make my plants yet used no manure.' grow better, and become strong-and green. " Lastly, Wilhelm Ruf of Schriesheim I dug therefore my vineyard as deep as if I writes: would put dung into it, and cut the branches -' For the last ten years I have been into pieces, placing them in the holes and unable to place dung on my vineyard. be- covering them with earth. In a year I had cause I am poor and can buy none. But I the very great satisfaction to see my barren was very unwilling to allow my vines to vineyard become quite beautiful. This plan decay, as they are my. only source of sup- I continued every year, and now my vines port in my old age; and I often walked very growv splendidly, and remain the whole anxiously amongst them, without knowing summer green, even in the greatest heat. what I should do. At last my necessities "' All my neighbours wonder very much became greater, which made rme more at- how my vineyard is so rich, and that I obtentive, so that I remarked that the grass tain so many grapes from it, and yet they was longer on some spots where-the branches all know that I have put no dung upon it of the vine fell than on those on which there for ten years."' were none. So I thought upon the matter, ]PART II. OF THE CHEMICAL PROCESSES OF FERMENTATION, DECAY AND PUTRE. FACTION. CHAPTER 1. which unites with one or more of the constituents of a compound, is quite analogous CHEMIC.AL TRANSFORMATIONS. to the decomposition of inorganic substances. When we bring sulphuric acid and nitrate WOODY fibre, sugar, gum, and all such of potash together, nitric acid is separated organic compounds, suffer certain changes in consequence of the affinity of sulphuric when in contact with other bodies, that is, acid for potash; in consequence, therefore, they suffer decomnposition. of the formation of a new compound (sulThere are two distinct modes in which phate of potash.) these decompositions take place in organic In the second form of these decomposichemistry. tions, the chemical affinity of the acting When a substance composed of two com- body causes the component parts of the pound bodies, crystallized oxalic acid for body which is decomposed to combine so as example, is brought in contact with concen- to form new compounds, of which either trated sulphuric acid, a complete decompo- both, or only one, combine with the acting sition is effected upon the application of a body. Let us take dry wood, for example, gentle heat. Now crystallized oxalic acid and moisten it with sulphuric acid; after a is a combination of water with the anhy- short time the wood is carbonised, while the drous acid; but concentrated sulphuric acid sulphuric acid remains unchanged, with the possesses a much greater affinity for water exception of its being united with more than oxalic acid, so that it attracts all the water than it possessed before. Now this water of crystallization from that substance. water did not exist as such in the Wood, In consequence of this abstraction of the although its elements, oxygen and hydrowater, anhydrous oxalic acid is set free; but gen; were present; but by the chemical atas this acid cannot exist in a free state, a traction of suilphuric acid for water, they division of its constituents necessarily en- were in a certain measure compelled to unite sues, by which carbonic acid and carbonic in this form; and in consequence of this, the oxide are produced, and evolved in the carbon of wood was separated as charcoal. gaseous form in equal volumes. In this Hydrocyanic acid, and water, in contact example, the decomposition is the conse- with hydrochloric acid, are mutually decomquence of the removal of two constituents posed. The nitrogen of the hydrocyanic (the elements of water,) which unite with acid, and a certain quantity of the hydrogen the sulphuric acid, and its cause is the supe- of the water, unite together and form amrior affinity of the acting body (the sulphuric Inonia; whilst the carbon and hydrogen of acid) for water. In consequence of the re- the hydrocyanic acid combine with the oxymoval of the component parts of water, the gen of the water, and form fornmic acid. The remaining elements enter into a new'form; ammonia combines with the muriatic acid. in place of oxalic acid, we have its elements Here the contact of muriatic acid with water in the form of carbonic acid and carbonic and hydrocyanic acid causes a disturbance oxide. in the attraction of the elements of both This form of decomposition, in which the compounds, in consequence of which they change is effected by the agency of a body arrange themselves into new combinations, 88 AGRICULTURAL CHEMISTRY. one of which-ammonia —possesses the an alloy of copper, zinc, and nickel, dispower of uniting with the acting body. solves -easily in this acid with evolution of Inorganic chemistry can present instances hydrogen gas. analogous to this class of decomposition Tin decomposes nitric acid with great faalso; but there are forms of organic chemi- cility, but water with difficulty; and yet, cal decomposition of a very different kind, when tin is dissolved in nitric acid, hydrogen in which none of the component parts of the is evolved at the same time, from a decornmatter which suffers decomposition enter position of the water contained in the acid, into combination with the body which de- and ammonia is formed in addition to oxide termines the decomposition. In cases of of tin. this kind a disturbance is produced in the In the examples here given the only commutual attraction of the elements of a com- bination or decomposition which can be expound, and they in consequence arrange plained by chemical affinity is the last. in themselves into one or several new combi- the other cases, electrical action ought to nations, which are incapable of suffering have retarded or prevented the oxidation of further change under the same conditions. the platinum or copper while they were in When, by means of the chemical affinity contact with silver or zinc, but, as experience of a second body, by the influence of heat, shows. the influence of the opposite electrior through any other causes, the composi- cal conditions is more than counterbalanced tion of an organic compound is made to by chemical actions. undergo such a change, that its elements The same phenomena are seen in a less form two'or more new compounds, this dubious form in compounds, the elements manner of decomposition is called a chemi- of which are held together only by a feeble cal tranJforemation or mnetamorphosis. It is affinity. It is well known that there are an essential character of chemical transfor- chemical compounds of so unstable a nature,' mations, that none of the elements of the that changes in temperature and electrical body decomposed are singly set at liberty. condition,.or even simple mechanical fricThe changes, which are designated by the tion, or contact with bodies of apparently terms fermentation, decay, and putrefaction, totally indifferent natures, cause such a disare chemical transformations effected by an turbance in the attraction of their constituents, agency which has hitherto escaped atten- that the latter enter into new forms, withtion, but the existence of which will be out any of them combining with the acting proved in the following pages. body. These compounds appear to stand but just within the limits of chemical combination, and agents exercise a powerful influence over them, which are completely deCHAPTER II void of action on compounds of a stronger affinity. Thus, by a slight increase of temON THE CAUSES WHICH EFFECT FERMENTA- perature, the elements of hypochlorous acid TION, IDECAY,5 AND PUTREFACTION. separate from one another with evolution of heat and light; chloride of nitrogen explodes ATTENTION has been recently directed to by contact with many bodies, which comthe fact, that a body in the act of combina- bine neither with chlorine nor nitrogen at tion or decomposition exercises an influence common temperatures; and the contact of upon any other body with which it may be any solid substance is sufficient to cause the in contact. Platinum, for example, does explosion of iodide of nitrogen, or fulminatnot decompose nitric acid; it may be boiled ing silver. with this acid without being oxidized by it, It has never been supposed that the causes even when in a state of such fine division, of the decomposition of these bodies should that it no longer reflects light (black spongy be ascribed to a peculiar power, dierent platinum.) But an alloy of silver and pla- from that which regulates chemical affinity, -tinum dissolves with great ease in nitric a power which mere contact with the down acid; the oxidation which the silver suffers of a feather is sufficient to set in activity, causes the platinum to submit to the same and which, once in action, gives rise to change; or, in other words, the latter body, the decomposition. These substances have from its contact with the oxidizing silver, always been viewed as chemical compounds acquires the property of decomposing nitric of a very unstable nature, in which the acid. component parts are in a state of such tenCopper does not decompose water, even sion, that the least disturbance overcomes when boiled in dilute sulphuric acid; but their chemical affinity. They exist only by the vis inertiae, and any shock or movement * An-essential distinction is.drawn in the follow- is sufficient to destroy the attraction of their ing part of the work. between decay and putre. component parts, and consequently their factiomz (Verwesung und Faulniss,) and they are existence in their definite form. shown to depend on different causes; but as the. Peroxide of hydrogen belongs to this class word decay is not generally applied to a distinct of bodies; it is decomposed by all substances species of decomposition, and does not indicate its o f attracting oxyge n from i, a nd true nature, I shall in future, at' the suggestion of capable of attracting oxygen from t, and he author, employ' the term eremacaeusis, the even by contact with many bodies, such as weaning of which has been already explained.-ED. platinum or silver, which do not enter into CHEMICAL TRANSFORMATIONS. 89 combination with any of its constituents. the act of combination or decomposition In this respect, its decomposition depends enables another body, with which it is in evidently upon the same causes which effect contact, to enter into the same state. It is that of iodide of nitrogen, or fuhnlminating evident that the active state of the atoms of silver. Yet it is singular that the cause of one body has an influence upon the atoms the sudden separation of the- component of a body in contact with- it; and if these parts of peroxide of hydrogen has been atoms are capable of the same change as the viewed as different from those of common de- former, they likewise undergo that change; composition, and has been ascribed to a new and combinations and decompositions are the power termed the catalytic force. Now, it consequence. But when the atoms of the has not been considered, that the presence second body, are not capable of such an of the platinum and silver serves here only action, any further disposition to change to accelerate the decomposition; for without ceases from the moment at which the atoms the contact of these metals, the peroxide of of the first body assume the state of rest, hydrogen decomposes spontaneously, al- that is when the changes or transformations though very slowly. The sudden separa- of this body are quite completed. tion of the constituents of peroxide of hydro- This influence exerted by one compound gen differs from the decomposition of gase- upon the other,' is exactly similar to that ous hypochlorousacid, or solid iodide of which a body in the act of combustion exernitrogen, only in so far as the decomposition cises upon a combustible body in its vicinity -; takes place in a liquid. with this difference only, that the causes A remarkable action of peroxide of hydro- which determine the participation and dugen has attracted much attention, because it ration of these conditions are different. For differs from ordinary chemical phenomena. the cause, in the case of the combustible This is the reduction which certain oxides body, is heat, which is generated every mosuffer by contact with this substance, on the ment anew; whilst in the phenomena of instant at which the-oxygen separates from decomposition and combination, which we the water. The oxides thus easily reduced, are considering at present, the cause is a are those of which the whole, or part at body in the state of chemical action, which least, of' their oxygen is retained merely by exerts the decomposing influence only so a feeble affinity, such as the oxides of silver long as this action continues. and of gold, and peroxide of lead. Numerous facts show that motion alone Now, other oxides which are very stable exercises a considerable influence on chemiin composition, effect the decomposition of cal forces. Thus, the power of cohesion peroxide of hydrogen, without experiencing does not act in many saline solutions, even the smallest change; but when oxide of when they are fully saturated with salts, if silver is employed to effect the decomposi- they are permitted to cool while at rest. In tion, all the oxygen of-silver is carried away such a case, the salt dissolved in a, liquid with that evolved from the peroxide of hy- does not crystallize;, but when a grain of drogen, and as a result of the decomposition, sand is thrown into the solution, or when it water and metallic'silver remain. When receives the slightest movement, the whole peroxide of lead is used for the same pur- liquid becomes, suddenly solid while heat pose, half its oxygen escapes as a gas. Per- is evolved.. The same phenomenon happens oxide of manganese may in the same man- with water, for this liquid may be cooled ner be reduced to the protoxide, and oxygen much under 320 F. (00 C.,) if lept comset at liberty, if an acid is at the sanie time pletely undisturbed, but solidifies in a mopresent, which will exercise an affinity for meat when put in motion. the protoxide and convert it into a soluble The atoms of a body must in fact be set salt. If, for example, we add to peroxide in motion before they can overcome the vis of hydrogen sulphuric acid, and then per- inertice so as to arrange themselves into ceroxide of manganese in the state of fine pow- tain forms. A dilute solution of a salt of der, much more oxygen is evolved than the potash mixed with tartaric acid yields no compound of oxygen and hydrogen could precipitate whilst at rest; out if motion is yield; and if we'examine the solution which communicated to the solution by agitating remains, we find a salt of the protoxide of it briskly, solid crystals of cream of tartar manganese, so that half of the oxygen has are deposited. A solution of a salt of magbeen evolved from the peroxide of that metal. nesia also, which is not rendered turbid by A similar phenomenon occurs, when car- the addition of phosphate of ammonia, debonate of silver is treated with several or- posits the phosphate of magnesia and amganic acids. Pyruvic acid, for example, monia on those parts of the vessel touched combines readily with pure oxide of silver, with the rod employed in stirring. and forms a salt of sparing solubility in In the processes of combination and dewater. But when this acid is brought in composition under consideration, motion, by contact with carbonate of silver, the oxygen overcoming the vis inertice, gives rise imof part of the oxide escapes with the car- mediately to another arrangement of the bonic acid, and metallic silver remains in atoms of a body, that is, to the production the state of a black powder. (Berzelius.) of a compound which did not before exist in Now no other explanation of these ple- it. Of course these atoms must previously nomena cain be given, than that a body in possess the power of arranging themsnelves 12 H: 90 CHEMICAL TRANSFORMATIONS. in a certain order, otherwise both friction ready sufficiently proved by the facts deand motion would be without the smallest rived from inorganic chemistry, but it is of influence. much more frequent occurrence in the reThe simple permanence in position of the lations of organic matter, and causes very atoms of a body, is the reason that so many striking and wonderful phenomena. compounds appear to present themselves, in By the terms fermentation, putrefaction, conditions, and with- properties, different and eremacausis, are meant tuose changes in from those which they possess, when they form and properties which compound orobey the natural attractions of their atoms. ganic substances undergo when separated Thus sugar and glass, when melted and from the organism, and exposed to the incooled rapidly, are transparent, of a con- fluence of water and a certain temperature. choidal fracture, and elastic and flexible to a Fermentation and putrefaction are examples certain degree. But the former becomes of that kind of decomposition, which we'dull and opaque on keeping, and exhibits have named transformations: the elements crystalline faces by cleavage, which belong'of the bodies capable of undergoing these to crystallized sugar. Glass assumes also changes arrange themselves into new comthe same condition, when kept soft by heat binations, in which the constituents of water for a long period; it becomes white, opaque, generally take a part. and so hard as to strike fire with steel. Eremacausis (or decay) differs from ferNow, in'both these bodies, the compound mentation and putrefaction, inasmuch as it molecules evidently have different positions cannot take place without the access of air, in the two forms. In the first form their at- the oxygen of which is absorbed by the detraction did not act in the direction in which caying bodies. Hence it is a process of their power of cohesion was strongest. It slow combustion, in which heat is uniis known also, that when sulphur is melted formly evolved, and occasionally even light. and cooled rapidly by throwing it into cold In the processes of decomposition termed water, it remains transparent, elastic, and fermentation and putrefaction, gaseous proso soft that it may be drawn out into long ducts are very frequently formed; which are threads; but that after a few hours or days, either inodorous, or possess a very offensive it becomes again hard and crystalline. smell.. The remarkable fact here is,. that the The transformations of those matters amorphous sugar or sulphur returns again which evolve gaseous products without into the crystalline condition, without any odour are now, by pretty general consent, assistance from an exterior cause; a fact designated by the termfermentation;. whilst which shows that their molecules have as- to the spontaneous decomposition of bodies sumed another position, and that they pos- which emit gases of a disagreeable smell, sess, therefore, a certain degree of mobility, the term putrefaction is applied. But the even in the condition of a solid. A very smell is of course no distinctive character rapid transposition or, transformation of this of the nature of the decomposition, for both kind is seen in arragonite, a mineral which fermentation and putrefaction are processes possesses exactly the same composition as of decomposition of a similar ikind, the one calcareous spar, but of which the hardness of substances destitute.of nitrogen, the other and crystalline form prove that its molecules of substances which contain it. are arranged in a different manner. When It has also been customary to distinguish a crystal of arragonite is heated, an interior from fermentation and putrefaction a parmotion of its molecules is caused by the ex- ticular' class of transformations, viz., those pansion; the permanence of their arrange- in which conversions and transpositions are ment is destroyed; and the crystal splinters effected without the evolution of gaseous with much violence, and falls into a heap products. But the conditions under which of small crystals of calcareous spar. the products of the decomposition present It is impossible for us to be deceived re- themselves are purely accidental; there is garding the causes of these changes. They therefore no reason for the distinction just are owing to a disturbance of the state of mentioned. the equilibrium, in consequence of which the particles of the body put.in motion obey other affinities or their own natural attractions. CHAPTER III. But if it is true, as we have just shown -it to be, that mechanical motion is sufficient FERMENTATION AND PUTREFACTION. to cause a change of condition in many bodies, it cannot be doubted that a body in SEVERAL bodies appear to enter spontathe act of combination or decomposition is neously into the states of fermentation and capable of imparting the same condition of putrefaction, particularly such' as contain motion or activity in which its atoms are to nitrogen or azotised substances. Now, it is certain other bodies: or in other words, to very remarkable, that very small quantities enable other bodies with which it is in con- of these substances, in a state of fermentatact to enter into combinations, or suffer de- tion or putrefaction, possess the power of compositions. causing unlimited quantities of similar matThe reality of this influence has been al- ters to pass into the same state. Thus, a CHEMICAL TRANSFORMATIONS. 91 small quantity of the juice of grapes in the and place, which the simple atoms take in act of fermentation, added to a large quan- the compound molecules. tity of the same fluid, which does not fer- VVhen we compare the composition of ment, induces the state of fermentation in organic compounds with inorganic, we are the whole mass. So likewise the most mi- quite amazed at the existence of. combinanute portion of milk, paste, juice of the tions, in one single molecule of which, beet-root, flesh, or blood, in the state of ninety or several hundred atoms or equiva putrefaction, causes fresh milk, paste, juice lents are united. Thus, the compound atom of the beet-root, flesh or blood, to pass into of an organic acid of very simple composi. the same condition when in contact with tion, acetic acid for example, contains twelve them. equivalents of simple elements; one atom These changes evidently differ from the of kinovic acid contains 33, 1 of sugar 36, class of common decompositions which are I of amygdalin 90, and 1 of stearic acid 138 effected by chemical affinity; they are equivalents. The component parts of anichemical actions, conversions, or decompo- mal bodies are infinitely more complex even sitions, excited by contact with bodies al- than these. ready in the same condition. In order to Inorganic compounds differ from organic form a clear idea of these processes, analo- in as great a degree in their other characters gous and less complicated phenomena must as in their simplicity of constitution. Thus, previously be studied. the decomposition of a compound atom of The compound nature of the molecules sulphate of potash is aided by numerous of an organic body,'and the phenomena causes, such as the power of cohesion, or presented by them when in relation with the capability of its constituents to form other matters, point out the true cause of solid, insoluble, or at certain temperatures these transformations. Evidence is afforded volatile' compounds with the body' brought even by simple bodies, that in the formation into contact with:it, and nevertheless a. vast of combinations, the force with which the number of other substances produce in it combining elements adhere to one another not the slightest change. Now, in the deis inversely proportional to the number of composition of a complex organic atom, simple atoms in the compound molecule. there is nothing similar to this. Thus, protoxide of manganese by absorp- The empirical formula of sulphate of tion of oxygen is converted into the sesqui- potash is S1K4. It contains only 1 eq. of oxide, the peroxide, manganic and hyper- sulphur, and 1 eq. of'potassium. We may manganic acids, the number of atoms of suppose the oxygen to be differently distrioxygen being augmented by by, by 2, buted in the compound, and by a decompoand by 5. But all the oxygen contained in sition we may remnove a part or all of it, or these compounds, beyond thatwhich belongs replace one of the: constituents of the comto the protoxide, is bound to the manganese pound by another substance. But we canby a much more feeble affinity; a red heat not produce a different arrangement'of the causes an evolution of oxygen from the atoms, because they are already disposed in peroxide, and the manganic and hyperman- the simplest form in which it is possible for ganic acids cannot be separated from their them to combine. Now, let us compare the bases without undergoing immediate decom- composition of sugar of grapes with' the position. - above: here 12 eq. of carbon, 12 eq. of There are many facts which prove, that hydrogen, and 12 eq. of oxygen, are united the most simple inorganic compounds are together, and we know that they are capaalso the most stable, and undergo decompo- ble of combining with each other in the sition with the greatest difficulty, whilst most various ways. From the formula of those which are of a complex composition sugar we might consider it either as a hyyield easily to changes and decompositions. drate of carbon, wood, starch, or sugar of The cause of this'evidently is, that in pro- milk, or farther, as a compound of ether portion to the number of atoms which enter with alchohol or of formic acid with sachulinto a compound, the directions in which min.? Indeed we may calculate alnost all their attractions act will be more numerous. the known' organic compounds destitute of Whatever ideas we may entertain regard- nitrogen from sugar, by simply adding the ing the infinite divisibility'of matter in elements of water, or by replacing any one general, the existence of. chemical propor- of its elementary constituents by a different tions removes every doubt respecting the pre- substance. The elements necessary to form sence of certain limited groups or masses of these compounds are therefore contained in matterwhich we have not thepower of divid- the sugar, and they must also possess the ing. The particles of matter called equiva- power of forming numerous combinations lents in chemistry are not infinitely small, for amongst themselves by their mutual attracthey possess a weight, and are capable of tions. arranging themselves in the most various Now, when we examine what changes ways, and of thus forming innumerable sugar undergoes when brought into contact compound atoms. The properties of these with other bodies which exercise a marked compound atoms differ in organic nature, not only according to the form, but also in'* The black precipitate obtained by the action many instances according to the direction of hydrochloric acid on sugar. 92 AGRICULTURAL CHEMISTRY.' influence upon it, we find, that these changes combined, to undergo the same decomposiare not confined to any narrow limits, like tion, although they exert no chemical afthose of inorganic bodies, but are in fact finity or attraction for them or their constiunlimited.' tuents. The cause which produces these The elements of sugar yield to every at- phenomena will be also recognised, by attraction, and to each in a peculiar manner. tentive observation, in those matters which In inorganic compounds, an acid acts upon excite fermentation or putrefaction. All a particular constituent of the body, which bodies in the act of combination or decomit decomposes, by virtue of its affinity for position have the property of inducing those that constituent, and never resigns its proper processes; or, in other words, of causing a chemical character, in whatever form it may disturbance of the statical equilibrium in be applied. But when it acts upon sugar, the attractions of the elements of complex and induces great changes in that compound, organic molecules, in consequence of which it does this not by any superior affinity for those elements group themselves anew, aca base existing in the sugar, but by disturb- cording to their special affinities. ing the equilibrium in the mutual attraction The proofs of the existence of this cause of the'elements of the sugar amongst them, of action can be easily produced; they are selves. Muriatic and sulphuric acids, which found in the characters of the bodies which.differ so much from one another both in effect fermentation and putrefaction, and in characters and composition, act in the same the regularity with which the distribution manner upon sugar. But the action of both of the elements takes place in the subsevaries according to the state in which they quent transformations. This regularity de-. are; thus they act in one way when dilute, pends exclusively on the unequal affinity in another when concentrated, and even dif- which they possessfor each other in an ferences in their temperature cause a: change isolated condition. The action of water on in their action. Thus sulphuric acid of a wood, charcoal, and cyanogen, the simplest moderate degree of concentration converts of the compounds of nitrogen, suffices to ilsugar into a black carbonaceous matter, lustrate the whole of the transformations of forming at the same time acetic and formic organic bodies; of those in which nitrogen acids. But when the acid is more diluted, is a constituent, and of those in which it is the sugar is converted into two brown sub- absent. stances, both of them containing carbon and the elements of water. Again, when sugar is subjected to the action of alkalies, a whole series of different new products are obtained; while oxidizing agents such as nitric acid, CHAPTER IV. produce from it carbonic acid, acetic acid, oxalic acid, formic, acid, and many other ON THE TRANSFORMATION OF BODIES WHICH products which have not yet been examined. DO NOT CONTAIN NITROGEN AS A CONSTIIf from the facts here stated we estimate TUENT, AND OF THOSE IN WHICH IT IS the power with which the elements of sugar PRESENT. are united together, and judge of the force of their attraction by the resistance which WHEN oxygen and hydrogen combined they offer to the action Qf bodies brought in equal equivalents, as in steam, are coninto contact with them, we must regard the ducted over charcoal, heated to the tempeatom of sugar as belonging to that class of rature at which it possesses the power to compound atoms, which exist only by the enter into combination with one of these vis inertice of their elements. Its elements elements, a decomposition of steam ensues. seem merely to retain passively the position An oxide of carbon (either carbonic oxide and condition in which they had been or carbonic acid) is under all circumstances placed, for we do not observe that they re- formed, while the hydrogen of the water is sist a change of this condition by their own liberated, or, if the temperature be sufficient, mutual attraction, as is the case with sul- unites with the carbon, forming carburetted phate of potash. hydrogen. Accordingly, the carbon is shared Now it is only such combinations as between the elements of the water, the oxysugar, combinations therefore which possess gen and hydrogen. Now a participation of a very complex molecule, which are capa- this kind, but even more complete, is obble of undergoing the decompositions named served in every transformation, whatever fermentation and putrefaction. be the nature of the causes by which it is We have seen that metals acquire a power effected. which they do not of themselves possess, Acetic and meconic" acids suffer a true namely, that of decomposing water and transformation under the influence of heat, nitric acid, by simple contact with other that is, their component elements are dismetals in the act of chemical combination. united, and form new compounds without We have also seen, that peroxide of hydro. any of them being singly disengaged. Acetic gen and the persulphuret of the same ele- acid is converted into acetone and carbonic ment, in the act of decomposition, cause other compounds of a similar kind, but of * An acid existing in opium, and named from which the elements are amuch more strongly the Greek for poppy. CHEMICAL TRANSFORMATIONS. 93 acid (C4 H3 03=C3 H3 O+C02,) and ON THE TRANSFORMATION OF AODIES CONmeconic acid into carbonic acid and kome- TAINING NITROGEN. nic acid; whilst by the influence of a higher temperature, the latter is further decomposed When those substances are examined into pyromeconic acid and carbonic acid. which are most prone to fermentation and Now in these cases the carbon of the bo- putrefaction, it is found that they are all, dies decomposed is shared between the oxy- without exception, bodies which contain gen and the hydrogen; part of it unites with nitrogen. In many of these compounds, a the oxygen and forms carbonic acid, whilst transposition of their elements occurs sponthe other portion enters into combination taneously as soon as they cease to form part with the hydrogen, and an oxide of a carbo- of a living organism; that is, when they are hydrogen is formed, in which all the hy- drawn out of the sphere of attraction in drogen is contained. which alone they are able to exist. In a similar manner, when alcohol is There are, indeed, bodies destitute of niexposed to a gentle red heat, its carbon is trogen, which possess a certain degree of shared between the elements of the water- stability only when in combination, but an oxide of a carbo-hydrogen which con- which are unknown in an isolated condition, tains all the oxygen, and -some gaseous cornm- because their elements, freed from the power pounds of carbon and hydrogen being pro- by which they were held together, arrange duced. themselves according to their own natural It is evident that'during transformations attractions. Hypermanganic, maganic, and caused by heat, no foreign affinities can be hyposulphurous acids, belong to this class in play,:so that the new compounds must of substances, which however are rare. result merely from the elements arranging The case is very different with azotised themselves, according to the degree of their bodies. It would appear that there is some mutual affinities, into new combinations peculiarity in the nature of nitrogen, which which are constant and unchangeable in gives its compounds the power to decorthe conditions under which they were origi- pose spontaneously with so much facility. nally formed, but undergo changes when Now, nitrogen is known to be the most inthese conditions become different. If we different of all the elements; it evinces no compare the products of two bodies, similar particular attraction to any one of the simple in composition but different in properties, bodies; and this character it preserves in all which are subjected to transformations by its combinations, a character which explains two different causes, we find that the man- the cause of its easy separation from the ner, in which the atoms are transposed, is. matters with which it is united. absolutely the same in both. It is only when the quantity of nitrogen In the transformation of wood in marshy exceeds a certain limit, that azotised comsoils, by what we call putrefaction, its car- pounds have some degree of permanence, as bon is shared between the oxygen and hy- is the case with melamin, ammelin, &c. drogen of its own substance, and of the Their liability to change is also diminished, water-carburetted hydrogen is consequently when the quantity of nitrogen is very small evolved, as well as carbonic acid, both of in proportion to that of the other elements which compounds have an analogous corn- with, which it is united, so that their mutual position (CH2, C02.) attractions preponderate. Thus also in that transformation of sugar, This easy transposition of atoms is best which is called fermentation, its elements seen in the fulminating silvers, in fulmiare divided into two portions; the one, car- nating mercury, in the iodide or chloride of bonic acid, which contains i of the oxygen nitrogen, and in all fulminating compounds. of sugar; and the other, alcohol, which con- All other azotised substances acquire the tains all its hydrogen., same power of decomposition, when the In the transformation of acetic acid pro- elements of water are brought into play; duced by a red heat, carbonic acid, which and indeed, the greater part of them are not contains 2-3 of the oxygen of the acetic acid, capable of transformation, while this necesis formed, and acetone, which contains all sary condition to the transposition of their its hydrogen. atoms is absent. Even tle conlpoundsof niIt is evident from these facts, that the ele- trogen, which are most. liable, to change, ments of a complex compound are left to such as those which are found in animal their special attractions whenever their equi- bodies, do not enter into a state of putrefaclibrium is disturbed, from whatever cause faction when dry. this disturbance may proceed. It appears The result of the known transformations also, that the subsequent distribution of the of azotised substances proves that the water elements, so as to form new combinations, does not merely act'as a medium in which always takes place in the same way, with motion is permitted to the elements in the this diflerence only, that the nature of the act of transposition, but that its influence products formed is dependent upon the num- depends on chemical affinity. When the ber of atoms of the elements. which enter decomposition of such substances is effected into action; or, in other words, that the pro- with the assistance of water, their nitrogen ducts differ ad infinitum, according to the is invariably liberated in the form of ammocomposition of the original substance, nia. This is a fixed rule without any excep. 94 AGRICULTURAL CHEMISTRY. tions, whatever may be the cause which being converted into carbonic acid and am, produces the decompositions. All organic monia, with brisk effervescence. compounds containing nitrogen, evolve the This decomposition may be considered as whole of that element in the form of ammo- the type of the transformations of all azonia when acted on by alkalies. Acids, and tised compounds; it is putrefaction in its increase of temperature, produce the same simplest and most perfect form, because the effect. It is only when there is a defi- new products, the carbonic acid and ammociency of water or its elements, that cyno- nia are incapable of further transformations. gen or other azotised compounds are pro- Putrefaction assumes a totally different duced. and much more complicated form, when the From these facts it may be concluded, products, which are first formed undergo athat ammonia is the most stable compound further change. In these cases the process of nitrogen; and that hydrogen and nitro- consists of several stages, of which it is imgen possess a degree of affinity for each possible to determine when one ceases and other surpassing the attraction of the latter the other begins. body for any other element. The transformations of cyanogen, a body Already in considering the transforma- composed of carbon and nitrogen, and the tions of substances destitute of nitrogen, we simplest of all the compounds of nitrogen, have recognised the great affinity of carbon will convey a clear idea of the great variety for oxygen as a powerful cause for effecting of products which are produced in such a the disunion of the elements of a complex case: it is the only example of the putrefacorganic atom in a definite manner. But car-'tion of an azotised body which has been at bon is also invariably contained in azotised all accurately studied. organic compounds, while the great affinity A solution of cyanogen in water becomes of nitrogen for hydrogen furnishes a new turbid after a short time, and deposits a and powerful cause, facilitating the transpo- black, or brownish black matter, which is a sition of their component parts. Thus, in combination of ammonia with another body, the bodies which do not contain nitrogen we produced by the simple union of cvanogenr have one element, and in those in which with water. This substance is insoluble in that substance is present, two elements,- water, and is thus enabled to resist further which mutually share- the elements of water. change. Hence there are two opposite affinities at A second transformation is effected bv the play, which mutually strengthen each other's eyanogen being snared between the elements actions. of the water,, in consequence of which Now we know, that the most powerful cyanic acid is formed by a certain quantity attractions may be overcome by'the influ- of the cyanogen combining,with the oxygen ence of two affinities. Thus, a decomposi- of the water, while hydrocyanic acid is also tion of alumina may be effected with the formed by another portion of the cyanogen greatest facility, when the affinity of char- uniting with the hydrogen which was libecoal for oxygen, and of chlorine for alumi- rated. nium, are both put in action, although nei- Cyanogen experiences a third transformather of these alone has any influence upon tion, by which a complete disunion of its it. There is in the nature and constitution elements takes place, these being divided beof the compounds of nitrogen a kind of ten- tween the constituents of the water. Oxasion of their component parts, and a strong lie acid is the one product of this disunion, disposition to yield to transformations, which and ammonia the other. effect spontaneously the transposition of Cyanic acid, the formation of which has their atoms on the instant that water or been mentioned above, cannot exist in conits elements are brought in contact with tact with water, being decomposed immedithern. ately into carbonic acid and ammonia. The The characters of the hydrated cyanic cyanic acid, however, newly formed in the acid, one of the simplest of all the com- decomposition of cyanogen, escapes this depounds of nitrogen, are perhaps the best composition by entering into combination adapted to convey a distinct idea of the with the free ammonia, by which urea is manner in which the.atoms are disposed of produced. in transformations. This acid contains ni- The hydrocyanic acid is also decomposed trogen, hydrogen, and oxygen, in such pro- into a brown matter which contains hydroportions. that the addition of a certain quan- gen and cyanogen, the latter in greater protity of the elements of Water is exactly suffi- portion than it does in the gaseous state. cient to cause the oxygen contained in the Oxalic acid, urea, and carbonic acid, are also water and acid to unite with the carbon and formed by its decomposition, andformic acid form carbonic acid, and the hydrogen of the and ammonia are produced by the decompowater to combine with the nitrogen and sition of its radical. form ammonia. The most favourable con- Thus, a substance into the composition ditions for a complete transformation are, of which only two elements (carbon and therefore, associated in these bodies, and it nitrogen) enter, yields eight totally different is well known, that the disunion takes place products. Several of these products are on the instant in which the cyanic acid and formed by the transformation of the original water ate brought into contact, the mixture body, its elements being shared between the Ce E MICAL TRA NSFORMATJIONS. 95 conlstituents of water; others are produced fore, 103.89 parts of carbonic acid and alcoin consequence of a further disunion of hol. The entire carbon in these products is those first formed. The urea and carbonate equal to 42 parts, which is exactly the quanof ammonia are generated by the combina- tity originally contained in the sugar. tion of two of the products, and in their for- The analysis of sugar from the cane, mation the whole of the elements have as- proves that it contains the elements of carsisted. bonic acid and alcohol, minus 1 atom of These examples showv, that the results of water. The alcohol and carbonic acid prodecomposition by fermentation or putrefac- duced by the fermentation of a certain quantion comprehend very different phenomena. tity of sugar, contain together one equivalent The first kind of transformation is, the of oxygen and one equivalent of hydrogen, transposition of the elements of one complex the elements, therefore, of one equivalent compound, by which new compounds are of water, mnore than the sugar contained. produced with or without the assistance of The excess of weight in the products is the elements of water. In the products thus explained most satisfactorily; it is ow — newly formed in this manner, either the ing, namely, to the elements of water haysame proportions of those component parts ing taken part in the metamorphosis of the which were contained in the matter before sugar. transformation, are found, or with them, an It is known that 1 atom of'sugar contains excess, consisting of the constituents of wa- 12 equivalents of carbon, both from the ter which had assisted in promoting the dis- proportions in which it unites with bases, union of the elements. and from the composition of saccharic acid The second kind of transformation con- the product of its oxidation. Now none of sists of the transpositions of the atoms of these atoms of carbon are contained in the two or more complex compounds, bywhich sugar as carbonic acid, because the whole the elements of both arrange themselves quantity is obtained as' oxalic acid, when mutually into new products, with or with- sugar is treated with hypermanganlate of out the co-operation of the elements- of wa- potash (Gregory ) and as oxalic acid is a ter. In this kind of transformations, the lower degree of the oxidation of carbon than new products contain the sum of the con- carbonic acid, it is impossible to conceive stituents of all thle compounds which had that the lower degree should be produced taken a part in the decornposition. from the higher, by means of one of the The first of these two modes of decom- most powerful agents of oxidation which position is that designatedfernentcation, the we possess. second putrefaction; and when these terms It can be also proved, that the hydrogen are used in the following pages, it will of the sugar does not exist in it in the form always be to distinguish the two processes of alcohol, for it is converted into water above described, which are so different in and a kind of carbonaceous matter, when their results. treated with acids, particularly with such as contain no oxygen; and this manner of decomposition is never suffered by a compound of alcohol. CHAPTER; V. Sugar contains, therefore, neither alcohol nor carbonic acid, so that these bodies must FERMENTATION OF SUGAR. be produced by a different arrangement of its atoms, and by their union with the elements THE peculiar decomposition which sugar of water. suffers may be viewed as a type of all the In this metamorphosis of sugar, the eIetransformations designated ferm.entation. ments of the yeast, by contact with which Thr nard obtained from 100 grammes of its fermentation was effected, take no apprecane-sugar 0.5262 of absolute alcohol. 100 ciable part in the transposition of the eleparts of sugar from the cane yield, there- ments of the sugar; for in the products resulting from theaction, we find no component part of this substance. * Wihen'yeast is made into a thin paste with ponent part of this substance. water, and I cubic centimetre of this mixture in- We may now study the fermentation of trodulced into a graduated glass receiver filled with' a vegetable Juice, which contains not only mercury, in which are already 19 grammes of a saccharine mnatter, but also such substances solution of cane sugar, containing 1 gramme of as albumen and gluten. The juices of pure solid sugar; it is found after the mixture has parsneps, beet-roots, and onions, are well been exposed for 24 hours to a temperature of forWhen such a from 20 to 25 C. (68-77 F.,) that a volume of adapted for this purpose. When such a carbonic acid has been formed, which, at Of C. juice is mixed with yeast at common (32' F.) and an atmospheric pressure indicated by temperatures, it ferments like a solution of 0.76 metre Bar. would be from 245 to 250 cubic sugar. Carbonic acid gas escapes from it centimetres. Biut to this quantity we must add 11 with effervescence, and in the liquid, alcohol cubic centimetres of carbonic alcid, with which is'found in quantity exactly corresponding the 11 grammes of liquid would be saturated, so to that of tbe sugar originally contained in that in all 255-259 cubic ceutimetres of carbonic acid are obtained. This volume of carbonic acid the juice. But such a juice undergoes sponcorresponds to from 0.503 to 0.5127 grammes by taneous decomposition at a temperature of weight. from 950 to 1040 (350-~400 C.) Gases 96,A GRICULTURAL CHEMISTRY. possessing an offensive smell are evolved in by the temperature of boiling water, by alConsiderable quantity, and. when the liquor cohol, common salt, an excess of sugar, is examined after the decomposition is cornm- oxide of mercury, corrosive sublimate; pyropleted, no alcohol can be detected. The ligneous acid, sulphurous acid, nitrate of sugar has also disappeared, and with it all silver, volatile oils, and in- short by all antithe azotised compounds which existed in the septic substances. juice previously to its fermentation. Both The insoluble part of the substance called were decomposed at the same time; the nitro- ferment does not cause fermentation. For genofthe azotised compounds remains in the when the yeast from wine or beer is careliquid- as ammoina, and, in addition to it, fully washed with water, care being taken there are three new products, formed from that it is always covered with this fluid, the the component parts of the juice. One of residue does not produce fermentation. these is lactic acid, the slightly volatile con- The soluble pat t of ferment likewise does pound found in the animal organisml; the not excite fermentation. An aqueous infuother is the crystalline body which forms sion of yeast may be mixed with a solution the principal constituent of manna; and the of sugar, and preserved in vessels from which third is a mass resembliig gum-arabic, which the air is excluded, without either experiforms a thick viscous solution with water. encing the slightest change. What then, we These three products weigh more than the may ask, is the matter in ferment which exsugar contained in the juice, even without cites fermentation, if neither the soluble nor calculating the weight of the gaseous pro- insoluble parts possess the power? This ducts. Hence they are not produced from question has been answered by Colin in the the elements of the sugar alone.' None of most satisfactory manner. He has shown these three substances could be detected in that in reality it'is the soluble part. But the juice before fermentation. They must, before it obtains this power, the decanted therefore, have been formed by the inter- infusion must be allowed to cool in contact change of the elements of the sugar with with the. air, and to remain some time exthose of the foreign substances also present. posed to its action. When introduced into It is this mixed transformation of two or a solution of sugar in this state, it produces more compounds which receives the special a brisk fermentation; but without previous name of putrefaction. exposure to the air, it manifests no such property. YEAST OR FERMENT. The infusion absorbs oxygen during its exposure-to the air, and carbonic acid may When attention is directed to the condi- be found in it after a short time. tion of those substances which possess the Yeast produces fermentation in consepower of inducing fermentation and putre- quence of the progressive! -decomposition faction in other bodies, evidences are found which it suffers from the action of air and in their general characters, and in the man- water. ner in which they combine, that they all are Now when yeast is made to act on sugar, bodies, the atoms of which are in the act of it is found, that after the transformation of transposition. the latter substance into carbonic acid and The characters of the remarkable matter alcohol is completed, part of the yeast itself which is deposited in an insoluble state has disappeared. during the fermentation of beer, wine, and From 20 parts of fresh yeast from beer, vegetable juices, may first be studied. and 100 parts of sugar, The'nard obtained, This substance, which has been called after the fermentation was completed, 13-7 yeast or ferment, from the power which it parts of an insoluble residue, which dimipossesses of causing fermentation in sugar, nished to 10 parts when employed in the or saccharine vegetable juices, possesses all same way with a fresh portion of sugar. the characters of a compound of nitrogen in These ten parts were white, possessed of the the state of putrefaction and eremacausis. properties of woody fibre, and had no farther Like wood in the state of eremacausis, action on sugar. yeast converts the oxygen of the surrounding It is evident, therefore, that during the ferair into carbonic acid, but it also evolves this mentation of sugar by yeast, both of these gas from its own mass, like bodies in the substances suffer decomposition at the same state of putrefaction. (Colin.) When kept time, and disappear in consequence. But underwater, it emits carbonic acid, accompa- if yeast be a body which excites fermentanied by gases of an offensive smell, (Thb- tion by being itself in a state of decomposinard,) and is at last converted into a sub- tion, all other matters in the same condition stance resembling old cheese. (Proust.) should have a similar action upon sugar; and But when its own putrefaction is completed, this is in reality the case. Muscle, urine, it has no longer the power of inducing fer- isinglass, osmazome, albumen, cheese, gliamentation in other bodies. The presence dine, gluten, legumin, and blood, when in a of water is quite necessary for sustaining state of putrefaction, have all the power of the properties of ferment, for by simple pres- producing the putrefaction, or fermentation sure its power to excite fermentation is of a solution of sugar. Yeast, which by much diminished, and is completely de- continued washing has entirely lost the prostroyed by drying. Its action is arrested also perty of inducing fermentation, regains it CHEMICAL TRANSFORMATIONS. 97 when its putrefaction has recommenced, in It has already been mentioned, that the consequence of its being kept in a warm strong affinity otf nitrogen for hydrogen, and situation for some time. that of carbon for oxygen, are the cause of, Yeast and putrefying animal and vegeta- the facility with which the elements of azoble matters act as peroxide of hydrogen does tised compounds are disunited; those affinion oxide of silver, when they induce bodies ties aiding each other, inasmuch as by virwith which they are in contact to enter into tue of them different elements of the cornthe same state of decomposition. The dis- pounds strive to take possession of the difturbance in the attraction of the constituents ferent elements of water. Now since it is of the peroxide of hydrogen effects a disturb- found that no body destitute of nitrogen posance in the attraction of the elements of the sesses, when pure, the property of decomoxide of silver, the one being decomposed, posing spontaneously whilst in contact with on account of the decomposition of the water, we must ascribe this property which other. azotised bodies possess in so eminent a deNow if we consider the process of the gree, to something peculiar in the nature of fermentation of pure sugar, in a practical the compounds of nitrogen;, and to their conpoint of view, we meet with two facts of stituting, in a certain measure, more highly constant occurrence. When the quantity organized atoms. of ferment is too small in proportion to that Every azotised constituent of the animal of the sugar, its putrefaction will be com- or vegetable organism runs spontaneously: pleted before the transformation of all the into putrefaction, when exposed to moisture sugar is effected. Some sugar here remains and a high temperature. undecomposed, because the cause of its Azotised matters are, accordingly, the transformation is absent, viz. contact with a only causes of fermentation and putrefaction body in a state of decomposition. in vegetable substances. But when the quantity of ferment pre- Putrefaction, on account of its effects, as dominates, a certain quantity of it remains a mixed transformation of many different after all the sugar has fermented, its decom- substances, may be classed with the most position proceeding very slowly, on account powerful processes of deoxidation, by which of its insolubility in water. This residue the strongest affinities are overcome. of ferment is still able to induce fermentation' When a- solution of gypsum in water is when introduced into a fresh solution of su- mixed with a, decoction of sawdust, or any gar, and retains the same power until it has other organic matter capable of putrefaction, passed through all the stages of its own and preserved in well-closed vessels, it is transformation. Hence a certain quantity found after some time, that the solution conof yeast is necessary in order to effect the tains no more sulphuric acid, but in its transformation of a certain portion of sugar, place carbonic and free hydro-sulphuric not because it acts by its quantity in increas- acid, between which the lime of the gypsum ing any affinity, but because its influence is shared. In stagnant water containing depends solely on its presence, and its pre- sulphates in solution, crystallised pyrites is' sence is necessary, until the last atom of observed to form on the decaying roots. sugar is decomposed. Now we know that in the putrefaction of These facts and observations point out the wood under water, when air therefore is ex-, existence- of a -new cause, which effects cluded, a part of its carbon combines with combinations and decompositions. This the oxygen of the water, as well as with the cause is the action which bodies in a state oxygen which the wood itself contains; of combination or decomposition exercise whilst its hydrogen and that of the deconmupon substances, the component parts of posed water are liberated either in a pure which are united together by a feeble affinity. state, or as carburetted hydrogen. The This action resembles a peculiar power, at- products of this decomposition are of the tached to a body in the state of combination same kind as those generated when steam is or decomposition, but exerting its influence conducted-over red-hot charcoal. beyond the sphere of its own attractions. It is evident, that if with the water a subWe are now able to account satisfactorily stance containing a large quantity of oxygen, for many known phenomena. such as sulphuric acid, be also present, the A large quantity of hippuric acid may be matters in the state of putrefaction will make obtained from the fresh urine of a horse, by use of the oxygen of that substance as well the addition of muriatic acid; but when the as that of the water, in order to form carurine has undergone putrefaction, no trace bonic acid; and the sulphur and hydrogen of it can be discovered. The urine of man being set free will combine whilst in the contains a considerable quantity of urea; nascent state, producing hydrosulphuric but when the urine putrefies, the urea en- acid, which will be again decomposed if tirely disappears. When urea is added to a metallic oxides be, present; and the resu. ts solution of sugar in the state of fermentation, of this second decomposition will be wa:,er it is decomposed into carbonic acid and am- and metallic sulphurets. monia. No asparagin can be detected in a The putrefied leaves of woad (Isatis tincputrefied infusion of asparagin, liquorice- toria,) in contact with indigo-blue, water, root, or the root of marshmallow (.lPthwea and alkalies, suffer farther decomposition, officinalis. and the indigo is deoxidised and dissolved. 13 I 98 AGRICULTURAL CHEMISTRY. The mannite formed by the putrefaction and properties, during which oxygen is ab of beet-roots and other plants which contain sorbed. These changes do not take place sugar, contains the same number of equiva- when water is excluded, or when the subtents of carbon and hydrogen as the sugar stances are exposed to the temperature of of grapes, but two atoms less of oxygen; 320, and it has been observed that different and it is highly probable that it is produced bodies require different degrees of heat, in from sugar of grapes, contained in those order to effect the absorption of oxygen, plants, in precisely the same manner as in- and, consequently, their eremacausis. The digo-blue is converted into deoxidised white property of suffering this change. is posindigo. sessed in the highest degree by substances During the putrefaction of gluten, car- containing nitrogen. bonic acid and pure hydrogen gas are When vegetable juices are evaporated by evolved; phosphate, acetate, caseate, and a gentle heat in the air, a brown or brownlaItate of ammonia being at the same time ish-black substance is precipitated as a proproduced in such quantity, that the further duct of the action of oxygen upon them. decomposition of the gluten ceases. But- This substance, which appears to possess when the supply of water is renewed, the similar properties from whatever juice it is decomposition begins again, and in addition obtained, has received the name of extractive to the salts just mentioned, carbonate of am- matter; it is insoluble or very sparingly monia and a white crystalline matter re- soluble in water, but is dissolved with facilsembling mica (caseous oxide) are formed, ity by alkalies. By the action of air on together with hydrosulphate of ammonia, solid animal or vegetable matters, a similar and a mucilaginous substance coagulable pulverulent brown substance is formed, and bv chlorine. Lactic acid is almost always is known by the name of humuls. produced by the putrefaction of organiic The conditions which determine the cornbodies. mencement of eremacausis are of various We may now compare fermentation and kinds. Many organic substances, particuputrefaction with the decomposition which larly such as are mixtures of several more organic compounds suffer under the influ- simple mnatters, oxidise in the air when ence of a high temperature. Dry distilla- simply moistened with water; others not tion would appear to be a process of com- until they are subjected to the action of albustion or oxidation going on, in the interior kalies; but the greatest part of them undergo of a substance, in which a part of the car- this state of slow combustion or oxidation, bon unites with all or part of the oxygen of when brought in contact with other decaythe compound, while other new compounds'ing matters. containing a large proportion of hydrogen The eremacausis of an organic matter is are necessarily produced. Fermentation retarded or completely arrested by all those may be considered as a process of combus- substances which prevent fermentation or tion or oxidation of a similar kind, taking putrefaction. Mineral acids, salts of merplace in a liquid between the elements of cury, aromatic substances, empyreumatic the same matter, at a very slightly elevated oils, and oil of turpentine, possess a simitemperature; and putrefaction as a process lar action in this respect. The latter subofioxidation, in which the oxygen of all the stances have the same effect on decaying substances present comes into play. bodies as on phosphuretted hydrogen, the spontaneous inflammability of which they destroy. Many bodies which do not decay when moistened with water, enter into eremacausis when in contact with an alkali. Gallic EREMACAUSIS, OR DECAY. acid, hoematln, and many other compounds, may be dissolved in water and yet remain IN organic nature, besides the processes unaltered; but if the smallest quantity of a of decomposition named fermentation and free alkali is present, they acquire the proputrefaction, another and not less striking perty of attracting oxygen, and are conclass of changes occurs, which bodies suf- verted into a brown substance like humus, fer from the influence of the air. This is evolving very frequently at the same time the act of gradual combination of the com- carbonic acid. (Chevreul.) bustible elements of a body with the oxygen A very remarkable kind of eremacausls of the air; a slow combustion or oxidation, takes place in many vegetable substances, to which we shall apply the term of ere- when they are exposed to the influence of macausis. air,, water, and ammonia. They absorb The conversion of wood into humus, the oxygen very rapidly, and form splendid formation of acetic acid out of alcohol, ni- violet or red-coloured liquids, as in the case trification, and numerous other processes, of orcin and erythrin. They now contain are of this nature. Vegetable juices of an azotised substance, not in the form of every kind, parts of animal and vegetable ammonia. substances, moist sawdust, blood, &c., can- All these facts show that the action of not be exposed to the air, without suffering oxygen seldom affects the carbon of decayimmediately a progressive change of colour ing substances, and this corresponds exactly EREMACAUSIS OR DECAY. 99.o what happens in combustion at high tern- But, although it appears very probable peratures. It is well known, for example, that the oxygen acts primarily and princithat when no more oxygen is admitted to a pally upon hydrogen, the most combustible compound of carbon and hydrogen than is constituent of organic matter in the state of sufficient to combine with its hydrogen, the decay; still it cannot thence be concluded carbon is not burned, but is separated as that the carbon is quite devoid of the power lamp-black; while, if the quantity of oxygen to unite.with oxygen, when every particle is not sufficient even to consume all the hy- of it is surrounded with hydrogen,; an eledrogen, new compounds are formed, such ment with which the oxygen combines with as naphthalin and similar matters, which greater facility. contain a smaller proportion of hydrogen We know, on the contrary, that althoughll than those compounds of carbon and hydro- nitrogen cannot be made to combine with gen which previously existed in the com- oxygen directly, yet it is oxidized and forms bustible substance. nitric acid, when mixed with a large quan.There is no example of carbon combining tity of hydrogen, and burned in oxygen gas. directly with oxygen at common tempera- In this case its affinity is evidently increased tures, but numerous facts show that hydro- by the combustion of the hydrogen, which gen, in certain states of condensation, pos- is in fact communicated to it. It is consesses that property. Lamp-black which ceivable, that in a similar manner, the carhas been heated to redness may be kept in bon maybe directly oxidised in several cases, contact with oxygen gas, without forming obtaining from its contact with hydrogen in carbonic acid; but lamp-black, impregnated eremacausis a property which it does not with oils which contain a large proportion itself possess at common temperatures. But of hydrogen, gradually becomes warm, and the formation of carbonic acid during the inflames spontaneously. The spontaneous eremacausis of bodies containing hydrogen, inflammability of the charcoal used in the must in most cases be ascribed to another fabrication of gunpowder has been correctly cause. It appears to be formed in a man-,.ascribed to the hydrogen which it contains ner similar to the formation of acetic acid, in considerable quantity; for during its re. by the eremacausis of saliculite of potash.* duction to powder, no trace of carbonic acid An alkaline solution of -hematin being can be detected in the air surrounding it; it exposed to an atmosphere of oxygen, 0-2 is not formed until the temperature of the grm. absorb 28'6 cubic centimetres of oxymass has reached a red heat. The heat gen gas in twenty-four hours, the alkali acwhich produces the inflammation is there- quiring at the same time 6 cubic centimetres fore not caused by the oxidation of the car- of carbonic acid. (Chevreul.)- But these bon. 6 cubic centimetres of carbonic acid contain The substances which undergo erema- only an equal volume of oxygen, so that it causis may be divided into two classes. The is certain from this experiment that 4 of the first class comprehends those substances oxygen absorbed have not united with the which unite with the oxygen of the air, carbon. It is. highly probable, that during without evolving carbonic acid; and the the oxidation of the hydrogen, a portion of second, such as emit carbonic acid by ab- the carbon had united with the oxygen consorbing oxygen. tained in the hwematin, and -had separated When tne oil of bitter almonds is exposed from the other elements as carbonic acid. to the air, it absorbs two equivalents of,The experiments of De Saussure upon oxygen, and is converted into benzoic acid; the decay of woody fibre show that such a but half of the oxygen absorbed combines separation is quite possible. Moist woody with the hydrogen of the oil, and forms fibre evolved one volume of carbonic acid water, which remains in union with the for every volume of'oxygen which it abanhydrous benzoic acid., sorbed. It has just been mentioned that carbonic acid contains its own volume of * According to the experiments of Dobereiner, oxygen. Now, woody fibre contains carbon 100 parts of pyrogallic acid absorbs 38'09 parts of' and the elements of water, so that the result, oxygen when in contact with ammonia'and water; of the action of oxygen upon it is exactly the acid being changed in consequence of this ab- the same as if pure charcoal had combined sorption into a mouldy substance, which contains less oxygen than the acid itself. It is evident that directly with oxygen. But the characters the substance which is formed is not a higher of woody fibre show, that the elements of oxide; and it is found, on comparing the quantity water are not.contained in it in the form of of, the oxygen absorbed with that of' the hydrogen water; for, were this the case, starch, sugar, contained in the acid, that they are exactly in the and gum must also be considered as hydrates proportions for forming water., When colourless orcin is exposed together withof carbon. ammonia to the contact of oxygen gas, the beau. tiful red-coloured orcein is produced. Now, the In this case it is evident, that the oxygen absorbed only changes which take place kere are, that the has united merely with the hydrogen. absorption of oxygen by the elements of orcin This salt, when exposed to a moist atmoand ammonia causes the'formation of water; 1 sphere, absorbs 3 atoms of oxygen; melanic acid equivalent of orcin C18 H112 08, and 1 equivalent is produced, a body resembling humus, in conseof ammonia NH3, absorb 5 equivalents of oxygen, quence of the formation of which,'the elements and 5 equivalents of water are produced, the com- of 1 atom of acetic acid are separated from the position of orcin being'!8 H10 08 N. (Dumas.) saliculous acid. 100 AGRICULTURAL CHEMISTRY. But if the hydrogen does not exist in dent that phosphorus and hydrogen are woody fibre in the form of water, the direct more combustible than charcoal, that is, that oxidation of the carbon cannot be considered their affinity for oxygen at conmon temperaas at all probable, without rejecting all the tures is greater; and this is not the less cerfacts established by experiment regarding tain, because it is found, that carbon in certhe process of combustion at low tempera- tain other conditions shows a much greater tures. affinity for oxygen than either of those subIf we examine the action of oxygen upon stances. a substance containing a large quantity of In putrefaction, the conditions are evihydrogen, such as alcohol, we find most dently present, under which the affinity of distinctly, that the direct formation of car- carbon for oxygen comes into play; neither bonic acid is the last stage of its oxidation, expansion, cohesion, nor the gaseous state, and thatit is preceded by a series of changes, opposes it, whilst in eremacausis all these the last of which is a complete combustion restraints have to be overcome. of the hydrogen. Aldehyde, acetic, formic, The evolution of carbonic acid, during oxalic, and carbonic acids, form a connected the decay or eremacausis of animal or vegechain of products arising from the oxidation table bodies which are rich in hydrogen, of alcohol; and the successive changes must accordinglybe ascribed to a transposiwhich this fluid experiences from the action tion of the elements or disturbance in their of oxygen may be readily traced, in them. attractions, similar to that which gives rise Aldehyde is alcohol minus hydrogen; acetic to the formation of carbonic acid in the proacid is formed by the direct union of ailde- cesses of fermentation and putrefaction. hyde with oxygen. Formic acid and water The eremacausis of such substances is, are formed by the union of acetic acid with therefore, a decomposition analogous to the oxygen. When all the hydrogen is removed putrefaction of azotised bodies. For in these from this formic acid, oxalic acid is pro- there are two affinities at play; the affinity duced; and the latter acid is converted into of nitrogen for hydrogen, and that of carbon carbonic acid by uniting with an additional for oxygen, and both facilitate the disunion portion of'oxygen. All these products of the elements. Now there are two affiniappear to be formed simultaneously, by the ties also in action in those bodies which deaction of oxidising agents on alcohol; but cay with the evolution of carbonic" acid. it can scarcely be doubted, that the forma- One of these affinities is the attraction of the tion of the last product, the carbonic acid, oxygen of the air for the hydrogen of -the does not take place until all the hydrogen substance, which corresponds to the attrachas been abstracted. tion of nitrogen for the same element; and The absorption of oxygen by drying oils the other is the affinity of the carbon of the certainly does not depend upon the oxida- substance for its oxygen, which is constant tion of their carbon; for in raw nut-oll, for under all circumstances. example, which was not free from mucilage When wood putrefies in marshes, carbon and other substances, only twenty-one vo- and oxygen are separated from its elements lumes of carbonic acid were formed for in the form of carbonic acid, and hydrogen every 146 volumes of oxygen gas absorbed. in the form of carburetted hydrogen. But It must be remembered, that combustion when wood decays or putrefies in the air, or oxidation at low temperatures produces its hydrogen does not combine with carbon, results quite similar to combustion at high; but with oxygen, for which it has a much temperatures with limited access of air. The greater affinity at common temperatures. most combustible element of a compound, Now it is evident from the complete simiwhich is exposed to the action of oxygen, larity of these processes, that decaying and must become oxidised first, for its superior putrefying bodies can mutually replace one combustibility is caused by its being enabled another in their reciprocal actions. to unite with oxygen at a temperature at All putrefying bodies pass into the state which the other elements cannot enter into of decay, when exposed freely to the air, that combination; this property having the and all decaying matters into that of putresame effect as a greater affinity. faction when air is excluded. All bodies, The combustibility of potassium is no likewise, in a state of decay are capable of measure for its affinity for oxygen; we have inducing putrefaction in other bodies in the reason to believe that the attraction of mag- same manner as putrefying bodies themnneslum and aluminium for oxygen is greater selves do. than that of potassium for the same element; but neither of those metals oxidises either in air or water at common temperatures, whilst potassium decomposes water with CHAPTER VII. great violence, and appropriates its oxygen. Phosphorus and hydrogen combine with EREMACAUSIS OR DECAY OF BODIES DESTIoxygen at ordinary temperatures, the first TUTE OF NITROGEN: FORMATION OF ACETIO in moist air, the second when in contact ACID. with finely-divided platinum; while charcoal requires a red heat before it can enter. ALL those substances which appear to into combination witch oxygen. It is evi- possess the property of entering spontane EREMACAUSIS OR DECAY. 101 ously Into fermentation and putrefaction, do oxygen. The oxygen acts here in a similar not in reality suffer those changes without manner to the friction or motion which afsome previous disturbance in the attraction fects the mutual decomposition of two salts,of their elements. Eremacausis always pre- the crystallization of salts fromtheir solution, cedes fermentation and putrefaction, and it or the explosion of fulminating mercury. It is'not until after the absorption of a certain causes the state of rest to be converted into quantity of oxygen that the -signs. of a trans- a state of motion. formation in the interior of the substances When this condition of intestine motion show themselves. is once'excited, the presence of oxygen is It is a very general error to suppose that no longer necessary. The smallest particle organic substances have the power of un- of an azotised body in this act of decompodergoing change spontaneously, without the sition exercises an influence upon the partiaid of an external cause. When they are tides in contact with it, and the state of not in a state of change, it is necessary, be- motion is thus propagated through the subfore they can assume that state, that the stance. The air may now be completely existing equilibrium of their elements should excluded, but the fermentation or putrefacbe disturbed; and the most common cause tion proceeds uninterruptedly to its compleof this disturbance is undoubtedly the atmo- tion. It has been remarked that the mere sphere which surrounds all bodies. contact of carbonic acid issufficient to proThe juices of the fruit or other part of a duce fermentation in the juices of several plant which very readily undergo decompo- fruits. sition, retain their properties unchanged as The contact of ammonia and alkalies in long as they are protected from immediate general may be mentioned' amongst the contact with the air, that is, as long as the chemical conditions which determine the cells or organs in which they are contained commencement of eremacausis; for their resist the influence of the air. It is not presence causes many substances to absorb until after the juices havebeen exposed to oxygen and to decay, in which neither oxythe air, and have absorbed a certain quan-.gen nor alkalies alone produce that change. tity of cxygen, that the substances dissolved Thus alcohol does not combine with the in them begin to be decomposed. oxygen of the air at common temperatures. The beautiful experiments of Gay-Lussac But a solution of potash in alcohol absorbs upon the fermentation of the juice of grapes, oxygen with much rapidity, and acquires a as well as the important practical improve- brown colour. The alcohol is found after a. ments to which they have led, are the best short time to contain acetic acid, formic acid, proofs that the atmosphere possesses an in- and the products of the decomposition of fluence upon the changes of organic sub- aldehyde by alkalies, including aldehyde stances. The juice of grapes which were resin, which gives the liquid a brown colour. expressed under a receiver filled with mer- The most general condition for the proCury, so that air was completely excluded, duction of eremacausis in organic matter is did not ferment. But when the smallest contact with a body already in the state of portion of air was introduced, a certain eremacausis or putrefaction. We have here quantity of oxygen became absorbed, and an instance of true contagion; for the comfermentation immediately began. Although munication of the state of combustion is in the juice was expressed from the grapes in reality the effect-of the contact. contact with air, under the conditions there- It is decaying wood which causes fresh fore necessary to cause its fermentation, still wood around it to assume the same condithis change did not ensue when the juice tion, and it is the very finely divided woody was heated in close vessels to the tempera- fibre in the act of decay which in moistened ture of boiling water. When thus treated, gall-nuts converts the tannic acid with such it could, be preserved for years without rapidity into gallic acid. losing its property of fermenting. A fresh A most remarkable and decided -example exposure to the air at any period caused it of this induction of combustion has been to ferment. observed by De Saussure. It has already Animal food of every kind; and even the been mentioned, that'moist woody fibre, most delicate vegetables, may be preserved cotton, silk, or vegetable mould, in the act unchanged if heated to the temperature of of fermentation or putrefaction, converts boiling water in vessels from which the air oxygen gas which may surround it into caris completely excluded. Food thus pre- bonic acid, without change of volume. Now, pared has been kept for fifteen'years, and De Saussure added a certain quantity of hyupon opening the vessels after this long drogen gas to the oxygen, and observed a time, has been found as fresh and well-fla- diminution in volume immediately after the voured as when originally placed in them. addition. A part of the hydrogen gas had The action of the oxygen in these pro- disappeared, and along with it a portion of cesses of decomposition is very simple; it the oxygen, hut a corresponding quantity excites changes in the composition of the of carbonic acid gas had not been formed. azotised matters dissolved in the juices;- The hydrogen and oxygen had disappeared the mode of combination of the elements of in exactly the same proportion as that in those matters undergoes a disturbance and which they combine to form water; a true change in consequence of their contact with combustion of the hydrogen, therefore, had 2 102 AGRICULTURAL CHEMISTRY. been induced by mere contact with matter CHAPTER VIII. ~in the state of eremacausis. iThe action of the decaying substance here produced results EREM.CAUSIS OF SUBSTANCES CONTAINING exactly similar to those effected by spongy NITROGEN. NITRIFICATION. platinum; but that they proceeded from a different cause was shown by the fact, that WHEN azotised substances are burned at the presence of carbonic oxide, which ar- high temperatures, their nitrogen does not'rests completely the action of platinum enter into direct combination with oxygen. on carburetted hydrogen, did not retard in The knowledge of this fact is of assistance the slightest degree the combustion of in considering the process of the eremacauthe hydrogen in contact with the decaying sis of such substances. Azotised organic bodies. - matter always contains carbon and hydroBut the same bodies were found by De gen, both of which elements have a very Saussure not to possess the property just strong affinity for oxygen. described, before they were in a state of fer- Now nitrogen possesses a very feeble mentation or decay; and he has shown that affinity for that element, so that its comeven when they are in this state, the pre- pounds during their combustion present' sence of antiseptic matter destroys com- analogous phenomena to those which are pletely all their influence. observed in the combustion of substances Let us suppose a volatile substance con- containing a large proportion of hydrogen taining a large quantity of hydrogen to be and carbon; a separation of the carbon of substituted for the hydrogen gas in De Saus- the latter substances in an uncombined state sure's experiments. Now, the hydrogen in takes place, and in the same way the subsuch compounds being contained in a state stances containing nitrogen give out that of greater condensation would suffer a more element in its gaseous form. rapid oxidation, that is, its combustion When a moist azotised animdl matter is would be sooner completed. This principle exposed to the action of the air, ammonia is is in reality attended to in the manufactories always liberated; nitric acid is never formed. in which acetic acid is prepared according But when alkalies or alkaline bases are to the new plan. In the process there present, a union of oxygen with the nitrogen adopted all the conditions are afforded for the takes place under the same circumstances, eremacausis of alcohol, and for its conse- and nitrates are formed together with the quent conversion into acetic acid. other products of oxidation. The alcohol is exposed to a moderate Although we see the most simple means heat, and spread over a very extended sur- and direct methods employed- in the great face, but these conditions are not sufficient processes of decomposition which proceed.to effect its oxidation. The alcohol must be in nature, still we find that the final result mixed with a substance which is with faci- depends on a succession of actions, which lity changed by the oxygen oft the air, and are essentially influenced by the chemical naeither enters into eremacausis by mere con- ture of the bodies submitted to decomposition. tact with oxygen, or by its fermentation or When it is observed that the character of putrefaction yields products possessed of this a substance, remains unaltered in a whole property. A small quantity of beer, aces- series of.phenomena, there is no reason to cent wine, a decoction of malt, honey, and ascribe a new character'to it, for the purnumerous other substances of this kind, pose of explaining a single phenomenon, possess the action desired. especially where the explanation of that acThe difference in the nature of the sub- cording to known facts offers no difficulty. stances which possess this property shows, The most distinguished philosophers supthat none of them can contain a peculiar pose that the nitrogen in an animal submatter which has the property-of exciting stance, when exposed to the action of air, eremacausis; they are only the bearers of an water, and alkaline bases, obtains the power action, the influence of which extends be- to unite directly with oxygen, and form niyond the sphere of its own attractions. tric acid, but we are not acquainted with a Their power consists in a condition of de- single fact which justifies this opinion. It composition or eremacausis, which im- is only by the interposition of a large quanpresses the same condition upon the atoms tity of hydrogen in the state of combustion of alcohol in its vicinity; exactly as in the- or oxidation, that nitrogen can be converted case of an alloy of platinum and silver dis- into an oxide. solving in nitric-acid, in which the platinum When a compound of nitrogen and cai'. becomes oxidised, by virtue of an inductive bon, such as cyanogen, is burned in oxygen action exercised upon it by the silver in the gas, its carbon alone is oxidised; and when act of its oxidation. The hydrogen of the it is conducted over a metallic oxide heated alcohol is oxidised at the expense of the to- redness, an oxide of nitrogen is very oxygen in contact with it, and forms water, rarely produced, and never when the carbon evolving heat at the same time; the residue is in excess. Kuhlmann found in his ex. is aldehyde, a substance which has as great periments, that it was only when cyanogen an affinity for oxygen as sulphuric acid, and was mixed with an excess of oxygen gas combines, therefore, directly with it, produc- and conducted over spongy platinum, that ing acetic acid.. nitric acid was generated. EREMACAUSIS OR DECAY. 103 Kuhlmann could not succeed in causing i form, nitrogen possesses a much greater dispure nitrogen to combine directly with oxy- position to unite with oxygen than it has in gen, even under the most favourable circum- any of its other compounds; we can with stances; thus, with the aid of spongy plati- difficulty resist the conclusion, that ammonum at different temperatures, no union nia is the general cause of nitrification on took place. the surface of the earth. The carbon in the cyanogen gas must, Azotised animal matter is not, therefore, therefore, have _iven rise to the combustion the immediate cause of nitrification, it conof the nitrogen by induction. tributes to the production of nitric acid only On the other hand we find that ammonia in so far as it is a slow and continued source (a compound of hydrogen and nitrogen) of ammonia. cannot be exposed to the action of oxygen, Now it has been shown in the former part without the formation of an oxide of nitro- of this work, that ammonia is always pregen, and in consequence the production of sent in the atmosphere,; so that nitrates nitric acid. might thence be formed in substances which It is owing to the great facility with which themselves contained no azotised matter. It ammonia is converted into nitric acid, that is known also, that porous substances posit is so difficult to obtain a correct determi- sess generally the power of condensing amnation of the quantity of nitrogen in a com- monia; there are few ferruginous earths pound subjected to analysis, in which it is which do not evolve ammoniacal products either contained in the form of ammonia, or when heated to redness, and ammonia is the from which ammonia is formed by an eleva- cause of the peculiar smell perceived upon tion of temperature. For when ammonia is moistening aluminous minerals. Thus, ampassed over red-hot oxide of copper, it is monia, by being a constituent of the atmoconverted, either completely or partially, sphere, is a very widely diffused cause of into binoxide of nitrogen. nitrification, which will come into play When ammoniacal gas -is conducted over whenever the different conditions necessary peroxide of manganese or iron heated to for the oxidation of ammonia are combined. redness, a large quantity of nitrate of ammo-'It is probable that other organic bodies in nia is obtained, if the ammonia be in excess; the state of eremacausis are the means of and the same decomposition happens when causing the combustion of ammonia; at all ammonia and oxygen are together passed events, the cases are very rare, in which over red-hot spongy platinum, nitric acid is generated -from ammonia, in It appears, therefore, that the combination the absence of all matter capable of eremaof oxygen with nitrogen occurs rarely during causis. the combustion of compounds of the latter From the preceding observations on the element with carbon, but that nitric acid is causes of fermentation, putrefaction, and dealways a product when ammonia is present cay, we may now draw several conclusions in the substance exposed to oxidation. calculated to correct the views generally enThe cause wherefore the nitrogen in am- tertained respecting the fermentation of wine monia exhibits such a strong disposition to and beer, and several other important probecome converted into nitric acid is un- cesses of decomposition which occur in doubtedly that the two products, which are nature. the result of the oxidation of the constituents of ammonia, possess the power of uniting with one another. Now this is not the case in the combustion of compounds of carbon CHAPTER IX. and nitrogen; here one of the products is carbonic acid, which, on account of its ON VINOUS FERMENT.TION:-WiNE AND gaseous form, must oppose the combination BEER. of the oxygen and nitrogen, by preventing their mutual contact, while the superior IT has already been mentioned, that feraffinity of its carbon for the oxygen during mentation is excited in the juice of grapes the act of its formation will aid this effect. by the access of air; alcohol and carbonic When sufficient access of air is admitted acid being formed by the decomposition of during the combustion of ammonia, water the sugar contained in the fluid. But it was is formed as well as nitric acid, and both of also stated, that the process once commenced, these bodies combine together. The pre- continues until all the sugar is'completely sence of water may, indeed, be considered as decomposed, quite independently of any one of the conditions essential to nitrification, further influence- of the air. since nitric acid cannot exist with6ut it. In addition to the alcohol and carbonic Eremacausis is a kind of putrefaction, dif- acid formed by the fermentation of the fering from the common process ofputrefac- juice, there is also produced a yellow or tlon, only m the part which the oxygen ofthe. gray insoluble substance, containing a large air plays in the transformations of the body in quantity of nitrogen. It is this body which decay. When this is remembered, and when possesses the power of inducing fermentait is considered that in the transposition of the tion in a new solution of sugar, and which elements of azotised bodies their nitrogen as- has in consequence received the name of sumes the form of ammonia, and that in this ferment. 104 AGRICULTURAL CHEMISTRY. The alcohol and carbonic- acid are pro- soluble state. These considerations, thereduced from the elements of the sugar, and fore, as well as the circumstance which all the ferment from those azotised constituents the experiments made on this subject appear of the grape-juice, which have been termed to point out, that the conversion of gluten gluten, or vegetable albumen. to the insoluble state is the result of oxidaAccording to the experiments of De tion, lead us to conclude that the oxygen Saussure, fresh impure gluten evolved, in consumed in this process is derived from the five weeks, twenty-eight times its volume of elements of water, or from the sugar which a gas which consisted J of carbonic acid, contains oxygen and hydrogen in the same and ~ of pure hydrogen gas; ammoniacal proportion as water. At all events, the oxvsalts of several organic acids were formed gen thus consumed in the fermentation of at the same time. Water must, therefore, wine and beer -is not taken from the atmobe decomposed during the putrefaction of sphere. gluten; the oxygen of this water must enter The fAlnentation of pure sugar in coninto combination with some of its consti- tact with yeast must evidently be a very diftuents, whilst hydrogen is liberated, a cir- ferent process from the fermentation of cumstance which happens only in decom- wort or must.5 positions of the most energetic kind. Nei- In the former case, the yeast disappears ther ferment nor any substance similar to it during the decomposition of sugar; but in is formed in this case; and we have seen the latter, a transformation of' gluten is that in the fermentation of saccharine vege- effected at the same time, by which'ferment table juices, no escape of hydrogen gas takes is generated. Thus yeast is destroyed in the place. one case, but is formed in the other. It is evident that the decomposition which Now since no free hydrogen gas can be gluten suffers in an isolated state, and' that detected during the fermentation of beer and which it undergoes when dissolved in a ve- wine, it is evident that the oxidation of the'getable juice, belong to two different kinds gluten, that is, its conversion into ferment, of transformations. There is reasonto be- must take place at the cost either of the oxylieve that its chanyge to the insoluble state gen of the water, or of that of the sugar; depends upon an absorption of oxygen, for whilst the hydrogen which is set free must its separation in this state may be effected, enter into new combinations, or by the deunder certain conditions, by free exposure oxidation of the sugar. new compounds conto the air, without the presence of ferment-, taining a large proportion of hydrogen, and mg sugar. It is known also that the juice small quantity of oxygen, together with the' of grapes, or vegetable juices in general, carbon of the sugar, must be formed. become turbid when in contact with air, be- It is well lnown that wine and fermented fore fermentation commences; and this tur- liquors generally contain, in addition to the bidity is owing to the formation of an inso- alcohol, other substances which could niot luble precipitate of the same nature as fer- be detected before their fermentation, and ment. which must have been formed, therefore, From the' phenomena which have been during that process in a manner similar to observed during the fermentation of wort," it the production of mannite. The smell and is known with perfect certainty that ferment taste which distinguished wine from all is formed from gluten at the same time that other fermented liquids are known to depend the transformation of the sugar is effected; upon an ether of a volatile and highly comfor the wort contains the azotised matter of bustible acid; the ether is of an oily nature, the corn, namely, gluten in the same condi- and has received the name mEnanthic ether. tion as it exists in the jtiice of grapes. The It is also ascertained that the smell and taste wort ferments by the addition of yeast, but of brandy from corn and potato are owing after its decomposition is completed, the to a peculiar oil, the oil of potatoes. This quantity of ferment or yeast is found to be oil is more closely allied to alcohol in its thirty times greater than it was originally. properties, than to any other organic subYeast from beer and that from wine, ex- stance. amined under the microscope, present the These bodies are products of the deoxidasame form and general appearance. They tion of the substances dissolved in the ferare both acted on in the same manner by menting liquids; they contain less oxygen alkalies and acids, and possess the power of than sugar or gluten, but are remarkable for inducing fermentation anew in a solution of the large quantity of hydrogen which enters sugar; in short, they must be considered into their composition. as identical.' (Enanthic acid contains an equal number The fact that water is decomposed during of equivalents of carbon and hydrogen, the putrefaction of gluten has been con- exactly the same proportions of these elepletely proved. The tendency of the carbon ments, therefore, as sugar, but by no means of the gluten to appropriate the oxygen of the same proportion of oxygen. The oil of water must also always be in action, whether potatoes contains much more hydrogen. the gluten is decomposed in a soluble or in- Although it cannot be doubted that these * Wort is an infusion of malt; it consists of the * The liquid expressed from grapes when fully soluble parts of this substance dissolved in water. ripe is called must. VINOUS FERMENTATION. 105 volatile liquids are formed by a mutual in- Experience has shown that the simultaterchange of the elements of gluten and,neous fermentation or putrefaction of the sugar, in consequence, therefore, of a true cellular tissue, by which this oil is generated, -process of putrefaction,.still it is certain, that may be completely pikevented in the fabricaother causes exercise an influence upon their tion of brandy friom corn. production and peculiarities..The same malt, which in the preparation The substances in wine to which its taste of brandy yields a fluid containing the oil of and smell are owing, are generated during which we are speaking, affords in the forthe fermentation of the juice of such grapes mation of beer a spirituous liquor, in which as contain a certain quantity of tartaric acid; no trace of that oil can be detected. The they, are not found in wines which are free principal difference in the preparation of the from all acid, or which contain a different two liquids is, that in the fermentation of organic acid, such as acetic acid. wort, an aromatic substance (hops) is added, The wines of warm climates posless no and it is certain that its presence modifies odour; wines grown in France have it in a the transformations which take place. Now marked degree, but in the wines from the it is known that the volatile oil of mustard, Rhine the perfume is most intense. The and the empyreumatic oils, arrest completely kinds of grapes on the Rhine, which ripen the action of yeast; and although the oil of very late, and scarcely ever completely, such hops does not possess this property, still it as the Riessling and Orleans, have the diminishes, in a great degree, the influence strongest perfume or bouquet, and contain, of decomposing azotised bodies upon the proportionally, a larger quantity of tartaric conversion of alcohol into acetic acid. There acid. The earlier grapes, such as the /u- is, therefore, reason to believe that some lander, and others, contain a large propor- aromatic substances, when added to fermenttion of alcohol, and are similar to Spanish ing mixtures, are capable of producing very, wines in their flavour, but they possess no various modifications in the, nature of the bouquet. products generated. The grapes grown at the -Cape, from Whatever opinion, however, may be held Riesslings transplanted from the Rhine, regarding the origin of the volatile odorifeproduce an excellent wine, which does not, rous substances obtained in the fermentation however, possess the aroma which distin- of wine, it is quite certain that the characguishes Rhenish wine. teristic smell of' wine is owing to an ether It is evident from these facts, that the acid of an organic acid, resembling one of the of wines, and their characteristic perfumes, fatty acids (cenanthic ether.) have some connexion, for they are always It is only in liquids which contain other found together; and it can scarcely be very soluble acids, that the-fatty acids and doubted that the presence of -the former cenanthic acids are capable of entering into exercises a certain influence on the forma- combination with the ether of alcohol, and tion of the latter. This influence is very of thus producing compounds of a peculiar plainly observed in the fermentation of li- smell. This ether is found in all wines quids, which are quite free from'tartaric which contain free acid, and is absent from acid, and particularly of those which are those in which no acids are present. This nearly neutral or alkaline, such as the mansh acid, therefore, is the means by which the of potatoes or corn. smell is produced; since without its presence r'he brandy obtained from corn and pota- cenanthic ether could not be formed. toes contains an ethereal oil of a similar com- The greatest, part of the oil of brandy position in both, to which these liquors owe made from corn consists of a fatty acid not their peculiar smell. This oil is generated converted into ether; it dissolves oxide of during the fermentation of the mash; it exists copper and metallic oxides in general, and ready formed in the fermented'liquids, and combines with the alkalies. distils over with alcohol, when a gentle heat The principal constituent of this oil is an is applied. acid identical in composition with tenanthic It is observed that a greater quantity of{ acid, but different in properties. (Mulder.) alcohol is obtained when the mash is made It is formed in fermenting liquids, which, if quite neutral by means of ashes or carbonate they be acid, contain only acetic acid, a body of lime, but that the proportion of oil in the which has no influence in causing other brandy is also increased. acids to form ethers. Now it is known that brandy made from The oil of brandy made from potatoes is potato starch, which has been converted the hydrate of an organic base analogous to into sugar by dilute sulphuric acid, is com- ether, and capable, therefore, of entering into pletely free from the potato oil, so that combination with acids. It is formed in this substance must. be generated in con- considerable quantity in fermenting liquids sequence of a change suffered by the cel- which- are slightly alkaline; under circumlular tissue of the potatoes during their fermentation. ernao I * In the manufactory of M. Dubrunfaut, so con. siderable a quantity of this oil is obtained under ~ 1ash is the mixture of malt, potatoes, and- certain circumstances from brandy made from water, in the mash tun, a large vessel inwhich it potatoes, that it might be employed for the pur. ie infused. pose of illuminating his whole manufactory.. 14 106 AGRICULTURAL CHTEMISTRY. stances, consequently, in which it is inca- and smell, which the addition of the water pable of combining with an acid. distilled from a quantity a hundred times The products of the fermentation and greater would not effect. The various kinds putrefaction of neutral vegetable and animal of beer manufactured in Bavaria are dismatters are generally accompanied by sub- tinguished by different flavours, which are stances of an offensive odour; but'the most given by allowing small quantities' of the remarkable example of the generation of a herbs and blossoms of particular plants to true ethereal oil is'seen in the fermentation ferment along with the wort. On the Rhine, of the Herba centlauriurz minorius, a plant also, an artificial bouquet is often given to which possesses no smell. When it is ex- wine for fraudulent purposes, by the addition posed in water to a slightly elevated tempe- of several species of the sage and rue to the rature it ferments, and emits an- agreeable fermenting liquor; but the fictitious perfume penetrating odour. By the distillation of the thus obtained differs from the genuine aroma, liquid, an ethereal oily substance of great by its inferior durability, and by being gravolatility is obtained, which excites a prick- dually dissipated. ing sensation in the eyes, and a flow of The juice of grapes grown in different tears. (Biichner.) climates differs not only in the proportion The leaves of the tobacco plant present of free acid which it contains, but also in the same phenomena; when fresh they pos- respect of the quantity of sugar dissolved in sess very little or no smell. When they are it. The quantity of azotised matter in the subjected to distillation with water, a weak juice seems to be the same in whatever part ammoniacal liquid is obtained, upon which the grapes may grow; at least no difference a fatty crystallizable substance swims, which has been observed in the amount of yeast does not contain nitrogen, and is quite desti- formed during fermentation in the south of tute of smell. But when the same plant, France, and on the Rhine. after being dried, is moistened with water, The grapes grown in hot climates, as well tied together in small bundles, and placed as the boiled juice obtained from them, are in heaps, a peculiar process of decomposi- proportionally rich in sugar. Hence, during tion takes place. Fermentation commences, the fermentation of the juice, the complete and is accompanied by the absorption of decomposition of its azotised matters, and oxygen; the leaves now become warm and their separation in the insoluble state, are esiiit the characteristic smell of prepared, to- effected before all the sugar has been conbacco and snuff. When the fermentation is verted into. alcohol and carbonic acid..A carefully promoted and too high a heat certain quantity of the sugar consequently avoided, this smell increases and becomes remains mixed-with the wine in an undemore delicate; and after the fermentation is composed state, the condition necessary for completed, an oily azotised volatile matter its further decomposition being absent. called nicotine is found in the leaves. This The azotised matters in the juice of grapes substance-nicotine, which possesses all the of the temperate zones, on the contrary, are properties of a base, was not present before not completely separated in the insoluble the fermentation. The different kinds of state, when the entire transformation of the tobacco are distinguished from one another, sugar is effected. The wine of these grapes, like wines, by having very different odorife- therefore, does not contain sugar, but varirous substances, which are generated along able quantities of undecomposed gluten in with the nicotine. solution. We know that most of the blossoms and This gluten gives the wine the property vegetable substances which possess a smell of becoming spontaneously converted into owe this property to a volatile oil existing vinegar, when the access of air is not prein them; but it is not less certain, that others vented. For it absorbs oxygen and becomes emit a smell only when they undergo change insoluble; and its oxidation is commnunior decomposition. cated to the alcohol, which is converted into Arsenic and arsenious acid are both quite acetic acid.' inodorous. It is only during their oxidation By allowing the wine to remain at rest in that they emit their characteristic odour of casks with a very limited access of air, and garlic. The oil of the berries of the elder- at the lowest possible temperature, the oxidatree, many kinds of oil of turpentine, and oil tion of this azotised matter is effected withof lemons, possess a smell only during their out the alcohol undergoing the same change, oxidation or decay. The same is the case a higher temperature being necessary to with many blossoms; and Geiger has shown, enable alcohol to combine with oxygen. As that the smell of musk is owing to its gradual long as the wine in the stilling-casks deputrefaction and decay. posits yeast, it can still be caused to ferment It is also probable, that the peculiar odor- by the addition of sugar, but old well-layed ous principle of many vegetable substances wine has lost this property, because the conis newly formed during the fermentation of dition necessary for fermentation, namely, a the saccharine juices of the plants. At all substance in the act of decomposition or events, it is a fact, that very small quantities putrefaction, is no longer present in it. of the blossoms of the violet, elder, linden, In hotels and other places where wine is or cowslip, added to a fermenting liquid, are drawn gradually from a cask, and a proporsufficient to communicate a very strong taste tional quantity of air necessarily introduced, VINOUS FERMENTATION. 107 its eremacausis, that is, its conversion into ation of gluten or other azotised matters is acetic acid, is prevented by the addition of a a process consisting of several stages. The small quantity of sulphurous acid, This first stage is the conversion- of the gluten acid, by entering into combination with the into insoluble ferment-in the interior of the oxygen of the air contained in the cask, or liquid, and as the transformation of the sudissolved in the wine, prevents the oxidation gar goes on at the same time, carbonic acid of the organic'matter. and yeast are simultaneously disengaged. The various kinds of beer differ from one It is known with certainty, that this formaanother in the same way as the wines. tion of yeast depends upon oxygen being English, French, and most of the German appropriated bythe gluten in the,act of debeers, are converted into vinegar when ex- composition; but it has not been sufficiently posed to the action of air. But this property shown whether this oxygen is derived from is not possessed by Bavarian- beer, which the water, sugar, or from the gluten itself; may be kept in vessels only half filled with- whether it combines directly with the gluout acidifying or experiencing any change. ten, or merely with its hydrogen, so as to This valuable quality is.obtained for-it by a form water. For the purpose of obtaining peculiar management of the fermentation of a definite idea of the process, we may dethe wort. The perfection of experimental signate the first change as the stage of oxidaknowledge has here led to the solution of tion. This oxidation of the gluten then, one of the most beautiful problems of the and the transposition of the atoms of the theory of fermentation. - sugar into alcohol and carbonic acid, are Wort is proportionally richer in gluten necessarily attendant on each other, so that -than in sugar, so that during its fermenta- if the one is arrested the other must also tion in the common way, a great quantity cease. of yeast is formed as a thick scum. The Now, the yeast which rises to the surface carbonic acid evolved during the process at- of the liquid is not the product of a comtaches itself to the particles of the yeast, by plete -decomposition, but is oxidised gluten which they become specifically lighter than still capable of undergoing a new transformthe liquid in which they are formed, and rise ation by the transposition of its constituent to its surface. Gluten in the act of oxida- elements. By virtue of this condition it has tlon comes' in contact with the particles of the power to excite fermentation in a solutlle decomposing sugar in the interior of the tion of sugar; and if the gluten be also preliquid. The carbonic acid from'the sugar sent, the, decomposing sugar induces its and insoluble ferment from the gluten -are conversion into fresh yeast, so that, in a cerdisengaged simultaneously, and cohere to- tain sense, the yeast appears to reproduce gether. itself. A great quantity of gluten remains dis- Yeast of this kind is oxidised gluten in a solved in the fermented liquid, even after the state of put'refaction, and by virtue of this transformation of the sugar is completed, state it induces a similar transformation in and this gluten causes the conversion of the the elements of the -sugar. alcohol into acetic acid;, on account of its The yeast formed during the fermentation strong disposition to attract oxygen, and to of Bavarian beer is oxidis-ed gluten in a state undergo decay. Now, it is plain, that'with of decay. The process of decomposition its separation, and that of all substances ca- which its constituents are suffering, gives pable of attracting oxygen, the beer would rise to a very protracted putrefaction (feirlose the property of-becoming acid. This menrtction) in the sugar. The intensity of end is completely attained in the process of the action is diminished in so great a degree, fermentation adopted in Bavaria. that the gluten which the fluid still holds in The wort, after having been treated with solution takes no part in it; the sugar in hops in the usual manner, is thrown into fermentation does not excite a similar state very wide flat vessels, in which a large sur- in the gluten. face of the liquid is exposed to the air. But the contact of the already decaying The fermentation is then allowed to proceed, and precipitated gluten or yeast causes the while the temperature of the' chambers in eremacausis of the gluten dissolved in the which the vessels are placed is never allowed wort; oxygen gas is absorbed from the air, to rise above 45 to 50~ F. The fermentation and all the gluten in solution is deposited as lasts from three to six weeks, and the car- yeast. bonic acid evolved during its continuance is The ordinary frothy yeast may be removed not in large bubbles which burst upon the from fermenting beer by filtration, without surface of the liquid, but in small bubbles the fermentation being thereby arrested; but like those which escape from a liquid satu- precipitated yeast of Bavarian beer cannot rated by high pressure. The surface of the be removed without the whole process of its wort is scarcely covered with a scum, and fermentation'being interrupted. The beer all the yeast is deposited on the bottom of ceases to ferment altogether, or, if the temthe vessel in the form of a viscous sediment. perature is raised, undergoes the ordinary In order to obtain a clear conception of fermentation. the great difference between the two kinds The precipitated yeast does not excite orof fermentation, it may perhaps be sufficient dinary fermentation, and consequently is to recall to mind the fact, that the transform- quite unfitted for the purpose. of baking; -but 108 AGRICULTURAL CHEMISTRY. the common frothy yeast can cause the kind hol from combining with oxygen. The reof fermentation by which the former kind moval of these substances- diminishes the of yeast is produced. tendency of the beer to become acescent, or When common yeast is added to wort at in other words, to suffer a farther transforma. a temperature of between 400 and 450 F., a tion. slowtranquil fermentation takes place, and In Appert's mode of preserving food, a matter is deposited on the bottom of the oxygen is allowed to enter into combination vessel, which may be employed to excite with' the substance of the food, at a tempenew fermentation; and when the same ope- rature at which decay, but neither putrefacration is repeated several times in succession, tion nor fermentation, can take place. With the ordinary fermentation changes into that the subsequent exclusion of the oxygen and process by which only precipitated yeast is the completion of the decay, every cause formed. The yeast now deposited has lost which could effect farther decomposition of the property-of exciting ordinary fermenta- the food is removed. The conditions fbr tion, but it produces the other process even putrefaction are rendered insufficient in both at a temperature of 500 F. cases; in the one by the removal of the In wort subjected to fermentation, at a substances susceptible of decay, in the other low temperature, with this kind of yeast, by the exclusion of the oxygen which would the. condition necessary for the transforma- effect it. tion of the sugar is the presence of that It has been stated to be uncertain, whether yeast; but for the conversion of gluten into gluten during its conversion into common ferment by a process of oxidation, some- yeast, that is, into the insoluble state in thing more is required. which it separates from fermenting liquids, When the power of gluten to attract oxy- really combines directly with oxygen. If it gen is increased by contact with precipitated does combine with oxygen, then the difference yeast in a state of decay, the unrestrained between gluten and ferment w-ould be, that access of air is the only other condition the latter would contain a larger proportion necessary for its own conversion into the of oxygen. Now it is very difficult to assame state of decay, that is for its oxidation. certain this, and even their analyses cannot We have already seen that the presence of decide the question., Let us consider, for free oxygen and gluten are conditions which example, the relations of alloxan and alloxdetermine the eremacausis of alcohol and antin~ to one another.. Both of these bodies its conversion into acetic acid, but they are contain the same elements as gluten, although incapable of exerting this influence at low in different proportions. Now they are known temperatures. A low temperature retards to be convertible into each other, by oxygen the slow combustion of alcohol, while the being- absorbed in the one case, and in the gluten combines spontaneously with- the other extracted. Both are composed of aboxygen of the air, just as sulphuric acid solutely the same elements, in equal prodoes when dissolved in water. Alcohol un- portions; with the single exception, that aldergoes no such change at low temperatures, lqxantin contains 1 equivalent of hydrogen but during the oxidation of the gluten in more than alIoxan. contact with it,- is placed in the same condi- When alloxantin is treated with chlorine tion as the gluten itself when sulphurous and nitric acid, it is converted into alloxan, acid is added to the wine in which it is con- into a body, therefore, which is alloxantin tained. The oxygen of the air unites both minus 1 equivalent of hydrogen. If on the with the gluten and alcohol of wine not other hand a stream of sulphuretted' hydrotreated with sulphurous' acid; but when this gen is conducted through alloxan, sulphur acid is present it combines with neither of is precipitated, and alloxantin produced. It them, being altogether absorbed by the acid. may be said, that in the first case hydrogen The same thing happens in the peculiar pro- is abstracted, in the other added. But it cess of fermentation adopted in Bavaria. The would be quite as simple an explanation, if oxygen of the air unites only with the gluten we considered them as oxides of the same and not with the alcohol, although it would radical: the alloxan being regarded as a have combined with- both at higher: tempe- combination of a body composed of Cs Nz ratures, so as to form acetic acid.- H2 08 with 2 equivalents of water, and alThus, then, this remarkable process of loxantin as a combination of 3 atoms of fermentation with the precipitation of a mu- water, Wlthl a compound consisting of C8 cous-like ferment consists of a simultaneous Nt HY OG. The conversion of alloxan into putrefaction and decay in the same liquid. alloxantin would in this case result from its The sugar is in the state of putrefaction, eight atoms of oxygen being reduced to and the gluten in that of decay. seven, while alloxan would be formed out Appert's method of preserving food, and of, alloxantin, by its combining with an adthis kind of fermentation of beer,'depend on ditional atom of oxygen. the same principle.' Now, oxides are known which combine In the fermentation of beer after this man- with water, and present the same phenoner, all the substances capable of decay are mena as alloxan and alloxantin. But no separated from it by means of an unrestrained access of air, while the temperature * Compounds obtained by the action of nitria is kept sufficiently low to prevent the alco- acid on uric acid. FERMENTATION OF BEER 109 compounds of hydrogen are known which ferment, and not in the formation of alcohol. form hydrates; and custom, which rejects But in the fermentation of Bavarian beer all all dissimilarity until the claim to peculiarity the sugar is expended in the production of is quite proved, leads us to prefer an opinion, alcohol; and this is especially the case when- for which there is no farther foundation than ever the transformation of the sugar is not that of analogy. The woad (Isatis tinctoria) accompanied by the formation of yeast. and several species of the JVeriunm contain a It is quite certain that in the distilleries of substance similar in many respects to gluten, brandy from potatoes, where no yeast is which is deposited as indigo blue, when an formed, or only a quantity corresponding to aqueous infusion of the dried leaves is ex- the malt which has been added, the proporposed to the action of the air. Now it is tion of alcohol and carbonic acid obtained very doubtful whether the blue insoluble in- during the fermentation of the mash corredigo is an oxide of the colourless soluble sponds exactly to that of the carbon contained indigo, or the latter a combination of hydro- in the starch. It is also known that the gen with the indigo blue. Dumas has found volume of carbonic acid evolved during the the same elements in both, except that the fermentation of beet-roots gives no exact insoluble compound contained 1 equivalent of dication of the proportion of sugar contained hydrogen more than the blue. in them, for less carbonic acid is obtained In the same manner the soluble gluten than the same quantity of pure sugar would may be considered a compound of hydrogen, yield. which becomes ferment by losing a certain Beer obtained by the mode of fermentaquantity of this element when exposed to tion adopted in Bavaria contains more alcothe action of the oxygen of the air under fa- hol, and possesses more intoxicating propervourable circumstances. At all events, it is ties, than that made by the ordinary method certain that oxygen is the cause of the in- of fermentation, when the quantities of soluble condition of gluten; for yeast is not malt used are thyi same. The strong taste deposited on keeping wine, or during the of the former beer is generally ascribed to its fermentation of Bavarian beer, unless oxy- containing carbonic acid in larger quantity, gen has access to the fluid. and in a state of more intimate combination; Now whatever be the form in which the but this opinion is erroneous. Both kinds oxygen unites with the gluten-whether it of beer are, at the conclusion of the fermencombines directly with it or extracts a por- tation, completely saturated with carbonic tion of its hydrogen, forming water-the acid, the one as much as the other. Like,products formed in the interior of the liquid,, all other liquids, they both must retain such in consequence of the conversion of the glu- a portion of the carbonic acid evolved as ten into ferment, will still be the same. Let corresponds to their power of solution, that us suppose that gluten is a compound of an- is, to their volumes. other substance with hydrogen, then this The temperature of the fluid during ferhydrogen must be removed during the ordi- mentation has a very important influence nary fermentation of must and wort, by on the quantity of alcohol generated. It combining with oxygen, exactly as in the has been mentioned, that the juice of beetconversion of alcohol into aldehyd by ere- roots allowed to ferment at from 860 to 950 macausis. (300 to 350 C.) yields no alcohol; and that In both cases the atmosphere is excluded; afterwards, in the place of the sugar, manthe oxygen cannot, then, be derived from nite, a substance incapable of fermentation, the air, neither can it be supplied by the and containing very little oxygen, is found, elements of water, for it is impossible to sup- together with lactic acid and mucilage. The ose that the oxygen will separate from the formation of these products diminishes in hydrogen of water, for the purpose of unit- proportion as the temperature is lower. But ing with the hydrogen of gluten, in order in vegetable juices, containing nitrogen, it is again to form water. The oxygen must, impossible to fix a limit, where the transtherefore, be obtained from the elements of formation of the sugar is undisturbed by sugar, a portion of which substance must, any other process of decomposition. in order tq the formation of ferment, undergo It is known that in the fermentation of a different decomposition from that which Bavarian beer the action of the oxygen of produces alcohol. Hence a certain part of the air, and the low temperature, cause the sugar will not be converted into carbonic complete transformation of the sugar into acid and alcohol, but will yield other pro- alcohol; the cause which would prevent that ducts containing less oxygen than sugar it- result, namely, the extraction of the oxygen self contains. These products, as has already of part of the sugar by the gluten, in its been mentioned, are the cause of the great conversion into ferment, being avoided by diffeIence in the qualities of fermented li- the introduction'of oxygen from without. quids, and particularly in the quantity of The quantity of matters in the act of alcohol'which they contain. transformation is naturally greatest at the Must and wort do not, therefore, in ordi- beginning of the fermentation of must and nary fermentation, yield alcohol in propor-' wort; and all the phenomena which accomtion to the quantity of sugar which they pany the process, such as evolution of gas, hold in solution, a part of the sugar being and heat, are best observed at that time. employed in the conversion of gluten into These signs of the changes proceeding in K 110 AGRICULTURAL CHEMISTRY. the fluid diminish when the greater part of are different, so that it is necessary to conthe sugar has undergone decomposition; sider each separately. but they must cease entirely before the pro- The first takes place when it is in the cess can be regarded as completed, moist condition, and subject to free uninterThe less rapid process of decomposition rupted access of air; the second occurs which succeeds the violent evolution of gas, when the air is excluded; and the third continues in wine and beer until the sugar when the wood is covered with water, and has completely disappeared; and hence it is in contact with putrefying organic matter. observed, that the specific gravity of the It is known that woody fibre may be kept liquid diminishes during many months. under water, or in dry air, for thousands of This slow fermentation, in most cases, re- years without suffering any appreciable sembles the fermentation of Bavarian beer, change; but that when brought into contact the transformation of the dissolved sugar with air, in the moist condition, it converts the being in part the result of a slow and con- oxygen surrounding it into the same volume tinued decomposition of the precipitated of carbonic acid, and is itself gradually yeast; but a complete separation of the changed into a yellowish brown, or black azotised substances dissolved in it cannot matter, of a loose texture.* take place'when air is excluded.* It has already been mentioned, that pure Neither alcohol alone, nor hops, nor in- woody fibre contains carbon and the eledeed both together, preserve beer from be- ments of water. Humus, however, is not coming acid. The better kinds of ale and produced by the decay of pure woody fibre, porter in England are protected from acidity, but by that of wood which contains foreign but at the loss of the interest of an immense soluble and insoluble organic substances, capital. They are placed in large closed besides its essential constituents. wooden vessels, the surfaces of which are The relative proportion of the component covered with sand. In these they are al- elements are, on this account, different in lowed to lie for several years, so that they oak wood and in beech, and the composition are treated in a manner exactly similar to of both of these differs very much from wine during its ripening. woody fibre, which is the same in all vegeA gentle diffusion of air takes place tables. The difference, however, is so tri. through the pores of the wood, but the quan- vial, that it may b~e altogether neglected in tity of azotised substances being very great the consideration of the questions which' in proportion to the oxygen which enters, will now be brought under discussion; bethey consume it, and prevent its union with sides, the quantity of the foreign,'s'ubstances the alcohol. But the beer treated in this is not'constant, but varies according to th'e way does not keep for two months without season of the year. acidifying, if it be placed in smaller vessels, According to the careful analysis of Gayto which free access of the air is permitted. Lussac and Thenard, 100 parts of oak wood, dried at 2120 (1000 C.,) from which all soluble substances had been extracted by means of water and alcohol, contained CHAPTI3[ ER N. 52-53 parts of carbon, and 47-47 parts of hydrogen and oxygen, in the same proporDECAY OF WOODY FIBRE. tion as they are contained in water. Now it has been mentioned- that.moist THE conversion of woody fibre into the wood acts in oxygen gas exactly as if its substances termed humus and mould is, on carbon combined directly with oxygen, and account of its influence on vegetation, one that the products of this action are carbonic of the most remarkable processes of decom- acid and hum'us. position which occur in nature. If the action of the oxygen were confined Decay is not less important in another to the carbon of the wood, and if nothing point of view; for, by means of its influ- but carbon were removed from it, the reence on dead vegetable matter, the oxygen maining elements would necessarily be which plants retained during life is again found in the humus, unchanged' except in restored to the atmosphere. the particular of being combined with less The decomposition of woody fibre is ef- carbon. The final result of the action would fected in' three forms, the results of which therefore be a complete disappearance of the carbon, whilst nothing but the elements of * The great influence which a rational manage- water would remain. ment of fermentation' exercises upon the quality But when decaying wood is subjected to of beer is well known in several of the German examination in different stages of its decay, states. In the grand-duchy of Hesse, for example, a considerable premium is offered- for the preparation of beer, according to the Bavarian method; * According to the experiments of De Saussure, and the premium is to be adjudged to any one 240 parts of dry sawdust of oak wood convert 10 who can prove that the beer brewed by him has cubic inches of oxygen into the same quantity of lain for six months in the store-vats without be- carbonic acid, which contains 3 parts, by weight, coming acid. Hundreds of casks of beer became of carbon; while the weight of the sawdust is dichanged to vinegar before an empirical knowledge minished by 15 parts. Hence, 12 parts, by weight, of those conditions was obtained, the influence of of water, are at the same time separated from tho which is rendered intelligible by the theory. elements of the wood. DECAY OF WOODY FIBRE. 11l the remarkable result is obtained, that the is well known that corrosive sublimate is proportion of carbon in the different products employed for the purpose of protecting the augments. Consequently, if we did not timber of ships from decay; it is a substance take into consideration the evolution of car- which completely deprives vegetable or anibonic acid under the influence of the air, mal matters, the most prone to decomposithe conversion of wood into humus might tion, of their property of entering. into ferbe viewed as a removal of the elements of mentation, putrefaction, or decay. water from the carbon. But the decay of woody fibre is very The analysis of mouldered oak wood, much accelerated by contact with alkalies or which was taken from the interior of the alkaline earths; for these enable substances trunk of an oak, and possessed a chocolate to absorb oxygen, which do not possess'brown colour and the structure of wood, this power themselves; alcohol, gallic acid, showed that 100 parts of it contained 53'36 tannin, the vegetable colouring matters, and parts of carbon and 46-44 parts of hydrogen several other substances, are thus affected and oxygen in the same relative proportions by them. Acids produce quite an opposite as in water. From an examination of effect; they greatly retard decay. mouldered wood of a light brown colour, Heavy soils, consisting of loam, retain easily reducible to a fine powder, and taken longest the most important condition for the frorn another oak, it appeared that it con- decay of the vegetable matter contained in tained 56'211 carbon and 43-789 water. them, viz., water; but their impermeable These indisputable facts point out the nature prevents contact with the air. similarity of the decay of wood with the In moist sandy soils, particularly such as slow combustion or oxidation of bodies are composed of a mixture of sand and carwhich contain a large quantity of hydrogen. bonate of lime, decay proceeds very quickly, Viewed as a kind of combustion, it would it being aided by the presence of the slightly indeed be a very extraordinary process, if alkaline lime. the carbon combined directly with the oxy- Now let us consider the decay of woody gen; for it would be a combustion in which fibre during a very long period of time, and the carbon of the burning body augmented suppose that its cause is the gradual removal constantly, instead of diminishing. Hence of the hydrogen in the form of water, and it is evident that it is the hydrogen which is the separation of its oxygen in that of caroxidised at the expense of the oxygen of the bonic acid. It is evident that if we'subair; while the carbonic acid is formed from tract from the formula CS6, H22, 022, the 22 the elements' of the wood. Carbon never equivalents of oxygen, with 11 equivalents combines at common temperatures with of' carbon, and 22 equivalents of hydrogen, oxygen, so as to form carbonic acid. which are supposed to be oxidised by the In whatever stage of decay wood may be, oxygen of the air, and separated in the form its elements must always be capable of be- of water;'then from 1 atom of oak wood, ing represented by their equivalent numbers. 25 atoms of pure carbon will remain as the The following formula illustrates this fact final product of the decay. In other words, with great clearness: 100 parts of oak, which contain 52 5 parts C36' H22 022 —oak wood, according to Gay- of carbon, will leave as a residue 37 parts'Lussac and Thenard.'of carbon, which must remain unchanged, C35 H20 020-humus from oak wood (Meyer.)t since carbon does not combine with ox'ygn C34 H18 018-humus from oak wood (Dr. at common temperatures. Will.)t - But this final result is never'attained in It is evident from these numbers that for the decay of wood under common circumevery two equivalents of hydrogen which stances; and for this reason, that with the are oxidised, two atoms of oxygen and cue increase of the proportion of carbon in the of carbon are set free. residual humus, as in all decompositions of Under ordinary circumstances, woody this kind, its attraction for the hydrogen, fibre requires a very long time for its decay; which still remains in combination, also inbut this process is of course much accele- creases, until at length the affinity of oxygen rated by an elevated temperature and free un- for the hydrogen is equalled by that of the restrained access of air. The decay, on the carbon for the same element. contrary, is much retarded by absence of In proportion as the decay of woody fibre moisture, and by the wood being surrounded advances, its property of burning with flame, with an atmosphere of carbonic acid, which or in other words, of developing carburetted prevents the access of air to the decaying hydrogen on the application of heat, dimimatters. nishes. Decayed wood burns without flame; Sulphurous acid, and all antiseptic sub- whence no other conclusion can be drawn, stances, arrest the decay of woody fibre. It than that the hydrogen, which analysis shows to be present, is not contained in it in the same form as in wood. * The calculation gives 52-5 carbon, and 47'5 Decayed oak contains more carbon than water. -t The calculation gves' 54 carbon, and 46 fresh wood, but its hydrogen and oxygen water. are in the same proportion. t TkI. calculation gives 56 carbon, and 44 We would naturally expect that the flame water. given out by decayed wood should be more 112 AGRICULTURAL CHEMISTRY. ordllhant, in proportion to the increase of its therefrom with greater rapidity than decayed carbon, but we find, on the contrary, that it wood, and replaces it by an equal volume of burns like tinder, exactly as if no hydrogen carbonic acid. When this carbonic acid is were present. For -the purposes of fuel, removed and fresh air admitted, the same decayed or diseased wood is of little value, action is repeated. for it does not possess the property of burn- Cold water dissolves only 1 - th of its ing with flame, a property upon which the own weight of vegetable mould; and the advantages of common wood depend. The residue left on its evaporation consists of hydrogen of decayed wood must conse- common salt with traces of sulphate of pot. quently be supposed to be in the state of ash and lime, and a -minute quantity of orwater; for had it any other form, the charac- ganic matter, for it is blackened when heated ters we have described would not be pos- to redness. Boiling water extracts several sessed by the decayed wood. substances from vegetable mould, and ac-, If we suppose decay to proceed in a liquid, quires a yellow or yellowish brown colour, which contains both carbon and hydrogen, which is dissipated by absorption of oxygen then a compound containing still more car- from the air, a black flocculent deposit being bon must be formed, in a manner similar to formed. When the coloured solution is the production of the crystalline colourless evaporated, a residue is left which becomes naphthalin from a gaseous compound of black on being heated to redness, and aftercarbon and hydrogen. And if the compound wards yields carbonate of potash when thus formed were itself to undergo further treted with water. decay, the final result must be the separation A solution of caustic potash becomes of carbon in a crystalline form. black when placed in contact with vegetable Science can point to no process capable mould, and the addition of acetic acid to the of accounting for the origin and formation coloured solution causes no precipitate or of diamonds, except the process of decay. turbidity. But dilute sulphuric acid throws Diamonds cannot be produced by the action down a light flocculent precipitate of a of fire, for a high temperature, and the pre- brown or black colour, from which the acid sence of oxygen gas, would call into play can be removed with difficulty by means of their combustibility. But there is the greatest water. When this precipitate, after having reason to believe that they are formed in the been washed with water, is brought whilst humid way, that is, in a liquid, and the pro- still moist under a receiver filled with oxycess of decay is the only cause to which their gen, the gas is absorbed with great rapidity; formation can with probability be ascribed. and the same thing takes place when the Amber, fossil resin, and the acids in mel- precipitate is dried, in the air. In the perlite, are the products of vegetable matter fectly dry state it has entirely lost its soluwhich has suffered decomposition. They bility in water, and even alkalies dissolve are found in wood or brown coal, and have only traces of it. evidently proceeded from the decomposition It is evident, therefore, that boiling water of substances which were contained in quite extracts a matter from vegetable mould, a different form in the living plants. They which owes its solubility to the presence of are all distinguished by the proportionally the alkaline salts contained in the remains small quantity of hydrogen which they con- of plants. This substance is a product of tain. -The acid from mellite (mellitic acid) the incomplete decay of woody fibre. Its contains precisely the same proportions of composition is intermediate between woody carbon and oxygen as that from amber (suc- fibre and humus, into which it is converted, cinic acid;) they differ only in the propor- by being exposed in a moist condition to tion of their hydrogen. M. Bromeis* found the action of -'he air. that succinic acid might be artificially formed by the action of nitric acid on stearic acid, a true process of eremacausis; the experiment CHAPTER' XII. was made in this laboratory (Giessen.) ON THE MOULD2RING OF BODIES.-PAPER, BROWN COAL, AND MINERAL COAL..CHAPTER XI. THE decomposition of wood, woody fibre, and all vegetable bodies when subjected to VEGETABLE MOULD. the action of water, and excluded from the THE term vegetable mould, in its general air, is termed mouldering. signification, is applied to a mixture of dis- Wood, or brown coal and mineral coal integrated minerals, with the remains of are the remains of vegetables of a former animal and vegetable substances. It may world; their appearance and characters be considered as earth in which humus is show, that they are products of the procontained in a state of decomposition. Its cesses of decomposition termed decay and action upon the air has, been fully investi- efaction. We can easily ascertain by gated by Ingenhouss and De Saussure. analysis the manner in which their constiWhen moist vegetable mould is placed in tuents have been changed, if we suppose a vessel full of air, it extracts the oxygen the greater part of their bulk to have been formed from woody fibre. * Liebig's Annalen, Band xxxiv., Heft 3. But it is necessary, before we can obtain MOULDERING OF BODIES. 113 a distinct idea of the manner in which coal The process of mouldering is, therefore is formed, to consider a peculiar change one of putrefaction and decay, proceeding which woody- fibre -suffers by means of simultaneously, in which the oxygen of the moisture, when partially or entirely ex- air and the componentparts of water take eluded from the air. part. But the composition of mouldered It is known, that wheh pure woody fibre, wood must change according as the access as linen, for example, is placed in contact of oxygen is more or less prevented. White with water, considerable heat is evolved, mouldered beech-wood yielded on analysis and the substance is, converted into a soft 47'67 carbon, 5-67 hydrogen, and 46'68 friable mass which has lost all coherence. oxygen; this corresponds to the formula This substance was employed in the fabri- C33 H25 024. cation of paper before the use of chlorine, as The decomposition of wood- assumes, an agent for bleaching.' The rags eniployed therefore, two different forms, according as for this purpose were placed in heaps, and the access of the air is free or restrained. it was observed, that on their becoming In both cases carbonic acid is generated; warm a gas was disengaged, and their and in the latter case, a certain quantity of weight diminished from 18 to 25 per cent. water enters into chemical combination. When sawdust moistened with water is It is highly probable that in this putrefacplaced in a. closed vessel, carbonic acid gas tive process, as well as in all others, the is evolved in the same manner as when air oxygen of the water assists in the formation is admitted. A true putrefaction takes place, of the carbonic acid. the wood assumes a white" colour, loses its Wood coal (brown coal of Werner) must peculiar texture, and is converted into a rot- have been produced by a process of decomten friable matter. position similar to that of mouldering. But The white decayed wood found in the in- it is not easy to obtain wood coal suited for terior of trunks of dead trees which have analysis, for it is generally impregnated with been in contact with water, is produced in resinous or earthy substances, by which the the way just mentioned. composition of those parts which have been An dnalysis of wood of this kind, ob- formed from woody fibre is essentially tained from the interior of the trunk, of an changed. oak, yielded, after having been dried at 212~, The wood coal, which forms extensive layers in the Wetterau (a district in Hesse Carbon 47'11 - 48'14 Darmstadt,) is distinguished from that found Hydrogen 6 31. - 6-06 tinguished from that found Oxygen 4531. 43 in other places, by possessing the structure Ashes 1'27 b. - 1'37 of wood unchanged, and by containing iio bituminous matter. This coal was subjected 100'00 100'00 to analysis, a piece being selected upon which the annual circle could be counted. Now, on comparing the proportions ob- It was obtained from the vicinity of Lautained from these numbers with the compo- bach; 100 parts contained sition of oak wood, according to the analysis of Gay-Lussac and Thenard, it is imme- Carbon.. 57'28 diately perceived, that a certain'quantity of Hydrogen 603 carbon has been separated from the consti- Oxygen - 3610 Ashes - - - 0'59 tuents of wood, whilst the hydrogen is, on the contrary, increased. The,numbers ob- 100'00 tained by the analysis correspond very nearly to the formula C33 H27 024. The large amount of carbon, and small The elements of water have, therefore, quantity of oxygen, constitute the most obbecome united with the wood, whilst car- ViOus difference between this analysis and bonic acid is disengaged by.the absorption that of wood. It is evident that the wood of a certain quantity of oxygen. which has undergone the change into coal If the elements of 5 atoms of water and 3 must have parted with a certain portion of atoms of oxygen be added to the composie its oxygen. The proportions of these nunmtion of the woody fibre of the oak, and 3 bers are expressed by the formula C33 H21 atoms of carbonic acid deducted, the exact 016.* formula for white mouldered wood is ob- When these numbers are compared with tained. those obtained by the analysis of oak, it would appear that the brown coal was proWood C36 H22 022 duced from woody fibre by the separation T atoms of oxygen - H 5 5 of one equivalent of hydrogen, and the elements of three equivalents of carbonic acid. C36 H-27 030 -, atom wood C36 H22 022 Subtract from this 3 atoms carbonic acid -3 0 6 Minus 1 atom hydrogen and 3 atoms carbonic acid C33 H27 02433 27 024 Wood coal, C33 H21 016' The calculation from this formula gives in 100 * The calculation gives 57'5 carbon, and 5'98 parts 47'9 carbon, 6'1 hydrogen, and 46 oxygen. hydrogen. 15 -R2 114 AGRICULTURAL CHEMISTRY. All varieties of wood coal, from whatever been effected, namely, a disengagement of strata.they may be taken, contain more hy- carbonic acid from their substance, appears drogen than wood does, and less oxygen still to go on at great depths in all the lavers than is necessary to form water with. this of wood coal. At all events it is remarkable hydrogen; consequently they must all be that springs impregnated with carbonic acid produced by the same process of decompo- occur in many places, in the country besition. The excess of hydrogen is either tween Meissner, in the electorate of Hesse, hydrogen of the wood which has remained and the Eifel, which are known to possess in it unchanged, or it is derived from some large layers of wood coal. These springs exterior source. The analysis of wood coal of mineral water are produced on the spot from Ringkuhl, near Cassel, where it is at which they are found; the springs of seldom found in pieces with the structure of common water meeting with carbonic acid wood, gave, when dried at 2120, during their ascent, and becoming impregnated with it. Cadroen 6260 - 63 83 In the vicinity of the layers of wood coal Hydrogen 50 - 4480 Oxygen 26'52 - - 25'51 at Salshausen (Hesse Darmstadt) an excelAshes- 586 - - 586 lent acidulous spring of this kind existed a 10000, few years ago, and supplied all the inhabi100'00 100'00 tants of that district; but it was' considered The proportions derived from these num- advantageous to surround the sides ct' the bers correspond very closely to the formula spring with sandstone, and the consequence C32 H15 097 or they represent the constitu- was, that all the outlets to the carbonic acid ents of wood, from which the elements of were closed, for this gas generally gains accarbonic acid, water, and 2 equivalents hy- cess to the water from the sides of the drogen, have been separated. spring. From that time to the present this valuable mineral water has disappeared, and C36 H22 022 4-Wood. Subtract C 4 H - 0134 atoms carbonicacid in its place is found a spring of common 5 atoms of water water. 2 atomsof hydrogen. Springs of water impregnated with carbonic acid occur at Schwalheim, at a very C32 HI5 0 9=-Wood Coal from Ring- short distanice from the layers of wood coal kuhl, at Dorheim.' M. Wilhelmi observed some The formation of both these specimens of time since, that they are formed of common wood coal appears from these formula to spring water which ascends from below, have taken place under circumstances which and of carbonic acid whitch issues from the did not entirely exclude the action of the air, sides of the spring. This same fact has and consequent oxidation and removal of a been shown to be the case in the famed certain quantity of hydrogen. Now the Fachinger spring, by M. Schapper. Laubacher coal is covered with a layer of The carbonic acid gas from the sprmgs in basalt, and the coal of Ringkuhl was taken the Eifel is, according to Bischoff, seldom from the lowest seam of layers, which pos- mixed with nitrogen or oxygen, and is prosess a thickness of from 90 to 120 feet; so bably produced in a manner similar to that that both may be considered aswell protected just described. At any rate the air does from the air. not appear to take any part in the formation During the formation of brown coal, the of these acidulous'springs. The carbonic elements of carbonic acid have been sepa- acid has evidently not been formed either by rated from the wood either alone, or at the a combustion at high or low temperatures; same time with a certain quantity of water. for if it were- so, the gas resulting from the It is quite possible that the difference in the combustion would necessarily be mixed with process of decomposition may depend upon - of nitrogen, but it does not contain a trace the high temperature and pressure under of this element. The bubbles of gas which which the decomposition took place. At escape from these springs are absorbed by least, a piece of wood assu med the character caustic potash, with the exception of a resiand appearace of Laubacher coal, after be- duum too small to be appreciated., ing kept for several weeks in the boiler of a The wood coal of Dorheim and Salzhausteam engine, and had then precisely the sen must have been formed in the same way same composition. The change in this case as that of the neighbouring village of Lauwas effected in water, at a temperature of bach; and since the latter contains the exact from 3340 to' 3520 F. (1500-160~ C.,) and elements of woody fibre, minus a certain under a corresponding pressure. The ashes quantity of carbonic acid, its composition of the wood amounted to 0-51 per cent.; a indicates very plainly the manner in which little less, therefore, than those of the Lau- it has been produced. bacher coal; but this must be ascribed to, The coal of the upper bed is subjected to the peculiar -circumstances under which it an incessant decay by the action of the air,' was formed. The ashes of plants examined by means of which its' hydrogen is removed by Bertnier amounted always to much more in the same manner as in the decay of wood. than this. This is recognised by the way in which it The peculiar process by which the de- burns, and by the formation of carbonic acid composition of these ext'rz: vegetables has in the mines. POISONS, CONTAGIONS, MIASMS. 1lb The gases which are formed in mines of after it had been treated with causLic potash wood coal, and cause danger in their work- showed its constituents to be, ing, are not combustible or inflammable as Gas from an in mines of mineral coal; but they consist abandoned Gerbard's Gasfroma mine near passage near mine near generally of carbonic acid gas, and are very Wallesweiler. Luisenthal. Liekwege. seldom intermixed with combustible gases. Vol. Vol. Yol. Wood coal from the middle bed of the, Light carburetted strata at Ringkuhl gave on analysis 65'40- hydrogen'9136 83.08 79.10 64l01 carbon and 4'75 —4-76~ hydrogen; the Oleant gas 6 32 198 1611 proportion of carbon here is the same as in Nitrogen gas 2'32 14'94 479 specimens procured from greater depths, but 10000o 100o00o 100oooo that of' the hydrogen is much less. The evolution of these gases proves that Wood and mineral coal are al~ways ac- changes are constantly proceeding in the companied by iron pyrites (sulphuret of coal. iron) or zinc blende (sulphuret of zinc;) It is obvious from this, that a continual which minerals are still formed from salts removal of oxygen in the form of carbonic of sulphuric acid, with iron or zinc, durinr i fm of o acid is effected fiom layers of wood coal, in the putrefaction of all vegetable matter. It consequence of which the wood must apis possible that the oxygen of the sulphates proach gradually to the composition of in the layers of wood coal is the means by mineralcoal. Hydrogen, on the contrary, is which the removal of the hydrogen is disengaoged from the constituents of mineral effected, since wood coal contains less of coal in theform-of a compound of carbo-hythis element than wood. y drogen; a complete removal of all the hydroAccording to the analysis of Richardson gen would convert coal into anthracite. and Regnault, the composition of the cor- The formula C36 H22 022, which is bustible materials in splint coal from New- given for wood, has been chosen as the erncastle, and cannel coal from Lancashire, pirical expression of the analysis, for the is expressed by the forimula iC24 H-I13 O. purpose of bringing all the transformations When -this is compared with the composition which woody fibre is capable of undergoing of woody fibre, it appears that these coals under one common point of view. are formed from its elements, by the re- Now, although the correctness of this moval of a certain quantity of carburetted formula must be doubted, until we know hydrogen and carbonic acid in the form of with certainty the true constitution of woody combustible oils. The composition of both fibre, this cannot have the smallestinfluence of these coals is obtained by the subtraction on the account given of the changes to which of 3 atoms of carburetted hydrogen, 3 atoms woody fibre must necessarily be subjected in of water, and 9 atoms of carbonic acid from order to be converted into wood or mineral the formula ofor b verted into wood or mineral the formula of wood. coal. The theoretical expression refers to the'quantity, the empirical mereiy to the.3 atoms of carbuoret-' relative proportion in which the elements of 3 atoms of carburetted hydrogen C3 H6 a body are united. Whatever form the first 3 atoms of water H3 03 m'ay assume, the empirical expression must.9atoms of carbonic always remain unchanged. acid - - C9 018 C12 H 9'021 Mineral coal[C24 H13 0 Carburetted hydrogen generally accom- CHAPTER XIII. panies all mineral coal; other varieties of coal contain volatile oils which may be sepa- ONPOISON NTAGIONS AND MIASMS. rated by distillation with water. (Reichenbach.) The origin of -naphtha is owing to A GREAT many chemical compounds, a, similar process of decomposition. Caking some derived from inorganic nature, and coal from Caresfield, near Newcastle, con- others formed in animals and plants, protains the elements of cannel coal, minus the duce peculiar changes or diseases in the constituents of olefiant gas C4 H4. living animal organism. They destroy the.The inflammable gases vwhich stream out vital functions of individual organs; and of clefts in the strata of mineral coal, or in when their action attains a certain degree rocks of' the coal formations, always con- ofintensity, death is the consequence. tain carbonic acid, according to' a recent The action of inorganic compounds, such examination by Bischoff, and also carburet- as acids, alkalies, metallic oxides, and salts, ted hydrogen, nitrogen, and oleflant gas; can in most -cases be easily explained. They the last of which had not been observed, either destroy the continuity of particular until its existence in these gases was pointed organs, or they enter into combination with out by Bischoff. The analysis offire-da;np their substance. The action of sulphuric, muriatic, and oxalic acids, hydrate of potash; and all those substances which produce * The analysis of brown coal from Ringkuhl, the direct destruction of the organs with as well as all those of the same substance given in this work, have been executed in this labora- which they come into contact, may be comtory by M. Kiihnert of Cassel...ared to a piece of iron, which can cause 116 AGRICULTURAL CI-IEMISTRY. death by mflicting an injury on particular During the passage of these salts through organs, either when heated to redness, or the lungs, their acids take part in the pecuwhen in the form of a sharp knife. Such -liar process of eremacausis which proceeds substances are not poisons in the limited in that organ; a certain quantity of the oxysense of the word, for their injurious action gen gas inspired unites with their constitudepends merely upon their condition. ents, and converts their hydrogen into water, The action of the proper inorganic poisons and their carbon into carbonic acid. Part is owing, in most cases, to the formation of of this latter product (I or 2 equivalents) a chemical compound by the union of the remains in combination with the alkaline poison with the constituents of the organ base, forming a salt which suffers no farther upon which it acts; it is owing to an exer- change by the process of oxidation; and it cise of a chemical affinity more.powerfil is this salt which is separated by the kidneys than the vitality of the organ. or liver. It is well'to consider the action of inor- It is manifest that the presence of these ganic substances in general, in order to ob- organic salts in the. blood must produce a tain a clear conception of the mode of action change in the process of respiration. A part of those which are poisonous. We find of the oxygen inspired, which usually comthat certain soluble compounds, when pre- bines with the constituents of the blood, sented to different parts of the body, are ab- must, when they are present, combine with sorbed by the blood, whence they are again their acids, and thus be prevented from pereliminated by the organs of secretion, either forming its usual office. The immediate in a changed or in an unchanged state. consequence of this must be the formation Iodide of potassium, sulpho-cyanuret of of'arterial blood in less quantity, or in other -potassium, ferro-cyanuret of potassium, words, the process of respiration must be chlorate of potash, silicate of potash, and all retarded. salts with alkaline bases, when administered Neutral acetates, tartrates, and citrates internally to man and animals in dilute solu- placed in contact with the air, and at the tions, or applied externally, may be again same time with animal or vegetable bodies detected in the blood, sweat, chyle, gall, and in a state of eremacausis, produce exactly splenic veins; but all of them are finally ex- the same effects as we have described them creted from the body through the urinary to produce in the lungs. They participate passages. in the process of decay, and are converted Each of these substances, in its transit, into carbonates just as, in the living body. produces a peculiar disturbance in the or- If impure solutions of these salts in water ganism-in other words, they exercise a are left- exposed to the air for any length of medicinal' action upon it, but they them- time, their acids. are gradually decomposed, selves suffer' no decomposition. If any of and at length entirely disappear. these substances enter into combination with Free mineral acids, or organic acids which any part of the body, the union cannot be are not volatile, and salts of mineral acids of a permanent kind; for-their reappearance with alkaline bases, completely arrest decay in the urine shows that' any compounds when added to decaying matter in sufficient thus formed must have been again decom- quantity; and when their quantity is small, posed by the vital processes. the process of decay is protracted and reNeutral citrates, acetates, and tartrates of tarded. They produce in living bodies the the alkalies, suffer change in their passage same phenomena as the neutral organic through the organism. Their bases can salts, but their action depends upon a differindeed be detected in the urine, but the acids ent cause. have entirely disappeared, and are replaced The absorption by the blood of a quantity by carbonic acid which has united with the of an inorganic salt sufficient to arrest the bases. (Gilbert Blane and W6hler.) process of eremacausis in the lungs, is preThe conversion of these salts of organic vented by a very remarkable property of all acids into carbonates, indicates that a con- animal membranes, skin, cellular tissue, siderable qantity of oxygen must have united muscular fibre, &c.; namely, by their incawith their elements. In order to convert 1 pability of being permeated by concentrated equivalent of acetate of potash into the car- saline solutions. It is only when these sobonate of the same base, 8 equivalents of lutions are diluted to a certain degree with oxygen must combine with it, of which water that they are absorbed by animal either 2 or 4 equivalents (according as an tissues. acid or neutral salt is produced) remain in A dry bladder remains more or less dry combination with the alkali; whilst the re- in saturated solutions of common salt, nitre, maining 6 or 4 equivalents are disengaged ferro-cyanuret of potassium, sulpho-cyanuas free carbonic acid. There is no evidence ret of potassium, sulphate of magnesia, presented by the organism itself, to which chloride of potassium, and sulphate of soda. these salts have been administered, that any These solutions run off its surface in the of its proper constituents have yielded so same manner as water runs from a plate of great a quantity of oxygen as is necessary glass besmeared with tallow. for their conversion into carbonates. Their Fresh flesh, over which salt has been oxidation can, therefore, only be ascribed strewed, is found after 24 hours' swimming to the oxygen of the air. in brine, although not a drop of water hat POISONS, CONTAGIONS, MIASMS. 117 been added. The water has been yielded When solutions of these salts are treated by muscular fibre itself, and having dis- with a sufficient quantity of albumen, milk, solved the salt in immediate contact with it, muscular fibre, and animal membranes, they and thereby lost the power of penetrating enter into combination with those subanimal substances, it has on this account stances, and lose their own solubility; while separated from the flesh. The water still the water in which they were dissolved loses retained by thile flesh contains a proportion- all the salt which it contained. ally small quantity of salt, having that de- The salts of alkaline bases extract water gree of dilution at which; a saline fluid is from animal substances; whilst the salts of capable of penetrating animal substances. the heavy metallic oxides- are, on the conThis property of animal tissues is taken trary, extracted from the water, for they advantage of in domestic economy for the enter into combination with the animal purpose of removing so much water from matters. meat that a sufficient quantity is not left to Now, when these substances are adminisenable it to enter into putrefaction.. tered to an animal, they lose their solubility In, respect of this physical property of by entering into combination with the memanimal tissues, alcohol resembles the inor- branes, cellular tissue, and muscular fibre; ganic salts. It is incapable of moistening, but in very few cases can they reach the that is, of penetrating, animal tissues, and blood. All experiments instituted for the possesses such an affinity for water as to purpose of determining whether they pass extract it from moist substances. into the urine have failed to detect them in When a solution of a salt, in a certain de- that secretion. In fact, during their pasgree of dilution, is introduced into the sto- sage through the organism, they come into mach, it is absorbed; but a concentrated contact with many substances by which saline solution, in place of being itself ab- they are retained. sorbed, extracts water from the organ, and The action of corrosive sublimate and a violent thirst ensues. Some interchange arsenious acid is very remarkable in this of water and salt takes place in the stomach; respect. It is known that these substances the coats of this viscus yield water to the possess, in an eminent degree, the property solution, a part of which having previously of'entering into combination with all parts become sufficiently diluted, is, on the other of animal and vegetable bodies, rendering hand, absorbed. But the greater part of the them at the same time insusceptible of decay concentrated solution of salt remains unab- or putrefaction. Wood and cerebral. subsorbed, and is not removed by the urinary stance are both bodies whicn undergo change passages; it consequently enters the intes- with great rapidity and facility when subtines and intestinal canal, where it causes a ject to the influence of air and water; but dilution of the solid substances deposited if they are digested for some time with arthere, and thus acts as a purgative. senious acid or corrosive sublimate, they Each of the salts just mentioned pos- may subsequently be exposed to all the irLsesses this purgative action, which depends fluences of the atmosphere without altering on a physical property shared by all of in colour or appearance. them; but besides this they exercise a me- It is farther known that those parts of a dicinal action, because every part of the body which come in contact with these suborganism with which they come in contact stances during poisoning, and which thereabsorbs a certain quantity of them. fore enter into combination with them, do The composition of the salts has nothing not afterwards putrefy; so that there can be to do with their purgative action; it is quite no doubt regarding the cause of their poia matter of indifference as far as the mere sonous qualities. production of this action is concerned (not It is obvious that if arsenious acid and as to its intensity,) whether the base be corrosive sublimate are not prevented by the potash or soda, or in many cases lime and vital principle from entering into combinamagnesia; and whether the acid be phos- tion with the component parts of the body, phoric, sulphuric, nitric, or hydrochloric. and consequently from rendering them incaBesides these salts, the action of which pable of decay and putrefaction, they must does not depend upon their power of enter- deprive the organs of the principal property ing into combination with the component which appertains to their vital condition, parts of the organism, there is a large class viz. that of suffering and effecting transof others which; when introduced into the formations; or, in other words, organic life living body, effect changes of a very differ- must be destroyed. If the poisoning is ent kind, and produce diseases or death, ac- merely superficial, and the quantity of the cording to the nature of these changes, with- poison so small that only individual parts out effecting a visible lesion of any organs. of the body which are capable of being reThese are the true inorganic poisons, the generated have entered into combination action of which depends upon their power with it, then eschars are produced-a pheof forming permanent compounds with the nomenon of a secondary kind-the comsubstance of the membranes, and muscular pounds of the dead tissues with the poison fibre. - being thrown off by the healthy parts. Salts of lead, iron, bismuth, copper, and From these considerations it may readily be mercury, belong to this class. inferred that all internal signs of poisoning 118 AGRICULTURAL CHEMISTRY. are variable and uncertain; for cases may nious acid or corrosive sublimate are requihappen, in which no apparent indication of site to produce deadly effects. change can be detected by simple observa- All substances, administered as antidotes tions of the parts, because, as has been al- in cases of poisoning, act by destroying the ready remarked, death may occur without power which arsenious acid and corrosive the destruction of any organs". sublimate possess, of entering into combiWhen arsenious acid is administered in nation with animal matters, and of' thus solution, it may enter into the blood. If a acting as poisons. Unfortunately no other vein is exposed and surrounded with a solu- body surpasses them in that power, and the tion of this acid, every blood-globule will compounds which they form can only be combine with it, that is, will become poi- broken up by affinities so energetic, that soned. their action is as injurious as that of the The compounds of arsenic, which have above-named poisons themselves. The duty not the property of entering into combina- of the physician consists, therefore, in his tion with the tissues of the organism, are causing those parts of the poison which without influence on life, even in large doses. may be free and still.uncombined, to enter Many insoluble basic salts of arsenious acid into combination with some- other body, so are known not to be poisonous. The sub- as to produce a compound incapable of stance called alkargen, discovered byBunsen, being decomposed or digested in the same has not the slightest injurious action upon conditions. Hydrated peroxide of iron is the organism; yet it contains a very large an invaluable substance for this purpose. quantity of arsenic, and approaches very WThen the action of arsenious acid or closely in composition -to the organic arse- corrosive sublimate is confined to the surnious compounds found in the body. face of an organ, those parts only are deThese considerations enable us to fix with stroyed which enter into combination with tolerable. certainty the limit at which the it; an eschar is formed, which is gradually above substances cease to act as poisons. thrown off. For since their combination with organic Soluble salts of silver would be quite as matters must be regulated by chemical laws, deadly. a poison as corrosive sublimate, did death will inevitably result, when the organ not a cause exist in the human body by in contact with the poison finds sufficient which their action is prevented, unless'their of it to unite with atom for atom; whilst if quantity is very great. This cause is the the poison is present in smaller quantity, a presence of common'salt in all animal part of the organ will retain its vital func- liquids. Nitrate of silver, it is well known, tions. combines with animal substances, in the According to the experiments of Mulder,' same manner as corrosive sublimate, and. the equivalent in which fibrin combines with the compounds formed by both are exactly muriatic acid, and with the oxides of lead similar in the character of being incapable and copper, is expressed by the number 6361. of decay or putrefaction. It may be assumed therefore approxima- When nitrate of silver.in a state of solutively, that a quantity of fibrin correspond- tion is applied to skin or muscular fibre, it ing to the number 6361 combines with 1 combines with them instantaneously; aniequivalent of arsenious acid, or 1 equiva- mal substances dissolved in any liquid are lent of corrosive sublimate. precipitated by it, and rendered insoluble, When 6361 parts of anhydrous fibrin are or, as it is usually termed, they are coagutombined with 30,000 parts of water, it is lated. The compounds thus'formed are in the state in which it is contained in mus- colourless, and so stable, that they cannot cular fibre or blood in the human body. be decomposed by other powerful chemical 100 g gins of fibrin in this condition would agents. They are blackened by exposure to form-a neutral compound of:equal equiva- light, like all other compounds of silver, in lents with 3-14 grains of arsenious acid, and consequence of a part of the oxide of silver 5 grains of corrosive sublimate. which they contain being reduced to the The, atomic weight of the albumen of metallic state. Parts of the body which eggs and of the blood deduced from the have united with salts of silver no longer analysis of the compound which it forms belong to the living organism, for their vital with oxide of silver is 7447, and that of functions have been arrested by combinaanimal gelatin 5652. tion with oxide of silver; and if they are 100 grains of albumen containing all the capable of being reproduced, the neighbour-water with which it is combined in the liv- ing living structures throw them off in the ing body, should consequently combine with form of an eschar. 1I grain of arsenious acid. When nitrate of silver is introduced into These proportions which may be consi- the stomach, it.meets with common salt and dered as the highest which can be adopted, free muriatic acid; and if its quantity is indicate the remarkably high atomic weights not too great, it is immediately converted.of animal substances, and at the same time into chlor.ide of silver-a substance which teach us what very small quantities of arse- is absolutely insoluble in pure water. In a ___________________ - solution of salt or muriatic acid, however, chloride of silver does dissolve in extremely. * Poggendorff's Annalen, Band xl. S. 259. minute quantity; and it is this small part POISONS, CONTAGIONS, MIASMS. 119 which exercises a medicinal influence when lowing law, long since proposed by La Place nitrate of silver is administered; the remain- and Berthollet, although its truth with reing chloride of silver is eliminated from the spect to chemical phenomena has only lately body in the ordinary way. Solubility is been proved. "'i molecule set in motion by necessary to give efficacy to any substance aI ny power can impart its own motion to in the human body. another molecule with which it may be in The soluble salts of lead possess many contact." properties in common with the salts of silver This is a law of dynamics, the operation and mercury; but all compounds of lead of which is manifest in all cases, in which with organic matters are capable of decom- the resistance (force, afility, or cohesion.)) position by dilute sulphuric acid. The dis- opposed to the motion is not sufficient to ease called painter's colic is unknown in all overcome it. manufactories of white lead in which the We have seen that ferment or yeast is a workmen are accustomed to take as a pre- body' in the state of decomposition, the servative sulphuric acid lemonade (a solu- atoms of which, consequently, are in a state tion of sugar rendered acid by sulphuric of motion or transposition. Yeast placed acid.) in contact with sugar communicates to the The organic substances which have cor- elements'of that compound the same state, bined in the living body with metallic oxides in consequence of which, the constituents or metallic salts, lose their property of im- of the sugar arrange themselves into new bibing water and retaining it, without at the and simpler forms, namely, into alcohol and same time being rendered incapable of per- carbonic acid. In these new compounds mitting liquids to penetrate through their the elements are united together by stronger pores. A strong contraction and shrinking affinities than they were in the sugar, and of the surface is the general effect of contact therefore under the conditions in which with these metallic bodies. But corrosive they were produced further decomposition sublimate, and several of the salts of lead, is arrested. possess a peculiar property, in addition to We know, also, that the elements, of those already mentioned. When they are sugar assumte totally different arrangements, present in excess, they dissolve the first when. the substances which excite their formed insoluble compounds, and thus pro- transposition are in a different state of deduce an effect quite the reverse of contrac- composition from the yeast just mentioned. tion, namely, a softening of the part of the Thus, when sugar is-acted on by rennet or body on which they have acted. putrefying vegetable juices, it is not conSalts of oxide of copper, even when in verted into alcohol and carbonic acid, but combination with the most powerful acids, into lactic acid, mannite, and gum. are reduced'by many vegetable substances, Again, it has been shown, that yeast particularly such as sugar and honey, either added to a solution of pure sugar gradually into metallic copper, or into the red sub- disappears, but that when added to vegeoxide, neither of which enters into combina- table juices which contain gluten as well as tion with animal matter. It is well known sugar, it is reproduced by the decomposition that sugar has been long employed as the of-the former substance. most convenient antidote for poisoning by The yeast with which these liquids are copper. made to ferment has itself been originally With respect to some other poisons, produced from gluten. namely, hydrocyanic acid and the organic The conversion of gluten into yeast in bases strychnia. and brucia, we are ac- these vegetable juices is dependent on the quainted with no facts calculated to eluci- decomposition (fermentation) of sugar; for, date the nature of their action. It niay, when the sugar has completely disappeared, however, be presumed with much certainty, any gluten which may still remain in the that experiments upon their mode of action liquid does not suffer change from contact. on different animal substances would very with the newly-deposited yeast, but retains quickly lead to the most satisfactory conclu- all the characters of gluten. sions regarding the cause of their poisonous Yeast is a product of the decomposition effects. of gluten; but it passes into a second stage There is a peculiar class of substances, of decomposition when in contact with which are generated during certain prto- water. On account of its being in this cesses of decomposition, and which act upon state of further change, yeast excites fermenthe animal economly as deadly poisons, not tation' in a fresh solution of sugar, and if on account of their power of entering into' this second saccharine fluid should contain combination with it, or by reason of their gluten, (should it be waot, for example,) containing a poisonous material, but solely yeast is again generated in consequence of by virtue of their peculiar condition. the transposition of the elements of tt:e In order to attain to a clear conception of sugar exciting a similar change in this the mode of action of these bodies, it is ne- gluten. cessary to call to mind the' cause on which After this explanation, the idea that yeast we have shown the phenomena of fermen- reproduces itself as seeds reproduce seeds, tation, decay, and putrefaction to depend. cannot for a moment be entertained. This cause may be expressed by the fol- From the foregoing facts it follows, that 120 AGRICULTURAL CHEMISTRY. a body in the act of decomposition (it may the spices and salt are deficient, and particube named the exciter,) added to a mixed larly when, they are smoked too late or not fluid in which its constituents are contained, sufficiently, they undergo a peculiar kind of can reproduce itself in that fluid, exactly in putrefaction, which begins at the centre of the same manner as new yeast is produced the sausage. Without any appreciable when yeast is added to liquids containing escape of gas taking place they become gluten. This must be more certainly, ef- paler in colour, and more soft and greasy iected. when the liquid acted upon contains in those parts which have undergone putrethe body by the metamorphosis of which the faction, and they are found to contain free exciter has been originally formed. lactic acid, or lactate of ammonia; products It is also obvious, that if the exciter be which are universally formed during the able to impart its own state of transformation putrefaction of animal and vegetable matto one only of the component parts of the ters. mixed liquid acted upon, its own reproduc- The cause of the poisonous nature of tion may be the consequence of the decom- these sausages was ascribed at first to hyposition of this one body. drocyanic acid, and afterwards to sebacic This law may be applied to organic sub- acid, although neither of these substances stances forming part of the animal organism. had been detected in them. But sebacic We know that all the constituents of'these acid is no more poisonous than benzoic acid, substances are formed from the blood, and with which it hias so many properties in that the blood by its nature and constitution common; and the symptoms produced are is one of the most complex of all existing sufficient to show that hydrocyanic acid is matters. not the poison. Nature has adapted the blood for the re- The' death which is the consequence of production of every individual part of the poisoning by putrefied' sausages succeeds organism; its principal character consists in very lingering and remarkable symptoms. its component parts being subordinate to There is a gradual wasting of muscular every attraction. These are in a perpetual fibre, and of all the constituents of the body state of change or transformation, which is similarly composed; the patient becomes effected in the most various ways'through much emaciated, dries to'a complete mumthe influence of the different organs. my, and finally dies. The carcase is stiff as The indivdual organs, such as the stomach, if frozen, and is not subject to putrefaction. cause all the; organic substances conveyed During the progress of the disease the saliva to them which are capable of transformation becomes viscous and acquires an offensive to assume new forms. The stomach com- smell. pels the elements of these substances to' Experiments have been made for the purunite into a compound fitted for the form- pose of ascertaining the presence of some ation of the blood. But the blood pos- matter in the sausages to which their poisesses no power of causing transformations; sonous action could be ascribed; but no such on the contrary, its principal character con- matter has been detected. Boiling water sists in its readily suffering transformations; and alcohol completely destroy the poisonand no other matter can be compared in this ous properties of the sausages, without respect with it. "themselves acquiring similar properties. Now it is a well-known fact, that when Now this is the peculiar character of all blood, cerebral substance, gall, pus, and substances which exert an action by virtue other substances in a state of putrefaction, of their existing condition-of those bodies are laid upon fresh wounds, vomiting, de- the elements of which are in the state of debility, and at length death, are occasioned. composition or transposition; a state which It is also well. known that bodies in anato- is destroyed by boiling -water and alcohol nical rooms frequently pass into a state of without the cause of the influence being imdecomposition which is capable of imparting parted to those liquids; for a state of action itself to the living body, the smallest cut or power cannot be preserved in a liquid. with a knife which has been used in their Sausages, in the state' here described, exdissection producing in these cases dan- ercise an action upon the organism, in congerous consequences. sequence of the stomach and other parts The poison of bad sausages belongs to this with which they come in contact not having class of noxious substances. Several hun- the power to arrest their decomposition; and dred cases are known in which death has entering the blood in some way or other, occurred from the use of this kind of food. while still possessing their whole power, In Wiirtemberg especially these cases'are they impart their peculiar action to the convery frequent, for there the sausages are pre- stituents of that fluid. pared from very various materials. Blood, The poisonous properties of decayed sauliver, bacon, brains, milk, meal, and bread, sages are not destroyed by the stomach as are mixed together with' salt and spices; those of the small-pox virus are. All the the mixture is then put into bladders or in- substances in the body capable of putrefactestines, and after being boiled is smoked. tion are gradually decomposed during' the When these sausages are well prepared, course of the disease, and after death nothing they may be preserved for months, and fur- remains except fat, tendons, bones, and a uish a nourishing savoury food; but when, few other substances which are incapable of POISONS, CONTAGIONS, MIASMS. 121 putrefying in the conditions afforded by the A peculiar matter, to which the poisonous body. action is due, cannot, we have seen, be exIt is impossible to mistake the modus ope- tracted from decayed sausages: and it is randi of this poison, for Colin has clearly equally impossible to obtain such a principle proved that muscle, urine, cheese, cerebral from the virus of small-pox or plague, and substance, and other matters, in a state of for this reason, that their peculiar power is putrefaction, conmmunicate their own state due to an active condition recognisable by of decomposition to substances much less our senses, only through. the phenomena prone to change of composition than the which it produces. blood. When placed in contact with a so- In order to explain the effects of contalution of sugar, they cause its putrefaction, gious matters, a peculiar principle of life has or the transposition of its elements into car- been ascribed to them-a life similar to that bonic acid and alcohol. possessed by the germ of a seed, which When putrefying muscle or pus is placed enables it under favourable conditions to deupon a fresh wound, it occasions disease velope and multiply itself. It would be imand death. It is obvious that these sub- possible to find a more correct figurative stances communicate their own state of pu- representation of these phenomena; it is one trefaction to the sound bloodfr.om which they which is applicable to contagions, as well were produced, exactly in the same manner as to ferment, to animal and vegetable subas gluten in a state of decay or putrefaction stances in a state of fermentation, putrefaccauses a similar, transformation in a solution tion or decay, and even to a piece of decayof sugar. ing wood, which by mere contact with fresh Poisons of this kind are even generated wood, causes the latter to undergo gradually by the body'itself in particular diseases. In the same change and become decayed and small-pox, plague, and syphilis, substances mouldered. of a peculiar nature are formed from the If the property possessed by a body of constituents of the blood. These matters producing such a change in any other subare capable of inducing in the blood of a stance as causes the reproduction,of itself, healthy individual a decomposition similar with all its properties, be regarded' as life, to that of which they themselves are the then, indeed, all the above phenomena may subjects; in other words, they produce the be ascribed to life. But in that case they same disease. The morbid virus appears to must not be considered as the only processes reproduce itself just as seeds appear to re- due to vitality, for the above interpretation produce seeds. of the expression embraces the majority of The mode of action of a morbid virus ex- the phenomena which occur in organic chehibits such a strong similarity to the action mistry. Life would, according to that view, of yeast upon liquids containing sugar and be admitted to exist in every body in which gluten, that the two processes have been chemical forces act. long since' compared to one another, al- If a body A, for example oamnide, (a subthough merely for the purpose of illustra- stance scarcely soluble in water, and without lion., But when the phenomena attending the slightest taste,) be brought into contact the action of each respectively are con- with another compound B, which is to be sidered more closely, it will in reality be reproduced; and if this second body be oxalic seen that their influence depends upon the acid dissolved' in water; then the following same cause. changes are observed to take place:-The In dry air, and in the absence of mois- oxamide is decomposed by the oxalic acid, ture, all these poisons remain for a long time provided the conditions necessary for their unchanged; but when exposed to the air in exercising an action upon one another are the moist condition, they lose very rapidly present. The elements of water unite with their peculiar properties. In the former the constituents of oxamide, and ammonia is case, those conditions are afforded which ar- one product formed, and oxalic acid the rtest their decomposition without destroying other, both in exactly the proper proportions it; in the latter, all the circumstances neces- to combine and form a neutral salt. sary for the completion of their decomposi- Here the contact of oxamide and oxalie tion are presented. acid induces a transformation of the oxaThe temperature at which water boils, mide, which is decomposed into oxalic acid and contact with alcohol, render such poi- and ammonia. The oxalic acid thus formed, sons- inert. Acids, salts of mercury, sul- as well as that originally added, are shared phurous acid, chlorine, iodine, bromine, by the ammonia —or in other words, as aromatic substances, volatile oils, and parti- much free oxalic acid exists after the decularly empyreumatic oils, smoke, and a composition as before it, and is of course decoction of coffee, completely destroy their still possessed of its original power. It matcontagious properties, in some cases com- ters not whether the free oxalic acid is that bining with them or otherwise effecting originally added, or that newly produced; their decomposition. Now all these agents, it is certain that it has been reproduced in an without exception, retard fermentation, pu- equal quantity by the decomposition. trefaction, and decay, and when present in If we now add to the same mixture a fresh sufficient quantity, completely arrest these portion of oxamide, exactly equal in quanprocesses of decomposition. tity to that first used, and treat it in the same 16 L 122 AGRICULTURAL CHEMISTRY. manner, the same decomposition is repeated; The vital principle is oaly knowll to us the free oxalic acid enters into combination, through the peculiar form cf its instruments, whilst another portion is liberated. In this that is, through the organs in which it remanner a very minute quantity of oxalic sides. Hence, whatever kind of energy a acid may be made to effect the decomposi- a substance may possess, if it is amorphous tion of several hundred pounds of oxamide; and destitute of organs front which the imand one grain of the acid to reproduce itself'pulse, motion or change proceeds, it does m.n unlimited quantity. not live. Its energy depend,: in this case on We know that the contact of the virus of a chemical action. Light, heat, electricity, small-pox causes such a change in the blood, or other influences may increase, diminish, as gives rise to the reproduction of the poi- or arrest this action, but they are not its efrison from the constituents of the fluid. This cient cause. transformation is not arrested until all the In the same way the vital principle goparticles of' the blood. which are susceptible verns the chemical powers in the living body. of the decomposition have undergone the All those substances to which we apply the metamorphosis. We have just seen that general name of food, and'all'the bodies the contact of oxalic acid with oxamide formed from them in the organism, are checaused the production of fresh oxalic acid, mical compounds. The vital principle'has, which in its turn exercised the same action therefore, no other resistance to overcome, on a new portion of oxamide. The trans- in order to convert these substances into formation was only arrested in consequence component parts of the organism, than the of the quantity of oxamide present being chemical powers by which their constituents limited. In their form both these transform- are held together. If the food possessed ations belong to the same class. But no life, not merely the chemical forces, butthis one except a person quite unaccustomed to vitality, would offer resistance to the vital view such changes will ascribe them to a force of the organism it nourished. vital power, although we admit they cor- All substances adapted for assimilation respond remarkably to our common concep- are bodies of a very complex constitution; tions of life; they are really chemical pro- their atoms are highly complex, and are cesses dependent upon the common chemical held together only by a weak chemical forces. action. They are formed by the union Our notion of life involves something of two or more simple compounds;' and in more than mere reproduction, namely, the proportion as the number of their atoms idea of an active power exercised by virtue augments their disposition to enter into new ofa definiteform, and production and gene- combinations is diminished; that is, they ration in a definite form. By chemical lose the power of' acting chemically upon agency we can produce the constituents of other bodies. muscular fibre, skin, and hair; but we can Their complex nature, however, renders form by their means no organized tissue, no them more liable to be changed, by the organic cell. agency of external causes, and thus to suffer The production of organs, the co-opera- decomposition. Any external agency, in tion of a system of organs, and their power many cases even mechanical friction, is not only to produce their component. parts sufficient to cause a disturbance in the equifrom the food presented to them, but to librium of the attraction of their constitugenerate themselves in their original form ents; they arrange themselves either into and with all their properties, are characters new, more simple, and permanent combinabelonging exclusively to organic life, and tions, or'if a foreign attraction exercise its constitute a form of reproduction indepen- influence upon' it, they arrange themselves dent of chemical powers. in accordance with that attraction. The chemical forces are subject to the The special characters of food, that is, of invisible cause by which this form is pro- substances fitted for assimilation, are absence duced. Of the existence of this cause itself of active chemical properties, and the capawe are made aware only by the phenomena bility of yielding to transformnations. which it produces. Its laws must be inves- The equilibrium in the chemical attractigated just as we investigate those of the tions of the constituents of the food is disother powers which affect motion and turbed by the vital principle, as we know it changes in matter. may be by many other causes. But the The chemical forces are subordinate to union of its elements, so as to produce new this cause of life, just as they are to elec- combinations and forms, indicates the pretricity, heat, mechanical motion, and'fric- sence of a peculiar mode of attraction, and tion. By the influence of the latter' forces, the existence of a power distinct from all, they suffer changes in their direction, an in- other powers of nature, namely, the vital crease or diminution of their intensity, or a principle. complete cessation or reversal of their action. All bodies of simple composition possess Such an influence and no other is' exer- a greater or less disposition to form combit ised by thevital principle overthe chemical nations. Thus oxalic acid is one of the forces; but in every case where combination simplest of the organic acids, while stearic or decomposition takes place, chemical affini- acid is one of the most complex; and the ty and cohesion are in action former is the strongest, the latter one of the POISONS, CONTAGIONS, MIASMS. 123 weakest, in respect to active chemical cha- Food will act as a poison, that is, it will racter. By virtue of this disposition, simple produce disease, when it is able to exercise compounds produce changes in every body a chemical action by virtue of its quantity; which offers no resistance to: their action; or, when either its condition or its presence they enter into combination and cause de- retards, prevents, or arrests the motion of composition. any organ. The vital principle opposes to the con- A compound acts as a poison when all the tinual action of the atmosphere, moisture parts of an organ-with which it is brought and temperature upon the organism, a re- into contact enter into chemical combination sistance which is, in a certain degree, invin- with it, while it may operate as a medicine, cible. It is by the constant neutralization when it produces only a partial chance. and renewal of these external influences No other component part of the organism that life and motion are maintained. can be compared to the blood, in respect of The greatest wonder in the living organ- the feeble resistance which it offers to exteism is the fact that an unfathomable wisdom rior influences. The blood is not an organ has made the cause of a continual decom- which is formed, but an organ in the act of' position or destruction, namely, the support formation * indeed, it is the sum of all the of the process of respiration, to be the means organs which are being formed. The cheof renewing the organism, and of resisting mihcal fobrce and the vital principle hold each all the other atmospheric influences, such other in such perfect equilibrium, that every as those of moisture and changes of tem- disturbance, however trifling, or from whatperature. ever cause it may proceed, effects a change When a chemical compound of simple in the blood. This liquid possesses so little constitution is introduced into the stomach, of permanence, that it cannot be removed or any other part of the organism, it must from the body without immediately sufferexercise a chemical action upon all sub- ing a change, and cannot come in contact stances with which it comes in contact; for we with any organ in the body, without yielding know the peculiar character of such a body to its attraction. to be an aptitude and power to enter into The slightest action of a chemical agent combinations and effect decompositions. upon the blood exercises an injurious influThe chemical action of such a compound ence; even the momentary contact with the is of course opposed by the vital principle. air in the lungs, although effected through The results produced depend upon the the medium of cells and membranes, alters strength of their respective actions: either the colour and other qualities of the blood. an equilibrium of both powers is attained, Every chemical, action propagates itself a change being effected without the destruc- through the mass of the blood; for, examtion of the vital principle, in which case a ple, the active chemical condition of the medicinal effect is occasioned; or the acting constituents of a body undergoing decombody yields to the superior force of vitality, position, fermentation, putrefaction, or dethat is, it is digested; or lastly, the chemical cay, disturbs the equilibrium between the action obtains the ascendency and acts as a chemical force and the vital principle in the poison. circulating fluid. Numerous modifications Every substance may be considered as in the composition and condition of the nutriment, which loses its former properties compounds produced from the elements of when acted on by the vital principle, and the blood, result from the conflict of the vital does not exercise a chemical action upon the force with the chemical affinity, in their inliving organ. cessant endeavour to overcome one another. Another class of bodies change the direc- All the characters of the phenomena of tion, the strength, and intensity of the re- contagion tend to disprove the existence of sisting force, (the vital principle,) and thus life in contagious matters. They without exert a modifying influence upon the func- doubt exercise an influence very similar to tions of its organs. They produce a dis- some processes in the living organism; but turbance in the system, either by their pre- the cause of this influence is chemical acsence, or by themselves undergoing a change; tion, which is capable of being subdued by these are medicaments. other chemical actions, by opposed agencies. A third class of compounds are called Several of the poisons generated in the poisons, when they possess the property of body by disease lose all their power when uniting with organs or with their component introduced into the stomach, but others are parts, and'when their power of effecting not thus destroyed. this is stronger than the resistance offered It is a fact very decisive of their chemical by the vital principle. nature and mode of action, that those poiThe quantity of a substance and its con- sons which are neutral or alkaline, such as dition must, obviously, completely change tShe poisonous matter of the contagious fever the mode of its chemical action, in. cattle (typhus' contaC(riosus rumlinantilin,) Increase of quantity is known to be equi- or that of the small-pox, lose their whole valent to superior affinity. Hence a medica- power of contagion in the stomach; whilst ment administered in excessive quantity may that of sausages, which has an acid reacact as a poison, and a poison in small doses tion, retains all its frightful properties under as a medicament. the sante circumstances. 124 AGRICULTURAL CHEMISTRY. In the former of these cases, the free acid sciences, are the foes of all inquiries into the present in the stomach destroys the action mysteries of nature; they are like the fata of the poison, the chemical properties of morgana, which show us deceitful views of which are opposed to it; whilst in the latter seas, fertile fields, and luscious fruits, but it strengthens, or at all events does not offer leave us languishing when we have nlost any impediment to poisondus action. need of what they promise. Microscopical examination has detected It is certain that the action of contagions peculiar bodies resembling the globules of is the result of a peculiar influence dependthe blood in -malignant putrefying pus, in ent on chemical forces, and in no wav conthe matter of vaccine, &c. The presence nected with the vital principle. This inof these bodies has given weight to the fluence is destroyed by chemical actions, opinion, that contagion proceeds from the and manifests itself wherever it is not subdevelopement of a diseased organic life; dued by some antagonist power. Its existand these formations have been regarded as ence is recognised in a connected series of the living seeds of disease. changes and transformations, in which it This view, which is not adapted to dis- causes. all substances capable of undergoing cussion, has led those philosophers who are -similar changes to participate. accustomed to search for explanations of An animal substance in the act of decomphenomena in forms, to consider the yeast position, or a substance generated from the produced by the fermentation of beer as pos- component parts of a living body by disease, sessed of life. They have imagined, it to commiunicates its own condition to all parts be composed of animals or plants, which of the system capable of entering into the nourish themselves from the sugar in which same state, if no cause exist in these parts they are placed, and at the same'time yield by which the change is counteracted or dealcohol and carbonic acid as excrementitious stroved. matters.? Disease is excited' by contagion. It would perhaps appear wonderful if The transformations produced by the disbodies, possessing a crystalline structure and ease assume a series of forms. geometrical figure, were formed during the In order to obtain a clear conception of processes of fermentation and putrefaction these transformations, we may consider the from the organic substances and tissues of changes which substances, more simply organs. We know, on the contrary, that composed than the living body, suffer from the complete dissolution into organic corn- the influence of similar causes. When pupounds is preceded by a series of trans- trefying blood or yeast in the act of transformations, in which the organic structures formation is placed in contact with a solugradually resign their forms. tion of sugar, the elements of the latter Blood, in a state of decomposition, may substance are transposed, so as to form alappear to the eye unchanged; and when we cohol and carbonic acid. recognise the globules of blood in a liquid A piece of the rennet-stomach of a calf contagious matter, the utmost that we can in a state of decomposition occasions the thence infer is, that those globules have elements of sugar to assume a different artaken no part in the process of decomposi- rangement. The sugar is converted into tion. All the phosphate of lime may' be lactic acid without the addition or loss of removed from bones, leaving them trans- any element. (1 atom of sugar of grapes parent and flexible like leather, without the C12 H12 012 yields two atoms of lactic form of the bones being in the smallest de- acid= —2 (C6 H6 06.) gree lost. Again, bones may be burned When the juice of onions or of beet-root until they be quite white, and consist merely is made to ferment at high temperatures, of a skeleton of phosphate of lime, but they lactic'acid, mannite, and gum are formed. will still possess their original form. In the Thus, according to the different states of the same way processes of decomposition in transposition of the elements of the exciting the blood may affect individual constitu- body, the elements of the sugar arrange ents only of that fluid, which will become themselves in different manners, that is, difdestroyed and disappear, whilst its other ferent products are formed. parts will maintain the original form. The immediate contact of the decomposSeveral kinds of contagion are propagated ing substance with the sugar is the cause through the air: so that, according to the by which its particles are made to assume view already mentioned, we must ascribe new forms and natures. The removal of life to a gas, that is, to an aeriform body. that substance occasions the cessation of the All the supposed proofs of the vitality of decomposition of the sugar, so that should contagions are merely ideas and figurative its transformation be completed before the representations, fitted to render the pheno- sugar, the latter can suffer no further mena more easy of apprehension by our change. senses, without explaining them. These In none of these processes of decomposifigurative expressions, with which we are tion is the exciting body reproduced; for so willingly and easily satisfied in all the conditions necessary to its reproduction do not exist in the elements of the sugar. * Annalen der Pharmacie, Band xxix. S. 93 Just as yeast, putrefying flesh, and the und 100. stomach of a calf in a state of decomposi POISONS, CONTAGIONS, MIASMS. 125 tion, when introduced into solutions of formation or decomposition proceeds more sugar, effect the transformation of this sub- slowly than that of the compound in the stance, without being themselves regene- blood, the decomposition of which it effects. rated; in the same manner, miasms, and If the transformation of the yeast genecertain contagious matters produce diseases rated in the fermentation of wort proceeded in the human organism, by communicating with the same rapidity as that of the partithe state of decomposition of which they cles of the sugar contained in it, both would themselves are the subject, to certain parts simultaneously disappear when the fermentof the organism, without themselves being ation was completed. But yeast requires a reproduced in their peculiar form and na- much longer time for decomposition thanture during the progress of the decompo- sugar, so that after the latter has completely sition. disappeared, there remains a much larger The disease in this case is not contagious. quantity of yeast than existed in the fluid at Now when yeast is introduced into a the commencement of the fermentation,mixed liquid containing'both sugar and glu- yeast which is still in a state of incessant ten, such as wort, the act of decomposition progressive transformation, and therefore of the sugar effects a change in the form and possessed of its peculiar property. nature of the gluten, which is, in conse- The state of change or decomposition quence, also subjected to transformation. which affects one particle of blood, is imAs long as some of the fermenting sugar re- parted to a second, a third, and at last -to all mains, gluten continues to be separated as the particles of blood in the whole body. yeast, and this new matter in its turn ex- It is communicated in like manner to the cites fermentation in a fresh soluti6n of blood of another individual, to that of a sugar or'wort. If the sugar, however, third person,-and so on-or in other words, should be- first decomposed, the gluten which the disease is excited in them also. remains in solution is not converted into It is quite certain that a number of pecuyeast. We see, therefore, that the repro- liar substances exist in the blood of some duction of the exciting body here depends- men and animals, which are absent from ]. Upon the presence of that substance the blood of others. from which it was originally formed; The blood of the same individual contains, 2. Upon the presence of a compound in childhood and youth, variable quantities which is capable of being decomposed by of substances, which are absent from it in contact with the exciting body. other stages of growth. The susceptibility If we express in the same terms the re- of contagion by peculiar exciting bodies in production of contagious matter in conta- childhood, indicates a propagation and regious diseases, since it is quite certain that generation of the exciting bodies, in conthey must have their origin in the blood, we sequence of the transformation of certain must admit that the blood of a healthy indi- substances which are present in the blood, vidual contains substances, by the decompo- and in the absence of which no contagion sition of which the exciting body or conta- could ensue. The form of a'disease is gion can be produced. It must further be termed benignant, when the tranformations admitted, when contagion results, that the are perfected on constituents of the body blood contains a second constituent capable which are not essential to life, without the of being? decomposed by the exciting body. other parts taking a share in the decomposiIt is only in consequence of the conversion tion; it is termed malignant when they of the second constituent, that the original affect essential organs. exciting body can be reproduced. It cannot be supposed that the different A susceptibility of contagion indicates the changes in the blood, by which its constitupresence of a certain quantity of this second ents are converted into fat, muscular fibre, body in the blood of a healthy individual. substance of the brain and nerves, bones, The susceptibility for the disease and its in- hair, &c., and the transformation of food into tensity must augment according to the quan- blood, can take place without the simultatity of that body present in the blood; and neous formation of new compounds which in proportion to its diminution or disappear- require to be removed from the body by the ance, the course of the disease will change. organs of excretion. When a quantity, however small, of con- In an adult these excretions do not vary tagious matter, that is of the exciting body, much either in their nature or quantity. is introduced into the blood of a healthy in- The food taken is not employed in increasing dividual, it will be again generated in the the size of the body, but merely for the purblood, just as yeast is reproduced from wort. pose of replacing any substances which may Its condition of transformation will be com- be consumed by the various actions in the municated to a constituent of the blood; and organism; every motion, every manifestain consequence of the transformation suf- tion of organic properties, and every organic fered hy this substance, a body identical with action being attended by a change in the or similar to the exciting or contagious mat- material of the body, and by the assumption ter will be produced from another consti- of a new form by its constituents.* tuent substance of the blood. The quantity of the exciting body newly produced must * The experiments of Barruel upon the dif. oonstantly augment, if its further trans- ferent odours emitted from blood on the addition L2 126 AGRICULTURAL CHEMISTRY. But in a child this normal condition of thrown into a state of decomposition is the sustenance is accompanied by an abnprmal newly-formed contagion. condition of growth and increase in the size The second substance must have been of the body, and of each individual part of originally a constituent of the blood: the it. Hence there must be a much larger first may be a body accidentally present; quantity of' foreign substances, not belong- but it may also be a matter necessary to life. ing to the organism, diffused through every If both be constituents indispensable for the part of' the blood in the body of a young support of the vital functions of certain individual. principal organs, death is the consequence When the organs of secretion are in pro- of their transformation. But if the absence per action, these substances will be re- of the one substance which was a constltumoved from the system; but when the func- ent of the blood do not cause an immediate tions of those organs are impeded, they will cessation of the functions of the most imremainin the blood or become accumulated portant organs, if they continue in their in particular parts of the body. The skin, action, although in an abnormal condition, lungs, and other organs, assume the func- convalescence ensues. In this case the protions of the diseased secreting organs, and ducts of the transformations still existing in the accumulated substances are eliminated the blood are used for assimilation, and at by them. If, when thus exhaled, these sub- this period secretions of a peculiar nature stances happen to be in the state of progres- are produced. sive transformation, they are contagious; When the constituent removed from the that is, they are able to produce the same blood is a product of an unnatural manner state of disease in another healthy organism, of living, or when its formation takes place provided the latter organism is susceptible only at a certain age, the susceptibility of of theiraction-or in other words, contains contagion ceases upon its disappearance. a matter' capable of suffering the same pro- The effects of vaccine matter indicate that cess of decomposition. an accidental constitution of the blood -is The production of matters of this kind, destroyed by a peculiar process of decomwhich render the body susceptible of conta- position, which does not affect the other gion, may be occasioned by the manner of constituents of the circulating fluid. living, or by the nutriment taken by an in- If the manner in which the precipitated dividual. A superabundance of strong and yeast of Bavarian beer acts (page 107) be otherwise wholesome food may produce called to mind, the modus operandi of vacthem, as well as a deficiency of nutriment, cine lymph can scarcely be matter of doubt. uncleanliness, or even the use of decayed Both the kind of yeast here referred to substances as food. and the ordinary ferment are formed from All these conditions for contagion must be gluten, just as the vaccine virus and the considered as accidental. Their formation matter of small pox are produced from the and accumulation in the body may be pre- blood. Ordinary yeast and the virus of vented, and they may even be removed from human small-pox, however, effect a violent it without disturbing its most important tumultuous transformation, the former in functions of health. Their presence is not vegetable juices, the latter in blood, in both necessary to life. of which fluids respectively their constituThe action, as well as the generation of ents are contained, and they are reproduced the matter of contagion is, according to this from these fluids with all their characview, a chemical process participated in by teristic properties. The precipitated yeast all substances in the living body, and by all of Bavarian beer on the other hand acts enthe constituents of those organs in which tirely upon the sugar of the, fermenting the vital principle does not overcome the liquid and occasions a very protracted dechemical action. The contagion, accord- composition of it, in which the gluten which ingly, either spreads itself over every part is also present takes no part. But the air of the'body, or is confined particularly to exercises an influence upon the latter subcertain organs, that is, the disease attacks stance, and causes it to assume a new form all the organs or only a few of them, ac- and nature, in consequence of which this cording to the feebleness or intensity of their kind of yeast also is reproduced. resistance. The action of the virus of cow-pox isIn the abstract chemical sense, reproduc- analogous to that of the low yeast; it comrn.. tion of a contagion depends upon the pre- municates its own state of decomposition to sence of two substances, one of which be- a matter in the blood,'and from a second comes completely decomposed, but commu- matter is itself regenerated, but by a totally nicates its own state of'transformation to different mode of decomposition; the prpthe second. The second substance thus duct possesses the mild form, and all the - properties of the lymph of cow-pox. of sulphuric acid, prove that peculiar substances The susceptibility of infection by the virus are contained in the blood of different individuals; of human small-pox must cease after vaccithe blood of a man of a fair complexion and that nation for the substance to the presence of of a man of dark complexion were found to yield hich different odours; the blood of animals also dif- hichthis susceptibility is owing has been fered in this respect very perceptibly from that of removed from the body by a' peculiar pro-, nma'. cess of decomposition artificially excited. POISONS, CONTAGIONS, MIASMS. 127 But this substance may be again generated But miasm, properly so called, causes in the same individual, so that he may again disease without being itself reproduced. become liable to contagion, and a second or All the observations hitherto made upon a third vaccination- will again remove the'gaseous contagious matters prove, that they peculiar substance from the system. also are substances in a state of decompoChemical actions are propagated in no sition. When vessels filled with ice are organs so easily as in the lungs, and it is placed in air impregnated with gaseous conwell known that diseases of the lungs are tagious matter, their outer surfaces become above all others frequent and dangerous. covered with water containing a certain If it is assumed that chemical action and quantity of this matter in solution. This the vital principle mutually balance each water soon becomes turbid, and in common other in the blood, it must farther be sup- language putrefies, or, to describe the chani-e posed that the chemical powers will have more correctly, the state of decomposition a certain degree of preponderance in the of the dissolved contagious matter is comnlungs, where the air and blood are in inlme- pleted in the water. diate contact; for these organs are fitted by All gases emitted from putrefyinganimal nature to favour chemical action; they offer and vegetable substances in processes of no resistance to the changes experienced by disease, generally possess a peculiar nauthe venous blood. seous offensive smell, a circumstance which, The contact of air with venous blood is in most cases, proves the presence of a body limited to a very short period of time by the in a state of decomposition. Smell itself motion of the heart, and any change be- may in many cases be considered as a reyond a determinate point is, in a certain action of the nerves of smell, or as a resistdegree, prevented by the rapid remnoval of ance offered by the vital powers to chemical the blood which has become arterialised. action. Any disturbance in the functions of the Many metals emit a peculiar odour when heart, and any chemical action from with- rubbed, but this is the case with none of out, even though weak, occasions a change the precious metals, —th'ose which. suffer no in the process of respiration. Solid sub- change when'exposed to air and moisture. stances also, such as dust from vegetable, Arsenic, phosphorus, musk, the oils of linanimal, or inorganic bodies, act in the same seed, lemons, turpentine, rue, and pepper-,way as they do in a saturated solution of a mint, possess an odour only when they are salt in the act of crystallization, that is, they, in the act of eremacausis (oxidation at comoccasion a deposition of solid matters from mon temperatures.) the blood, by which the action of the air The odour of gaseous contagious matters upon the latter is altered or prevented. is owing to the same cause; but it is also When gaseous and decomposing sub- generally accompanied by ammonia, which stances, or those which exercise a chemical may be considered in many cases as the action, such as sulphuretted hydrogen and means through which the contagious matter carbonic acid, obtain access to the lungs, receives a gaseous form, just as it is the they meet with less resistance in this organ means of causing the smell of innumerable than' in any other. The chemical process substances of little volatility, and of many of slow combustion in the lungs is accele- which have no odour. (P)obiquet.)~ rated by all substances in a state of decay Ammonia is very generally produced in or putrefaction, by ammonia and alkalies; cases of disease; it is always emitted in but it is retarded by empyreumatic sub- those in which contagion' is generated, and stances; volatile oils, and acids. Sulphu- is an invariable pIoduct of the decomposition retted hydrogen produces immediate decom- of animal matter. The presence-of ammoposition of the blood, and sulphurous acid nia in the air of chambers in which diseased combines with the substance of the tissues, patients lie, particularly of those afflicted the cells, and membranes.' with a contagious disease, may be readily When the process of respiration is modi- detected; for the moisture condensed by ice fled by contact with a matter in the pro- in the manner just described, produces a gress of decay, when this matter cornmu- white precipitate in a solution of corrosive nicates the state of decomposition, of which sublimate, just as a solution of ammonia it is the subject, to the blood, disease is pro- does. The ammoniacal salts also, which duced. are obtained by the evaporation of rainIf the matter undergoing decomposition water after an acid has been added, when is the product of a disease, it is called con- treated with lime so as to set free their amtagion; but if it is a product of the decay monia, emit an odour most closely resemor putrefaction of'animal and vegetable bling that of corpses, or the peculiar smell substances, or if it acts by its chemical pro- of dunghills. perties, (not by the state in which it is,) and By evaporating acids in air containing therefore enters into combination with parts gaseous contagions, the ammonia is neuof the body, or causes their decomposition, tralised, and we thus prevent further deit is termed miasm. composition, and destroy the power of the Gaseous contagious matter'is a miasm contagion, that is, its state of chemical emitted from blood, and capable of' generating itself again in blood * Ann. de Chim. et de Phys. XV, 27. I28 AGRICULTURAL CHEMISTRY. change. Muriatic and acetic acids, and in previously to their distillation with water, tne several cases nitric acid, are to be preferred residue does not vield a volatile oil. The for thlis purpose before all others. Chlorine alcohol contains a crystalline body called also is a substance which destroys ammonia sinapin, and Several other bodies. Those do and organic bodies with much facility; but not possess the characteristic pungency of it exerts such an injurious and prejudicial the oil, but it is by the contact of them with influence upon the lungs, that it may be water, and with the albuminous constituents classed amongst the most poisonous bodies of the seeds, that the volatile oil is formed. known, and should never be employed in Thus bodies regarded as absolutely indifplaces in which- men breathe. ferent in inorganic chemistry, on account of Carbonic acid and sulphuretted hydrogen, their possessing no prominent chemical which are frequently evolved from the earth characters, when placed in contact with one in cellars, mines, wells, sewers, and other another, mutually decompose each other. places, are amongst the most pernicious mi- Their constituents arrange themselves in a asms. The former may be removed from peculiar manner, so as to form new comthe air by alkalies, the latter, by burning binations; a complex atom dividing into two sulphur, (sulphurous acid,) or by the evapo- or more atoms of less complex constitution, ration of nitric acid. in consequence of a mere disturbance in the The characters of many organic corn- attraction of their elements. pounds are well worthy of the attention and The white constituents of the almonds study both of physiologists and pathologists, and mustard, which resemble coagulated almore especially in relation to the mode of bumen, must be in a peculiar state in order action of medicines and poisons. to exert their action upon amygdalin, and Several of such compounds are known, upon those constituents of mustard from which to all appearance are quite indifferent which the volatile pungent oil is produced. substances, and yet cannot be brought into If almonds, after being blanched and contact withi one another: in water without pounded, are thrown into boiling water, or suffering'a complete' transformation. All treated with hot alcohol, with mineral acids, substances which thus suffer a mutual de- or with salts of mercury, their power to composition, possess complex atoms; they effect a decomposition in amygdalin is combelong to the highest order of chemical com- pletely destroyed. Synaptas is an azotised pounds. For example, amygdalin, a con- body which cannot be preserved when disstituent of bitteralmonds, is a perfectly neu- solved in water. Its solution becomes tral body, of a slightly bitter taste, and very rapidly turbid, deposits a white precipitate, easily soluble in water. But when it is in- and acquires the offensive smell of putrefytroduced into a watery solution of synaptas, ing bodies. (a constituent of sweet almonds,) it disap- It is exceedingly probable that the pecupears completely without the disengagement liar state of transposition into which the eleof any gas, and the water is found to con- ments of synaptas are thrown when distain free hydrocyanic acid, hydruret of ben- solved in water, may be the cause of the zule (oil of bitter almonds,) a peculiar acid decomposition of amygdalin, and formation and sugar, all substances of which merely of the new products arising from it. The the elements existed in the amygdalin. The action of synaptas in this respect is -very same decomposition is effected when bitter similar to that of rennet upon sugar. almonds, which contain the same white Malt, and the germinating seeds of corn matter as the sweet, are rubbed into a pow- in general, contain a substance called diasder and moistened with water. Hence it tase, which is formed from the gluten conhappens that bitter almonds pounded and tained in them, and cannot be brought in digested in alcohol, yield no oil of bitter al- contact with starch and water, without effectmonds containing hydrocyanic acid, by dis- ing a change in the starch. tillation with water; for the substance which When bruised malt is strewed upon warm occasions the formation of those volatile sub- starch made into a paste with water, the stances, is dissolved by alcohol without paste after a few minutes becomes quite change, and is therefore extracted from the liquid, and the water is found to contain, in pounded almonds. Pounded bitter almonds place of starch, a substance in many respects contain no amygdalin, also, after having similar to gum. But when more malt is been moistened with water, for that sub- added and the heat longer continued, the stance is completely decomposedwhen they liquid acquires a sweet taste, and all the are thus treated. starch is found to be converted into sugar of No volatile compounds can be detected by grapes. their smell in the seeds of the Sinapis alba The elements of diastase have at the same and S. nig'ra. A fixed oil of a mild taste is time arranged themselves iinto new combinaobtained from them by pressure, but no trace tions. of a volatile substance. If, however, the The conversion of the starch contained in, seeds are rubbed to a fine powder, and sub-'food into sugar of grapes in diabetes indijected to distillation with water, a volatile cates that amongst the constituents of some oil of a very pungent taste and smell passes one organ of the body a substance or subover along with the steam. But if, on the stances exist in a state of chemical action, contrary, the seeds are treated with alcohol to which the vital principle of the diseased POISONS, CONTAGIONS, MIASMS. 129 organ opposes no resistance. The compo- ral attractions-the cause, therefore, by nent parts of the organ must suffer changes which they are made to assume their pecusimultaneously with the starch, so that the liar order and form in the body-is the vital more starch is furnished to it, the more ener- principle. getic and intense the disease must become; After the removal of the cause which while if only food which is incapable of forced their union-that is, after the extincsuffering such transformations from the tion of life-most organic atoms retain their same cause is supplied, and the vital energy condition, form, and nature, only by a vi.s inis strengthened by stimulant remedies and ertice; for a great law of nature proves that nourishment, the chemical action may finally matter does not possess the power of sponbe subdued, or, in other words, the disease taneous action. A body in motion loses its cured. motion only when a resistance is opposed to The conversion of starch into sugar may it; and a body at rest cannot be put in moalso be effected by pure gluten, and by dilute tion, or into any action whatever, without mineral acids. the operation of some exterior cause. From all the preceding facts, we see that The same numerous causes which are very various transpositions, and changes of opposed to the formation of complex organic composition and properties, may be pro- molecules, under ordinary circumstances, duced in complex organic molecules, by occasion their decomposition and transformevery cause which occasions a disturbance ations when the only antagonist power, the in the attraction of their elements. vital principle, no longer counteracts the inrWhen moist copper is exposed to air con- fluence of those causes. Contact with air taining carbonic acid, the contact of this and the most feeble chemical action now acid increases the affinity of the metal for effect changes in the complex molecules; the oxygen of the air in so great a degree even the presence of any body the particles that they combine, and the surface of the of which are undergoing motion or transpocopper becomes covered with green carbo- sition, is often sufficient to destroy their state nate of copper. Two bodies, which pos- of rest, and to disturb the statical equilibrium sess the power of combining together, as- in the attractions of their constituent elesume, however, opposite electric conditions ments. An immediate consequence of this at the moment at which they come in is that they arrange themselves according to contact. the different degrees of their mutual attrac-, When copper is placed in contact with tions, and that new compounds are formed iron, a peculiar electric condition.is excited, in which chemical affinity has the ascendin consequence of which the property of ency, and opposes any further change, the copper to unite with oxygen is destroyed, while the conditions under which these and the metal remains quite bright. compounds were formed remained unaltered. When formate of ammonia is exposed to a temperature of 3880 F. (1800 C.) the intensity and direction of the chemical force undergo a change, and the conditions under TABLES: which the elements of this compound are SHOING TE PROPORTION BETWEEN TH enabled to remain in the same form ceases HESSIAN AND ENTGLISH STANDARD OF to be present. The elements, therefore, ar- WEIGHTS AND NEASURES. range themselves, in a new form; hydrocyanic acid and water being the result of IN general all the weights and measures the change. employed in this edition are those of the Mechanical motion, friction, or agitation, English standard. In a few cases only, the is sufficient to cause a new disposition of Hessian weights and measures have been the constituents of fulminating silver and retained. In these the numbers do not remercury, that is, to effect another arrange- present absolute quantities, but are merely ment of their elements, in consequence of intended to denote a proportion to other which, new compounds are formed. numbers. This has been done to avoid any WVe know that electricity and heat possess unnecessary intricacy in the calculations, a decided influence upon the exercise of and to present whole numbers to the reader, chemical affinity; and that the attractions without distracting his attention by decimal of substances for one another are subordi- parts. For those, however, who wish to bh nate to numerous causes which change the acquainted with the exact English quanticondition of these substances, by altering ties, a table is given below. the direction of their attractions. In the 1 lb. English is equal to 0'90719 lbs. Hessame manner, therefore, the exercise of sian; hence, about one-tenth less than the chemical powers in the living organism is latter. dependent upon the vital principle. 1 lb. Hessian is equal to 1'102 lbs. English. The power of elements to unite together, 2 lbs. Hessian are equal to 2'204 " and to form peculiar compounds, which are 3 3- 3306 generated in animals and vegetables, is 4 4 409 chemical affinity; but the cause by which 6. 6 they are prevented from arranging them- 7 - -.. 7716 selves according to the degrees of their natu- 8 -. 8'818 " 17 130 AGRICULTURAL CHEMISTRY. 9 lbs. Hessian are equal to.992 lbs. English. figures, the whole series given in the case 10. 1102 of the pounds will also be obtained. 20 -...22'04. " 30.. 33'06 " 1 Sq. foot. Hessian is equal to 0'612 Sq. foot Eng. 40 - - - 44'09 " 2 feet - 1345 50 - - - 55'11 " 3. 2018 feet 60... 66'12 2 4 - 2691 70 - - - - 7716 5 - 3363 " 80... 8818 " 6 4... 036 " 90.. 99'29 7... 4709 100 -. - - 110-2 " 8 -..- - - 5382 " 200. - 220'4, 9 - 6'054. 300 - - 330'6 " 10. 6'727 " 400.. 440'9 " 500 -. - 5511 " ~ CUBIC FEET. 600. 661'2 " 600 -... 6612 One English cubic foot contains 181218 800 - -. - 881'8 " of a Hessian cubic foot; the Hessian and 900 -.. 992'0 " English cubic inch may be considered as 1000. - 1102'0 " equal, one English cubic inch containing 1048715 Hessian cubic inch. SQUARE FEET. 1 cub. foot Hessian is eq. to 0'551 cub. foot Eng. 2 feet - 1'103 The Hessian acre is equal to 40,000 Hes- 3 1665 feet sian square feet, or 26,911 English square 4 -.. 2-207 feet; 1 English square foot being equal to 5... 2'759 1'4864 Hessian. The following is a table 6 7 3311 to save the trouble of calculation. The 7 3863 " table is only stated to the figure 10, but by 9 4;4966 45 " removing the decimal point one or two 10-..... 5'518 " THE END, INDEX. A. wood, 110-Of night-soil, 60-Of salt water Absor~ption, by roots, 37-Of salts, 39 43-Of soils, 73-113-Of wood coal, 113 Acid, acetic, emitted by plants, 51-transforma- Animal food, preservation of, 101-Life, contion of, 92-formation of, 100, 10i2-Boracic, lexion of, with plants, 9-Bodies, products of 42-Carbonic, 10-contained in the atmo- decay, 30. sphere, 11-decomposed by plants, 16-from Animals, excrements of, 18, 63. Annual plants, how nourished, 46. respiration, 16-why necessary to plants, 36 -Cyanicj transformation of, 94-Formic, 25, Anthoxanthum odoratum, acid in, 33. 26, 88-Hippuric, 33-Humic,- 12-proper- 115. ties of, 13 —Hydrocyanic, 25, 88 —Kinic, 39- Antidotes to poisons, 118. Lactic, 64 —production of, 98-Meconic, 39-Apatite,53. Arable land, 50. nMelanic, 99-Nitric, soulrce of, 32-Phosphoic, Arable land, 50 in ashes of plants, o53-uceolic, in plantsp, 37 Aromatics, their influence on fermentation, 105. in ashes of plants, 53-Rocellic, in plants, 37 Argillaceous earth, its origin, 50. -Succinic, 112-Sulphuric, action of, on soils, Ar0 70, 84 -Tartaric, in grapes, 37. Arragonite, transformation of, 90. Acids, action of upon sugar, 92-Arrest decay, Ashes, as manure, 67-o mparative value of 118. 111 Capacity for saturation, 36-O0rganic, in Ashes, as manure, 67 —Comparative value of, 61 111-Capacity for saturation, 36-Organic, in Of fire-wood, 38-Of pine trees, 37-Of plants, lo, 36 —when formed, 13. — Of fire-wood, 38-Of pine trees, 37 -Of plafinity, 11,action 36-f, hen formedical, 18.examples of, plants, origin of salt in, 43-Importance of ex, Affinity, action of, 25-Chemical, examples of, 88-Weak, example of; 88. amination of, 38-Of wheat, 53-used as a SSWeak, example of, 88. manure, 72-Of bones, 62-Of peat, 62-Of Agave Americana, absorbs oxygen, 18. manure, -Of bones, 62- peat, 62-O Agriculture, in China, 65-Object of, 34, 49, 57 coas, — how attained, 49 —Its importance, 4-9-A — how attained, 49-Its importance, 49LA'Assimilation, of carbon, 12, 23-Of carbonic acid, principle in, 63. and ammonia, 45-Of hydrogen, 28, 29-Of Air, access of, favoured, 27-Ammonia in, 11, 32 nitrogen, 30, 36-Its power, 48. -Caronic acid in, 15 —Effect of upon juices, Atmosphere, ammonia in, 11, 32 —Composition of, 11-How maintained, 16-Composition is 100-on soils, 56-Improved by plants, 17-ecessaroy to plants, 44. invariable, 15 —Carbonic acid in the, 11 —MobumNecessary to plants, 44. tion of, 17. Albumcohol, 33ect of heat on, 93- ed, 25-Atoms, motions of 89-Permanence in position Alcohol, effect of heat on, 93-Exhaled, 25- of, 89. Products of its oxidation, 99-From sugar, 95..4ll~dehyde, 9y~9. ~Attraction, powerful, overcome, 94. Alkalies, from granitic soils, 40-Presence of, in- Azotised matter in juices of plants, 47-Sub dicated, 72-Promote decay in wood, 111- stances, combustion of, 102. Quantity in aluminous minerals, 50. Alkaline bases, in plants, on what their existence B. depends, 38-Salts in plants, sources of, 51- Bamboo, silica in, 58. contained in fertile soils, 52. - Bark of trees, products in, 18. Alloxan, 108. Barley, analysis of, 53. Alloxantin, 108. Barruel, his experiments on the blood, 125. Alumina, in fertile soils, 49-Its influence on Base, what, 36. vegetation, 49. Bases, alkaline, in plants, on what their existence Amber, origin of, 112. depends, 38-Organic, 11-Oxygen contained Ammonia, carbonate of, from wine, 64-how fixed, in, 36-Tn plants, 37-Substitution of, 37. 64 —Cause of nitrification, 103-Changes co- Beans, alkalies in, 54-Nutritive power of, 54. lours, 30 -Condensed by charcoal, 35-Con- Becquerrel, experiments of, 51. version of, into nitric acid, 103-Early exist- Beech, ashes of, 30. ence of, 42-Fixed by gypsum, 64-From Beer, 107 —109-Bavarian, 107-Varieties of. animals, 58-Contained in beet-root, &c., 32 106. -maple juice,. 33 —stables, &c., 64-Fur- Beet-root sugar, 14-Ammonia from, 32-From nishes nitrogen, 36-Loss from evaporation, sandy soils, 47. 34-Produced by animal organism, 42 —Pro- Benignant disease, 126. duct of decay, 30-disease, 129-Properties Benzoic acid, formed, 33. of, 31-Quantity absorbed by charcoal, 35- Birch tree, ammonia from, 33. by decayed wood, 35 —In rain-water, 31-Se- Blood, its office, 46-Action of chemical agents parated from soils by rain, 35 —In snow water, upon, 123-Its feeble resistance to exterior in. 32-Solubility of, 31-Transformation of, 30. fluences, 123-Organic salts in, 116-Its cha. Amylin, its effect, 26. racter, 120. Analysis of decayed wood, 111 —Of fire-damp, Blossoms, when produced, 24 —Increased, 45-. 115-Of guano, 67-Of lentils, 54-Of oak- Removal of, from potatoes, 46. 132 INDEX. Bones, dust of, 62-Durability of, 68-Gelatine Their effects explained, 121 —Life in, disproved in, 68-Use in compost, 72. 121-Reproduction of, 121. Bouquet of wines, 105. Copper alloy, its action, on sulphuric acid, 88. Boracic acid, 41. Corn, how cultivated in Italy, 52-Phosphate of Botanists, neglect of chemistry by, 20. magnesia in, 53. Brandy, from corn, 105-Oil of, 105. Corn brandy, 105. Brazil, wheat in, 52. Corrosive sublimate, action of, 118. Brown coal, 113. Cow, excrements of the, 41, 59, 60-Variable in Buckwheat, ashes of, 54. value, 60-Urine of the, 60; rich in potash, Bulbs, how nourished, 27. 41. Cow-pox, action of virus of, 127. C. (Crops, rotation of, 54-Favorable effects of, 55Calcareous spar, 90. Principles regulating, 59. Calcium, fluoride of, 53-Chloride of, 64. Cultivation, its benefits, 17-Different methods of, Calculous disorders, 26. 49-Object of, 49. Calico printing, use of cow-dung in, 63. Culture, art of, 43-Of plants, principles of the, Caoutchouc, in plants, 27. 49. Carbon, 10-Afforded to the soil by plants, 27- Cyanic acid, transformation of, 94. Assimilation of, 12-23-Combination of, with Cyanogen, combustion of, 102-Transformation Oxygen, 10-Of decaying substances seldom of, 94. affected by oxygen, 111 —Derived from air, 16 -In decaying wood, 11 —In decaying woody D. fibre, 11 1-In sea-water, 16-Oxide of, formed, Davis, his account of Chinese manure, 65. 92-Quantity ill grain, 14-in land, 14-in Death from nutritious substances, 21 —The source straw, 14-Restored to the soil, 27-Received of life, 36. by leaves, 16-Its affinity for oxygen, 100. Decandolle, his theory of excretion, 55-DifCarbonate of ammonia decomposed by gypsum, forence of his views and those of Macaire34-Of lime in caverns and vaults, 43. Princep, 56. Carbonic acid in the atmosphere, 11-Changes Decay, 98-A source of ammonia, 30-Of wood, in the leaves, 48-Decomposed by plants, 16- 109-Of plants restores oxygen, 29 —and puEmission of, at night, 18-Evaporation of, 20 trefaction, 88. -Evolution from decaying bodies, 100-From Decomposition, 24, 87-Organic, chemical, 88. decaying plants, 29-excrements, 34-humus, Dextrine, 21. 23-respiration, 25 —springs, 29-woody fibre, Diamond, its origin, 11!2. 23-Increase of, prevented, 16-Influence of Diastase, 46-Contains nitrogen, 46. light on its decomposition, 19. Disease, how excited, 120. Carburetted hydrogen with coal, 115. Dog, excrement of the, 59. Caverns, stalactites in, 43. Dung hills, liquid from, 64-Reservoirs, 64. Charcoal condenses ammonia, 35-Experiments of Lukas on, 84 —May replace humus, 27- E. Theory of its action, 27-Promotes growth of Ebony wood, oxygen and hydrogen in, 19. plants, 84. Effete matters separated, 24. Chemical effects of light, 48-Forces can replace Elements of plants, 10-Not generated by orthe vital principle, 26-Processes in nutrition gans, 21. of vegetables, 9-Transformations, 25, 87. Elphinstone, Sir Howard, on soda-ash, as a maCGhemistry, definition of, 9-Organic, what is, 9 nure, 69. -Neglected by botanists, 20; and physiolo- Equilibrium of attractions disturbed, 92. gists, 20. Equisetacne contain silica, 58. China, its agriculture, 65-Collection and use of Eremacausis, 98-Analogous to putrefaction, 130 manure in, 65. -Arrested, 98-Definition of, 98 —Necessary Chloride of calcium, 64-Of nitrogen, 88 -Of to nitrification, 102-Of bodies containing ni. potassium, its effect, 39-Of sodium, its vola- trogen, 102-Of bodies destitute of nitrogen, tility, 42. 100. Clay, burned, advantages of, as a manure, 35. Ether, cenanthic, 105. Clays, potash in, 50. Excrementitious matter, production of, illusClay slate, 53. trated, 25. Coal, formation of, 113-Inflammable gases from, Excrement, animal, its chemical nature, 59-Of 115-Origin of substances in, 112-Of humus, the dog, cow, &c., 59-Influence of, as ma12, 44-Wood or brown, 113. nure, 61. Colours of flowers, 33. Excrements of plants, 55 —Conversion of, into Combustion at low temperatures, 100-Of de- humus, 13-Of man, amount of, 65-Value of, cayed wood, 112-Induction of, 102-Re- 63-Propagation of, 65. moves oxygen, 16 —Spontaneous, 94. Excretion, organs of, 25-Of plants, theory of, 55. Compost manure, 72. Experiments in physiology, object of, 20-Of Concretions from horses, 53. physiologists not satisfactory, 22. Constituents of plants, 10. Contagions, reproduction of, on what dependent, F. 121-Susceptibility to, how occasioned, 125. Fallow, changes from, 52 —Crops, 54-Time, 54. Contagions, how produced, 121-Propagation of, Fattening of animals, 49. 124. Feces, analysis of, 60. Contagious matters, action of, 124, 122, 129 — Ferment, 95, 103. INDEX. 133 Fermentation, 103-Of Bavarian beer, 107-Of Hydrocyanic acid, 23, 88. beor, 107-Gay-Lussac's experiments in, 101 Hydrogen, assimilation of, 28, 29-Properties of, -Of sugar, 95-Of vegetable juices, 95- 10-Excess of, in wood accounted for, 28Vinous, 103-Of wort, 104. Of decayed wood, 111-Of plants, source of, Fertility of fields, how preserved, 61. 28-Peroxide of, 89. Fires, plants on localities of, 52. Hyett, Mr., on nitrate of soda, 69. Fir-wood, analysis of its ashes, 38. Fishes in salt-pans, 41. I. Flanders, manure in, 65. Ice, bubbles of gas in, 20. Fleabane, 54. Indifferent substances, 11. Flesh, effect of salt on, 116. Ingenhouss, his experiments, 18. Flour, bran of, 62. Inorganic compounds, 91-Action of, 115-In Flowers, colours due to ammonia, 33. what they differ from organic, 91. Fluorine in ancient bones, 53. Inorganic constituents of plants, 36-43. Food, effects on products of plants, 47-Of young Iron, oxide of, attracts ammonia, 35. plants, 45 —Transforlnation and assimilation Irrigation of meadows, effect of, 43-57. of, 25. Formation of wood, 47. Formic acid, theory of its formation, 25-From Lactic acid, production of, 98. hydrocyanic acid, 25. Lava, soil from, 51. Fossil resin, origin of, 112. ( Lead, salts of, compounds with organic matter, 1,18. Franconia, caverns in, 43. Leaves, absorb carbonic acid, 16-Ashes of, conFruit, increased, 45-Ripening of, 29-Changes tain alkalies, 52-Cessation of their functions, attending, 45. 24-Change colour from absorption of oxygen, Fulminating silver, 88. 24-Consequence of the production of their green principle, 58-Decompose carbonic acid, G. 48-Their office, 46-Power of absorbing nuGaseous substances in the lungs, effect of, 126. triment, how increased, 24-Quantity of carGasterosteus aculeatus, in salt-pans, 41. bon received by, 16-Contain azotised matter, Gay-TLussac, his experiments, 101. 63. Germany, cultivation in, 61. Lentils, analysis of, 54. Germination of potatoes, 45-Of grain, 46. Life, notion of, 121. Glass as a manure, 63. Light, absence of, its effect, 18-Chemical effects Glue, manure from, 62. of, 48 —Influences decomposition of carbonic Gluten, conversion of, into yeast, 106-110- acid, 19. Decomposition of, 98-Gas from, 103. Lime, phosphate of, 62, 71. Grain, germination of, 46-Manure for, 40-Rust Lucerne, phosphate of lime in, 54-Benefits atin, 75. tending its culture, 58. Granitic soil affords alkalies, 40. Grapes, fermentation of, 103-Juice of, differences in, 106-Potash in, 38. Macaire-Princep, his experiments, 55. Grasses, seeds of, follow man, 41-Silica in, 58- Magnesia, phosphate of, in seeds, 22. Valued in Germany, 57. Manure, 59-70-Animal, yields ammonia, 33Grauwacke, soil from, 50. Artificial, 69-71-Carbonic acid from, 34 —. Growth of plants, conditions for the, 49. Components of, should be known, 49-Of the Guano, 67. Chinese, 65-Effect of, 59-Bone, 62. Gypsum, decomposition of, 34-84-Its influence, Maple juice, ammonia from, 33-Trees, sugar 34-Use of, 64. of, 33. Meadows, irrigation of, 43-57. H. Medicine, action of, remedies in, 6'2. Hay, carbon in, 14-Contains nitrogen, 59- Mellitic acid, 112. Silica, 53. Metallic compounds required by plants, 21. Haystack, effect of lightning upon a, 53. Metamorphosis, 88. Hessian and English weights and measures, 130. Miasm, defined, 127. Hibernating animals, 45. Minerals attract ammonia, 35. Horse, urine of the, 35-Concretions in the, 53. Morbid poisons, 121. Horse dung, action of water upon, 60-Analysis Motion, its influence on chemical forces, 89. of, 60. Mould, vegetable, 112-Conversion of woody Human fieces, analysis of, 60. fibre into, 112. Humate of lime, quantity received by plants, 13. Mouldering of bodies, 113. Humic acid, 12, 31 —Action of, 44-Properties Must, fermentation of, 104. of, 13-Is not contained in soils, 31-Quantity received by plants, 14-Insolubility of, 44. Humus, 11-Action of, 23-Analysis of, 12- Naples, soils of, 52. Erroneous opinions concerning, 17-Action Night-soil, 65. upon oxygen, 43 —Coal of, 44-Conversion of Nile, soil of its vicinity, 57. woody fibre into, 11 0-How produced, 110- Nitrate of soda, as a manure, 69. Its insolubility, 43-Properties of, 13-Re- Nitric acid from ammonia, 103 —animals, 30-_ placed by charcoal, 27-Source of carbonic How formed, 102. acid, 23-Theory of its action, 23-Unneces- Nitrification, 102-Conditioyn for, 103. sary for plants, 27. Nitrogen from animals, 30-Account of, 10M 134 INDEX. Application of substances containing it, 34- Poisoning, superficial, 118-By sausages, 120. Assimilation of, 30-36-Chloride of, 88-, Pompeii; air from, 15-Bones from, 53. Compounds of, 11-peculiarity in 97-In ex- Potash, action of; upon mould, 112-In grapes, crements, 63-From the atmosphere, 30-In 38-Ley of, its effects on excrements, 34plants, 1i-Production of, the object of agri- Presence of, in plants, accounted for, 50-Re. culture, 34-Transformation of bodies con- placed by soda, 38-Required by plants, 22taining, 93-In rice, 33-In solid excrements, Quantity in soils, 50-Silicate of, in soils, 22 63-In urine, 64. -Sources of, 50. Nutrition, conditions essential to, 21 —Tnorganic Potatoes, oil of, 104-Effect of, as food, 47-Gersubstances required in, 21-Superfluous, how mination of, 45-Produce of, increased, 45. employed, 24-Of young plants, 58. Products of transformations, 25. Pus, globules in, 124. O. Purgative effect of salts explained, 117. Oaks, ashes of, 52-Excretions of, 1I8-Dwarf, 23. Pusey, Mr., on nitrate of soda, 69. Oak-wood affords humic acid, 13-Composition Putrefaction, 23, 90-Of animals, 59-Commuof, 110-Mouldered, analysis of, 111. nicated, 121. Odour of substances, 106 —Of gaseous contagious Putrefaction, source of ammonia, 30-of carbonic matter, 127. acid, 34. (Enanthic ether, 105. Putrefying sausages, death from, 120 —their mods Organs of excretion, 25. of action, 120 —Substances, their effect on Organic acids, 11-Decomposition of, 49-Che- wounds, 121-alkaline, 1l23-acid, 123. mistry, 9-Compounds, 29-Compared with inorganic salts in plants, 91. Organised bodies do not generate substances, 24. Rain-water, alkali extracted by, 51. Oxamide, decomposition of, 121. Reduction of oxides, 89. Oxides, metallic, in fir-wood, 38. Reeds and canes require silica, 53. Oxygen, action on alcohol, 99-Absorption of, at Removal of branches, effects of, 45 night, 18-by leaves, 18-respiration, 25 — Reservoirs of dung, 64. plants, 18-wood, 110-Action upon woody Rhine, soils in its vicinity, 57 —Wines, 105. fibre, 11 I —Its action in decomposition, 101- Ripening of fruit, 45. Emitted by leaves, 15-Given to air by land, Root secretions, 55. 28-Extracted from air by mould, 112-In air, Roots absorb, 36 —Emit extractive matter, 5511-Consumption of, 15-In water, 28-Pro- Their office, 43. motes decay, 44-Separated during the formna- Rotation of crops, 54-59. tion of acids, 29-Is furnished by the decomposition of water, 28. S. Saliculite of potash, 99. Saline plants, 40. Perennial plants, how nourished, 46. Salsola kali, 38. Peroxide of hydrogen, 63. Salt, volatilisation of, 43. Petersen and Schodler, their analysis of woods, 19. Salts, absorption of, 39 —Effect of, on the orPhosphates necessary to plants, 53. cganism, 116-Effect of, on flesh, 116-o-n the Phosphate of iron, the probable cause of rust, 75. stomach, 116 —Organic, in plants, 11-in the Phosphoric acid in ashes of plants, 53-Source blood, 11 6-Passage of, through the lungs, 116. of, 53. Salt-works, loss in, 42. Physiologists, their experiments not satisfactory, Saltwort, 41. 22-Neglect of chemistry by, 20. Sand, plants in, 27. Pipe-clay, ammonia in, 35. Sandy soil, decay of wood in, 111. Plants absorb oxygen, 18-Ashes of, salts in, 37 Saturation, capacity of, 36. -Conditions necessary for their life, 22-De- Sausages, poisonous, 120. cay of, a source of oxygen, 29-Decompose Saussure, his experiments on air, 15-On the carbonic acid, 16-Dl)evelopement of, requisites growth of plants, 53. for, 11, 40, 46, 48-Effect of, on rocks, 51- Schubler, his observations on rain, 31. Elements of, 10-Emit acetic acid, 51 —Exha- Sea-water, analysis of, 42-Contains carbon, 16 lation of carbonic acid from, 19-Of a former -Contains ammonia, 42. world, 27 —Formation of their components, Silica in grasses, 53[-In reeds and canes, 53. 29 —Functions of, 16-Improve the air, 17- Silicate of potash in plants, 22-As a manure, Influence of -gases on, 18-of shade, 18-In- 63, 72. organic constituents of, 36 —Life of, connected Silver, carbonate of, action on organic acids, 89with that of animals, 9-Milky-juiced, in bar- Salts, poisonous effects of, 118. ren soils, 27-Organic acids in, 11, 36-salts Sinapis alba, 128. in, 37-Perennial, nourished, 46-Products of, Size of plants proportional to organs of nourishvary, 47-Size of, proportioned to organs of ment, 24. nourishment, 24-Succession of, its advantage, Smell, what, 106. 55 -Vital processes of, 29-Wild, obtain Snow-water, ammonia in, 32. nitrogen from the air, 34-Yield oxygen, 17. Soda may replace potash, 38. Platinum does not decompose nitric acid, 88. Soils, advantage of loosening, 53, 70-Analysis Ploughing, its use, 44. of, 70-Best for meadow-land, 40-Carbon Poisons generated by disease, 115-Inorganic, restored to, 26-Chemical nature of its influ. 117-Peculiar class of, 119-Rendered inert ence, 57-Constituents of, 70-84-.-Exhaustion by heat, 121. of, 51-Ferruginous, improved, 44-Fertile, INDEX. 135 contain phosphoric acid, potash, &c., 82, 83 — Urine, contains nitrogen, 33-Its use as manure, Fertile, of Vesuvius, 51-From lava, 51-Im- 68, 71-Of men, &c., 64-Of horses, 68bibe ammonia, 54-Improved by crops, 54 — Human, analysis of, 64-Of cows, 68-Its Impoverished ky crops, 54-Various kinds of, use in China and Flanders, 33, 65-Of swine, 70, 53. 68. Stagnant water, effect of, 44. Stalactites in caverns, 43. V. Starch, accumulation of, in plants, 45-Compo- Vaccination, its effect, 126. sition of, 29-Developement of plants influ- Vegetable albumen, 33 —Mould, 112-Juices, ferenced by, 45-Effect of, on malt, 26-Product mentation of, 95. of, the life of plants, 18-In willows, 45. Vesuvius, fertile soilof, 51. Staunton, Sir G., on Chinese manure, 65. Vines, new mode of manuring, 86-Juice of, Straw, analysis of, 14. yields ammonia, 33. Struve, experiments of, 51. Vinous fermentation, 103. Substitution of bases, 37. Virginia, early products of its soils, 51. Sussinic acid, 112. Virus, of small pox, 126-Vaccine, 126. Sugar, action of alkalies upon, 92 —acids upon, Vitality, what, 21. 92-Composition of, 95-Carbon in sugar, 14 Vital principle, 26 —Value of the term, 26-How -Contained in the maple-tree, 32 —In clero- balanced in the blood, 122. dendron fragrans, &c., 47-Developement of Vital processes of plants; 56. plants, influence on, 45-Fermentation of, 95 -In beet-roots, 32-Metamorphosis of, 95- W. Organic compounds, all form sugar, 91-Pro- Water, carbonic acid of, absorbed, 16 —Composi. duct of the life of plants, 18-Transformation tion of, 28-Dissolves mould, 112-Plants, of, 93-When produced, 24. their action upon, 20-Rain, contains ammoSulphur, crystallised, diamorphous, 90. nia, 31-required by plants, 11-required by Sulphuric acid, action of, on soils, 70, 84. gypsum, 35-Salt, analysis of, 42. Sulphurous acid arrests decay, 111. Wavellite, 53. Swine, urine of, 68. Wheat, analysis of, 53-Ashes of, used as a maSynaptas, 128. nure, 72-Exhausts, 52-Gluten of, 33 —Why T. it does not thrive on certain soils, 52-In Vir. ginia, 51. Tabasheer, 58. Willows, growth of, 45. Tables of English and Hessian weights, 130. Wine, effect of gluten upon,'106-Fermentation Tannic acid, 29. of, 106-Properties of, 106-Substances in, Tartaric acid, 29 —Converted into sugar, 29 —In 104 —Taste and smell, 105-Varieties of, 105. wine, 105. Woad, decomposition of, 97. Teak tree, salts found in, 53. Wood, charcoal may replace humus, 27-a ma. Teltowa parsnep, 24, 47. nure, 87-Decayed combustion of, 112-AbThenard, his experiments on yeast, 95. sorbs ammonia, 35 —Analysis of, 19-ConverTin, action on nitric acid, 58. sion of, into humus, 110-Decay of, 110Tobacco, juice contains ammonia. 53-Leaves of, Requires air, 11 0-Decomposition of, 87, 97106 —Nitric acid in, 64-In Virginia, 51 -Va- Effect of moisture and air on, 1 10-Elements lue of, proportional to the quantity of potash in of, 110-Formation of, 47-Source of its car. the soil, 72. bon, 14 —Transformation of, 93. Transformation, by heat, 92 —Chemical, 25, 87 Wood coal, how produced, 113 —Analysis of, 114, -Chemical transformations differ from decom- 115. positions, 25-Of acetic acid, 92-Of arrago- Woody fibre, changes in, 110 —Composition of, nite, 90-Of carbonic acid, 48-O-0f meconic 110-Decomposition of, 110-Difference beacid, 92-Not affected by the vital principle, tween it and wood, 110-Formation of, 1826-Explained, 26-Of bodies containing ni- Moist, evolves carbonic acid, 110-Mould from, trogen, 92-Of bodies destitute of nitrogen, 113. 93 —Results of, 26-Of wood, 93-Of cyanic Wormwood, effect of its culture, 41. acid, 94-Of cyanogen, 94-Of gluten, 104. Wort, fermentation of, 107. Transplantation, effect of, 45. Wounds, effect of putrefying substances on, Trees, diseases of, 47 —Require alkalies, 52. 120. U. Y. Ulmin, 12. Yeast, 96 —Destroyed, 104-Experiments on, 96 Urea, converted into carbonate of ammonia, 33- — Formed, 104-Its mode of action, 97-Its In wine, 64. production, 119-Two kinds of, 107. Uric acid, yields ammonia, 64-Transformations of, 64. Urinary calculi, treatment of, 26-Organs, elimi- Z. nate nitrogen, 26. Zinc, decomposition of water with, 29 ANI}IAL CHEM3ISTRY, OR ORGANIC CHEMISTRY IN ITS APPLICATIONS TO PHYSIOLOGY AND PATHOLOGY. _._...... BY JUSTUS LIEBIG, M. D., PH. D. F. R. S., SM. R. I. A., PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF GIESSEN. EDITED FROM THE AUTHOR'S MANUSCRIPT, BY WILLIAM GREGORY, M.D., F R. S. E., M. R. I. A. PROFESSOUI OF MIEDICINE AND CHEMISTRY IN THE UNIVERSITY AND KING'S COLLEGE, ABERDEEN. bilRabel1p ia: T. B PETERSON, No. 98 CHESNUT STREET. TO TIHE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE.. AT the meeting of the British Association in Glasgow, in 1840, I had the honour to present'the first part of a report on the then present state of Organic Chemistry, in which I endeavoured to develope the doctrines of this science in their bearing on Agriculture and Physiology. It affords me now much gratification to be able to communicate to the meeting of the Association for the present year the second part of my labours; in which I have attempted to trace the application of Organic Chemistry to Animal Physiology and Pathology. In the present work an extensive series of phenomena have been treated in their chemical relations; and although it would be presumptuous to consider the questions here raised as being definitely resolved, yet those who are familiar with chemistry will perceive that the only method which can lead to their final resolution, namely, the quantitative method, has been employed. The formulae and equations in the second part, therefore, although they are not to be viewed as ascertained truths, and as furnishing a complete, or the only explanation of. the vital processes there treated of, are yet true in this sense: that being deduced from facts by logical induction, they must stand as long as no new facts shall be opposed to them. When the chemist shows, for example, that the elements of the bile, added to those of the urate of ammonia, correspond exactly to those of blood, he presents to us a fact which is independent of all hypothesis. It remains for the physiologist to determine, by experiment, whether the conclusions drawn by the chemist from such a fact be accurate or erroneous. And whether this question be answered in the affirmative or in the negative, the fact remains, and will some day find its true explanation. I have now to perform the agreeable duty of expressing my-sense of the services rendered to me in the preparation of the English edition by my friend, Dr. Gregory. The distinguished station he occupies as a chemist; the regular education which he has received in the various branches of medicine; and his intimate acquaintance with the German language-all these, taken together, are the best securities that the translation is such as to convey the exact sense of the original; securities, such as are not often united in the same individual. It is my intention to follow this second part with a third, the completion of which, however, cannot be looked for before the lapse of two years. Thisi third part will contain an investigation of the food of man and animals, the analysis of all articles of diet, and the study of the changes which the raw food undergoes in its preparation; as, for example, in fermentation (bread,) baking, roasting, boiling, &c. Already, it is true, many analyses have been made for the proposed work; but the number of objects of. investigation is exceedingly large, and in order to determine with accuracy the absolute value of seed, or of flour, or of a species of fodder, &c., as food, the ultimate analysis alone is not sufficient; there are required comparative investigations, which present very great difficulties. DR. JUSTUS LIEBIG. Giessen, 3d June, 1842. (3) NOTrE. I WOULD beg leave to refer the chemical as well as the physiological reader pdrticularly to the analyses (in Note (27) Appendix) of the animal tissues, which ought to have been referred to on pages 21 and 42, and which at present are only referred to in Note (7.) Since the work was printed, moreover, there has been added, at the end of the Appendix, an interesting paper by Keller (see page 101,) confirming the very important observation of A. Ure, junior, as to the conversion of benzoic acid into hippuric acid in the human body; a fact which, I perceive, by the Philosophical Magazine for June, has also been confirmed by Mr. Garrod, probably at an earlier period than by M. Keller. The reader will perceive that this fact strengthens materially the argument av the Author on the action of remedies. W. G. PREFAC E. BY the application to chemistry of the methods which had for centuries been fbllowed by philosophers in ascertaining the causes of natural phenomena in physics-by the observation of weight and measure —LAvoISIER laid the foundation of a new science, which, having been cultivated by a host of distinguished men, has, in a singularly short period, reached a high degree of perfection. It was the investigation and determination of all the conditions which are essential to an observation,or an experiment, and the discovery of the true principles of scientific research, that protected chemists from error, and conducted them, by a way equally simple and secure, to discoveries which have shed a brilliant light on those natural phenomena which were previously the most obscure and incomprehensible. The most useful applications to the artsto industry, and to all branches of knowledge related to chemistry, sprung from the laws thus established; and this influence was not delayed till chemistry had attained its highest perfection, but came into action with each new observation. All existing experience and observation in other departments of science reacted, in like manner, on the improvement and development of chemistry; so that chemistry received from metallurgy and from other industrial arts as much benefit as she had conferred on them. While they simultaneously increased in wealth, they mutually contributed to the development of each other. After mineral chemistry had gradually attained its present state of development, the labours of chemists took a new direction. From the study of the constituent parts of vegetables and animals, new and altered views have arisen; and the present work is an attempt to apply these views to physiology and pathology. In earlier times the attempt has been made, and often with great success, to apply to the objects of the medical art the views derived from an acquaintance with chemical; observations. Indeed, the great physicians, who lived towards the end of the seventeenth century, were the founders of chemistry, and in those days the only philosophers acquainted with it. The phlogistic system was the dawn of a new day; it was the victory of philosophy over the rudest empiricism. With all its discoveries, modern chemistry has performed but slender services to physiology and pathology; and we cannot be deceived as to the cause of this failure, if we reflect that it was found impossible to trace any sort of relation between the observations made in inorganic chemistry, the knowledge of the characters of the elementary bodies and of such of. their compounds as could be formed in the laboratory, on the one hand, and the living body, with the characters of its constituents, on the other. Physiology took no share in the advancement of chemistry, because for a long period she received from the latter science no assistance in her own development. This state of matters has been entirely changed within five and twenty years. But during this period physiology has also acquired new ways and methods of investigation' within her own province; and it is only-the exhaustion of these sources of A2 5 Vi PRER'A-CHE discovery which has enabled us to look forward to a change in the direction of the labours of physiologists. The time for such a change is now at hand; and a per-t severance in the methods lately followed in physiology would now, from the want, which must soon be felt, of fresh points of departure for researches, render physiology more extensive, but neither more profound nor more solid. No one will venture to maintain that the knowledge of the forms'and of the phenomena of motion in organized beings is either unnecessary or unprofitable. On-the contrary, this knowledge must be considered as altogether indispensable to that of the vital processes. But it embraces only one class of the conditions necessary for the acquisition of that knowledge, and is not of itself sufficient to enable us to attain it. The study of the uses and functions of the different organs, and of their mutual connection in the animal body, was formerly the chief object of physiological researches; but lately this study has fallen into the; back-ground. The greater part of all the modern discoveries has served to enrich comparative anatomy far more than physiology. These researches have yielded the most valuable results in relation to the recognition of the dissimilar forms and conditions to be found in the healthy and in the diseased organism; but they have yielded no conclusions calculated to give us a more profound insight into the essence of the vital processes. The most exact anatomical knowledge of the structure of the tissues cannot teach us their uses; and from the microscopical examination of the most minute reticulations of the vessels we can learn no more as to their functions than we have learned concerning vision from counting the surfaces on the eye of the fly. The most beautiful and elevated problem for the human intellect, the discovery of the laws of vitality, cannot be resolved, nay, cannot even be imagined, without an accurate knowledge of chemical forces; of those forces which do not act at s.ensible distances; which are manifested in the same way as those ultimate causes by which the vital phenomena are determined; and which are invariably found active, whenever dissimilar substances come into contact. Physiology, even in the present day, still endeavours, but always after the fashion of the phlogistic chemists (that is, by the qualitative method,) to apply chemical experience to the removal of diseased conditions; but with all these countless experiments -we are not one step nearer to the causes and the essence of disease. With proposing well-defined questions, experimenters have placed blood, urine, and all the constituents of the healthy or diseased frame, in contact with acids, alkalies, and all sorts of chemical re-agents; and have drawn, from observation of the changes thus produced, conclusions as to their behaviour in the body. By pursuing this method, useful remedies or modes of treatment might by accident be discovered; but a rational physiology cannot be founded on mere re-actions, and the living body cannot be viewed as a chemical laboratory. In certain diseased conditions, in which the blood acquires a viscid consistence, this state cannot be permanently removed by a chemical action on the fluid circulating'in the blood-vessels. The deposit of a sediment from the urine may perhaps, be prevented by alkalies,while their action has not the remotest tendency to remove the cause of disease. Again, when we observe, in typhus, insoluble salts of ammonia in the faces, and a change in the globules of the blood similar to that which may be artificially produced by ammonia, we are not, on that accounts PREFACE. Vil entitled to consider the presence of ammonia in the body as the cause, but only as the effect of a cause. Thus medicine, after the fashion of the Aristotelian philosophy, has formed certain conceptions in regard to nutrition and sanguification; articles of diet have been divided into nutritious and non-nutritious; but these theories, being founded on observations destitute of the conditions most essential to the drawing of just conclusions, could not be received as expressions of the truth. How clear are- now to us the relations of the different articles of food to the objects which they serve in the body, since organic chemistry has applied to the investigation her quantitative method of research! When a lean goose, weighing 4 lbs., gains, in thirty-six days9 during which it has been fed with 24 lbs. of maize, 5 lbs. in weight and yields 3~ lbs. of pure fat, this fat cannot have been contained in the food, ready formed, because maize does not contain the thousandth part of its weight of fat, or of any substance resembling fat. And when a certain number of bees, the weight of which is exactly known, being fed with pure honey, devoid of wax, yield one part of wax for every twenty parts of honey consumed, without any change being perceptible in their health or in their weight, it is impossible any longer to entertain doubt as to the formation of fat from sugar in the animal body. We must adopt the method which has thus led to the discovery of the origin of fat, in the investigation of the origin and alteration of the secretions, as well as in the study of all the other phenomena of the animal body. From the moment that we begin to look earnestly and conscientiously for the true answers to our questions, that we take the trouble, by means of weight and measure, to fix our observations, and express them in- the form of equations, these answers are obtained without difficulty. However numerous our observations may be, yet, if they only bear on one side of a question, they will never enable us to penetrate the essence of a natural phenomenon in its full significance. If we are to derive, any advantage from them, they must be directed to a well defined object; and there must be an organized connection between them. Mechanical philosophers and chemists justly ascribe to their methods of research the greater part of the success which has attended their labours. The result of every such investigation, if it bear in any degree the stamp of perfection, may always be given in few words; but these few words are eternal truths, to the discovery of which numberless experiments and questions were essential. The researches themselves, the laborious experiments and complicated apparatus, are forgotten as soon as the truth is ascertained. They were the ladders, the shafts, the tools, which were indispensable to enable us to attain to the rich vein of ore; they were the pillars and air passages. which protected the mine from water and from foul air. Every chemical or physical investigation, however insignificant, which lays claim to attention~ must in the present day possess this character. From a certain number of observations it must enable us to draw some conclusion, whether it be extended or limited. The imperfection of the method or system of research adopted by physiologists can alone explain the fact, that for the last fifty years they have established so few new and solid truths in regard to a more profound knowledge of the functions of the most important organs, of the spleen, cf the liver, and of the numerous glands Viii PREFACE. of the body; and the limited acquaintance of physiologists with the methods of research employed in chemistry will continue to be the chief impediment to the progress of physiology, as well as a reproach which that science cannot escape, Before the time of Lavoisier, Scheele, and Priestley, chemistry was not more closely related to physics than she is now to physiology. At the present day chemistry is so fused, as it were, into physics, that it would be a difficult matter to draw the line between them distinctly. The connection between chemistry and physiology is the same, and in another half century it will be found impossible to separate them, Our questions and our experiments intersect in numberless curved lines the straight line that leads to truth. It is the points of intersection that indicate to us the true direction; but, owing to the imperfection of the human intellect, these curve lines must be pursued. Observers in chemistry and physics have the eye ever fixed on the object which they seek to attain. One may succeed, for a space, in following the direct line; but all are prepared for circuitous paths. Never doubting of the ultimate success of their efforts, provided they exhibit constancy and perseverance, their eagerness and courage are only exalted by difficulties. Detached observations, without connection, are points scattered over the plain, which do not allow us to choose a decided path. For centuries chemistry presented nothing but these points, and sufficient means were available to fill up the intervals between them. But permanent discoveries and real progress were only made when chemists ceased to make use of fancy to connect them. My object in the present work has been to direct attention to the points of intersection of chemistry with physiology, and to point out those parts in which the sciences become, as it were, mixed up together. It contains a collection of problems, such as chemistry at present requires to be resolved; and a number of conclusions drawn according to the rules of that science from such observations as have been made. These questions and problems will be resolved: and we cannot doubt that we shall have in that case a new physiology and a rational pathology. - Our sounding line, indeed; is not long enough to measure the depths of the sea, but is not on that account less valuable to us: if it assist us, in the mean time, to avoid rocks and shoals, its use is sufficiently obvious. In the hands of the physiologist, organic chemistry must become an intellectual instrument, by means of which he will be enabled to trace the causes of phenomena invisible to the bodily sight; and if among the results which I have developed or indicated in this work, one alone shall admit of a useful application, I shall consider the object for which it was written as fully attained. The path which has led to it will open up other paths; and this I consider as the most important cbject to'be gained. JUSTUTS LIEBIG. Giessen, J.pril, 1842. CONTENTS. PART i. Page The carbon is consumed or burned. 26 Page Vital force, vis vitre, or vitality. 11 True function of the bile... 26 Distinction between animal and vegeta- Amount of bile secreted.27 ble life. 11 Assimilation more energetic in the Assimilation the resultof chemical forces 12 young animal.... 27 Vitality independent of consciousness 12 The butter, sugar, &c., of its food supLaws of the vital force.. 13 port respiration... 28 Conditions of animal life.. 13 The same is true of the class of herbivora 28 Nutrition depends on chemical changes 13 Waste of matter very rapid in carnivora 30 Amount of oxygen inspired by an adult Importance of agriculture to population 30 man. 14 Assimilation less energetic in the carniIt combines with carbon and hydrogen vora...... 31 in the body.... 14 Origin of fat in domesticated animals. 31 The consummption of oxygen varies. 14 Its formation is a source of oxygen. 32 Effect of heat on these variations.. 15 It is formed when oxygen is deficient, The mutual action of oxygen and car- and is a source of animal heat.. 33 bon in the body is the true source of Elements of nutrition and of respiration 35 animal heat.15 Gelatine incapable of serving for nutriThe amount of oxygen regulates that of tion, strictly so called... 35 food.. 16 But it may serve to nourish the gelatiEffects of climate on the appetite. 16 nous tissues.... 35 The process of starvation. 17 Cause of death in starvation and chronic diseases.;... 17 THE METAMORPHOSIS OF TISSUES. Nerves and muscles not the source of Discovery of proteine.... 36 animal body. 18 It is formed by vegetables alone.. 37 Amount of animal heat.. 19 Theory of chymification... 37 Nervous and vegetative life.. 20 Use of the saliva. 38 Nutrition depends on the constituents Source of the nitrogen exhaled from of blood.21 the lungs and skin... 39 Identity of organic composition in fibrine Composition of proteine... 41 and albumen... 1 Composition of the animal tissues. 42 Nutrition in the carnivora the most Gelatine contains no proteine, although simple.22 formed from it.. 42 In the herbivora, depends on the azo- The secretions contain all the elements tized products of vegetables. 22 of the blood. 43 These products identical with the con- Formula of blood and metamorphoses stituents of blood... 22 of bile. 44 The blood of animals is therefore formed Metamorphoses of blood and flesh. 44 by vegetables.. 23 The constituents of the urine derived Uses of the non-azotized ingredients of from the metamorphosed tissues. 45 food..23 Relation of blood or flesh and proteine Changes of the food in the organism of to the secretions and excretions. 45 carnivora.. 24 Formation of gelatine.... 46 Carbon accumulates in the bile. 25 Origin of bile in the carnivora. 47 Nitr,,gen in the urine... 25 Origin of bile in theherbivora.. 47 f2 ix CONTENTS. Page Page Origin of hippuric acid. 48 Phosphorus seems essential to nervous Formation of the chief secretions and matter...... 59 excretions.. 48 PART III. Soda essential to the bile. 49 Relation of urine to bile... 50 1. The phenomena of motion in the Relation of starch to bile 51 animal organism.. 60 Uses of common salt.... 52 2. The same subject, with particular Certain remedies take a share in the reference to the waste and supply or Certain remedies take a share in the vital transformations.change of matter 69.3 Theory of disease... 74 Chief qualities of the blood. 543. Theory of disease... 4 4. Theory of respiration.77 Modus operandi of organic remedies. 55. Theory of respiration 77 All organic poisons contain nitrogen. 56 APPENDIX. Theine identical with caffeine.. -56 Theme* i a with c e Containing the analytical evidence reRelationt of theine and caffeine to bile. 56 ferred to in the sections in which are Theory of their action... 57 described the chemical processes of Theory of the action of the vegetable respiration, nutrition, and the metaalkalies.....57 morphosis of tissues.. 80 Composition and origin of nervous Composition and origin of nervous n the conversion of benzoic acid into matter..57 hippuric acid min the human body, by It is re ated to that of the vegetable alkaf~lies.. 58 ~WXV. Keller..... 101 oalies 58.... 1 Theory of the action of the latter. 59 INDEX.. 103 ORGANIC CHEMISTRY APPLIED TO PHYSIOLOGY AND PATHOLOGY. I. IN the animal ovum, as well as in the While no part of an organized being can seed of a plant, we recognise a certain re- serve as food to vegetables, until, by the markable force, the source of growth, or in- processes of putrefaction and decay, it has crease in the mass, and of reproduction, or assumed the form of inorganic matter, the of supply of the matter consumed; a force animal organism requires, for its support in a state of rest. By the action of external and development, highly organized atoms. influences, by impregnation, by the pre- The food of all animals, in all circumsence of air and moisture, the condition of stances, consists of parts of organisms. static equilibrium of this force is disturbed; Animals are distinguished from vegetaentering into a state of motion or activity, bles by the faculty of locomotion, and, in it exhibits itself in the production of a series general, by the possession of senses. of forms, which, although occasionally The existence and activity of' these disbounded by right lines, are yet widely dis- tinguishing faculties depend on certain ininct from geometrical forms, such as we ob- struments which are never found in vegetaserve in crystallised minerals. This force is bles. Comparative anatomy shows, that called the vital force, or viz vitce vitality, the phenomena of motion and sensation deThe increase of mass in a plant is deter- pend on certain kinds of apparatus, which mined by the occurrence of a decomposition have no other relation to eacli other than which takes place in certain parts of the this, that they meet in a common centre. plant under the influence of light-and heat. The substance of the spinal marrow, the In the vital process, as it goes on in nerves, and the brain, is in its composition, vegetables, it is exclusively inorganic matter and in its chemical characters, essentially which undergoes this decomposition; and distinct from that of which cellular subif, with the most distinguished mineralo- stance, membranes, muscles, and sliin are gists,' we consider atmospherical air and composed. certain other gases as'minerals, it may be Every thing in'the animal organism, to said that the vital process in vegetables ac- which the name of mnotion can be applied, complishes the transformation of mineral proceeds from the nervous apparatus. The substances into an organism endued with phenomena of motion in vegetables, the life; that the mineral becomes part of an circulation of the sap' for example, observed organ possessing vital force. in many of the characea, and the closing ot The increase of mass in a living plant flowers and leaves, depend on physical and implies that certain component parts of its mechanical causes. A: plant is destitute of nourishment become component parts of nerves. Heat and light are the remote the plant; and a comparison of the chemical causes of motion in vegetables; but in anicomposition of the plant with that of its mals we recognise in the nervous apparatus nourishment, makes krnown to us, with a source of power, capable of reneging positive certainty, which of the component itself at every moment of their existence. parts of the latter have been assimilated, and While the assimilation of food in vegetawhich have been rejected. bles, and the whole process of their formaThe observations of vegetable physiolo- tion, are dependant on certain external ingists and the researches of chemists have fluenrces which produce motion, the deve mutually contributed to establish the fact, lopment of the animal organism is, to a that the growth and development of vege- certain extent, independent of these external tables depend on the elimination of oxygen, influences, just because the animal body which is separated from the other compo- can produce within itself that source of mronent parts of their nourishment. tion which is indispensable-to the vital proIn contradiction to vegetable life, the life cess. of animals exhibits itself in the continual Assimilation, or the process of formation absorption of the oxygen of the air, and its and growth-in other words, the passage of combination with certain component parts matter from a state of motion to that of rest of the anima, body -goes on in the same way in animals and 11 12 ANIMAL CHEMISTRY. n vegetables. In'both, the same cause de- The efforts of philosophers, constantly re termines the increase of mass. This con- newed, to penetrate the relations of the soul stitutes the true vegetative life, which is to animal life, have all along retarded the carried on without consciousness. progress of physiology. In this attempt The activity, of vegetative life manifests men left the province of philosophical reitself, in vegetables, with the aid of external search for that of fancy; physiologists, carinfluences; in animals, by means of in- ried away by imagination, were far from fluences produced within their organism. being acquainted with the laws of purely Diogestion, circulation, secretion, are no animal life. None of them had a clear condoubt under the influence of the nervous ception of the process of development and system; but, the force which gives to the nutrition, or of the true cause of death. germ, tae leaf, and the radical fibres of the They professed to explain the most obscure vegetable'the same wonderful properties, is psychological phenomena, and yet they were the same as that residing in the secreting unable to say what fever is, and in what membranes and glands of animals, and way quinine acts in curing it. which enables every animal organ to per- For the purpose of investigating the laws form its own proper function. It is only of vital motion in the animal body, only one the source of motion that differs in the two condition, namely, the knowledge of the great classes of organized beings. apparatus which serves for its production, While the organs of the vital motions are was ascertained; but the substance of the never wanting in the lowest orders of ani- organs, the changes which food undergoes mals, as in the impregnated germ of the in the living body, its transformation into ovum, in which they are developed first of portions of organs, and its reconversion into all, we find, in the higher orders of animals, lifeless compounds, the share which the atpeculiar organs of feeling and sensation, of mosphere takes in the processes of vitality; consciousness and of a higher intellectual all these foundations for future conclusions existence. were still wanting. Pathology informs us that the true vege- What has the soul, what have conscioustative life is in no way dependant on the ness and intellect to do with the developpresence of this apparatus; that the process ment of the human foetus, or the foetus in a of nutrition proceeds in those parts of the fowl's egg? not more, surely, than with the body where the nerves of sensation and development of the seeds of a plant. Let voluntary motion are paralysed, exactly in us first endeavour to refer to their ultimate the same way as in other parts where these causes those phenomena of life which are nerves are in the noimal condition; and, on, not physiological; and let us beware of the other hand, that the most energetic voli- drawing conclusions before we have a tion is incapable of exerting any influence groundwork. We know exactly the meon the contractions of the heart, on the mo- chanism of the eye; but neither anatomy tion of the intestines, or on the processes nor chemistry will ever explain how the of secretion. rays of light act on consciousness, so as to The higher phenomena of mental exist- produce vision. Natural science has fixed ence cannot, in the present state of science, limits which cannot be passed; and it must be referred to their proximate, and still less always be borne in mind that, with all our to their ultimate causes. We only know of discoveries, we shall never know what light, them, that they exist; we ascribe them to electricity, and magnetism are in their esan immaterial agency, and that, in so far as sence, because, even of those things which its manifestations are connected with matter, are material, the human intellect has only an agency entirely distinct from the vital conceptions. We can ascertain, however, force, with which it has nothing in common. the laws which regulate their motion and It cannot be denied that this peculiar force rest, because these are manifested in phenoexercises a certain influence on the activity mena. In like manner the laws of vitality, of vegetative life, just as other immaterial and of all that disturbs, promotes, or alters agents, such as Light, Heat, Electricity, and it, may certainly be discovered, although we Magnetism do; but this influence is not of shall never learn what life is. Thus the a determinative kind, and manifests itself' discovery of the laws of gravitation and of only as an acceleration, a retarding, or a dis- the planetary motions led to an entirely new turbance of the process of vegetative life. In conception of the cause of these phenomena. a manner exactly analogous, the vegetative This conception could not have been formed life re-acts on the conscious mental existence. in all its clearness without a knowledge of There are thus two forces which are found phenomena out of which it was evolved; in activity together; but consciousness and for, considered by itself, gravity, like light'intellect may be absent in animals as they to one born blind, is a mere word, devoid of are in living vegetables, without their vitality meaning. being otherwise affected than by the want The modern science of physiology has of a peculiar source of increased energy or left the track of Aristotle. To the eternal of disturbance. Except in regard to this, advantage of science, and to the benefit of all the vital chemical processes go on pre- mankind, it no longer invents a horror vacui, ciselv in the same way in inan and in the a quinta essentia, in order to furnish credulower animals. ]ous hearers with solutions and explanations CHEMICAL CHANGES. 13 of phenomena, whose true connection with of these different conditions of tae vital force others, whose ultimate cause is still un- are chemical forces. known. The cause of the state of rest is a resistIf we assume that all the phenomena ex- ance, determined by a force of attraction hibited by the organism of plants and ani- (combination,) which acts between the mals are to be ascribed to a peculiar cause, smallest particles of matter, and is manidifferent in its manifestations from all other fested only when these are in actual contact, causes which produce motion or change of or at infinitely small distances. condition; if, therefore, we regard the vital To this peculiar kind of attraction we force as an independent force, then, in the may of course apply different names; but phenomena of organic life, as in all other the chemist calls it affinity. phenomena ascribed to the action of forces, The cause of the state of motion is to be we have the statics, that is, the state of equi- found in a series of changes which the food librium determined by a resistance, and the undergoes in the organism, and these are dynamics, of the vital force. the results of processes of decomposition, to All the parts of the animal body are pro- which either the food itself, or the structures duced from a peculiar fluid, circulating in formed from it, or parts of organs, are subits organism, by virtue of an influence resid- jeected. ing in every cell, in every organ, or part of The distinguishing character of vegetable an organ. Physiology teaches that all parts life is a, continued passage of matter from of the body were originally blood; or that the state of motion to that of static equiliat least they were brought to the growing brium. While a plant lives, we cannot organs by means of this fluid. perceive any cessation in its growth; no The most ordinary experience farther part of an organ in the plant diminishes in shows, that at each moment of life, in the size. If decomposition occur, it is the reanimal organism, a continued change of sult of assimilation. A plant produces matter, more or less accelerated, is going within itself no cause of motion; no part on; that a part of the structure is transformed of its structure, from any influence residing into unorganized matter, loses its condition in its organism, loses its state of vitality, of life, and must be again renewed. Physi- and is converted into unorganized, amorology has sufficiently decisive grounds for phous compounds; in a word, no waste the opinion, that every motion, every mani- occurs in vegetables. Waste, in the animal festation of force, is the result of a transfor- body, is a change in the state or in the mation of the structure or of its substance; composition of some of its parts, and consethat every conception, every mental affec- quently is the result of chemical actions. tion, is followed by changes in the chemical The influence of poisons and of remedial nature of the secreted fluids; that every agents on the living animal body evidently thought, every sensation, is accompanied by shows that the chemical decompositions and a change in the composition of the sub- combinations in the body, which manifest stance of the brain. themselves in the phenomena of vitality, In order to keep up the phenomena of life may be increased in intensity by chemical in animals, certain matters are required, forces of analogous character, and retarded parts of organisms, which we call nourish- or put an end to by those of opposite chament. In consequence of a series of altera- racter; and that we are enabled to exercise tions, they serve either for the increase of an influence on every part of an organ by the mass (nutrition,) or for the supply of means of substances possessing a wellthe matter consumed (reproduction,) or, defined chemical action. finally, for the production of force. As, in the closed galvanic circuit, in conIL. If the first condition of animal life be sequence of certain changes which an inorthe assimilation of what is commonly called ganic body, a metal, undergoes when placed aourishment, the second is a continual in contact with an acid, a certain something absorption of oxygen from the atmos- becomes cognizable by our senses, which phere. we call a current of electricity; so, in the Viewed as an object of scientific research, animal body, in consequence of transformaanimal life exhibits itself in a series of- tions and changes undergone by matter phenomena, the connection and recurrence previously constituting a part of the organof which are determined by the changes ism, certain phenomena of motion and which the food and the oxygen absorbed activity are perceived, and these we call from the atmosphere undergo in the organ- life, or vitality. ism under the influence of the vital force. The electrical current manifests itself in All vital activity arises from the mutual certain phenomena of' attraction and repulaction of the oxygen of the atmosphere and sion, which it excites in other bodies nathe elements of the food. turally motionless, and by the phenomena In the processes of nutrition and repro- of the formation and decomposition of cheduction, we perceive the passage of matter mical compounds, which occur every where, from the state of motion to that of rest when the resistance is not sufficient to arrest (static equilibrium;) under the influence of the current. mhe nervous system, this matter enters again It is from this point of view, and from no into a state of motion, The ultimate causes other, that chemistry ought to contemplate'3 14 ANIMAL CHEMISTRY. the phenomena of life. Wonders surround sion is inevitable, that the body of a man us on every side. The formation of a who daily takes into the system 324 oz. of crystal, of an octahedron, is not less incom- bxygen, must receive daily in the shape of prehensible than the production of a leaf or nourishment, as much carbon and hydrogen of a muscular fibre; and the production as would suffice to supply 24 lbs. of blood of vermilion from mercury and sulphur is with these elements; it being presupposed as much an enigma as the formation of an that the weight of the body remains uneye from the substance of the blood. changed, and that it retains its normal conThe first conditions of animal life are nu- dition as to health. tritious matters and oxygen, introduced into This supply is furnished in the food. the system. From the accurate determination of the At every moment of his life man is taking quantity of carbon daily taken into the sysoxygen- into his system, jby means of the tem in the food, as well as of that propororgans of respiration; no pause is observ- tion of it which passes out of the body in able while life continues. the freces and urine, unburned, that is, in The observations of physiologists have some form in which it is not combined with shown that the body of an adult man, sup- oxygen, it appears, that an adult, taking plied with sufficient food, has neither in- moderate exercise, consumes 13.9 oz. of creased nor diminished in weight at the end carbon daily. (3) of twenty-four hours; yet the quantity of These 13-9 oz. of carbon escape through oxygen taken into the system during this the skin and lungs as carbonic acid gas. period is very considerable. For conversion into carbonic acid gas, According to the experiments of Lavoisier, 1 3-o oz. of carbon require 37 oz. of oxygen. an adult man takes into his system, from the According to the analyses of Boussingault atmosphere, in one year, 746 lbs., according (Ann. de Ch. et de Ph. LXXI. p. 136) a to Menzies, 837 lbs. of oxygen; yet we find horse consumes in twenty-four hours 97shis weight, at the beginning and end of the oz. of carbon, a milk cow 69-r- oz. The year, either quite the same, or differing, quantities of carbon here mentioned are one way or the other, by at most a few those given off from the bodies of these anipounds. (1)- mals in the form of carbonic acid; and it What, it may be asked, has become of appears from them that the horse consumes, the enormous weight of oxygen thus intro- inr converting carbon into carbonic- acid, 13 duced, in the course of a year into the lbs. 34 oz. in twenty-four hours, and the human system? millk cow 11 lbs. 103 oz. of oxygen in the This question may be answered satisfac- same time. (4) torily; no part of this oxygen remains in the Since -no part of the oxygen taken into system; but it is given out again in the form the system is again given off in any other of a compound of carbon or of hydrogen. form but that of a compound of carbon or The carbon and hydrogen of certain parts hydrogen; since, farther, the carbon and hyof the body have entered into'combination'drogen given off are,replaced by carbon and with the oxygen introduced through the hydrogen supplied in the food, it is clear lungs and through the skin, and have been' that the amount of nourishment required by given out in the forms of carbonic acid gas the animal body must be in a direct ratio to and the vapour of water. the quantity of oxygen taken into the At every moment, with every expiration, system. certain quantities of its elements separate Two animals, which in equal times take from' the animal organism, after having en- up by means of the lungs and skin unequal tered into combination, within the body, quantities of oxygen, consume quantities of with the oxygen of the atmosphere. the same nourishment which are unequal in If we assume, with Lavoisier and Seguin, the same ratio. in order to obtain a foundation for our cal- The consumption of oxygen in equal culation, that an adult man receives into his times may be expressed by the number of system daily 324oz. (46,037 cubic inches=' respirations; it is cleat that, in the same in 15,661 grains, French weight) of oxygen, dividual, the quantity of nourishment reand that the weight of the whole mass of quired must vary with the force and numhis blood, of which 80 per cent. is water, is ber of the respirations. 24 lbs.; it then appears, from the known A child, in whom the organs of respiration composition of the blood, that, in order to are naturally very active, requires food ofconvert the whole of its carbon and hydro- tener than an adult, and bears hunger less gen into carbonic acid and water, 64,103 easily. A bird, deprived of food, dies on the grains of oxygen are required. This quan- third day, while a serpent, with its sluggish tity will be taken into the system of. an adult respiration, can live without food three in four days five hours. (2) months and longer. Whether this oxygen enters into combi- The number of respirations is smaller in nation with the elements of the blood, or a state of rest than during exercise or work. with other parts of the body containing car- The quantity of food necessary in both conbon and hydrogen, in either case the conclu- ditions must vary in the same ratio. An excess of food is incompatible with ~ The Numbers refer tO the Appendix. deficiency in respired oxygen, that is. with SOURCE OF ANIMAL HEAT.-RESPIRATION. 15 deficl.ent exercise; just as violent exercise, sess within themselves a source of heat inwhich implies an increased supply, of food, dependent of surrounding objects. is incompatible with weak digestive organs. This truth applies to all animals, and exIn either case the health suffers. tends, besides, to the germination of seeds, But the quantity of oxygen inspired is to the flowering of plants, and to the maturaalso affected by the temperature and density tion of fruits. of the atmosphere. It is only in those parts of the body to The capacity of the chest in an animal is which arterial blood, and with it the oxygen a constant quantity. At every respiration a absorbed in respiration, is' conveyed, that quantity of air enters, the volume of which heat- is produced. Hair, wool, or feathers, may be considered as uniform; but its do not possess an elevated temperature. weight, and consequently that of the oxygen This high temperature of the animal it contains, is not constant. Air is expanded body, or, as it may be called, disengagement by heat, and contracted by cold, and there- of heat, is uniformly and under all circumfore equal volumes of hot and cold air con- stances the result of the combination of a tain unequal weights of oxygen., In sum- combustible substance with oxygen.' mer, moreover, atmospherical air contains In whatever way carbon may combine aqueous vapour, while in winter it is dry; with oxygen, the act of combination cannot the space occupied by vapour in the warm take place without the disengagement of air is filled up by air itself in winter; that heat. It is a matter of indifference whether is, it contains, for the same volume, more the combination take place rapidly or slowly, oxygeq in winter than in summer. at a high. or at a low temperature; the In summer and in winter, at the pole amount of heat liberated' is' a constant and at the equator, we respire an equal vo- quantity. lume of air; the cold, air is warmed during The carbon of the food, which is conrespiration, and acquires the temperature of verted into carbdnic acid within the body, the body. To introduce into the lungs a must give out exactly as much heat as if it given volume of oxygen, less expenditure had been directly burnt in the air or in oxyof force is necessary in winter than in sum- gen gas; the only difference is, that the mer; and for the same expenditure of force, amount of heat produced is diffused over more oxygen is inspired in winter. unequal times. In oxygen, the combustion It is obvious, that in an equal number of is more rapid, and the heat more intense; respirations we consume more oxygen at in air it is slower, the temperature is not so the level of the sea than on a mountain. high, but it continues longer. The quantity both of oxygen inspired and It is obvious that the amount of heat libeof carbonic acid expired, must, therefore, rated must increase or diminish with the vary with the height ofthe barometer. quantity of oxygen introduced in equal. The oxygen taken into the system is given times by respiration. Those animals which out again in the same forms,' whether in respire frequently, and consequently, consummer or in winter; hence we expire sume much oxygen, possess a higher temmore carbon in cold weather, and when the. perature than others, which, with a body of barometer is high, than we do in warm equal size to be heated, take into the system weather; and we must consume more or less oxygen. The temperature of a child less carbon in our food in the same propor- (102~0) is higher than that of an adult tion; in Sweden more than in Sicily; and (99'50). That of birds (1040 to 105.40) is in our more temperate climate a full eighth higher than that of quadrupeds (98350 to more in winter than in summer. 100-40) or than that of fishes or amphibia, Even when we consume equal weights whose proper temperature is from 2'70 to of food in cold and warm countries, infinite 36~0 higher than that of the medium in wisdom has so frranged, that the articles of which they live. All animals, strictly food in different climates are most unequal speaking are warm-blooded; but in those in the proportion of carbon they contain. only which possess lungs is the temperature The fruits on which the natives of the' of the body quite independent of the sursouth prefer to feed do not in the fresh state rounding medium. (5) contain more than 12 per cent. of carbon, The most trustworthy observations prove while the bacon and train oil used by the that in all climates, in the temperate zones inhabitants - of the arctic regions contain as well as at the equator or the poles, the from 66 to 80 per cent. of carbon. temperature of the body in man, and in It is no difficult matter, in warm climates, what are commonly called warm-blooded to study moderation in eating, and men can animals, is invariably the same; yet how bear hunger for a long time under the equa- different are the circumstances under which tor; but cold and hunger united very soon they live exhaust the body. The animal body is a heated mass, which The mutual action between the elements bears the same relation to surrounding obof the food and the oxygen conveyed by the jects as any other heated mass. It receives circulation of the blood to every part of the heat when the surrounding objects are hotter, body is THE SOURCE OF ANIMAL HEAT. it loses heat when they are' colder than III. All living creatures, whose existence itself. depends on the absorption of oxygen, pos- We know that the rapidity of cooling in. 16 ANIMAL CHEMISTRY. creases with the difference between the tem- body, urges man to labourious efforts in perature of the heated body and that of the order to furnish the means of resistance to surrounding mediumn; that is, the colder the its action, while, in hot climates, the necessurrounding medium the shorter the time sity of labour to provide food is far less required for the cooling of the heated body, urgent. How unequal, then, must be the loss of Our clothing is merely an equivalent for heat in a man at Palermo, where the exter- a certain amount of food. The more warmly nal temperature is nearly equal to that of the we are clothed the less urgent becomes the body, and in the polar regions, where the appetite for food, because the loss of heat external temperature is from 70~ to 900 by cooling, and consequently the amount lower. of heat to be supplied by the food, is diYet, notwithstanding this extremely un- minished. equal loss of heat, experience has shown If we were to go naked, like certain savage that the blood of the inhabitant of the arctic tribes, or if in hunting or fishing we were circle has a temperature as high as that of exposed to the same degree of cold as the the native of the south, who lives in so dif- Samoyedes, we should be able with ease to ferent a medium. consume 10 lbs. of flesh, and perhaps, a This fact, when its true significance is per- dozen of tallow candles into the bargain, ceilved, proves that the heat given off to the daily, as warmly clad travellers have resurrounding medium is restored within the lated with astonishment of these people! body with great rapidity. This compensa- We should, then, also be able to take the tion takes place more rapidly in winter than same quantity of brandy or train oil without in summer, at the pole than at the equator. bad effects, because the carbon and hydrogen Now, in different climates the quantity of of these substances would only suffice to oxygen introduced into the system of respi- keep up the equilibrium between the exterration, as has been already shown, varies nal temperature and that of our bodies. according to the temperature of the exter- According to the preceding expositions, nal air; the quantity of inspired oxygen in- the quantity of food is regulated by the creases with the loss of heat by external number of respirations, by the temperature cooling, and the quantity of carbon or hydro- of the air, and by the amount of heat given gen necessary to combine with this oxygen off to the surrounding medium. must be increased in the same ratio. No isolated fact, apparently opposed to It is evident that the supply of the heat this statement, can' affect the truth of this lost by cooling is effected by the mutual natural law. Without temporary or permaaction of the elements of the food and the nent injury to health, the Neapolitan cannot inspired oxygen, which combine together. take more carbon and hydrogen in the shape To make use of a familiar, but not on that of food than he expires as carbonic acid account a less just illustration, the animal and water; and the Esquimnaux cannot exbody acts, in this respect, as a furnace, pire more carbon and hydrogen than he which we supply with fuel. It signifies takes into the system as food, unless in a nothing what intermediate forms food may state of disease or of starvation. Let us exassume, what changes it may undergo in the amine these states a little more closely. body, the last change is' uniformly the con- The Englishman in Jamaica sees with version of its carbon into carbonic acid, and regret the disappearance of his appetite, of its hydrogen into water; the unassimila- previously a source of frequently recurring ted nitrogen of the food, along with the un- enjoyment; and he succeeds by the use of burned or unoxidised carbon, is expelled in cayenne pepper and the most powerful the urine or in the solid excrements. In stimulants, in enabling himself to take as order to keep up in the furnace a constant much food as he was accustomed to eat at temperature, we must vary the supply of home. But the whole of the carbon thus fuel according to the external temperature, introduced into the system is not consumed; that is, according to the supply of oxygen. the temperature of the air is too high, and In the animal body the food is the fuel; the oppressive heat does not allow him to with a proper supply of oxygen we obtain increase the number of respirations by active the heat given out during its oxidation or exercise, and thus to proportion the waste combustion. In winter, when we take to the amount of food taken; disease of exercise in a cold atmosphere, and when some kind, therefore, ensues. consequently the amount of inspired oxygen On the other hand, England sends her increases, the necessity for food containing sick, whose diseased digestive organs have carbon and hydrogen increases in the same in a greater or less degree lost the power of ratio; and by gratifying the appetite thus bringing the food into that state in which it excited, we obtain the most efficient protec- is best adapted for oxidation, and therefore, tion: against the most piercing cold. A furnish less resistance to the oxidising starving man is soon frozen to death; and agency of the atmosphere than is required every one knows that the animals of prey in their native climate, to southern regions, in the arctic regions far exceed in voracity where the amount of inspired oxygen is those of the torrid zone. diminished in so great a proportion; and In cold and temperate climates, the air, the result, an improvement in the health, which incessantly strives to consume the is obvious. The diseased organs of diges EFFECTS OF STARVATION. 17 tion have sufficient power to place the di- whatever is presented to it; and the deficiminished amount of food in equilibrium ency of hydrogen is the only reason why with the inspired oxygen; in the colder carbonic acid is the chief product; for, at climate, the organs of respiration them- the temperature of the body, the affinity of selves would have been consumed in fur- hydrogen for oxygen far surpasses that of nishing the necessary resistance to the action carbon fobr the same element. of the atmospheric oxygen. We know, in fact, that the graminivora In our climate, hepatic diseases, or those expire a volume of carbonic acid equal to arising from excess of carbon, prevail in that of the oxygen inspired, while the carnisummer; in winter, pulmonic diseases, or vora, the only class of' animals whose food those arising from excess of oxygen, are contains fat, inspire more oxygen than is mnore frequent. equal in volume to the carbonic acid exThe, cooling. of the body, by whatever pired. Exact experiments have shown:, cause it may be produced, increases the that in many cases only half the volume of amount of food necessary. The mere ex- oxygen is expired in the form of carbonic posure to the open air, in a carriage or on acid. These observations cannot be gainthe deck of'a ship, by increasing radiation said, and are far more convincing than those and vaporization, increases the loss of heat, arbitrary and artificially produced phenoand compels us to eat more than usual. mena, sometimes called experiments; expeThe same is true of those who are accus- rinents which, made as too often they are, tomed to drink large quantities of cold without regard to the necessary and natural water, which is given off at the temperature conditions, possess no value, and may be of the body, 98.50. It increases the appe- entirely dispensed with; especially when, as tite, and persons of weak constitution find in the present case, nature affords the opit necessary, by continued exercise; to sup- portunity for observation, and when we ply to the system the oxygen required to, make a rational use of that opportunity. restore the heat abstracted by the cold In the progress of starvation, however, it water. Loud and long continued speaking, is not onlyr the fat which disappears, but the crying of infants, moist air, all exert a also, by degrees, all such of the solids as decided and appreciable influence on the are capable of being dissolved. In the amount of food which is taken. wasted bodies of those who have suffered IV. In the foregoing pages, it has been starvation, the muscles are shrunk and unassumed that it is especially carbon and naturally soft, and have lost their contractihydrogen which, by combining with oxy- lity; all those parts, of the body which were gen, serve to produce animal heat. In fact, capable of entering into the state of motion, observation proves that the hydrogen of the have served to protect the remainder of the food plays a not less important part than the frame from the destructive influence of the carbon. atmosphere. Towards the end, the partiThe -whole process of respiration appears cles of the brain begin to undergo the process most clearly developed, when we consider of oxidation, and delirium, mania, and death the state of a man, or other animal, totally close the scene; that is to say, all resistance deprived -of food. to the oxidising power of the atmospheric The first effect of starvation is the disap- oxygen ceases, and the chemical process of pearance of fat, and this fat cannot be traced eremacausis, or decay, commences, in which in the urine or in the scanty faces. Its car- every part of the body, the bones excepted, bon and hydrogen have been given off enters into combination with oxygen. through the skin and lungs in the form of The time which is required to cause death oxidised products; it is obvious that they by starvation depends on the amount of fat have served to.support respiration. in the body, on the degree of exercise, as' in In the case of a starving man, 32 oz. of labour or exertion of any kind, on the temoxygen enter the system daily, and are perature of' the air, and finally, on the pregiven out again in combination with a part sence or absence of water. Through the of his body. Currie mentions the case of skin and lungs there escapes a certain quanan individual who was unable to swallow, tity of water, and as the presence of water and whose body lost 100 lbs. in weight dur- is essential'to the continuance of the vital ing a month; and, according to Martell motions, its dissipation hastens death. Cases (Trans. Linn. Soc., vol. xi. p. 411,) a fat have occurred, in which a full supply of pig, overwhelmed in a slip of earth, lived water being accessible to the sufferer, death 160 days without food, and was found to has not occurred, till after the lapse of have diminished in weight, in that time, twenty days. In one case, life was susmore than 120 lbs. The whole history of tained in this way for the period of sixty hybernating animals, and the well esta- days. blished facts of the periodical accumulation, In all chronic diseases death is produced in various animals, of fat, which, at other by the same cause, namely, the chemical periods, entirely disappears, prove that the action of the atmosphere. When those oxygen, in the respiratory process, con- substances are wanting, whose function in sumes, without exception, all such sub- the organism is to support the process of stances as are capable of entering into respiration; when the diseased organs are combination with it. It combines with incapable of performing their proper fuac3 B2 18 ANIMAL CHEMISTRY. t;lon of producing these substances; when agency, it means nothing else than to derive they have lost the power of transforming the presence of motion, the manifestation of the food into that shape in which it may, a force, from nothing. But no force, no by entering into combination with the oxy- power can come of nothing. gen-ot the air, protect the system from its No one will seriously deny the share influence, then, the substance of the organs which the nervous apparatus has in the themselves, the fat of the body, the sub- respiratory process; for no change of condistance of the muscles, the nerves, and the tion can occur in the body without the brain, are unavoidably consumed." nerves; they are essential to all vital motions. The true cause of death in these cases is Under their influence, the viscera produce the respiratory process, that is, the action of those compounds, which, while they protect the atmosphere.' the organism from the action of the oxygen A deficiency of food, and the want of of the atmosphere, give rise to animal heat; power to convert the food into a part of the and when the nerves cease to perform their organism, are both, equally a want of resist- functions, the whole process of the action ance; and -this is the negative cause of the of oxygen must assume another form. cessation of the vital process. The flame When the pons-Varolii is cut through in the is extinguished, because the oil is consumed; dog, or when a stunning blow is'inflicted on and it is the oxygen of the air which has the back of the head, the animal continues consumed it. to respire for some time, often more rapidly In many diseases substances are produced than in the nominal state; the frequency which are incapable of assimilation. By of the pulse at first rather increases than the mere deprivation of food, these sub- diminishes, yet the animal cools as rapidly stances are removed from the body without as if sudden death had occurred. Exactly leaving a trace behind; their elements have similar observations have been made on the entered into combination with the oxygen cutting of the spinal chord, and of the par of the air. vagum. The respiratory motions continue From the first moment that the function for a time, but the oxygen does not meet of the lungs or of the skin is interrupted or with those substances with which, in the disturbed, compounds, rich in carbon, ap- normal state, it would have combined; bepear in the urine, which.acquires a brown cause the paralysed viscera will no longer colour. Over the whole surface of the body furnish them. The singular idea that the oxygen is absorbed, and combines with all nerves produce animal heat, has obviously the substances which offer no, resistance to arisen from the notion that the inspired oxyit. In those parts of the body where the gen combines with carbon, in the blood access of oxygen is impeded; for example,' itself; in which case the temperature of the in the armpits, or in the soles of the feet, body, in the above experiments, certainly, peculiar compounds are given out, recog- ought not to have sunki But, as we shall nisable by their appearance, or by their afterwards see, there cannot be a more erroodour. These compounds contain much neous conception than this. carbon. As by the division of the pneumogastric Respiration is the falling weight, the bent nerves the motion of the stomach and the spring, which keeps the clock in motion; secretion of the gastric juice are arrested, the inspirations and expirations are the and an immediate check is thus given to the strokes of the pendulum which regulate it. process of digestion, so the paralysis of the In our ordinary timepieces, we know with organs of vital motion in the abdominal vismathematical accuracy the effect produced cera affects the process of respiration. These on their rate of going, by changes in the processes, are most intimately connected; length of the pendulum, or in the external and every disturbance of the nervous system temperature. Few, however, have a clear or of the nerves of digestion re-acts visibly conception of the influence of air and ternm- on the process of respiration. perature on the health of the human body; The observation has been made, that heat and yet the research into the conditions ne- is produced by the contraction of the muscessary to keep it in the nominal state, is not cles, just as in a piece of caoutchouc, which, more difficult than in the case of a clock. when rapidly drawn out, forcibly contracts V. The want of a just conception of force again, with disengagement of heat. Some and effect, and of the connection of natural have gone so far as to ascribe a part of the phenomena, has led chemists to attribute q animal heat to the mechanical motions of part of the heat generated in the animal the body, as if these motions could exist body to the action of the nervous system. without an expenditure of force consumed If this view exclude chemical action, or in producing them; how then, we may asK, changes in the arrangement of the elemen- is this force produced? tary particles, as a condition of nervous By the combustion of carbon, by the solution of a metal in an acid, by the combination of the two electricities, positive and * For an account of w;hat really takes place in negative, by the absorption of light, and even this process, I refer to the considerations on the by e means by which the change of matter is effected bythe rubbing of two solid bodies together in the body of the carnivora, which will be found with a certain degree f rapidity, heat may farther on. be prodaeelt GREAT AMOUNT OF ANIMAL HEAT. 19 By a number of causes, in appearance different effects may be produced. The entirely distinct, we can thus produce one cause of this phenomena is magnetism; the and the same'effect. In combustion and in cause of the magnetic phenomena is to be the production of galvanic electricity, we found in-the electrical current; and the ultihave a change of condition in material par- mate cause of the electrical current is found ticles; when heat is produced by the ab- to be a chemical change, a chemical action. sorption of light or by friction, we have the There are various causes by which force conversion of one kind, of motion into an- or motion mia be produced. A bent spring, other, which affects our senses differently. a current of air, the fall of water, fire apIn all such cases we have a something plied to a boiler, the solution of a metal in given, which' merely takes another form; an acid,-all these different causes of -mo — in all we have a force and its effect. By tion may be made to produce the same means of the fire which heats the boiler of a effect. But in the animal body we recogsteam engine we can produce every kind nise as the ultimate cause of all force only of motion, and by certain amount of motion one cause, the chemical action which the we can produce fire. elements of the food and the oxygen of the When we rub a piece of sugar briskly on air mutually exercises on each other. The an iron grater, it undergoes, at the surfaces only known ultimate cause of vital force, of contact, the same change as if exposed either in animals or in plants, is a chemical to heat; and two pieces of ice, when rubbed process. If this be prevented, the phenotogether, melt at the point of contact. mena of life do not manifest themselves, or Let us remember that the most distin- they cease to be recognisable by our senses. guished authorities in physics consider the If the chemical action be impeded, the vital phenomena of heat as phendmena of motion, phenomena must take new forms. because the very conception of the creation According to the experiments of Despretz, of matter, even though imponderable, is ab- 1 oz. of carbon evolves, during its combussolutely irreconcilable with its production tion, as much heat as would raise the temby mechanical causes, such as friction or perature of 105 oz. of water at 320 to 1670, motion. that is, by 135 degrees; in all, therefore, But, admitting all the influence which 105 times 1350= —14207 degrees of heat. electric or magnetic disturbances in the ani- Consequently, the 1'39 oz. of carbon which real body can have on the functions of its are daily converted into carbonic acid in the organs, still the ultimate cause of all these body of an adult, evolve.139X142070o forces is a change of condition in material 197477-3 degrees of heat. This amount of particles, which may be expressed by the heat is sufficient to raise'the'temperature ot conversion, within a certain time, of the ele- 1 oz. of water by- that number of degrees, ments of the food into oxidised products. or from 320 to 1975093;30 or- to cause Such of these elements as do not undergo 136'8 lbs. of water at 320 to boil; or to this process of slow combustion, are given' heat 370 lbs. of water to 98'30 (the temoff unburned or incombustible in the exe- perature of the human body;) or to convert crements. into vapour 24 lbs. of water at 98'30. Now, it is absolutely impossible that a If we now assume that the quantity of given amount of carbon or hydrogen, what- water vaporized through the skin and lungs ever different forms they mnay assume in the in 24 hours amounts to 48 oz. (3 lbs.,) then progress of the combustion, can produce there will remain, after deducting the necesmore heat than if'directly burned into atmos- sary amount of heat, 146380-4 degrees of pheric air or in oxygen gas. heat, which are dissipated by radiation, by When we kindle a fire under a steam heating the expired air, and in the excreengine, and employ the power obtained to mentitious matters. produce heat by friction, it is impossible In this calculation, no account has been that the heat thus obtained can ever be taken of the heat evolved by the hydrogen greater than that which was required to of the food, during its conversion into Water heat the boiler; and if we use the galvanic by oxidation within the body. But if we current to produce heat, the amount of heat consider that the specific heat of the bones, obtained is never in any circumstances, of fat, and of the organs generally, is far greater than we might have by the com- less than that of water, and that consebustion of the zinc which has been dissolved quently they require, in order to be heated in the acid. _ to 98.30, much less heat than an equal The contraction of muscles produces heat; weight of water, no doubt can be enterbut the force necessary for the contraction tained, that when all the concomitant cirhas manifested itself through the organs of cumstances are included in the calculation, motion, in which it has been excited by the heat evolved in the process of combuschemical changes. The ultimate cause of tion, to which the food is subjected in the the heat produced is, therefore, to be found in body, is iamply sufficient to explain the conthese chemical changes. stant temperature of the body, as well as By dissolving a metal in an acid, we the evaporation from the skin and lungs. produce an electrical current; this current, VI. All experiments hitherto made on the if passed through a wire, converts the wire quantity of oxygen which an animal conint, a magnet, by means of which, many sumes in a given time, and also the concrh 2v ANIMAL CHEMISTRY. sions deduced from them as the origin of obvious. They appear naturally both in animal heat, are destitute of practical value man and animals at certain seasons of the in regard to this question, since we have year, and we say in such cases that we are seen that the quantity of oxygen consumed freezing, or experience the sensation of cold. varies according to the temperature and It is plain, that if we were to clothe a man'density of the air, according to the degree in a metallic dress, and tie up his hands and of motion, labour, or exercise, to the amount feet, the loss of heat, for the same consumpand quality of food, to the comparative tion of oxygen, wouldbe far greater than warmth of the clothing, and also according if we were to wrap him up in fur'and to the time within which the food is'taken, woollen cloth. Nay, in the latter case, we Prisoners in the Bridewell at Marienschloss should see him begin to perspire, and warm (a prison where labour is enforced,) do not water would exude, in drops, through the consume more than 10'5 oz. of carbon daily; finest pores of his skin. those in the House of Arrest at Giessen, If to these considerations we add, that dewho are deprived of all exercise, consume cisive experiments are on record, in which only 8'5 oz.; (6) and in a family well known animals were made to respire in an unnato me, consisting of nine individuals, five tural position, as for example, lying on the adults, and four children of different ages, back, with the limbs tied so as to preclude the average daily consumption of carbon for motion, and that the temperature of their each, is not more than 9'5 oz. of carbon.? bodies was found to sink in a degree appreWe may safely assume, as an approxima- ciable by the thermometer, we can hardly tion, that the quantities of oxygen consumed be at a loss what value we ought to attach in these different cases are in the ratio of to the conclusions drawn from such experithese numbers; but where the food contains ments'as those above described. meat, fat, and wine, the proportions are These experiments and the conclusions altered by reason of the hydrogen in these deduced from them, in short, are incapable kinds of food which is oxidised, and which, of furnishing the smallest support to the in being converted into water, evolves much opinion that there exists, in the animal body, more heat for equal weights. any other unknown source of heat, besides The attempts to ascertain the amount of the mutual chemical action between the eleheat evolved in an animal for a given con- ments of the food and the oxygen of the air. sumplion of oxygen have been equally The existence of the latter cannot be doubted unsatisfactory. Animals have been allowed or denied, and it is amply sufficient to exto respire in close chambers surrounded plain all the phenomena. with cold water; the increase of tempera- VII. If we designate the production of ture in the water has been measured'by the force, the phenomena of motion in the anithermometer, and the quantity of oxygen mal body as nervous life, and the resistance, consumed has been calculated from the the condition of static equilibrium, as vegeanalysis of the air before and after the ex- tative life; it is obvious that in all classes periment. In experiments thus conducted, of animals the latter, namely, vegetative life, it has been found that the animal lost about prevails over the former, nervous life, in the,I more heat than corresponded to the earlier stages of existence. oxygen consumed; and had the windpipe The passage or change of matter from a of the animal been tied, the strange result state of motion to a state of rest'appears in would have been obtained of a rise in the an increase of the mass, and in the supply temperature of the water without any con- of waste; while the motion itself, or the sumption of oxygen.' The animal was at the production of force, appears in the shape of temperature of 980 or 990, and the water, waste of matter. in the experiments of Despretz, was at In a young animal, the waste is less than 47'50. Such experiments consequently the increase; and the female retains, up to prove, that when a great difference exists a certain age, this peculiar condition of a between the temperature of the animal body more intense vegetative life. This condition and that of the surrounding medium, and does not cease in the female as in the male, when no motion is allowed, more heat is with the complete development of all the given off than corresponds to the oxygen organs of the body. consumed. In equal times, with free and The female in the lower animals, is, at unimpeded motion, a much larger quantity certain seasons, capable of reproduction of of oxygen would be crnsumed without a the species.'The vegetative life in her orperceptible increase ir -.he amount of heat ganism is rendered more intense by certain lost. The cause of these phenomena is external conditions, such as temperature, food, &c.; the organism produces more than * In this family, the monthly consumption was is w asted, and" the result is the capacity of 151 lbs. of brown bread, 70 lbs. white bread, 132 reproduction. lbs. meat, 19 lbs. sugar, 15'9 lbs. butter, 57 maass In the human species, the female organism (about 24 gallons) of milk; the carbon of the po- is independent of those external causes tatoes and other vegetables, of the poultry, game, which increase the intensity of vegetative and wine consumed, having been reckoned as equal to that contained in the exerementitious life. When the organism is fullydeveloped, matters, the carbon of the above articles was con- it is at all times capable of reproduction of sidered as being converted into carbonic acid. the species; and infinite wisdom has givei FIBRINE AND ALBUMEN. 21.o the female body the power, up to a certain bodies in small quantity, which differ from age, of producing all parts of its organization ordinary fats in several of their properties. in greater quantity than is required to sup- Chemical analysis has led to the remarkply the daily waste. able result, that fibrine and albumen contain This excess of production can be shown the same organic elements united in the to contain all the elements of a new organism, same proportion, so that two analyses, the it is constantly accumulating, and is periodi- one of fibrine and the other of albumen, do cally expelled from the body, until it is ex- not differ more than two analyses of fibrine pended in reproduction. This periodical or two of albumen respectively do, in the discharge ceases when the ovum has been composition of 100 parts. impregnated, and from this time every drop In these two ingredients of blood the parof the superabundant blood goes to produce ticles are arranged in a different order, as is an organism like that of the mother. shown by the difference of their external Exercise and labour cause a diminution properties; but in chemical composition, in in the quantity of the menstrual discharge; the ultimate proportion of the organic eleand when it is suppressed in consequence ments, they are identical. of disease, the vegetative life is manifested This conclusion has lately been beautifully in a moirbid production of fat. When the confirmed by a distinguished physiologist equilibrium between the vegetative and ner- (Denis,) who has succeeded in converting vous life is disturbed in the male, when, as fibrine into albumen, that is, in giving it the in eunuchs, the intensity of the latter is di- solubility, and coagulability by heat, which minished, the predominance of the former characterize the white of egg. is shown in the same form, in an increased Fibrine and albumen, besides having the deposit of fat. same composition, agree also in this, that VIII. If we hold, that increase of mass in both dissolve in concentrated mariatic acid, the animal body, the development of its or- yielding a solution of an intense purple gans, and the supply of waste,-that all this colour. This solution, whether made with is dependent on the blood, that is, on the fibrine or albumen, has the very same reingredients of the blood, then only those actions with all substances yet tried. substances can properly be called nutritious,. Both albumen and fibrine, in the process or considered as food which are capable of of nutrition, are capable of being converted conversion into blood. To determine, there- into muscular fibre, and muscular fibre is fore, what substances are capable of afford- capable of being reconverted into blood. ing nourishment, it is only necessary to as- These facts have long been established by certain the composition of the food, and to physiologists, and chemistry has merely compare it with that of the ingredients of proved that these metamorphoses can be the blood. accomplished under the influence of a cerTwo substances require especial conside- tain force, without the aid of a third subration as the chief ingredients of the blood; stance, or of its elements, and without the one of these separates immediately from the addition of any foreign element, or the sepablood when withdrawn from the circulation. ration of any element previously present in It is well known that in this case blood these substances. coagulates, and separates into a yellowish If we now compare the composition of all liquid, the seroum of the blood, and a gela- organized parts with that of fibrine and albutinous mass, which adheres to a rod or stick men, the following relations present themin soft, elastic fibres, when coagulating blood selves: is briskly stirred. This is thefibrine of the All parts of the animal body which have blood, which is identical in all its properties a decided shape, which forms parts of orwith muscular fibre, when the latter is pu- gans, contain nitrogen.'No partof an organ rified from all foreign matters.. which possesses motion and life is destitute The second principal ingredient of the of nitrogen; all of them contain likewise blood is contained in the serum, and gives carbon and the elements of water, the latter, to this liquid all the properties of the white however, in no case in the proportion to of eggs, with which it is identical. When form water. heated, it coagulates into a white- elastic The chief ingredients of the blood contain mass, and the coagulating substance is nearly 17 per cent. of nitrogen, and no part called albumen. of an organ contains less than 17 per cent. Fibrine and albumen, the chief ingredients of nitrogen. (7) of blood, contain, in all, seven chemical The most convincing experiments and elements, among which nitrogen, phos- observations have proved that the animal phrus, and sulphur are found. They con- body is absolutely incapable of producing tain also the earth of bones. The serum an elementary body, such as carbon or niretains in solution sea salt and other salts trogen, out of substances which do not conof potash and soda, in which the acids are tain it; and it obviously follows, that all carbonic, phosphoric, and sulphuric acids. kinds of food fit for the production either of The globules of the blood contain fibrine and blood, or of cellular tissue, membranes, skin, albumen, along with a red colouring matter, hair, muscular fibre, &c., must contain a in which iron is a1 constant element. Be- certain amount of nitrogen, because that side these, the blood contains certain fatty element is essential to the composition of 522 A N ANIMAL CHEMISTRY. the above named organs; because the or- what are commonly called vegetables. They gans cannot create it from the other elements exist, howeve.r, in all plants, without exceppresented to them; and, finally, because no tion, and in every part of plants in larger or nitrogen is absorbed from the atmosphere in smaller quantity. the vital process. These nitrogenizea forms of nutriment in The substance of the brain and nerves the vegetable kingdom may be reduced to contains a large quantity of albumen, and, three substances, which are easily distin. in addition to this, two peculiar fatty acids, guished by their external characters. Two distinguished from other fats by containing of them are soluble in water, the third is phosphorus (phosphoric acid?) One -of insoluble. these contains nitrogen (Fr6my.) When the newly expressed juices of Finally, water and common fat are those vegetables are allowed to stand, a separation ingredients of the body which are destitute takes place in a few minutes. A gelatinous of nitrogen. Both are amorphus or unor- precipitate, commonly of a green tinge, is ganized, and only so far take part in the deposited, and this, when acted on by liquids vital process as that their presence is re- which remove the colouring matter, leaves quired for the due performance of the vital a grayish white subtance, well known to functions. The inorganic constituents of druggists as the deposit from vegetablejuices. the body are, iron, lime, magnesia, common This is one of the nitrogenized compounds salt, and the alkalies. which serves for the nutrition of animals, IX. The, nutritive process in the carni- and'has been named vegeetablefibrine. The vora is seen in its simplest form. This class juice of grapes is especially rich in this of animals lives on the blood and flesh of constituent, but it is most abundant in the the graminivora; but this blood and flesh seeds of wheat, and of the cerealia. It may is, in all its properties, identical with their be obtained from wheat flour by a mechaniown. Neither chemical nor physiological cal operation, and in a state of tolerable differences can be discovered. purity; it is then called gluten, but the glutinThe nutriment of carnivorous animals is ous property belongs, not to vegetable fibrine, derived originally from blood; in their sto- but to a foreign substance, present in small mach it becomes dissolved, and capable of quantity, which is not found in the other reaching all other parts of the body; in its cerealia. passage it is again converted into blood, The method by which it is obtained suffiand from this blood are reproduced all ciently proves that it is insoluble in water; those parts of their organization which have although we cannot doubt that it was origiundergone change or metamorphosis. nally dissolved in the vegetable juice, frorn With the exception of hoofs, hair, fea- which it afterwards separated, exactly as ANIMAL CtHEMISTRY. Or — 5 (C48N6H39015) + 045 C240N30H1950120 - 6 atoms benzoic acid, 6 (C14 H5 03)= CS4 H30018 12712 atoms urea. 27 (C NH2 0 ) = C27 N27HS4027 _ — 3 atoms choleic acid 3 (C38NH3301') = C"4N3 H99033 15 atoms carbonic acid 15 (C 02 ) C15 0O0 12, atoms water.. 12 ( H 0 ) = H12012 The sum is...... C2N30H950120 35. Lastly, let us follow the metamor- will appear that 2 at. of proteine without phosis of the tissues in the fcetal calf, con- the addition of oxygen or any other foreign sidering the proteine furnished in the blood element, except 2 at. of water, contain the of the mother as the substance which under- elements of 6 at. of allantoine and 1 at. of goes or has undergone a transformation; it choloidic acid (meconium?) 2 atoms proteine = 2 (C48N6H360'4) -- 2 atoms water = 2HO =- C96N12H74030 S 6 atoms allantoine, 6 (C4N2H303) = C24N12HI'80' - 1 atom choloidic acid = C72 HO56012 * C96N12H740o0 36. But the elements of the six atoms of I exactly to the elements of 2 at. of uric acid, allantoine in the last equation correspond.2 at. of urea, and 2 at. of water. (2 atoms uric acid C20N8H80'2 6 atoms of allantoine = C24N'2HI15018 = - 2 atoms urea C4 N4H804 2 atoms water H202 ~*~~'' + C N12Hl8018 The relations of allantoine, which is found transformation of the compounds of protelne. in the urine of the fcetal calf, to the nitro- 37. Further, if to the formula of proteine, genized constituents of the urine in animals multiplied by 3, we add the elements of 4 which respire, are, as may be seen by corn- at. of water,. and if we deduct from the sum paring the above formulae, such as cannot of all the elements half of the elements of Dbeoverlooked or doubted. Allantoine con- choloidic acid, there remains a formula tains the elements of uric acid and urea- which expresses very nearly the composithat is, of the nitrogenized products of the tion of.gelatine. From 3 (C48N6H36014) + 4 HO. -C144N18H112046 Subtract i atom choloidic acid = Cm H2s 06 There remain..... C'08N'8H84040 (35) 38. Subtracting from this formula of gela- water, or of 3 at. of allantoine and 3 at. of tine the elements of 2 at. of proteine, there water. Thusremain the elements of urea,. uric acid, and Formula of gelatine (Mulder) Cl10SN18H84040 Subtract 2 atoms proteine. C96 N12H72028 There remain... C' N6 T112012 51 atom uric acid C'~N4H406 atom ureaic.cid CN2H402 -o $3 atoms allantoine CT2N6H909 j4 atoms water H4. H3 C'2N H'2012 C12N6H'20'2 39. The numerical proportions calculated more importance than justly belongs to from the above formula differ from those them. I would constantly remind the reader actually obtained in the analyses of Mulder that their use is to serve as points of conand Sherer in this, that the latter indicate nexion, which may enable us to acquire somewhat less of nitrogen in gelatine; but more accurate views as to the production if we assume the formpla to be correct, it and decomposition of those compounds then appears, from the statement just given, which form the animal tissues. They are that the elements of two atoms of proteine, the first attempts to discover the path which plus the nitrogenized products of the trans- we must follow in order to attain the object formation of a third atom of proteine (uric of our researches; and this object, the goal acid and urea) and water; or three atoms we strive to reach, is, and must be, atof proteine, minus the elements of a corn- tainable. pound containing no nitrogen, which ac- The experience of all those who have octually occurs as one of the products of the cupied themselves with researches into natransformation of choleic acid, yield in both tural phenomena leads to this general result, cases a formula closely approaching to the that these phenomena are caused or procomposition of gelatinous tissues. We must, duced, by means far more simple than those however, attach to such formulae, and to previously supposed, or than we even now the considerations arising from them, no imagine; and it-is precisely their simplicity ORIGIN OF THE BILE. 47 which should most powerfully excite our ing the passage of the chyme through the wonder and admiration. intestinal canal. take the form of albunien, Gelatinous tissue is formed from blood, which, as the results of incubation in the from compounds of proteine. It may be fowl's egg testify, contains the fundamental produced by the addition, to the elements of elements of all organized tissues, with the proteine, of allantoine and water, or of wa- exception of iron, which is obtained from ter, urea, and uric acid; or by the separation other sources. from the elements of proteine of a com- Practical medicine has long ago answered pound containing no nitrogen. The solution the question, what becomes in man of the of such problems becomes less difficult, compounds of proteine taken in excess, when the problem to be solved, the question what change is undergone by the superato be answered, is matured'and clearly put. bundan't nitrogenized food? The blood-vesEvery experimental decision' of any such sels are distended with excess of blood, the question in the negative' forms the starting- other vessels with excess of their fluids, and point of a new question, the solution of if the too great supply of food be kept up, which, when obtained, is the necessary and the blood, or other fluids adapted for consequence of our having put the first forming blood, be not applied to their natuquestion. - ral purposes, if the soluble matters be not 40. In the foregoing sections,. no other taken up by the proper organs, various gases constituent of the bile, besides choleic acid, are disengaged, as in processes of putrefachas been brought into. the calculation; be- faction, the excrements assume an altered cause it alone is known with certainty to quality in colour, smell, &c. Should the contain nitrogen. Now, if it be admitted fluids in the absorbent and lymphatic ves that its nitrogen is derived from the meta- sels undergo a similar decomposition, this is morphosed tissues, it is not improbable that immediately visible in the blood, and the the carbon, and other elements which it con- nutritive process then assumes new forms. tains, are derived from the same source. 42. No one of all these appearances should There cannot be the smallest doubt, that occur, if the liver and kidneys were capable in the carnivora, the constituents of the of effecting the resolution of the superabunurine and the bile are derived from the trans- dant compounds of proteine into urea, uric formation of compounds of proteine; for, acid, and bile. All the observations which except fat, they consume no food but such have been made in reference to the influence as contains proteine, or has been formed of nitrogenized food on the composition of from that substance. Their food is identical the urine have failed entirely to demonstrate with their blood; and it is a matter of in- the existence of any direct influence of the difference which of the two we select as the kind; for She phenomena are susceptible of starting-point of the chemical developement another and a far more simple interpretation, of the vital metamorphoses. if, along with the food, we consider the -There can be no greater contradiction, mode of life and habits of the individuals with regard to the nutritive process, than to who have been the subjects of investigation. suppose that the nitrogen of the food can Gravel and calculus occur in persons who pass into the urine as urea, without having use very little animal food. Concretions of previously become part of an organized tis- uric acid have never yet been observed in sue; for albumen, the only constituent of carnivorous mammalia, living in the wild blood,, which, from its amount, ought to be stated and among nations which live entirely taken into consideration- suffers not the on flesh, deposits of uric acid concretions in slightest change in passing through the livei the limbs or in the bladder are utterly unor kidneys; we find it in every part of the known. body with the same appearance and the 43. That which must be -viewed as an same properties. These organs cannot be undeniable truth in regard to the origin of adapted for the alteration or decomposition the bile, or, more accurately speaking, of of the substance from which all the other choleic acid in the carnivora, cannot hold in organs-of the body are to be formed. regard to all the constituents of the bile se41. From the characters of chyle and'creted by the liver in the herbivora, for with lymph, it appears with certainty that the the enormous quantity of bile produced, for soluble parts of the food or of the chyme example, by the liver of an ox, it is absoacquire the form of albumen. Hard-boiled lutely impossible to suppose that all its carwhite of egg, boiled or coagulated fibrine, bon is'derived from the metamorphosed which have again become soluble in the tissues. stomach, but have lost their coagulability by Assuming the 59 oz. of dry bile (from 37 the action of air or heat, recover these pro- lbs. of fresh bile secreted by an ox) to conperties by degrees. In the chyle, the acid tain the same per centage of nitrogen as choreaction of the chyme has already passed leic acid, (3-86 per cent.,) this would amount into the weak alkaline reaction of the blood; to nearly 21 oz. of nitrogen; and if this niand the chyle, when, after passing through the mesenteric glands, it has reached the thoracic duct, contains albumectn coacrulable by k* The occurrence of urate of ammonia in X conracic duct, co ntains albumen cretion found in a dog, which was examined by heat; and, when left to itself, deposits fibrine. Lassaigne, is to be doubted, unless Lassaigne cxAll the compounds of proteine, absorbed dur- tracted it himself from the bladder of the animal, 48 ANIMAL CHEMISTRY. trogen proceed from metamorphosed tissues, mere idle play with formule, and not to then, if all the carbon of these tissues passed lose sight of our chief object, we observe, into the bile, it would yield, at the utmost, therefore, that the consideration of the a quantity of bile corresponding to 7-15 oz. quantitative proportion of the bile secreted of carbon. This is, however, far below the in the herbivora leads to the following con-quantity which, according to observation, is clusions:secreted in this class of animals. The chief constituents of the bile of the 44. Other substances, besides compounds herbivora contain nitrogen, and this nitrogen of proteine, must inevitably take part in the is derived from compounds of proteine. formation of bile in the organism of the The bile of this class of animals contains herbivora; and these substances can only be more carbon than corresponds to the quanthe non-nitrogenized constituents of their tity of nitrogenized food taken, or to the porfood. tion of tissue that has undergone metamor45. The sugar of bile of Gmelin (picromel phosis in the vital process. or biline of TBerzelius,) which Berzelius con- A part of this carbon must, therefore, be siders as the chief constituent of bile, while derived from the non-nitrogenized parts of Demarqay assigns that place essentially to the food (starch, sugar, &c.;) and in order choleic acid, burns, when heated in the air; to be converted into a nitrogenized constilike resin, yields ammoniacal products, and tuent of bile, a part of the elements of these when treated with acids, yields taurine and bodies must necessarily have combined with the products of the decomposition of choleic a nitrogenized compound derived from a acid; when acted on by alkalies, it yields compound of proteine. ammonia and cholic acid. At all events, In reference to this conclusion, it is quite the sugar of bile contains nitrogen, and much indifferent'whether that compound of proless oxygen than starch or sugar, but more teine be derived from the food or from the oxygen than the oily acids. When, in the tissues of the body. metamorphosis of sugar of bile or choleic 48. It has very lately been stated by A. acid by alkalies, we cause the separation Ure, that benzoic acid, when administered of nitrogen, we obtain a crystallized acid, internally, appears in the urine in the form very similar to the oily acids (cholic acid,) of hippuric acid. and capable of forming with bases salts, Should this observation be confirmed,' it which have the general characters of soaps. will acquire great physiological significance, Nay, we may even consider the chief con- since it would plainly prove that the act of stituents of the bile,'sugar of bile and cho. transformation of the tissues in the animal: leic acid, as compounds of oily acids with body, under the influence of certain matters organic oxides, like the fat oils, and only taken in the food, assumes a new form with differing from these in containing no oxide respect to the products which are its result; of glycerule. Choleic acid, for example, for hippuric acid contains the elements of may be viewed as a compound of choloidic lactate of urea, with the addition of those acid with allantoine and water:'of benzoic acid: Choloid. acid. Allant. Water. Choleic acid. 1 at. urea. C2N2H4 02) C72EIH56012C4N2H3O3+H70=7-C76N2H660O2 1 at. lactic acid. C6 H4 04 Or as a compound of cholic acid, urea, 2 at. benzoic acid. C H'006 and water: C35N2Hs012*Cholic acid. Urea. Water. Choleic acid. C74H60018+C2N2H402_+}H2O2C76N2H66 O - 52 at. chrystallized hippuric 46. If, in point of fact, as can hardly be - acid = 2 (C'SNH906) doubted, the elements of such substances as 49. If we consider the act of transformastarch, sugar, &c., take part in the produc- tion of the tissues in the herbivora as we tion of bile in the organism of the herbivora, have done in the carnivora,' then the blood there is nothing opposed to such a view in of the former must yield, as the last products the composition of the chief constituents of the metamorphosis, from all the organs of bile, as far as our knowledge at present taken together, choleic acid, uric acid, and extends. ammonia (see p. 44;) and if we ascribe to the If starch be the chief agent in this pro- uric acid an action similar to that of the cess, it can happen in no other way but benzoic acid in Ulre's observation-such, this-that, as when it passes into fat, a cer- namely, that the further transformation, tain quantity of oxygen is separated from owing to the presence of this acid, assumes the elements of the starch, which, for the another form, the elements of the uric acid same amount of carbon, (for 72 atoms,) con- being incorporated in the final products —it tains five times as much oxygen as choloidic will appear, for example, that 2 at. of prodcid. Without the separation of oxygen from the elements of starch, it is impossible to * The analysis of the crystals deposited from monceive its conversion into bile; and this the urine on the addition of muriatic acid has not separation being admitted, its conversion been perfbrmed. Besides, the statement of A. into a compound intermediate in composition Ure, that hippuric acid, dissolved in nitric acid, is reddened by ammonia, is erroneous, and shows between starch and fat offers no difficulty. that the crystals he obtained must have contained 47. Not to render these consideratlors a uric acid. SECRETIONS AND EXCRETIONS. 49 teme, with the addition of the elements of i give rise to the production of hippuric acid 3 at. of uric acid and 2 at. of oxygen, might I and urea. 2 at. proteine, 2 (C48N6H36014) _ C96N12H72028 3 at. uric acid, 3 (C'0N4 H406 ) C30Nl2HI2018 2 at. oxygen - O2 The sum is. C126N24Hs4048s 6 at. hippuric acid, 6 (C18N H805) C108N6 H48030 9 at- urea. 9 (C2 N2'H402) C18 NlSH36018 The sum is.... l6N24HS4048 50. Finally, if we bear in mind, that, in duce the nitrogenized constituents of the the herbivora, the non-nitrogenized con- bile, the most striking result of the combinastituents of their food (starchi, &c.) must, as tions'thus suggested is this, that the elements we have shown, play an essential part in of starch added to those of hippuric acid are the formation of the bile; that to their ele- equal to the elements of choleic acid, plus, ments must of necessity be added those of a certain quantity of carbonic acid: a nitrogenized compound, in order to pro2 at. hippuric acid, 2 (C8sNHs 05) - C36N2H'6010 5 at. starch.. 5 (C12 H10010) = 60 H50050 2 at. oxygen.. = 02 The sum is.. - CC9GN2H66062 _ 2 at. choleic acid 2 (C3sNlI330"t) - 016N2H66022 20 at. carbonic acid 20 (C 2 ) C0 040 The sum is ~...., C H66062 51. Now since hippuric acid may be de- tion occurs, and during the further transforrived, along with urea, from the compounds mation, the elements of starch be present of proteine, when to the elenments of the and enter into the new products, we shall latter are'added those of uric acid (see p. obtain an additional quantity of choleic acid, 49;) since, further, uric acid, choleic acid, as well as a certain amount of carbonic and ammonia contain the elements of pro- acid gas. teine in a proportion almost identical with That is to say-that if the elements of that of proteine itself (see p. 44;) it is proteine and starch, oxygen andwater being obvious that, if from 5 at. of proteine, with also present, undergo transformation together the addition of oxygen and of the elements and mntually affect each other, we obtain, of water, there be removed the elements of as the product of this mnetamorphosis, urea, choleic acid and ammonia, the remainder choleic acid, ammonia, and carbonic acid, will represent the elements of hippuric acid and besides these, no other product whatever. and of urea; and that if, when this separa- The elements of 5 at. proteine 9 at. choleic acid 15 at. starch 9 at. urea 12 at. water 6 3 at. ammonia 5 at. oxygenJ 60 at. carbonic acid In detaill 5 at. proteine, 5 (C4sN6H3O14) - C240N3OH180070 15 at. starch, 15 (C12 H100'0) - C180 H500150 12 at. water, 12 ( HO ) H' 2 012 5 at. oxygen O5 The sum is... C40~N30H342023and9 at. choleic acid, 9 (C3s8NT130l1) C342N~HI97099 9 at. urea,... 9 (C2 N2H4 02) C'SN1SH36 0s18 3 at. ammonia,. 3( N H3 ) N3H9 60 at. carbonic acid, 60.(0 Q2) -60 0120 The sum is...... C420N30H342023 The transformation of the compounds of creted by the kidneys, and choleic acid, sel)oteine present in the body is effected by creted by the liver. means of the oxygen conveyed by the arte- Nothing, therefore, in the chemical comrnrial blood, and if the elements of starch, position of those matters which may be rendered soluble in the stomach, and thus supposed to take a share in these metamorcarried to every part, enter into the newly phoses, is opposed to the supposition that a formed compounds, we have the chief con- part of the carbon of the non-azotized food stituents of the animal secretions and ex- enters into the composition of the bile. cretions; carbonic acid, the excretion of the 52. Fat, in the animal body,'disappears lungs, urea and carbonate of ammonia, ex- when the supply of oxygen is abundant. 7 E 0 AN-IM AL CHEMISTRY. When that supply is deficient, choleic acid acid is known to be the chief constituent of may be converted into hippuric acid, litho- the bezoar stones, which occur in certain fellic acid, (37) and water. Lithofellic I herbivorous animals: 2at. choleic acid C76N216 022 - 2 at. hip. acid C36N2H16010 2 at. choleic acid C76NH6I'2}-= I at. lith. acid C40 H3608 10 at. oxygen 010 14 at. water. 14014 C76N2H66032 C76N2H66032 53. For the production of bile in the. proteine can yvield only fat and urea. If we animal body a certain quantity of soda is, suppose fat to be composed according to in all circumstances, necessary; without the the empirical formula C1IH'00, then, by the presence of a compound of sodium- no bile addition of oxygen and the elements of can be formed. In the absence of soda, the water, to the elements of proteine, we have metamorposis of the tissues composed of the elements of fat, urea, and carbonic acid Proteine. Water. Oxygen. 2 (C48N6H36014) 4+ 12 HO + 14 0 C96N12H84054 6 at. urea... C12N2H24 -< Fat.... C66 H6006 C18 at. carbonic acid = C8 036 C96NI2HS4064, The composition of all fats lies between - 1 at. uric acid C10N4H4 06 ) the empirical formulae CI'Hl~O and C12ilOO. 1 at. urea... C2 N2H4 02O = If we adopt the latter, then the elements of 22 at. water.. H22022) 2 at. proteine, with the addition of 2 at. C12N63o003o0 oxygen and 12 at. water, will yield 6 at. urea, fat (C72H6006), and 12 at. carbonic acid. 3 at. taurine C12N3H2 030 It is worthy of observation, in reference 3 at. ammonia N3H9 to the production of fat, that the absence of C12N6HO0030 common salt (a compound of sodium which llntoine C4N2H303 furnishes soda to the animal organism) 1 at. allantoine CNH0 is favorable to the formation of fat; that the at water.. H0 fattening of an animal is rendered impossi- C4NiH~0s~o ble, when we add to its food an excess of C 1 at. taurine C4N H salt, although short of the quantity required to produce a purgative effect. C4N2H-00 54. As a kind of general' view of the metamorphoses of the nitrogenized animal 55. In reference to the metamorphoses of secretions, attention may here be very pro- uric acid of the products of the transformaperly directed to the fact, that the nitrogen- tion of the bile, it is not less significant, and ized products of the transformation of the worthy of remark, that the addition of oxybile are identical in ultimate composition gen and the elements of water to the elewith the constituents of the urine, if to the ments of uric acid may yield either taurine latter be added a certain proportion of the and urea, or taurine, carbonic acid, and am elements of water. monia. 1 at. uric acid CN4H4 06 at tarine 2 t- 2 at. taurine CSN 2H'402~ 14 at. water. H. 1 H4Oi4 2 14at. 2ure C2N2H402' 1 at. urea. C2N2H40 2 at. oxygen 02 - C 10Ni4H1802 C10N4H08022. (2 at. taurine: CsN2H'4020 1 2 at. carbonic acid C2 04 Add 2 at. water H2 02 J 2 at. ammonia N2H6 Ci0N4H20024 C10N4H20024 56. Alloxan, plus a certain amount of tains the elements of super-oxalate of amwater, is identical in the proportion of ele- monia. ments with taurine; and finally, taurine conl1at. alloxan* CsN2H4 0~ Tarn 10 at. water H~0~ } (2 C4NH7O0O) (2 at. oxalic acid C4 06 1 at. taurine C4NH7010=- 1 at. ammonia NHS (4 at. water.. H404 C4NH7010 * It would be mcst interesting to investigate Ia large dose appeared to act only on the kidneys. the action of alloxan on the human body. Two In certain diseases of the liver, alloxan would or three drachms, in crystals, had no injurious very probably be found a most powerful remedy. action on rabbi~ to which it was given. In man, -J. L. RELATION OF STARCH TO BILE. 51 57. The comparison of the amount of are in such proportion, that ly the addition carbon in th'e bile secreted by an herbivorous of the elements of water, all its carbon is animal, with the quantity of carbon of its converted into carbonic acid, and all its nitissues, or of the nitrogenized constituents trogen into ammonia. of its food, which in consequence of the I at. urea C2N2H402 constant transformations may pass into bile, indicates, as we have just seen, a great difference.2N2H604 The carbon of the bile secreted amounts, at least, to more than five times the quantity 2 at. amrbonic acid... 04 of that which could reach the liver in con- { 2 at. carbonic acid C2 sequence of-the change of matter in the body, either from the metamorphosed tissues or from the nitrogenized constituents of the 61. Were we able directly to produce food; and we may' regard as well founded taurine and ammonia out of uric acid or althe supposition that the non-azotized con- lantoine, this might perhaps be considered stituents of the food take a decided share in as an additional proof of the share which the production of bile in the herbivora; for has' been. ascribed to these compounds in neither experience nor observation contra- the production of bile; it cannot, however, dicts this opinion. be viewed as any objection to the views 58. We have given, in the foregoing para- above developed on the subject, that, with graphs, the analytical proof, that the nitro- the means we possess, we have not yet suegenized products of the transformation of ceeded in effecting these transformations out bile, namely, taurine and ammonia, may be of the body. Such an objection loses all its formed from all the constituents of the urine, force,. when we -consider that we cannot with the exception of urea-that is, from admit, as proved, the pre-existence of tauhippuric acid, uric acid,allantoine; and when rine and ammonia in the bile; nay, that it we bear in mind that, by the mere separation is not even probable that these compounds, of oxygen and the elements of water, cho- which are only known to us as products of loidic acid may be formed from starch;- the decomposition of the bile, exist ready From 6 at. starch=(C12H10010)=C72I 60060 formed. as ingredients of.that fluid. Subtract 44 at. oxygene - H4048~ By the action of muriatic acid on bile, 4 at. water -' - Ar we, in a manner, force its elements to anite Reains choloidic acid -Cin such forms as are no longer caparle of emains choloidi acid.. 7 change under the influence of the same rethat, finally,.choloidic acid, ammonia, and agent; and when, instead of the acid, we taurine, if added together, contain the ele- use potash, we obtain the same elements, ments of choleic acid; — although arranged in another, and'quite a at. choloidic acid= Cdifferent manner. If taurine were present,. at. choloidic acid --- c7'- H1~Ow' 1 at. taurine...-C N H7 1Oil:ready formed, inl bile, we should obtain the 1 at.' ammonia.. N H3 - same products by the action of acids and of 1 at'. choleic acid - CGU76N1660e22 alkalies. This, however, is contrary to ex[ at. choleic acid - C76N 2Hf66022;- perience. if all this be considered, every doubt as to Thus, even if we could convert allantoine, the possibility of these changes is removed. or uric acid and urea, into taurine and am59. Chemical analysis and the study of monia, out of the body, we'should acquire the living animal body mutually support no additional insight into the true theory of each other; and both lead to the conclusion the formation of bile, just because the prethat a certain portion of the carbon of the non- existence of ammonia and taurine in the azotized constituents of food (of starch, &c., bile must be doubted, and because we have the elements of respiration) is secreted by no reason to believe that urea or allantoine, the liver in the form of bile; and further, as such, are employed by the organism in that the nitrogenized products of the trans- the production of bile. We can prove that formation of tissues in the herbivora do not, their elements serve this purpose, but we as in the carnivora, reach the kidneys imme- are utterly ignorant'how these elements diately or directly, but that, before their ex- enter into these combinations, or what is pulsion from the body in the form of urine, the chemical character of the nitrogenized they take a share in certain other processes, compound which unites with the elements especially in the formation of the bile. of starch to form bile, or rather choleic acid. They are conveyed to the liver with the 62. Choleic acid may be formed from non-azotized constituents of the food; they the elements of starch with those of uric are returned to the circulation in the form acid and urea, or of allantoine,'or of uric of bile, and are not expelled by the kidneys, acid, or of alloxan, or of oxalic acid and till they have thus served for the production- ammonia, or of hippuric acid. The possiof the most important of the substances em- bility of its being produced from so great a ployed in respiration. variety of nitrogenized compounds is suffi60. When the urine is left to itself, the cient' to show that all the nitrogenized prourea which it contains is converted into car- ducts of the metamorphosis of the tissues bonate of ammonia; the elements of urea may be employed in the formation of bile, 52 ANIMAL CHEMISTRY. while we cannot tell in what precise way rectly in the food; their organism must pos they are so employed. sess the power of applying directly to the By the action of caustic alkalies allan- formation of bile all the compounds of soda toine may be resolved into oxalic acid and present in the food, and decomposable by ammonia; the same products are obtained the organic process. All the soda of the when oxanmide is acted on by the same re- animal body obviously proceeds from the agents. Yet we cannot, from the similarity food, but the food of the carnivora contains, of the products, conclude that these two at most, only the amount of soda necessary compounds have a similar constitution. In to the formation of blood; and in most cases, like manner the nature of the products among animals of this class, we may asforrned by the action of acids on choleic acid sume that only as much soda as corresponds does not entitle us to draw any conclusion to the proportion employed to form the as to the form in which its elements are blood is expelled in the urine. united together. When the carnivora obtain in their food 63. If the problem to be solved by or- as much soda as suffices for the production ganic chemistry be this, namely, to explain of their blood, an equal amount is excreted the changes which the fobod undergoes in the in the urine; when the food contains less, a animal body; then it is the business of this part of that which would otherwise be exscience to ascertain what elements must be creted is retained by the organism. added, what elements must be separated, in All these statements are most unequivoorder to effect, or, in general, to render possi- cally confirmed by the composition of the ble, the conversion of a given compound into urine in these different classes of animals. a second or a third; but we cannot expect 65. As the ultimate product of the changes from it the synthetic proof of the accuracy of of all compounds of soda in the animal body, the views entertained, because every thing we find in the urine the soda in the form of in the organism goes on under the influence a salt, and the nitrogen in that of ammonia of the vital force, an immaterial agency, or urea. which the chemist cannot employ at will. The soda in the urine of the carnivora is The study of the phenomena which ac- found in combination with sulphuric and company the metamorphoses of the food in phosphoric acids; and along with the sulthe organism, the disco-very of the share phate and phosphate of soda we never fail which the atmosphere or the elements of to find a certain quantity of a salt of ammowater take in these changes, lead at once to nia, either muriate or phosphate of ammonia. the conditions which must be united in There can be no more decisive evidence in order to the production of a secretion or of favour of the opinion, that the soda of their an organized part. bile or of the metamorphosed constituents of 64. The presence of free muriatic acid in their blood is very far from sufficing to neuthe stomach, and that of soda in the blood,,tralize the acids which are separated, than prove beyond all doubt the necessity of com- the presence of ammonia in their urine. mon salt for the organic processes; but the This urine, moreover, has an acid reaction. quantities of soda required by animals of In contradistinction to this, we find, in different classes, to support the vital pro- the urine of the herbivora, soda in precesses, are singularly unequal. dominating quantity;'and that not combined If we suppose that a given amount of with sulphuric or phosphoric acids, but blood, considered as, a compound of soda, with carbonic, benzoic, or hippuric acids. passes, in the body of a carnivorous animal, 65. These well established facts demonin consequence of the change of matter, strate that the herbivora consume a far larger into a new compound of soda, namely, the quantity of soda than is required merely!for bile, we'must assume, that in the normal the supply of the daily consumption of blood. condition of health, the proportion of soda In their food are united all the conditions for in the blood is amply sufficient to form bile the production of a second compound of soda, with the products of transformation. The destined for the support of, the respiratory soda which has been, used in the vital pro- process; and it can only be a very limited cesses, and any excess of soda must be ex- knowledge of the vast wisdom displayed in pelled in the form of a salt, after being sepa- the arrangements of organized nature which rated from the blood by the kidneys. can look on the presence of so much soda Now, if it be true, that, in the body of in the food and in the urine of the herbivora an herbivorous animal, a much larg er as accidental.,quantity of' bile is produced than corre- It cannot be accidental, that the life, the sponds. to the amount cf blood formed or developement of a plant is dependent on the transformed in the vital processes; if the presence of the alkalies which it extracts greater part of the bile, in this case, pro- from the soil. This plant serves as food to ceeds from' the non-azotised constituents of an extensive class of animals, and in these the food, then the soda of the blood which animals the vital process is again most has been formed into organized tissue (as- closely connected with the presence of these similated or metamorphosed) cannot possi- alkalies. We find the alkalies in the bile, bly suffice for the supply of the daily secre- and their presence in the animal body is the tion of bile. The soda, therefore, of the indispensable condition for the production bile of the herbivora must be supplied di- of the first food of the young animal; fc BILE IN THIE HUMAN BODY. 53 without an abundant supply of potash, the an excess of animal food (which must be production of milk becomes impossible. considered equivalent to a deficiency of_ 67. All observation leads, as appears from starch, &c.,) exercises on the separation of the preceding exposition, to the opinion, uric acid in certain individuals, may be exthat certain non-azotized constituents of the plained on this principle. If starch, sugar; food of the herbivora (starch, sugar, gum, &c., be deficient, then a part of the azotized &c.,) acquire the form of a compound of' compounds formed during the change of soda,' which, in their bodies, serves for the matter will either remain in the situation same purpose as that which we know cer- where they have been formed, in which case tainly to be served by the bile (the most they will be sent from the liver in the circuhighly cdarbonized product of the trans- lation, and therefore will not undergo the formation of their tissues) in the bodies of final changes dependent on the action of the carnivora. These substances are em- oxygen; or they will be separated by the ployed to support certain vital actions, and kidneys in some form different from the are finally consumed in the generation of' normal one. animal heat, and in furnishing means of re- 71. In-the preceding paragraphs I have sistance to the action of the atmosphere. In endeavoured to prove that the non-azotized the carnivora, the rapid transformation of constituents of food exercise a most decided their tissues is a condition of their existence, influence on the nature and quality of the because it is only as the result of the chang&e animal secretions. Whether this occur' diof matter in the body that those substances rectly; whether, that is to say, their elements can be formed, which are destined to enter take an immediate share in the act of transinto corhbination with the oxygen of the air; formation of tissues; or whether their share and in this sense we may say that the non-, in that process be an indirect one, is a quesazotized constituents of the food of the tion probably capable of being resolved by herbivora impede the change of matter, or careful and cautious experiment and observretard it, and render unnecessary, at all ation. It is possible, that the non-azotized events, so rapid a process as occurs in the constituents of food, after undergoing some carnivora. change, are carried from the intestinal canal 68. The quantity of azotized matter, pro- directly to the liver, and that they are conportionally so small, which the herbivora verted into bile in this organ, where thev require to support their vital functions, is meet with the products of the metamorclosely connected with the power possessed phosed tissues, and subsequently complete by the non-azotized parts of their food to their course through the circulation. act as means of.supporting the respiratory'This opinion appears more probable, when process; and this' consideration seems to ren- we reflect that as yet'no trace of starch or der it not improbable, that the necessity for sugar has been detected in arterial blood,'more complex organs of digestion in the her- not even in animals which had been fed exbivora is rather owing to the difficulty of clusively with these substances. We cannot rendering soluble and available for the vital ascribe to these substances, since they are processes certain non-azotized compounds wanting in arterial blood, any share in the (gum? amylaceous fibre?) than to any nutritive process; and the occurrence of thing in the change or transformation of sugar in the urine of those affected with diavegetable fibrine, albumen and caseine into betes mellitus (which sugar, according to blood; since, for this latter purpose, the less the best observations, is -derived from the complex digestive apparatus of the carnivora food) coupled with its total absence in the is amply sufficient. blood of the same patients, obviously proves 69. If, in man, when fed on a mixed diet, that starch and sugar are not, as such, taken starch perform a similar part to that which it into the circulation. plays in the body of the herbivora; if it be 72. The writings of physiologists contain assumed that the elements of starch are many proofs of the presence of certain conequally necessary to the formation of the stituents of the bile in the blood of man in a bile in man as in these animals; then it state of' health, although their quantity can follows that a part of the azotized products hardly be determined. Indeed, if we supof the transformation of the tissues in the pose 81 lbs. (58,000 grs.) of blood to pass human body, before they are' expelled through the liver every minute, and if from through the bladder, returns into the circu- this quantity of blood' 2 drops of bile (3 lation from the liver in the shape of bile, grains to the drop) are secreted, this would and is separated by the kidneys from the amount to F ifth part of the weight of the blood, as the ultimate product of the re- blood, a proportion far too small to be quan-' spiratory process. titatively ascertained by analysis. 70. When there is a deficiency of non- 73. The greater part of the bile in the body azotized matter in the food of man, this of the herbivora, and in that of man fed on form of the production of bile is rendered mixed food, appears from the preceding conimpossible. In that case, the secretions siderations to be derived from the elements must possess a different composition, and of the non-azotized food. But its formation the appearance of uric acid in the urine, the is impossible without the addition of an deposition of uric acid in the joints and in azotized body, for the bile is a compound of the bladder, as well as the influence which nitrogen. All varieties of bile yet examined, E. 54 ANIMAL CHEMISTRY. yield, when subjected to dry distillation, am- the compounds thus formed. The second monia and other nitrogenized products. division, consisting of the essential oils, Taurine and ammonia may easily be ex- camphor, empyreumatic substances, and tracted from ox bile; and the only reason antiseptics, &c., possesses the property of why we cannot positively prove that the impeding or retarding those kinds of transsame products may be obtained from the formation to which certain very complex bile of other animals is this, that it is not organic molecules are liable; transformaeasy to procure, in the case of many of tions which, when they take place out of these animals, a sufficient quantity of bile the body, are usually designated by the for the experiment, names of fermentation and putrefaction. Now, whether the nitrogenized compound The third division of medicinal substances which unites with the elements of starch to is composed of bodies, the elements of which form bile be derived from the food or from take a direct share in the changes going on the substance of the metamorphosed tissues, in the animal body. When introduced into the conclusion that its presence is an essen- the system, they augment the energy of the tial condition for the secretion of bile cannot vital activity of one or more organs; they be considered doubtful. excite morbid phenomena in the healthy Since the herbivora obtain in their food body. All of them produce a marked effect only such nitrogenized compounds as are in a comparatively small dose, and many identical in composition with the constitu- are poisonous when administered in larger ents of their blood, it is at all events clear, quantity. None of the substances in this that the nitrogenized compound which en- class can be said to take a decided share in ters into the composition of bile is derived the nutritive process, or to be employed by from a compound of proteine. It is either the organism in the production of blood; formed in consequence of a change which partly, because their composition is different the compounds of proteine in the food have from that of blood, and partly, because the undergone, or it is produced from the blood proportion in which they must be given, to or from the substance of the tissues by the exert their influence, is as nothing, comact of their metamorphosis. pared with the mass of the blood. 74. If the conclusion be accurate, that These substances, when taken into the nitrogenized compounds, whether derived circulation, alter, as is commonly said, the from the blood or from the food, talke a de- quality of the blood, and in order that they cided share in the formation of the secre- may pass from the stomach into the circutions, and particularly of the bile, then it is lation with. their entire efficacy, we must plain that the organism must possess the assume that their composition is not affected power of causing foreign matters, which are by the organic influence of the stomach. If neither parts nor constituents of the organs insoluble when given, they are rendered in which vital activity resides, to serve for soluble in that organ, but they are not decertain vital processes. All nitrogenized composed; otherwise, they would be incasubstances capable of being rendered solu- pable of exerting any influence on the blood. ble, without exception, when introduced 76. The blood, in its normal state, posinto the organs of circulation or of digestion, sesses two qualities closely related to each must, if their composition be adapted for other, although we may conceive one of such purposes, be employed by the organism them to be quite independent of the other. in the same manner as the nitrogenized pro- The blood contains, in the form of the ducts which are formed in the act of meta- globules, the carriers, as it were, of the morphosis of tissues. oxygen which serves for the production of We are acquainted with a multitude of certain tissues, as well as for the generation substances, which exercise a most marked of animal heat. The globules of the blood, influence on the act of transformation as by means of the property they possess of well as on the nutritive process, while their giving off the oxygen they have taken up elements talte no share in the resulting in the lungs, without losing their peculiar changes. These are uniformly substances character, determine generally the change the particles of which are in a certain state of matter in the body. of motion or decomposition, which state is The second quality of the blood, namely communicated to all such parts of the organ- the property which it possesses of becoming ism as are capable of undergoing a similar part of an organized tissue, and its consetransformation. quent adaptation to promote the formation 75. Medicinal and poisonous substances and the growth of organs, as well as to the form a second and most extensive class of reproduction or supply of waste in the tiscompounds, the elements of which are ca- sues, is owing, chiefly, to the presence of pable of taking a direct or an indirect share dissolved fibrine and albumen. These two in the processes of secretion and of trans- chief constituents, which serve for nutriformation. These may be subdivided into tion and reproduction of matter, in passing three great orders; the first (which includes through the lungs are saturated with oxygen, the metallic poisons) consists of substances or, at all events, absorb so much from the which enter into chemical combination with atmosphere as entirely to lose the power of certain parts or constituents of the. body, extracting oxygen from the other substances while the vital force is insufficient to destroy present in the blood. ORGANIC REMEDIAL AGENTS. 55 77. We know for certain that the globules into any such chemical union with the conof the venous blood, when they come in con- stituents of the blood as puts an end to the tact with air in the lungs, change their co- vital activity; assuming, further, that it is lour, and that this change of colour is ac- not in a condition of transformation capable companied by an absorption of oxygen; and of being communicated to the constituents that all those constituents of the blood which of the blood or of the organs, and of conpossess in any degree the power of combining tinuing in them; assuming, lastly, that it is with oxygen, absorb it in the lungs, and be- incapable, by its contact with the living come saturated with it. Although in contact parts, of putting a stop to the change of with these other compounds, the globules, matter, the transformation of their elements; when arterialized, retain their florid, red co- then, in order to discover the modus opelour in the most minute ramifications of the randi of this class of medicinal agents, noarteries; and we observe them to change their thing is left but to conclude that their colour, and to assume the dark red colour elements take a share in the formation of which characterizes venous,blood, only certain constituents of the living body, or during their passage through the capillaries. in the production of certain secretions. From these facts we must conclude that the 81. The vital process of secretion, in so constituents of arterial blood are altogether far as it is related to-the chemical forces, has destitute of the power to deprive the arte- been subjected to examination in the precedrialized globules of the oxygen which they ing pages. In the carnivora we have reahave absorbed from the air; and we can son to believe, that without the addition of. draw no other conclusion from the change any foreign matter in the food, the bile and of colour which occurs in the capillaries, the constituents of the urine are formed in than that the arterialized globules, during those parts where the change of matter takes their passage through the capillaries, return place. In other classes of animals, on the to the condition which characterized them other hand, we maay suppose that in the orin venous blood; that consequently, they gan of secretion itself, the secreted fluid is give up the oxygen absorbed in the lungs, produced from certain matters conveyed to and thus acquire, the power of combining it; in the herbivora, for example, the bile is with that element afresh. formed from the, elements of starch along 78. We find, therefore, in arterial blood, with those of a nitrogenized product of the albumen, which, like all the other consti- metamorphosis of the tissues. But this suptuents of that fluid, has become saturated position by no means excludes the opinion, with oxygen in its passage through the that in the carnivorathe products of the melungs, and oxygen gas, which is conveyed tamorphosed tissues are resolved into bile, to every particle in the body in chemical uric acid, or urea, only after reaching the combination with the globules of the blood. secreting organ; nor the opinion that the As far as our observations extend (in the elements of the non-azotized food, conveyed developement of the chick during incuba- directly by the circulation to every part of tion,) all the conditions seem to be here the body, where change of matter is going united which are necessary to the formation' on, may there unite with the elements of the of every kind of tissue; while that portion metamorphosed tissues, to form the constituof oxygen which is not consumed in the ents of the bile and of the urine. growth or reproduction of organs combines 82. If we now assume,.that certain mewith the substance of the living parts, and dicinal agents may become constituents of produces, by its union with their elements, secretions, this can only occur in two ways. the act of transformation which we have Either'they enter the circulation, and take a called the change of matter. direct share in the change of matter in so 79. It is obvious, that all compounds, of far as the;r elements enter into the compowhatever kind, which are, present in the sition of the new products; or they are con- capillaries, whether separated there, or in- veyed to the organs of secretion, where they troduced by endosmosis or imbibition, if not exert an influence on the formation or on altogether incapable of uniting with'oxygen, the quality of a secretion by the addition of must, when in contact with the arterialized their elements. globules, the carriers of oxygen, be affected In either case, they must lose in the orexactly in the same way as the solids form- ganism their chemical character; and we ing part of living organs. These com- know with sufficient certainty, that this class pounds, or their elements, will enter into, of medicinal bodies disappear in the body combination with oxygen, and in this case without leaving a trace. In fact, if we asthere will either be no change of matter, or cribe to them any effect, they cannot lose that change will' exhibit itself in another their peculiar character by the action of the form, yielding products of a different kind. stomach; their disappearance, therefore, pre80. The conception, then, of a change in supposes that they have been applied to certhe two qualities of the blood above alluded tain purposes, which cannot be imagined to to, by means of a foreign body contained in occur without a change in their composition. the blood or introduced into the circulation 83. Now, however limited may be our (a medicinal agent) presupposes two kinds knowledge of the composition of the differof operation. ent secretions, with the exception of the Assuming that the remedy cannot enter bile, this much is certain, that all the secre .56.' - I.Jf~ANIMAL CHEMISTRY. tions contain nitrogen chemically combined. nitrogenized compounds, products of the They pass into fetid putrefaction, and yield vital process in plants, when introduced into either in this change, or in the dry distillation, the animal body, may be employed by the ammoniacal products. Even the saliva, organisni exactly in the same way as the when acted upon by caustic potash, disen- nitrogenized products of the metamorphosis gages ammonia freely.- of the animal tissues themselves. If hippu84. Medicinal or remedial agents may be ric and uric acids, or any of their elements, divided into two classes, the nitrogenized can take a share, for example, in the formand the non-nitrogenized. The nitrogenized ation and supply of bile, we must allow the vegetable principles,,whose composition same power to other analogous- nitrogenized differs from that of the proper nitrogenized compounds. elements of nutrition, also produced by a We shall never, certainly, be able to disvegetable organism, are distinguished, be- cover how men were led to the use of the yond all others, for their powerful action on hot infusion of the leaves of a certain shrub the animal economy. (tea) or of a decoction of certain roasted The effects of these substances are singu- seeds (coffee.) Some cause there must be, larly varied; from the mildest form of the which would explain how the practice has action of aloes, to the most terrible poison, become a necessary, of life to whole nations. strychnia, we observe an endless variety of But it is surely still more remarkable, that different action. the beneficial effects of both plants on the With the exception of three, all these health must be ascribed to one and the same substances produce diseased conditions in substance, the presence of which in two the healthy organism, and are poisonous in vegetables,, belonging to different natural certain doses. Most of them are, chemi- families, and the produce of different quarcally speaking, basic or alkaline. ters of the globe, could hardly have presented No remedy, devoid of nitrogen, possesses itself to the boldest imagination. Yet recent a poisonous action in a similar dose., researches have shown, in such a manner as 85. The medicinal or poisonous action of to exclude all doubt, that caffeine, the pecuthe nitrogenized vegetable principles has a liar principle of coffee, and theine, that of fixed relation to their composition; it can- tea, are, in all respects, identical. not be supposed to be independent of the It is not less worthy of notice, that the nitrogen they' contain, but is certainly not in American Indian, living entirely on flesh, direct proportion to the quantity of nitrogen. discovered for himself, in tobacco smoke, a Solanine (38,) and picrotoxine (39,)which means of retarding the change of matter in contain least nitrogen, are powerful poisons. the tis,sues of his body, and thereby of makQuinine (40) contains more nitrogen than ing hunger more endurable; and that he morphia (41.) Caffeine (42,) and theobro- cannot withstand the action of brandy, mine the most highly nitrogenized of all which, acting as an element of respiration, vegetable principles, are not poisonous.,puts a stop to the change of matter by per86. A nitrogenized body, which exerts, forming the function which properly.belongs by means of its elements, an influence on to the products of the metamorphosed tisthe formation or on the quality of a secre'- sues. Tea and coffee were originally met tion, must, in regard to its chemical charac- with among nations whose diet is chiefly ter, be capable of taking the same share as vegetable. the nitrogenized products of the animal body 87. Without entering minutely into the do in the formation of the bile; that is,. it medicinal action of caffeine, (theine,) it will must play the same part as a product of the surely appear a most striking fact, even if vital -process.'On the other hand, a non- we were to deny its influence on the proazotized medicinal agent, in so far as its ac- cess of secretion, that this substance, with tion affects the secretions, must be capable the. addition of oxygen and the elements of of performing in the animal body the same water, can yield taurine, the nitrogenized part as that which we have ascribed in the compound peculiar to bile: formation of the bile, to the non-azotized 1 at. caffeine or theine —CSN2H 502 elements of food. 9 at. water. - - H 909 Thus, if we suppose that the elements of'9 at. oxygen.. - 9 hippuric or uric acids are divided from the CsN2H402___ substance of the organs in which vitality 2 at.taurine - 2(C4NH701i) resides; that as products of the transformation of these organs they lose the vital A similar relation exists in the case of the character, without losing' the capacity of peculiar principle of asparagus and of al undergoing changes under the influence of thea, asparaine; which also, by the addithe inspired oxygen, or of the apparatus of tion of oxygen and theelements of water, secretion; we can hardly doubt that similar the elements oftaurine. 1 at. asparagine CN2H 806 * This consideration or comparative view has 6 at. water -- H 606 led lately to a more accurate investigation of the 8 at. oxygen 08 composition of picrotoxine, the poisonous principle CSN2H14020~ of cocculus indicus; and M. Francis has disco vered the existence of nitrogen in it, hitherto overlooked, and has also determined its amount.' The addition of the elements ot water and ACTION OF VEGETABLES. 57 of a certain quantity of oxygen to the ele- mical sense-and it is this alone which the ments of theobromine, the characteristic preceding remarks are intended to showprinciple of the cacao, bean, (theobroma caffeine or theine, asparagine, and theobrocacao,) yields the elements of taurine and mine are in virtue of their composition better urea, of taurine, carbonic acid, and ammo- adapted to this purpose than all other nitronia, or of taurine and uric acid: genized vegetable principles. The action of 1 at. theobromine C'SN6H'004 these substances, in ordinary circumstances, 22 at. water - H22022>_ is not obvious, but it unquestionably exists. 16 at. oxygen - - 6) 89. With respect to the action of the C18N6 H32042 other nitrogenized vegetable principles, such as quinine, or the alkaloids of opium, &c., at. C u re2 -402 which manifests itself, not in the processes I at. urea NC2 N2H4 02 of secretion, but in phenomena of another 6C81X6IN32042 kind, physiologists and pathologists enteror_ \ tain no doubt that it is exerted chiefly on 1 at. theobromine tC'81N6H 1004 the brain and nerves. - This action is com24 at. water _- 240(4 monly said to be dynamic-that is, it acce16 at. oxygen - 0l65 lerates, or retards, or alters in some way the 0C'516H3o4 phenomena of motion in animal life. If we aCtaI SNe]6rH3S10 404 reflect that this action is exerted by sub(4 at. taurine C'6N4H1~04~0'stances which are material, tangible and e<2 at. carbonic acid C2 04 ponderable; that they disappear in the or(2 at. ammonia N 2H 6 ganism; that a double dose acts more powerC18N6in34044 fully than a single one; that, after a time, a or- fresh dose must be given, if we wish to proI at. theobromine C'sN6H'004) duce the action a second time; all these 8 at. water - 8,0 considerations, viewed chemically, permit 14 at. oxygen - 0''4) only one form of explanation; the supposiCl8N6Hs1026 tion, namely, that these compounds, by means of their elements, take a share in the 2 at. taurine Cs N2H14020 formation of new, or the' transformation of - il at. uric acid C'0N4HI4 06 existing brain and nervous matter. Ci8N6H'8026 However strange the idea may, at first sight, appear, that the alkaloids of opium or. 88. To see how the action of caffeine, as- of cinchona bark, the elements of codeine, paragine, theobr6mine, &cr, may be ex- morphia, quinine, &c., may be converted plained, we must call to mind that the chief into constituents of brain and nervous matconstituent of the bile contains only 3-8 per ter, into organs of vital energy, from which cent. of nitrogen, of which only the half, or the organic motions of the body derive their 1'9 per cent., belongs to the taurine. origin; that these substances; form a conBile contains, in its natural state, water stituent of that matter, by the removal of and solid matter, in the proportion'of 90 which the seat of intellectual life, of sensaparts by weight-of the former to 10 of the tion, and of consciousness, is annihilated; latter. If we suppose these 10 parts by it is nevertheless certain, that all these weight of solid matter to be' choleic acid, forms of power and activity are most closely with 3'87 per cent. of nitrogen, then 100 dependent, not only on the existence, but parts of fresh bile will contain 0'1.71 parts also on a certain quality of the substance of of nitrogen in the shape of taurine. Now the brain, spinal marrow, and nerves; insothis quantity is contained in 0'6 parts of much that all the manifestations of the life caffeine: or 2,-36ths grains of caffeine can or vital' energy of these modifications of give to an ounce of bile the nitrogen it con- nervous matter, which are recognized as the tains in the form of taurine. If an infusion phenomena of motion, sensation, or feeling,' of tea contain no more than the,-1th of a assume another form as soon as their comgrain of caffeine, still, if it contribute in position is altered. The animal organism point of fact to the formation of bile, the has produced the brain and nerves out of action, even of such a quantity, cannot be compounds furnished to it by vegetables; looked upon as a nullity. Neither can it be it is the constituents of the food of,the denied that in the case of an excess of non- animal, which, in consequence of a series azotized food and a deficiency of motion, of changes, have assumed the properties and which is required to cause the change of the structure which we find in the brain and matter in the tissues, and thus to yield the nerves. nitrogenized product which enters into the 90. If it must be admitted as an undecomposition of the bile; that in such a con- niable truth, that the substance of the brain dition, the health may be benefited by the and nerves is produced fiom the elements use of compounds which are capable of of vegetable albumen, fibrine and caseine, supplying -the place of the nitrogenized pro- either alone, or with the aid of the elements duct produced -in the healthy state of the of non-azotized food or of the fat formed body, and essential to the production of an from the latter, there is nothing'absurd in nmpcrtant element of respiration. In a che- the opinion, that other constituents of vege8 s.58 ~ANIMAL CHEMISTRY. tables, intermediate in composition between mediate between the compounds of proteine the fats and the compounds of proteine, and the fats. may be applied in the organism to the same 93. In contradistinction to their chemical purpose. character, we find that the substance of the 91. According to the researches of Fremy., brain exhibits the characters of an acid. It the chief constituent of the fat found in the contains far more oxygen than the- organic brain is a compound of soda with a peculiar basis or alkaloids. We observe, that qulacid, the cerebric acid, which contains, in nine and cinchonine, morphia and codeine, 100 parts, strychnia and brucia, which are, respecCarbon..66 tively, so nearly alike in composition, if Hydrogenl1. "... 10~6, they do not' produce absolutely the same Nitrogen..23 effect, yet resemble each other in their Phosphorus. 09 action more than those which differ more Oxygen.19 5 widely in composition. We find that their't is easy' tosetenergy of action-diminishes, as the amount'It is easy to see that the composition of of oxygen they contain increases (as in the cerebric acid differs entirely, both from that case of narcotine,) and that, strictly speakof ordinary fats and, of the compounds of ing, no one of them can be entirely replaced proteine. -Common fats contain no nitrogen, by another. There cannot be a more dewvhile the compounds of proteine contain cisive proof of the nature of their action nearly 17 per cent. Leaving the phos- than this last fact; it must'stand in the phorus out of view, the, composition of this closest relation to their composition. If ncid approaches most nearly'to that of these compounds, in point of fact, are capacholeic acid, although these two compounds ble of taking a share in the formation or in are quite distinct. the alteration of the qualities of brain -and 92. Brain and nervous matter is, at all nervous matterI, their action on the healthy events iformed in a manner similar to that as well as the deceased organism admits of in which bile is produced; either by the a surprisingly simple explanation. If we separation of a highly nitrogenized com- are not tempted to deny, that th~e chief conpound from the elements of blood, or by stituent of soup may be applied. to a purpose the combination' of a nitrogenized product corresponding to its composition in the of. the vital process with a non-azotized" human body, or that the organic'constituent compound (probably, a fatty body.) All of bones may be so employed in the body that has been said in the preceding pages of the dog, although that substance (gelanon the various, possible ways by which the tine in both cases) is absolutely incapable bile might be supposed. to be formed, all the of yielding blood; if, therefore, nitrogenized conclusions which we attained in regard compounds, totally different from the comto the co-operation of' azotized and non- pounds of proteine, may be employed for azotized elements of food, may be applied purposes corresponding to their composiwith equal justice and equal probability to tion; we may thence conclude that a prothe formation and production of the nervous duct of vegetable life;'also different from substance. ~ proteine, but similar to a constituent of the We mlust not forget that, in whatever animal body, may be employed by the, organ-,ight we may view the vital operations, the ism in the same way and for the same purproduction of nervous matter from blood pose as the natural product,' originally presupposes a change in the composition formed by the vital energy of the animal and qualities of the constituents of blood. organs, and that indeed from a vegetable That such a change occurs is ascertain as substance. that the existence of the nervous matter The time is not long gone by, when we cannot be denied. In this sense, we must had not the very slightest conception of the assume, that from a compound of proteine cause of the various effects of opium, and may be formed a first, second, third, &c., when the action of cinchona bark was product before a certain number of its ele- shrouded in incomprehensible obscurityl ments can become constituents of the nerv- Now that we know that these effects are onus matter; and it must be considered as caused by crystallizable compounds, which quite certain, that a product of the vital pro- differ as much in composition as in. their cess in a plant, introduced into the blood, action on the system; now that we know will, if its composition be adapted to this the substances to which the medicinal or purpose,. supply the place of the first, se- poisonous energynmust be ascribed, it would cond, or third' product of the alteration of argue only want of sense to consider the the compound of proteine. Indeed it can- action of these substances inexplicable; and not be -considered merely accidental, -that to do so, as many have done, because they the composition of the most active remedies, act in very minute doses, -is as unreasonable namely, the vegetable alkaloids, cannot be as it would be to judge of the sharpness of shown to be related to that of any consti- a razor by its weight. tuent of the body, except only the substance 94. It'would serve no purpose to give of the nerves and brain. All of these con- these considerations a greater extension at tain a certain quantity of nitrogen, and, in present. However hypothetical they may regard to their composition, they are ifnter- appear, they only deserve attention in so far COMPOSITION OF NERVOUS MATTER. 59 as they point out the way which chemistry expressed doubts of the peculiar and dispursues, and which she ought not to quit, tinct character of cerebric acid, a substance if she would really be of service to phy- which, from its amount of carbon and siology and pathology. The combinations hydrogen, and from its external characters, of the chemist relate to the change of mat- resembles a nitrogenized fatty acid. But a ter, forwards and backwards, to the con- nitrogenized fat, having an acid character, version of food into the various tissues and is, in fact, no anomaly. Hippuric acid is in secretions, and to their metamorphosis into many of its characters'very similar to the lifeless compounds; his investigations ought fatty' acids, but is essentially distinguished to tell us what has taken place and what from them by containing nitrogen. The can. take place in the body. It is singular organic constituents of bile resemble the that we find medicinal agencies all de-' acid resins in physical characters, and yet pendent on certain matters, which differ in contain nitrogen. The organic alkalies are composition; and if, by the introduction of intermediate in their physical characters bea substance, certain abnormal conditions are tween the fats and resins, and they all conrenderednormal, itwill be impossibleto reject lain nitrogen. A nitrogenized fatty acid is the opinion, that this phenomenon depends as little improbable as' the existence of a on a change in the composition of the consti- nitrogenized resin with the characters of a tuents of the diseased organism, a change in base. which the elements of the remedy take a 97. An accurate investigation would proshare; a share similar to that which the vege- bably discover differences in the composition table elements of food have taken in the for- of the brain, spinal marrow and nerves. mation of fat, of membranes, of the saliva, According to the observations of Valentin, of the seminal fluid, &c. Their carbon, hy- the quality of the cerebral and nervous sub, drogen, or nitrogen, or whatever else belongs stance is very rapidly altered from the period to their composition, are derived from the of death, and very uncommon precautions vegetable organism; and, after all, the action would be required for -the separation of and effects of quinine, morphia, and the. foreign matters not properly belonging to vegetable poisons in general, are no hypo- the substance of the spinal marrow or brain. theses. Bbt, however difficult it may appear, the 95. Thus, as we may say, in a certain investigation seems yet to be practicable. sense, of caffeine, or theine, and asparagine, We know, in the meantime, that all expe&c., as well as of the nonLazotized elements rience is against the. notion of a large of food, that they are food for the liver, amount of carbon and hydrogen in the subsince they contain the' elements, by the pre- stance of the brain. The absence of nitrosence of which that organ is enabled to per- gen as an element of the cerebral and form its functions, so we may consider nervous matter, appears, at all events, imthese nitrogenized compounds, so remark- probable.> This substance, moreover, canable for their action on the brain and on the not be classed with ordinary fats, because substance of the organs of motion, as we find the cerebric acid combined with elements of food for the organs as yet un- soda, whereas, all fats are compounds of known, which are destined for the meta- fatty acids with oxide of glycerule. In remorphosis of the. constituents of the blood gard to the phosphorus of the brain, we can into nervous substance and brain.. Such only guess as to the form'in which the phosorgans there must be in the animal body, phorus exists. W alchner observed recently and if, in the diseased state, an abnormal that bubbles of spontaneously inflammable process of production or transformation of phosphuretted hydrogen were disengaged the constituents of cerebral and nervous mat- from the trough of a spring in Carlsruhe, ter has been established; if, in the organs in- on the bottom of which fish had putrefied'; tended for this purpose, the power of form- and gases containing phosphorus have also ing that matter out of the constituents of been observed among the products of the blood, or the power of resisting an abnormal putrefaction of the brain.* degree of activity in its decomposition or transformation, has been diminished; then, in a chemical sense, there is no objection to * The curator of the museum at Geneva gave to M. Leioyer, apothecary, a large quantity of the opinion', that substances of a composi- spirit of wine, which had been used for the pre. tion analogous to that of nervous or cerebral servation cf fishes; and which he undertook to matter, and, consequently, adapted to form purify. EIe distilled from it amixture of chloride of that matter, may be employed, instead of calcium and quicklime, and evaporated the residue the substances produced from the blood, in the air, over a fire. As soon as the mass had acquired a certain consistence. and a higher temeither to furnish the necessary resistance, or perature, a prodigious quantity of spontaneously to restore the normal condition. inflammable phosphoretted hydrogen was dis. 96. Some physiologists and chemists have engaged. (Dunas, V. 267.) 60 ANIMAL CHEMISTRY. PART III. THE PHENOMENA OF MOTION IN THE ANIMAL ORGANISM. I. IT might appear an unprofitable task to changes the direction and force of the atadd one more to *the innumerable forms traction of cohesion, destroys the cohesion under which the human intellect has viewed of the nutritious compounds, and forces the the nature and essence of that peculiar cause new compounds to assume forms altogether which must be considered as the ultimate different from those which are the result of source of the phenomena which characterize the attraction of cohesion when' acting freely, vegetable and animal life, were it not that that is, without resistance. certain conceptions present themselves as The vital force is also manifested as a necessary deductions from the views on this force of attraction, inasmuch as the new subject developed in the introduction to the compound produced by the change of. form first part of this woik. The following pages and structure in the food, when'it has a will be devoted to a more detailed examina- composition identical with that of the living tion of these deductions. It must be ad- tissue, becomes a part of that tissue. mitted here, that all these conclusions will Those newly-formed compounds, whose lose their force and significance, if it can be composition differs from that of the living proved that the cause of vital activity has tissue, are. removed from the situation in in its'manifestations nothing in common with which they are formed, and, in the shape other known causes which produce motion of certain secretions, being carried to other or change of form and structure in matter, parts of the body, undergo in contact with But a comparison of its peculiarities with these a series of analogous changes. the modus operandi of these other causes, The vital force is manifested in the form cannot, at all events, fail to be advantageous, of resistance, inasmuch as by its presence inasmuch as the nature and essence of in the living tissues- their elements acquire natural phenomena are recognizable, not by the power of withstanding the disturbance abstraction, but only by comparative obser- and change in their form and composition, vations. which external agencies tend to produce; a If the vital phenomena be considered as power which, simply as chemical. cornmanifestations of a peculiar force, then the pounds, they do not possess. effects of this force must be regulated by As in the case of other forces, the concertain laws, which laws may be investi- ception of an unequal intensity of the vital gated; and these laws must be in.harmony force comprehends not only an unequal with the universal laws of resistance and capacity for growth in the mass and an motion, which preserve in their courses the unequal power of overcoming chemical reworlds of our own and other systems, and sistance,but also an inequality in the amount which also determine changes of form and of that resistance which the parts or constructure in material bodies; altogether in- stituents of the living tissue oppose to a dependently of the matter in which vital change in their form and composition, from activity appears to reside, or of the form in the action of new external active causes of which vitality is manifested. change; just as the force of cohesion or of The vital force in a living animal tissue affinity is in direct proportion to the resistappears as a cause of growth in the mass, ance which these forces oppose to any exand of resistance to those external agencies ternal cause, mechanical or chemical, tendwhich tend to alter the form, structure, and ing to separate the molecules, or the elements composition of the substance of the tissue of an existing compound. in which the vital energy resides. The manifestations of the vital force are This force further manifests itself as a dependent on a certain form of the tissue in cause of motion and of change in the form which it resides, as well as on a fixed colnand structure of material substances, by the position in the substance of the living tissue. disturbance and abolition of the state of rest The capacity of growth in a living tissue in which those chemical forces exist, by is determined by the immediate contact with which the elements of the compounds con- matters adapted to a certain decomposition, veyed to the living tissues, in the form of or the elements of which are capable of befood, are held together. coming component parts of the tissue in The vital force causes a decomposition of which vitality resides. the constituents of food, and destroys the' The phenomenon of growth, or increase force of attraction which is continually ex- in the mass, presupposes that the acting erted between their molecules; it alters the vital force is more powerful that the resist direction of the chemical forces in such wise, ance which the chemical force opposes to that the elements of the constituents of food the decomposition or transformation of the arrange themselves in another form, and elements of the food. combine to produce new compounds, either The mani'estatlons. of the vital force are identi:al in composition with the living tis-' dependent on. a certain temperature. Neithet sues, or differing from them; it further in a plant nor in an'animal do vital phe. MOTION IN THE* ANIMAL ORGANISM. 61 nomena occur when the temperature is once appears as the cause of change of lowered to a certain extent. place in the stone. which acquires motion, The phenomena of vitality in a living or- or falls. Resistance is invariably the result ganism diminish in intensity when heat is of a force in action. abstracted, provided the lost heat be not re- According as the stone is allowed to fall stored by other causes. during a longer or shorter time, it acquires Deprivation of food soon puts a stop to properties which it had not while at rest; it all manifestations of vitality. acquires, for example, the power of overThe contact of the living tissues with the coming more feeble or more powerful obstaelements of nutrition is determined in the cles, or that of communicating motion to' animal body by a mechanical force produced bodies in a state of rest. within the body, which gives to certain or- If it fall from a certain height it makes a gans the power of causing change of place, permanent impression on the spot on which of producing motion, and of overcoming it falls; if it fall from a still greater height mechanical resistance. (during a longer time) it perforates the table; We may communicate motion to a body its own motion is communicated to a certain at rest by means of a number of forces, very number of the particles of the wood which different in their manifestations. Thus, a now fall along with the stone itself.'The time-piece may be set in motion by a falling stone, while at rest, possessed none of these weight, (gravitation,) or.bya bent spring properties. (elasticity.) Every kind of motion may be The velocity of the falling body is always produced by the electric or magnetic force, the effect of the moving force, and is, ceteris as' well as by chemical attraction; while we paribus, proportional to the force of gravicannot sav, as long as we only consider the tation.' manifestation of these forces in the pheno- A body, falling freely, acquires at the end menon or result produced, which of these of one second a velocity of 30 feet. The various causes of change of place has set same body, if falling on the moon,.would the body in motion. acquire in one second only a velocity of In the animal organism we are acquainted 5oth of a foot= inch, because in the moon with only one cause of motion; and this is the intensity of gravitation (the pressure the same cause which determines the growth acting on the body, the moving power) is of living tissues, and gives them the power 360 times smaller. of resistance to external agencies; it is the If the pressure continue uniform, the vevital force. locity is directly proportional to it; so that, In order to attain a clear conception of for example, the body falling 360 times these manifestations of the vital force, so slower, will, after 360 seconds, have the different in form, we must bear in mind,' same velocity as the other body after one that every known force is recognized by two second. conditions of activity, entirely different in Consequently, the effect is proportional, the phenomena they offer to the attention not to the moving force alone, nor to the of the Observer.. time alone, but to the pressure multiplied The force of gravitation) inherent in the into the time, which is called the mnomentvom particles of a stone, gives to them a con- of force. tinual tendency to move towards the centre In two equal masses the velocity expresses of the earth. the momentum of force. But under the This effect of gravitation becomes inap- same pressure a body moves more slowly preciable to the senses when the stone, for as its mass is greater; a mass twice as great example, rests upon a table, the particles of requires, in order to attain in the same time which oppose a resistance to the manifesta- an equal velocity, twice the pressure; or, tion of its gravitation. The force of gravity, under the single pressure, it must continue however, is constantly present, and mani- in motion twice as long. fests itself as a pressure on the supporting In order, therefore, to have an expression body; but the' stone remains at rest; it has for the whole effect produced, we must mulno motion. The manifestation of gravity in tiply the mass into the velocity. This prothe state of rest we call its weight.' duct is called the amount of motion. That which prevents the stone from falling The amount of motion in a given body is a resistance produced by the force of at- must in all cases correspond exactly to the traction, by which the particles of the wood momentum of force. cohere together; a mass of water would not'These two, the amount of motion and the prevent the.fall of the stone. momentum of force, are also called simply If the force which impelled the mass of force; because we suppose that a less presthe stone towards the centre of the earth sure acting, for example, during 10 seconds, were greater than the force of cohesion in is equal to a pressure ten times greater, actthe particles of the wood, the latter would ing only during one second. be overcome: it would be unable to prevent The momentum of mnotion in mechanics the fall of the stone. signifies the effect of a moving force, withWhen we remove the support, and with out reference to the time (velocity) in which it the force which has prevented the mani- it was manifested. If one man, for example, festation of the force of gravity, the latter at raises 30 lbs. to a height of 100 feet, and a se — F 62 ANIMAL CHEMISTRY. cond one 30 lbs. to a height of 200 feet; then Motion, by whatever cause produced, the latter has expended twice as much force cannot in itself be annihilated; it may indeed as the former. A third who raises 60 lbs. to become inappreciable to the senses, but even a-height of 50 feet, expends no more force when arrested by resistance (by the manithan the first did in raising 30 lbs. to the festation of an opposite'force,) its effect is height of 100 feet. The momentum of mo- not annihilated. The falling stone, by means tion of the first (30X 100) is equal to that of the amount of motion acquired in its deof the third (60X50) while that of the se- scent, produces an effect when it reaches cond (30 X200) is twice as great. the table. The impression made on the Momentum of force and momentum of wood, the' velocity communicated by its motion in mechanics are therefore expres- parts to those of the wood, all this is its effect. sions or measures for effects of force, having If we transfer the conceptions of motion, reference to the velocity attained in a given equilibrium, and resistance, to the chemical time, or to a given space; and in this sense forces, which, in their modus operandi, apmay be applied to the effects of all other proach to the vital force infinitely nearer causes of motion, or of change in form and than gravitation does, we know with the structure, however great or however small utmost certainty, that they are active only may be the space or the time in which their in the case of immediate contact. We know, effects are displaved to the senses. also, that the unequal capacity of chemical Every force, therefore, exhibits itself in compounds to offer resistance to external matter either in the form of resistance to disturbing influences. to those of heat, or of external causes of motion, or of change in electricity, which tend to separate their parform and structure; or as a moving force ticles, as well as their power of overcoming when no resistance is opposed to it; or, resistance in other compounds (of causing finally, in overcoming resistance. decomposition); that, in a word, the active One and the same force communicates force in a compound depends on a certain motion and destroys motion; the former order or arrangement, in which its elementwhen its manifestations are opposed by no ary particles touch each other. resistance; th'e latter, when, it puts a stop to The same elements, united in a different the manifestation of some other cause of order, when in contact with other commotion, or of change in form and structure. pounds, exert a most unequal power of ofEquilibrium or rest is that state of activity fering or overcoming resistance. In one in which one force or momentum of motion form the force manifested is available (the is destroyed by an opposite force or momen- body is active, an acid, for example); in tum of motion. another not (the body is indifferent, neutral); We observe both these manifestations of in a third form, the momentum of force is activity in that force which gives to the liv- opposed to that of the first (the body is ing tissues their peculiar properties. active, but a base). The vital force appears as a moving force If. we alter the arrangement of the eleor cause of motion when it overcomes the ments, we are able to separate the constituchemical forces (cohesion and affinity) which ents of a compound by means of another act between the constituents of food, and active body; while the same elements, united when it changes the position or place in in their original order, would have opposed which.their elements occur; It is manifested an invincible resistat. ce to the action of the'as a cause of motion in overcoming the che- decomposing agent. mical attraction of the constituents of food, In the same way as two equal inelastic and is,'further, the cause which compels masses, impelled with equal velocity from them to combine in a new arrangement, and opposite points, on coming into contact are to assume new forms. brought to rest; in the same way, therefore, It is plain that a part of the anilnal body' as two equal and opposite momenta of mopossessed of vitality, which has therefore the tion mutually destroy each 6ther; so may power of overcoming resistance, and of giv- the'momentum of force in a chemical coming motion to the elementary particles of the pound be destroyed in whole or in. part by food, by means of the vital force manifested an equal or unequal, and opposite momenin itself must have a momentum of tmotion, tumrn of force in a second compound. But which is nothing else than the measure of it cannot be. annihilated as long as the arthe resulting motion or change in form and rangement of the' elementary particles, by structure. which its inherent force was manifested, is We know that this momentum of motion not changed. in the- vital force, residing in a liviing part, The chemical force of sulphuric acid is may be employed in giving motion to bodies present in sulphate of lime as entire as in at rest, (that is, in causing decomposition, oil of vitriol. It is not appreciable by the or overcoming resistance,) and if thevital senses; but if the cause be removed which force is analogous in its manifestations to prevented its manifestation, it appears in its other forces, this momentum of motion must full force in the compound in which it probe capable of being conveyed or communi-' perly resides. cated by matters, which in themselves do Thus the force of cohesion in a solid may not destroy its effect by an opposite mani- disappear, to the senses, from the action of" festation of force. a chemical force, (in solution,) or of heat MOTION IN THE ANIMAL ORGANISM. 63 (in fusion,) without being in reality annihi- compound) seem to depend on a certain lated'or even weakened. If we remove the order in which the elementary particles are opposing force or resistance, the force of co- united together,' so experience tells us, that hesion appears unchanged in crystallization. the vital phenomena are inseparable from By means of the electrical force, or that matter; that the manifestations of the vital of heat, we can give the most varied direc- force in a living part are determined by a tions to the manifestations of chemical force. certain form of that part, and by a certain By these means we..can fix, as it were, the arrangement of its elementary particles. If order in which the elementary particles we destroy the form, or alter the composishall unite. Let us remove the cause (heat tion of the organ, all manifestations of vior electricity) which has turned the balance tality disappear. in favour of the weaker attraction in one There is nothing to prevent us fromi condirection, and the stronger attraction will sidering the vital force as a peculiar ptoshow itself continually active in another perty, which is possessed by certain matedirection; and if this stronger attraction can rial bodies, and becomes sensible when their overcome the vis inertiaT of the elementary elementary particles are cdombined in a cerparticles, they will unite in a new form, tain arrangement or form. and a new compound of'different properties This supposition takes from the vital must be the result. phenomena nothing of their wonderful peIn:compounds of this kind, in which, culiarity; it may therefore be considered as therefore,.-the free manifestation or the a resting point, from which an investigation chemical force has been impeded by other into these phenomena, and the laws which forces, a blow, or mechanical friction, or the. regulate them, may be commenced; exactly contact of a substance, the particles of as we consider the properties and laws of which are in a state of'motion (decomposi- light to be dependent on a certain luminifetion, transformation,) or any external cause, rous matter, or other, which has no further whose activity is added to' the stronger at- connexion with the'laws ascertained by intraction of the elementary particles in an- vestigation. other direction, may suffice to give the pre- Considered under this form, the vital force ponderance to this stronger attraction, to unites in its manifestations all the peculiariovercome the vis inertire, to alter the form ties.of chemical forces, and of the not less and structure.of the compound, which are wonderful cause, which we regard as the the result of foreign causes, and to produce ultimate origin of electrical phenomena. the resolution of the compound into' one or The vital force does not act, like the force more new compounds with altered proper- of gravitation or the magnetic force, at inties.' finite distances, but, like chemical forces, it Transformations, or as they may be called, is active only in the case of immediate conphenomena of' motion, in compounds of tact. It becomes sensible by means of an this class-, may be effected by means of the aggregation of material particles. free and available chemical force of another A living part acquires, on the above supchemical. compound, and that without its position, the capacity of offering and of manifestation being enfeebled or arrested by overcoming resistance, by the combination resistance. Thus the equilibrium in theat- of its elementary particles in a certain foim;,traction between the elements of cane-sugar'and as long as its form and composition-are is destroyed by contact with a very small not destroyed by opposing forces, it must requantity of sulphuric acid, and it is con- tain its energy uninterrupted and unimpaired. verted into grape-sugar. In the same way When, by the act of manifestation of this we see the elements of starch, under the energy in a living part, the elements of the same influence, arrange thetnselves with food are made to unite in the same form and those of water in a new form, while the structure as the living organ possesses, then sulphuric acid, which has served to produce these elements acquire the same powers. these transformations, loses nothing of its By this combination, the vital force inherent chemical character., In regard to other sub- in them is enabled to manifest itself fieely, stances on which it acts, it remains as active and may be applied in the same way as that as before, exactly as if it had exerted no of the previously existing tissue..sort of influence on the cane-sugar or starch. If, now,'we bear in mind; that'all matters, In contradistinction to the manifestions of' which serve as food to living organisms are the -so-called mechanical forces, we have compounds of-two or more elements, which recognized in the chemical forces causes of *are kept together by certain chemical forces; motion and of change in form and structure, if we reflect that in the act of manifestation without any observable exhaustion of the of force in a living tissue, the elements of force by which these phenomena are pro- the food are made to combine in a new duced; but the origin of the continued mani- order;-it is quite certain that the momenfestation of activity remains still the same; turn of force or of motion in' the vital force it is the abs'ence of an opposite force (a re- was more powerful than the chemical" atsistance) capable of neutralizing it or bring- traction existing between the elements of the ing it into the state of equilibrium. food.* As the manifestations of chemical forces (thei momentum of force in a chemical * Tle hands of a man, who raises with a rope 64 ANIMAL CHEMISTRY. The chemical force which kept the ele- of the buds, of the radical fibres, of the leaf, ments together acted as a resistance, which of the flower, and of the fruit, are very difwas overcome by the active vital force. ferent one from the other; and the chemical Had both forces been equal, no kind of force by which their elements are held togesensible effect would have ensued. Had the ther is very different in each of these cases. chemical force been the stronger, the living Of the non-azotized constituents of plants part would have undergone a change. we may assert, that no part, of the momenIf we now suppose that a certain amount' tum of force is expended in maintaining of vital force must have been expended in their form and structure, when their elebringing to' an equilibrium the chemical ments have once combined in that order in force, there must still remain an excess of which they become parts of organs endued force, by which the decomposition was ef- with vitality. fected.'This excess constitutes the mo- Very different is the character of the azomentum -of force in the living part, by tized vegetable principles; for, when sepameans of which the change was produced; rated from the plant, they pass, as is comnby means of this excess the part acquires a monly said, spontaneously, into fermentation permanent power of causing further decom- and putrefaction. The cause of this depositions, and of retaining'its condition, composition or transformation of their eleform, and structure, in opposition to exter- ments is, the -chemical action which -the nal agencies. oxygen of the atmosphere exercises on one'We may imagine this excess to be re- of their constituents. Now we know, that moved, and employed- in some other form. as long as the plant exhibits the phenomena This would not of itself endanger the exist- of life, oxygen gas is given off from its surence of the living part, because the.opposing face; that this oxygen is altogether without forces would be left in equilibrio; but, by action on the constituents of the living plant, the removal of the. excess of force, the part for which, in other circumstances, it has the would lose its capacity of growth, its power strongest attraction. It is obvious, thereto cause further decompositions', and its fore, that a certain amount of vital force ability to resist external causes of change. must be expended, partly to retain the eleIf, in this state of equilibrium, oxygen (a ments of the complex azotized principles in chemical agent) should be brought in con- the form, order, and structure which belong tact with it, then there would be no resist- to them; and partly as a means of resistance ance to the tendtency of the oxygen to com- against the incessant tendency of the oxygen bine with some element of the living part, of the atmosphere to act on their elements, because its power of resistance has been as well as'against that of the oxygen setaken away by some other application of its parated in the organism of the plant by the excess of vital force. According to the vital process. amount of oxygen brought to it, a certain With the increase of these easily altered proportion of the living part would lose its compounds, in the flower and in the fruit, condition of vitality, and take the foim, of a for example, the sum of chemical force (the chemical combination, having a composi- free manifestation of which, counteracted by tion different from that of the living tissue. an equal measure of vital force, is employed In a word, there would occur a change in to furnish'resistance) also increases. the properties of the living compound, or The plant increases in mass, until the vital what we have called a change of matter. force' inherent in it conies into equilibrium If we reflect that the capacity of growth with all the other causes opposed to its or increase of mass in plants is almost un- manifestation. From this period, every new limited; that a hundred twigs from a willow cause of disturbance, added to those pretree, if placed in the soil, become a hundred viously existing (a change of temperature, trees; we can hardly entertain a doubt, that for example,) deprives it of the power of of with the combination of the elements of the fering resistance, and it dies down. food of the plant so as to form a part of it, In perennial plants (in trees, for example,) a fresh momentum of force is added in the the mass of the eas:iy decomposable (azonewly formed part to the previously existing tized) compounds, compared with"'that of momentum in the plant; insomuch, that' the non-azotized, is so small, that of the with the increase of mass, the sunm of vital whole sum of force, only a minimum is force is augmented. expended-as resistance. In animals, this According to the amount of available vital proportion is reversed. force, the products formed by its activity During every period of the life of a plant, from the food are varied. The composition the available vital force (that which is not neutralized by resistance) is expended only in one form of vital manifestation, that of and simple pulley, 30 lbs. to the height of 100 growth or increase of mass, or the overfeet, pass' over a space of 100 feet, while his mus- comingof resistance. No part of this force cular energy furnishes the equilibrium to a pres- is applied to other purposes. sure of 30 lbs.. Were the force which the man In the animal organism, the vital force could exert not greater than would suffice to keep ehibits itself, n the plant, in the for in equilibrium a pressure of 30 lbs., he would- be unable to raise the weight -to the height men- of the capacity of growth, and as the means.ioned. of resistance to external agencies; but both MOTION IN THE ANIMAL ORGANISM. 65 of these manifestations are confined within means of it to decompose compounds, the certain limits. elements of which have the stronoest atWe observe in animals, that the conver- traction' for each other. Yet the substance sion of food into blood, and the contact of of the wire takes not the smallest share in the blood with the living tissues, are deter- all these manifestations of force; it is rmined by a mechanical force, whose mani- merely the conductor of force. festation proceeds from distinct organs, and We observe, further, in this wire, pheis effected by a distinct system of organs, nomena of attraction and repulsion, which possessing the property of communicating we must ascribe to the disturbance of the and extending the motion which they re- equilibrium in the electric or magnetic ceive. Wite find the power of the animal to force; and when this equilibrium is restored, change its place and to produce mechanical the restoration is accompanied by the deeffects by means of its limbs, dependent on velopement of light and heat, its never-faila second similar system of organs or appa- ing companions. ratus. Both of these systems of apparatus, All these remarkable phenomena are proas well as the phenomena of motion pro- duced by the chemical action which the ceeding from them, are wanting in plants. zinc and the acid exert on each other; they In order to form a clear conception of the are accompanied by a: change in form andi origin and source of the mechanical mo- structure, which both undergo. tions in the animal body, it may be advan- The acid loses its chemical character; the tageou-s to reflect on the modus operandi of zinc enters into combination with it. The other forces, which in their manifestations manifestations of force produced in the wire are most closely allied to the vital force. are the immediate consequence of the When a number of plates of zinc and change in the properties of the acid and the copper, arranged in' a' certain order, are metal. brought into contact with an acid, and when One particle of acid after another loses its the extremities of the apparatus are joined peculiar chemical character; and we perby means of a metallic wire, a chemical ac- ceive that in the same proportion the wire tion begins at the surface of the plates of acquires a chemical; mechanical, galvanic, zinc, and the wire, in consequence of this or magnetic force, whatever name be given action, acquires the most singular and won- to it. According to the number of acid derful properties. particles which in a given time undergo The — wire appears as the carrier or con- this change, that is, according to the surductor of a force, which may be conducted face of the zinc, the wire receives a greater and communicated through it in every di- or less amount of these forces. rection with amazing velocity. It is the The continuance of the current of force conductor or propagator of an uninterrupted depends on the duration of the chemical acseries of manifestations of activity. tion; and the duration of the latter is most Such a- propagation of motion is incon- closely connected with the carrying away, ceivable. if in the wire there were a resist- by conduction, of the fchYce. ance to be overcome; for every resistance If we check the propagation of the curwould convert a part of the moving force rent of force, the acid retains its chemical into a force at rest.- character. If we employ it to overcome When the wire is divided in the middle, chemical or mechanical resistance, to deand its continuity interrupted, the propaga- compose chemical compounds, or to protion of force ceases, and we observe, that in duce motion, the chemical action continues; this case the action between the zinc and that is to say, one particle of acid after the acid is immediately stopped. another changes its properties. If the communication be restored, the ac- In the preceding paragraphs we have tion which had disappeared reappears with considered these remarkable phenomena in all its original energy. a form which is independent of the explana-' By means of the force present in the tions of the schools. Is the force which wire, we can produce the nmost varied ef- circulates in the wire the electrical force? fects; we can overcome all kinds of resist- Is it chemical affinity? Is it propagated in ance, raise weights, set ships in motion, &c. the conductor like a fluid set in motion, or And, what is still more remarkable, the in the form of a series of momenta of mowire acts as a hollow tube, in which a cur- tion, likelight and sound, from one particle rent of chemical force circulates freely and of the conductor to another? All this we'without hindrance. know not, and, we shall never know. All Tho'se properties which, when firmly at- the suppositions which may be employed tached to certain bodies,we call the strongest as explanations of the phenomena have not and most energetic affinities, we find, to all the slightest influence on the truth of these appearance, free and'uncombined in the phenomena; for they refer merely to the wire. We can transport them from the form in which they are-manifested. wire to other bodies, and thereby give to On some points, however, there is no them an affinity (a power of entering into doubt; namely, that all the effects which combination) which in themselves they do may be produced by the wire are deternot possess. According to the amount of mined by the change of properties in the force circulating in the wire, we are able by zinc and in the acid; for the term "chemiF. bb' AS IMAL CHEMISTRY. cal action'" signifies neither more nor less tion of the muscular fibre-(just as the acid than the act of change in them; that these lost its chemical character by combining effects depend on the presence' of a'conduc- with zinc;) and all experience'proves, that tor, of a substance which propagates in all this conversion of' living muscular fibre into directions, where it is not neutralized by re- compounds destitute of vitality is accelerated sistance, the force or momentum produced; or retarded according to the amount of force that this force becomes a momentum of employed to produce motion. Nay, it may motion, by means of which we can produce safely be affirmed, that they are mutually mechanical effects, and which, when trans- proportional; that a rapid transformation of ferred to other bodies, communicates to muscular fibre,' or, as it may be called, a them all. those properties, the ultimate cause rapid change of matter, determines a greater of which is the chemical force itself; for amount of mechanical force; and conthese bodies acquire the power of causing versely, that a greater amount of medecompositions and combinations, such as, chanical motion (of mechanical force exvwithout a supply of force throughthe con- pended in motion) determines a more rapid ductor, they could not effect. change of matter. If we employ these well known facts as From this decided relation between the means. to assist'us in investigating the ulti- change of matter in the animal body and the mate cause of'the mechanical effects in the force consumed in mechanical motion, no animal organism, observation teaches us, other conclusion can be drawn but this, that that the motion of the blood and of the other the active or available vital force in certain animal fluids proceeds from distinct organs living parts is the cause of the mechanical which, as in the case of the heart and in- phenomena in the animal organism. testines, do not generate the moving power The moving force certainly proceeds from -in themselves, but receive. it from other living parts; these parts possessed a moquarters..' mentum of force or of motion, which they We know with certainty that'the' —nerves lost in proportion as other parts acquired are the conductors and propagators of me- a momentum of force or of motion; they chanical effects; we know, that by means of lose their capacity of growth, and their them motion is propagated in al'ldirections. power to resist external causes of change. For each motion we recognize a separate It is obvious that the ultimate cause, the nerve, a peculiar conductor, with the con- vital force, from which they acquired these ducting power of which, or with its inter- properties, has served for the production of ruption, the propagation of motion'is affected mechanical force, that is, has been expended or destroyed,' in the shape of motioni. By, means of the nerves all parts of the How, indeed, could we conceive that a body, all the limbs,'receive the moving force living part should lose the condition of life, which is indispensable to their functions, to should become incapable of resisting the change of place, to the production o f me- action of the oxygen conveyed to it by the chanical effects. Where nerves. are not arterial blood, and should be deprived of the found, motion does not occur. The excess power to overcome chemical resistance, of force generated in one place is conducted unless the momentum of the vital force,'to other parts by -the nerves. The force which had given to it all these properties, which one organ cannot produce in itself is had been expended for other purposes? -conveyed to it from other quarters; and the' By the power of the conductors, the vital force which is wanting to it, in order nerves to propagate the momentum of force'to furnish resistance to external causes of in a living part, or the effect which the disturbance, it receives in the form of excess active vital force inherent in the part' pro. from another organ, an excess which that duces on all the surrounding parts,.in all organ -cannot consume in itself. directions where the force, or rather its moWe observe further, that the voluntary mentum of motion, is consumed without and involuntary motions, in other words, all resistance, (for without motion no change mechanical effects in the animal organism,, of mnitte.r occurs, and when motion has are accompanied by, nay, are dependent on, begun, there is no longer'resistance,) an a peculiar change of form'and structure in equilibrium is obviously established in the the substance of certain living parts, the in- living part, between the chemical forces and crease or diminution of which change stands the remaining vital force; which equilibrium in the very closest relation to the measure of would not have occurred had not vital motion, or the amount of force consumed force been expended in producing mein the motions performed.' chanical motion. As an immediate effect of the manifesta- In this state, any external cause capable tion of mechanical force, we see, that a part of exerting an influence on the form, strucof the muscular substance loses its'vital ture and composition of the organ meets properties,'its' character of life; that this with no further resistance. If oxygen were portion separates from the living part, and not conveyed to it, the organ'would mainloses its capacity of growth and its power of tain its condition- but without,any maniresistance. We find that this change of Gestation of vitality. It is only with the properties is accompanied by the entrance commencement of chemical action'that'the of a foreign body (oxygea) into the com~pai- change of matter, that is, the separation of MOTION IN THE ANIMAL ORGANISM. 67. a part of the organ in the form of lifeless The substance of cellular tissue, of memcompounds, begins. branes,. and of the slin, the minutest partiThe change of matter, the manfestation cles of which are not in immediate contact of mechanical force, and the absorption of with arterial blood, (vwith oxygen,) are not oxygen, are, in the animal body, so closely destined to undergo this -change of matter. connected with each other, that we may Whatever, changes'they may undergo' in consider the amount of motion, and the the vital process, affect, in all cases, only quantity of living tissue transformed, as pro- their surface. portional to the' quantity of oxygen inspired The gelatinous tissues, mucous mernand consumed in \a given tinme by the branes, tendons,'&c., are not designed, to animal. For a certain amount of motion, produce mechanical force; they contain in for a certain proportion of vital force con- their substance no conductors of mechanical sumed- as mechanical force, an equivalent effects. But the muscular system is interof chemical force is manifested; that. is, an woven with innumerable nerves. The sub — equivalent of oxygen enters into combina- stance of the uterus is in no respect different tion with the substance of the organ which in chemical composition from the other mushas lost the vital force; and a corresponding cles; but it is not adapted to the change of proportion' of the substance of the organ is' matter, to the production of force, and conseparated from the living tissue in the shape tains no organs for conducting away the of an oxidized compound. moving power. Cellular tissue, gelatinous All those parts of' the body which nature membranes, and' mucous membranes, are has destined to effect the change of matter, far from'being destitute of the power of that is, to the production of mechanical force, combining with oxygen, when moisture is are penetrated in all directions by a' multi- present; we know that, when moist, they tude of the most minute tubes or vessels, in cannot be'brought in contact with oxygen Which a current of oxygen continually cir- without undergoing a progressive alteration. culates, in the form of arterial- blood. To But one surface of the intestines and the the above-mentioned separation of'part of cells of the lungs are constantly in contact the elements of these parts, in other Words, with oxygen and it is obvious that they to the disturbance of their equilibrium,. this must be as rapidly altered by the chemical oxygen is absolutely' essential. action of the oxygen in the body as out of As long as the vital force of these parts it, were it not that there exists in the oris not conducted away and applied to other ganism itself a source of resistance, which purposes, the oxygen of the arterial blood completely neutralizes the action of the oxyhas not the slightest effect on the substance gen. Among the means by which this reof the organized parts; and in all cases, sistance is furnished we may include all only so much oxygen, is taken up as cor- substances which are capable of combining responds to th-e conducting power, and, con- with oxygen, or acquire that property under sequently to the mechanical efects produced. the influence of the vital force, and which The oxygen of the atmosphere is the. surpass the tissues above mentionedin their proper, active, external cause of the waste power of neutralizing its chemical action. of matter in the animal body: it acts like a All those constituents of the body which, force which disturbs and tends to destroy in themselves, do not possess, in the form the manifestation of the vital force at every of vital force, the power of resisting the moment. But its effect as a chemical agent, action of oxygen, must be far. better adapted the disturbance proceeding from it, is'held for the purpose of combining with, and in equilibrium by the vital force, which is neutralizing it, than those tissues which are free and available in the living tissue, or is under the influercee of the vital force, aiannihilated by'a chemical agency opposed though only through the nerves. In this to that of oxygen, the man.ifestation of point of viewv, we cannot fail to perceive which must be considered as dependent on the importance of the bile in regard' to the the vital force. substance of the intestines, and that of the In chemical language, to annihilate the pulmonary cells, as well as that of fat, of chemical action' of oxygen, means, to pre- mucus, and of the secretions generally. sent to it substances, or parts of organs, When the membranes are compelled from which are capable of combining with it. their own substance to furnish resistance to The action of oxygen (affinity) is either the action of the oxygen, thatis, when there neutralized by' means of the elements of is a deficiency of the substances destined'by organized parts, which combine with it, nature for their protection, they must, since (after the free vital force has been conducted -their renewal is'confined within narrow away,) or else the organ presents to it the limits, yield to the chemical action.'The products of other organs, or certain matters lungs and intestines will always simultaformed from the elements of the food, by neously suffer abormal changes. the vital activity of certain systems of ap- From the change of matter itself, from paratus. the metamorphosis of'the living niuscular It is.olnly the muscular system which, in tissue, these organs receive the means of this'sense, produces in itself a resistance to I'resistance to the action of oxygen which are the chemical action of oxygen, and neutral- indispensable to their preservation. Accordizes it completely. ing to the rapidity of this process, the quan 68 ~ANIMAL CHEMISTRY. tity of bit e secreted increases; while that of prived of its vital force, cannot be in the the fat present in the body diminishes in the slightest degree affected by the consumption same proportion. - of the vital force of another part in producing For carrying on, the involuntary motions motion. The one may increase in Volume, in the -animal body, a certain amount of vital while the other diminishes; and the waste force Jis expended at every moment of its in one can neither increase nor diminish the existence; and, consequently, an incessant supply in the other. change of matter goes on; but the amount Now, since the consumption of force for of living tissue, which, in consequence of the involuntary motions continues in sleep, this form of consumption of vital force, it is plain that a waste of matter also conloses its condition of life and its oapacity of tinues in that state; and if the originalequigrowth, is confined within narrow limits. librium is to be restored, we must suppose It is directly proportional to the force re- that, during sleep, an amount of force is ac-quired for these involuntary motions. cumulated in the form of living tissue, Now, although we may suppose, that the exactly equal-to that which was consumed living muscular tissue, with a sufficient sup- in voluntary and, involuntary motion during ply of food, never loses its capacity of the preceding waking period. growth; that this form of vital manifestation If the equilibrium between waste and is continually effective; this cannot apply to supply of matter be, in the least degree disthose parts of the body whose available vital' turbed, this is instantly seen in the different force has been expended in producing me- amount of force available for mechanical chanical effects. For the waste of matter, purposes. in consequence of motion and laborious. It is further obvious, that if there should exertion, is extremely various in different occur a disproportion between the conductindividuals. ing power of the nerves of voluntary and If we reflect, that the slightest motion of involuntary motion, a difference in the phea finger consumes force; that in conse- nomena of motion themselves will be perquence of the force expended, a correspond- ceptible,' in the'same proportion as the one ing portion of muscle diminishes in volume; or the other is capable of propagating the it is obvirz!s, that an equilibrizm between momentum offorce, generated by the change supply and waste of matter (in living tissues) of matter. As the motions of the circulating can only occur when the portion separated system and of the intestines increase, the or expelled in a lifeless form is, at the same power of producing mechanical' effects in instant in which it loses its vital condition, the limbs must diminish in the same proporrestored in another part. tion (as in wasting fevers;) and it, in a given The capacity of growth or increase in time, more vital force has been ronsumed mass depends on: the momentum of force for mechanical purposes (labour, running, belonging to each part; and must be capable dancing, &c.,) than is properly available for of continued manifestation (if there be a suf- the voluntary and involuntary motions; if ficient supply of nourishment,) as long as it force be expended more rapidly thin the does not lose this momentum, by expending change of matter can be effected in the same it, for exampie, in producing motion. time; then, a part of that force which is In all circumstances, the growth itself is necessary for the involuntary motions must restricted to the time: that is to say, it can- be expended in restoring the excess of force not be unlimited in a limited time. consumed in voluntary motion. The moA living part cannot increase in volume tions of the heart and of the intestines, in at the same moment in which a portion of this case, will be retarded, or will entirely it loses the vital condition, and is expelled cease. from the organ in the form of a lifeless com- From the unequal degree of conducting pound; on the contrary', its volume must power in the nerves, we must deduce those diminish. conditions which are termed paralysis, synThe continued application of the momen- cope, and spasm. Paralysis of the nerves tum of force in living tissues to mechanical of voluntary motion may exist without emnaeffects determines, therefore, a continued ciation; but frequently recurring attacks of separation of matter; and only from the pe- epilepsy (in which vital force is rapidly riod at which the cause of waste ceases to wasted in producing mechanical effects) are operate, can the capacity of growth be ma- always accompanied by remarkably rapid nifested. emaciation. Now, since, in different individuals, ac- It ought to excite the highest admiration cording to the amount of force consumed in- when we consider with what infinite wisproducing voluntary mechanical effects, un- dom the Creator has divided the means by equal quantities of living tissue are wasted, which animals and plants are qualified for there must occur, in every individual, unless their functions, for their peculiar vital manithe phenomena of motion are to cease en- festations. tirely, a condition in which all voluntary The living part' of a plant requires the motions are completely checked, in which, whole force and direction of its vital energy therefore, these occasion no waste. T'lis from the absence of all conductors of force. condition is called sleep. By this means the leaf is enabled to overThe growth of one part, which is not de- come the strongest chemical attractions, to MOTION OF ANIMAL ORGANISM. 69 eceompose carbonic acid, and to assimilate So is it with the vital force, and with the the elements of its nourishment. phenomena exhibited by living bodies. The In the flower alone does arprocess similar cause of these phenomena is not chemical to the change of matter in the aninal body force; it is not electricity, nor magnetism; occur. There, phenomena of motion ap- itis a force which has certain properties in pear-; but the mechanical effects are not common with all causes of motion and of propagated to a distance, owing to the ab- change in form and structure in material sence of' conductors of force. substances. It is a peculiar force, because The same vital force which we recognize it exhibits manifestations which are found in in the plant as an almost unlimited capacity no other known force. of growth, is converted in the animal body II. In the livin- plant, the intensity of the into moving power (into a current of vital vital force far exceeds that of the chemical force;) and a most Wonderful and wise ecb- action of oxygen. nomy has destined for the nourishment of We know, with the utmost certainty, that the animal only such compounds as have a by the influence of the vital force, oxygen is composition identical with that of the organs separated from elements to which it has the which generate force, that is, with the mus- strongest affinity; that it is given out in the cular tissue. The expenditure of force gaseous form, without exerting the slightest which the living parts of animals require, action on the juices of the plant. in order to reproduce themselves from the How powerful, indeed, must the resistance blood; the resistance of the chemical force appear which the vital force supplies to which has to be overcome in the azotized leaves charged with oil of turpentine or tanconstituents of food by the vital agency of nic acid, when we consider the affinity of the organs destined to convert them into oxygen for these compounds! blood; these are as nothing compared to This intensity of action or of resistance the force with which the elements of carbo- the plant obtains by means of the sun's nic acid are held together. A certain amount light; the effect of which in chemical acof force would necessarily be prevented from tions may-be, and is, compared to that of a assuming the form of moving power, if it very high temperature (moderate red heat.) were to be expended in overcoming chemical During the night an opposite process goes resistance; for the momentum of motion of on in the plant; we. see then that the conthe vital force is diminished by all obstacles. stituents of the leaves and green parts comBut the conversion of the constituents of bine with the oxygen of the air, a property blood into muscular fibre (into an organ which in daylight they did not possess. which generates force) is only a change of From these facts we can draw no other form. Both have the same composition; conclusion but this: that the intensity of the blood is fluid, muscular fibre is solid blood. vital force diminishes with the abstraction We may even suppose that this change of light; that with the approach of night a takes place without any expenditure of vital state of equilibrium is established, and that force; for the mere passage of a fluid body in complete darkness all.those constituents into the solid state requires no manifestation of plants which, during the day, possessed of force, but only the removal of obstacles, the power of.separating oxygen from chemrniwhich oppose that force (cohesion) which cal combinations, and of resisting its action determines the form of matter, in its mani- lose their power completely. Gestations. A precisely similar phenomenon is obIn what form or inr what manner the vital served in animals. force produces mechanical effects in the ani- The living animal body exhibits its pecumal body is altogether unknown, and is as liar manifestations of vitality only at certain little to be ascertained by experiment as the temperatures. When exposed to a certain connexion of chemical action with the phe- degree of cold, these vital phenomena ennomena f. motion which we can produce tirely cease. with the galvanic battery.' All the explana- The abstraction of heat must, therefore, tions which have been attempted are only be viewed as quite equivalent to a diminurepresentations- of the phenomenon; they tion of the vital energy; the resistance op are, more or less, exact descriptions and posed by the vital force to external causes of comparisons of known phenomena with disturbance must diminish, in certain tempethese, whose causeis unknown. In this re- ratures, in the same matio in -which the spect we are like an ignorant man, to whom tendency of the elements of the body, to the rise and fall of an iron rod in a cylinder,'combine with the oxygen of the air inin which the eye can perceive nothing, and creases. its connexion with the turning and motion By the combination of oxygen with the of a thousand wheels at a distance from the constituents of the metamorphosed tissues, piston-rod, appear incomprehensible.. the temperature-necessary to the manifestaWe know not how a certain something, in- tions ofi vitality is produced in the carnivora. visible and imponderable in itself (heat) gives In the herbivora, again, a certain amount of to certain bodies the power of exerting an -heat is developed by means of those elements enormous pressure on surrounding objects; of their -non-azotized food which have the we know not even how this something it- property of combining with oxygen. self is produced when we burn wood or coals. It is obvious that the temperature of an 70 ANIMAL CHEMISTRY. animal body.cannot change, if the amount temperature of the body sinks, the power of of inspired oxygen increases, in the same, the limbs to produce mechanical effects (or ratio as the loss of heat by external cooling. the force necessary to the-voluntary motions),Two individuals,, carnivora, of equal i s also diminished. The condition of sleep weight, exposedto unequal degrees of cold, ensues, and at last even the involuntary lose, in a given time, by external cooling, motions (those of the heart and intestines, unequal quantities of heat. Experience for example) cease, and apparent death or teaches, that if their peculiar temperature syncope supervenes. and their original weight are to remain un- It is obvious that the causeof the generaaltered, they require unequal quantities of tion of force, namely, the change of matter, food; more in the lower temperature than is diminished, because, with'the abstraction in the highe'r.'of heat, as in the plant by abstraction of The circumstance that the original weight light, the intensity of the vital force diremains the same, with- unequal quantities minishes. It is also obvious that the moof food, obviously presupposes, that in the mentum of force in a living. part depends same time a quantity of oxygen proportioned on its proper temperature; exactly as the to the temperature has been absorbed; more effect of a falling body stands in a fixed in the lower than in the higher temperature. relation to certain other conditions; for exWe find that the weight of both indi'vi- ample, to the velocity attained in falling. duals, at the end of 24 hours, is equal to the When the temperature sinks, the vital original, weight. But we have'assumed energy diminishes; when.it again rises, the that.their food is. converted into blood; that momentum of force in the living parts'the blood has served for nutrition; and it is appears once more in all its original inplain, that when the original weight has tensity. been restored, a quantity of the constituents. The production of force for mechanical of the body, equal'in-weight to. those of the purposes, and the temperature of the body, food, has lost its condition of life, and has must, consequently, bear a' fixed relation to been expelled in combination with oxygen. the amount of oxygen which can be absorbed The one individual, which, being exposed in a given time by the anrimal body. to the lower' temperature, consumed more The quantities of oxygen which a whale food, has also absorbed more oxygen; a and a carrier's horse can inspire in a given greater quantity'of the. constituents of its time are very unequal. The temperature, body has been separated.in combination as well as the quantity'of oxygen, is much with oxygen.; and, in consequence of this greater in the horse.. combination with oxygen, a greater amount The force exerted by a whale, when of heat has been liberated, by which means struck with the' harpoon, his body being the heat abstracted. has been restored, and supported by the surrounding medium, and the proper temperature of the body kept up. the force exerted by a carrier's horse, which Consequently, by the abstraction of heat, carries its own weight and a heavy burden provided there be a full supply of food.and for eight or ten hours, must both'bear the free access of oxygen, the chance of matter same ratio to the oxygen consumed. If we must be accelerated; and, along with the take into consideration the time during which augmented transformnation, in a given time, the force is manifested, it is obvious that the of living tissues, a greater amount of vital amount of force developed by the horse is force must be r'endered available for mecha- far greater than in the case of the whale. nical purposes. In climbing high mountains, where, in'With the external cooling, the respiratory consequence of the respiration of a highly motions become stronger; in a lower tem- rarefied atmosphere, much less oxygen is perature more. oxygen is conveyed to the conveyed to the blood, in equal times, than'blood; the waste of matter increases, and if in valleys or at the level of the sea, the the supply be not'.kept in equilibrium with change of matter diminishes in the same this waste, by means of food, the tempera- ratio, and with it the amount of force availture of the body gradually sinks. able for mechanical purposes. For the mosi But, in a given time, an unlimited supply part, drowsiness and want'of force for me-, of oxygen cannot be introduced into.the chanical exertions come on; after twenty or body; only a certain amount of living tissue thirty steps, fatigue compels us to a fresh can lose.the state of life, and only a. limited accumulation of.force by means of rest (abamount of vital;.force' can be manifested in sorption of oxygen without waste of force mechanical phenomena. It is only, there- in voluntary motions.) fore, when the cooling, the generation of. By the absorption of oxygen into the subforce, and the absorption of oxygen are in stance of living tissues, these lose their conequilibriumr together, that the temperature dition of life, and are separated as lifeless, of the body can remain unchanged. If the unorganized compounds; but the whole of loss of heat by cooling go beyond a certain the inspired oxygen is not applied to these point, the'vital phenomena diminish in the transformations: the greater part serves to same ratio; for the temperature falls, and conv'ert into gas and vapour all matters the temperature must be considered as a which no longer belong to the organism; uniform condition of their manifestation. and, as formerly mentioned, the combinaNow experience teaches, that when the tion of the elements.of sucli compounds MOTION IN THE ANIMAL ORGANISM. 71 with the oxygen produces the temperature motion, and conveyed to the heart, lungs, proper to the animal organism. and intestines. In this case, the circulation The production of heat and the change will appear accelerated at the expense of of matter are closely related to each other: the force available for voluntary motion; but although heat can be produced in the but, as was before remarked, without the body without any change of matter in living production of a greater amount of mechanitissues, yet the change of matter cannot be' cal force by the process of oxidation of the supposed to take place without the co-opera- alcohol.', tion of oxygen. Finally, we observe, in hybernating aniAccording to all the observations hitherto mals, that, (luring their winter sleep, the made,. neither the expired air' nor the per- capacity of increase in mass (one of the spiration, nbr the urine, contains any trace chief manifestations of the vital force,) of alcohol, after indulgence in spirituous owing to the absence of food, is entirely liquors; and there can be no doubt that the suppressed. In several, apparent death ocelements of alcohol combine with. oxygen curs in consequence of the low temperature in the body; that its carbon and hydrogen and of the diminution of vital energy thus are gi-ven off as carbonic acid and water. produced; in. others, the involuntary mnoThe oxygen which has accomplished this tions continue, and the animal preserves a change must have been. taken from the arte- temperature independent of the surrounding rial blood; for we' know of no channel, temperature. The respirations go on; oxysave the circulation' of the'blood, by which gen, the condition which determines the oxygen can penetrate into the interior of the production of heat and force, is absorbed body. now as well as in the former state of the Owing to its volatility, and the ease with animal';' and previous to the winter sleep, which its vapour permeates animal mem- we find all those parts of their body, which branes and tissues, alcohol can. spread in themselves are unable to furnish resistthroughout the body in all~directions. ance to the action of the oxygen,. and which, If the power of the elements of alcohol like the intestines and membranes, are not to combine with oxygen were not greater destined for the change of matter, covered than that of the compounds formed by the with fat; that is, surrounded by a substance change of matter, or that of the substance which' supplies the want of, resistance. of living tissues, they (the elements of alco- If we now suppose, that the oxygen abhol) could not combine with oxygen in the sorbed during the winter sleep.,combines,' body.' not with the elements of-living tissues, but It is, consequently,.obvious, that by the with those of the fat, then the living part, use of alcohol a limit must rapidly be put although a certain momentum of motion be to the change of matter in certain'parts of expended in keeping up the circulation, will the body. The'oxygen of the arterial not be separated and expelled from the body. blood, which, in the absence of alcohol,'With the return of the higher tempera-' would have combined with the matter of ture- the capacity of growth increases in the the tissues,.or with that formed by the meta- same ratio, and the motion of the blood inmorphosis of these tissues, now combines creases with the absorption'of.oxygen. with the elements of alcohol. The arterial Many of these animals become emaciated blood becomes venous, without the substance during the winter sleep, others not till after of the muscles having taken any share in awaking from it. the transformation. In hybernating animals the active force Now we observe, that the' developement of the living'parts is exclusively devoted, of heat in the body, after the use of wine, during hybernation, to the support of the inincreases rather than diminishes, without voluntary motions. The expenditure of force the manifestation of a corresponding amount in voluntary motion is entirely suppressed. of mechanical force. In contradistinction to these phenomena, A.moderate quantity of wine, in women we know that, in the case of excess of moand children unaccustomed to its use, pro- tion and exertion, the' active force in living duces, on the contrary, a diminution of the parts may be exclusively and' entirely conforce necessary for voluntary motions. sumed in producing voluntary mechanical Weariness, feebleness in the limbs, and' effects; in such wise that no force shall redrowsiness, plainly show that the force main available for the involuntary motions. available. for mechanical purposes, in other A stag may be hunted to death; but this words, the change of matter, has been di- cannot occur without the metamorphosis of minished. - all the living parts of its muscular system, A diminution of the conducting power and its flesh becomes uneatable. The conof the nerves of voluntary motion may dition of metamorphosis into which it has doubtless take a certain share in producing been brought by an enormous consumption these symptoms;'but this must be alto- both of force and of oxygen continues when gether without influence on the sum of all phenomena of motion have ceased. In available force'.' " the living tissues, all the resistance offered. What the conductors of voluntary motion by the vital force to external agencies of cannot carry away for effects of tforce, must change is entirely destroyed. be taken up by the nerves of involuntary But however closely the conditions of the 72 ANIMAL CHEMISTRY. production of heat and of force may-seem body as have an affinity for it, "time is reto be connected together, with reference to quired. mechanical effects, yet the disengagement In a given time, only a limited amount of of heat can in no way be considered as in mechanical force can be manifested, and itself. the only cause of these effects. only a limited amount of heat can be libeAll'experience proves, that there is, in rated. the organism, only one source of mechani- That which is expended, in' mechanical cal power;-and this source is the conversion effects, in the shape of velocity, is lost in of living parts into lifeless, amorphous com- time; that is to say, the more rapid the mopounds. tions are, the sooner or the more quickly is Proceeding from this truth, which is inde- the force exhausted. pendent of all theory, animal life may be The sum of the'mechanical force proTiewed as determined by the mutual action duced in a given time is equal to the sum of of opposed forces; of which one class must force necessary, during the same time, to Je considered as causes of increase, (of sup- produce the voluntary and involuntary moply of matter,) and the other as causes of tions; that is, all the force which the heart, Jiminution (of waste of matter.) intestines, &c., require for their motions is The increase of mass is effected in living lost to the voluntary motions. Darts by' the vital force; the manifestation The amount of azotized food necessary to -f this power is dependent on heat; that is, restore the equilibrium between waste and -:n a certain temperature peculiar to each supply is directly proportional to the amount specific organism.. of tissues metamorphosed. The cause of waste of matter is the chemi- The amount of living matter, which in Cal action of oxygen; and its manifestation the body loses the'condition of life, is, in is dependent on the abstraction of h'eat as equal temperatures, directly proportional to well as on the expenditure of the vital force the mechanical effects produced - in a given;or mechanical purposes. time., The act of waste of matter is called the The amount of' tissue metamorphosed in change of matter; it occurs in consequence a given time may be measured by the quanof the absorption of oxygen.into the sub- tity of nitrogen in the urine. stance of living parts. This absorption of The sum of the mechanical effects prooxygen- occurs only when the resistance deuced in two individuals, in the same tem., which the vital force of the living parts op- perature, is proportional to the -amount of poses to the chemical action of the oxygen nitrogen in their urine; whether the mrechais weaker than that chemical action; and'nical force has been employed in voluntary this weaker resistance is determined by the or involuntary motions, Whether it has been abstraction of heat, or by the expenditure in' consumed by the limbs or by the heart and mechanical motions of.the available force' other viscera. of living parts. That condition of the body which is called By, the combination of the oxygen intro- health includes the conception of an equiliduced into the arterial blood with such con- brium among all the causes of waste and stituents of the body as offer no resistance of supply; and thus animal life is recogto its action, the temperature necessary for nized as the mutual action of both; and apthe manifestation of vital activity is pro- pears as an alternating destruction and restoduced. ration of the state of equilibrium. From the relations between the consump- In regard to its absolute amount, the waste tion of oxygen on the one hand and the and supply of matter is, in the different pechange of matter and developement of heat riods of life, unequal; but, in the state of on the other, the following general rules may health, the available vital force must always be deduced. be considered as a constant quantity, correFor every proportion'of oxygen which sponding to the sum of living particles. enters into combination in the body, a cor- Growth, or the increase of mass, stands, responding proportion of heat must be gene- at every age, in a fixed relation to the rated. amount of vital force consumed as moving The sum of force available for mechanical power. purposes must be equal to the sum of vital The vital force, which is expended for forces of all tissues adapted to the change mechanical purposes, is subtracted from the of matter. sum of the force available for the purpose If, in equal times, unequal quantities of of increase of mass. oxygen are consumed, the result is obvious, The active force, which is consumed in in an unequal amount of heat liberated, and the body in overcoming resistance (in causof mechanical force. ing increase of mass) cannot, at the same When unequal amounts'of mechanical time, be employed to produce mechanical force are expended, this determines the ab- effects. sorption of corresponding and unequal quan- Hence it follows necessarily, that when, tities of oxygen. as in childhood, the- supply exceeds the' For the conversion of living tissues into waste of matter, the mechanical effects prolifeless compounds, and for the combination duced must be less in the same proportion. of oxygen with such constituents of the' With the increase of mechanical effectc MOTION IN THE ANIMAL ORGANISM. 73 produced, the capacity of increase of mass. rectly proportional to the number of hours or of the supply of waste in living tissues of sleep. must diminish in the same proportion. The adult man sleeps 7 hours, and wakes A perfect balance between the consutip- 17 hours; consequently, if the, equilibrium tion of vital force for supply of matter and be restored in 24 hours, the mechanical efthat for mechanical effects occurs, therefore, fects produced in 17 hours must be equal to only-in the adult state. It is at once recog- the effects produced during 7 hours in thel nized in the complete supply of the matter shape of formation of new parts. consumed. In old age more is wasted; in An.old man sleeps only 3~ hours; and if childhood more is supplied than wasted. every thing else be supposed the same as in The force available for mechanical pur- the case of the adult, he will be able, at all poses in an adult man is reckoned, in iie- events, to produce half of the mechanical chanics, equal to the ith of his own weight, effects produced by-an adult of equal weight; which he can move during eight hours,. that is, he will be able to. carry only 15 lbs. with a velocity of five feet in two seconds. instead of 30 to the same distance. If the weight of a mlan be 150 lbs., his The infant at the breast sleeps 20 hours force is equal to a weight of 30. lbs. carried and wakes only four; the active force conby him to a distance of 72,000 feet. For sumed in formation of new parts is, in this every second his momentum of force is case, to that consumed in mechanical effects =30 X 25= 75 lbs.; and for tie whole (in motion of the limbs) as 20 to 4; but his day's work his momentum of motion is limbs possess no momentum of force, for he =30 X 72,000 = 216,000. cannot yet support his own body. If we By the restoration of, the original weight assume, that the aged man and infant conof his body, the man collects again a sum sume in mechanical effects a quantity of of force -which allows him, next day, to pro- force corresponding to the proportion avail duce, without exhaustion, the same amount able in the adult, then the mechanical effects of mechanical effects. are proportional to the number of waking This supply offorce isfurnished in a seven hours, the formation of new parts to the hours' sleep. number of hours of sleep, and we shall have: In man ufactories of rolled iron it fre- Force expended in Force expended in quently happens, that the pressure of the mechanical effects. formation of newparts. engine, going at its ordinary rate, is not suf- In the adult. 17: 7 ficient to force a rod of iron of a certain In theinfant.. 4: 20 thickness to pass below the cylinders. The In the old man. 20: 4 workman, in this case, allows the whole force of the steam to act on the revolving In theadult a perfect equilibrium takes wheel, and not until this has acquired a place between waste and supply; in the old great velocity does he bring' the -rod under man and in the infant, waste and supply are the rollers; when it is instantly flattened with not in equilibrium. If we make the congreat ease into a plate, while the wheel gra- sumption of force in the 17 waking hours dually loses the velocity it had acquired. equal to that required for the restoration of What the wheel gained in velocity the roller the equilibrium during sleep = 100 -17 gained in force; by this process force was waking hours — 7hours of sleep, weobtain obviously collected, accumulated in the e- the following proportions. The mechanical locity; but in this sense force does' not ac- effects are to those in the shape of formaton cumulate in the living organism. f new parts: The restoration of force is effected, in the In the adult man 100:100 animal body, by the transformation of the In the infant 25: 250 separated parts, destined for the production In the old man. - 125: 50 of force, and by the expenditure of the active Or the increase of mass to the diminuticn vital force in causingfor'nation of newparts; by waste: and, with the restoration of the separated or In the adult man 100: 100 effete parts, the organism recovers a force In the infant. 100: 10 equal to that which has been expended.. In the old man. 100: 250 It is plain, that the vital force manifested, It is consequently'clear, that if the old during sleep, in the formation of new parts, man performs an amount of work propormust be equal to the whole sum of the niov- tional to the sleeping hours of the adult, the ing power'expended in the waking state in waste will be greater than the supply; that all mechanical effects whatever, plus a cer- is, his body will rapidly decrease in weight, tain amount of force, which is required'for if he carry 15 lbs. to the distance of 72,000 carrying on those involuntary motions which feet with a velocity of 2- feet in the second; continue during sleep. but he will be able, without injury, to carry From day to day, the labotlring man, with 6 lbs. to the same distance. sufficient food, recovers, in seven hoursO In the infant the increase is to the decrease sleep, the whole sum of force; and without'as 10 to 1, and consequently, if we in his reckoning the force necessary for the invo- case increase the expenditure of force in luntary motions which may be considered mechanical effects to ten timesits proper equal in all men, we may assume, that the' amount, there will thus be established only mechanical force available for work is di- an equilibrium between waste and surply 10 G 74 ANIMAL CHEMISTRY. The child, indeed, will not grow, but neither an equilibrium will soon be established. The will it lose weight. piston-Jod- resists a certain force without If, in the adult man, the consumption of moving, but is raised by an increased presforce for mechanical purposes in 24 hours sure. When this excess of force has been be augmented beyond the amount restorable consumed in motion, it cannot be raised in seven hours of sleep, then, if the equili- higher; but if new vapour, be continually brium is to be restored, less force' in the admitted, the rod will continue to move. same proportion, must be expended in me- In the cooled part of the body, the living chanical effects in the next 24 hours. If tissues offer a less resistance to the chemical this be not done, the mass of the body de- action of the inspired oxygen; the power creases, and the state' characteristic of old of the oxygen to unite with the elements of age more or less decidedly supervenes. the tissues is, at this part, exalted, When With every hour of sleep the sum of avail- the part has once lost its condition- of life, able force increases in the old man, or ap- resistance entirely ceases; and in conseproaches the state of equilibrium between quence of the combination of the oxygen waste and supply which exists in the adult. with the elements of'the metamorphosed It is further evident, that if a part of the tissues, a greater amount of heat is liberated. force which is available for' mechanical For a given amount of oxygen, the heat purposes, without disturbing the equilibrium, produced is, in all cases, exactly the same. should not be consumed in moving the In the cooled part, the change of matter; limbs, in raising weights, or in other labour, and with it the disengagement of heat, init will be available for involuntary motions. creases; while in the other parts the change If the motion of the heart, of the fluids, and of matter and liberation of heat decrease. of the intestines (the circulation of the blood But when the cooled part, by the union of and digestion) are accelerated in proportion oxygen with the elements of. the metamorto the amount of force not consumed in phosed tissues, has recovered its original voluntary motions, the weight of the body temperature, the resistance of its living parwill neither increase'or diminish in 24 hours. tides to the oxygen conveyed to them again The body, therefore, can only increase in increases, and, as the resistance of other mass, if the force accumulated duringo sleep, parts is now diminished, a more rapid and available for mechanical purposes, is change of matter now occurs in them, their employed neither for voluntary nor for in- temperature rises, and along with this, if the voluntary motions. cause of the change of matter continues to The numerical values above given for operate, a larger amount of vital force bethe expenditure of force in the human body comes available for mechanical purposes. refer, as has been expressly stated, only toa Let us now suppose that heat is abstracted given, uniform temperature. In a different from the whole surface of the body; in this temperature, and with deficient nourishment, case the whole action of the oxygen will be all these proportions must be changed. directed to the skin, and in a short time the If we surround a part of the body with ice change of matter must increase throughout or snow, while other parts are left in the the body. Fat, and all such matters as are natural state, there occurs, more or less capable of combining with the oxygen quickly, in consequence of the loss of which is brought to them in larger quantity heat, an accelerated change of matter in than usual, will be expelled from the body -the cooled part. in the form of oxidized compounds. The resistance of the living tissues to the III. THEORY OF DISEASE. Every sub-;action of oxygen is weaker at the cooled stance or matter, every chemical or mechapart than in the other parts; and this, in its nical agency, which changes or disturbs the effects', is equivalent to an increase of re- restoration of the equilibrium between the sistance in these other parts. manifestations of the causes of waste and The momentum of force of the vitality in supply, in such a way as to add its' action the parts which are not cooled is expended, to the causes of waste, is called a cause of:as before, in mechanical motion; but the disease. Disease occurs when the sum of whole' action of the inspired oxygen is vital force, which tends to neutralize all'exerted on the cooled part. causes of disturbance, (in other words, when If we imagine an iron cylinder, into the resistance offered by the vital force,) is which we admit steam under a certain weaker than the acting cause of disturbance. pressure, then if the forge with which the Death is that condition in which all resistparticles of the iron cohere be equal to the ance on the part of the vital force entirely force which tends to separate them, an equi- ceases. So long as this condition is not eslibrium will result; that is, the whole effect tablished, the living tissues continue to offer of the steam will be neutralized by the re- resistance. sistance. But if one of the sides of the To the observer, the action of a cause of cylinder be moveable, a piston-rod, for ex- disease exhibits itself in the disturbance of'ample, and offer to thepressure of the steam the proportion between waste and supply a less resistance than other parts, the whole which is proper to each period of life. In force will'be expended in moving this one medicine, every abnormal condition of supside-that is, in raising the piston-rod. If ply or of waste, in all parts or in a single we do not introduce flesh steam (fresh force) part of the body, is called disease. THEORY OF DISEASE. 75 It is evident that.zle and the same cause This state is called afebrile paroxysm. Of disease will produce in the organism very In consequence of the acceleration of the different effects, according to the period of circulation in the state of fever, a greater life; and that a certain amount of disturb- amount of arterial blood, and, consequently ance, which produces disease in the adult of oxygen, is conveyed to the diseased part, state, may be without influence in childhood' as well as to all other parts; and if the acor in old age. A cause of disease may, tive force in the healthy parts continue unlwhen it is added to the cause of waste in, old form, the whole action of the excess of oxy~ age, produce death (annihilate all resistance gen must be exerted on the diseased part on the part of the vital force;) while in the alone. adult state it may produce only a dispropor- According as a single organ, or a system tion between supply and.waste; and in in- of organs, is affected, the-change of matter fancy, only an equilibrium between supply extends to one part alone, or to the whole and waste (the abstract state of health.) affected system. A cause of disease which strengthens the Should there be formed, in the diseased causes of' supply, either directly or indirectly parts, in consequence of the change of matby weakening.the action of the causes of ter, from the elements of the blood or of the waste, destroys, in the child and in the tissue, new products,' which the neighbouradult, the relative normal state of health; ing parts cannot employ for their own vital while in old age it merely brings the waste functions i-should the surrounding parts, and supply into equilibrium. moreover, be unable to convey these proA child, lightly clothed, can bear cooling ducts to other parts, where they may unby a low external temperature without in- dergo transformation, then these new projury to health; the force available for me- ducts will suffer, at the place where they chanical purposes and the temperature of have been formed, a process of decomposiits body increases with the change of matter tion analogous to fermentation or putrewhich follows the cooling; while a higher faction. temperature, which impedes the change of In certain cases, medicine removes these matter, is followed by disease. diseased conditions, by exciting in the viOn the other hand, we see, in hospitals cinity of the diseased part, or in any conand charitable institutions (in Brussels, for venient situation, an artificial diseased state example) in which old people spend the last (as by blisters, sinapisms, or setons); thus yearsof life, when the temperature of the dor- diminishing, by means of artificial disturmitory in winter sinks 2 or 3 degrees below bance, the resistance offered to the external the usual point, that by this slight degree of causes of change in these parts by the vital cooling the death of the oldest and weakest force. The physician succeeds in putting males -as well as females is brought about. an end to the original diseased condition, They are found lying tranquilly in bed, when the disturbance artificially excited (or without the slightest symptoms of disease, the diminution of resistance in another part) or of the uisual recognizable causes of death. exceeds in amount the diseased state to be A deficiency of resistance, in a living overcome. part, to the cause of waste is, obviously, a The accelerated change of matter and the deficiency of resistance to the action of the elevated'temperature in the diseased'part oxygen of the atmosphere. show, that the resistance offered by the vital'When, from any cause whatever, this re- force to the action of oxygen is feebler than sistance diminishes in a living part, the in the healthy state. But this resistance change of matter increases in an equal de- only ceases entirely when death takes place. gree. By the artificial diminution of resistance in Now, since the phenomena of motion in another part, the resistance in the diseased the animal body are dependent on the organ is not indeed directly strengthened; change of matter, the increase of the change but the chemical action (the cause of the of matter in any part is followed by an in- change of matter) is diminished in the crease of all motions. According to the con- diseased part, being directed to another part, ducting power of the nerves, the available where the physician has succeeded in proforce is carried away by the nerves of invo- ducing a still more feeble resistance to the luntary motion alone, or by all the nerves change of matter (to the action of oxygen). together. A complete cure of the original disease Consequently, if, in consequence of a dis- occurs, when external action and resistance, eased transformation of living tissues, a in the diseased part, are brought into equiligreater amount of force be generated than is brium. Health and the restoration of the required for the production of the normal diseased tissue to its original condition folmotions, it is seen in an acceleration of all or low, when we are able so far to weaken the some of the involuntary motions, as well as disturbing action of oxygen, by any means, in a higher temperature of the diseased part. that it becomes inferior to the resistance ofThis condition is called fever. fered by the vital, force, which, although When a great excess of force is roduced enfeebled, has never ceased to act; for this by change of matter, the force, since it can proportion between these causes of change only be consumed by motion, extends itself is the uniform and necessary condition of to the apparatus of voluntary mction. increase of mass in the living organis!i. 76' ANIMAL CHEMISTRY. In cases of a different kind, where artifi-'are, according to the preceding exposition, cial external disturbance produces no effect, not the producers, but only the conductors the physician adopts other indirect methods of the vital force; they propagate motion, to exalt the resistance offered by the vital and behave towards other causes of motion, force. These methods, the result of ages which in their manifestations are analogous of experience, are such, that the most per- to the vital force, towards a current of elecfect theory could hardly have pointed them tricity, for example, in a precisely analoout more acutely or more justly than has gous manner. They permit the current to been done by the observation of sagacious traverse them, and present, as conductors practitioners. He diminishes, by blood-' of electricity, all the phenomena which they letting, the number- of the carriers of oxy- -exhibit as conductors of the vital force. In gen, (the globules,) and by this means the the present state of our knowledge, no one, conditions of change of matter; he excludes probably, will imagine that electricity is to from the food all such matters as are capa- be considered as the cause of the phenomena ble of conversion into blood; he gives of motion in the body; but still, the medichiefly or entirely non-azotized food, which cinal action of electricity, as well as that of supports the respiratory process, as well a magnet, which, when placed in contact as fruit and vegetables, which contain the with the body, produces a current of elecalkalies necessary for the secretions. tricity, cannot be denied. For to the exIf lie succeed, by these means, in dimi- isting force of motion or of disturbance there nishing the action of the oxygen in the blood is added, in the electrical current, a new on the diseased part, so far that the vital cause of motion and of change in form and force of' the latter, its resistance, in the structure, which cannot be considered as alsmallest degree overcomes the chemical ac- together inefficient. tion; and if' he accomplish this, without ar- Practical medicine, in many diseases, resting the functions of the other organs, makes use of cold in a highly rational manthen restoration to health is certain. ner, as a means of exalting and accelerating, To the method of cure adopted in such in an unwonted degree, the change of matter. cases, if employed with sagacity and acute This occurs especially in certain morbid conobservation, there is added, as we may call ditions in the substance of the centre of the it, an ally- on the side of the diseased organ, apparatus of motion;, when a glowing heat and this is the vital force of the healthy and a rapid current of blood towards the parts. For, when blood is abstracted, the head point out an abnormal metamorphosis, external causes of change are diminished of the brain. When this condition continues also in them, and their vital force, formerly beyond a certain time, experience teaches neutralized by these causes, now obtains the that all motions in the body cease. If the preponderance. The change of matter, in- change of matter be chiefly confined to the deed, is diminished throughout tile body, brain, then the change of matter, the geneand with it the phenomena of motion: but ration of force, diminishes in all other parts. the sum of all resisting powers, taken to- By surrounding the head with ice, the temgether, increases in proportion as the perature is lowered, but the cause 6f the amount of the oxygen acting on them in the liberation of heat continues; the metamorblood is diminished. In the sensation of phosis, which decides the issue of the dishunger, this resistance, in a certain sense, ease, is limited to a short period. We must makes itself known; and the preponderating not forget, that the ice melts and absorbs vital force exhibits itself, in many patients, heat from the diseased part; that if the ice when hunger is felt, in the form of an ab- be removed before the completion of the normal growth, or* in abnormal metamor- metamorphosis, the temperature again rises; phosis of certain parts of organs. Synpa- that far more heat is removed by means of thy is the transference of diminished resist- ice than if we were to surround the head ance from one part, not exactly to the next, with a bad conductor of heat. There has but to more distant organs, when the func-: obviously been liberated in an equal time a tions of both mutually influence each other. far larger amount of heat than in the state When the action of the diseased organ is of health; and this is only rendered possible connected with that of another-when, for by an increased supply of oxygen, which example, the one no longer produces the must have determined a more rapid change matters necessary to the performance of the of matter. functions of the other —then the diseased The self-regulating steam engines, in condition is transferred, but only apparently, which, to produce a uniform motion, the to the latter. human intellect has shown the most adIn regard to the nature and essence of the mirable acuteness and sagacity, furnish no vital force, we can hardly deceive ourselves, unapt image of what occurs in the animal when we reflect, that it behaves, in all its bodvy. manifestations, exactly like other natural Every one knows, that in the tube which forces; that it is devoid of consciousness or conveys the steam to the cylinder where the of volition, and is subject to the action of a piston-rod is to be raised, a stop-cock of blister. peculiar construction is placed, through The nerves, which, accomplish the volun- which all the steam must pass. By an ar-, tary and involuntary motions in the body, rangement connected with the regulating THEORY OF RESPIRATION. 77 -wheel, this stop-cock opens when the wheel It is only by a just application of it, prinmoves slower, and closes more or less corn- ciples that any theory can produce really pletely when the wheel moves faster than is beneficial results. The very same method required for a uniform motion. When it of cure may restore health in one individual, opens, more steam is admitted, (more force,) which, if applied to another, may prove fatal and the motion of the machine is accel.e- in its effects. Thus in certain inflammatory rated. When it shuts, the steam is more or diseases, and in highly muscular subjects, less cut off, the force acting on the piston- the antiphlogistic treatment has a very high rod diminishes, the tension of the steam in- value; while -in other cases blood-letting creases, and this tension is accumulated for produces unfavourable results. The vivifysubsequent use. The tension of the vapour, ing agency of the blood must ever continue or the force, so to speak, is produced by to be the most important condition in the change of matter, by the combustion of restoration of a disturbed equilibrium, which coals in the fire-place. The force increases result is always dependent on the saving of (the amount of steam generated and its ten- time; and the blood must, therefore, be consion increase) with the temperature in the sidered and constantly kept inview, as the fire-place, which depends on the supply of ultimate and most powerful cause of a lastcoals and of air. There are in these engines ing vital resistance, as well in the diseased other arrangements, all intended for reoula- as in the unaffected parts of the body. tion. When the tension of steam in the It is obvious, moreover, that in all disboiler rises beyond a certain point, the pas- eases where the formation of contagious sages for admission of air close themselves; matter and of exanthemata is accompanied the combustion is retarded, the supply of by fever, two diseased conditions simultaforce (of steam) is diminished. When the neously exist, and two processes are simulengine goes slower, more steam is admitted taneously completed; and that the blood, as to the cylinder, its tension diminishes, the it were by re-action (i. e. fever) becomes a air passages are opened, and the cause of means of' cure, as being the carrier of that disengagement of heat (or production of substance (oxygen) without the aid of which force) increases. Another arrangement sup- the diseased products cannot be rendered plies the fire-place incessantly with coals in harmless, destroyed, or expelled from the proportion as they are wanted. body; a means of cure by which, in short, If we now lower the temperature at any neutralization or equilibrium is effected. part'of the boiler, the tension within is di- IV. THEORY OF RESPIRATION.-During minished; this is immediately seen in the the passage of the venous blood through regulators of force, which act precisely as the lungs, the globules change their colour; if we had removed -from the boiler a certain and with this change of colour, oxygen is quantity of steam (force.) The regulator absorbed from the atmosphere. Further, and the air-passages open, and the machine for every volume of oxygen absorbed, an supplies itself with more coals. equal volume of carbonic acid is, in most The bodvy, in regard to the production of cases, given out. heat and of force, acts just like one of these The red globules contain a compound of machines. With the lowering of the ex- iron; and no other constituent of the body ternal temperature,'the respirations become contains iron. deeper and more frequent; oxygen is sup- Whatever change the other constituents plied in greater quantity and of greater den- of the blood undergo in the lungs, thus sity; the change of matter is increased, and much is certain, that the globules of venous more food must be supplied, if the tempera- blood experience a change of colour, and ture of the body is to remain unchanged. that this change depends on the action of It is hardly necessary to mention, that in oxygen. the body the tension of vapour cannot, any Now we observe that the globules of artemore than an electrical current, be consi- rial blood retain their colour in the larger dered the cause of the production of force. vessels, and lose it only during their pasFrom the theory of disease developed in sage through the capillaries. All those conthe preceding pages, it follows obviously, stituents of venous blood, which are capable that a deceased condition once established, of combining with oxygen, take up a corin' any part of the body, cannot be made to responding quantity of it in the lungs. Exdisappear by the chemial action of a re- periments made with arterial serum have medy. A limit may be put by a remedy shown, that when in contact with oxygen to an abnormal process of transformation; it does not diminish the volume of that gas. that process may be accelerated or retarded; Venous blood, in contact with oxygen, is but;hiis alone does not restore the normal reddened, while oxygen is absorbed; and a (healthy) condition. corresponding quantity of carbonic acid is The art of the physician consists in the formed. knowledge of the means which enable him It is evident that the chance of colour in to exercise an influence on the deuration of the venous globules depends on the combithe disease; and in the removal of all disturb- nation of some one of their elements with ing causes, the action of which strengthens oxygen; and that this absorption of oxygen or increases that of the actual cause of is attended with the separation,of a certain disease. quantity of carbonic acid gas. rat 78 ANIMAL CHEMISTRY. This carbonic acid is not separated from The compounds of protoxide of iron posthe serum; for the serum does not possess sess the property of depriving other oxidized the property, when in contact with oxygen, compounds of oxygen; while the compounds of giving off carbonic acid. On the con- of peroxide of iron, under other circumtrary, when separated from the globules, it stances, give up oxygen with the utmost absorbs from half its volume to an equal facility. volume of carbonic acid, and, at ordinary Hydrated peroxide of iron, in contact temperatures, is not saturated with that gas. with organic matters destitute of sulphur, (See the article "Blut," in the " Handwor- is converted into carbonate of the protoxide. terbuch der Chemie, von Poggendorff, Woh- Carbonate of protoxide of iron, in conler, und Liebig, p. 877.) tact with water and oxygen, is decomposed; Arterial blood, when drawn from the all the carbonic acid is given off, and, by body, is soon altered; its florid colour be- absorption of oxygen, it passes into the comes dark red. The florid blood, which hydrated peroxide, which may again be conowes its colour to the globules, becomes verted into a compound of the protoxide. dark by the action of carbonic acid, and this Not only the oxides of iron, but also the change of colour affects the globules, for cyanides of that metal, exhibit similar proflorid blood absorbs a number of gases which perties. Prussian blue contains iron in do not dissolve in the fluid part of the blood combination with all the organic elements when separated from the globules. It is of the body; hydrogen and oxygen (water) evident, therefore, that the globules have the carbon and nitrogen (cyanogen.) power of combining with gases. When it is exposed to light, cyanogen is The globules of the blood change their given off, and it becomes white; in the dark colour in different gases; and this change it extracts oxygen, and recovers its blue may be owing either to a combination or to colour. a decomposition. All these observations, taken together, Sulphuretted hydrogen turns them black- lead to the opinion that the globules of arteish green and finally black; and the original rial blood contain a compound of iron satured colour cannot, in this case, be restored rated with oxygen, which, in the living by contact with oxygen. Here a decompo- blood, loses its oxygen during its passage sition' has obviously taken place. through the capillaries. The same thing The globules darkened by carbonic acid occurs when it is separated from the body, become again florid in oxygen, with disen- and begins to undergo decomposition (to pugagement of carbonic acid.' The same thing trefy.) The compound, rich in oxygen, takes place in nitrous oxide. It is clear that passes, therefore, by the loss of oxygen (rethey have here undergone no decomposition, duction) into one far less charged with that and, consequently, they possess the power element. One of the products of oxidation of combining with gases, while the compound fbrmed in this process is carbonic acid. The they form with carbonic acid is destroyed by compound of iron in the venous blood posoxygen. When left to themselves, out of sesses the property of combining with carthe body. the compound formed with oxy- bonic acid; and it is obvious, that the glogen again becomes dark, but does not bules of the arterial blood, after losing a part recover its florid colour a second time by of their oxygen, will, if they meet with carthe action of oxygen. bonic acid, combine with that substance. The globules of the blood contain a com- When they reach the lungs, they wil' pound of iron. From the never-failing again take up the oxygen they have lost; presence of iron in red blood, we must con- for every volume of oxygen absorbed, a corelude, -that it is unquestionably necessary responding volume of carbonic acid will be to animal life; and, since physiology has separated; they will return to their former proved, that the globules take no share in state; that is, they will again acquire the the process of nutrition, it cannot be doubted power of giving off oxygen. that they play a part in the process of re- For every volume of oxygen which the spiration. globules can give off, there will be formed The compound of iron in the globules (as carbonic acid contains its own volume has the characters of an oxidized com- of oxygen, without condensation) neither pound; for it is decomposed by sulphuretted more nor less than an equal volume of carhydrogen, exactly in the same way as the bonic acid. For every volume of oxygen oxides or other analogous compounds of which the globules are capable of absorbing, iron. By means of diluted mineral acids, no more carbonic acid can possibly be sepaperoxide Isesquioxide) of iron may be ex- rated than the volume of oxygen can protracted, at the ordinary temperature, from duce. the fresh or dried red colouring matter of When carbonate of protoxide of iron, by the blood. the absorption of oxygen, passes into the The characters of the compounds of iron hydrated peroxide, there are given off, for may, perhaps,assist us to explain the share every volume of oxygen necessary to the which that metal takes in the respiratory change from protoxide to peroxide, four voprocess. No other metal can be compared lumes of carbonic acid gas. with iron, for the remarkable properties of But from one volume of oxygen only one its compounds. volume of cabronic acid can be produced; THEORY OF RESPIRATION. 79 and the absorption of one volume of oxygen tion which takes place there, the constan can only cause, directly, the separation of temperature of the lungs -is kept up; while an equal body of carbonic acid. Conse- the heat of the rest of the body is supplied quently, the substance or compound which by the latter. has lost its oxygen, duringthe passage of A man, who expires daily 13'9 oz. of cararterial into venous blood, must have been bon, in the form of carbonic acid, consumes, capable of absorbing or combining with car- in 24 hours, 37 oz. of oxygen, which occupy bonic acid; and we find, in point of fact, a space equal to 807 litresh5l,648 cuoie that the living blood is never, in any state, inches (Hessian.) saturated with carbonic acid; that it is capa- If we reckon 18 respirations to a minute, ble of taking up an additional quantity,' we have, in 24 hours, 25,920 respirations; without any apparent disturbance of the and, consequently, in each respiration, there function of the globules. Thus, for exam- are taken into the blood 5164=- -1-99 cubic ple, after drinking effervescing wines, beer, inch of oxygen. or mineral waters, more carbonic acid In one minute; therefore, there are added must necessarily be expired than at other to the constituents of the blood 18 X 1-99= times. In all cases, where the oxygen of 35'8 cubic inches of oxygen, which, at the the arterial globules has been partly ex- ordinary temperature, weigh rather less than pended, otherwise' than in the formation of 12 grains. carbonic acid, the amount of this latter gas If we now assume, that in one minute 10 expired will correspond exactly with that lbs. of blood pass through the lungs, (Miller, which has been formed; less, however, will Physiologie, vol. i. p. 345,) and that this be given out after the use of fat and of still quantity of blood measures 320 cubic inches, wines, than after champagne. then 1 cubic inch of oxygen unites with 9 According to the views now developed, cubic inches of blood, very nearly. the globules of arterial blood, in their pas- According to the researches of D6nis, sage through the capillaries, yield oxygen Richardson, and Nasse (Handwhrterbuch to certain constituents of the body. A small der Physiologie, vol. i. p. 138,) 10,000 parts portion of this oxygen serves to produce'the of blood contain 8 parts of peroxide of iron. change of matter, and determines the sepa- Consequently, 76,800 grains (10 lbs. Hesration of living parts and their conversion sian) of blood contain 61`54 grains of perinto lifeless compounds, as well as the form- oxide of iron in arterial blood, = 55'14 of ation of the secretions and excretions. The protoxide in venous blood. greater part, however, of the oxygen is em- Let us now assume that the iron of the ployed in converting into oxidized cornm- globules of venous blood is in the state of pounds the newly formed substances, which protoxide. It follows, that 55-14 grains of no longer form part of the living tissues. protoxide of iron, in passing through the In their return towards the heart, the lungs, take up, in one minute, 6-40 grains globules which have lost their oxygen com- of oxygen (the quantity necessary to conbine with carbonic acid, producing venous vert it into peroxide.) But since, in the blood; and, when they reach the lungs, an same time, the 10 lbs. of blood have taken exchange takes place between this carbonic up 12 grains of oxygen, there remain 5'60 acid and the oxygen of the atmosphere. grains of oxygen, which combine with the The organic compound of iron, which other constituents of the blood. exists in venous blood, recovers in the lungs Now, 55,14 grains of protoxide of iron the oxygen it has lost, and, in consequence combine with 34-8 grains of carbonic acid, of this absorption of oxygen, the carbonic which occupy the volume of73 cubic inches. acid in combination with it is separated. It is obvious, therefore, that the amount of All the compounds present in venous iron present in the blood, if in the state of blood, which have any attraction for oxygen, protoxide, is sufficient to furnish the means are converted, in the lungs, like the glo- of carrying or transporting twice as much bules, into more highly oxidized com- carbonic acid as can possibly be formed by pounds; a certain amount of carbonic acid the oxygen absorbed in the lungs. is formed, of which a part always remains The hypothesis just developed rests on dissolved in the serum of the blood. well-known observations, and, indeed, exThe quantity of carbonic acid dissolved, plains completely the process of respiration, or, of that combined with soda, must be as far as it depends on the globules of the equal in venous and arterial blood, since blood. It does not exclude the opinion that both have the same temperature; but arterial carbonic acid may reach the lungs in other blood, when drawn, must, after a short time, ways; that certain other constituents of the contain a larger quantity of carbonic acid blood may give rise to the formation of carthan venous blood, because the oxygen of bonic acid in the lungs. But all this has no the globules is expended in producing that connexion with that vital process by which compound. the heat necessary-for the support of life is Hence, in the animal organism, two pro- generated in every part of the body. Now cesses of oxidation are going on; one in it is this alone which, for the present, can the lungs, the other in the capillaries. By be considered as the object truly worthy of means of the former, in spite of the degree investigation. It is not, indeed, uninterest of cooling, and of the increased evapora- ing to inquire, why dark blood becomes 80 ANIMAL CHEMISTRY. florid by the action of nitre, common salt,, no lifeless compounds are separated, neither &c.; but this question has no relation to bile nor urine can be formed; and the temrnthe natural respiratory process. perature of the body must sink. The frightful effects of sulphuretted hy- This state of matters soon puts a stop to drogen, and of prussic acid, which, when the process of nutrition, and sooner or later inspired, put a stop to all the phenomena death must follow, but unaccompanied by of motion in a few seconds, are explained febrile symptoms, which in this case is a in a natural manner by the well-known very important fact. action of these compounds on those of iron, This example has been selected in order when alkalies are present; and free alkali to show the importance and probable advanis never absent in the blood. tage of an examination of the blood in analoLet us suppose that the globules lose their gous diseased conditions. It cannot be, in property of absorbing oxygen, and of after- the slightest degree, doubtful that the funcwards giving up this oxygen and carrying tion ascribed to the blood globules may be off the resulting carbonic acid; such a hy- considered as fully explained and cleared pothetical state of disease must instantly up, if, in such morbid conditions, we shall become perceptible in the temperature and discover a change in their form, structure, other vital phenomena of the body. The or chemical characters, a change which change of matter will be arrested, while must be recognizable by the use of approyet the vital motions will not be instantly priate re-agents. stopped. If we consider the force which determines The conductors of force, the nerves, will the vital phenomena as a property of cer-. convey, as before, to the heart and intestines tain substances, this view leads of itself tc the power necessary for their functions. a new and more rigorous consideration of This power they will receive from the mus- certain singular phenomena, which these cular system, while, as no change of matter very substances exhibit, in circumstances in takes place in the latter, the supply must which they no longer make a part of living soon fail. As no change of matter occurs, organisms. APPENDIX: CONTAINING THE ANALYTICAL EVIDENCE- REFERRED TO IN THE SECTIONS IN VWHICH ARE DESCRIBED THE CHEMICAL PROCESSES OF RE. SPIRATION, OF NUTRITION, AND OF THE METAMORPHOSIS OF TISSUES. *** The Notes correspond with the numbers in parenthesesin the text. All the Analyses quoted, which have the mark * attached, have been made in the chemical laboratory of the University of Giessen. INTRODUCTION TO THE ANALYSES. THE method formerly employed to exhibit the differences in composition of different substances, that, namely, of giving the proportions of the various elements in 100 parts, has been long abandoned by chemists; because it affords no insight into the relations which exist between two or more compounds. In order to give some proofs of this statement, we shall here state, in that form, the composition of aldehyde and acetic acid, of oil of bitter almonds and benzoic acid. Acetic acid. Aldehyde. Benzoic acid. Oil of bitter almonds. Carbon 40'00 55'024 69'25 79-56 Hydrogen 6'67 8-983 4-86 5-56 Oxygen 53-33 35-993 25.89 14-88 Now aldehyde is converted into acetic acid, and oil of bitter almonds into benzoic acid, simply by the addition of oxygen, without any change in regard to the other elements. This important relation cannot be traced in the mere numerical results of analysis as above given; but if the composition of the related compounds be expressed in formulae, according to equivalents, the connexion in each case becomes obvious, even to him who knows no more of chemistry than that, C represents an equivalent or combining portion of carbon, H an equivalent of hydrogen, and O an equivalent of oxygen. Formula- Formula of acetic acid. of aldehyde. of benzoic acid. of oil of bitter almonds C4H404. C4H402. C'4H604. C14H602. APPEN.DIX.-ANALYTICAL EVIDENCE. e: These formaule are exact expressions of the results of analysis, which, in each of the two cases quoted, refer to a fixed quantity of carbon;,in one to 4 equivalents, in the other to 14. They show, that acetic acid differs from aldehyde, and benzoic acid from oil of bitter almonds, only in the proportion of oxygen. Nor is it more difficult to understand the signification of the following formula. Cyamelide. 1 eq. cyanuric acid. 3 eq. hydrated cyanic acid. C6N3 3306_Cy3(= C6 3)03+3HO=3(CvO-HO)=_-CN3II3O6 -C6CN3H306. (In these formulae, N represents an equivalent of nitrogen, and Cy an equivalent of cyanogen. This latter substance being composed of 2 equivalents of carbon and I eq. of nitrogen, Cy -- C2N.) The first formula (that of Cyamelide) is what is called an empirical formula, in which the relative proportions of the elements are, indeed, exactly known, but where we have not even a theory, far less any actual knowledge, of the order in which they are arranged. The second formula is intended to express the opinion that 3 eq. of cyanogen ( — 6 eq. of carbon + 3 eq. of nitrogen) having united to form a compound atom or molecule, have combined with 3 eq. of oxygen and 3-eq. of water, to form 1 eq. of hydrated cyanuric acid. The third expresses the order in which the elements are supposed to be arranged in hydrated cyanic acid, the whole multiplied by 3. Each equivalent of cyanic acid is formed of 1 eq. of cyanogen, 1 eq. of oxygen, and 1 eq. of water; and hence the same number of atoms of each element, which together formed 1 eq. of cyanuric acid, is here so divided as. to yield 3 eq. of cyanic acid. We have here, therefore, the same absolute and relative amount of atoms of each element, arranged in three different ways; yet in each of these the proportions of the elements, calculated for 100 parts, must of course -be the same. It is easy, therefore, to see the advantage we possess by the use of formulin; that, namely, of exhibiting the relations existing between compounds of different composition; and that also of expressing the actual, probable, or possible differences between substances whose composition, -in 100 parts, is the same, while their properties, as in the case above quoted, are perfectly distn ct. It does not come within our province here to explain the method or rule by which the composition of a substance, in 100 parts, (as it is always obtained in analysis,) is expressed in a formula; we shall only describe the rule for calculating, from a given formula, the composition in 100 parts. For this purpose it must be noted that C, in a chemical formula, signifies a weight of carbon expressed by the number 76-437 (according to the most recent determinations 75'8 or 75'0, a variation which has no effect whatever on the formulae here adduced, all of which are calculated on the number 76'437), that H signifies a weight of hydrogen - 12-478; N a weight of nitrogen =177'04; and lastly, 0 a weight of oxygen - 100. The formula of proteine,, C48N6H0O14, expresses, therefore,48 times 76-437 3668'88 carbon, 6 times 177-040 _ 1062'24 nitrogen, 36times 12478- 449'26 hydrogen, 14 times 100'000 - 1400'00 oxygen. The sum gives a weight of 6580'38 proteine. ThereforeIn 100 parts. In 6580-38 parts of proteine are contained 3668-88 carbon 55'742 In 6580'38 ditto 1062'24 nitrogen 16'143 In 6580'38 ditto - 449-26 hydrogen 6'827 In 6580'38 ditto 1400'00 oxygen 21 288 100'000 The actual results of analysis, reduced to 100 parts, when compared wiih the above numbers, will show how far the assumed formula is corect; or, supposing the formula ascertained, they will show the degree of accuracy displayed by the experimenter. Thus the proportions in 100 parts, calculated from the formula, furnish an important check to the operator, and, conversely, the formula calculated from his results, when compared Kwith other known formulae, supplies a test of his accuracy, or of the purity of the substance analyzed. 11 82 ANIMAL CHEMISTRY. NOTE (1,) p. 14. CONSUMPTION OF OXYGEN BY AN ADULT. Iqn adult man. Carbon contained. consumes of oxygen produces of carbonic in the in 24 hours. acid in 24 hours. carbonic acid., According to, —---------- - cubic in. grains. cubic n. grain grains. Lavoisier and Seguin 46,037 15,661 14,930 8,584 2,820 French. Menzies... 51,480 17,625 English. Davy..... 45,504 15,751 31,680 17,811 4,853 do. Allen and Pepys.. 39,600 13,464 39,600 18,612 5,148 do. NOTE (2,) p. 14. COMPOSITION OF DRY BLOOD (see Note 28.) In 100 parts. In 4.8 lbs. Hessiaa = 36,864 grains. Carbon.. 5196... 19154-5 Hydrogen.. 725... 2672-7 Nitrogen.. 1507... 5555'4 Oxygen.. 2130... 7852-0 Ashes. 4-42.. 16294 100'00 36864'0 Grains. Grains. 19154-5 carbon form, with 50539'5 oxygen, carbonic acid. 2672'7 hydrogen do. 21415-8 do. water. Sum — 71955-3 do. Deduct oxygen present = 7852 in blood.7 5 Remain 64103'3 grains of oxygen, required for the complete combustion of 4-8 lbs. of dry blood. It is assumed in this calculation, that 24 lbs. of blood yield 4-8 lbs. (20 per cent.) of dry residue. The remainder, 80 per cent., is water. NOTE (3,) p. 14. DETERMINATION OF THE AMOUNT OF CARBON EXPIRED. 1. ANALYSIS OF Fceces. 2-356 dry faces left 0-320 ashes (13-58 per cent.) 0-352 dry foeces yielded 0-576 carbonic acid, and 0-218 water. Lentils. 0-566 lentils, dried at 212~, yielded 0-910 carbonic acid, and 0-366 water. Pease. 1'060 pease, dried at 2120, left 0'037 ashes. 0'41,6 do. do. yielded 0'642 carbonic acid, and 0'241 water. Potatoes. 0'443 dried potatoes yielded 0'704 carbonic acid, and 0-248 water. Black Bread (Schwarzbrod.) 0-302 dried black bread yielded 0'496 carbonic acid, and 0-175 water. 0-241 do. 0-393 do. 0'142 do. From the above, which are the direct results of experiment, the composition in 100 parts is calculated as in the following table. 2. COMPOSITION Of Feeces. Of Black Bread. Of Potatoes. Of Flesh. Playfair.* Bceckmann.* Boussingault. Bceckmann.* Carbon 45-24 45-09 45-41 44-1 43'944 (See note 28.) Hydrogen 6'88 6'54 6-45 5'8 6.222 Nitroxygen 34-73 45'12 44-89 45-1 44-919 Oxygen 3 Ashes 13-15 3'25 3-25 - 5'0 4-915 100-00 100'00 100.00 100'0 100'000 Water 300'00 400'00 APPENDIX.-ANALYTICAL EVIDE NCE. 83 Of Pease. Of Lentils. Of Beans. Playfair.* Playfair.* Plavyfair.* Carbon.... 35743 37'38 38-24 Hydrogen... 5401, 554 5-84 Nitrogen 39'366 37-98 38-10 Ashes... 3490 3'20 371i Water... 16000 15'90 14-11 100 000 100'00 100'00 Fresh Meat. Potatoes. Black Bread. Baeckmann.* Boussingault.* Bceckmann.* Water. 75 74'8 72'2 73'2 33 31'418 Dry Matter. 25 25-2 27'8 26'8 -67 68.592 100 100'0 100'0 100'0 100 100'000 3. CALCULATION, with the help of the preceding data, of the amount of carbon expired by an adult man. The following results are deduced from observations made (see table) on the average daily consumption of food, by from 27 to 30 soldiers in barracks for a month, or by 855' men for one day. The food, consisting of bread, potatoes, meat, lentils, pease, beans, &c., was weighed, with the utmost exactness, every day during a month (including even pepper, salt, and butter.;) and each article of food was separately subjected to ultimate analysis. The only exceptions, among the men, to the uniform allowance of food, were three soldiers of the guard, who, in addition to the daily allowance of 2 lbs. of bread, received, during each of the periods allotted for the pay of the troops, 2~ lbs. extrai and one drummer who, in the same period, left 24 lbs. unconsumed. According to an approximative report by the sergeant-major, each soldier consumes daily, on an average, out of barracks, 3 oz. of sausage, 3 oz. of butter, i pint of beer, and jad pint of brandy; the carbon of which articles amounts to more than double that of the fbaces and urine taken together. In the soldier, the faeces amount daily, on an average, to 54 oz.; they contain 75 per -cent. of water, and the dry residue contains>45-24 per cent. of carbon, and 13'15 per cen't. of ashes. 100 parts of fresh fieces consequently contain 11-31 per cent. of carbon, very nearly the same proportion as in fresh meat. In the calculation, the carbon of the feces and of the urine has been assumed as equal to that of green vegetables, and of the food (sausages, butter, beer, &c.) consumed in the alehouse. From the observations, as recorded in the table, the following conclusions are deduced. Flesh. —Meat devoid of fat, if reckoned at 74 per cent. water, and 26 per cent.' dry matter, contains in 100 parts very nearly 13-6 parts of carbon. Ordinary meat contains both fat and cellular tissue, which together amount to Ith of the weight of the meat as bought from the butcher. The number of ounces consumed (by 855 men) was 4,448, consisting, therefore, of' 3812-5 oz. of flesh, free from fat, containing of carbon 518-5 oz. 635-5 oz. of fat and cellular tissue, ditto 449-0 oz. 4448-0 oz. In all, carbon 967-5 oz. With the bones, the meat, as purchased, contains 29 per cent. of fixed matter, including bones; 4,448 oz. of flesh therefore contain 448 oz. of dry bones. These have not been included in the calculation, although, when boiled, they yield from 8'to 10 per cent. of gelatine, which is taken, as food in the soup. Fat.-The amount of fat consumed was 56 oz.; which, the carbon being calculated at 80 per cent., contain in all 44-8 oz. of carbon. Lentils, pease and beans. -There were consumed 53-5 oz. of lentils, 185 5 oz. of pease and 218 oz. of beans. Assuming the average'amount of carbon: in these vegetables to be 37 per cent., the total quantity of carbon consumed in this form was 169.1 oz. Potatoes.-100 parts of fresh potatoes contain 12'2 parts of carbon. In the 15'876 oz. of potatoes' consumed, therefore, the amount of carbon was 1936-85 oz. Bread.-855 men eat daily 855 times 32 oz., besides 36 lbs. of bread in the soup, which in' all amounts to 27,936 oz. 100 oz. of fresh bread contain, on an averag&, 30'15 oz. of carbon; consequently the carbon consumed in;he bread amounts to- 8771'5 oz. The total consumption,'therefore, was, In the meat..... 96750 oz. of carbon In the fat. 44'80 ditto In the lentils,'pease, and beans 169.10 ditto In the potatoes. 1936.85 ditto In the bread. 8771.50 ditto Consumed by 855 men.. 11889'75 ditto Consumed by I man e. *. 13'9 ditto TABLE I. (to Note 3.) Containing a Summary of the Victuals consumed during JVovember, 1840, by a Company of the Body Guard of the Grand Duke of Hesse Darmstadt. 184_. No. o f.cnb' ce a s Bean?epper. |Nr1840. ~No. of menBeefPork. Potaoes. Peas. BeansLenils Sour- Green Bred SaOnionLeeks, Pepper. 1840.r~lYtaoe.Pes.Ban, enil.krut tahSalt. eeks, Price in Fat or Vincar November in the supplied krout. in Soup. J reutzers. Lard. period from the with food. 3kr.l d. lbs. lbs. lbs. oz. lbs. oz. lbs. oz. lbs. oz. lbs. lbs. lbs. lbs. lbs. hr. oz. pints. st to 5th 139 36 9 147 0 4 151 3 7 -. 20 12 5 4- 4 21 13 6th to 10th 145 37 9 165 6 - 16 70 71 5 3~ 2 10 - lth to 15h 136 36 9 153 2 - 3 74- - 16 42 7 1 4 3 2 8 16th co 20th 136 37 9 17710 3 5 3 7- 16 12 6 4 ~ 4- 3. s Sausages. 21st to 25th 147 39 71 171 8 - 3 5 36 |7 5- 5 2 - 5 | 1 26th.to 30th 152 30 l9- 177 10 35 3 5 32 2 4 3 21 5 -.~~~~4 I. - |Total, 855 215 63 992 4 11 9 |13 14 3 5j 100 172 36 28 20 | 15 1 56 | | The average lbs. lbs. lbs. oz. oz. oz. Ioz. lbs. oz. lbs. lb. lb. oz kr. oz. pint. No. of men Monthly 731 212 34 13 6T-!L- 71-a-5 l 15- 3 lI91l 6171i l-6 11 j7 l3 3 daily fed is l_ OZ. I JL3 OZ. OZ.2 OZ N. B.-As all the weights mentioned in the text of this work are Hessian pounds and ounces, the different articles in this table have been reduced to the same weights, excepting the Pepper and Vinegar, the amount of both of which is so small that they may be omitted, without affecting the general result. For the benefit of those who may wish to reduce these weights to avoirdupois weight, it may here be mentioned, that 1 lb. Hessian=16 oz. Hessian==7680 grains Hessian,7712 grains avoirdupois. Consequently, since the 1 lb. avoirdupois is=7000 grains Troy, 1 lb. avoirdupois: lb. Hessian:: 7000: 7712, or as 1: 11017; and 1 oz. Hessian= —482 grains Troy (1 o. Troy is=480 grains,) while oz. avoirdupois is=4375 grains Troy. lb. oz.] oz. / oz. I oz. / oz. ~-t~Y APPENDIX.-ANALYTICAL EVIDENCE. 85 The faces of a soldier weigh 5'5 oz., and contain, in the fresh state, 11 per cent. of carbon. For 86 kreutzer (about 2s. 5d. sterling,) there may be bought, on an average, 172 lbs. of vegetables, such as cabbages, greens, turnips, &c.; 25 maas of sour krout weigh 100 lbs.; and. for 482 kreutzer (Is. 5d. sterling,) there are brought, on an average, 244 lbs. of onions, leeks, celery, &c.* 855 men consunmed Of green vegetables.2,802 oz. Of sour krout.1,600 Of onions, &c. 388.,n all 4,790 And one man....... 5'6 oz. For this reason, the carbon of the last mentioned articles of food has been assumed as equal to that of the fecees and urine. Sausages, brandy, beer, in short, the small quantity of food taken irregularly in the alehouse, has not been included in the calculation. The daily allowance of bread, being uniformly 2 lbs. per man, with the exceptions formerly mentioned, has not been inserted in the table, which includes only those matters of which, from the daily allowance being variable, an average was required. The small quantity of bread in the table is that given in the soup, which Is over and above the daily supply. NOTE (4.) See next page. NOTE (5,) p. 15. TEMPERATURE OF THE BLOOD AND FREQUENCY OF THE PULSE. According to Prevost and Dumas. The frequency The mean temperature is of the pulse of the respiration F. in the minute. in the minute. In the Pigeon. 107-6~.. 136. 34 Common Fowl 106'7 140 30 Duck... 1085. 170. 21 kRaven.. 108-5. 110. 21 Lark. 1172. 200. 22 Simia Callitriche - 95'9. 90.. 30 Guinea Pig 100'4. 140.. 36 Dog. 99'3 90 28 Cat. 101-3. 100 24 Goat... 025 84. 24 Hare. 1004 120 36 Horse... 982. 56.. 16 Man... 986.. 72..18 Man (Liebig).. 977~.. 65. 17 Woman (Liebig). 98-2.. 60.. 15 The temperature of a child is 102'2~. The temperature of the human body, in the mouth or in the rectum, for example, is from 97'70 to 98'6~. That of the blood (Majendie) is from 100'6~ to 101-60. As a mean temperature, 99'50 has been adopted in this'worlk, page 15. NOTE (6,) p. 20. The prisoners in the house of arrest of Giessen receive daily 14 lb. of bread (24 oz.,) which contain 74 oz. of carbon. They receive, besides, 1 lb. of soup daily, and on each alternate day, 1 lb. of potatoes. 14 lb. of bread contains.... 725 oz. of carbon. 1 lb. of soup contains..... 075 ditto. i lb. of potatoes contains.... 100 ditto. Total..... 900 dittoJt * In the original table, the quantities of these vegetables are entered according to their value in Kreutzers, but they are here calculated by weight from tile above data, as this appeared better adapted for comparison in this country than the prices would have been.-ED. t At page 36 the carbon contained in the daily food of these prisoners is calculated at 84 oz., and HI TABLE 11.-Note (4,) p. 14. a FOOD CONSUMED BY A HORSE IN TWENTY-FOUR HOURS. FOOD CONSUMED BY A COW IN TWENTY-FOUR' HOURS. Weight Weight Salts Weight Weight Salts Articles of in the in the Carbon IHydro- Oxy- Nitro- and Articles of in the in the Hydro- Oxy- NItr - and food. fresh dry gen. Igen. gen. earthy andon food. fresh dryIgen. gen. gen. earthy-food. - fresh dry o gen. gen. gen. earthy state. staie. ( I i ~ I~matters.l I I state. state. matters. Hay 7500'6465 2961-0 323-2 -2502-0- 97-0 581-8'Potatoes 15000! 4170 1839-0 241-9 1830-6 50-0 208-5 Oats.2270 1927 977-0 123-3 707-2 42-4 77-1 After.Grass 7500 6315 2974-4 353-6 2204-0 151P5 631P5 Water- 16000 - - - 13.3 Water 60000 - - -- - - 50-0 Total 25770 8392-1 3938-0 446-5 3209-2 139-4 672-2 1Total 82500 10485 148134 5955 40346 201'5 8890 EXCRETIONS OF A HORSE IN TWENTY-FOUR HOURS. EXCRETIONS OF A' COW IN TWENTY-FOUR HOURS, Weight Weight Salts Weight Weight Salts C) in the in the Hydro- Oxy- Nitro- and in the in the Hydro- Oxy Nitro- and fscretions. Canbong Excretions. Carbon. fresh dry gen. gen. gen. earthy fiesh dry E~en. geng gen. I earthy. tg g state. state. matters, state. state. matters 5 UTrine 1330 302 108-7 l' 34'l84 37.8 109-9 Excrements. 28413 4000'0 1712-0 208-0 1508'0 92-0 480-0 c3 Excrements 14250 3525 1364'4 179-8 1328.9 -77-6 574-6 Urine 8200 960-8 261-4 25-0 253-7 36-5 384-2 -__ Milk 8539 1150-6 628'2 99-0 321'0`46-0 56-4 Total 15580 3827 1472-9 191'3 1363-0 115-4 684'5 T otal 45152 6111'4 2601-6. 332-0 2082'7 174-5 920-6 Total from the previous 25770 8392 3938'0 446'S 3209'2 139'4 672'2 Total of part of this 2 first part of 82500 10485'0 4813'4 595-5 4034'6 201' 889-0 Table. -this Table. Difference 10-190 4565 2465'1 255'2 1846-2 24-0 12-3 Difference 37348 4374'6 2211-8 263-5 1951-9 27-0 31-6 0or- j V - - - - - ~ + 01- or _ _ _ _ _ _ _ _ _ a Boussingault, Ann. de Ch. et de Phys., LXX., 136. The weights in this table are given in gramnmes. 1 gramme=15'44 grains Troy, very nearly. APPENDIX.-ANALYTICAL EVIDENCE. 87. NOTE (7,) p. 21. COMPOSITION OF THE FIBRINE AND ALBUMEN OF BLOOD. a. Albumen from Serum of Blood. Fibrine. Scherer.* Scherer. Mulder. -I. II, III, I. II. III. Carbon. 53'850 55'461 56'097 53'671' 54'454 54 56 Hydrogen. 6'983 7'201 6-880 6-878 7-069 6'90 Nitrogen. 15'673 15'673 15-681 15-763 15-762 15'72 Oxygen ) Sulphur. 23-494 21-655 22-342 23'688 22'715 22'82 Phosphorus. a Annalen der Chem. und Pharm., XXVIII., 74, and XL., 33, 36. For additional analyses of animal fibrine and albumen, see Note (27,) whica also contains analyses of the various animal tissues. NOTE (8,) p. 22. COMPOSITION OF VEGETABLE FIBRINE, VEGETABLE ALBUMEN, VEGETABLE CASEINE, AND VEGETABLE GLUTEN. VEGETABLE' FIBRINE. GLUTEN, As obtained from wheat flour. Sherer*a. Jones.*b Marcet.c Boussingault. I. II. III. IV. I. IT. Carbon. 53'064 54-603 54'617 53-83 55.7 53'5 Hydrogen. 7'132 7-302 7'491 7.02 14.5 15'0 Nitrogen 15'359 15-809 15'809 15-58 7-8 7'0 Oxygen ) Sulphur. 24-445 22-285 22-083 23-56 22-0 24-5 Phosphorus 3 I Ann. der Chem. und Pharm., XL., 7. b Ibid., XL., 65. c L. Gmelin's Theor. Chemie, II., 1092. VEGETABLE ALBUMEN, a. From Rye. Wheat. Gluten. Almonds. Jones.* Jfnes.* Varrentrapp & Will.* Jones.* Carbon. 54'74 55-01 54'85 57'03 Hydrogen.. 7'77 7'23 6-98 7'53 Nitrogen 15'85 159',. 15-88 13'48 Oxygen ) Sulphur >. 21,64 21'84 22'39 21'96 Phosphorus Boussingault. Varrentrapp and Will:* Carbon.. 52,7 Hydrogen. 6'9 Nitrogen.: 184 1570 Oxygen, &c.. 22'0 a Ann. der Chem. und Pharm., XI., 66, and XXXIX., 291. VEGETABLE CASEINE.a Sulphate of Caseine and Potash. Scherer.* Jones.* Varrentrapp and Will. Carbon... 54-13 55-05 51-41 51-24 Hydrogen... 7'156 7'59 7'83 6'77 Nitrogen.. 15'672 15-89 14'48 13'23 Oxygen, &c.. 23-034 21-47 - - a Ann. der Chem. und Pharm., XXXIX., 291, and XL., 8 and 67. VEGETABLE GLUTEN. Jones.*a Boussingault. Carbon... 5522 54'2 52'3 Hydrogen... 7'42 7-5 6'5 Nitrogen.. 15'98 13'9 18'9 Oxygen, &c... 21'38 24'4 22'3 a Ann. der Chem. und Pharm., XL., 66. The pure gluten, analyzed by Jones, was that portion of the raw gluten from wheat flour which is soluble in hot alcohol. The insoluble portion is vegetable fibrine, the analysis of which has been already given. Ile appendix in the original makes the number also 8'5, apparently by an error in adding up the above numbers, which yield the sum of 9 o&. Possibly there may be an error in excess in the proportion of carbon calculated for the soup, which, in that case, ought to te 0-25 oz.-EDITCR. 88..ANIMAL CHEMISTRY. NOTE (9,) p. 24. COMPOSITION OF ANIMAL CASEINE.a Scherer. From fresh From sour From milk by Albuminous submilk. milk. acetic acid. stance in milk.b I. I. II. IV. V. Carbon. 54-825 54-721 54-665 54-580 54'507 Hydrogen. 7-153 7-239 7'465 7-352 6'913 Nitrogen. 15-628 15-724 15-724 15-696 15'670 Sulyhun } 22-394 22-316 22-146 22'372 22'910 a Ann. der Chem. und Pharm., XL., 40 et seq. b This substance, called, in German, zieger, is contained in the whey of milk after coagulation by an acid. It is coagulated by heat, and very much resembles albumen. Mulder.a Carbon. 54'96 Hydrogen.... 715 Nitrogen...... 1589 Oxygen......2173 Sulphur...... 036 a For the analysis of vegetable caseine, see the preceding note. NOTE (10,) p. 27. AMOUNT OF MATTER SOLUBLE IN ALCOHOL IN THE SOLID EXCREMENTS OF THE HORSE AND COW. (WILL..) 18-3 grammes of dried horse-dung lost, by the action of alcohol, 0'995 gramme. The residue, wnen dry, had' the appearance of saw-dust, after it had been deprived, by boiling, of all soluble matter. 14'98 grammes of dry cow-dung lost, by the same treatment, 0'625 gramme. NOTE (11,) p. 28. COMPOSITION OF STARCH. C6 Strecker.* Calculated From From From From 19CH10010. Peas. Lentils. Beans. Buckwheat. Carbon. 44.91 44.33 44-46 44-I6 44'23 Hydrogen.. 6'11 6&57 6'54 6'69 6'40 Oxygen.. 4898 49-09 49-00 49'15 49'37 Strecker.* rom maize. From horse-chestnuts. From wheat. From rye. Carbon.. 44-27 44-44 44'26 44-16 Hydrogen. 6'67 6'47 6'70 6-64 Oxygen.. 49-06 49.08 49'04 49.20 Strecker.* From From From From rice. dahlia-roots. unripe apples. unripe pears. Carbon.. 4469 44-13 44V10 44-14 Hydrogen.. 636 6-56' 6-57 6'75 Oxygen.. 4895 49'31 49'33'49-11. From potatoes. From arrow-root. From yams.a Berzelius. Gay Lussac & Thenard. Prout. Ortigosa, Carbon 44'250 43 55 44'40 44'2 Hydrogen. 6'674 6-77 6'18 6-5 Oxygen. 49'076 49'68 49'42 49'3 a The starch employed for the analyses, made by Strecker and Ortigosa, was prepared from the chemical laboratory at Giessen, from the respective seeds, bulbs, and fruits. NOTE (12,) p. 28. COMPOSITION OF GRAPE SUGAR. (STARCH SUGAR.) From grapes.a From starch.b From honey.c Calculated. De Saussure. Prout. C12H1114014. Carbon. 36-71 37-29' 36-36 36-80 Hydrogen. 678 6'84 7'09 7'01 Oxygen. 56'51 55'87 56'55 56-19 a Aml, de Chimie, XI., 381. b Ann. of Philosophy, VI., 426. c Philosoph. Trans. 1827, 373. APPENDIX.-ANALYTICAL EVIDENCE, 89 NOTE (13,) p. 29. COMPOSITION OF SUGAR OF MILK. Gay Lussac Calculated and Thenard. Prout. Brunn. Berzelius. Liebig.* C1'H1201.t Carbon 38'825 40'00 40'437 39'474 40'00 40-46 Hydrogen 7-341 6'66 6-711 7-167 6-73 6'61 Oxygen. 53-834 53-34 52'852 53'359 53.27 52'93 NOTE (14,) p. 29. COMPOSITION OF GUM. Gay Lussac Calculated. and Thenard. Goebel. Berzelils. C12tO11011. Carbon - 42-23 42'2 42'682 42'58 Hydrogen 6'93 6'6 6 374 6'37 Oxygen 50'84 51-2 50'944 51 05 NOTE (15,) p. 29. ANALYSIS OF OATS. (Boussingault.) a. 100 parts of oats contain of dry matter... 82'9 Ditto water... 17-1 100.0 100 parts of oats dried at 212 — 117-7 parts dried at the ordinary temperature. contain Carbon.. 50'7 Hydrogen.. 6-4 Oxygen. 36-7 Nitrogen. 2-2 Ashes. 4'0 100'0 Water.. 17'7 Oats dried in the air 117'7 contain, in 100 parts, 1'867 of nitrogen. a Ann. de Chimie et de Phys,, LXXI., 130. ANALYSIS OF HAY. 100 parts of hay dried in the air contain 86 of dry matter, 14 of water. 100 100 parts of hay dried at 2120= 116'2 parts dried in air, contain Carbon.. 458 Hydrogen.. 50 Oxygen. 38'7 Nitrogen.. 15 Ashes 90 100-0 16'2 water, 1-16-2 hay dried in the air. 100'0 of hay dried at the ordinary temperature contain 1'29 of nitrogen. 240 oz. of such hay=15 lbs. contain.. 3'095 oz. of nitrogen. 72 oz. of oats — 4t lbs. contain. 1,34 ditto Total... 4'435 ditto NOTE (16,) a, p. 30. AMOUNT OF CARBON IN FLESH AND IN STARCH. 100 parts of starch contain 44 of carbon; therefore, 64 oz. (4 lbs.) contain 28-16 oz. of carbon. 100 parts of fresh meat contain 13-6 of carbon (see Note III.;) hence 240 oz. (15 lbs.) contain 32'64 oz. of carbon.* * By an error in calculation in the original, the amount of carbon in 15 lbs. of meat is stated to be 27 64 oz. It follows, that the carbon of 4 lbs. of starch is not equal, as stated in the text, to that of 15 lbs. of flesh, but to that of 13 lbs. This difference, however, is not sufficient to affect the argu. ment at p. 32.-EDITOR. 12 HI 90 A NIMAL CHEMISTRY. NOTE (16,) b, p. 32. COMPOSITION OF Hog's Lard. Mutton fat. Human fat, Chevreul. a Carbon... 79-098 78'996 79'000 Hydrogen-,. 11146 11-700 11-416 Oxygen... 9-756 9'304 9584 a Recherches Chim., sur les Corps Gras. Paris., 1823. NOTE (17,) p. 32 COMPOSITION OF CANE SUGAR. According to Berzelius. Prout. W. Crum. Liebig. Gay Lussac Calculated & Thenard. C12HI1O01 Carbon 42-225 42-86 42 14 42'301 42'47 42'58 Hydrogen 6'600 6'35 6-42 6-384 6'90 6-37 Oxygen 51'175 50'79 51'44 51-315 50-63 51'05 Fol the composition of gum and of starch, see Notes (14) and (11),NOTE (18,) p. 32. COMPOSITION OF CHOLESTERINE. According to Chevreul. a Couerbe.b Marchand. Calculated C36H320. Carbon. 85-095 84-895 84'90 84-641 Hydrogen. 11-880 12-099 12-00 12-282 Oxygen.. 3025 3'006 3410 3'077 a Recherches sur les Corps Gras, p. 185. b Ann. de Ch. et de Phys. LVI., p. 164. NOTE (19,) p. 33. THE PRODUCTION OF WAX FROM SUGAR.* As soon as the bees have filled their stomach, or what is called the honey bladder, with honey, and cannot deposit it for want of cells, the honey passes gradually in large quantity into the intestinal canal, where it is digested. The greater part is expelled as excre ment; the rest enters the fluids of the bee. In consequence of this great flow of juices a fatty substance is produced, which oozes out on the eight spots formerly mentioned, which occur on the four lower scales of the abdominal rings, and soon hardens into laminie of wax.' On the o:her hand, when the'bees candeposit their honey, only so much enters the intestinal canal as is necessary for their support. The honey bladder need not be filled with honey longer than forty hours in order to bring to maturity, on the eight spots, eight laminae of wax, so that the latter fall off. I made the experiment of giving to bees, which I had enclosed in a box with their queen about the end of September, dissolved sugar candy instead of honey. Out of this food laminge of wax were formed; but these would not separate and fall off readily, so that the mass, which continued to ooze out, remained, in most of the bees, hanging to the upper laminae: and the laminae of wax became as thick as four under ordinary circumstances. The abdominal scales of the bees were, by means of the wax, distinctly raised, so that the waxen laminie projected between them. On examination, I found that these thick laminie, which under the microscope exhibited several lamelle, had a sloping surface downwards near the head, and upwards in the vicinity of the tail. The first waxen laminie, therefore, must have been pushed downwards by the second, because, where the abdominal scales are attached to the skin, there is no space for two laminie, the second by the third, and thus the inclined surfaces on the sides of the thick lamince had been produced. I saw distinctly from this, that the first formed laminae are detached by those which followed. The sugar had been. converted into wax by the bees, but it would seem that there was some imperfection in the process, as the laminue did not fall off, but adhered to the succeeding ones. In order to produce wax in the manner described, the bees require no pollen, but only honey. I have placed, even in October, bees in an empty hive, and fed them with honey; they soon formed comb, although the weather was such that they could not leave the hive. I cannot, therefore, believe that pollen furnishes food for the bees, but I think they only swallow it, in order, by mixing it with honey and water, to prepare the liquid food for the grubs. Besides, bees often starve in April, -when their stock of honey is consumed, and when they can obtain in the fields abundance of pollen, but no honey. * From F. W. Gundlach's Natural History of Bees, p. 115. Cassel, 1842 We are acquainted with no more beautiful or convincing proof of the formation of fatty matter from sugar than the following process of the manufacture of -wax by the bees, as taken from observation. APPENDIX-ANALYTICAL EVIDENCE. 91 When pressed-by hunger they tear the nymphse out of the cells, and gnaw them in order to support life by the sweet juice which they contain. But, if in this condition they are not artificially fed, or if the fields do not soon yield their proper food, they die in the course of a few days. Now, if the pollen were really nourishment for bees, they ought to be able to support life on it, mixed with water. Bees never build honeycom.b unless they have a queen, or are provided with young out of which they can educate a queen. But if bees be shut up in a hive without a queen, and fed with honey, we can perceive in forty-eight hours that they have lamine of wax on their scales, and that some have even separated. The building of cells is therefore voiuntary, and dependent on certain conditions, but the oozing out of wax is involuntary. One might suppose that a large proportion of _these laminse must be lost, since the bees may allow them to fall off, out of the hive as well as in it; but the Creator has wisely provided against sucha. loss. If we give to bees engaged in building cells honey in a flat dish, and cover the dish with perforated paper, that the bees may not be entangled in the honey, we shall find, after a day, that the honey has disappeared, and that a large number of laminve are lyIng on the paper. It would appear as if the bees, which xaave carried off the'honey, had let fall the scales; but it'is not so. For, if above the paper we lay two small rods, and on' these.a board, overhanging the dish on every side, so that the bees can creep under the board and obtain the honey, we shall find next day the honey gone, but no laminae on the paper; while laminm will be found in abundance on the board above. The bees, therefore, which go for and bring the honey, do not let fall the laminae of wax, but only those bees which remain hanging,to the top of the hive. Repeated experiments of this kind have convinced me that the bees, as soon as their laminae of wax are mature, return to the hive and remain at rest, just as caterpillars do, when about to change. In a swarm that is actively employed in building we may see thousands of bees hanging idly at the top of the hive. These are all bees whose laminas of wax are about to separate. When they have fallen off, the activity of the bee revives, and Its place is occupied for the same purpose by another. (From page. 28 of the same work.)'In order to ascertain how much honey bees require to form wax, and how often, in a swarm engaged in building, the laminge attain maturity and fall off, I made the following experiment, which appears to me not uninteiesting.; On the 29tn of August, 1841, at a time when the bees could obtain in this district no farther supply of honey from the fields, I emptied a small hive, placed the bees in a small wooden hive, having, first selected the queen bee, and shut her up in a box, furnished with wires, which I placed in the only door of the hive, so that no embryoes could enter the cells. I then placed the hive in a window, that I might be able to watch it. At 6 P. M. I gave the bees 6 oz. of honey run from the closed cells, which had thus the exact consistence of freshly made honey. This had disappeared next morning. In the evening of the 30th I gave the bees 6 oz. more, which, in like manner, was removed by the next morning; but already some laminm of wax were seen lying on the paper with which the honey was covered. On the 31st August and the 1st September the bees had in the evening 10 oz., and on the 3d of September in the evening 7 oz.; in all, therefore, 1 lb. 13 oz. of honey, which had run cold out of cells which the bees had already closed. On the 5th of September I stupified the bees, by: means of puff-ball and counted them. Their number was 2,765, and they weighed 10 oz. I next weighed the hive, the combs of which were well filled with honey, but the cells not yet closed; noted theweight, and then allowed the honey to be carried off by a strong swarm of bees. This was completely effected in a few hours. I now weigohed it a second time, and found it 12 oz. lighter; consequently the bees still had in the hive 12 oz. of the 29 oz. of honey given to them. I next extracted the combs, and found that their weight was'- of an ounce. I then placed the bees in another box, provided with empty combs, and fed them with the same honey'as before. In the first few days they lost daily rather more than 1 oz. in weight, and afterwards half an ounce daily, which was owing to the circumstance, that from the digestion of so much honey, their intestinal canal was loaded with excrements; for 1,170 bees, in autumn, when they have been but a short time confined to the hive, weigh 4 oz.; consequently 2,765 bees should weigh 9 oz. But they actually weighed 10 oz., and therefore had within them I oz. of excrement, for their honey bladders were empty.- During the night the weight of the box did not diminish at all, because the small quantity of honey the bees had deposited in the cells, having already the proper consistence, could not lose weight by evaporation, and because the bees could not then get rid of their excrements. For this reason, the loss of weight occurred always during the day. If, then, the bees, in seven days, required 3A oz. of honey to support and nourish their bodies, they must have consumed 131 oz. of honey in forming { of an ounce of wax; and consequently, to form 1 lb. of wax, 20 lbs. of honey are required. This is the reason why the strongest swarms in the best honey seasons, when other hives, that have no occasion to build, often gain in one day 3 or 4 lbs. in weight, hardly become heavier, although their activity is boundless. All that' they gain is expended in making wax. 92 ANIMAL CHEMISTRY. This is a hint for those who keep bees, to limit the building of comb. Cnauf has already recommended this, although he was not acquainted with the true relations of the subject. From 1 oz. of wax, bees can build cells enough to contain 1 lb. of honey. 100 laminre of wax weigh 0'024 gramme (rather more than ~ of a grain,) consequently, 1 kilogramme (=- 15,360 grains) will contain 4,166,666 laminae. Hence, i of an ounce will contain 81,367 laminae. Now this quantity was produced by 2,765 bees in six days; so that the bee requires for the formation of its 8. lamina (one crop) about thirty-eight hours, which agrees very well with my observations. The laminre, when formed, are as white as bleached wax. The cells also, at first, are quite white, but they are coloured yellow by the honey, and still more by the pollen. When the cold weather comes on, the bees retire to the hive under the honey, and live on the stock they have accumulated. P. 54. Many believe that bees are hybernating animals; but the opinion is quite erroneous. They are lively throughout the winter; and the' hive is always warm in consequence of the heat which they generate. The more numerous the bees in a hive, the more heat is developed; and hence strong hives can resist the most intense cold. It once happened that I forgot to remove from the door, which was unusually large, of a hive in winter, a perforated plate of tinned iron, which I'had fastened over the opening to diminish the heat in July; and yet this hive came well through the winter, although the cold was very severe, having been for several days so low as 0~. But I had added to this hive the bees of two other hives! When the cold is very intense, the bees begin to hum. By this means respiration is accelerated and the developement of heat increased. If, in summer, bees without a queen are shut up in a glass box, they become uneasy and begin to hum. So much heat is by this means developed, that the plates of glass become quite hot. If the door be not opened in this case, or if air be not admitted, and if the glass be not cooled by the aid of water, the bees are soon suffocated. COMPOSITION OF BEES" WAX. Gay Lussac Calculated and Thenard.a De Saussure.b Oppermann.c Ettling.d Hess.e C20H200. Carbon. 81-784 81'607 81-291 81-15 81-52 81-38 Hydrogen. 12'672 13.859 14-073 13-75 13'23 13'28 Oxygen. 5'544 4'534 4-636 5'09 5'25 5'34 a Traite de Chimie, par M. Thenard, 6me. Ed. IV., 477. b Ann. de Ch. et de Phys. XIII., 310. c Ibid. XLIX., 224. d Annal. der Pharm., II., 267. e Ibid. XXVII., 6. NOTE (21) a, p. 36. COMPOSITION OF HYDRATED CYANURIC ACID, OR HYDRATED CYANIC ACID, AN-) OF CYAMBELIDE, IN 100 PARTS, ACCORDING TO THE ANALYSIS OF WOHLER AND LIEBIG.2a Cyanuric acid, cyanic acid, cyamelide. Carbon. 28'19. Hydrogen....... 2'30 Nitrogen....... 3263 Oxygen....... 36'87 a Poggendorff's Annalen, XX., 375 et seq. NOTE (21) b. p. 36. COMPOSITION OF ALDEHYDE, METALDEHYDE, AND ELALDEHYDE.a Aldehyde. Metaldehyde. Elaldehyde. Calculated Liebig.* Fehling.* C4H402. Carbon. 55'024 54'511 54-620 54-467 55'024 Hydrogen. 8983 9'054 9-248 9'075 8'983 Oxygen. 35993 36'435 36'132 360458 35'993 a Ann. der Pharm., XIV., 142, und XXVII., 319. NOTE (22,) p. 37. COMPOSITION OF PROTEINE. From the crystalline lens. From albumen, From fibrine. Scherer.a Carbon. 55'300 55 100 54-848 Hydrogen.. 6-940 7'055 6'959 Nitrogen. 16216 15'966 15-847 Oxygen.. 21"544 21-819 22-346 a Ann. der Chem. und Pharm., XL., 43. APPENDIX.-ANALYTICAL EVIDENCE. 93 Scherer.a,-. Calculated From hair. From horn. C48H36N6014. Carbon 54-746 55-150 55-408 54-291 55-742 Hydrogen.. 7-129 7'197 7-238 7-082 6-827 Nitrogen.. 1-727 15-727 15'593 15'593 16-143 Oxygen.. 22-398 21-926 21-761 23'034 21'228 a Ann. der Chem. und Pharm., XL., 43. From vegetable albumen. From fibrine. From albumen. From cheese. Mulder.a Carbon 54-99 55-44 55-30 55 159'Hydrogen.... 687 8.95 6*94. 7.176 Nitrogen.. 15-66 16'05 16'02 15'857 Oxygen.. 22'48 21'56 21'74 21'808 a Ann. de Pharm., XXVIII., 75. NOTE (23,) p. 37. COMPOSITION OF TIHE ALBUMEN OF THE YOLCK AND OF THE WHITE OF THE 3EGlG.a From the yolk. From the white. Jones.* Scherer.* I. IL. Carbon.. 5372 53'45 55'000 Hydrogen.. 7-55 766 7'073 Nitrogen.. 13-60 13-34 15-920 Oxygen Sulphur. 2513 25'55 22'007 Phosphorus a Ann, der Chem, und Pharm. XL., 36, ibid. 67. NOTE (24,) p. 38. COMPOSITION OF LACTIC ACID. C6H505. Carbon... 44'90 Hydrogen.. 611 Oxygen.... 48-99 NOTE (25,) p. 39. GAS FROM THE ABDOMEN OF COWS AFTER EATING CLOVER TO EXCESS, OBTAINED BY PUNCTURE. a Examined by Lameyran and Fremy. b By Vogel. c By Pfliige. Air. Carbonic acid. Inflammable gas. Sulphuretted hydrogen. a 5 5 15.80 Vol. in 100 Vol. b 25 - 27 48 - c- - 60 40 c- - 20 80 - NOTE (26,) p. 40. MAGENDIE FOUND IN THE STOMACH AND INTESTINES OF EXECUTED CRIMINALS: a In the case of an individual who had taken food in moderation one hour previous to death; b, in the case of one who had done so two hours previously; and c, in the case of a third, who had done so four hours previous to execution. 100 Volumes of the gas contained: Oxygen. Nitrogen. Carbonic acid. Inflammable gas. (From the stomach 11 00 Vol. 71-45 14-00 3'55 ta - small intestines 00'00 20'03 24,'39 55-53 large intestines 00'00 51'03 43'50 5'47 (From the stomach 00'00 00'00 00'00 00'00 hb _ small intestines 00'00 8'85 40'00 51-15 large intestines 00'00 18'40 70'00 11'60 (From the stomach 00'00 00'00 00'00 00'00 c - - small intestines 00'00 66'60 25'00' 840 large intestines 00'00. 4596 42'86 11'18 94 ANIMAL CHEMISTRY. NOTE (27,) referred to in NOTE (7,) p. 21. COMPOSITION OF ANIMAL ALBUMEiN AND FIBRINE, AND OF THE DIFFERENT TISSUES OF THE BODY. 1. ALBUMEN. From the serum of blood. From eggs. From yolk of egg. Scherer.*a Jones.*b I. II. ITI. IV. V. VI. Carbon. 53'850 55'461 55'097 55'000 53-72 53'45 Hydrogen 6-983 7-201 6'880 7'073 7.55 7-66 Nitrogen. 15'673 15'673 15-681 15'920 13-60 13-34 Oxygen Sulphur 5 23-494 21-655 22-342 22'007 -25-13 25-55 Phosphorus 5 a Ann. der Chem. und Pharm., XL., 36. b Ibid. 67. Jones.* Scherer.* From albumen From From congestive From fluid of brain. hydrocele. abscess. From pus. of dropsy VII. VIII. IX. X. Xi. XII.Carbon.. 55'50 54'921 54'757 54'663 54-101 54-302 ~Hydrogen.. 7.19 7077 7-177 7-022 6'947 7-176 Nitrogen. 16-31 15-465 15-848 15'839 15-660 15-717 Oxygen ) Sulphur >. 2100 22'537 22'224 22-476 23-292 22805 Phosphorus.) Mulder.a Carbon... 5484 Hydrogen 7..09 Nitrogen.. 15'83 Oxygen....21-23 Sulphur.... 068 Phosphorus. 033 a Ann. der Pharm. XXVIII., 74. 2. FIBRINE. Scherer.*a I.. III. IV. V. VI. VI. I. Carbon 53-671 54.454 55'002 54-967 53-571 54'686 54-844 Hydrogen 6-878 7'069 7-216 6-867 6-895 6-835 7.219 Nitrogen 15'763 15-762 15.817 15-913 15-720 15'720 16'065 Oxygen Sulphur > 23-688 22-715 21-965 22-244 23-814 22'759 21-872 Phosphorus a Ann. der Chem. und Pharm., XL., 33. Carbon.... 5456. Hydrogen.... 690 Nitrogen.... 15.72 Oxygen.... 2213 Sulphur.... 033 Phosphorus.o. 0-36 a Ann. der Chem. und Pharm., XXVIII., 74. 3. GELATINOUS TISSUES.Scherer.*a Isinglass. Tendons of the Tunica Calculated. calf's foot. sclerotica. C48H41N7J018 Carbon 50-557 49-563 50'960 50'774 50-995 50'207 Hydrogen 6-903 7-148 7'188 7152 7'075 7'001 Nitrogen 18'790 18'470 18-320 18'320 18'723 18 170 Oxygen 23 750 24.819 23'532 23'754 23'207 24'622 a Ann. der Chem. und Pharm., XL., 46. Mulder. Carbon. e. 50'048 50'048 Hydrogen... 6477 6643 Nitrogen... 18350 18-388 Oxygen.., 25-125 24'921 APPENDIX. —ANALYTICAL EVIDENCE. 95 4. TIsurES CONTAINING CHONDRINE. Scherer.*a r,artilages of the Calculated ribs of the calf. Cornea. C48H40N6020 Mulder. Carbon 49-496 50895 49-522 50-745 50'607 Hydrogen 7'133 6'962 7'097 6'904 6-578 Nitrogen 41'908 14'908 14-399 14'692 14-437 Oxygen 28-463 27'235 28'982 27'659 28'378 a Ann. der Chem. und Pharm., XL., 49. 5. COMPOSITION OF THE MIDDLE MEMBRANE OF ARTERIES. Scherer.*a ___________.....,________ _ Calculated I. I. C48H38N6016 Carbon 53'750 53 393 53'91 Hydrogen 7'079 6-973 6'96 Nitrogen 15'360 15'360 15'60 Oxygen 23'811 24-274 23'53 a Ann. der Chem. und Pharm., XL., 51. 6. COMPOSITION OF HORNY TISSUES. Scherer.*a External skin Hair of Hair of the head. of the sole of the foot. the beard. Fair. Brown. Black. Carbon 51-036 50752 51'529 50652 49'345 50622 49935 Hydrogen 6-801 6-761 6'687 6'769 6'576 6-613 6-631 Nitrogen 17-225 17-225 17-936 17'936 17'936 17'936 17'936 Oxy~gen } 24'938 25'262 23'848 24'643 26-143 24 829 25-498 Sulphur ~ Scherer.*a Calculated Buffalo horn. Nails. Wool. C48H391N"017 Carbon 51-990 51-162 51'620 51-540 51-089 50'653 51-718 Hydrogen 6'717 6'597 6'754 6'779 6'824 7'029 6'860 Nitrogen 17'284 17-284 17'284 17-284 16'901 17'710 17-469 Oxygen t 24-009 24-957 24 342) 24-397 25-186 24-608 23'953 Sulphur a Ann. der Chem. und Pharm., XL., 53. The composition of the membrane lining the interior of the shell of the egg approaches closely to that of horn. According to Scherer, it contains Scherer.*a Carbon..50674 Hydrogen. 6608 Nitrogen.16761 Oxygen - Oxygen t..... 25'958 Sulphur 2 a Ann. der Chem. und Pharm., XL., 60. The composition of feathers is also nearly the same as that of horn. Scherer.*a Beard of the Quillof the Calculated feather. feather. C48H39N7016. Carbon.. 50434 52-427 52'457 Hydrogen.. 7110 7-213 6'958 Nitrogen.. 17682 17'893 17'719 Oxygen... 24774 22'467 22'866 a Ann. der Chem. und Pharm., XL., 61. The analysis here given of the beard of feathers agrees closely with that of horn, while that of the quill is more accurately represented by the attached formula, which differs from that of horn by 1 eq. of oxygen only. 7. COMPOSITION OF THE PIGMENTUM NIGPtUM OCULI. Scherer.*a Carbon..273 58673 57908 Hydrogen... 5973 5'962 5-817 Nitrogen... 13-768 13'768 13-768 Oxygen... 21'986 21-598 22'507 a Ann. der Chem. und Pharm., XL., 63. '95 A ANIMAL CHEMISTRY. NOTE (28,) p. 44. According to the analyses of Playfair and Bceckinann, 0-452 parts of dry muscular flesh gave 0'836 of carbonic acid. 0-407. 0-279 of water. 0-242 0450 of carb. acid and 0-164 water. 0191 0-360. 0'130 0-305 of dried blood gave 0'575 carbonic acid and 0-202 of water. o0214 0.402 0138 1-471 of dried blood, when calcined, left 0-065 of ashes=4-442 pr. cent. The dried flesh was found to contain of ashes 4-23 pr. cent. The nitrogen was found to be to the carbon as 1 to 8 in equivalents. Hence Flesh (beef.) Ox-blood. Blood. Playfair. Bceckmann. Playfair. Bcrckmann. Mean of 2 analyses. Carbon 51-83 51'89 51-95 51-96 51-96 Hydrogen 7-57 7'59 7-17 7-33 7-25 Nitrogen 15'01. 15-05 15-07 15-08 15-07 Oxygen 21-37 21-24 21-39 21-21 21-30 Ashes 4-23 4-23 4-42 4-42 4-42 Deducting the ashes, or inorganic matter, the composition of the organic part is, Carbon.. 54 12 54-18 54-19 54-20 Hydrogen 7-89 7'93 7-48 7-65 Nitrogen.. 15-67 15-71 15-72'15-73 Oxygen... 22-32 22-18 22-31 22-12 This corresponds to the formula C48... 54-62 H39.... e 7-24 N6.. 15-81 015.. ~.. 22-33 NOTE (29,) p. 44. COMPOSITION OF CHOLEIC ACID. a Calculated Demargay. Dumas. C761166N2022, Carbon. 63-707 63-5 63-24 Hydrogen 8-821 9-3 8-97 Nitrogen. 3-255 3'3 3-86 Oxygen.. 24.217 23-9 23-95 a Ann. der Pharm., XXVII., 284 and 293. NOTE (30,) p. 44. COMPOSITION OF TAURINE AND OF CHOLOIDIC ACID. I. TAURINE. a Calculated. Demargay.* Dumas. C4H7NO!0 Carbon.. 19-24 19-26 19-48 Hydrogen.. 5-78 5-66 5-57 Nitrogen.. 11-29 11.19 11-27 Oxygen.. 63-69 63-89 63-68 a Ann. der Pharm., XXVII., 287 and 292. 2. CHOLOIDIC ACID. a DemarSay.* A Dumas. Calculated. C36II56012 Carbon,. 73-301 73-522 73-3 74-4 Hydrogen 9-511 9-577 9-7' 94 Oxygen.. 17-188 16-901 17-0 16'2 a Ann. der Pharm., XXVII., 289 and 293. In reference to the researches of Demargay on the bile I would make the following observations. The matter to which I have given the name of choleic acid is the bile itself separated from the inorganic constituents (salts, soda, &c.) which it contains. By the action of' subacetate of lead aided by ammonia, all the organic constituents of the bile are made to unite with oxide of lead, with which they form an insoluble, resinous precipitate. The APPENDIX.-ANALYTICAL EVIDENCE. 97 substance here combined with oxide of lead contains all the carbon and nitrogen of the bile. The substance which I have named choloidic acid is that which is obtained, when the bile, purified by alcohol from the substances insoluble in that fluid, is boiled for some time with an excess of muriatic acid. It contains all the carbon and hydrogen of the bile, except those portion which have separated in the form of taurine and ammonia. The cholic acid contains the elements of bile, minus-those of carbonate of ammonia. These three compounds, therefore, contain the products of the metamorphosis of the entire bile; their formule express the amount of the elements of the constituents of the bile. No one of them exists ready formed in the bile in' the shape in which we obtain it; their elements are combined in a different way from that in which they were united in the bile; but the way in which these elements are arranged has not the slightest inflence on the determination by analysis of the relative proportions of the elements. In the formule themselves, therefore, is involved no hypothesis; they are simply expressions of the results of analysis. It signifies nothing that the choleic or choloidic acids may be composed of several compounds united together. No matter how many such they may contain, the relative proportions of all the elements taken together is expressed by the formula which is derived from the analysis. The study of the products which are produced from the bile by the action of the atmosphere, or of chemical re-agents, may be of importance in reference to certain pathological conditions; but except as concerns the general character of the bile, the knowledge of these products is of no value to the physiologist; it is only a burthen which impedes his progress. It cannot be maintained of any one of the 38 or 40 substances, into which the bile has been divided or split up, that it exists ready formed in the healthy secretion; on the contrary,-we know-with certainty that most of them are mere products of the action of the re-agents' which are made to act on the bile. The bile contains soda; but it is a most remarkable and singular compound of soda. When we cause that part of the bile which dissolves in alcohol (which contains nearly all the organic part) to combine with oxide of lead, thus separating the soda, and then remove the oxide of lead, we obtain a substance, choleic acid, which, when placed in contact with soda, forms a compound similar to bile in its taste; but it is no longer bile; for bile may be mixed with organic acids, nay, even with dilute mineral acids, without becoming turbid or yielding a precipitate; while the new compound, choleate of soda, is decomposed by the feeblest acids, the whole of the choleic acid being separated. Hence, bile cannot be considered, in any sense, as choleate of soda. Further, it may be asked, in what form are the cholesterine, and stearic, and margaric acids, which are found in bile, contained in that fluid? Cholesterine is -insoluble in water, and not saponifiable by alkalies; and if the two fatty acids just named were really present in the bile as soaps of soda, they would be instantly separated by other acids. Yet diluted acids cause no such separation of stearic and margaric acids in bile. It is possible that, in the course of new and repeated investigations, the composition of the substances obtained from bile may be found different from that which has been given in our analytical developement of this subject. But this, if it should happen, can have but little effect on our formula; if the relative proportions of carbon and nitrogen be not changed, the differences will be confined to the proportions of oxygen and hydrogen. In that case it will be necessary for the developement of our views in formulke, only to assume that more water and oxygen, or less water and oxygen, have taken a share in the metamorphosis of the tissues; but the truth of the developement of the process itself will not be by this means affected. NOTE (31,) p. 44. COMPOSITION OF CHOLIC ACID. a Dumas. Calculated C74H60018., Carbon.... 68'5. -.. 689 Hydrogen... 9.7... 9.2 Oxygen.. 21.8... 21.9 a Ann. der Pharm. XXVII., 295. NOTE (32,) p. 45. COMPOSITION OF THE CHIEF CONSTITUENTS OF THE URINE OF MEN AND ANIMAL,. 1. URIC ACID. Liebig.*a Mitsclerlich.b Calculated C10I14N405. Carbon.. 36083 35-82 36-00 Hydrogen.. 2441 2'38 236 Nitrogen.. 33361 34 60 33.37 Oxygen..28.126 27'20 28-27 a Ann. der Pharm., X.. 47. b Pogrendorff's Ann., XXXIII., 335. 13 98 ANIMAL CHEMISTRY. 2. ALLOXAN. a A PRODUCT OF THE OXIDATION OF URIC ACID. Woehler and Liebig.* Calculated C8H4N2010. Carbon...3038 30'18 30'34 Hydrogen. 2-57 2-48 2-47 Nitrogen.. 17.96 17-96 17-55 Oxygen.. 4909 49'38 49.64 a Ann. der Pharm., XXVI., 260. 3. UREA. Prout. a Wcehler and Liebig. b Calculated C2H4N202 Carbon. 19-99' 20'02 20'192 Hydrogen. 665 6-71 6-595 Nitrogen.. 46-65 46-73 46'782 Oxygen. 26-63 26'54 26'425 a Thompson's Annals., XT., 352. b Poggend. Ann., XX., 375. 4. CRYSTALLIZED HIPPURIC ACID. Liebig.* a Dumas. b Mitscherlich. c Calculated C18H8N05. Carbon 60-742 60-5 60'63 60'76 Hydrogen 4-959 4'9 4-98 4'92 Nitrogen 7-816 7-7 7'90 7'82 Oxygen 26'483 26-9- 26'49 26-50 a Ann. der Pharm., XII., 20. b Ann. de Ch. et de Phys., LVII., 327. c Poggend. Ann., XXXIII., 335. 5. ALLANTOINE. a -Washler and Liebig.* Calculated C8116N406 Carbon... 30.60 30'66 Hydrogen... 383 3'75 Nitrogen... 35'45 35'50 Oxygen... 30-12 30'09 a Ann. der Pharm., XXVI., 215. 6. URIC ON XANTHIC OXIDE. a Woehler and Liebig.* Calculated C5H12N202. Carbon. 3928 39'86 Hydrogen... 295 2'60 Nitrogen... 3635 37'72 Oxygen.... 21-24 20'82 a Ann. der Pharm., XXVI., 344. 7. CYSTJC OXIDE, a Thaulow.* Calculated C6H6N04S4. Carbon.. 3001 30-31 Hydrogen.. 510 494 Nitrogen. 11l00 11'70 Oxygen. 28'38 26'47 Ss phur.. 25'51 26-58 a Ann der Pharm., XXVII., 200. APPENDIX.-ANALYTICAL EVIDENCE. 99 The cystic oxide is distinguished from all the other concretions occurring in the urinary bladder by the sulphur it contains. It can be shown with certainty, that the sulphur is present neither in the oxidized state, nor in combination with cyanogen; and in regard to its origin the remark is not without interest, that four atoms of cystic oxide contain the elements of uric acid; benzoic acid, sulphuretted hydrogen, and water; all of which are substances, the occurrence of which. in the body is beyond all doubt 1 atom uric acid... C10N4H406 1 atom benzoic acid Cl~ H5O3 8 atoms sulphuret- H8 S ted hydrogen.... -7 atoms water..... H707 4 atoms cystic oxide = C24N4H24016S8 =4 (C6NH604S2). An excellent method of detecting the presence of cystic oxide in calculi or gravel is the following: The calculus is dissolved in a strong solution of caustic potash, and to the solution is added so much of a solution of acetate of lead, that all the oxide of lead is retained in solution. When this mixture is boiled there is formed a black precipitate of sulphuret of lead, which gives to the liquid the aspect of ink. Abundance of ammonia is also disengaged; and the alkaline fluid is found to contain, among other products, oxalic acid. NOTE (33,) p. 45. COMPOSITION OF OXALIC, OXALURIC, AND PARABANIC ACIDS. 1. OXALIC ACID (hydrated.) Calculated Gay Lussac & Thenard. Berthollet. C' 03+HO Carbon.. 26566 25-13 26'66 Hydrogen.. 2745 3'09 2'22 Oxygen,.. 70'689 71-78 71'12 o2. OXALURIC ACID. a Wcehler and Liebig.* Calculated C6H4N208 Carbon.. 27600 27-318 27'59 Hydrogen. ~ 3-122 3-072 3'00 Nitrogen. 21'218 21-218 21-29 Oxygen. 48'060 48'392 48-12 a Ann. der Pharm., XXVI., 286. 3. PARABANIC ACID. a Wcehler and Liebig.* Carbon. 31-95' 31'940 31-91 Hydrogen. 209 1'876 1'73 Nitrogen. 2466 24'650 24-62 Oxygen. 41'30 41'534 41 74 a Ann. de Pharm., XXVI., 286. NOTE (34,) p. 45. COMPOSITION OF ROASTED FLESH. (1.) 0 307 of flesh gave 0-584 of carbonic acid and 0'206 of water. (2.) 0'255 do. 0'485 do. 0'181 do. (3.) 0-179 Tdo. 0'340 do. 0'125 do. Hence -- Flesh of roedeer(l.) Flesh of Beef(2.) Flesh of veal (3.) Baeckmann.* Playfair. Carbon.. 52-60 52'590 42-52 Hydrogen.. 7-45 7'886 7-87 Nitrogen. 15-23 15'214 14'70 Oxygen - 7 e. 24'72 24.310 24.91 Ashes 24 100 ANIMAL CHEMISTRY. NOTE (35,) p. 46. The formula C10I-I4N'18040, or C54H42N9020, gives, when reduced to 100 parts, C54..... 50'07 H42... 635 N9....... 19-32 020...... 2426 Compare this with the composition of gelatine, as given in Note (27) NOTE (37,) p. 49. COMPOSITION OF DITHOFELLIC ACID.a Calculated Ettling and Will.* Wcehler.* C4360ulated Carbon.. 7119 70-80 70-23 70-83 70'83 Hydrogen. 10'85 10-78 10-95 10'60 10:48 Oxygen.. 17-96 18-42 18'82 18'57 18'69 a Annalen der Chem. und Pharm., XXXIX., 242, and XLI., 154. NOTE (38,) p. 56. COMPOSITION OF SOLANINE FROM THE BUDS OF GERMINATING POTATOES. Blanchet. Carbon. 62'11 Hydrogen. 8'92 Nitrogen 164 Oxygen..... 27-33 a Ann. der Pharm., VII., 150. NOTE (39,) p. 56. COMPOSITION OF PICROTOXINE. a Francis.* Carbon. e.. 60'26 Hydrogen.... 5'70 Nitrogen.... 130 Oxygen.. 32'74 a In another analysis. M. Francis obtained 0'75 per cent. of nitrogen. The picrotoxine employed for these analyses was partly obtained from the manufactory of M. Merck, in Darmstadt, and was partly prepared by M. Francis himself; it was perfectly white, and beautifully crystallized. Reg. nault, as is well known, found no nitrogen in this compound. NOTE (40,) p. 56. COMPOSITION OF QUININE. Liebig.* Calculated C201112NO2. Carbon.... 75-76 74'39 Hydrogen.. 752 7525 Nitrogen.. 8-11 8'52 Oxygen.... 862 9-64 NOTE (41,) p. 156. COMPOSITION OF MORPHIA. a Calculated Liebig.* Regnault. C35H20N06 Carbon... 72'340 72'87 72'41 72-28 Hydrogen.. 6366 6'86 6'84 6-74 Nitrogen... 4'995 5'01 5'01 4-80 Oxygen. 16-299 15'26 15-74 16-18 a Ann, der Pharm., XXVI,, 23. APPENDIX.-ANALYTICAL EVIDENCE. 101 NOTE (42,) p. 156. COMPOSITION 01F CAFFEINE, THEINE, GUARANINE, THEOBROMINE, AND ASPARAGIliE. Caffeine, a Theine. b Guaranine. c Calculated Pfaff and Liebig.* Jobst. Martius. C8115N202 Carbon.. 4977 50'101 49'679 49'798 Hydrogen. 533 5'214 5'139 5'082 Nitrogen.. 2878 29-009 29-180 28'832 Oxygen.. 1612 15'676 16'002 16-288 a Ann. der Pharm., I., 17. b Ann. der Pharm., XXV., 63.: c Ann. der Pharm., XXVI., 95, Guaranine is the name given to the crystallized principle of the guarana officinalis, till it wvas shown to be identical with caffeine and theine, as the above analyses demonstrate, COMPOSITION. OF THEOBROMINE. a Calculated Woskreseusky. C9H5N302 Carbon 7. 4721 46:97 46&71 46-43 Hydrogen.. 4-53 4-61 4-52 4-20 Nitrogen. 3538 3538, 35'38 35'85 Oxygen.. 12'88 13-04 13-39 13-51 a Ann. der Chem. und Pharm., xli., 125. COMPOSITION OF &SPARAGINE. a lrebig. Calculated C8H8N206 + 2HO Carbon 8. 32'351 32'35 Hydrogen... 6'844 6'60 Nitrogen.. 18-734 18'73 Oxygen... 42021 42'32 a Ann. der Pharm., VII., 146. ON THE C(ONVERS1ON OF BENZOIC ACID INTO HIPPURIC ACID.% BY WILHELM KELLER (From the Annalen der Chemie und Pharmacie.) So early as in the edition of Berzelius' " Lehrbuch der Chemie,"' published in 1831, Professor Wihler had expressed the opinion, that benzoic acid, during digestion, was probably converted into hippuric acid. This opinion was founded on an experiment which he had made on the passage of benzoic acid into the urine. He found in the urine of a dog which had eaten half a drachm of benzoic acid with his food, an acid crystallizing in needle-shaped prisms, which had the general properties of benzoic acid, and which he then took for benzoic acid. (Tiedemann's Zeitschrift fur Physiologie, i. 142.) These crystals were obviously hippuric acid, as plainly appears from the statements, that they had the aspect of nitre, and, when sublimed, left a residue of carbon. But at that time hippuric acid was not yet discovered; and it is well known that, till 1829, when these acids were first distinguished from each other by Liebig, it was uniformly confounded with benzoic acid. The recently published statement of A. Ure, that he actually found hippuric acid in the urine of a patient who had taken benzoic acid, recalled this relation. so remarkable in a physiological point of view, and induced me to undertake the following experiments, which, at the suggestion of Professor Wohler, I made on myself. The supposed conversion of benzoic acid into hippuric acid has, by these experiments, been unequivocally established. I took, in the evening before bed-time, about thirty-two grains of pure benzoic acid in syrup. During the night I perspired strongly, which was probably an effect of the acid, as in general I am with great difficulty made to transpire profusely. I could perceive no other effect, even when, next day, I took, the same dose three times; indeed, even the perspiration did not again occur. The urine passed in the morning had anhncommonly strong acid reaction, even after it had been evaporated, and had stood for twelve hours. It deposited only the usual sediment of earthy salts. But when it was mixed with muriatic acid, and allowed to stand, * To the evidence produced by A. Ure, of the conversion of benzoic acid into hippuric acid in the numan body, M. Keller has added some very decisive proofs, which I append to this work on account of their physiological importance. The experiments of M. Keller were made in the laboratory of Professor Wihler, at Gottingen; and they place beyond all doubt the fact that a non-azotized substance taken in the food can take a share, by means of its elements, in the act of transformation of the animal tissues, and in the formation of a secretion. This fact throws a clear light on the mode of action of the greater number of remedies; and if the influence of caffeine on the formation of urea or uric acid should admit of being demonstrated in a similar way, we shall then possess the key to the action of quinine and of the other vegetable alkalies.-J. L. 102 ANIMAL CHEMISTRY. there were formed in it long prismatic, brownish crystals, in great quantity, which evea in this state, could not be taken for benzoic acid. Another portion, evaporated to the consistence of syrup, formed, when mixed with muriatic acid, a magma of crystalline scales. The crystalline mass was pressed, dissolved in hot water, treated with animal charcoal, and recrystallized. By this means the acid was obtained in colourless prisms, an inch in length. Their crystals were pure hippuric acid. When heated, they melted easily; and when exposed to a still stronger heat, the mass was carbonized, with a smell of oil of bitter almonds, while benzoic acid sublimed. To remove all doubts, I determined the proportion of carbon in the crystals, which I found to be 60-4 per cent. Crystallized hippuric acid, according to the formula C'1H8NNO5 HO, contains 60'67 per cent. of carbon; crystallized benzoic acid, on the other hand, contains 69-10 per cent. of carbon. As long as I continued to take benzoic acid, I was able easily to obtain hippuric acid in large quantity froin the urine; and since the benzoic acid seems so devoid of any injurious effect on the health, it would be easy in this way to supply one's self with large quantities of hippuric acid. It would only be necessary to engage a person to continue for some weeks this new species of manufacture. It was of importance to examine the urine which contained hippuric acid, in reference to the two normal chief constituents, urea and uric acid. Both were contained in it, and apparently in the same proportion as in the normal urine. The inspissated urine, after the hippuric acid had been separated by muriatic acid. yielded, on the addition of nitric acid, a large quantity of nitrate of urea. It had pre viously deposited a powder, the solution of which in nitric acid gave, when evaporated to dryness, the well-known purple colour characteristic of uric acid. This observation is opposed to the statement of Ure; and he is certainly too hasty in recommending benzoic acid as a remedy for the gouty and calculous concretions of uric acid. He seems to suppose that the uric acid has been employed in the conversion of benzoic acid into hippuric acid; but as his observations were made on a gouty patient, it may be supposed that the urine, even without the internal use of benzoic acid, would have been found to contain no uric acid. Finally, it is clear that the hippuric acid existed in the urine in combination with a base, because it only separated after the addition of an acid. THE zEND' INDEX. A. in the oxidation of blood, 45. Is found in the Acid, Acetic. Composition; and relation to that human urine after benzoic acid has been adof aldehyde, 80, 81. ministered, 48, 101. May be derived from proAcid, Benzoic. Composition, and relation to that teine when acted on by oxygen and uric acid, of oil of bitter. almonds, 80, 81. Converted into 48. With starch and oxygen, it may produce hippuric acidin the human body, 48, 101. choleic and carbonic acids, 48. May be derived Acid, Carbonic. Is the form in which the in- from the oxidation of choleic acid, 49. spired oxygen and the carbon of the food are Acid, Hydrocyanic or Prussic. Its poisonous acgiven out, 14. Its formation in the body the tion explained, 80. chief source of animal heat, 15-16. Occurs Acid, Lithofellic. Its composition, 100. Probably combined with potash and soda, in the serum derived from the oxidation of choleic acid: is of the blood, 21. Formed by the action of the chief constituent of bezoar stones, 49. oxygen on the products of the metamorphosis Acid, Lactic. Its composition, 93. Its origin, of the tissues, 26. Its formation may also be 38. Does not exist in the healthy gastric connected with the production of fat from juice, 38. starch, 32-34. Generated by putrefaction of Acid, Margaric. Exists in bile, 97. food in the stomach of animals, 39. Also by Acid, Muriatic. Exists in the free state in the the fermentation of bad wine in man, when it gastric juice, 37, 38. Is derived from common causes death by penetrating into the lungs, 39. salt, 38, 52. Escapes through both skin and lungs, 39. Pro- Acid, Oxaluric. Analysis of, 99. duced, along with urea, by the oxidation of uric Acid, Parabanic. Analysis of, 99. acid, 45. Produced with several other corn- Acid, Phosphoric. Exists in the urine of the pounds, by the oxidation of blood, 45. May carnivora in considerable quantity, 30, 52. Its be formed. along with choleic acid, from hip- proportion very small in that of the graminipuric acid, starch and oxygen, 49. Also, along vora, 31. Derived from the phosphorus of the with choleic acid, urea, and ammonia, by the tissues, 30. It is retained in the body to form action of water and oxygen on starch and pro- bones and nervous matter, 31. teine, 49. Produced, along with fat and urea, Acid, Sulphuric. Exists in the urine of the carfrom proteine, by the action of water and oxy- nivora, 30, 52. Derived firom the sulphur of gen, in the absence of soda, 49. Combines the tissues, 30. with the compound of iron present. in venous Acid, Uric. Its composition, 98. Products of blood, and is given off when oxygen is ab- its oxidation, alloxan, carbonic acid, oxalic acid, sorbed, 78. Is absorbed by the serum of blood urea, &c., 45. Is probably derived, along with in all states, 78. choleic acid, by the action of oxygen and water Acid, Cerebric. Its composition, 57. Its pro- on blood or muscle, 44. Disappears almost enperties, 58. tirely in the system of man and of the higher Acid, Choleic. Represents the organic portion animals, 24, 41. Appears as calculus, when of the bile, -44. Its formula, 44. Its trans- there is a deficiency of oxygen, 44. Never formations, 42. Half its formula, added to that occurs in phthisical cases, 45. Yields mulberry of urate of ammonia, is equal to the formula of calculus when the quantity of oxygen is someblood + a little oxygen and water, 44. Pro- what increased, but only urea and carbonic acid duced in the oxidation of blood, 45. Views with a full supply of oxygen, 45. Uric acid which may be taken of its composition, 47. calculus promoted by the use of fat and of cerMay be formed by the action of oxygen and tain wines, 45. Unknown on the Rhine, 45. water on proteine and starch, 48. Products Uric acid and urea, how related to allantoine, of its oxidation, 49. Various ways in which. 46; to gelatine, 46. Forms the greater part it may be supposed to be formed in the body, of. the urine of serpents, 24. Yields, with the 51. Its composition, 96. Cannot be said to elements of proteine and oxygen, hippuric acid exist ready formed in the bile, 97. and urea, 48. How related to taurine, 49. Acid, Cholic. Its composition, 98. Derived Calculi of it never occur in wild carnivora, but from choleic acid, 44. Possible relation to often in men who use little animal food, 47. choleic acid, 47. Affinity, Chemical. Is the ultimate cause of the Acid, Choloidic. Its composition, 96. Derived vital phenomena, 13. Is active only in the from choleic acid, 44. Possible relation to case of contact, and depends much on the order choleic acid, 47. Possible relation to starch, 51. in which the particles are arranged, 62. Its Possible relation to proteine, 46. equilibrium renders a compound liable to transAcid, Cyanic. Its formula, 81. formations, 63. In producing the vital phenoAcid, Cyanuric. Its formula, 81. mena, it is modified by other forces, 63. It is Acid, Hippuric. Its composition, 98. Appears not alone the vital force or vitality, but is exin the urine of stall-fed animals, 31. Is de- erted in subordination to that force, 70. stroyed by exercise, 31, 45. Is probably formed Air. Introduced into the stomach during digestion 103 104 INDEX. with tile saliva, 38. Effects of its temperature Of arterial membrane, 95. Of horny tissues, and density, dryness, &c., in respiration, 14, 15. 95. Of the lining membrane of the egg, 95. Albumen. Animal and vegetable albumen identi- Of feathers, 95. Of the'pigmentum nigrum, 95. cal, 22. 23. Their composition, 87, 93. Ve- Of choleic acid, 96. Of taurine, 96. Of chogetable albumen, how obtained, 22. Is a com- loidic acid, 96. Of cholic acid, 98. Of uric pound of proteine, and in organic composition acid, 98. Of alloxan, 98. Of urea, 98. Of identical with fibrine and caseine, 36, 37. Exists hippuric acid, 98. Of allantoine, 98. Of xanin the yolk as well as the white of eggs, 37. thic oxide, 99. Of cystic oxide, 99. Of oxAlso in the serum of the blood, 21. Is the true alic acid, 99. Of oxaluric acid, 99. Of para starting point of all the animal tissues, 37. banic acid, 99. Of roasted flesh, 100. Of Alcohol. Is hurtful to carnivorofis savages, 56. lithofellic acid, 100. Of solanine, 100. Of Its mode of action: checks the change of mat- picrotoxine, 100. Of quinine, 100. Of molter, 72. In cold climates serves as an element phia, 101. Of caffeine, theine, or guaranine, of respiration, 16. 101. Of theobromine, 101. Of asparagine, 101. Aldehyde. Its composition; how related to that Animal Heat. Derived from the combination of of acetic acid, 80, 81. oxygen with the carbon and hydrogen of the Alkalies. Mineral alkalies essential both to' ve- metamorphosed tissues, which proceed ultigetable and animal life, 52. Vegetable alkalies mately from the food, 15. Is highest in those all contain nitrogen, all act on the nervous sys- animals whose respiration is most active, 15. tem, and are all poisonous in a moderate dose, Is the same in man in all climates, 15, 16. Is 56, 57. Theory of their action: they take a kept up by the food in proportion to amount share in the transformation or production of of external cooling, 16. Is not produced either nervous matter, for which they are adapted by by any direct influence of the nerves, or by their composition, 57-59. Action of caustic muscular contractions, 18, 19. Its amount in alkalies on bile, or choleic acid, 44. man, 19. Chemical action the sole source of it, Allantoine. Is found in the urine of the fcetal 20. The formation of fat from starch or sugar calf. How derived from proteine. How re- must produce heat, 34. The elements of the lated to uric acid'and urea, 46. How related bile, by combining with oxygen, serve chiefly Jo choleic acid, 47. Its composition, 98. to produce it, 26. Allen and Pepys. Their calculation of the amount Animal Life. Distinguished from vegetable life of inspired oxygen, 82. by the absorption of oxygen, and the producAlloxan. Formed by the oxidation of uric acid, - tion of carbonic acid, 11. Must not be con45. Converted by oxidation into oxalic acid founded with consciousness, 12. Conditions and urea, oxaluric and parabanic acids, or car- necessary to animal life, 13, 14. Depends on bonic acid and urea; 45.'How related to tau- an equilibrium between waste and supply, 72, rine, 50. Seems to act as a diuretic. Recom- 74, 75. mended for experiment in hepatic diseases, 45. Antiseptics. They act by putting a stop to fer(?note.) mentation, putrefaction, or other forms of metaAlmonds, Bitter. Oil of. Its composition; how morphosis, 54. Their action on wounds and related'to benzoic acid, 81. ulcers, 41. Ammonia.' Combined with uric acid it forms the Arteries. Composition of their tunica media, 95. urine of serpents, birds, &c., 24. Its relation How derived from proteine, 42. to choleic, choloidic, and cholic acids, 44. Is Arterial Blood. Conveys oxygen to every part one of the products which may be formed by of the body, 26, 77. Contains a compound of the oxidation of blood, 45; or of proteine, 48. iron, most probably peroxide, 77. Yields oxygen Its relation to uric acid, urea, and taurine, 49. in passing through the capillaries, 26, 79. ConTo allantoine and taurine, 49. To alloxan and tains carbonic acid dissolved or combined with taurine, 49. To choleic and choloidic acid and soda, 79. taurine, 50. To urea, water, and carbonic Asparagine. Its composition, 101. Its relation to acid, 51. Is found in combination with acids taurine and bile, 56. Theory of its action on in the urine of the carnivora, 52. the bile, 57. Analysis. Of dry blood, 82, 96. Of dried flesh, Assimilation. In animals it is independent of ex96. Of fEeces, 83. Of black bread, 83. Of ternal influences, 11. Depends on the presence potatoes, 83. Of peas, 83. Of beans, 83. Of in the blood of compounds ofd proteine, such as lentils, 83. Of fresh meat, 83. Of moist fibrine, albumen, or caseine, 21. Is more enerbread, 83. Of moist potatoes, 83. Of the getic in the young than in the adult animal, 27. fibrine and albumen of blood, 87, 94. Of ve- Is also more energetic in the herbivora than in getable fibrine and albumen, vegetable caseine the carnivora, 31. and gluten, 88. Of animal caseine, 88. Of Atmosphere. See Air. starch, 88. Of grape or starch sugar, 88. Of Azotized Products. Of vegetable life, 55-57. sugar of milk, 89. Of gum, 89. Of oats, 89. Of the metamorphosis of tissues. Necessary Of hay,'89. Of fat, 90. Of cane-sugar, 90. for' the formation of bile in the herbivora, 51. Of cholesterine, 90. Of wax, 92. Of cyanic In man, 53. May be replaced by azotized veacid, cyanuric acid, and cyamelide, 92. Of getable compounds, 54..Theory of this, 56aldehyde, metaldehyde, and elaldehyde, 92. Of 57. Of the transformation of the bile, or of proteine, 93. Of albumen from the yolk and choleic acid; how related to the constituents of white of egg, 93. Of lactic acid, 93. Of gas urine, 50. from the stomach of cows after eating to ex- 1B. cess, 93. Of gas from stomach and intestines Beans. Comp osition of, 83. of executed criminals, 93. Of gelatinous tis- Beer. Forms part of the diet of soldiers in Ger sues, 94. Of tissues containing chondrine, 95. many, 83, 85. INDEX. 105 Bees. Their power of forming wax from honey, r Bread. Analysis of, 83. 90-92. Brund. His analysis of sugar of milk, 89. Benzoic Acid. See Acid, Benzoic. Buckwheat. Analysis of starch from, 88. Berthollet. His analysis of oxalic acid, 99. Burdach. His statement of the amount of bile Berzelius. His analysis of potato starch, 88; of secreted by animals, 27. sugar of milk, 89; of gum, 89; of cane sugar, 90. Butter. Forms a part of the food of soldiers in Bezoar stones. See Acid, Lithofellic. Germany, 83, 84. Blanchet. His analysis of solanine, 100. Buzzard. Its excrements consist of urate of amBile. In the carnivora is a product of the meta- monia, 24. morphosis of the tissues, along with urate of C. ammonia, 44. May be represented by choleate Caffeine. Identical with theine, 56. Its relation of soda, with which, however, it is not identi- to taurine and bile, 56. Theory of its mode of cal, 97. Products of its transformation, 44, action, 57. Its composition, 101. 97. Remarks on these, 96-97. Origin of Cane Sugar. Its composition, 90. bile, 26, 46. Starch, &c., contribute to its Carbon. Is accumulated in the bile, 21. Is given formation in the herbivora, 47, 48, 51, 53. off as carbonic acid, 14. Excess of carbon Soda essential to it, 49, 52. Relation of bile causes hepatic diseases, 17. By combining to urine, 50.'To starch, 51. To fibrine, 44. with oxygen, it yields the greater part of the To caffeine, &c., asparagine, and theobromine, animal heat. See Animal Heat, Bile, and Acid, 57. For the acid substances derived fiom bile, Carbpnic. Amount of carbon oxidized daily in choleic, choloidic, and cholic acids, see Acid, the body of a man, 14. Calculations on which Choleic, &c. Yields taurine, 44. Contains this statement is founded, 82-85. Amount cholesterine, 32, 97. Also stearic and mar- consumed by the horse and cow, 14. Different garic acids, 97. Its function: to support proportions of carbon in different kinds of food, respiration and produce animal heat by pre- 15. Carbon of flesh compared with that of senting carbon and hydrogen in a very soluble starch, showing the advantage of a mixed diet, form to the oxygen of the arterial blood, 26, 27. 30. Calculation on which this statement is Amount secreted by the dog, the horse, and founded, 89. Amount of carbon in dry blood man, 27. It returns entirely into the circula- calculated, 82. Amount in the food of prisoners tion, and disappears completely, 26, 27. calculated, 87. Blood. The fluid from which every part of the Carbonic Acid. See Acid, Carbonic. body is formed, 13. Its chief constituents, 21. Carbonates. They occur in the blood, 21. How formed from vegetable food, 22. Can Calculus, Mulberry. Derived from the imperfect only be formed from compounds of-proteine, 23. oxidation of uric acid, 45. Uric acid calculus Is therefore entirely derived from vegetable pro- is formed in consequence of deficiency of inducts in the herbivora, and indirectly also by spired oxygen, or excess of carbon in the food, the carnivora, which feed on the flesh of the 45. See Acid, Uric. Bezoar stones composed former, 23. Its composition identical with that of lithofellic acid, 49. of flesh, 44. Analysis of both, 96. The se- Carnivora. Their nutrition the most simple, 22, cretions contain all the elements of the blood, It is ultimately derived from vegetables, 23. 43. Its relation to bile and urine, 44. Pro- Their young, like graminivora, require nonducts of the oxidation of blood, 45. Excess of azotized compounds in their food, 23. Their azotized food produces fulness of blood and dis- bile is formed from the metamorphosis of their ease, 47. Soda is present in the blood, 52. tissues, 25, 26. The process of assimilation in Important properties of the blood, 54-55..adult and young carnivora compared, 27. Their Venous blood contains iron, probably as pro- urine, 30. The assimilative process in adult toxide; arterial blood, probably as peroxide, 79. carnivora less energetic than in graminivora, 31. Theory of the poisonous action of sulphuretted They are destitute of fat, 31. They swallow hydrogen and prussic acid: they decompose less air with their food than graminivora, 40. the compound of iron in the blood, 79. The Concretions of uric acid are never found in blood, in analogous morbid states, ought to be them, 47. Both soda and ammonia found in chemically examined, 80. their urine, 52. Blood-letting.. Theory of its mode of action, 78. Caseine. One of the azotized nutritious products It may produce opposite effects in different of vegetable life, 22. Abundant in leguminous cases, 77. plants, 22. Identical in organic composition Bceckmann. His analysis of black bread, 83; of with fibrine and albumen, 22, 23. Animal potatoes, 83; of dry beef, 96; of dry blood, 96; caseine found in milk and cheese; identical of roasted flesh, 100. with vegetable caseine, 23. Furnishes blood Bones. Phosphoric acid of the food retained to to the young animal, 24. Is one of the piastic: assist in forming them, 31. Gelatine of bones elements of nutrition, 35.'Yields proteine, 37. digested by dogs, 35. See, further, Gelatine. Its relation to proteine, 42. It contains sulCause of brittleness in bones, 36. phur, 42. Potash essential to its production, 52. Boussingault. His analysis of potatoes, 83. His Contains more of the earth of bones than blood comparison of the food and excretions in the does, 24. Its analysis, 88. horse and cow, Table, 86. His analysis of Cerebric Acid. See Acid, Cerebric. gluten, 87; of vegetable albumen, 87; of ve- Change of Matter. See Metamorphosis of Tissuea getable caseine, 88; of oats, 89; of hay, 89. Chemical Attraction. See Affinity, Braconnot. On the presence of lactic acid in C(hevreul. His researches on fat, 32. His ana gastric juice, 38; of iron in the gastric juice of lysis of fat, 90; of cholesterine, 90. the dog, 38. Chloride of Sodium. See Common Salt. Brain. See Acid, Cerebric, and Nervous Matter. Choleic Acid. See Acid, Choleic. 14 106 INDEX. Cholesterine. See Bile. Disease. Theory of, 74 et seq. Cause of death Cholic Acid. See Acid, Cholic. in chronic disease, 17. Disease of liver caused Choloidic Acid. See Acid, Choloidic. by excess of carbon or deficiency of oxygen, 16. Chondrine. Its relation to proteine, 42. Ana- Prevails in hot weather, 17. lysis of tissues containing it, 95. Dog. Amount of bile secreted by, 27. Digests Chronic Diseases. The action of inspired oxy- the gelatine of bones, 35. His excrements congen is the cause of death in them, 17, 18. tain only bone earth, 36. Concretion of urate Chyle. When it has reached the thoracic duct, of ammonia said to have been found by Lasit is alkaline, and contains albumen coagulable saigne in a dog, doubtful, 47 (note.) by heat, 47. Dumas. His analysis of choleic acid, 96; of Chyme. It is formed independently of the vital choloidic acid, 96; of taurine, ib.; of cholic force, by a chemical transformation, 37. The acid, 97; of hippuric acid, 98. substance which causes this transformation is E. derived from the living membrane of the sto- Eggs. Albumen of the white and of the yolk mach, 37. Chyme is acid, 47. identical, 37 Analysis of both, 93; of lining Clothing. Warm clothing is a substitute for food membrane, 95. The fat of the yolk may conto a certain extent, 16. Want of clothing ac- tribute to the formation of nervous matter, 37. celerates the rate of cooling, and the respira- This fat contains iron, 37. tions, and thus increases the appetite, 16. Elaldehyde. See Aldehyde. Cold. Increases the appetite by accelerating the Elements. Of nutrition, 35. Of respiration, 35. respiration, 16. Is most judiciously employed Empyreumatics. They check transformations, 54 as a remedy in cerebral inflammation, 76. Their action on ulcers, 41. Concretions. See Calculus, and Acid, Uric; also Equilibrium. Between waste and supply of matAcid, Lithofellic. ter is the abstract state of health, 74, 78. Constituents, Azotized. Of blood: see Fibrine Transformations occur in compounds in which and Albumen. Of vegetables: See Fibrine, the chemical forces are in unstable equiliVegetable; Albumen, Vegetable; Caseine, Ve- brium, 37. getable; Alkalies, Vegetable; and Caffeine. Ettling. His analysis of wax, 92. Ettling and Of bile: see Acid, Choleic, Cholic, and Cho- Will, their analysis of lithofellic acid, 100. loidic. Of urine: see Acid, Uric; Urea, and Excrements. Contain little or no bile in man Allantoine. and in the herbivora, none at all in the dog and Cooling. See Cold and Clothing. other carnivora, 27. Those of the dog are Couerbe. His analysis of cholesterine, 90. phosphate of lime, 35. Those of serpents are Cow. Amount of carbon expired by the, 14. urate of ammonia, 24. Those of birds also Comparison of the food with the excretions of contain that salt, 24. Those of the horse and the cow, 86. cow compared with their food, 86. Crum. His analysis of cane sugar, 90. Excretions. Contain, with the secretions, the Cultivation. Is the economy of force, 30. elements of the blood or of the tissues, 43, 44. Cyamelide. Its formula, 81. - Those of the horse and cow compared with Cyanic Acid. See Acid, Cyanic. their food, 86. Bile is not an excretion, 26. Cyanide of Iron. Its remarkable properties, 78. F. Cyanuric Acid. See Acid, Cyanuric. Freces. Analysis of, 83. D. Fat. Theory of its production from starch, when Davy. Oxygen consum-ed by an adult man, 82. oxygen is deficient, 32 et seq.; from other subDeath. Cause of, in chronic diseases, 17, 18. stances, 32. The formation of fat supplies a Caused in old people by a slight depression of new source of oxygen, 33; and produces heat, temperature, 75. Definition of it, 74. 33 et seq. Maximum of fat, how obtained, 34. Demargay. His analysis of choleic acid, choloidic Carnivora have no fat, 31. Fat in stall-fed acid, and taurine, 96. Remarks on his Re- animals, 33. Occurs in some diseases in the searches on Bile, 97. blood, 35. Fat in the women of the East, 36. Denis. His experiments on the conversion of Composition compared with that of sugar, 32. fibrine into albumen, 21. Analysis of fat, 90. Disappears in starvation, Despretz. His calculation of the heat developed 17. Is an element of respiration, 35. in the combustion of carbon, 19. Fattening of Animals. See Fat. Diabetes Mellitus. The sugar found in the urine Featherwhite Wine. Its poisonous action, 39. in this disease is grape sugar, and is derived Febrile Paroxyism. Definition of, 75. from the starch of the food, 35. Fehling. His analysis of metaldehyde and elalDiastase. Analogy between its solvent action on dehyde, 92. starch, and that of the gastric juice on coagu- Fermentation. May be produced by any azotized lated albumen, 38. matter in a state of decomposition, 40. Is arDiffusion of Gases. Explains the fact that nitro- rested by empyreumatics, 40., Is analogous to gen is given out through the skin of animals, digestion, 40. 40; and the poisonous action of feather-white Fever. Theory and definition of, 75. wine, 39. Fibre. Muscular. See Flesh. Digestion. Is effected without the aid of the vital Fibrine. Is an element of nutrition, 35. Animal force, by a metamorphosis derived from the and vegetable fibrine are identical, 22. Is a transformation of a substance proceeding from compound of proteine, 36. Its relation to prow the lining membrane of the stomach, 37. The teine, 42. Convertible into albumen, 21. Is oxygen introduced with the saliva assists in derived from albumen during incubation, 37. the process, 38, Lactic acid has no share in Its analysis, 87, 94. Vegetable ibrine, how it, 38. obtained, 22. INDEX. 107 Fishes. Yield phosphuretted hydrogen, 59 (note.) Globules of the blood are the carriers of oxygen Flesh. Consists chiefly of fibrine, but, from the to all parts of the body, 54-55. They conmixture of fat and membrane, has the same tain iron, 77 et seq. formula as blood, 44. Analysis of flesh, 96, 100. Gluten. Contains vegetable fibrine, 22. AnaAmount of carbon in flesh compared with that lysis of it, 87. of starch, 30, 86. Gmelin. On the sugar of bile, 47. Food. Must contain both elements of nutrition Goose. How fattened to the utmost, 34. and elements of respiration, 35. Nutritious Graminivora. See Herbivora. food, strictly speaking, is that alone which is Grape-sugar. An element of respiration, 35. Is capable of forming blood, 21. Whether derived identical with starch sugar and diabetic sugar, from animals or from vegetables, nutritious food 29. Its composition, 29. Its analysis, 88. contains proteine, 22, 37 et seq. Changes Growth, or increase of mass, greater in graminiwhich the food undergoes in the organism of vora than in carnivore, 31. Depends on the the carnivora, 24 et seq. The food of the herbi- blood, 21; and on compounds of proteine, 37. vora always contains starch, sugar, &c., 28. See Nutrition. Food, how dissolved, 38 et seq. Azotized food Gum. An element of respiration, 36. Its comrnhas no direct influence on the formation of position, 35. Is related to sugar of milk, 35. uric acid calculus, 45. Effects of superabundant Its analysis, 89. azotized food. 47. iNon-azotised food contri- Gundlach. His researches on the formation of butes to the formation of bile, and thus to of wax from honey of the bee, 91. respiration, 47 e seq. Salt must be added to H. the food of herbivora, in order to yield soda for Hair. Analysis of, 95. Its relation to proteine, the bile, 52. Caffeine, &c., serve as food for 42. Analysis of proteine from hair, 93. the liver, 59. The vegetable alkalies may Le Hay. Analysis of, 89. viewed as food for the organs which form the Hepatic Diseases. Cause of, 16. nervous matter, 59. Amount of food con- Herbivora. Their blood derived from compounds sumed by soldiers in Germany, 83. Its ana- of proteine in their food, 23. But they require lysis, 82. Food of the horse and cow com- also for their support non-azotized substances, pared with their excretions, 86. 28. These last assist in the formation of their Formula. Explanation of their use, 81. How bile, 47 et seq. They retain the phosphoric reduced to 100 parts, 81. Formula of albu- acid of their food to form bone and nervous men, fibrine, caseine, and animal tissues, 42. matter, 31. Their urine contains very little Formula of proteine, 41; of blood and flesh, 44; phosphoric acid, 31. The energy of vegetative of fat, 32; of cholesterine, 32; of aldehyde, life in them is very great, 31. They become acetic acid, oil of bitter almonds, and benzoic fat when stall-fed, 31. acid, 81; of cyamelide, cyanic acid, and cyan- Hess. His analysis of wax, 93. uric acid, 81; of choleic acid, 44; of choloidic Hybernating Animals. Their fat disappears duracid and cholic acid, 44; of gelatine, 46; of ing the winter sleep, 17. They secrete bile hippuric acid, 48; of lithofellic acid, 49; of and urine during the same period, 26. taurine, 49; of alloxan, 49. See Analysis. Hippuric Acid. See Acid, Hippuric. Francis. His analysis of picrotoxine, 100. Horn. Analysis of, 95. Contains proteine; its Fremy, Lameyran and Frdmy. Their analysis of relation to proteine, 42. Analysis of proteine gas from the abdomen of cows after excess in fresh from horn, 93. food, 93. His researches on the brain, 21, 57. Horse. Amount of carbon expired by, 14. ComnFrequency of the pulse and respiration in different parison of his food with his excretions, 86. animals, 15, 87. Force exerted by a horse in mechanical motion Fruits. Contain very little carbon, and hence are compared to that exerted by a whale, 70. adapted for food in hot climates, 15. Hydrocyanic Acid. See Acid, Hydrocyanic. G. Hydrogen. By combining with oxygen contri Gas. Analysis of gas from abdomen of cows butes to produce the animal heat, 17. after excess in fresh food, 39, 93. Analysis of I. gas from the stomach and intestines of executed Ice. Is judiciously employed as a remedy in criminals, 39, 93. cerebral inflammation, 76. Gastric Juice. Contains no solvent but a sub- Inorganic constituents of albumen, fibrine, and stance in a state of metamorphosis, by the pre- caseine, 21, 41, 42. sence of which the food is dissolved, 37. Con- Jobst. His analysis of theine, 101. tains free acid, 37.- Contains no lactic acid, 38. Jones, Dr. Bence. His analysis of vegetable In the dog has been found to contain iron, 38. fibrine, 86; of vegetable albumen, 87; of veSee Digestion, Chyme, Food. getable caseine, 87; of gluten, 87; of the albuGay-Lussac and Thdnard. Their analysis of men of yolk of egg, 93, 94; of the albumen of starch, 88; of sugar of milk, and of gunm, 89; of brain, 94. cane sugar, 90; of wax, 92; of oxalic acid, 99. Iron. Is an essential constituent of the globules Gelatine. Is derived from proteine, but is no of the blood, 77 et seq. Is found in the fat of longer a compound of proteine, and cannot yolk of egg, 37. Also in the gastric juice of form blood, 42 et seq. May serve as food for the dog, 38. Singular properties Qf its colthe gelatinous tissues, and thus spare the sto- pounds, 78. mach of convalescents, 35, 43. In starvation Isomeric Bodies, 36, 81. the gelatinous tissues remain intact, 35. Its K. relation to proteine, 42. Its formula, 46. Its Keller. His researches on the conversion of analysis, 94, 100. benzoic acid into hippuric acid in the human G(oebel. His analysis of gum, 89. body, 101. 108 INDEX. Kidneys. They separate from the arterial blood Muscle. See Flesh. the nitrogenized compounds destined for excre- Muscular Fibre. Its transformation depends on tion, 49. the amount of force expended in producing L. motion, 66. Lactic Acid. See Acid, Lactic. N. Lavoisier. His calculation of the amount of in- Nerves. Are the conductors of the vital force, spired oxygen, 14, 81.. and of mechanical effects, 66. Effects of the Lehmann. On the presence of lactic acid in disturbance of their conduting power, 68. They gastric juice, 38. are not the source of animal heat, 18. Liebig. His analysis of sugar of milk, 89; of Nervous Life. Distinguished from vegetative, 20. cane sugar, 90; of aldehyde, 92; of uric acid, Nervous Matter. Contains albumen, and fatty 97; of hippuric acid, 98; of quinine, 100; of matter of a peculiar kind, 2 1. Vegetables canmorphia, 101; of asparagine, 101. His calcu- not produce it, 23. The fat of yolk of egg lation of the carbon daily expired as carbonic probably contributes to its formation, 37. The a6id, 14, 82. Table, 84. His remarks on phosphoric acid and phosphates, formed in the Demarcay's researches on bile, 96, 97. metamorphosis of the tissues of the herbivora, Liebig and Pfaff Their analysis of caffeine, 101. are retained to assist in the formation of nervous Liebig and W5/ohler. Their analysis of alloxan, matter, 31. The vegetable alkalies affect the 98; of urea, 98; of allantoine, 98; of xanthic nervous system, 57. Composition of cerebric oxide, 99; of oxalulric acid, 99; of parabanic acid. Theory of the action of the vegetable acid, 99. alkalies, 58. Lentils. Contain vegetable caseine, 22. Ana- Nitrogen. Essential to all organized structures, lysis of, 82, 83. Form part of the diet of sol- 21. Substances in the body which are destitute diers in Germany, 83. Table, 85. of it not organized, 21. Abounds in nutritious Light. Its influence on vegetable life analogous vegetables, 22, Nutritious forms in which it to that of heat on animal life, 69. occurs, 22 et seq. Occurs in all vegetable poiLime. Phosphate of. See Bones. sons, 56; also in a few substances which are Liver. It separates from the venous blood the neither nutritious nor poisonous, but have a carbonized constituents destined for respiration, peculiar effect on the system, such as caffeine, 25. Diseases of the liver, how produced, 16. 56 et seq. Accumulation of fat in the liver of the goose, 35. Nitrogenized. See Azotized. M. Non-Azotized. Constituents of food. See Starch. Maize. Analysis of starch from, 88. Nutrition. Depends on the blood, 21. On AlbuMarchand. On the amount of urea in the urine men, fibrine, or caseine, 21 et seq. Elements of the dog when fed on sugar, 26. His ana- of nutrition, 35. Compounds of proteine alone lysis of cholesterine, 90. are nutritious, 37. Occurs when the vital force Marcet. His analysis of gluten, 87. is more powerful than the opposing chemical Martius. His analysis of guaranine, 101 forces, 60. Theory of it, 63. Is almost unliMechanical Effects. See Motion. mited in plants from the absence of nerves, 64. Medicine. Definition of the objects of, 75 et seq. Depends on the momentum of force in each Action of medicinal agents, 54 et seq. part, 68. Depends also on heat, 72. Menzies. His calculation of the amount of in- 0. spired oxygen, 14, 81. Oats. Amount required to keep a horse in good Metaldehyde. See Aldehyde. condition, 29. Analysis of, 89. Metamorphosis of Tissues, 36 et seq. In other Oil of Bitter Almonds. Its composition. How parts of the volume, passim. related to benzoic acid, 81. Milk. Is the only natural product perfectly fitted Old Age. Characteristics of, 73 et seq. to sustain life, 23. Contains caseine, 23. Fat Oppermann. His analysis of wax, 92. (butter), 23. Sugar of milk, 23. Earth of Organs. The food of animals always consist of bones, 23. And potash, 52. parts of organs, 11. All organs in the body Morphia. Contains less nitrogen than quinine, contain nitrogen, 21. There must exist organs 56. Its analysis, 101. for the production of nervous matter, 59; and Mitscherlich. His analysis of uric acid, 96; of the vegetable alkalies may be viewed as food hippuric acid, 96. for these organs, 59. Momentum. Of force, 61. Of motion, 61. Organized Tissues. All contain nitrogen, 21. Motion. Phenomena of motion in the animal All such as are destined for effecting the change body, 60 et seq. Different sources of motion, of matter are full of small vessels, 67. Their 60. Momentum of motion, 61. Motion pro- composition, 42. The gelatinous and cellular pagated by nerves, 60. Voluntary and invo- tissues, and the uterus, not being destined for luntary motions accompanied by a change of that purpose, are differently constructed, 67. form and structure in living parts, 66. Motion Waste of organized tissues rapid in carnivora, derived from change of matter, 66 et seq. The 30. cause of motion in the animal body is a peculiar Origin. Of animal heat, 15, 18. Of fat, 31 et force, 69. The sum of the effects of motion in seq. Of the nitrogen exhaled from the lungs, the body proportional to the amount of nitrogen 39 et seq. Of gelatine, 42 et seq., 48. Of in the urine, 72. uric acid and urea, 44 et seq. Of bile, 44, 47, Mulberry Calculus. See Calculus. 48 et seq. Of hippuric acid, 48, 101. Of the.Mulder. Discovered proteine, 36. His analysis chief secretions and excretions, 49. Of the of fibrine of blood, 87. Of animal caseine, 88. soda of the bile, 52 et seq. Of the nitrogen in Ofproteine, 88. Of fibrine, 94. Of gelatine, bile, 53. Of nervous matter, 57 et seq. 94. Of chondrine, 95. Ortigosa. His analysis of starch, 88. INDEX. 109 Oxalic Acid. A product, along with urea, of the Their capacity of growth almost unlimited, 64, partial oxidation of uric acid, occurring in Cause of death in plants, 64. the form of mulberry calculus, 45. Its analysis, Playfair, Dr. L. His formula for blood, 38. His 99. analysis of faeces, of peas, of lentils, of beans, Oxygen. Amount consumed by man daily, 14, 82; of flesh and of blood, 96; of roasted flesh, 80. Amount consumed daily in oxidizing car- 100. bon by the horse and cow, 14. The absorption Poisons, Vegetable. Always contain nitrogen, of oxygen characterizes animal life, 11. The 55 el seq. Different kinds of poisons, 54. action of oxygen is the cause of death in star- Theory of the action of prussic acid and sulvation and in chronic diseases, 17-18. The phuretted hydrogen, 80. amount of oxygen inspired varies with the tem- Polymeric Bodies, 36. perature, dryness, and density of the air, 15. Potash. Essential to the production of caseine ol Is carried by arterial blood to all parts of the milk, 52. body, 54. Fat differs from sugar and starch Potatoes. Amount of carbon in, 83. They form only in the amount of oxygen, 32. It also part of the diet of soldiers in Germany, 83. contains less oxygen than albumen, fibrine, &c., Analysis of, 83; of starch from, 83; of sola32. The formation of fat depends on a defi- nine from the buds of germinating potatoes, 100. ciency of oxygen, 33 et seq.; and helps to sup- Prevost and Dumas. On the frequency of the ply this deficiency, 33. Oxygen essential to pulse and respirations, 86. digestion, 38. Relation of oxygen to some of Products. Of the metamorphosis of tissues found the tissues formed from proteine, 42. Oxygen in the bile and urine, 43. Of the action of and water, added to blood or to flesh, yield the muriatic acid on bile, 44. Of the action of elements of bile and of urine, 44. Action of potash on bile, 44. Of the action of water and oxygen on uric acid, 44, 45: on hippuric acid, oxygen on blood or fibre, 44. Of the oxidation 31, 45; on blood, 45; on proteine, with'uric of uric acid, 45. Of the oxidation of blood, 45 acid, 48; on proteine and starch, with water, 49; Of the action of water on proteine, 46. Of the on choleic acid, 49; on proteine, with water, action of urea on lactic and benzoic acids, 48 49. By depriving starch of oxygen and water, Of oxygen and uric acid on proteine, 48. Of choloidic acid may be formed, 51. Oxygen oxygen on starch and hippuric acid, 48. Of is essential to the change of matter. 55. Its oxygen and water on proteine and starch, 49. action on the azotized constituents of plants Of oxygen and water on proteine when soda is when separated, 64. Its action on the muscular absent, 49. Of the separation of oxygen from fibre essential to the production of force, 66, 67. starch, 50. Of the action of water on urea, 51. Oxygen is absorbed by hybernating animals, 71. Of the action of water and oxygen on caffeine Is the cause of the waste of matter, 72; and or theine, asparagine, and theobromine, 56. of animal heat, 72, 74. Blood-letting acts by Proteine. Discovered by Mulder, 36. Its comrn. diminishing the amount of oxygen which acts position, 36. Produced alone by vegetables, 37. on the body, 75. Its absorption is the cause of Is the source of all the organic azotized constithe change of colour from venous to arterial tuents of the body, 37. Its formula, 41. Its blood, 77. The globules probably contain oxide relation to fibrine, albumen, caseine, and all the of iron, protoxide in venous blood, peroxide in animal tissues, 42. Gelatine no longer yields arterial, 78 et seq. All parts of the arterial it, although formed from it, 43. Its relation to blood contain oxygen, 55, 77, 79. bile and urine, 44. Its relation to allantoine P. and choloidic acid, 46; to gelatine, 46; to hip. Pears. Analysis of starch from unripe, 88. puric acid, 48; to the chief secretions and ex. Peas. Form part of the diet of soldiers in Ger- cretions, 48, 49; to fat, 49 Analysis of pro. many, 83, 85. Abound in vegetable caseine, teine from the crystalline lens, from albumen, 22. Analysis of peas, 83; of starch from from fibrine, from hair, from horn, from vegeta. peas, 88. ble albumen and fibrine, from cheese, 92. Pepys and Allen. Their calculation'of the Prout. His analysis of starch, 88; of grape su. amount of inspired oxygen, 82. gar from honey, 88; of sugar of milk, 88; of Peroxide of Iron. Probably exists in arterial cane sugar, 89; of urea, 90. His discovery of blood, 78 et seq. free muriatic acid in the gastric juice, 38. On Pfluger. His analysis of the gas obtained by the effect of fat food on the urine, 45. puncture from the abdomen of cattle after ex- Prussic Acid. See Acid, Hydrocyanic. cess in green food, 93. Pulmonary Diseases. Arise from excess of oxy. Phenomena of motion in the animal body, 60 gen, 16. Prevail in winter, 17. et seq. Pulse. Its frequency in dillfferent animals, 86. Phosphates. See Bones. Putrefaction. Is a process of transformation, 37. Phosphoric Acid. See Acid, Phosphor:c, Membranes very liable to it, 38. Effects of the Phosphorus. Exists in albumen and hbrine, 21, putrefaction of green food in the stomach of 23, 42. It is not known in what form, 41 et animals, 39. Is analogous to digestion, 40. seq. Is an essential constituent of nervous mat- Putrefying animal matters cause the fermenta. ter, 57, 59. tion of sugar, 40. Is checked by empyreuma. Phosphuretted Hydrogen. Occurs among the pro- tics, 41, 54. ducts of the putrefaction of fishes, 59. Q. Picrotoxine. Contains nitrogen, 56 (note.) Its Quinine. Contains nitrogen, 56. Its analysis, analysis, 100. 100. Plants. Distinguished from animals by fixing R. carbon and giving out oxygen, 11, 64; by the Regnault. His analysis of morphia, 101. want of nerves and of l;comotive powers, 11. Reproduction of Tissues. See Nutrition. R 110 INDEX. Reproduction of the Species, 20. 50, to alloxan, 50, to choloidic and choleic acids, Rhenish Wines. Contain so much tartar, that and ammonia, 51, to caffeine or theine, 56, to their use prevents the formation of uric acid asparagine, 56, to theobromine, 57. calculus, 49. Temperature. Its effects on the amount of in Respiration. Theory of, 77 et seq. Its connexion spired oxygen, 15, and on the appetite, 15 et with the food and with animal heat, 14 et seq. seq. A slight depression of temperature causes S. death in aged people, 75. Temperature of the Salt, Common. Essential to the formation of blood in different animals, 87. Temperature bile in the herbivora, and to that of gastric juice, of the body constantly kept up by internal 52 et seq. causes, 15, 16. Saussure, De. His analysis of grape sugar and Tendons. Analysis of, 94. of starch sugar, 88, of wax, 92. Thaulow. His analysis of cystic oxide, 99. Scherer, Dr. Jos. His analysis of albumen from Theine. Is identical with caffeine, 56. And serum of blood, 87, of fibrine of blood, 87, with guaranine, 57. Theory of its action, 57 of vegetable fibrine, 87, of vegetable caseine, 88, et seq. Its relation to bile, 56. Its analysis, of animal caseine, 88, of proteine from differ- 101. ent sources, 92, of albumen from white of egg, Theobromine. Analogous to theine, 56. Theory 92, of albumen from different sources, 94, of of its action, 57 et seq. Its relation to bile, 56, fibrine, 94, of gelatine from different sources, 57. Its analysis, 101. 94, of tissues containing chondrine, 95, of the Theory. Of animal heat, 15 et seq. Of digestunica media of arteries, 95, of horny tissues, tion, 37 et seq. Of respiration, 77 et seq. Of 95, of the lining membrane of the egg, 95, of the motions in the ahimal organism, 60 et seq. feathers, 95, of the pigmentum nigrum oculi, Of disease, 74 et seq. Of the action of caffeine, 95. Results of his researches, 42. &c., 57 et seq. Of the action of the vegetable Secretions. See Bile and Urine. alkalies, 57 et seq. Of health, 74, 75. Seguin. His calculation of the amount of inspired Tiedemann and Gmelin. Their attempt to supoxygen, 80. port a goose upon albumen alone, unsuccessful, Serpents. Their excrements consist of urate of 37. ammonia, 24. The process of digestion in Tissues, Metamorphosis of: see Metamorphosis. them, 24. Analysis of the animal tissues, 94, 95. FormuSleep, Theory of, 68. Amount of sleep necessary le of, 42. for the adult, the infant, and the old man, 73 et Tobacco. Arrests or retards the change of matter, seq. Induced by alcohol or wine, 71. 56. Soda. Essential to blood and bile, and derived Transformation. See Metamorphosis. from common salt, 76 et seq. Turnips. Juice of, contains vegetable fibrine and Sodium, Chloride of. See Salt. albumen, 22. Solanine. Contains nitrogen, 56. Its analysis, 100. U. Starch. Exists in the food of the herbivora, 28. Urea. Derived from uric acid, 45. Also from Is convertible into sugar, 28, 29. Its relation the oxidation of blood, 45; from allantoine, 46. to gum and sugar, 29. Its function in food, 29 Its relation to choleic acid, 48; to hippuric et seq. Amount of carbon in starch compared acid, 48; to proteine, 48; to proteine and with that in flesh, 30. Its composition com- starch, 49; to proteine and fat, 49; to taurine, pared with that of fat, 32, 33. Is the source 50; to carbonate of ammonia, 51; to theobroof diabetic sugar, 35. Is an element of respi mine, 56. Its analysis, 98. Occurs in the ration, 35. Dissolved by diastase, 38. Its re- urine of those who have taken benzoic acid lation to choleic acid, 48. Its relation to the along with hippuric acid, 102. principal secretions and excretions, 49, to cho- Urinary Calculi. See Calculus, loidic acid, 51, to bile, 51, 52, 53. Its analysis Uric Acid. See Acid, Uric. from fifteen different plants, 88. V. Starvation. Process of, 17. Cause of death in, 17. Varrentrapp and Will. Their analysis of veStrecker. His analysis of starch from twelve dif- getable albumen, 87. Of sulphate of potash ferent plants, 88. and caseine, 88. Sugar. Analysis of grape-sugar, 88, of sugar of Vegetables. Alone produce compounds of promilk, 89, of cane sugar, 90. Is an element of teine, 37. Azotized constituents of, nutritious, respiration, 35. 22: medical or poisonous, 55. Analysis of Sulphur. Exists in albumen, and cascine, 21, 42. those vegetables which are used for food, 82 Sulphuretted Hydrogen. Theory of its poison- et seq. ous action, 80. Vegetable Life. Distinguished from nervous life, Sulphuric Acid. See Acid, Sulphuric. 20. Predominates in the early stages of life, 8upply of matter. See Nutrition. 20. Also in the female, 20. Supply and Waste. Equilibrium between them Venous Blood. See Blood. constitutes the abstract state of health, 74, 75. Vital force, or vitality. Definition of, 11 et seq. Effects of its disturbance, 75 et seq. Means Theory of, 60 et seq. for restoring the equilibrium, 73, 75 et seq. Vogel. His analysis of gas from the abdomen of T. cattle after-excess in green food, 93. Tables of the food consumed by soldiers of Ger- W. many, 83. Of the food and excretions of the Water. Is one of the two constituents of the horse and cow, 86. body which contain no nitrogen, 21. Its use Taurine. How produced from bile, 44. Its re- as a solvent, 21. Contributes to the greater lation to choleic acid, 44. Its relation to uric part of the transformations in the body, 44acid and urea, and to allantoine, 49, to uric acid 57. INDEX. 111 Wax. On its production from honey by the bee, Wine. The wines of the south promote the 90-92. Its analysis, 92. formation of calculus, 45. But not Rhenish Wheat. Contains vegetable fibrine, 22. Ana- wines, 45. Theory of its action, 72. lysis of fibrine, albumen, and gluten, from Woskresensky. His analysis of theobromine, 101. wheat, 87. Y. Will and Ettling. Their analysis of lithofellic Yams. Analysis of starch from, 88. acid 100,