398 



THE FARMERS' REGISTER. 



the air into carbonic acid and water. This portion 

 ol the report contained an int^enions and import- 

 ant view ot the u?e ol bile in the animal economy, 

 the truth of which quaniimtive physioloiry dare 

 not deny. When exercise is denied to gramini- 

 vorous and omnivorous animals, this is tanta- 

 mount to a deficient supply ol oxytrpn. The car- 

 bon ol the food not meeimtr wiih sul!ii-.ient oxyizen 

 to consume it, passes into the compounds coinain- 

 inf^ a large excess ol carbon, and deficiency ol' 

 oxygen ; or, in oiher words, I'at is produced. 

 Liebig IS led to the startling conclusion, that Cm is 

 altogeiher an abnormal and unnatural production, 

 arising from the adaptation ol nature to circum- 

 stances, and not ot" circumstances to nature — alto- 

 gether arising from a disproportion of carbon in 

 the Ibod to that of the oxygen respired by the 

 lunge, or absorbed by the skin. Wild animals in 

 a stale of nature do not contain fat. The B»"douin 

 or Arab of the desert, who shows with pride his 

 lean, muscular, sinewy limbs, is altogeiher free 

 from fat. And the prolessor points out the dis- 

 eases arising from this cause, and furnishes some 

 valuable hints to iherapeutics. From all that has 

 transpired, we may sum up the niitritiou-^ elements 

 ol Ibod as follow. The ingredients adapted lor 

 the formation of the blood, and which ihe profes- 

 sor calls the plastic elements ol nutrition, are as 

 follow : — vegetable fibrine, vegetable albumen, 

 vegetable caseine, animal Hesh, animal blood. 

 The other ingredients of lood, being fitted to re- 

 tain the temperature of the body, he calls the 

 elements of respiration. They are — lat, starch, 

 gum, cane-sugar, grape-sugar, sugar of milk, 

 pecline, ba-sorine, beer, wine, spirits. These are 

 Prolessor Liebig's general principles of nutrition. 

 The second part of the work consists of details, in 

 which he examines the chemical processes en- 

 gaged in the production of bile, ol urea, uric acid 

 and its compounds, as well as of cerebral and 

 nervous subsiance. The conclusions to which he 

 has arrived on these subjects are of so great and 

 startling interest, that Dr. Piayfidir said, he dare 

 not venture to make an abstract of them, without 

 entering into the calculations with virhich they 

 were accompanied. In the professor's explana- 

 tory remarks on digestion, he ascribes a singular 

 (unction to saliva. This fluid possesses the re- 

 markable property of enclosing air in the shape 

 of froth, in a far higher degree even than soap- 

 suds. This air, by means of the saliva, accom- 

 panies the food inio the stomach, and there its 

 oxygen enters into combination with the consti- 

 tuents of the food, whilst its nitrogen is again 

 given out through the lungs or skin. The longer 

 digestion continues, the greater is the quantity ol 

 saliva, and consequently of air, which enters the 

 stomach. Rumination, in certain graminivorous 

 animals, has plainly ibr one object a renewed and 

 repeated introduction of oxycen. The prolessor 

 further touches upon the use ol tea and coffee as 

 an article of Ibod. Recent chemical lesearch has 

 proved that the active principles of tea and coHee 

 — viz. theine and cafj'eine — are absolutely one and 

 the same body, perlectly identical in every respect. 

 The action of tea and coffee on the system must 

 be therefore the same. How is it that the prac- 

 tice of taking them has become necessary to whole 

 nations'? Cafleine (theine) is a highly nitro- 

 genized body. Bile, as is well known, contains 

 an essential nitrogenized ingredient — taurine. 



Now, Professor Liebig considers that caffeine goes 

 to the production of this taurine ; and, if an in- 

 fusion of tea contains only one-tenth of a grain of 

 cafl'eine, siill, if it contribute, in point of fact, to 

 the formation ol bile, the action even of such a 

 qnaniity cannot be looked upon as a nullity. 

 Neither can it be deni'd, that, in case of using an 

 excess of non-azotised Ibod, or deficiency of mo- 

 lion, which is required to cause the change of 

 matter in the tissues, and thus to yield nitrogenized 

 matter of the bile, that in such a condition the 

 state of health may be benefited by the use of 

 tea or coflee, by which may be furnished the ni- 

 trogenized product produced in the healthy stale 

 of the body, and essential lo the production of an 

 important element of respiration. The American 

 Indian, with his present habits of living solely on 

 flesh, could not with any comfort use lea as an 

 article of (ood ; for his tissues waste with such 

 rapidity, that, on (he contrary, he -has to take 

 something lo retard this waste. And it is worthy 

 of remark, that he has discovered in tobacco 

 smoke a means of retarding the change of matter 

 in the tissues of his body, and thereby of making 

 hunger more endurable. Nor can he withstand 

 the captivation of brandy, which, acting as an 

 element of respiration, puts a stop to the change 

 of matter, by performing the function which pro- 

 perly belongs to the products of the metamor- 

 phosed tissues. The third part of Liebig's report 

 treats of Ihe recondite laws of the phenomena of 

 motion ; but as it is principally of a speculative 

 character, we pass it over. The professor con- 

 cludes his valuable communication by two chap- 

 ters : one on the theory of disease ; the other on 

 Ihe iheory of respiration. The whole life of ani- 

 mals consists of a conflict between chemical forces 

 and the vital powers. In the normal state of the 

 body of an adult both stand in equilibrium. Every 

 mechanical or chemical agency which disturbs 

 the resioraiion of this equilibrium is a cause of 

 disease. Disease occurs when the resistance 

 offered by the vital Ibrce is weaker than the 

 acting cause of disturbance. Death is that con- 

 dition in which chemical or mechanical powers 

 gain the ascendency, and all resistance on the 

 part of the vital force ceases. Every abnormal 

 condition of supply or waste may be called dis- 

 ease. It is evident that one and the same cause 

 of disease — that is, of disiurbance — will have 

 diff'erent effects, according to the period of life. 

 A cause of disease, added lo the cause of waste, 

 may in old age annihilate the resistance of the 

 vital powers, or, in other words, occasion death; 

 while, in the adult slate, it may produce only a 

 disproportion between supply and waste; and 

 in inlaricy only an abstract state of health, i. e., 

 an equilibrium between supply and waste. Pro- 

 fessor Liebig argues, from what has preceded, 

 that a defii'iency of resistance in a living part to 

 the cause of waste is, in fact, a deficiency of re- 

 sistance to the action of the oxygen of the atmo- 

 sphere. The professor's theory may be compared 

 10 a sell-regulaiing steam engine. The body, in 

 regard to the production ol heat and of force, acta 

 just like one of those machines. With the lower- 

 ing of the external temperature, the respiration 

 becomes deeper and more frequent ; oxygen is 

 supplied in greater quantity, and of greater 

 density ; the change of matter is increased, and 

 more food must be supplied, if the temperature of 



