396 



THE FARMERS' REGISTER. 



Plants subsisted entirely upon manures belonging 

 to inorganic nature. Ainiospheric nir, ihe source 

 wiience they derived liieir nutriment, was consi- 

 dered to be a mineral by the most dieiinguisbed 

 mineraiogisis. All eubsiancee, belbre they could 



and are emitted into the atmosphere. No part 

 ol ihe oxygen nispired is again expired as such. 

 Now, it is lountl that an adult inspires 32^ ounces 

 oC oxygen daily ; this will convert the carbon of 

 24 lbs. ol blood into carbonic acid. He must 



form lou^i lor plants, must be resolved imo organic iherelore take as much nutriment as will supply 

 mailer: but animals, un the other hand, required (his daily luss ; and, in lact, it is lound that he 

 highly organized atoms lor nutriment. They dues so ; lor the average amount oi carbon in the 

 could only subsist upon parts ot an organism, duily luod ol' i-.n adult man, inkiiii.' moderate exer- 

 They possessed vvith'U them a vegetable hie, as cise, is 14 oz. which require 37 oz. o! oxygen lor 

 plants did, by means of which ihey increased in their conversion into carDomc acid. But it is 

 size, without consciousness on their pan; but i obvious, as the inspired oxygen can be removed 

 ihey were distinguished I'roiu vegetables by iheir j only by its conversion into carbonic acid and water, 

 faculties ol locomoiion and sensation — lacultiee that the amount ol lood necessary lor ihe support 

 aciinf ihrougli a nervous apparatus. The true ol' ihe animal body must be in direct ratio to the 

 venerable lile^ol' animals was in no way depend- quantity ot oxygen taken into the system. Thus 



em upon this ajiparaius, lor it proceeded when 

 the means of voluntary motion and sensation 

 were destroyed; and the most energetic volition 

 was incapable oi' exerting any influence on the 

 contractions ot the heart, on the motion of ihe 

 intestines, or on the processes of secretion. All 

 parts of the animal body were produced from the 

 fluid circulating within lis organism, by virtue ot 

 vitality, which resided in every organ. A de- 

 struction of the animal body was constantly pro- 

 ceeding. Every motion, every manifestation ol 

 Ibrcc, was the result of the transtormalion oi ihe 

 structure, or of its substance. Every conception, 

 eveiy menial affection, was followed by changes 

 in the chemical nalure of the secreted fl^iids. 

 Every thought, every sensation was accompanieii 

 by a chaniie in the composition of the subsiance 

 Ol the brain. Il was lo s-upply the waste thus 

 produced, ihat food became necessary. Food 

 was either applied in the increase of the mass ol 

 a structure (i. e. in nutrition,) or was applied in 

 the replacement of a siruciure wasted (i. e. in 

 reproduction.) The primary condition lor the 

 existence of life was the reception and assimi 



a child, in vvliom the organs of respiration are 

 naturally in aolate ol great activity, requires food 

 more Irequenily and in greater proporiions to its 

 bulk than an adult, and is also less patient of hun- 

 ger. A bird, deprived oi lood, dies on ihe third 

 day ; whilsi a serpent, which inspires a mere 

 irace ol oxygen, can live without lood for three 

 months. The capacity of the chest in an animal 

 is a constant quantity; we therelore inspire the 

 same volume ot air whether at the pole or the 

 equaior ; bui the weight of the air, and conse- 

 quenily of !he oxygen, varies wiih ihe tempera- 

 lure. Thus an adult man lakes into ihe system 

 daily 46,000 cubic inches of oxygen, which, il'the 

 temperaiure be 77°, weigh 32^ oz., but when the 

 lemperaiure sinks down lo the Ireezing-point 

 (32°,) it will weight 35 oz. Thus an adult in our 

 clitnaie in winter may inhale 35 oz. ot oxygen : in 

 Sicily he would inb.|)ire only 28| oz. ; a«d if in 

 Sweden, 3(5 oz. Hence we inspire more carbon 

 in cold weather, when the barometer is high, than 

 we do in warm weather ; and we must consume 

 more or less carbon in our food in the same pro- 

 portion. In our own climate the difierence be- 



lation of lood. But there was another condition | ivveen summer and winter in the carbon expired, 

 equally importbnt — the continual absorption ol I and iherelore necessary lor lood, i^ as much as an 



oxygen from the atmosphere. All vital activity 

 resulted from the mutual action of the oxygen of 

 the atmosphere and the elements of ihe lood. 

 All changes in matter proceeding in the body 

 were essentially chemical, although they were 

 not unfrequently increased or diminished in in- 

 tensity by the vital lorce. The influence of poi- 

 sons and remedial agents on the animal economy 



eighth. Even when we consume equal weights 

 of lood, an infinitely wise Creator has so adjusted 

 It as to meet the exigencies of climate. Thus the 

 fruit on which the inhabitants of the south delight 

 to teed contains only 12 per cent ol cnrbon, whilst 

 the bacon and train-oil enjoyed by the inhabitants 

 of the Arctic regions contain from 66 lo 80 per 

 cent, ol the same element. Now the mutiml ac- 



pioved, that the chemical combinations and de- lion between the elements of lood and the oxygen 

 compositions proceeding therein, and which mani- of the air is the source of animal hent. All '■■■■-- 



lested themselves in the phenomena of viialiiy, 

 might be influenced by bodies having a well de- 

 fined chemical action. Vitality was the ruling 

 agent by which the chemical powers were made 

 to subfcerve its purposes ; but the acting lorces 

 were chemical. Ii was I'rom this view, and no 

 other, that we outjlit lo view vitality. 



According to Lavoisier, an adult man takes 

 into his system every year 837 lbs. of oxvgen, 

 and yet he does not increase in weight. What 

 then becomes of the enormous quantity of oxy- 

 gen introduced in the course of the year into 

 the human system? The carbon and hydrotjen 

 of certain parts of the body have entered into 

 combination with the oxygen introduced through 

 the lungs and through the ekin, and have been 

 given out in the (brm of carbonic acid and the 

 vapor of water. At every moment, with every 

 expiration, parts of the body are thus removed. 



creatiiro-s, whose existence depends on (he absorp- 

 lion of oxygen, possess within themselves a source 

 of heat iiulej)eiident ol the medium in which they 

 exist ; this heat, in Prolessor Liebig's opinion, is 

 wholly due lo the combustion of the carbon and 

 hydrogen contained in the food which they con- 

 sume. Animal heat exists only in those parts of 

 the body through which arterial blood (and with 

 it oxygen m solution) circulates. The carbon and 

 hydroiien of lood, in being converted by oxygen 

 iuio carbonic aciil and water, must give out as 

 much heal as if they were burned in the open air; 

 the only diflerence is, that this heat is spread over 

 unequal spaces of time, but the actual amount is 

 always the same. The temperature of the humam 

 body is the same in the torrid as in the frigid zone ; 

 but as the body liiay be considered in (he light of 

 a heated vessel, which cools with an accelerated 

 apidity, the colder the surrounding medium, it is 



