THE FARMERS' REGISTER. 



397 



obvious that the fuel necessary to retain iis heat 

 must vary in different climales. Thus less heai 

 is necessary in Pylermo, where the temperature 

 oi'the air is that of the human hoHy, than in the 

 polar regions, where it is aboui 90 liei^ites lower. 

 in the animal body the !bod is the luel, and by a 

 proper supply ol" oxygen we obtain the (ood ^iven 

 out during iis combudiion in win er. Whenvve 

 take exercif-e in a cold atmosphere, we respire 

 a greaier amountof oxygen, which implies a more 

 abundant supply of carbon in the lood ; and by 

 taking this lood we Ibrm the most efficient proiec- 

 tion against the cold. A starving man is soon 

 frozen to death and every one knows that the ani- 

 mals of prey of the Arctic regions are lar more vo- 

 racious than those of the torrid zone. Our cloth- 

 ing is merely an equivalent lor lood,. and the more 

 warmly we are clothed, the less food we require. 

 Were we to go destiiuteof clothes, like certain 

 savage tribes, — or il, in huming or fishing, we 

 were exposed to the same degree of cold as the 

 Samoyedes, — we could with ease consume lOlbs. 

 of flesh, and perhaps a dozen tallow candles to the 

 bargain, as warmly-dad travellers have related 

 with astonishment of those people.* Then could 

 we take the same quantity of brandy or blubber o; 

 fish without bad effects, ami learn to appreciate 

 the delicacy of train-oil. We thus perceive an 

 explanation of the apparently anomalous habits 

 of different nation?. The maccaroni of the Italian, 

 and the train-oil of the Greenlander and the Rus- 

 sian, are not adventiiious Ireaks of taste, but ne- 

 cessary articles fiited to administer to their com- 

 fort in the climates in which they have been born; 

 and the colder the region the more combustible 

 must the food be. The Englishman in Jamaica 

 perceives with regret the disappearance ol'his ap- 

 petite, which in Enijland had been a con.-5tani re- 

 curring source of enjoyment ; by the use of aro- 

 matics he creates an ariificial appetite, arid eats as 

 much (bod as he did at home ; but he thus unfits 

 himself' (or the climate in witich he is placed ; (br 

 sufRoient oxygen does not enter his sysiem to 

 combine with the carbon consumed, and ihe heat 

 of the climaie prevents him taking exeri l^;e to in- 

 crease the number of his respirations. The car- 

 bon of (bod is there(bre (breed into other channels 

 and disease results. England, on the oiher hand, 

 sends her dyspeptic patients to southern climates. 

 In our own land their impaired digestive organs 

 are unable to fit the (bod (or that state in which it 

 best unites with the oxygen of the air, which 

 therefore acts on the organs of respiration them- 

 selves, thus producing pulmonary complaints ; but 

 when they are removed to warmer climates they 

 absorb less oxygen and take less (bod, and tITe 

 diseased organs of digestion have sufficient power 

 to place the diminished amount of Ibod in equili- 

 brium with the respired oxygen; just as we 

 would expect from these views, in our own climate, 

 hepatic diseases, or diseases arising from excess 

 of carbon, are more prevalent in summer, and in 

 winter pulmonic diseases, or those arising from an 

 excess o( oxygen. The professor then went on to 

 disprove the notion that animal heat is due to 

 nervous influence and not to combustion — an error 

 which had its origin in supposing that the com- 



* A sportsman or traveller in the Highlands of Scot- 

 land knows how much more he can whisky it, &c., than 

 in (he south. 



bustion proceeds in the blood itself. He also 

 showed that animal heat must not be ascribed to 

 the contraction of the muscles, but that the heat 

 evolve(i by the combustion of carbon in the body 

 IS suflicieiu u) accuuni (or the phenoiuena of ani- 

 mal heat. He showed that the 14 ounces of car- 

 bun which are daily converted into carbonic acid 

 in an adult disengage no less than 197.4770 of 

 heat ; a quantity which would convert 24 lbs. of 

 water, at ihe temperature of the body, into vapor: 

 and if we assume that the quaniiiy of water 

 vaporized through the skin and lungs amounts to 

 3 lbs. then we have still 146.380° of heat to sustain 

 the temperature of the body. And when we take 

 into calculation the heat evolved by the hydrogen of 

 the Ibod, and the small specihc heal possessed by 

 the organs generally, no doubt could be entertained 

 that the heat evolved in the process of combustion, 

 to which the fooil is subjected in the body, is amply 

 sufficient to explain the constant temperature of the 

 body. From what has preceded, il is obvious that 

 the amount of carbon consumed in'lood ought to de- 

 pend on the climate, density of air, and occupation 

 of the individual. A man will require less carbon 

 when pursuing a sedentary occupation than when 

 he isengaged in active exercise. Professor Liebior, 

 having thus discussed the source of animal heat, 

 proceeds next to consider what are the ingredients 

 in the food which may properly be considered to 

 he nutritious. Physiologists conceive that the 

 various organs in the body have originally been 

 formed from blood. If this be admitted, it is ob- 

 vious that those substances only can be considered 

 as nutritious which are susceptible of being trans- 

 lormed into blood. The professor then entered 

 upon an examination of the composition of blood, 

 and of the identity in chemical composition of 

 fibrine and albumen. The nutritive process is 

 simplest in the case of the carnivora. This class 

 of animals live on the blood and flesh of the gra- 

 minivora, whose blood and flesh are identical with 

 their own. In a chemical sense, therefore, a car- 

 nivorous animal, in taking Ibod, leeds upon itself; 

 fbr the nutriment is identical in composition with 

 its own tissues. He next inquired, li-om what 

 constituents of vegetables the blood of the grami- 

 nivorous animals is produced. The nitrogenized 

 compounds of vegetables forming the (bod of 

 graminivorous animals are called vegetable fibrine, 

 vegetable albumen, and vegeiable caseine. Now, 

 analysis has led to the interesting result, that they 

 are exactly of the same composition in 100 parts ; 

 and, what is still more extraordinary, they are ab- 

 solutely identical with the chief constituents of 

 the blood — animal fibrine and animal albumen. 

 By identity, be it remarked, we do not imply simi- 

 larity, but absolute identity, even as far as their 

 inorganic constituents are concerned. These con- 

 siderations showed the beautiful simplicity of nu- 

 trition. In point of fact, vegetables produce, in 

 their inorganism, the blood of all animals. Ani- 

 mal and vegetable life are therefore most closely 

 connected. The professor has still to account for 

 the use of the substances in (bod which are abso- 

 lutely destitute of nitrogen, but which we know 

 are absolutely necessary to animal life. In all 

 these we find a great excess of carbon, and but 

 very little oxygen. By a train of admirable rea- 

 soning, he arrives at the interesting conclusion, 

 that they are solely exhausted in the production 

 of animal heat, being converted by the oxygen of 



