Note 75 — Chapter VI
Reading edition
The most complete exposition of the theory that animal heat is derived from chemical action only, will be found in Animal Chemistry, or Chemistry in its applications to Physiology and Pathology, by Justus Liebig: translated by Dr. Gregory. The conclusions arrived at by the author, notwithstanding his high—and deservedly high—position in chemical science, must, however, be received with great caution, many of them being founded on most incorrect premises, and his generalizations being of the most hasty and imperfect character. At page 22 the following passage occurs:—“If we were to go naked, like certain savage tribes, or if in hunting or fishing we were exposed to the same degree of cold as the Samoiedes, we should be able, with ease, to consume ten pounds of flesh, and, perhaps, a dozen of tallow candles into the bargain, daily, as warmly clad travellers have related with astonishment of these people. We should then also be able to take the same quantity of brandy or train-oil without bad effects, because the carbon and hydrogen of these substances would only suffice to keep up the equilibrium between the external temperature and that of our bodies.”
A brief examination will exhibit the error of this. The analysis of Beef, by D. Lyon Playfair, is as follows:—
Carbon51·83
Hydrogen7·57
Nitrogen15·01
Oxygen21·37
Ashes4·23
And the following has been given by Chevreul as the composition of mutton tallow:—
Carbon96
Hydrogen16
Nitrogen16
Oxygen48
About three times the quantity of oxygen to the carbon eaten, is required to convert it into carbonic acid; hence, the Samoiede, eating more highly carbonized matter, must inspire 288 oz. of oxygen daily, or nearly eight times as much as the “ordinary adult.” By the lungs he must take into the body 2,304 cubic feet of air besides what will be absorbed by the skin. His respirations must be so much quickened, that at the lowest possible calculation he must have 500 pulsations a minute. Under such conditions it is quite clear man could not exist. There is no disputing the fact of the enormous appetites of these people; but all the food is not removed from the system as carbonic acid gas.