OF ANIMAL HEAT. 33 



from 32 to 195563-3; or to cause 67-9 Ibs. of wa- 

 ter at 32 to boil; or to heat 184-3 Ibs. of water to 

 98-3 (the temperature of the human body) ; or to 

 convert into vapor 11-4 Ibs. of water at 98-3. 



If we now assume, that the quantity of water vapor- 

 ized through the skin and lungs in 24 hours amounts to 

 48 oz. (3 Ibs.), then there will remain, after deducting 

 the necessary amount of heat, 144137-7 * degrees of 

 heat, which are dissipated by radiation, by heating the 

 expired air, and in the excrementitious matters. 



In this calculation, no account has been taken of the 

 heat evolved by the hydrogen of the food, during its 

 conversion into water by oxidation within the body. 

 But if we consider, that the specific heat of the bones, 

 of fat, and of the organs generally, is far less than that 

 of water, and that consequently they require, in order 

 to be heated to 98-3, much less heat than an equal 

 weight of water, no doubt can be entertained, that when 

 all the concomitant circumstances are , included in the 

 calculation, the heat evolved in the process of combus- 

 tion, to which the food is subjected in the body, is 

 amply sufficient to explain the constant temperature of 

 the body, as well as the evaporation from the skin and 

 lungs. 



VI. All experiments hitherto made on the quantity 

 of oxygen which an animal consumes in a given time, 

 and also the conclusions deduced from them as to the 



* In the above, the latent heat of vapor at 212 is taken, according 

 to Despretz, at 955.8. 



