558 DULONG AND DESPRETZ. 



quantity of oxygen consumed by respiration. But 

 on repeating their experiments, by surrounding 

 animals with water, and comparing the elevation 

 of its temperature with the amount of oxygen 

 consumed, Dulong and Despretz inferred that 

 from 9 to 25 per cent, more caloric was im- 

 parted to the water than could be accounted 

 for by the absorption of oxygen, (in accordance 

 with the theory of Lavoisier and Laplace,) allow- 

 ing it to combine with carbon and hydrogen ; 

 and that in no case did respiration afford more 

 than -^ths of the heat given off by the animal. 

 M. Despretz, therefore, concludes that respira- 

 tion is the principal source of animal tempera- 

 ture, but that a small remaining portion (petite 

 portion restante) is generated by motion of the blood, 

 friction, assimilation, &c. (Ann. de Chim. et de 

 Phys. t. 26.) 



But it is scarcely possible to believe, that 

 animals could remain from one hour and a half 

 to two hours surrounded with water, without 

 losing more caloric than they gain from the 

 atmosphere by breathing, or that they should 

 not undergo a reduction of temperature ; and if 

 it were established that they give out T Vth more 

 caloric, in proportion to the amount of oxygen 

 consumed, than is evolved during the union of 

 the same quantity of oxygen with carbon and 

 hydrogen out of the body, I should still maintain 

 that the process of combustion, by which animal 

 life is supported, is perfect ; whereas that of the 



