466 M. Dumas on the Chemical Statics of Organized Beings. 



sufficiently divided to be taken up by the orifices of the chyli- 

 ferous vessels. 



Besides, the evident object of digestion is to restore to the 

 blood a matter proper for supplying our respiration with the 

 ten or fifteen grains of coal, or the equivalent of hydrogen 

 which each of us burns every hour, and to restore to it the 

 grain of azote which is also hourly exhaled, as well by the 

 lungs or the skin as by the urine. 



Thus the amylaceous matters are changed into gum and 

 sugar; the saccharine matters are absorbed. 



The fatty matters are divided, and converted into an emul- 

 sion, and thus pass into the vessels, in order to form depots 

 which the blood takes back and burns as it needs. 



The neutral azotated substances, fibrin, albumen and ca- 

 seum, which are at first dissolved, and then precipitated, pass 

 into the chyle greatly divided or dissolved anew. 



Theanimal thus receives and assimilates almost unaltered the 

 azotated neutral substances which it finds ready formed in the 

 animals or plants upon which it feeds ; it receives fatty matters 

 which come from the same sources ; it receives amylaceous 

 or saccharine matters which are in the same predicament. 



These three great orders of matters, whose origin always 

 ascends to the plant, become divided into products capable 

 of being assimilated, fibrin, albumen, caseum, fatty bodies, 

 which serve to renew or recruit the organs with the com- 

 bustible products, sugar and fatty bodies which respiration 

 consumes. 



The animal therefore assimilates or destroys organic mat- 

 ters ready formed ; it does not create them. 



Digestion introduces into the blood organic matters ready 

 formed ; assimilation employs those which are azotated ; 

 respiration burns the others. 



If animals do not possess any peculiar power for producing 

 organic matters, have they at least that special and singular 

 power which has been attributed to them of producing heat 

 without expenditure of matter ? 



You have seen, while discussing the experiments of MM. 

 Dulong and Despretz, you have positively seen the contrary 

 result from them. These skilful physicists supposed that an 

 animal placed in a cold water calorimeter comes out of it with 

 the same temperature that it had on entering it ; a thing abso- 

 lutely impossible, as is now well known. It is this cooling of 

 the animal, of which they took no account, that expresses in 

 their tableaux the excess of heat attributed by them and by all 

 physiologists to a calorific power peculiar to the animal and 

 independent of respiration. 



