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



These ferments, which have so powerfully attracted our 

 'attention, and which preside over the most remarkable me- 

 tamorphoses of organic chemistry, 1 reserve for the next year, 

 when I shall give you a still more particular and full account 

 of them. 



Thus we discharge urea accompanied by this ferment, by 

 this artifice, which acting at a given moment, turns this urea 

 into carbonate of ammonia. 



If we restore to the general phenomenon of animal com- 

 bustion that carbonic acid of the carbonate of ammonia which 

 of right belongs to it, there remains ammonia as the charac- 

 teristic product of urine. 



Thus, By the lungs and the skin, carbonic acid, water, azote ; 

 By the urine, ammonia. 



Such are the constant and necessary products which exhale 

 from the animal. 



These are precisely those which vegetation demands and 

 makes use of, just as the vegetable in its turn gives back to 

 the air the oxygen which the animal has consumed. 



Whence come this carbon, this hydrogen burnt by the 

 animal, this azote which it has exhaled in a free state or 

 converted into ammonia? They evidently come from the 

 aliments. 



By studying digestion in this point of view, we have been 

 led to consider it in a manner much more simple than is 

 customary, and which may be summed up in a few words. 



In fact, as soon as it was proved to us that the animal cre- 

 ates no organic matter; that it merely assimilates or expends 

 it by burning it (en la brillant), there was no occasion to seek 

 in digestion all those mysteries which we were quite sure of 

 not rinding there. 



Thus digestion is indeed but a simple function of absorp- 

 tion. The soluble matters pass into the blood, for the most 

 part unchanged ; the insoluble matters reach the chyle, 

 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. 



