OF BODIES CONTAINING NITROGEN. 807 



CHAPTER VIII. 



Eremacausis of Substances containing Nitrogen : Nitrification. 



When azotized substances are burned at high temperatures, their 

 nitrogen does not enter into direct combination with oxygen. 

 The knowledge of this fact is of assistance in considering the 

 process of the eremacausis of such substances. Azotized organic 

 matter always contains carbon and hydrogen, both of which 

 elements have a very strong affinity for oxygen. 



Now nitrogen possesses a very feeble affinity for oxygen, so 

 that it is placed, in regard to that element, in a position similar 

 lo that of the carbon of bodies containing much hydrogen during 

 their combustion ; a separation of the carbon of the latter sub- 

 stances in an uncombined state takes place, and in the same way 

 the substances containing nitrogen give out that element in its 

 gaseous form. 



When moist azotized animal matter is exposed to the action 

 of air, ammonia is constantly liberated ; nitric acid is never 

 formed under these circumstances. 



But when alkalies or alkaline bases are present, a union of 

 oxygen with the nitrogen takes place under the same circum- 

 stances, and nitrates are formed together with the other products 

 of oxidation. 



Although we see the most simple means and direct methods 

 employed in the great processes of decomposition occurring in 

 nature, still we find that the final result depends on a succession 

 of actions, which are essentially influenced by the chemical 

 nature of the bodies submitted to decomposition. 



When it is observed that the character of a substance remains 

 unaltered in a whole series of phenomena, there is no reason to 



