OF BODIES CONTAINING NITROGEN. 277 



organic matter always contains carbon and hydro- 

 gen, both of which elements have a very strong 

 affinity for oxygen. 



Now nitrogen possesses a very feeble affinity for 

 that element, so that its compounds during their 

 combustion present analogous phenomena to those 

 which are observed in the combustion of substances 

 containing a large proportion of hydrogen and car- 

 bon ; 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 a moist azotised animal matter is exposed 

 to the action of the air, ammonia is always liberated, 

 and nitric acid is never formed. 



But when alkalies or alkaline bases are present, 

 a union of oxygen with the nitrogen takes place 

 under the same circumstances, and nitrates are 

 formed together with the other products of oxi- 

 dation. 



Although we see the most simple means and 

 direct methods employed in the great processes of 

 decomposition which proceed 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 decom- 

 position. 



When it is observed that the character of a sub- 

 stance remains unaltered in a whole series of phe- 

 nomena, there is no reason to ascribe a new cha- 



