OF BODIES CONTAINING NITROGEN. 335 



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 azotized animal matter is exposed 

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

 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 oxidation. 



Although w^e see the most simple means and direct 

 methods employed in the great processes of decom- 

 position 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 decomposition. 



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 charac- 

 ter to it, for the purpose of explaining a single 

 phenomenon, especially where the explanation of 

 that according to known facts offers no difficulty. 



The most distinguished philosophers suppose that 

 the nitrogen in an animal substance, w^hen exposed 

 to the action of air, water, and alkaline bases, 

 obtains the power to unite directly with oxygen, and 

 form nitric acid, but we are not acquainted with a 

 single fact which justifies this opinion. It is only 

 by the interposition of a large quantity of hydrogen 

 in the state of combustion or oxidation, that nitro- 

 gen can be converted into an oxide. 



When a compound of nitrogen and carbon, such 

 as cyanogen, is burned in oxygen gas, its carbon 

 alone is oxidized; and when it is conducted over a 

 metallic oxide heated to redness, an oxide of nitro- 



