100 AZOTIC GAS. 



Atomic 2. I have been thus particular in determining 



weight of . -. * 



nitric acid the specific gravity of azote, because it is a ne- 

 ' cessary element in the investigation of its atomic 

 weight. We shall now determine the atomic 

 weight of nitric? acid, which is known to be a 

 compound of azote and oxygen ; and it contains 

 the greatest proportion of oxygen with which an 

 atom of azote is capable of uniting. Nitric acid 



Air is a compound of one atom of oxygen and two atoms azote ; or of 



Oxygen 1 or 22-22 



Azote 3-5 77-77 



100 



Let x = specific gravity of oxygen 22-22 = a 

 y = azotic gas 77-77 = b 



then *+ 4 ff 1 and x = 5 4 y 



o . 



4 a V 

 and x : 4 y : : a : b and x = - 



Hence 5 _4 = and y = = 0-9722 



and* = 5 4z/ = 5 3-8888= Mill 



I have thought it better to proceed as I have done in the text, because the 

 atomic weight of azote is most easily deduced from the specific gravity of 

 azotic gas. 



Berzelius and Dulong, in their paper on the specific gravity of gases, 

 give us the specific gravity of oxygen and azotic gases,' as follows : 

 Oxygen 1 -1026 



Azotic 0-9760 



Now, as air is a compound of 4 volumes azotic and 1 volume of oxygen 



1-1026 4- 0-9760 X 4 



gas, it is obvious that - - p - = specific gravity or com- 

 o 



mon air. If we resolve the equation, we find the specific gravity of com- 

 mon air not 1, as it ought to be, but 1-00132; showing that the specific 

 gravities of oxygen and azotic gases, as determined by these chemists, can- 

 not be correct. 



