AZOTIC GAS. Ill 



give us the weight of azote in this quantity of 

 nitric acid, and the remainder of the weight 

 must be oxygen ; consequently, nitric acid is 

 composed of 



Azote 0-296527 or 1-7477 Composi- 



Oxygen 0-848824 - 5 % 



1-144852 6-7477 



But there is obviously a slight inaccuracy in this 

 analysis, for it gives us the atomic weight of ni- 

 tric acid 6 '7^77 > instead of 6*75, which we found 

 above to be the true quantity. It is clear, that 

 this error lies in the azote, which is a little too 

 low, and not in the oxygen, which must consti- 

 tute a whole number of atoms. Had I obtained 

 from 8-65 grains of nitre 4*004 cubic inches of 

 azotic gas, instead of 4 cubic inches, this error 

 would not have existed. But my apparatus was 

 not delicate enough to measure the gas evolved 

 so exactly I may, in reality, have obtained 

 4*004 cubic inches, without perceiving the slight 

 difference in volume. 



There can be no doubt, from these experi- 

 ments, that the true composition of nitric acid is 



Azote 1-75 

 Oxygen 5 



6 ' 75 Weight of 



^ the atom of 



Ur it is composed of 1 atom of azote and 5 azote. 



