122 AZOTIC GAS. 



converted into nitrous acid, must have combined 

 with 41 '267 volumes of deutoxide of azote. 

 According to this experiment nitrous acid is 

 a compound of 







19'65 volumes of oxygen gas 

 41'267 volumes deutoxide of azote 



Or, 



20 volumes oxygen gas 



42 volumes deutoxide of azote 



42 exceeds 20 x 2 only by 2 volumes and these 

 2 volumes are absorbed by the air in the wa- 

 ter through which it was passed. This air al- 

 ways causes a little of the deutoxide of azote 

 to disappear, and renders its absorption in all ex- 

 periments made in this way a little greater than 

 the truth. 



From the preceding experiment, then, we may 

 conclude that nitrous acid is composed of 



1 volume oxygen gas 



2 volumes deutoxide of azote. 



But we have seen, in a preceding part of this 

 chapter, that deutoxide of azote is composed of 

 1 volume of azotic and 1 volume of oxygen gas, 

 united, without any condensation. It is obvious, 

 then, that nitrous acid is composed of 



1 volume azotic gas 



2 volumes oxygen gas. 



