AZOTIC GAS. 117 



Its specific gravity is obviously obtained by 

 adding together the specific gravity of azotic gas, 

 and half the specific gravity of oxygen gas. 



Specific gravity of azotic = 0-9722 

 J specific gravity of oxygen = 0-5555 



1-5277 



I took the specific gravity of this gas three 

 times successively, and obtained each time 

 1%5269 This is as near an approximation to 

 the truth as I could reach with my balance 

 and is amply sufficient to satisfy us, that the 

 specific gravity above deduced, from the known 

 specific gravities, volumes, and condensation of 

 its two constituents, is correct. 



2. Deutoxide of azote, the nitrous air of Analysis of 

 Priestley, has been long known, and for many O f azote, 

 years constituted a favourite object of research 

 among chemists. Sir H. Davy was the first per- 

 son who attempted an accurate analysis of it. 

 From his experiments .(Researches, p. 122.) it 

 was evident, that it consisted very nearly of equal 

 volumes of oxygen and azotic gases. Gay-Lus- 

 sac afterwards demonstrated, that its constituents 

 are 1 volume of oxygen, and 1 volume of azotic 

 gases, united together without any condensation. 

 He heated some potassium in 100 volumes of 

 this gas ; after the combustion was at an end, 

 and the whole apparatus cooled down to the 



H3 



