246 GASEOUS BODIES. 



ceding table. The compound gases in the pre- 

 ceding table may be considered as consisting of 

 a volume, or a determinate number of volumes 

 of each constituent, so condensed, that a volume 

 of the compound gas bears the same relation to 

 a volume of oxygen gas, as a volume of hydrogen 

 gas does to a volume of oxygen gas ; but there 

 are four compound gases, which consist of a vo- 

 lume of each of the constituents united together, 

 without any condensation whatever. Conse- 

 quently, their specific gravities, instead of being 

 equal to the specific gravities of all their consti- 

 tuents added together, are only the means of the 

 specific gravities of the constituents. In reality, 

 therefore, the volumes of these gases may be 

 considered as doubled, with reference to their 

 atomic weights. These gases are deutoxlde of 

 azote, hydrocyanic acid vapour, muriatic acid, 

 and liydriodic acid. 



(1.) Deutoxide of azote is composed of 1 vo- 

 lume of oxygen gas, and 1 volume of azotic gas, 

 united together, without any alteration of vo- 

 lume ; hence its specific gravity is the mean of 

 the specific gravities of oxygen and azotic gases, 

 or 1-0416. 



(2.) Hydrocyanic acid, muriatic acid, and hy- 

 driodic acid, are composed respectively of one vo- 

 lume of hydrogen gas, united to a volume of 

 cyanogen, chlorine, and iodine vapour, without 

 any condensation. 



