146 ACIDIFIABLE COMBUSTIBLES. 



low. Berzelius and Dulong state its specific 

 gravity to be 0*9727. This is rather too high ; 

 but it is a good deal nearer the truth than mine. 



When 1 00 volumes of this gas are mixed with 

 50 volumes of oxygen gas, and an electric spark 

 passed through the mixture, combustion takes 

 place, both gases disappear, and a quantity of 

 carbonic acid gas is formed just equal to the ori- 

 ginal volume of the carbonic oxide gas employed. 

 This fact, which has been sufficiently established 

 by experiment, will enable us to determine the 

 true specific gravity of this gas, and likewise its 

 constituents and its atomic weight. 



1. Since half a volume of oxygen gas added 

 to one volume of carbonic oxide gas constitutes 

 one volume of carbonic acid gas, it is obvious 

 that, if from the specific gravity of carbonic acid 

 gas, we subtract half the specific gravity of oxy- 

 gen gas, the remainder will be the specific gra- 

 vity of carbonic oxide gas. 



Sp. gr. of carbonic acid gas = 1-5277 

 sp. gr. of oxygen gas == 0-5555 



0-9722 == sp. gr. of 

 carbonic oxide gas. 



Thus we learn, that the specific gravity of this 

 gas is 0-9722*, or exactly the same with that of 

 azotic gas. The specific gravity of it as given 

 by Berzelius and Dulong, exceeds the truth by 

 little more than vdtn part. 



