150 ACIDIFIABLE COMBUSTIBLES. 



carbon and two atoms hydrogen. This is the 

 same thing as one atom carbon and one atom 

 hydrogen. Consequently, this gaseous compound 

 ought to be distinguished by the name of car- 

 buretted hydrogen, had not that name, unfortu- 

 ately, been previously appropriated to a different 

 gas. 

 Five gases j$ u t this combination of carbon and hydrogen, 



exist com- J 



posed of atom to atom, in the gaseous state, deserves to 



equal atoms 



of carbon fix our particular attention. I believe that no 

 gen. y r fewer than five different gases or vapours exist, 

 composed of these two substances in that pro- 

 portion, but coupled together in different ways. 

 First sp e. The first consists of 



cies. 



1 volume carbon vapour l 



IT., > condensed into 1 volume. 



1 volume hydrogen gas. f 



Its specific gravity is 6*4861. One volume of 

 it requires for complete combustion, 1| volume 

 of oxygen gas. After the combustion there re- 

 mains one volume of carbonic acid gas. 



This peculiar gas has not yet been met with 

 by chemists ; but I see no reason to doubt its 

 existence. It probably exists occasionally as a 

 constituent of coal gas. 

 Second The second is olefiant gas, composed of 



species. 



2 volumes carbon vapour 1 



, , , > condensed into 1 volume. 



2 volumes hydrogen gas ) 



Its specific gravity is O9722. One volume of 

 it requires for complete combustion three vo- 



