CARBON. 147 



2. It was observed in a former part of this 

 chapter, that carbonic acid gas contains just its 

 own volume of oxygen gas. But to convert a 

 volume of carbonic oxide gas into a volume 

 of carbonic acid gas, we must add half a volume 

 of oxygen gas. It is evident from this, that a 

 volume of carbonic oxide gas contains just the 

 volume of carbon that carbonic acid gas does, 

 but only half the volume of oxygen gas. It 

 must therefore consist of one volume carbon va- 

 pour, and half a volume oxygen gas condensed 

 into one volume. 



1 volume carbon vapour weighs 0*4166' 

 volume oxygen gas. . . Q-5555 



0-9722 specific 

 gravity of carbonic oxide gas. 



3. A volume of carbon vapour being equiva- 

 lent to an atom, and half a volume of oxygen 

 gas to an atom, it is obvious that carbonic oxide 

 is a compound of one atom carbon, and one 

 atom oxygen. Hence its atomic weight is 1-75. 



Thus we have two compounds of carbon and 

 oxygen. 



CARBON. OXYGEN. 



Carbonic oxide composed of 1 atom -f- 1 atom 

 Carbonic acid ... 1 +2 



The last of these only possesses acid properties. 

 The first has no tendency whatever to unite 

 with alkaline bases. 



K 2 



