viii THE BURNING OF INFLAMMABLE GASES 141 



the volume of carbonic anhydride produced in the 

 explosion, and concluded that, whilst carbonic anhydride 

 contained 28% of carbon, the inflammable oxide contained 

 53% of carbon and 47% of oxygen (" On the Reduction of the 

 White Oxide of Zinc by Carbon, and on the Gaseous Oxide of 

 Carbon which is produced." Ann.de Chimie, 1801, 39, 26-64.) 



Desormes and Clement prepare carbonic oxide by the 

 reduction of carbonates. Having established the nature of 

 the gaseous oxide, De'sormes and Clement proved that the 

 same gas is formed during the reduction with charcoal of 

 refractory carbonates, such as that of baryta. This carbon- 

 ate resembles chalk in that it effervesces when acids are 

 added to it ; but it differs from chalk in that it is not readily 

 decomposed by heat. Whereas carbonated magnesia can 

 be decomposed in glass vessels, and chalk in an earthenware 

 retort (Ch. IV., p. 49), carbonated baryta must be decom- 

 posed by heating with charcoal-, the fixed air is then 

 reduced and escapes in the form of carbonic oxide. It 

 should be noted that Cruikshank prepared carbonic oxide 

 from the same carbonate by the action of iron (p. 140). 



Desormes and Clement describe their experiments as 

 follows : 



" The preceding experiments show that the gas generated 

 by the reduction of oxide of zinc, was only oxygen and 

 carbon which, meeting at a high temperature, combined in 

 different proportions from those of carbonic acid. It 

 seemed possible to form this combination by uniting carbon 

 and carbonic acid. 



" One recalled the experiment of Pelletier who, by the 

 addition of charcoal to carbonate of baryta, succeeded in 

 driving out the carbonic acid from it by simple heat, and 

 one believed that in this experiment the carbonic acid 

 combining with the carbon, had formed a gas similar to 

 that obtained in the reduction of oxide of zinc, and was 

 separated easily from the baryta on account of its greater 

 elasticity. 



