Dr . Thomson on Oxalic Add. 
77 
every compound inflammable gas which I have examined. 
This difference makes it impossible to use both extremes of 
the series : I make choice of that in which the proportion of 
oxygen is considerable, as upon the whole more satisfactory. 
The best proportion is one part of the gas and two parts of 
oxygen. The oxygen ought not to be pure, but diluted with 
at least the third of its bulk of azote, unless the gas be much 
contaminated with common air. 
I have elsewhere detailed the method which I follow in 
analyzing gases of this nature.* The following table exhibits 
the mean of a considerable number of trials of this gas with 
oxygen. 
Measures of 
inflammable Air 
consumed. 
Measures of 
Oxygen con- 
sumed. 
Carbonic Acid 
formed. 
Diminution of 
Bulk. 
100 
91 
93 
98 
that is to say, 1 oo cubic inches of the gas when burnt, com- 
bine with 91 cubic inches of oxygen ; there are produced 93 
inches of carbonic acid ; and after the combustion these 93 
inches alone remain, the rest being condensed. Hence we 
conclude that the other substance produced was water. 
This result corresponds almost exactly with what would 
have been obtained, if we had made the same experiment 
upon a mixture of 70 measures of carbonic oxide, and 30 
measures of carbureted hydrogen, as will appear from the 
following table. 
* See Nicholson’s Journal, 16. 247* 
