Analysis of the compound inflammable Gases. 2 85 
ing number shews how much oxygen has been employed in 
the saturation of hydrogen. If, for example, 100 measures 
of carbureted hydrogen consume 200 of oxygen gas, and 
give 100 of carbonic acid, it follows, that the carbonic acid 
holds in combination 100 measures of the oxygen gas con- 
sumed ; and that the remaining hundred have been applied to 
the saturation of hydrogen. In this estimate it is assumed, 
that the carbon has acquired, by combustion, the whole of the 
oxygen necessary for its acidification, and that no part of it 
existed previously in the state of carbonic oxide, a proposition, 
in many cases, perhaps, very far from being consistent with 
the truth. This, however, admits of being decided by an ac- 
curate comparison between the weight of the gases consumed 
and that of the products. 
For the purpose of obtaining a general approximation to 
the nature of a combustible gas, it may be sufficient to exa- 
mine its coincidence with those, the properties of which have 
been already determined. The following table exhibits the 
results of the combustion of the few gases, that appear entitled 
to be considered as distinct species. They are deduced from 
the experiments of Mr. Cruikshank and Mr. Dalton. 
loo measures 
Kind of Gas. 
Sp. Grav. 
Take meas. 
Give carb. 
Are diminished 
(air — looo.) 
of oxygen. 
acid. 
by firing. 
Olefiant 
909 
300 
200 
200 
Carbonized hydrogen, from 7 
stagnant water, j 
600 
200 
100 
200 
Carbonic oxide 
967 
45 
90 
55 
Hydrogen gas 
84 
50 
J 54 
The inflammability of the compound gases, and their fitness 
for the purpose of affording light, are directly proportionate 
