172 On the aériform Compounds 
TaBLx III. exhibiting the Characteristic Properties of different 
Names of Gases. 
Olefiait gas 
Hydrogen gas 
Carbonic oxide 
As an illustration of the method of investigating the propor- 
tions of mixtures of the three last gases, we may take the instance 
of a mixed gas, free from olefiant gas, of specific gravity 534, 
of which 100 volumes consume 110 of oxygen, and afford 70 of 
carbonic acid, the diminution of the whole 210 after firing being 
140 volumes. Now it must be obvious from inspection of the 
Table, that the 70 parts of carbonic acid cannot all have resulted 
from the combustion of carburetted hydrogen, since, for the sa- 
turation of 70 measures of that gas, 140 of oxygen would have 
been required, whereas only 110 have been expended. We may 
therefore safely infer the presence of carbonic oxide, a gas which, 
by combustion, gives its own volume of carbonic acid, with the 
expenditure of only half its volume of oxygen. The specific gra- 
vity of the specimen being lower‘than that of garburetted hydro- 
gen, indicates also an admixture of simple hydrogen gas; and of 
this the proportion must necessarily be considerable, to coun- 
tervail the weight of the heavy carbonic oxide. The following 
proportions of the three gases will be found to coincide with the 
properties of the mixture. 
Consume Ox. Give Carb. Ac. Dimin. by firing 
40 vols. of carb. hydrogen 80 40 80 > 
30 carb. oxide 15 30 15 
30 hydrogen gas) 15 0 Ad 
100 110 70 140 
No reliance, however, can be placed on the accuracy of. such 
estimates, unless the specific gravity of the specimen agrees with 
that of the hypothetical mixture, as deduced from the proportion 
of its ingredients. But when this coincidence takes place, we 
have all the evidence, which the subject at present admits, of 
the nature of the mixture; and as this agreement between ex- 
periment and calculation was found to take place very nearly, in 
all the instances comprehended jn the two following Tables, we 
may consider the numbers composing them, as expressiog, with 
sufficient exactness, the relative proportion of different gases in 
the residues of gil and coal gas left by the action of chlorine. 
TABLE - 
