296 Dr. Henry’s Description of an Apparatus for the 
The remainder, being mingled with one fourth its bulk of 
oxy-muriatic acid gas, the mixture lost 10.4 measures. This 
diminution, 10.4, divided by 2.2, gives 4.9 for the proportion 
of olefiant gas. But 100 measures of the unwashed gas sus- 
tained, by admixture with oxy-muriatic acid, a diminution 
of 20 measures. Now, deducting, from this diminution, that 
occasioned by the condensation of olefiant gas, (viz. 20 — 
10.4,) there remain 9.6, which, divided by 1.8, gives 5.3 for 
the proportion of sulphureted hydrogen gas. And the dimi- 
nution by potash ( = 9.7 ) — 5.3 gives 4.4 for the proportion 
of carbonic acid gas. Hence 100 measures of the first pro- 
duct of gas from cannel coal contain, 
1. Of inflammable gas, not affected by the 
foregoing agents 
2. Of sulphureted hydrogen gas, - 5.3 
3. Of olefiant gas - - 4.9 
4. Of carbonic acid gas - - - 4.4 
100 
The proportion of common air, in the foregoing specimen 
of gas, and in all cases when care was taken to exclude it, was 
too small to deserve being taken into the account, not appear- 
ing, by the test of nitrous gas, to exceed 1 per cent. 
The following table exhibits the composition of gas from 
various kinds of coal. In the last column, under the term in- 
flammable gas, is comprehended that portion, which is neither 
suddenly condensed by oxy-muriatic acid gas, nor absorbed by 
potash. A name more descriptive cannot be applied to it, 
because it varies essentially in different cases, and the propor- 
tion of its components is still matter of doubt. 
