295 
Analysis of the compound inflammable Gases . 
mixture, is a problem of some difficulty. Sulphureted hydro- 
gen and olefiant gases experience, it is well known, an imme- 
diate condensation, when mingled with oxy-muriatic acid gas, 
and in this way they may be separated from carbonic acid. 
Again, sulphureted hydrogen and carbonic acid are absorbed 
by liquid potash, which has no action on olefiant gas. If, 
therefore, two equal portions of the gas from coal be mixed 
with oxy-muriatic gas, the one in its recent state, the other 
after being washed with potash, the condensation of the for- 
mer will be found to exceed that of the washed portion. By 
the combined use of these agents, we may attain an approxi- 
mation, at least, to the proportions in which carbonic acid, 
olefiant, and sulphureted hydrogen gas are mingled with the 
aeriform product of coal. The rule may be stated as follows ; 
to a measured quantity of oxy-muriatic acid gas, contained in 
a graduated tube, add twice its bulk of the recent coal gas, and 
at the expiration of one or two minutes observe the diminu- 
tion which has taken place. Wash an equal quantity with 
caustic potash ; note the loss ; and submit the residue to the 
action of oxy-muriatic acid as before. The second diminu- 
tion, thus effected by oxy muriatic gas, divided by 2.2, gives the 
proportion of olefiant gas. Deduct this absorption from the 
first, and, dividing the remainder by 1.8, we obtain the quan- 
tity of sulphureted hydrogen. Lastly, to know the quantity 
of carbonic acid gas, substract, from the diminution effected 
by potash, the amount of the sulphureted hydrogen gas. An 
example, taken from actual experiment, will best explain the 
application of this rule. 
One hundred measures of the first product of gas from 
cannel coal lost, by agitation with liquid potash, 9.7 measures. 
