gaseous mixtures , and its application to their analysis. 283 
From the foregoing Table it appears, that carbonic oxide 
produces the greatest effect, in the smallest proportion to an 
explosive mixture of oxygen and hydrogen, in ^preventing 
the action of those gases on each other, when exposed to the 
sponge at temperatures below the boiling point of mercury. 
In general, those gases which either do not unite with oxy- 
gen, or unite with it only at high temperatures, have little 
effect in restraining the efficiency of the sponge. There is 
an apparent exception, however, in cyanogen, which it would 
require more research than I have yet had time to devote to an 
object merely collateral to reconcile it, if it be capable of being 
reconciled, with the general principle. 
From the fact that carbonic oxide, olefiant gas, and car- 
buretted hydrogen, when brought to unite with oxygen by 
means of the platinum sponge assisted by heat, undergo this 
change at different temperatures, it seemed an obvious con- 
clusion, that by exposing a mixture of those gases with each 
other and with oxygen to a regulated temperature, the cor- 
rect analysis of such mixtures might probably be accom- 
plished. Mixtures of two or more of the combustible gases 
were therefore exposed, in contact with oxygen gas and the 
platinum sponge, in tubes bent into the shape of retorts, 
which were immersed in a mercurial bath. This bath was 
gradually heated to the required temperatures, and by proper 
management of the source of heat, was prevented from rising- 
above that degree. 
1st. By subjecting 25 measures of carbonic oxide, 15 of 
olefiant gas, and 57 of oxygen, in contact with the sponge, 
to a heat which was not allowed to exceed 350° Fahrenheit 
till the diminution of volume ceased, all the carbonic oxide 
