27° Dr . Henry on the action of finely divided platinum on 
about one-fourth of the olefiant gas was consumed ; and by 
increasing the proportion of the explosive mixture, the olefiant 
gas was still more acted upon. On using oxygen sufficient 
to saturate both the hydrogen and the olefiant gases, the ball 
acted much more rapidly ; in several instances it became red 
hot ; all the hydrogen was consumed ; and the whole of the 
olefiant gas was changed into water and carbonic acid. In 
this case the use of the sponge is inadmissible, as it kindles 
the gases, and occasions their detonation. 
II. Mixtures of Hydrogen and Carhuretted Hydrogen Gases with 
Oxygen. 
When carburetted hydrogen, procured from stagnant water 3 
was added to an explosive mixture, in various proportions be- 
tween equal volumes, and ten of the former to one of the latter, 
the action of the hydrogen and oxygen on each other took 
place as usual, on admitting one of the balls. When, revers- 
ing the proportion, the explosive mixture was made to exceed 
the carburetted hydrogen, but not more than four or five 
times, the latter gas was entirely unchanged. With a larger 
proportion of the explosive mixture carbonic acid was always 
found to have been produced ; but still the carburetted hy- 
drogen was very imperfectly consumed, and fully three- 
fourths of it were generally found to have escaped unburned. 
When, to a mixture of hydrogen and carburetted hydro- 
gen, oxygen enough was added to saturate both gases, the 
effect of the sponge was found to vary with the proportion, 
of the simple hydrogen. In several cases, where the hydro- 
gen did not exceed the carburetted hydrogen more than 
four times, the latter gas remained unchanged ; when in 
