gaseous mixtures , and its application to their analysis. 279 
3rdly. Carburetted hydrogen, exposed under the same 
circumstances, was not in the least acted upon by a tempera- 
ture of 555 0 Fahrenheit, the highest of which, by an Ar- 
gand’s lamp, I was able to raise the mercurial bath. This, 
however, must have been near the temperature required for 
combination ; for on removing the retort from the mercurial 
bath, and applying a spirit lamp, at such a distance as not to 
make the retort red hot, a diminution of volume commenced, 
and continued till all the carburetted hydrogen was silently 
converted into water and carbonic acid. 
4thly. Cyanogen, similarly treated, was not changed at a 
temperature of 555 0 Fahrenheit, and on applying the flame 
of a spirit lamp to the tube, it produced no action till the tube 
began to soften. 
5thly. Muriatic acid gas, mixed with half its volume of 
oxygen, began to be acted upon at 250° Fahrenheit. Water 
was evidently formed ; and the disengaged chlorine, acting 
upon the mercurial vapour in the tube, formed calomel, which 
was condensed, and coated its inner surface. 
6thly. Ammonical gas, mixed with an equal volume of 
oxygen, showed a commencement of decomposition at 380° 
Fahrenheit. Water was also in this case distinctly gene- 
rated ; and at the close of the experiment, nothing remained 
in the tube but nitrogen and the redundant oxygen. 
I proceeded, in the next place, to examine the agency of 
finely divided platinum at high temperatures, on those mix- 
tures of gases, which are either not decomposed, or are 
slowly decomposed, at the temperature of the atmosphere. 
When carbonic oxide and hydrogen gases, in equal vo- 
lumes, mixed with oxygen sufficient to saturate only one of 
