x r ^ Dr. Austin’s Experiments on 
that an accurate analyfis of the heavy inflammable air can 
never be obtained in this manner. 
I therefore attempted to decompofe the heavy inflammable 
air by means of fulphur, which readily unites with the light 
inflammable air in a condenfed ftate, and with it forms hepatic 
air. Having introduced fome fulphur into a retort, filled with 
heavy inflammable air, and applied a lufficient heat to melt 
and lublime it, I found, that a confiderable quantity of hepatic 
air was formed. After this air was abforbed by water, I could 
not perceive that the remaining air differed from the heavy 
inflammable air before the operation. Sulphur mixed with 
powdered charcoal, upon being heated, yields hepatic air in 
great abundance, almoft the whole of which is ablorbed by 
water. The fmall unabforbed refidue, which does not exceed 
a hundredth part of the bulk of the whole air, appears to be 
phlogifticated air. 
In whatever manner the heavy inflammable air was decom- 
pofed, whether by palling the electrical fpark through it, by 
melting fulphur in it, or by heating fulphur and charcoal toge- 
ther, an appearance conftantly occurred, which feemed to indi- 
cate, that volatile alkali is formed, whenever the heavy inflamma- 
ble air is decompofed. The circumftance is this : a fmall piece 
of paper, flained with any blue vegetable fubftance, is turned 
green byftanding in the air during any of thefe procefies ; and 
this green is changed to red upon the addition of an acid. The 
inflammable air had been very long expofed to water, and had no 
fuch effeCt upon blue vegetable fubftances before the operation. 
I have concluded thefe analytic attempts with feveral 
obfervations on the formation of fixed air from fome fubftances, 
which confift only of the light inflammable, phlogifticated, 
and dephlogifticated airs, and from others, in which thefe three 
airs 
