carbonated hydrogenous Gas. 411 
have been exhibited under the form of a neutral salt. When 
water was passed up to this mixture of the two gases, there 
was an absorption not only of the muriatic gas, but of some- 
thing more. 
Conceiving that the demolition of charcoal, by the action 
of the electric fluid, was sufficiently proved by his experi- 
ments, Dr. Austin assigns the evolved hydrogen as one of its 
constituents, and the other he concludes to be azote. This 
inference, however, rests almost entirely upon estimates, in 
which material errors may be discovered. Some of these it 
may be well to point out, for the satisfaction of such as have 
acquiesced in Dr. Austin's opinion. 
The carbonated hydrogenous gas submitted to Dr. Austin’s 
experiments clearly appears, from his own account, to have 
been largely adulterated with azotic gas. One source of its 
impurity he has disclosed, by informing us that the gas “ had 
“been very long exposed to water;”* for Dr. Higgins has 
somewhere shewn that the heavy inflammable air, after stand- 
ing long over water, leaves a larger residue of azote, on com- 
bustion, than when recently prepared.^ It is probable also, 
that the proportion of azote derived from the water, would in- 
crease with the time of its exposure ; and thus a fertile source 
of error is suggested, which appears wholly to have escaped 
Dr. Austin's attention. In repeating his experiments, I was 
careful that comparative ones, on two equal quantities of the 
* 80 Phil. Trans. 54. ' 
f Similar facts respecting the deterioration of other gases, by standing over water, 
may be seen in Dr. Priestley’s Experiments on Air, Vol. I. p. 59, 158. I found 
that oxygenous gas, from oxygenated muriate of pot-ash, acquired, by exposure a few 
weeks to water, .125 its bulk of azotic gas. 
MDCCXCVII. 3 H 
