43 6 Dr. Henry's Experiments on Ammonia , &c. 
most obvious one, was its decomposition by oxymuriatic acid 
gas ; but this plan was abandoned, from the impossibility of 
confining both the gases by any one fluid ; since water acts 
powerfully on the one, and mercury on the other. But a mix- 
ture of oxygen and ammoniacal gases more than answered 
my expectations. When mingled in proper proportions, these 
gases, I have ascertained, may be detonated over mercury 
by an electric spark ; exactly like a mixture of vital and in- 
flammable air; and the results of the process, with due atten- 
tion to the circumstances, which will soon be stated, afford an 
easy and precise method of analyzing, in the space of a few 
minutes, considerable quantities of the volatile alkali. With 
a greater proportion of pure oxygen gas* to ammonia than 
that of three to one, or of ammonia to oxygen than that of 
three to 1.4, the mixture ceases to be combustible. When the 
proportions best adapted to inflammation are used, oxygen 
gas may be diluted with six times its bulk of atmospherical 
air, without losing its property of burning ammonia. 
Atmospherical air alone does not, however, inflame with 
ammonia, in any proportion that I have yet tried; though, by 
long continued electrization with air, ammonia is at length 
decomposed ; its hydrogen uniting with the oxygen of the air 
and forming water, while the nitrogen of both composes a 
permanent residuum. Forty-five measures of ammonia being 
electrified with eighty-six of common air, the total 131 be- 
came 136, and 132 after being washed with water. Of 17.2 
measures of oxygen, contained in the 86 measures of air at 
the outset, only 2.9 were left, and these, also, would proba- 
bly have disappeared by continuing the operation. If a mix- 
* Containing only three or four per cent, nitrogen gas. 
