296 EXPERIMENTS AND OBSERVATIONS © 
of the-metal decomposing the acid, attracting its chlorine and 
liberating its hydrogen. And the experiment is farther free 
from the only resource which remained to the advocates of 
that doctrine, in the case of water being obtained from mu- 
riate of ammonia, that it might be derived from the decompo- 
sition of the elements of ammonia, regerding it as an alkali 
containing oxygen. If water were really obtained from the 
combination of muriatic acid and ammoniacal gases, it would 
rather indicate, it was said, the decomposition of nitrogen 
than the existence of water as a constituent of muriatic acid. 
No weight, I believe, is due to such an assumption, but if any 
importance were attached to it, it is precluded if water is ob- _ 
tained from the action of metals on muriatic acid gas. 
I have executed the experiment in several forms; and in all 
with a more or less satisfactory result. 
One hundred grains of iron filings, clean and dry, were 
strewed for a length of five or six inches, in a glass-tube which 
was placed in an iron case, across a small furnace, so as to ad- 
mit of being raised to a red heat. This tube, of about two 
feet in length, was connected with a wide tube eight inches 
Jong, containing dry and warm muriate of lime; and this was 
farther connected, at its other extremity, with a retort afford- 
ing muriatic acid gas, from a mixture of super-sulphate of pot- 
ash and muriate of soda. The open extremity of the long 
tube, dipped by a slight curvature in quicksilyer. On the iron 
being raised to ignition, and the transmission of the acid gas 
being conducted slowly, elastic fluid escaped from the extre- 
mity of the tube, which was found to be hydrogen, and though 
no trace of moisture appeared in the anterior part of the tube, 
it immediately condensed in that part which was cold, beyond 
the iron filings. This accumulated in globules, and at length 
run 
