y 
4 
z 
, 
4 
b 
i 
4 
ON MURIATIC ACID Gas, &c. 307 
in the experiment of heating the muriate of ammonia with the 
different metals, afforded similar indications of acidity. 
These results appear to establish the production of a super- 
muriate in the action of these metals on the acid, and this ac- 
counts for the appearance of a portion of water, since, suppo- 
sing water to exist in muriatic acid gas, the quantity combined 
with that proportion of acid which would establish a neutral 
compound, is the quantity required to oxidate the metal to 
form that compound ; and if any additional portion of acid en- 
ter into union, the water of this must be liberated, or be at 
least capable of being expelled. 
It was of importance, in relation to this question, to ascer= 
tain the quantity of hydrogen obtained from a given quantity. 
of muriatic acid gas; for, if the whole water essential to the 
acid is decomposed by the action of the metal, half the volume 
of hydrogen ought to be obtained,—muriatic acid gas being 
composed of equal volumes of oxymuriatic gas and hydrogen 
gas. I made this repeatedly the subject of experiment, by heat- 
ing zinc and iron in muriatic acid gas. There are difficulties. 
in determining the proportion with perfect precision; but the 
quantity of hydrogen always appeared to be less than the half; 
and on an average, about twelve measures were obtained, when 
thirty measures of the other had been consumed, a result con- 
formable to the liberation of a portion of the combined water 
of the gas. 
Whether the production of water in these experiments is sa- 
tisfactorily accounted for, on the cause now assigned, may be 
subject of farther investigation. In the sequel, I shall have to: 
notice another principle, on which perhaps it may fall to be 
explained. Whether accounted for or not, it is obvious, that 
the fact itself is not invalidated by the theoretical difficulty ; 
and also, that in relation to the argument with regard to the na- 
Qq2 ture 
