34 Dr. Murray’s Experiments on (Jan. 
retort, as far as could be done, without raising dense vapours. 
Globules of liquid, perfectly limpid, collected pretty copiously 
towards the middle and lower part of the neck, and the receiver, 
on being removed from the freezing mixture, was covered inter- 
nally with a film of moisture. The globules in the neck of the 
retort were absorbed by a slip of bibulous paper, and the quantity 
was found to amount to 1-2 gr, The receiver being dried care- 
fully and weighed, lost by the dissipation of the moisture within 
0-4 gr. Distilled water, in which the bibulous paper was 
immersed, was quite acid ; it gave no sensible turbidness on the 
addition of ammonia, or of carbonate of soda, and held dissolved, 
therefore, merely pure muriatic acid. The mass in the retort 
was of a grey colour, with metallic lustre, in loosely aggregated 
laminee somewhat flexible. It weighed 114:8 gr. Adding to this 
increase of weight which the zinc had gained the weight of the 
water and the hydrogen gas expelled, it gives a consumption of 
muriatic acid gas of about 16:8 gr. equivalent to about 43 cubic 
inches. Supposing the weight of water to be doubled, or nearly 
80, by saturation with muriatic acid, this gives the product of 
water in the experiment as equal to nearly one gr.; or about 
ith of the whole quantity of combined water which muriatic acid 
gas is calculated to contain.* 
Tn all the preceding experiments, water has been procured 
from muriatic acid gas. It is obvious that such a result cannot 
be accounted for on the hypothesis that it is the real acid free 
from water, a compound merely of chlorine and hydrogen. On 
the opposite doctrine, as muriatic acid in its gaseous form is held 
to contain water, it may be supposed to afford a portion of it. 
It may be maintained, however, in this, as it was in the expe- 
rment of obtaining water from the muriate of ammonia by heat, 
that the water produced is derived from hygrometric vapour in 
the gas. To obviate this, it is sufficient to recur to the fact 
established by the experiments of Henry and Gay-Lussac, that 
muriatic acid gas contains no hygrometric vapour; and to the 
% The action of the metals on the muriatic acid gas taking place in the above 
experiments at a heat comparatively mcderate, it occurred tu me that they might 
exert a similar action with no higher heat on the acid in muriate of ammonia, and 
that this might afford an easy mode of exhibiting tie results. I accordingly found, 
that on mixing different metals with sal ammoniac in powder, previously exposed 
to asubliming heat, and exposing the mixture to heat by a lamp, so regulated as to 
be short of volatilization, the salt was decomposed, ammoniacal gas was expelled, 
and moisture condensed io the neck of the retort, covering a space of several 
inches with small globules, and at length running dcwn. The metals [ employed 
were iron, zinc, tin, and lead ; 100, 150, or 200 gr. af cach metal, dry and warm, 
being mixed with 100 gr. of the salt likewise newly heated. To obviate any fal- 
lacy from common sal ammoniac being employed, { repeated the experiment with. 
the salt formed from the combination of its two coustituent gases, and ohtained the 
same result, But although this affords an easy mode of exhibiting the production 
of water, it is not favourable to obtaining a perfect result, the heated ammoniacal 
gas carrying off a considerable portion of the water deposited ; and accordingly 
the quantity, instead of increasing as the experiment proceeds, at length diminishes, 
and the ammoniacal gas deposits a portion ef water in passing through mercury, or 
in. being conveyed through a cold tube. 
