112 Experiments on Muriatie Acid Gas. 
densed by water; the residue burned with the flame of hydro- 
en. The tube, for several inches, was studded with globules 
of water, and was bedimmed with vapour further. I did not 
prosecute the experiment, so as to ascertain the weight of water 
reduced, as I had other experiments in view, which I conceived 
might afford more conclusive results. But it proves the point it 
was designed to establish, that water is obtained from the salt 
formed by the combination of the gases, as weil as from the 
common sal ammomiac. , 
My attention having been thus recalled to the subject, I have 
again executed the experiment in its original and simplest form, 
—that of obtaining water from the salt by heat alone; and to 
this Iwas led more particularly, as it had occurred to me, that 
a more perfect abstraction of its water might be effected, by 
conducting the experiment in an apparatus somewhat on the 
principle of the instrument invented by Dr. Wollaston, which he 
named the Cryophorus. In a retort of the capacity of seven 
cubic inches, fitted with a stop-cock, and exhausted, sixty cubic 
inches of ammoniacal gas were combined with the requisite 
quantity of muriatic acid gas, each previously carefully dried,— 
the former by exposure to potash, the latter by exposure to 
muriate of lime. The stop-cock was then detached from the 
retort; the excess of ammoniacal gas was removed by a caout- 
chouc bottle, and replaced by atinospheric air; the salt was 
pushed down from the neck ; and it was eonieeted with another 
similar retort, the joing of the two being secured by cement. 
This last retort was also fitted with a stop-cock adapted to a 
tubulature at its curvature; and heat being applied to it, a little 
of the included air was allowed to escape. It was then placed in 
a mixture of muriate of lime and ice, while the other, contain- 
ing the muriate of ammonia, was placed in warm oil. .The heat 
of this was raised to 420° of Fahrenheit: moisture condensed 
at the upper part of the neck, when the heat had been raised to 
220°, and continued for some time to increase. It then dimi- 
nished, from the continued application of the heat, carrying it 
forward into the cold retort; and at the end of the experiment a’ 
considerable part of the body of this was encrusted with a thin 
film-of ices This result, therefore, coincides entirely with what 
had been before obtained *. 
* The other papers in this controversy by Dr. Ure and Dr. Murray, will 
be given in a subsequent number. 
XVIII. On 
