Royal Society of Edinburgh. 457 
ROYAL SOCIETY OF EDINBURGH. . 
Monday, 15th December, a paper was read before the Royal 
Society of Edinburgh, which had been announced at ‘the first 
meeting in November, by Dr. Marray, containing Experiments 
on Muriatic Acid. He had repeated the experiment performed 
by Dr. Ure, of subliming muriate of ammonia over ignited me- 
tals, with the variation of operating on the salt for med by the 
combination of muriatic acid aud ammoniacal gases, instead of 
the common sal ammoniac, which from its mode of preparation 
might be supposed to contain water. He obtained a similar re- 
sult, water appearing when the muriate of ammonia was sublimed 
over iron at a red heat in a glass tube. His attention having 
been thus recalled to the subject, he repeated the experiment 
which he had performed some years ago, of obtaining water from 
muriate of ammonia by heat, employing an apparatus somewhat 
on the principle of Dr. Wollaston’s Cryophorus, and with a sue- 
cessful result. He then submitted muriatic acid gas to experi- 
ment in various modes, Iron filings perfectly dry and clean 
having been put into a glass tube, “surrounded with sand, and 
placed across a furnace, so as to be raised to a red heat, muri- 
atic acid gas extricated from a mixture of supersulphate of potash 
and muriate of soda, and conveyed through a tube containing 
dry muriate of lime adapted to the other, was transmitted over 
the ignited iron, Moisture immediately appeared in the tube 
beyond the ignited space, and soon collected in globules, and 
hydrogen gas was disengaged. In another experiment the gas was 
previously kept in contact with muriate of lime for a number of 
hours, and was then passed from the jar over the ignited metal 
with a similar result. Aud in another form of apparatus, still 
better adapted to afford a perfect result, and to obviate any fal- 
lacy from the presence of aqueous vapour, muriatic acid gas 
was conveyed, from a jar in which it had been exposed to dry 
muriate of lime, through a bent tube, into a tubulated retort con- 
taining dry zine filings; heat was applied by alamp to favour 
the action of the metal on the gas: moisture condensed in the 
curvature and tube of the retort, and hydrogen gas was collected 
at the extremity, which terminated under mercury. ‘The heat 
was renewed at intervals for three or four days, with the requisite 
addition of fresh quantities of the muriatic acid gas, and the 
production of moisture increased, until a very sensible quantity 
of water was obtained at the end of the experiment. The pro- 
secution of the subject is announced in a continuation of the 
paper to be read at a future meeting of the Society. 
LXXVIIT. In- 
