New London Pharmacopoeia. 353 
that 100 grains saturate 124 of crystallized subcarbonate of soda, 
which, from some indirect experiments, I believe to be not quite 
correct. _ By the French chemists it is termed hydrochloric acid, to 
express its nature. It acts upon and dissolves several metals with 
the evolution of hydrogen gas arising from the decomposition of water. 
Thus iron, zinc, and tin are readily dissolved by it; it acts but 
slowly upon copper, but dissolves its oxides with facility. Its saline 
compounds are termed muriates, and most of them suffer decompo- 
sition when heated, as I shall explain when describing the properties 
of muriate of lime. side 
“© Composition.—Muriatic acid gas is composed of equal volumes 
of hydrogen gas and chlorine gas; and the combination takes place 
without alteration of volume. By weight it consists nearly of 
Hydrogen 2°7 or 1 atom of hydrogen . 
Chlorine 97°31 do, ofchlorine .. 
100°0. Number representing its atom = 37 
1 
36 
“ Liquid muriatic acid of sp. gr. 1:160 is composed of nearly 
32:4 of muriatic acid gas, and 67°6 water. 
«« Adulteration—This acid, as usually met with, has a yellow 
tinge, which is owing either to the presence of chlorine or of peroxide 
of iron ; if the former be present, it may sometimes be determined by 
the smell, or by its power of dissolving gold leaf; the latter is dee 
tected by the addition of solution of ammonia, which, when added 
slightly in excess, throws down the peroxide of iron of a reddish 
yellow colour. It sometimes also contains sulphuric acid; this is 
discoverable by adding a solution of muriate of barytes to a portion 
of the acid diluted with 4 or 5 parts of distilled water. This dilution 
is requisite, because the acid, when concentrated, attracts the water 
from the solution of muriate of barytes, and causing it to crystallize, 
gives a fallacious appearance of the presence of sulphuric acid. 
** Incompatibles.—This acid is incompatible with alkalies, most 
earths, oxides and their carbonates, sulphuret of potash, tartrate of 
potash, tartarized antimony, tartarized iron, nitrate of silyer, and 
solution of subacetate of lead. 
“* Officinal Preparations. —Ferrum Ammoniatum.—Tinctura Ferri 
muriatis, 
, “ Medicinal usesx—According to Dr. Paris, it may be advanta- 
geously employed in malignant cases of scarlatina and typhus, 
and, mixed witha strong infusion of quassia, he considers it to be the 
most efficacious remedy for preventing the generation of worms. 
Dose m, v.— xx. frequently repeated.” 
When Mr. Phillips says, “ the nature of common salt and the 
production of muriatic acid are explained by two theories,” &c., and 
when he speaks ofthe ‘ supposition that muriatic acid is an unde= 
composed body,” and afterwards, without expressing any doubts 
