_Solution of Ammonia._
QUALITIES. _Form_, a limpid, colourless fluid; _specific gravity_, ·960,
or f℥j weighs about 438 grs. _Odour_, strong and pungent; _Taste_,
extremely caustic. CHEMICAL COMPOSITION. A solution of ammoniacal gas in
water, which varies considerably in strength in the different
pharmacopœias. When prepared according to the London and Edinburgh
Colleges, it contains nearly 25 per cent. of ammonia, whereas the Dublin
preparation does not contain more than 16. SOLVENT POWERS. It is an
active solvent of many vegetable principles, e. g. _oils_, _resins_, &c.
With alcohol it unites in every proportion; it assists the oxidizement
of copper and zinc, and dissolves many of the metallic oxides. MED.
USES. Stimulant, rubefacient, and antacid. FORMS OF EXHIBITION. In milk,
or any liquid vehicle; if in decoctions, or infusions, they must be
previously cooled; for at 130° the ammonia will escape in the form of
gas. DOSE, ♏︎x to xxx. OFFICINAL PREP. _Linimentum Ammoniæ._ L.D. _Oleum
Ammon._ E. _Spir. Ammoniæ_. L. _Spir. Ammoniæ comp._ L. _Spir. Ammon.
succinat._ L. _Liniment. Camphor. comp._ L. ADULTERATIONS. The presence
of other salts in the solution may be discovered by saturating a portion
with pure nitric acid, and applying the test for sulphuric acid,
(_Barytes_) and that for muriatic acid, (_Nitrate of Silver._) Carbonic
acid is detected by its effervescing with acids, or by its forming with
lime water, a precipitate, soluble with effervescence in nitric acid; it
ought to be free from all fetor; its strength can only be determined by
taking its specific gravity. It should be preserved in well closed
bottles, and their dimensions should be small, for when in large vessels
it often becomes carbonated before it is half used.