Solution of Acetate of Ammonia.
olim, _Spirit of Mindererus_.
This preparation is a solution of the neutral _acetate of ammonia_, with
a proportion of carbonic acid diffused through it; it is made by
saturating the sub-carbonate of ammonia with distilled vinegar, for
which purpose it will generally be found that ℥j of the alkali will
saturate oiss of the vinegar; since, however, the quantity of acid in
distilled vinegar as well the strength of the ammonia, are liable to
constant variation, the exact point of neutralization should be
ascertained by the alternate application of litmus and turmeric papers;
for if the proportions be not accurately adjusted, some of the metallic
salts, especially those of _antimony_, which are often prescribed in
conjunction with it, are decomposed, and thus rendered inefficacious;
and on this account an excess of alkali is to be feared more than that
of acid. This preparation is also not unfrequently employed as a
collyrium, when much serious mischief may arise from the carbonate of
ammonia predominating. It has been already stated that a very minute
proportion of extractive matter is rendered sensible on the addition of
an alkali; hence this preparation frequently derives from the vinegar a
brown hue, which may be removed by filtering the solution through a
little well burnt charcoal. It also deserves notice that the presence of
a trace of copper, derived from the copper cocks through which the
vinegar has passed, will impart a _brown_ tinge, whilst in larger
quantities this metal yields a _blue_ colour with ammonia. INCOMPATIBLE
SUBSTANCES. _Acids_; _fixed alkalies_; _alum_; _lime water_; _sulphate
of magnesia_; _corrosive sublimate_; _nitrate of silver_; and the
_sulphates of zinc, copper, and iron_. _Acetate of lead_ produces also a
copious precipitation, but this depends upon the presence of the
carbonic acid diffused through the solution, which decomposes the salt
and forms an insoluble carbonate of lead. _Magnesia_ likewise, contrary
to what might be supposed, decomposes the solution and renders it
pungent, from the extrication of ammoniacal gas; this phenomenon depends
upon the magnesia forming a triple acetate with one part of the ammonia,
and setting the remainder at liberty. MED. USES. When assisted by warmth
and plentiful dilution, it is an excellent diaphoretic, and produces its
effects without quickening the circulation: (_Form: 117, 126_,) by
keeping the surface of the body cool, its action is determined to the
kidneys, and it proves diuretic, especially when combined with remedies
of a similar tendency. (_Form: 111._) DOSE, fʒiv to fʒxij. Externally it
furnishes a lotion, valuable as a refrigerant, especially when combined
with some spirituous preparation. See _Form: 148_.