QUALITIES. _Colour_, pale yellow; _Odour_, fragrant and pungent, having
the characteristic smell of prussic acid. _Taste_, pungent, bitter, and
peculiar. SOLUBILITY. Like other essential oils, its sensible properties
and medicinal effects are imparted to water; in alcohol it is very
soluble.[580] CHEMICAL COMPOSITION. A peculiar oil, combined with
hydro-cyanic acid. M. Vogel of Munich has lately succeeded in separating
these constituents, by agitating the whole in a concentrated solution of
potass, and distilling to dryness; the oil volatilized together with
water, while the residuum in the retort was found to contain _Cyanide of
Potassium_. The volatile oil, thus purified, is without odour, and
heavier than water. Its taste is extremely acrid and burning; by contact
with air it crystallizes rapidly; it dissolves easily in alcohol and
æther, but only in a very small proportion in water. The flame of its
combustion is very brilliant, and accompanied with much smoke. In order
to discover whether this oil, when freed from its hydro-cyanic acid, is
still poisonous, M. Vogel put a drop of it on the tongue of a sparrow;
when it died, after violent convulsions, in a few seconds; he also
poisoned a dog, two months old, with four drops of it; whence he
concludes that the volatile oil, divested of its hydro-cyanic acid, is
still a poison, although less energetic than the oil that has not
undergone such a change. _Med: Uses._ It has all the characteristic
effects of prussic acid, but is so powerful and dangerous as to preclude
its application. It is principally sold to perfumers and confectioners.
It is generally obtained by distilling the expressed cake of bitter
almonds; the operation however requires considerable pharmaceutical
address, and is, moreover, attended with unpleasant consequences.[581]