QUALITIES. This wood is heavier than water, and emits when heated an
aromatic odour; _Taste_, bitterish and sub-acrid; to extract its virtues
long decoction is required. It has enjoyed great reputation as a
specific in the venereal disease; it was imported into Europe in 1517,
and gained immediate celebrity from curing the celebrated Van Hutten:
long before this period, however, it was used by the natives of St.
Domingo. Boerhaave, so late as the eighteenth century, maintained its
specific powers. It seems probable that the discipline which always
accompanied its exhibition, such as sweating, abstinence, and purgation,
might be the means, in the warmer climates, of effecting cures which
were attributed to the guaiacum. OFFICINAL PREPARATIONS. _Decoct:
Guaiaci comp:_ E. _Decoct: Sarsaparill: comp:_ L.D.
B. THE GUAIAC, or _Resin_.
QUALITIES. _Form_; it has the aspect of a gum resin; _Colour_, greenish
brown; it is easily pulverized, and the powder, which is at first grey,
becomes green on exposure to air and light, which appears to depend upon
the absorption of oxygen: when heated, it loses its colour; it melts by
heat; and has a _sp. grav:_ of 1·2289. SOLUBILITY. _Water_ dissolves out
of it about 9 per cent. of extractive matter; _alcohol_ 95, and _æther_
40 parts in a hundred. The _alkaline_ solutions and their _carbonates_
dissolve it readily; _Sulphuric acid_ dissolves it with scarcely any
effervescence, and affords a solution of a rich claret colour; _Nitric
acid_ dissolves it with a copious extrication of nitrous fumes;
_Muriatic acid_ dissolves a small portion only; but in all these cases
the guaiacum is decomposed; the acids are therefore incompatible with
it. CHEMICAL COMPOSITION. The experiments of Mr. Hatchett demonstrate
that it is a substance _sui generis_, and not a resin, or gum-resin.
MED. USES. Stimulant, diaphoretic,[517] and in large doses, purgative.
FORMS OF EXHIBITION. In that of bolus; or diffused in water, by means of
one half of its own weight of gum arabic. DOSE, gr. x. to ʒss. OFFICINAL
PREP: _Mist: Guaiac:_ L. _Tinct. Guaiac._ L.E.D. _Tinct. Guaiac.
Ammoniat._ L.E.D. _Pulv. Aloes com._ L.D. (=O.M.=) ADULTERATIONS.
_Common resin_ may be detected by the turpentine emitted when the guaiac
is thrown upon hot coals; _Manchinal gum_, by adding to the tincture a
few drops of sweet spirit of nitre, and diluting with water; the guaiac
is thus precipitated, but the adulteration floats in white striæ.