(Arboris nondum descriptæ, _Gummi-resina_.)
_Myrrh._
QUALITIES. _Form_, irregularly shaped pieces, translucent, of a reddish
yellow colour; _Odour_, peculiar and fragrant; _Taste_, bitter and
aromatic. CHEMICAL COMPOSITION. Resin, gum, essential oil, and some
extractive. SOLUBILITY. When triturated with soft, or distilled water,
nearly the whole appears to be dissolved, forming an opaque, yellowish
solution, but by rest the greater part is deposited, and not more than
one-third is actually dissolved; its solubility, however, in water may
be increased by trituration with camphor or an alkali; rectified spirit
dissolves it, and the resulting tincture, when diluted, becomes turbid,
although no precipitate occurs. MED. USES. Stimulant, as in _Form. 103_.
Expectorant, 132, 133, 138. Emmenagogue, 95, 98, 99. It is also tonic,
and agrees with some constitutions better than any of the bitters. FORMS
OF EXHIBITION. No form is so eligible as that of substance. DOSE, grs. x
to ʒj. The alkalies, in their crystalline state, when triturated with
myrrh, reduce it to the form of a tenacious fluid. OFFICINAL
PREPARATIONS. _Tinct. Myrrh_. L.E.D. _Tinct. Aloes et Myrrh_. E. _Tinct.
Aloës Ætherea_. E. _Mist. Ferri comp_. L. (=G L=) _Pil. Aloes cum
Myrrha_. L.E.D. _Pil. Ferri cum Myrrha_. L. _Pil. Galb. comp_. L.D.
(=B=) _Pil. Assafœtid. comp_. E. (=B=) _Pil. Rhei, comp_. E. (=G=)
ADULTERATIONS. It is subject to a variety of frauds, being frequently
mixed with adventitious gums, which are to be detected by their foreign
odour, their white or dark colour, and by their opacity.