_Sulphate of Zinc_, olim, _White Vitriol_.
QUALITIES. _Form_, crystals, which are four-sided prisms, terminated by
four-sided pyramids; they are slightly efflorescent; _Taste_, styptic,
metallic, and slightly acidulous. CHEMICAL COMPOSITION. One proportional
of oxide, and one proportional of acid; its crystals contain seven
proportionals of water. SOLUBILITY. It is soluble in 2.5 times its
weight of water at 60°, and in less than its own weight of boiling
water, but is quite insoluble in alcohol. INCOMPATIBLE SUBSTANCES.
_Alkalies_; _earths_; _hydro-sulphurets_; _astringent vegetable
infusions_; _Milk_. MED. USES. Tonic, astringent, and, in large doses
emetic, (_Form. 66._) As an emetic it operates directly, and offers
therefore a prompt resource in cases of poison, or where an immediate
discharge from the stomach is required; it appears to differ from most
remedies of this nature, in not proving diaphoretic in smaller doses: in
spasmodic[720] coughs it is administered with the best effects,
especially when combined with camphor or myrrh, (_Form. 59:_) in
affections of the chest attended with inordinate secretion, I have
witnessed much benefit from its exhibition, particularly when presented
in the form of lozenge; and, when dissolved in water, in the proportion
of grs. ij to f℥j, it forms a useful injection in fluor albus, &c.; in
small doses its internal exhibition is also useful in Leucorrhæa. When
combined with opium it is well calculated to obviate that atony, and
those frequent discharges of fæces, without pain, that take place in the
protracted stages of dysentery. As an external application it is very
generally employed in the proportion of grs. x to eight fluid-ounces of
water. The supposed ill effects consequent on the application of
preparations of lead to a great surface, have determined some
practitioners to substitute in their place, solutions of sulphate of
zinc, but not with the same effect; for to that very property, which may
occasionally render saturnine lotions dangerous, is their virtue to be
attributed; see _Liquor Plumbi Sub-acetatis_. DOSE, as an emetic from
grs. x. to ʒss—as a tonic, and astringent, from grs. j. to ij. OFFICINAL
PREP. _Liquor: Alum: comp:_ L. (=B=) _Solutio Sulphatis Zinci._ _Solutio
Acetatis Zinci._ E. (=I=). _Tinct: Acetatis Zinci_. D. (=I=).
ADULTERATIONS. The _white vitriol_ of commerce ought never to be used in
medicine without previous purification, since it generally contains the
sulphates of copper and iron.
ZINGIBERIS RADIX. L.E.D. (Zingiber Officinale.) _Ginger_.
CHEMICAL COMPOSITION. Volatile oil, fecula, and resino-extractive
matter; on the first of these principles its well known flavour and
odour depend; but its pungency resides in the last. SOLUBILITY. Water,
alcohol, and æther, extract its virtues. MED. USES. It is highly
stimulant and is therefore frequently beneficial in flatulant cholic,
dyspepsia, and gout; it is however more generally employed as an adjunct
to other remedies, to promote their efficacy or to correct their
operation, (see _Form. 92, 94, 112, 153_,) and it is found, that it does
not produce the ill effects of those spices, whose virtues reside in an
acrid oil. DOSE, of the powders grs. x. to ℈j. OFFICINAL PREP. _Syrup:
Zingib:_ L.E.D. _Syrup: Rhamni:_ L. (=E=) _Tinct: Zingib:_ L.D.[721]
_Tinct: Cinnamom: comp:_ L. (=B.=) _Acid_. _Sulphuric: aromat:_ E.
_Confectio Opii_. L. _Confectio Scammon:_ L.D. (=E=) _Infus_. _Sennæ_.
_co._ L. (=E=) _Pulvis Cinnamom: comp:_ L.E.D. (B) _Pulv: Scammon:
comp:_ L.D. (=E=) _Pulv_. _Sennæ_. _comp:_ L. (=E=) _Pil: Aloes:_ D.
_Pill: Scillæ comp:_ L.D. _Vinum Aloes_. L.E.D. ADULTERATIONS. The
powder is rarely met with in any tolerable degree of purity: there are
two varieties of ginger in the market, viz. _Black_, produced by
scalding the root, and afterwards hastily drying it in the sun; and the
_White_, being that which has been carefully washed, scraped, and
gradually dried.