These may contain, with the exception of gum, all the ingredients
contained in watery extracts, besides resin; their composition however
will greatly depend upon the strength of the spirit employed as the
solvent; but of this I shall speak more fully under the article
_Tincture_.
EXTRACTUM CINCHONÆ RESINOSUM. L.E.D. The operation of spirit in this
preparation is two-fold; it extracts from the bark the element which is
insoluble in water, and it diminishes the tendency in the extractive
matter to absorb oxygen during the process. _Dose_, grs. x to xxx. It is
said that a spurious extract of bark is to be met with in the market,
consisting of the extract of the horse-chesnut tree bark, and yellow
resin.
EXTRACTUM COLOCYNTHIDIS COMPOSITUM. L.D. _Extract. Catharticum._ P.L.
1775. _Pilulæ Rudii._ P.L. 1720. This preparation has been established
through successive pharmacopœias, and has undergone some modification in
each; in the present edition the soap has been restored, and its
solubility is thereby increased, as well as its mildness as a cathartic.
The omission of this ingredient was formerly suggested by the
consideration of its being incompatible with _Calomel_; this however is
_not_ the case. It presents a combination of purgative substances which
is highly judicious, and will be found to be more powerful than an
equivalent dose of any _one_ of the ingredients. _Dose_, gr. v to ʒss,
_Form. 71, 81, 88._
EXTRACTUM JALAPÆ. L.E.D. It is purgative, but is liable to gripe, unless
it be triturated with sugar and almonds, or mucilage, so as to form an
emulsion. _Dose_, grs. x to ℈j.
EXTRACTUM RHEI. L. The powers of the Rhubarb are considerably impaired
in this extract. _Dose_, grs. x to ʒss. _Form. 78._