(Cynips Quercus folli _Nidus_.) _Gall Nuts._
QUALITIES. _Form_, excrescences, nearly round and of different
magnitudes, smooth on the surface, but studded with tuberosities; they
are heavy, brittle, and break with a flinty fracture. _Odour_, none;
_Taste_, bitter and very astringent. SOLUBILITY. The whole of their
soluble matter is taken up by forty times their weight of boiling water.
Alcohol, by digestion, dissolves .7, and æther .5 of their substance.
The watery infusion possesses all the properties of the gall-nut, and
reddens vegetable blues. CHEMICAL COMPOSITION. Is at present involved in
some obscurity; it contains tannin, gallic acid, a concrete volatile
oil, and perhaps extractive and gum. M. Braconnot has also lately
discovered in the gall-nut a new acid, which he calls _Ellagic acid_,
from the word _galle_ reversed, a nomenclature which it must be
confessed is at least free from the objections urged against that which
is founded upon chemical composition. (_See Annales de Chimie, vol. ix.
p. 187, new series_; also _Children’s Essay on Chemical Analysis, p.
276_.) INCOMPATIBLE SUBSTANCES. The infusion and tincture of galls
possess habitudes with which it is very important for the medical
practitioner to be acquainted, not only for the purpose of directing
their exhibition with success, but because the elements which impart to
them their characteristic traits, viz. _Gallic Acid_ and _Tannin_,[512]
are very widely diffused through the products of the vegetable kingdom,
and will be found to be constantly active in their chemical, medicinal,
and pharmaceutical relations. Metallic salts, especially those of iron,
produce precipitates with infusion of galls, composed of tannin, gallic
acid, and the metallic oxide; of these compounds the _tanno-gallate of
iron_ is the most striking, being of a black colour; those of
_sub-acetate_ and _acetate of lead_ are greyish; _tartarized antimony_
produces a yellowish; _sulphate of copper_ a brown; _sulphate of zinc_
reddish black; _nitrate of silver_, a deep olive; and _nitrate of
mercury_, a bright yellow precipitate; the _oxy-muriate of mercury_
produces only an opacity. _Sulphuric acid_ throws down a yellowish curdy
precipitate, _muriatic_, a flaky and white one, and _nitric acid_ merely
modifies the colour of the infusion, although it destroys its
astringency; the solution of _ammonia_ occasions no precipitate but
renders the colour deeper, the _carbonate_ however throws down a
precipitate; the carbonates of the _fixed alkalies_ produce a yellowish
flaky, and _lime water_ a copious green precipitate. The _tannin_ in the
infusion of galls is precipitated by a solution of isinglass or of any
other animal jelly, by that of starch, and by many metallic oxides.
MEDICINAL USES. Galls are most powerfully astringent. The native
practitioners of India not only administer them as astringents in
dysentery, but as tonics in cases of intermittent fever. FORMS OF
EXHIBITION. In that of powder; and in combination with other astringents
(_Form. 51_,) or with aromatics and bitters. As a local remedy the
gall-nut enters into gargles and injections; for _blind_ piles, an
ointment composed of 2½ parts of finely powdered galls, and a small
portion of opium, with three parts of simple ointment as an excipient,
offers a very valuable resource. (_Form. 55._) In some cases of
hemorrhoids, prolapsus ani, and fluor albus, the application may be made
in the form of a fomentation, for which purpose two drachms of bruised
galls should be macerated for an hour in a pint of boiling water, which,
when cold, may be used in the usual manner. DOSE, for internal
exhibition, grs. x–℈ij, or more. OFFICINAL PREP. _Tinct. Gallarum_. E.D.
OBSERVATION. Those which are small, protuberant, bluish, and heavy, are
the best, being such as have been collected before the _larvæ_ within
them had changed to the state of fly, and eaten their way out; a white,
or a red hue indicates an inferior quality, and are those from which the
insect has escaped. Aleppo galls are the most valuable, as being the
most astringent.