Page 243 - My FlipBook

TANNIC ACID. 241

pearance. Tannic acid exists also in rhatany, catechu, and other
vegetable astringents, as it is their chief principle.
Medical Properties and Jction.—Tannic Acid is considered to
be the most active of all vegetable astringents and styptics, and
especially powerful on albumen, gelatin and fibrin. It is very
soluble in water, and less so in alcohol and ether. Taken in-
ternally it produces no nausea, is perfectly safe, and its use may
be continued for a long time without any ill effects. It may
also be administered before and after meals, at all times, and be
combined with many other remedies, such as iron, cod-liver oil,
bitters, etc. Like gallic acid, it is capable of taking oxygen even
from the blood globules, when in contact with alkalies.
It constringes the tissues, temporarily decreasing their vascular-
ity, and causing contraction of their blood vessels. It arrests
secretion and condenses relaxed and feeble tissues. When mixed
with blood, it forms a clot rapidly on account of coagulation of
the albumen.
Tannic acid is converted into gallic acid in the blood, by
absorbing oxvgen from the red corpuscles ; this absorption does
not occur in the stomach.
Tannic acid unites with albumen, fibrin and gelatin, forming
insoluble tannates, thus preserving the parts beneath from the in-
fluence of irritating agents until resolution occurs.
Its solution reddens litmus paper, and it is decomposed and
entirely dissipated when thrown upon red-hot iron.
Listerine is one of the best solvents for tannic acid. One
ounce of listerine will dissolve half an ounce of tannic acid.
Therapeutic Uses.—Internally it is administered in hemorrhages
of the lungs, stomach, kidnevs or uterus, chronic bronchial ca-
tarrh, phthisis, after softening has taken place, intermittent
fever, whooping-cough, chronic diarrhoea, diseases of the genito-
urinary organs, dyspepsia, diphtheria, nervous diseases, etc. Ex-
ternally it is applied to hemorrhages and profuse secretions,
mercurial salivation, diseases of the eye, nasal polypus, gonor-
rhoea and gleet, bed-sores, relaxation of uvula, skin diseases,
ulcers, etc.
Dose.—Of tannic acid, gr. j to 3j, in pill.
16