Acidum Gallicum

Gallic Acid

Acide gallique, Fr.; Gallậpfel-saure, Ger.

Gallic acid is in small, silky, nearly colorless crystals, having a slightly acid and astringent taste. It is soluble in one hundred parts of cold and in three of boiling water. The solution reddens litmus, and does not produce a precipitate with a solution of gelatin, or of sulphate of protoxide of iron. With solutions of salts of sesquioxide of iron it produces a bluish-black precipitate, the color of which disappears when the liquid is heated. It is decomposed by a strong heat, and entirely dissipated when thrown on red-hot iron. Dose, gr. j—gr. x.

Unguentum Acidi Gallici

Ointment of gallic acid. (Gallic acid, 10 grm.; benzoinated lard, 90 grm.)

The following remedies contain a tannic acid, and have physiological and therapeutical actions due to the presence of this substance:

Galla

Xutgall. Noix de galle, Fr.; Galläpfel, Ger.

Tinctura Gallae

Tincture of galls. Dose, 3 ss— 3 ij.

Unguentum Gallae

Ointment of galls. (Galls in fine powder, 20 grm.; benzoinated lard, 80 grm.)

Composition

Tannic acid (gallo-tannic), 60 to 70 per cent; gallic acid, 3 per cent; sugar, resin, etc.