Acidum Tannicum

Gallo-tannic acid—Acidum tannicum (H. S., Br.)—is the best known of the tannins, and is obtained from nut-galls, galla (tf. S., Br.), which are excrescences produced upon oak trees by the puncture of minute insects. It appears as a yellowish, amorphous, odorless, friable mass has an astringent taste very soluble in water, less so in alcohol, almost insoluble in ether its solutions are acid in reaction, and on contact with animal tissues give up the dissolved tannin, which becomes fixed by the tissue to form a tough, insoluble, and non-putrescible material (leather). 

The official definition of tannin (acidum tannicum) given by the Enological Codex is as follows ... 

Actions and Uses.—Internally and extemaUy —Astringent and styptic. Employed in same cases as Acidum Tannicum. 

Preparationa.—Acidnm G-allicum Acidum Tannicum Tinctura Gbllm Unguentum Gallm Unguentum Gallm cum Opio. 

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