Description and Properties. - The dried root of Atropa Belladonna, yielding when assayed not less than 0.5 per cent. of mydriatic alkaloids. The root occurs in cylindrical, tapering, longitudinally wrinkled pieces, 1/2 to 1 inch (12-25 Mm.) thick; externally brownish-gray, internally whitish; fracture nearly smooth and mealy, not radiating or showing medullary rays in the thicker roots, except in the layer near the bark; nearly inodorous, of sweetish taste, afterward bitterish and strongly acrid.

The root contains the same constituents as the leaves, with the exception of chrysa-tropic acid - which is wanting - and in addition a red coloring-principle, atrosin, found also in the berries. Young roots have been found to contain proportionately higher percentages of hyoscyamine. The unripe berries contain hyoscyamine, while the process of ripening seems to either convert this alkaloid into atropine or larger quantities of atropine are conveyed to the berries at ripening.

Official Preparations

Fluidextrctum Bellad&nnae Ridicis - Fluidextrcti Bellad&nnae Rdicis -Fluidextract of Belladonna Root. - Dose, 1-3 minims (0.06-0.18 Cc.) [1 minim (0.05 Cc), U. S. P.].

Linimntum Belladnnae (95 per cent.)Linimenti Belladonnae - Belladonna Liniment. - For external use.

Formula: Camphor, 50; fluidextract of belladonna root, 950.