A gummy exudation obtained by making incisions in the stems of Astragalus gummifer and some other species of Astragalus. Asia Minor.

Characters. - Shell-like bands, slightly curved, white or yellowish, tough and elastic; very sparingly soluble in cold water, but swelling into a gelatinous mass, which is tinged violet by tincture of iodine.

fig. 187. - Tragacanth., half the natural size.

Composition

Composition. - Consists of a mixture of arabin, or common gum-arabic; and bassorin, a gum which does not dissolve in water, but swells up in it.

Preparations

S.P.

Dose.

Confectio Opii ............................................

.5-20 gr.

" Sulphuris ..............................

.60-120 gr.

Glycerinum Tragacanthae ....................

6 grs. to 1 fl. oz.

Mucilago " ................

1 fl oz. or more.

Pulvis Opii Compositus ...................................

.2-5 gr.

„ Tragacanth ae Compositus..

.20 gr. upwards.

U.S.P. Mucilago Tragacanthae

Mucilago Tragacanthae. Mucilage of Tragacanth. - Tragacanth, 60 gr.; water, 10 fl. oz. (B.P.). Tragacanth, 6; glycerine, 18; water up to 100 (U.S.P.).