The British pharmacopoeia / published under the direction of the General Council of Medical Education and Registration of the United Kingdom, pursuant to the Acts XXI. & XXII. Victoria, CAP. XC. (1858) and XXV. & XXVI. Victoria, CAP. XCI. (1862).

General Medical Council.

Date:: 1899

Credit: The British pharmacopoeia / published under the direction of the General Council of Medical Education and Registration of the United Kingdom, pursuant to the Acts XXI. & XXII. Victoria, CAP. XC. (1858) and XXV. & XXVI. Victoria, CAP. XCI. (1862). Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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$THE BEITISH PHAEMAOOPCEIA. The names of substances defined in the text are printed with capital initial lettei's; those defined in an Appendix are printed in italics. AOAOI^ GUMMI. Gum Acacia. A gummy exudation from the stem and branches of Acacia Senegal, Willd. [Bentl. and Trim. Med. PI. vol. ii. plate 94], and of other species of Acacia, Willd. Characters and Tests.—In rounded or ovoid tears, or masses, of various sizes ; or in more or less angular frag- ments with glistening surfaces; nearly colourless, often with a yellowish tint. The tears are opaque from numerous minute external fissm^es, and very brittle; the fractured surfaces are vitreous in appearance. Taste bland and mucilaginous; nearly inodorous; insoluble in alcohol (90 per cent.), but entirely soluble in ivater, forming a translucent viscid solution which feebly reddens litmus. When dissolved in an equal weight of tvater, the solution should neither form a glairy mucilage nor, after admixtm^e with more water, should it yield a gummy deposit on standing. The aqueous solution forms with solution of lead suhacetate an opaque, and with solution of borax a more or less translucent, white jelly; it gives no precipitate with solution of lead acetate; is not coloured blue or brown by a small quantity of solution of iodine (absence of starch or of ordinary ' dextrin' of com- merce) nor bluish-black by test-solution of ferric chloride (absence of tannic acid); and does not give a red precipitate when boiled with solution of potassio-cupric ia7-tratc (absence of certain sugars). Gum Acacia should not yield more than 4 per cent, of ash. u$