Gum Arabic
a gum obtained from the Acacia arabica, which grows abundantly in India and Arabia. It is yielded also by A. speciosa in India, A. nilotica and A. seyal in Arabia, A. tortilis and A. ehrenbergiana in tropical Africa, A. mollissima and affinis supply a similar gum in Australia. Gum arabic can be obtained also from Vachellia farnesiana of India, a small tree closely allied to the true acacias; a gum akin to it is derived from Terminalia belerica, a Myrobalan.
Gum arabic occurs in transparent white tears, which are often colored yellow or brown by impurities. It dissolves in water, and the solution gives a precipitate of arabin on the addition of hydrochloric acid. Gum arabic contains about 70 per cent. of arabin, and 17 per cent. of water; the rest consists of potash and lime, which were combined with the arabin. Gum is insoluble in alcohol. By the action of nitric acid it is converted into mucic, saccharic, and oxalic acids.
GUMMERE GUN POWDER