A vegetable juice, or thick, transparent, tasteless fluid, which sometimes exudes from certain species of trees. It is very adhesive, and gradually hardens without losing its transparency; but easily softens again when moistened with water. The gum most commonly used is that which is procured from different species of the Acacia in Egypt, Arabia, etc.; it is known by the name of gum arabic. Gum likewise exudes abundantly from the common wild cherry tree of this country: it exists also in various plants in the state of mucilage, especially in the roots and leaves. It is most abundant in bulbous roots; and of these, the hyacinth affords the largest quantity. Gum readily dissolves 4 0 in water, and the solution, which is thick and adhesive, is known by the name of mucilage. It is also soluble in the vegetable acids, but is decomposed by the sulphuric, nitric, and muriatic acids. It is insoluble in alcohol and ether.