GULUN'CHA, cocculue eordifollus, a plant of the same genus which yields calumba (q.v.), extensively used in the East Indies as a tonic and febrifuge. It is largely cultivated in some parts. It is a climber, with heart-shaped leaves. It exhibits a wonderful tenacity of life. When it has acquired the diameter of half an inch, it is not unusual to cut from the main stem a portion of from 20 to 30 ft. in length, when the part sustained by the branches of the tree sends down threads to the ground, which take root, and become new stems. To plant it, a few yards of the stem are merely made into a coil, and hung on the branch of a tree (Tenuent's Ceylon).
GUM, a general term applied to certain exudations from trees and plants, which are very different in their chemical characters and their general properties. In its strictest sense, gum is a substance which dissolves in water, forming a transparent mucilage; it is insoluble in ether, alcohol, and oils, either fixed or volatile, and is convertible into oxalic acid by the action of sulphuric acid. The gums to tins class are: 1. Gum arabic, which is gathered from the stems of acacia araica or acacia Dena, two leguminous trees found in northern Africa, and in some parts of Asia. It varies in color from a light straw to a garnet red, and is more or less transparent: the lightest is always the best. It is imported from Barbary and Turkey.
2. Barbary gum., a dark-colored variety, also imported from the Morocco coast. It has some qualities which render it particularly valuable to confectioners, in the manu facture of lozenges, etc. • It is the produce,of another species of acacia, A. gummilera.
3. Gum gedda, an inferior quality of Barbary gum.
4. Gum scnegal is in fine large, round tears, generally larger than the finest gum arabic; it is, however, darker in color, being a sherry brown, with somethnes a slight pinkish tint perceptible on the surface of the drops or tears. It is found generally in the tropical parts of the western coast of Africa, and is yielded by two species of acacia, viz., A. senegal and A. scyal. It is much valued for dressing various textile fabrics, such as mnslins and silks, and is also used by confectioners for the finest kinds of lozenges, etc. The acacia arabica is also found in the East Indies, and is supposed to yield, with other species, the following gums known in commerce.
5. Gum gattie, which is imported very largely, and is produced in the Deccan, Concan, and in Guzerilt.
6. Gant babool, an inferior gum, imported from Bengal.
7. East Indian gum, a tolerably good variety, imported from Bombay.
8. Gum oomramuttce, an inferior variety, from the province of Oomrawuttee.
These East Indian gums are all dark colored, and are Much inferior to those pro duced in Africa; they are, however, extensively imported into the ports of London and Liverpool; over 200 tons are annually received into those ports.
The gums above described principally consist of a material which chemists have called arabin, from its being the chief constituent of gum arable. We now come to another class of gums, in which another material, called bassori a, from its being first noticed in an analysi?of gum balsam. is more or less present. These are: 1. Gum tragacanth, or dragon, yielded by the leguininous shrub astragalus traga eantha; it was known to the ancient Greeks under the name of tragalcantba. The finest pieces are in flakes, from an inch to an inch and a half in length, and from half an inch to an inch in width. This gum is more or less white, and nearly opaque, that which is whitest and most opaque being the best. It is only partly soluble in water, forming a white paste, instead of a transparent solution; with vinegar or dilute acetic acid it also, forms a similar paste, and is a valuable cement, holding • light materials with great tenacity. It is used as stiffening material for various textile fabrics, and is much valued for this purpose, where it is not desired to give gloss to the material. We receive it chiefly from Smyrna and Constantinople. It is mostly produced in northern Persia and Asia. 31 inor.
2. Gum kuteera, yielded by sterculia urens on the Coromandel coast. It is now only an occasional import, though formerly a considerable quantity was brought to this country.
3. Gum bassora. —This is imported from Bassora; 'hence its name; but although long known in commerce, it has not been satisfactorily determined what plant produces it. Only a very small quantity reaches this country front time to time.
4. African or Sierra Leone tiagacanta.—This is occasionally imported in small quan tities from western Africa, and is produced by eterculia tragacantha.
Besides the true ghms, there are the