A′den, a seaport town and territory belonging to Britain, on the south-west coast of Arabia, in
a dry and barren district, the town being almost entirely closed in by an amphitheatre of rocks, and possessing an admirable harbour. Occupying an important military position, Aden is strongly fortified and permanently garrisoned. It is of importance also as a coaling station for steamers, and carries on a great amount of commerce, forming an entrepôt and place of transhipment for goods valued at £6,000,000 a year. Its greatest drawback is the scarcity of fresh water, which is obtained partly from wells, partly from rock-cisterns that receive the rain, and partly by condensation from salt water—the only unfailing means of supply. The peninsula on which it stands somewhat resembles the rock of Gibraltar, and could be rendered as formidable. Aden was a Roman colony, and in the Middle Ages it was a great entrepôt of the Eastern trade. It was acquired by Britain in 1839, after which it was attacked repeatedly by the Arabs. With the additional territory latterly acquired, the total British area is 75 sq. miles (or with the island of Perim, 80); while a large tract is under British influence. Aden is attached to the Bombay Presidency. Pop. 46,165.
Adenanthe′ra, a genus of trees and shrubs, natives of the East Indies, nat. ord. Leguminosæ. A. pavonīna is one of the largest and handsomest trees of India, and yields hard solid timber called red sandal-wood. The bright scarlet seeds, from their equality in weight (each=4 grains), are used by goldsmiths in the East as weights.
Adeni′tis (Gr. adēn, a gland), in medicine, inflammation of one or more of the lymphatic glands.
Ad′enoids, small growths often occurring in the back wall of the throat in children, blocking the nostrils and commonly causing deafness. They can be removed by a simple operation.
Aderer′. See Adrar.
Aderno′, a town of Sicily, 18 miles N.W. of Catania and about 10 miles W.S.W. of Mount Etna. Pop. 25,000.
Adessena′rian, one of a sect of Christians which holds that there is a real presence of Christ in the Eucharist, but denying that it is effected by transubstantiation.
Adhesion, the tendency of two bodies to stick together when put in close contact, or the mutual attraction of their surfaces; distinguished from cohesion, which denotes the mutual attraction between the particles of a homogeneous body. Adhesion may exist between two solids, between a solid and a fluid, or between two fluids. A plate of glass or of polished metal laid on the surface of water and attached to one arm of a balance will support much more than its own weight in the opposite scale from the force of adhesion between the water and the plate. From the same force arises the tendency of most liquids, when gently poured from a jar, to run down the exterior of a vessel or along any other surface they meet.
Adian′tum, a genus of ferns; the maiden-hair fern.