MELALEUCA, in botany; a genus of the polyandria order, belonging to the polydelphia class of plants. The calyx is quinquepartite, superior; the corolla pentapetalous; the filaments are very numerous, and collected in such a manner as to form five pencils; there is one style; the capsule is half-covered with the calyx, formed like a berry, and is trivalved and trilocular.—This plant has already been noticed under the article (misfelt) MALALEUCA; where also, by mistake, it was said that there is only one species.—The species are five, natives of India and the South
Sea islands. The most remarkable species is the Leucadendron, from a variety of which (the latifolia, or broad-leaved leucadendron) the Cajeput oil is obtained: a medicine in very high esteem among the eastern nations, particularly in India. It is said to be obtained by distillation from the fruit of the tree. When brought into this country, it is a liquid of a greenish colour, of a fragrant but at the same time a very peculiar odour, and of a warm pungent taste. Some authors, however, represent this oil as being, when of the best quality, a white or colourless fluid; and it has been said by the authors of the Dispensatorium Brunsvicense, when prepared in Europe from the seeds sent from India, to be entirely of this appearance. Hitherto the oleum cajeput has been but little employed either in Britain or on the continent of Europe; but in India it is used both internally and externally, and is highly extolled for its medical properties. It is applied externally where a warm and peculiar stimulus is requisite; it is employed for restoring vigour after luxations and sprains, and for easing a violent pain in gouty and rheumatic cases, in tooth-ach, and similar affections; but it has been chiefly celebrated as taken internally, and it is particularly said to operate as a very powerful remedy against tympanitic affections.