CAMPHOR is a solid essential oil which is found in many plants, and may be separated from many essential oils. It particularly abounds in certain species of the natural order lauraear (q.v.). Almost all the C. of commerce is the produce of the C. laurel or C. tree (camphora etch:arum, formerly known as laurus cantphora), a native of China, Japan, Formosa, and Cochin-China, and which has been introduced into Java and the West Indies. The genus cantphora differs from cinnarnarnum, (see CINNAMON) chiefly in having a thin instead of a leathery calyx. The C. laurel is a tree of considerable height, much branched, with lanceolate, evergreen leaves on short stalks, and small yellowish-white flowers in axillary and terminal panicles. The fruit is in size and appearance not unlike an imperfectly ripened black currant. Every part of the tree, but especially the flower, smells strongly of camphor. The wood is light and durable, not liable to be injured by insects, and much valued for carpenter's work. In the extraction of C. from the C. laurel, the wood of the stem and branches is chopped up into fragments, and introduced into a still with water, and heat applied, when the steam generated carries off the C. in vapor. These vapors rise, and in passing through rice straw, with which the head of the still is filled, the C. solidifies, and is deposited round the straw in minute grains or particles, somewhat about the size of raw sugar or coarse sand. These grains of impure C. are detached, and being introduced into a large globu lar glass vessel in quantities of about 10 lbs., are reheated, when first the water rises in steam, and is allowed to escape at a small aperture; and thereafter, this aperture being closed, the C. sublimes and resolidifies in the interior upper part of the flask, as a semi transparent cake, leaving all the impurities behind. The flasks are then cooled and broken by throwing cold water on them, and the C. taken out, and sent into market. The glass globes employed are called by an Italian name, bomboloes, the sublimation of C. having been first practiced in Venice.—C. was unknown to the Greeks and Romans, and was first brought to Europe by the Arabs. It is a white tough solid, slightty lighter
than water, and floats thereon. It is very sparingly soluble in water, but freely soluble in alcohol, ether, acetic acid, and the essential oils. It fuses at 347°, and boils at 399°, and when set fire to, is very inflammable, and burns with a white smoky flame. Thrown upon water, it floats, and may be set fire to, when the currents generated alike from the solution in water and the irregular burning of the pieces, canse a curious rotatory motion.. It has a peculiar hot aromatic. taste. and nn agreeable characteristic odor, C. is used in medicine, both internally and externally, as a temporary stimulant. It is frequently employed in gout and rheumatism. In small doses, it acts as an anodyne • and antispasmodic; in very large doses, it is an irritant poison. It is generally reckoned an anaphrodisiac. Its alcoholic solution and liniments in which it is the principal ingredient, are much used for external application in sprains and bruises, chilblains, chronic rheumatism, and paralysis.—The effluvia of C. are very noxious to insects, and it is therefore much used for preserving specimens in natural history.
The Borneo C. or Sumatra C. of commerce, sometimes called bard C., is the produce of dryobalanops aromatica, a large tree of the natural order The C. is obtained by cutting down the tree, and splitting it into small pieces; being found in crystalline masses in natural cavities of the wood. To this substance, the Chinese ascribe extraordinary medicinal virtues, so that it is sold among them at more than 50 dines the price of common camphor. It is seldom brought to Europe as an article of commerce.—The dryobalanops aromatics yields also a pale-yellowish limpid fluid, which gushes out when deep incisions are made in the tree with an axe, and which is generally called liquid C. or C. oil. It is sometimes imported into Europe. It has a smell somewhat resembling that of C., but more aromatic, like oil of cajeput. It is supposed to be from this fluid that the crystalline hard 0. is deposited. See BORNEENE.