CINCHONA, a most important genus of trees of the natural order einchonao,ce; yield ing the bark so much valued in medicine, known as Peruvian bark, Jesuits' bark, China bark, quina, quinquina, cinchona bark, etc., and from which the important alkaloids quinia or quinine (q.v.), and einehonia or einchonine, are obtained. The species of this genus are sometimes trees of great magnitude; but an after growth springing from their roots when they have been felled, they often appear only as large shrubs; and some of them in the highest mountain-regions in which they are found, are low trees with stems only eight or ten feet in height. They exist only in South America, between s. hat. 20° and n. lat. 10°, and chiefly on the eastern slope of the second range of the Cordilleras. All the cinchonas are evergreen-trees; with laurel-like, entire, opposite leaves; stipules which soon fall off; and panicles of flowers, which, in general appearance, are not unlike those of lilac or privet. The flowers are white, rose-colored, or purplish, and very fragrant. The calyx is small and 5-toothed; the corolla tubular with a salver shaped 5-cleft limb. In the true cinchonas, the capsule splits from the base upwards; the species in which it splits from above downwards form the sub-genus easearilla; the distinction acquiring importance from the consideration, that the barks of the former alone contain the alkaloids so valuable in medicine; and this property is further limited to those species which have the corolla downy or silky on the outside. Beyond the botanical limits thus narrowly marked out, not a trace of these alkaloids has yet been. discovered anywhere.
Great difficulty has been found in determining the species by which the different varieties of C. bark known in commerce are produced. The common commercial names are derived partly from the color of the kinds, and partly from the districts in which they are produced, or the ports where they are shipped. It appears, however, to be now ascertained that calisaya bark, also called royal or genuine yellow bark, one of the very best kinds—mostly shipped from Arica—is chiefly the produce of C. calisaya, a large
tree, growing in hot mountain valleys of Bolivia and the south of Peru. To give all the varieties of bark and species of tree would go beyond our limits.
The accurate discrimination of the different kinds of bark requires much experience. The taste is always bitter; but it is possible even to distinguish by the taste those varie ties which contain quinia most laro-ely from those in which cinchonia is most abundant.
The cutting and peeling of C. trees are carried on by Indians, who go in parties, and pursue their occupation during the whole of the dry season. They build a hut, which serves both for their abode and for drying the bark. The trees arc felled as near the root as possible, that none of the bark may be lost; and the bark being stripped off, is carefully dried; the quilled form of the thinner bark is acquired in drying. The bark is made up into packages of various size, but averaging about 150 lbs. weight, closely wrapped in woolen cloth, and afterwards in hides, to be conveyed on mules' backs to the towns. These packages are called drums or seroons. It is in them that the bark is always brought to Europe.
A number of spurious kinds of Peruvian or C. bark are either sent into the market separately, or are employed for adulterating the genuine kinds. They are bitter barks, and have, in greater or less degree, febrifugal properties, but are chemically and medicinally very different from true C. bark. They are produced by trees of genera very closely allied to cinchona.
Whilst C. trees have been becoming every year more scarce in their native regions, no attempt has been made to cultivate them there, notwithstanding the constantly increasing demand for the bark; but the Dutch have recently made extensive plantations of them in Java; and the same has been done in British India, from seeds and plants obtained from the South American governments, by Mr. Markham. In the course of his researches in South America, Mr. Markham found only one C. tree planted by human bands. See PERUVIAN BARK.