CINCHONA, a genus of Monopetalous Exogenous Plants, the dif ferent species of which have a great reputation in medicine. It consti tutes the type of the natural order Cuschonacem. It is known by the following characters :—Tube of the calyx top-shaped, with a per manent 5-cleft limb. Corolla with a taper tube, and a 5-parted limb, which is valvate in motivation. Filaments short, inserted into the middle of the tube, within which the linear anthers are altogether inclosed. Stigma 2-cleft, a little elevate. Capsule ovate or oblong, slightly marked on each side by a furrow, 2-celled, crowned by the calyx, dividing through its diasepimenta into two halves. Placenta long. Seeds numerous, erect, imbricated upwards, compressed, with a broad membranous winged border; albumen fleshy. Trees or shrubs, with a bitter aromatic astringent bark. Leaves on short stalks, with flat edges. Stipules ovate or oblong, leafy, separate, deciduous. Flowers in terminal panicled corymbs, white, or of a rosy-purple colour.
By whom the important properties of the various species of this genus were first made known to Europeans is unrecorded ; for it is not worth repeating the fables that have been invented upon the subject The native Peruvians, who call the trees Kina, or Kinkel), attach no febrifugal importance to the bark, but are said even to have • prejudice against its employment. Its introduction to Europe took place through the Spaniards in the year 1640, and it is pre tended that a certain countess Chinchon, vice-queen of Peru, having experienced the good effects of the bark as a febrifuge, it gained the name of Pulvis Comitissm, and under that name, or as Pulvia Jesuiticus, was vended by the Jesuits, who derived a considerable part of their wealth from its trade. Humboldt regards a tradition still current in Loxa as a more probable explanation of the discovery of the properties of Cinchona. It is said that the Jesuit missionaries there had endeavoured, according to the custom of the country, to distinguish the different kinds of trees by chewing their bark, and that this had led them to observe the remarkable bitterness of Cinchona. Those who were medical among them were thus led to try an infusion of the bark in tertian agues, which are very common at Loxa, and thus the discovery of its power was made. Little was known of the tree producing this substance till the voyage of La Condamine, who, in 1738, first printed a detailed account of Quinquina, as it was then called. Since that time the attention of botanists has been constantly directed to the subject, and e good deal of information has upon the whole been collected ; the general facts connected with the habitation, geographical range, modes of preparation, and botanical distinctions of the species have been ably stated by Humboldt, Ruiz and Pavon, Ede, De Candolle, Lambert, Ptippig, and Lindley, and will form the basis of the nue ceeding short, account ; but in all the minor details regarding the barks themselves, and the species that furnish them, Europeans are still much in the dark.
To this genus botanists have from time to time referred plants which, upon a more careful examination, have been ascertained not to belong to it ; West Indian, Brazilian, and even East Indian Cinclionan, thus have found a place in books, but they are really referrible to other genera. Circumscribed within the limits of the preceding character, Cinchona will be found a mountainoue genus confined to the Cordilleras, between La Paz, in about 22' S. let, and Santa Martha, near 10' N. lat.; a line having those northern and southern limits, and bounded by the most eastern part of the Cordilleras on the one hand and the Pacific on the other, will very nearly define the corner of the globe inhabited by true Cinchonas. \Vithin these limits they occur on the plains, but chiefly on mountain sides as far as 10,000 feet of elevation above the sea, the principal sone being at from 1800 to 6600 feet of elevation. In these places the mean temperature is estimated by Humboldt at from 17' centigrade, or 62.6' Fahrenheit, to 12' centigrade, or Fahrenheit The manner of collecting the Huanuco Bark of commerce is thus described by Poppig (' Companion to the Botanical Magazine,' vol. i. p. 249). " In the month of April the preparations for an expedition commence ; and in May the people start for the forest, whence the last green bales are transmitted home in November. They fell the trees close to the root, sparing those trunks which appear too young (pales verdes), as, till they have attained maturity, the bark is of no value. The next process is to divide (trozar) the stems into pieces of uniform length, rejecting only the very smallest branches. With a peculiar kind of knife, made for the purpose, the bark is cut length wise, and a certain degree of practice is necessary to perform this operation properly so as to remove the rind without injuring the wood or severing any of the fibres. With the same instrument they take off the stripes (longos) of the bark as broad as possible ; but this however is not done for three or four days after the tree is felled, as before that time the moisture that exists between the cuticle and the wood would prevent the bark from severing into such large pieces as fetch the highest price. A worse consequence ensues from stripping the genie too quickly, as then the thin grey or blackish epidermis shivers off; and from the presence of this outward rind, covered with many cryptogamia, the value of the bark in the European market is mainly estimated. The English purchasers in particular hold the notion that the bark is most powerful recording as its epidermis is covered with spots.