The drug which is at present recognized as the legitimate kind is East Indian, Malabar, or Amboyna kino, and is obtained from Pteτocarpus Marsupium, Roxb. (Leguminosen). It is collected in the Government forests of the Malabar coast, the collectors being required to pay a small fee for the privilege, and to perform the tapping carefully and without injuring the timber. The mode of obtaining the kino is by making a perpendicular incision, with lateral ones leading into it, in the trunk, a vessel being placed at the foot of the incision to receive the juice. When exuding it resembles red currant jelly, but hardens in a few hours after exposure to the air and sun. When sufficiently dried it is packed into wooden boxes for exportation. When these are opened it breaks up into angular brittle fragments of a blackish-red colour and shining surface. In cold water it is only partially dissolved, leaving a pale flocculent residue, which is soluble in boiling water, but deposited again on cooling. In spirit of wine, sp. gr. , 838, it is entirely soluble, affording a solution having an acid reaction, but the liquid by long keeping assumes a gelatinous condition. It is also soluble in caustic alkalis and to a large extent in a saturated solution of sugar, but is wholly insoluble in ether. In chemical composition kino appears to be nearly allied to Pegu catechu, but differs from it in not yielding catechin when exhausted by ether, but only a minute quantity of scaly prismatic crystals of a substance which is soluble in cold water, and thus more nearly resembles pyrocatechin. Pyrocatechin is, however, not present in the fresh bark or wood of the tree. Etti (1878) states that he has obtained kinoin, C 14 H 32 O 0 , from Malabar kino, while Hanbury and Fluckiger failed to obtain it from that drug, but found it in Australian kino. According to Bentley, kino-tannic acid, catechin (or probably pyrocatechin), and kino red are the essential constituents of Malabar kino. The first of these is precipitated from an aqueous solution of the drug by dilute mineral acids, and the last by boiling an aqueous solution of kino-tannic acid for some time, when it separates as a red precipitate. The chemical constitution of Malabar kino is therefore only imperfectly known. The quantity of kino collected in Madras is comparatively small, and is supposed not to exceed a ton or two annually, but it is often shipped from Cochin.

Bengal, Butea, or Palas kino—obtained from Butea frondosa, Roxb. (Leguminosae), a native of India and Burmah, well known under the name of the Palas or Dhak tree, and remarkable for its large orange papilionaceous flowers —also finds its way occasionally into British commerce. A portion is also obtained from Butea superba, Roxb., and Butea parviflora, Roxb. Butea kino does not stick to the teeth when chewed like ordinary kino, although like the latter it gives a red tinge to the saliva. It is usually more or less mixed with small fragments of bark. It is almost completely soluble in water, and to the extent of 46 per cent, in boiling alcohol, but different specimens vary in solubility. It is believed to contain about half its weight of kino-tannic acid, the remainder consisting of a soluble mucilaginous substance, and a minute quantity of pyrocatechin, which can be extracted by ether. In India Butea kino is used instead of the Malabar kino, and is called by the Hindus kueni or kuenee.

Botany Bay, Australian, or Eucalyptus kino is a more or less resinous astringent exudation obtained from several species of Eucalyptus. It is found in flattened cavities in the trunks, and is mostly collected by sawyers and woodsplitters. It frequently comes into the London market, and the best variety, probably the product of E. corymbοsa, Sm., is used under the name of “red gum” in the preparation of astringent lozenges for sore throat. According to Wiesner of Vienna, Australian kino contains a little catechin (a statement doubted by Fluckiger) and pyrocatechin, no pectinous matter, but a gum nearly allied to that of acacia. Fluckiger also obtained from it kinoin, C 14 H 12 O 6 , which he regards as the methylated gallic ether of pyrocatechuic acid, viz., C 6 H 4 (OCH 3 )C 7 H 5 O 5 .

Between 1808 and 1820 a substance was met with in French commerce under the name of Jamaica kino, which is said to have been prepared by inspissating the juice of the seaside grape, Coccoloba uvifera, L. (Polygonaceae). When powdered it has a somewhat bituminous odour and an astringent slightly bitter taste. It is but little soluble in cold water or alcohol, but dissolves almost entirely in boiling water, and to the extent of about 75 per cent, in hot alcohol. In thin laminae it is only semi-transparent, the fragments usually met with in commerce being quite opaque. In 1835 an article appeared in French commerce under the name of “kino de la Colombie,” which is stated in Histoire des Drogues to be in all probability an extract of the bark of Hhizophora Mangle, L. A liquid kino is obtained from Pterocarpus indicus, which does not harden like that obtained from P. Marsupium. Although used in India it is not imported into Europe. Other varieties of kino are mentioned in the same work, but they must be regarded rather in the light of curiosities than as articles of commerce.

Kino is used in medicine as an astringent, chiefly in the form of tincture; but, owing to its tendency to gelatinize, that preparation is much less used than formerly.

See D. Fothergill, Med. Obs., 1757, p. 358; F. Moore, Travels into the Inland Barts of Africa, 1737, p. 160, 209, 267; Histoire des Drogues, 7th ed., tom. iii. p. 426-439; Lewis, Materia Medica, 1784, p. 366; Daniell, Pharmaceutical Journal, (1) xiv. p. 55; Pharmacographia, 2d ed., p. 195; Pereira, Mat. Med., 4th ed., vol. it, pt. in, p. 325; Bentley and Trimen, Medicinal Plants, Nos. 79-81.