KINO (apparently of East Indian origin). The concrete exudation of certain tropical trees, especially the Pterocarpus marsupium (natural order Leguminosæ), growing in the East Indies, which yields ‘East Indian kino.’ East Indian kino is the kind which now chiefly occurs in commerce, and is the ordinary kino or gum kino of the shops. It is in small angular glistening fragments, the smaller reddish, the larger almost black. Thin pieces are ruby-red. It is brittle and easily powdered, has no smell, but a very astringent taste. Bengal kino is a similar astringent substance, produced by Butea frondosa. ‘Botany Bay kino’ is the produce of Eucalyptus resinifera.
Kino is soluble in alcohol, but very sparingly soluble in ether and in cold water. Its chief constituents are: Kinotannic acid, C18H18O8; pyrocatechin, C6H4(OH)2; and kino red, a product of oxidation of kinotannic acid. The astringency of kino is mainly due to its containing kinotannic acid, and in consequence of this property it is employed in medicine in certain forms of diarrhœa (especially when a flux seems to be kept up by want of tone in the intestinal capillaries), the best mode of prescribing it being as compound kino powder, which is a mixture of kino, cinnamon, and opium, the dose for an adult ranging from ten grains to a scruple. The medicinal tincture of kino forms an excellent gargle for the relaxation of the uvula; it contains kino, glycerin, alcohol, and water. Kino is employed to a considerable extent in the East Indies as a cotton-dye, giving to the cotton the yellowish-brown color known as nankeen.