commercial importance; the use of pure rubber has been greatly superseded by that of “vulcanised” rubber; mixed with from 1/40 to 1/2 of its weight of sulphur and combined by heat, the rubber acquires greater elasticity, is not hardened by cold or rendered viscid by heat, and is insoluble in many of the solvents of pure rubber; its usefulness is thus largely increased and greatly extended of late; the demand for rubber is in excess of the supply, but no substitute has been found effective; in recent years care has been bestowed on its economical collection and on its scientific culture.

INDICTION, a cycle of 15 years instituted by Constantine the Great, and which began on the 24th September 812, the day of his victory over Maxentius; to find the indiction of any year add 1 and divide by 15.

INDIUM, a metallic elementary body of rare occurrence, and first discovered in zinc-blende in 1863.

INDIVIDUALISM, the name given to a social system which has respect to the rights of the individual as sovereign, and is strictly opposed to Socialism.

INDO-CHINA, called also the Eastern Peninsula or Farther India, the name given to the large peninsular territory which lies between the Bay of Bengal and the Chinese Sea, lying almost wholly within the Torrid Zone, and embracing the empires of Burma and Annam and the kingdom of Cambodia and Siam, as well as territories under Britain and France, all now mostly divided between the latter two and Siam; it is sparsely peopled owing to its mountainous character and the swampy lands, and the natives are mainly of the Mongolian type.

INDO-EUROPEAN, an epithet applied to a family of the human race with the languages of its several members descended from the Aryans, and found dispersed over an area including the better part of India and Europe.

INDO-GERMANIC, a term at one time employed especially among German writers, synonymous with Aryan.

INDORE, 1, a native principality (1,094), in Central India, somewhat larger than Wales, embraces the Vindbya and Satpura Mountains, and is traversed by the Nerbudda River; there are great forests on the mountains; the valley of the river is fertile; wheat, sugar, cotton, tobacco, and large quantities of opium are raised; the climate is sultry, and at certain seasons unhealthy; the natives are chiefly Mahratta Hindus; among the hills are Bhils and Gonds, the wildest tribes of India; the State is governed by a Maharajah styled Holkar, under supervision of an agent of the Governor-General; education is progressing.  INDORE, 2, on the Kuthi River, the capital (92), is a poor city of brick and mud; the palace and the British residency, however, are fine buildings; it is connected by rail with Bombay, distant 400 m.  SW., and with Ajmere; it was the scene of a British massacre in 1857.

INDRA, the king of heaven and national god of the Aryans; gives victory to his people, and is always ready to aid them; he is pre-eminently a warlike god, and as he stands on his war-chariot, drawn by five fawn-coloured horses, he is in a sort the type of an Aryan chieftain; he is sometimes assisted by other gods, but he more frequently fights alone; he is the dispenser, moreover, of all good gifts, and the author and preserver of all living; his power extends over the heavens, and he holds the earth in the hollow of his hand.