TITANIUM, is a metal of a copper red colour, very difficult of fusion, solu ble in muriatic acid, from which it may be precipitated by a tincture of galls. This metal was discovered in 1793, by Klaproth. He obtained it from it mineral called red schorl. In this mineral he foUnd the oxide of a metal different from any other then known. To this, from Meriachan in Cornwall, where it was found, he gave the name of Menachanite, but he had not succeeded in reducing it to the metallic state. Klaproth afterwards analysed the menachanite, and found that it was precisely the same as the oxide of the metal which he discovered in red schorl. To this metal he gave the name of titanium. This metal has been found on ly in the state of oxide. Red schorl con. sists entirely of this oxide. It has been found in dill'erent countries, as in Spain, France, and Hungary. It is disseminated in the fine specimens of rock-crystal which are brought from Madagascar, crystallized in long brilliant needles ; the form of the primitive crystal being a six sided prism with two-sided summits ; that of the molecule is a triangular prism, with right angled isosceles bases. It is of a red, colour, of different shades. It is brittle, but the fragments are so hard as to scratch glass. The specific gravity is from 4.1 to 4.2. The other mineral, to which Klaproth has given the name of titanite, is composed of oxide of titanium, silica, and lime, nearly in equal propor tions. Its specific gravity is 3.5. Titanium was obtained by Vauquelin, by reducing the native red oxide. He mixed together 100 parts of this oxide with 50 of calcin ed borax, and 50 of charcoal, formed.in to a paste with oil ; and exposed the whole to the heat of a forge raised to Wedgwood. By this process lie ob tained a dark coloured agglutinated mass, having a brilliant appearance on the sur face. Titanium obtained in this way, is of a reddish yellow colour, shining and bril liant on the surface, and equally brilliant in some of its internal cavities.
Titanium seems to be one of the most infusible metals known. When the red oxide is exposed to heat in a crucible, it loses its lustre. By the action of the blow pipe it is deprived of its transparence, and becomes of a greyish-white colour. On charcoal it becomes still more opaque, and of a The artificial carbo nate of titanium, exposed to heat in a cru cible, loses of its weight, becomes yellow, and as it cools resumes its white colour. Titanium enters into combina tion with phosphorus, and forms with it a phosphuret. This was prepared by M. Chenevix, by exposing a mixture of phos phate of titanium, charcoal, and a little borax, in a crucible, to a very strong heat. The phosphuret which he obtained was in the form of a metallic button, of a pale white colour, brittle, and granular, and infusible by the action of the blow pipe. This metal enters into combina tion with the acids, and forms salts with them.
of into a phial, filled with muriate of ti tanium, there is put a stick of tin, and the bottle enclosed with a stopper, a faint rose colour will soon be visible in that part of the solution adjacent to the tin, which by degrees will deepen to an amethystine red, and extend through the whole liquor. If zinc be substituted in stead of tin, the solution will be first vio let, and at length indigo blue. Attempts have been made to alloy titanium with other metals, but without success. The white oxide, and also titanite, in sub stance, are said to afford, when mixed with enamel flux, a straw yellow colour ; and we are informed that it has been used in the porcelain manufactory at 86 vres, as an ingredient in rich browns ; but the difficulty of obtaining a regular and uniform tint, has at length occasioned it to be abandoned.