TUNGSTEN, W

Atomic weight 184.0. Also known as Wolfram. sten is a metallic element belonging to the chromium group. It is a fairly uncommon metal, not very widely distributed but occurring in appreciable quantities in certain localities. Wolframite, a tungstate of iron and manganese, is found in many parts of the United States, in England, and in other parts of Europe, and in Australia, Canada, and parts of South America. Scheelite,. Ferberite, Hub nerite and Stolzite are other ores of tungsten. It is a hard, brittle metal, grey in color, and very heavy, having a specific gravity of 18.77. It melts at about 3270°C. and this high melting point, combined with its other properties renders it suitable for the manufacture of filaments for incandescent electric lamps, for which purpose it is widely used. It also finds application in the steel industry, tungsten | steels being of considerable industrial importance, while various other alloys are prepared with it. It is soluble in nitric acid, while sulphuric and hydrochloric acids act upon it slowly. Hot pota ium hydroxide solution di olves it with the formation of pota ium tungstate. At ordinary temperatures it is resistant to the action of air or | moisture, but at a red heat it burns in air with the formation of the trioxide. The smelting of the metal is now included among the ‘key’ industries. Tungsten is mainly consumed in the manufacture of high-speed steels. Tools made from steels containing 14 and 18. per cent. tungsten retain their cutting edge while running red hot. The pure metal is used for electric lamp filaments. The salt sodium tungstate is employed to render fabrics ‘nonble,’ and as a mordant in dyeing. _TUNGUSES, Asiatic Ural-Altafe or Sibiric people, consisting of northern Tungis (on the ur, and island of Saghalien), southern Tungus, Golds of the Amur, Lamuts of the Sea of Okhotsk, and Manchus.