TUNGSTEN

(Swedish tung sten, heavy stone.) The ores of this metal are the native tungstate of lime, and the tungstate of iron and manganese; the latter mineral is known under the name of yVolfram. Tungsten is a white, hard, and brittle metal, very difficult of fusion, and having the high specific gravity of 174. Heated to redne in the open air, it burns into the peroxide, or tungstic acid. The equivalent of tungsten is probably about 100; and the tungstic acid consists of 1 atom of metal and 3 atoms of oxygen (8 x 3 = 24), and is represented by the equivalent 124. This metal was discovered by Me rs. Delhuyart. It is sometimes called Wolframium, and also Scheelium, in honour of Scheele, who first examined the nature of tungstate of lime. [s. 1282]