The New International Encyclopædia/Vanadium

VANADIUM (Neo-Lat., from Vanadis, a Scandinavian goddess). A metallic element discovered by Sefstrom in 1830. It is never found native, but occurs in combination as vanadic acid in a number of minerals, including descoloizite, endlichite, motthamite, psittacinite, roscoelite, and vanadinite. It has also been found in the lava at Vesuvius and spectroscopically in the sun. It is a difficult metal to obtain pure, but was isolated by Roscoe by heating the anhydrous dichloride in pure dry hydrogen.

Vanadium (Symbol, Va: atomic weight, 51.38) is a light-gray powder that has a specific gravity of 5.5 and melts at a very high temperature. The metal combines with platinum to form an alloy, and with oxygen forms a monoxide, a dioxide, a trioxide, a tetroxide, and a pentoxide, of which the last two act as acid-forming oxides, forming hypovanadic and vanadic compounds. Of the various vanadium salts, ammonium metavanadate, formed by dissolving the pentoxide in ammonium hydrate, is used as a black pigment, frequently with aniline as a dye, and also as the basis of a permanent black ink.