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Rh the chief sources being vanadite, mottramite, descloizite, roscoelite, dechenite and pucherite, whilst it is also found as a constituent of various clays, iron-ores and pitchblendes. Vanadium salts may be obtained from mottramite by digesting the mineral with concentrated hydrochloric acid, the liquid being run off and the residue well washed; the acid liquid and the washings are then evaporated with ammonium chloride, when ammonium metavanadate separates. This is recrystallized and roasted to vanadium pentoxide, which is then suspended in water into which ammonia is passed, when ammonium metavanadate is again formed and may be purified by recrystallization. The pure metal may be obtained by reducing vanadium dichloride in hydrogen, the operation being exceedingly difficult (for details, see Roscoe's original papers). In a somewhat impure condition it may be obtained by the reduction of vanadium pentoxide with a mixture of the rare earth metals which are obtained by reduction of the waste oxides formed in the manufacture of thoria (Weiss and Aichel, Ann., 1904, 337, p. 380); from the oxide by Goldschmidt's thermite method (Koppel and Kaufmann, Zeit. anorg. Chem., 1905, 45, p. 352); by electrolysis in a bath of fused fluorspar containing a steel cathode and an anode composed of carbon and vanadium pentoxide (M. Gin, L'Electricien, 1903, 25, p. 5); and by the electrolysis of vanadium trioxide when heated in an evacuated glass tube (W. v. Bolton, Zeit. f. Elektrochem., 1905, n, p. 45). H. Moissan (Comptes rendus, 1896, 122, p. 1297) obtained a vanadium containing from 10 to 16% of carbon by fusing vanadic anhydride with carbon in the electric furnace. For other methods of obtaining vanadium and its compounds, see Cowper Cowles, ''Engin. and Mining Journ. 67, p. 744; Herrenschmidt, Comptes rendus, 1904, 139, p. 635; M. Gin, Elektrochem. Zeit., 1906, 13, p. 119; W. Prandtl and B. Bleyer, Zeit. anorg''. Chem., 1909, 64, p. 217.

Vanadium is a light-coloured metal of specific gravity 5.5. It is not volatilized even when heated to redness in a current of hydrogen, and it burns readily to the pentoxide when heated in oxygen. It dissolves slowly in hydrofluoric acid and in nitric acid, the solution turning blue; it is insoluble in hydrochloric acid. When fused with caustic soda, hydrogen is liberated and a vanadate is formed. It precipitates platinum, gold and silver from solutions of their salts, and also reduces mercuric, cupric and ferric salts. It absorbs nitrogen when heated in a current of that gas, forming a nitride. Vanadium may be detected by converting it into the pentoxide, which on passing sulphuretted hydrogen through its acid solution becomes reduced to the dioxide, the solution at the same time becoming lavender blue in colour; or if zinc be used as a reducing agent, the solution becomes at first green and ultimately blue.

VAN BEERS, JAN (1821-1888), Belgian poet, usually called "the elder " to distinguish him from his son, Jan van Beers, the well-known painter, was born at Antwerp on the 22nd of February 1821. He was essentially a Netherlander, though politically a Belgian, expressing his thoughts in the same language as any North Netherland writer. In fact, the poems of Jan van Beers are perhaps more popular in Holland than in Belgium, and of many of them there exist more editions printed in Holland than in his political fatherland. Van Beers started life as a teacher of Dutch language and literature, first at Malines, then at Lierre, and in 1860 was appointed a professor of both at the Athenaeum (high school) in Antwerp, where he had also been a sub-librarian in the communal library. Van Beers as a teacher was early in the field, with Hendrik Conscience, Willems and others, when the Flemish movement began. He composed a Dutch grammar (1852), which, in enlarged editions, still holds the field, and a volume of selections from Dutch authors, both books being so much appreciated that the Belgian government made them text-books in the public schools. Van Beers's historical poems, the principal