METALS. 



465 



at Is. Qd. per grain, or 35 per ounce. It is 

 clear that our knowledge of the chemical prop- 

 erties of a substance so rare must necessarily 

 be but incomplete, as the difficulties of obtain- 

 ing exact or satisfactory results -with small 

 quantities of material are evident ; and, in fact, 

 the statements of the only person who has 

 worked upon the subject recently (Schafarik 

 Czudnowicz), instead of giving us any more 

 reliable information respecting the character 

 of vanadium, have only served to throw doubt 

 upon some of the conclusions of Berzelius, and 

 thus to render our knowledge even less com- 

 plete than it appeared to be. Hence it was 

 with much satisfaction that, in February, 1865, 

 Mr. Roscoe came into possession of a plentiful 

 source of vanadium in a by-product obtained 

 in the preparation of cobalt from the copper- 

 bearing beds of the lower Keuper-sandstone of 

 the Trias at Alderly Edge, in Cheshire. The 

 manager of the works was puzzled to know 

 why a blue solution, supposed by him to con- 

 tain copper, did not deposit the red metal upon 

 a strip of zinc ; the author recognized this re- 

 action as due to the presence of vanadium, and 

 secured the whole of the by-produot, which he 

 found to contain abont two per cent, of the 

 rare metal. The exact position of the vanadium 

 mineral in the sandstone beds cannot now be 

 stated, as the mine (at Mottram St. Andrews) 

 from which the cobalt ore was obtained is 

 now closed and cannot be entered. After a 

 long series of experiments, Mr. Koscoe has 

 proved to his own satisfaction that the sub- 

 stance supposed by Berzelius to be vanadium 

 (V=68.5) is not the metal, but an oxide, and 

 that the true atomic weight of the metal is 

 67.316=51.3. The metal itself has not yet 

 been obtained, but a compound of vanadium and 

 nitrogen has been prepared, shown by di- 

 rect analysis to contain 14 parts by weight of 

 nitrogen to 51.3 parts by weight of vanadium, 

 corresponding to the formula VN. The exist- 

 ence of this compound is proof positive of 

 the true atomic weight of the metal, and the 

 nitride serve's as the point of departure from 

 which to seek for the metal and the true chlo- 

 rides of vanadium, one of which, VC1 3 , has al- 

 ready been prepared by the action of chlorine 

 upon the nitride. It is a dark-brown liquid, 

 which decomposes when thrown into water, 

 forming a green solution containing V 2 O 3 . 

 The author demonstrated the fact that the oxy- 

 chloride, VOC1 3 , when thrown into water, de- 

 composes with formation of a yellow solution 

 of vanadium pentoxide, YaOs, while the tri- 

 chloride, VCls, on being similarly treated, 

 yields a green solution containing the metal in 

 solution as trioxide, V 2 O 3 . He then compared 

 these reactions with the decomposition of the 

 corresponding phosphorus compounds, POCls 

 and PC1 3 , forming P 2 O 5 and P 2 O 3 f obtaining 

 a precipitate of yellow silver phosphate in the 

 first case, and of black metallic silver in the 

 second. The characters of the vanadites 

 themselves bear out the analogy of the highest 

 VOL. vni. 30 A 



oxide with the corresponding oxides of phos- 

 phorus and arsenic. 



The author was of the opinion that vana- 

 dium, hitherto standing in no definite relation 

 to other elements, must be regarded as a mem- 

 ber of the well-known trivalent or triad class 

 of elementary substances comprising nitrogen, 

 phosphorus, boron, arsenic, antimony, and 

 bismuth. In conclusion, he remarked that 

 vanadium was the fourth substance supposed 

 by its discoverer to be a metal, which had in 

 recent years been shown to be a compound 

 body. The list he gives as follows : 



Titanium. Uranium. Niobium. 



Wollaston, 1823. Klaproth, 1789. j Hatchett, 1801. 

 Wohler, 1849. Peligot, 1849. } Rose, 1842-' 64. 



Marignac, 1865. 



Vanadium. 



Sefstrom and Berzelius, 1831. 



Molybdenum and Chromium. J. Eneu 

 Loughlin communicates to the American Jour- 

 nal of Science his experiments in the produc- 

 tion of these two metals. The method adopted 

 by Hjelm (in 1782) to procure molybdenum 

 was to heat the trioxide of the metal in a por- 

 celain crucible for two or three hours. Several 

 other plans have been tried, such as heating 

 the acid molybdate of potassium ; also the re- 

 duction of molybdate of ammonium by heat, or 

 the reduction of trioxide of molybdenum by car- 

 bonate of soda. Molybdenum is described as a 

 silver- white metal, not altered by contact with 

 air at ordinary temperature. Sp. gr. 8.5 ; not 

 attacked by chlorohydric acid or dilute sul- 

 phuric acid. Strong sulphuric and nitric acid, 

 on the contrary, act very powerfully upon it, 

 with evolution of sulphurous acid and hy ponitric 

 acid. Having had occasion during June, 1867, 

 to use some molybdenum, Mr. Loughlin tried 

 the methods above stated ; they were all very 

 satisfactory as regards the yield of pure metal, 

 but the time was rather long. He then had 

 recourse to the reducing action of cyanide of 

 potassium. Molybdic acid was prepared and 

 tested according to Fresenius, pages 179 and 

 180, Qualitative Analysis. The result being 

 satisfactory as regarded the purity of the molyb- 

 dic acid, 10 grains of molybdic acid thus pre- 

 pared were mixed with 15 grains ^ of cyanide 

 of potassium, placed in a porcelain crucible, 

 which porcelain crucible, with the lid luted, 

 was placed in another crucible, then surrounded 

 by powdered animal charcoal and exposed to 

 a white heat for twelve minutes. At that 

 time the crucibles were removed, allowed to 

 cool, and examined; the porcelain crucible 

 was found lined with a brilliant silver-white 

 metal of a sp. gr. 8.56, which was not attacked 

 by chlorhydric acid, but violently attacked by 

 nitric acid with evolution of hyponitric apid 

 fumes ; it reduced oxide of mercury and oxide 

 of silver when triturated with these substances. 

 An analysis of this showed it to consist of 



Molybdenum, 98.7 



Tnnrarities Si0 2 , C, * 



100.0 



