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SCIENCE 



[N. S. Vol. XXVIII. No. 721 



tion of titanous salts as reducing agents 

 in volumetric analysis. 



"Mineral Resources for 1906" reports 

 a small production of rutile, chiefly from 

 Virginia, as against no production in 

 1903; also large deposits of titaniferous 

 iron ores from North Carolina, Wyoming 

 and the Adirondack region. The con- 

 stant advances made in the metallurgy of 

 this element seem to assure an advancing 

 prominence. 



Passing to group (5) we find first on 

 our list the element vanadium. Few of 

 the elements which we have to consider 

 are of such general interest. Its five dis- 

 tinct conditions of oxidation, with their 

 salts, well-defined in most cases, furnish 

 the chemist with a fascinating field for 

 experimentation, as witness the many vol- 

 umetric processes which concern them- 

 selves with this element, and the volumin- 

 ous published work upon the salts of tetra- 

 and trivalent vanadium. 



Among the uses which have been found 

 for vanadium are its employment in the 

 making of a photographic developer, a 

 fertilizer for plants, coloring material for 

 glass, and with anilin, a black dye. 

 Vanadyl phosphate has been found to 

 behave physiologically like potassium 

 permanganate. Vanadie acid (V2O5) is 

 employed as a substitute for gold bronze, 

 in the making of a water-proof black ink 

 with tannic acid, in the manufacture of 

 sulphuric acid by the contact process, and 

 as a catalyzer to accelerate oxidation proc- 

 esses, such as the oxidation of sugar to 

 oxalic acid, of alcohol to aldehyde, and of 

 stannous to stannic salts. 



Probably of more importance than any 

 of these uses of vanadium is its employ- 

 ment in the manufacture of steel, as de- 

 scribed in the pamphlets written by Mr. J. 

 Kent Smith, of the American Vanadium 

 Co. From these we learn of the remark- 

 able elasticity and tensile strength of 



steels containing from .15 to .35 of one 

 per cent, of vanadium introduced as ferro- 

 vanadium, an alloy containing about 30 

 per cent, of vanadium. This important 

 commercial use of the element has stimu- 

 lated the search for its ores, a search 

 which has resulted in our own country in 

 several discoveries, chief of which is that 

 of carnotite in Routt County, Colorado. 

 Of interest in this connection are the ex- 

 tensive deposits of vanadium ore discov- 

 ered in Peru less than two years ago, and 

 found to contain a sulphide, essentially 

 VS4, named by Hewett patronite, and 

 found by Hillebrand to contain from 18.5 

 per cent, to 19 per cent, of vanadium. Of 

 value to the student of this element are 

 three recent pamphlets, "Das Vanadin und 

 seine Verbindungen, " by Ephraim, 1904, 

 "Die Literatur des Vanadins," by 

 Prandtl, 1906, and "Le Vanadium" by 

 P. Nicolardot, published by Gauthier-Vil- 

 lars, Paris. 



Probably no one of the elements which 

 we have to consider has made a more phe- 

 nomenal leap from practical obscurity to 

 comparative prominence than has tanta- 

 lum. In the index of the Z entralhlatt for 

 1903 we find no mention of this element, 

 while the index for 1905, the year of the 

 first application of tantalum to incandes- 

 cent lighting contains twenty references to 

 it. The use of the tantalum filament as a 

 substitute for carbon is certainly an inter- 

 esting step in the development of incandes- 

 cent electric lighting. The tantalum lamp 

 produces a light of one candle power for 

 every two watts of electrical energy, as 

 against three and one tenth watts required 

 by the ordinary carbon filament. Tan- 

 talum is said to be as hard as steel and aa 

 resistant to chemical action as gold. These 

 qualities are responsible for a patent for 

 its use in pens. 



A catalogue'^ of the mineral sources of 

 " Zeitsch. f. aiigen. Ohem., 1905. 



