CHEELITE IN NOVA SCOTIA. — McCALLUM. 251 



grade, the remainder will probably average between 30 and 50 

 per cent, scheelite. 



So far, prospecting has been confined to a belt 200 feet wide 

 north and south, and a distance about 1200 feet east and west. 

 The total width of vein-matter in Ihe 200 feet would be about 

 50 inches. 



Wolframite has been known for centuries to German and 

 Cornish tin miners. It was found by experience that when 

 smelted with tin in the furnace it impeded the reduction of the 

 tin and facilitated its scorification, so it was thought it ate up 

 the tin, as the wolf eats the sheep. Hence the derivation of 

 the word wolfram. 



In Cornwall the miners termed it "call" or mock-lead on 

 account of its great weight, thinking it contained lead. But the 

 Swedish chemist, Scheele, proved in 1781 that this mineral, as 

 well as another which he had called tungsten, contained a speci- 

 fic mineral acid now called tungstic acid, and that wolframite 

 is essentially a tungstate of iron, and tungsten now called 

 scheelite, is tungstate of lime. 



These minerals were employed in 1840 by the English 

 chemist Robert Oxland for the preparation of tungstate of soda 

 to be used as a mordant in dyeing cloth, and as proposed by 

 Versmann and Lyon Playfair, for the impregnation of vege- 

 table tissues, linen and cotton, to render them non-inflammable 

 and almost fire-proof. 



Its greatest use is as an alloy with steel. Tungsten steel 

 was first made in 1855 in Austria, and was introduced to the 

 trade later by Musket, an Englishman. It makes armor plate 

 very tough and difficult to fracture and split. In projectiles 

 and high speed tools it forms an alloy which retains its temper 

 at a red heat. It makes car springs stiffer. It increases the 

 permanency of magnets and makes a more powerful response in 

 sounding plates and wires for musical instruments. 



It is commonly stated that it will take the place of carbon 

 in producing hardness, but this is not true. It is more correct 



