64-8 TUNGSTEN, OR SCHEELIUIVf. Constituent Karts. SehlakenwaJd. " Cornwall, 75.25 Acid of Tungsten, 65 77.71 Limc > - 31 17.50 IS. 70 Silica > - 4 3.00 1.56 Oxide of Iron, - — j ^5 Oxide of Manganese, — 0 75 100 98.35 97.45 Schecle, in n. Abhand. Klaproth. Beit. b. iii. d. Schwd. Akad. s . 47. &. 51. 1781, 2, 89. Geognostic Situation. It occurs along with tinstone, magnetic ironstone, and brown ironstone. In the tinstone repositories it is associa ted with wolfram, quartz, mica, fluor-spar, steatite, &c. Geographic Situation. It occurs along with wolfram and tinstone, &.c. in Cornwall: in Sweden, in a bed of magnetic ironstone; in Bohemia and Saxony. ✓ Observation. It is distinguished from the white varieties of tinstone, Y its shape, intensity, and kind of lustre, hardness, greater weight, and its becoming yellow when thrown into nitric acid ; from while lead-ore, by not effervescing with acids, and by not being blackened by an alkaline sulphuret; from heavy. S p ar , by its greater weight, and b) the yellow colour it assumes when thrown into nitric acid. 2. It is named Tungsten, which signifies heavy stone from its great specific gravity. 2. Wolfram-