RED VITRIOL, OR SULPHATE OF COBALT. 347 Genus IV.—Salts of Cobalt. This Genus contains one species, viz. Red Vitriol or Sulphate of Cobalt. * Red Vitriol or Sulphate of Cobalt. Kobaltvitriol, Werner. Kobaltvitriol, Kopp, in Leonhard's Taschcnbuch, b. i. s. 111. Id Leonhard, Tabel. s. 4.5. Id. Karsten, Tabel. s. 56. Id. Lenz, b. ii. s. 1003.—Ked Vitriol, Aikin, p. 250. External Characters. Its colour is flesh-red, inclining to rose-red. It occurs coralloidal, stalactitic, also in crusts. The surface is rough and longitudinally furrowed. It is dull, and seldom shining on the surfaces of the distinct concretions, and the lustre is pearly. The fracture is earthy. The fragments are blunt-edged. It occurs in granular distinct concretions. It is opaque. It affords a yellowish-white streak. It is easily friable, and brittle. It is light. It tastes styptic. Chemical Characters. Its solution affords, with carbonate of potash, a pale bluish precipitate, which tinges borax of a pure blue co lour. Constituent