Thumerßone. 273 The proportion of ingredients in the fourmalines of Ceylon, Tyrol, and Brazil, according to Mr. Bergman, and in that of Mount Gothard, in Swiflerland, according to Struvius, is as follovvs: Ceylon. Tyrol. Brazil. St. Gothard. Silex Argill 37 39 40 42 34 39 37>5 3^.5 Calx *5 12 11 1(0 Iron 9 6 5 9 17th Species. Thumerftone *. Shorl Violet de Dauphine, Glafs Shorl of fotne. Its colour is clove brown, often very light, or inclining to red, greenifh, or pearl grey; or in* clining to violet, orblack. Its luftre, 2. Tranfparency of the amorphous, 2.i j of the cryftallized, 3.4. It is found either amorphous or cryftallized \ the amorphous is lamellar, and nearly foliated. The cryftallized forms flat rhomboidal cryftals, whofe angles are truncated. The faces, except where truncated, generally longitudinally ftreaked; the grey are oftcn cellu lar, and the cells filled with the brown variety. The fraflure, minute conchoidal, inclining to the uneven. Fragments, 3. * 1 Bergman, Journ. 1788, p. 55, and 262. 1 Helvet. Magaz. 180. T Its