438 tin. The fragments are intermediate angular, and blunt- edged. It yields easily to the knife. It is brittle. It is easily frangible. It is heavy. Specific gravity, 4.350, Klaproth. 4.785, La Me- the >i'e. It is not magnetic. Chemical Characters. , Before the blowpipe it exhales a sulphureous odour, and melts easily, without being reduced, into a black scoria. It communicates a yellow or green colour to borax. Constituent Parts. Tin, 34 26 50 Copper, - 36 30.00 Iron, 3 12.00 Sulphur, 25 30.50 Earthy Matter, 2 _ 99 100 Klaproth, Beit. Klaproth, Beit. b. ii. s. 230. s. 257.-264. Geognostic and Geographic Situations. It has been hitherto found only in Cornwall, as at St Agnes, Stenna Gwynn, Hiiel Uock, and Iluel Scorier, associated with ores of copper and blende. Observation. It was formerly confounded with Magnetic Pyrites. 2, Tinstone-