346 
Tin. 
Internally it is glistening, sometimes shining, and sel- 
dom passes into splendent, and its lustre is metallic. 
Fracture sometimes small and coarsegrained uneven; 
sometimes, but rarely, inclining to small and imperfect 
conchoidal, and imperfect foliated. 
Fragments indeterminately angular, blunt-edged. 
Is semihard, passing into soft. 
Brittle. 
Easily frangible. 
Heavy. 
Specific gravity, 4.350, Klaproth; 4.785, La Metherie, 
Chemical Characters . 
Before the blow-pipe it gives a sulphureous odour, and 
melts easily, without being reduced, into a black scoria^ 
It co^nmunicates a yellow or green colour to borax. 
Constituent Parts . 
Tin 34 
Copper, 36 
Iron, 3 
Sulphur, 35 
Earthy matter, 2 
Klaproth . 100 
Geognostic and Geographic situations y 
It has been hitherto found only at Wheal-rock and St. 
Agnes in Cornwall, where it occurs in a vein about nine 
feet wide, accompanied with copper-pyrites and brown- 
blende, or sulphuret of zinc. 
Observation . 
It was formerly confounded with Magnetic Pyrites. 
