Mr, William Phillips o7i the OxydofTin. 341 



The oxyd of tin sometimes occurs in form and appearance very- 

 similar to the hematitic iron ore, from which it is easily dis- 

 tinguished by its superior weight. In this state it is mostly in 

 fragments, either straight or diverging, wedge shaped or splintery, 

 rarely rounded and reniform ; those fragments of which the fracture 

 is -fibrous, have a silky lustre ; its colour is brown of different 

 shades, passing into brownish-yellow, which are ranged in alternate 

 bands ; it gives a shining yellowish-brown streak, and is opaque, 

 hard, brittle, and easily frangible ; its spec. grav. is 6.45. This 

 mineral from its occasional resemblance to wood, has obtained the 

 name of wood tin, and is the Kornisches zinnerz of Werner, the 

 Etain oxyde concretionne of Haliy. Before the blowpipe it 

 becomes brownish-red and decrepitates, but is not fused or reduced 

 to a metallic state : when strongly heated in a charcoal crucible, it 

 affords, according to Klaproth, 73 per cent, of reguline tin. It has 

 hitherto been found only in Cornwall, in the parishes of St. Columb, 

 St. Roach and St. Dennis, in alluvial beds accompanied by stream 

 tin ; it is rare, and occurs only in small pieces.* 



Klaproth mentions " a kind of wood tin, from Maddern in 

 Cornwall. This is only found in small separate hemispheres, of 

 the size of a divided shot. The surface is smooth and brown, but 

 the inside or nucleus is of a light brown and of a whitish-yellow 

 colour, and slightly radiated. These stalactitical hemispheres, 

 which, as one may see, have been fixed to other bodies, are similar 

 to the small spherical protuberances of wood tin, except that the 

 latter are not so hemispherical, but flatter. "f This substance, I do 

 not remember to have seen in the form above described, but some 

 rounded portions of tin were given to me by a Cornish gentleman 



* Aikin Chim, Diet. art. Tin. + Klaproth on Fossils of Cornwall, p. 21. 



