TIN. 
529 
brownish or reddish appearance, which pursuing its 
course through decomposed granite, may often be 
mistaken for mica. Again : tin is not, like most 
other metals, to be found in a multitude of different 
places, and covering a great extent of surface, but 
is confined to particular situations, and included 
within a moderate space. The ore is almost always 
found in granite, or in slate immediately in its neigh- 
bourhood, and which is generally decomposed and 
reduced to a black sand. 
Tin is almost confined to Europe , and is but 
sparingly dispersed even in this quarter of the 
world. In the vast peninsula of Malacca, and in 
the island of Banca, in the East Indies, we hear of 
tin-mines ; but most of the extensive countries in 
that region of the globe, as well as the dry and 
sandy continent of Africa, are totally destitute of 
this metal. 
England, above all other countries, can boast the 
richest tin-mines. Those of Cornwall have been 
worked from time immemorial, and still continue to 
yield vast quantities of ore. The veins of mineral 
either run in slate or granite. Those which are 
found in the granite are ofless extent, and diminish 
in size as they increase in depth, while the veins 
which traverse the slate preserve nearly the same 
magnitude for several hundred yards. Among the 
mines of tin which this country produces, those of 
Huel-cock and Penzance are remarkable for having 
their veins run under the sea. The mine of Huel- 
cock, in the parish of St. Just, is worked to the 
2 M 
VOL. in. 
