536 
TIN. 
duced by the fermentation of barley-meal. After 
this process they are well scoured, till the whole 
surface becomes clean and bright. They are then 
dipped into an iron pot filled with melted tin, whose 
surface is covered either with suet, fat, or pitch. 
When the plates are drawn out, both their surfaces 
are completely coated with the metal, and in this 
state they compose a very clean and useful material 
for many of the common purposes of life. 
In Cornwall, the tin, after being smelted from the 
ore, is poured into quadrangular moulds of stone, 
containing about three hundred and twenty pounds 
weight of metal, and it is then called block-tin. The 
officers appointed by the Duke of Cornwall assay 
it, by taking a piece of the under corners of each 
block ; and, if found pure, it is stamped with the 
seal of the duchy. 
