368 
Tin. 
considering one of the uses to which this sort of pewter is 
applied ; for acid wines will readily corrode the lead of 
the Raggons, in which they are measured, into sugar of 
lead ; this danger is not so great with us, where wine is 
seldom sold by the measure, as it is in other countries 
where it is generally sold so, and their wine measures con- 
tain, probably, more lead than ours do. Our English 
pewterers have at all times made a mystery of their art, 
and their caution was formerly so much encouraged by 
the legislature, that an act of parliament was passed, ren- 
dering it unlawful for any master pewterer to take an ap- 
prentice, or to employ a journeyman who was a foreigner. 
In the present improved state of chemistry, this caution 
is useless ; since any one tolerably skilled in that science, 
would be able to discover the quality, and quantity of the 
metallic substances, used in any particular sort of pewter ; 
and it is not only useless now, but one would have 
thought it must have been always so ; whilst tin, the prin- 
cipal ingredient, was found in no part of Europe in so 
pure a state, nor in so great plenty as in England. 
Borlase and Pryce> who have written so minutely on 
the method of preparing the tin in Cornwall , are both of 
them silent, as to any operation the tin undergoes subsequent 
to its coinage ; nor do they say any thing of its being 
mixed with other metallic substances previous to its coim 
age ; but assure us, that the tin, as it Rows from the ore, 
is laded into troughs, each of which contains about three 
hundred pounds weight of metal, called slabs, blocks, or 
pieces of tin, in which size and form it is sold in every 
market in Europe. Foreigners, however, in general as- 
sert, that our tin as exported is a mixed metal ; and the 
French Encyclopedists in particular (article etain) inform 
us, on the authority of Mr, Rouelle , that the virgin tin is 
aeain melted and cast into iron moulds of half a foot in 
thickness ; that the metal is cooled very slowly ; that 
