ed with tin ore. The ore got from different
mines, he said, differed in quality, as well as in the percentage of tin
which it contained. Some had much iron mixed with it, in spite of all
the washings it had undergone; some had a little copper and other
substances; while some was very pure. By mixing the tin of different
mines, better metal could be procured than by simply smelting the
produce of each mine separately. Pointing to one of the bins, about
three yards square, he told them it contained tin worth 1,000 pounds.
There was a large quantity of black sand in one of the bins, which, the
agent said, was got by the process of "streaming." It is the richest
and best kind of tin ore, and used to be procured in large quantities in
Cornwall--especially in ancient times--being found near the surface,
but, as a matter of course, not much of that is to be found now, the
land having been turned over three times in search of it. This black
sand is now imported in large quantities from Singapore.

The agent then conducted his visitors to the testing-house, where he
showed them the process of testing the various qualities of tin ore
offered, to the House for sale. First he weighed out twenty parts of
the ore, which, as we have said, resembled snuff. This, he remarked,
contained about five-sixths of pure tin, the remaining one-sixth being
dross. He mixed it with four parts of fine coal dust, or culm, and
added a little borax--these last ingredients being intended to expedite
the smelting process. This compound was put into a crucible, and
subjected to the intense heat of a small furnace for about twenty
minutes. At the end of that time, the agent seized the crucible with a
pair of tongs, poured the metal into an iron mould, and threw away the
dross. The little mass of tin thus produced was about four inches long,
by half an inch broad, and of a dull bluish-grey colour. It was then
put into an iron ladle and melted, as one would melt lead when about to
cast bullets, but it was particularly noteworthy here, that a very
slight heat was required. To extract the metal from the tin ore, a
fierce heat, long applied, was necessary, but a slight heat, continued
for a few minutes, sufficed to melt the metal. This remelted metal was
poured into a stone mould, where it lay like a bright little pool of
liquid silver. In a few seconds it solidified, retaining its clear
purity in all its parts.

"That," said the agent, "is tin