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LAPIS LYDIUS.
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155
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(containing
copper), of the second quality ; but if black (betraying the presenco
of lead), it was pronounced base. Pliny exposes an ingenious fraud of
the silversmiths intended to baffle this test. They kept the
chafing-dish beforehand steeped in urine, the salts of which, when the
iron was heated, fixed upon the filings assayed, and, whitening them
for a time, so enabled the piece to pass muster for fine standard.
Another and more ready test was to breathe upon the polished surface,
the more quickly the breath dispersed, the better the quality of the
plate. As the silver coin even in Pliny's age was falling rapidly in
its standard, we may suspect that the plate also was of a quality more
or less debased, according to the honesty of the silversmith.
It is a curious fact that the Chinese Tutenague or
" white copper " (of late years so largely manufactured here with the
name of German silver) had already, under the Ptolemies, found its way
to Europe as a substitute for the precious metal. Crinagoras sends to a
friend for a birthday present, " a copper flaggon (olpe) exactly resembling silver, an Indian work," together with a neat epigram. (Anth. vi. 261.)
The
famed " Corinthian Brass " may be classed indifferently amongst the
ancient alloys of gold or of silver. Pliny describes three qualities of
this composite metal, which was an alloy of gold, silver, and copper.
In fact, it was much the same as what our jewellers dignify with the
name of gold, and employ for all articles not Hall-marked for 18 carats
fine. The first quality was yellow-coloured, in which the gold
preponderated ; the second resembled silver, that metal constituting
the greater quantum of its mass ; the third contained all three in
equal proportions. Such alloys would all now pass for gold, and indeed
the first is better than our 12-carat gold, and the third equal
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