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424 METALS—THE NOBLER.
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transmitted by them to Egypt, in baskets made of Palm leaves).
David
Copperfield resolutely studied the art, and practice of stenography, so
as to eke out his income when it was yet narrow. His friend Traddles
would deliver the Parliamentary debate night after night, for
Copper-field to follow as a shorthand reporter. " Often, and often we
pursued these Debates until the clock pointed to midnight, and the
candles were burning down." " The result of so much good practice was
that by and by I began to keep pace with Traddles pretty well, and
should have been quite triumphant if I had had the least idea what my
notes were about. But, as to reading them after I had got them, I might
as well have copied the Chinese inscriptions on an immense collection
of tea-chests, or the golden characters on all the great red, and green
bottles in the chemists' shops."
In
testing bread which is suspected of containing a minute quantity of
copper, a zinc plate will serve to detect this ; all that is necessary
is to acidify the bread with dilute pure sulphuric acid, and leave the
zinc therein. The copper thus deposited on the zinc plate may be
scraped off, dissolved, and tested in other ways. A dilute solution of
common salt attacks copper with considerable rapidity; and thus, when
pickles have been thoughtlessly boiled in badly-tinned copper vessels,
or if a copper coin has been fraudulently placed in the vinegar so as
to impart a fine green colour to the pickles, then a zinc, or iron
plate will readily separate the copper, if this plate be digested for
some time together with the pickles. Workers in copper suffer from
severe abdominal colic, (with remissions) ; to relieve which the
workman bends himself double. This copper colic differs
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