The following oroid or imitation gold is sometimes sold for the
genuine article which it closely resembles. Pure copper, 100 parts by
weight, is melted in a crucible, and then 6 parts of magnesia, 3.6 of
sal-ammoniac, 1.8 of quicklime and 9. of tartar are added separately
and gradually in the form of powder. The whole is then stirred for
about half an hour, and 17 parts of zinc or tin in small grains are
thrown in and thoroughly mixed. The [Transcriber's Note: The original
text reads 'cruicible'] crucible is now covered and the mixture kept
melted for half an hour longer, when it is skimmed and poured out.
Any imitation of gold may be detected by its weight, which is not
one-half of what it should be, and by its dissolving in nitric acid
while pure gold is untouched.