1silver,
combined with a certain portion of lead, into the cupel, in which way
the assay is rendered erroneous. Then take the beads out of the cupel and
clean them of dross. If neither depresses the pan of the balance in which it
is placed, but their weight is equal, the assay has been free from error; but
if one bead depresses its pan, then there is an error, for which reason the
assay must be repeated. If the bes of coin contains but seven unciae of
pure silver it is because the King, or Prince, or the State who coins the money,
has taken one uncia, which he keeps partly for profit and partly for the
expense of coining, he having added copper to the silver. Of all these
matters I have written extensively in my book De Precio Metallorum et
Monetís.
the assay is rendered erroneous. Then take the beads out of the cupel and
clean them of dross. If neither depresses the pan of the balance in which it
is placed, but their weight is equal, the assay has been free from error; but
if one bead depresses its pan, then there is an error, for which reason the
assay must be repeated. If the bes of coin contains but seven unciae of
pure silver it is because the King, or Prince, or the State who coins the money,
has taken one uncia, which he keeps partly for profit and partly for the
expense of coining, he having added copper to the silver. Of all these
matters I have written extensively in my book De Precio Metallorum et
Monetís.
We assay gold coins in various ways.
If there is copper mixed with
the gold, we melt them by fire in the same way as silver coins; if there is
silver mixed with the gold, they are separated by the strongest aqua valens;
if there is copper and silver mixed with the gold, then in the first place, after
the addition of lead, they are heated in the cupel until the fire consumes the
copper and the lead, and afterward the gold is parted from the silver.
the gold, we melt them by fire in the same way as silver coins; if there is
silver mixed with the gold, they are separated by the strongest aqua valens;
if there is copper and silver mixed with the gold, then in the first place, after
the addition of lead, they are heated in the cupel until the fire consumes the
copper and the lead, and afterward the gold is parted from the silver.
It remains to speak of the touchstone37 with which gold and silver are
tested, and which was also used by the Ancients. For although the assay made
by fire is more certain, still, since we often have no furnace, nor muffle, nor
crucibles, or some delay must be occasioned in using them, we can always
rub gold or silver on the touchstone, which we can have in readiness.
Further, when gold coins are assayed in the fire, of what use are they after
ward? A touchstone must be selected which is thoroughly black and free
of sulphur, for the blacker it is and the more devoid of sulphur, the better it
tested, and which was also used by the Ancients. For although the assay made
by fire is more certain, still, since we often have no furnace, nor muffle, nor
crucibles, or some delay must be occasioned in using them, we can always
rub gold or silver on the touchstone, which we can have in readiness.
Further, when gold coins are assayed in the fire, of what use are they after
ward? A touchstone must be selected which is thoroughly black and free
of sulphur, for the blacker it is and the more devoid of sulphur, the better it