of
execution its intrinsic purity, was issued, though sparingly, within my
own recollection. No piece of equal importance with this has ever heen
minted as a current coin since the date of the Ptolemaic
octodrachms. For the new-stamped " Kingdom of Italy," the French
standard of one-tenth alloy (for both metals) has been adopted ; and
the same appears to be now uniformly employed in all the mints of the
Continent, and likewise of America.
The refining and assaying of
gold form the natural sequence to this notice of the " standard of
purity." We have already learnt from Agatharchides' details how the old
Egyptians refined the gold they obtained by quartz-crushing. This
process, however, would only separate the baser metals, not the silver of
the native alloy. How the Greeks and Romans subsequently contrived to
obtain it so absolutely pure, still remains a problem. Unfortunately
our grand authority Pliny fails us here, giving only a few incidental
and scattered hints. Speaking of misy (crude arsenic), he
alludes to its use in this process : " hoc admis-cent qui aurum
purgant." Arsenic still enters into the composition of gold-solder to
make it more fusible. In another place he notes that gold was refined
by melting it along with lead, observing also elsewhere that alum
serves the same purpose equally with lead. Again (xxiii, 22), he
mentions the common employment of quicksilver for the same object, as
the most effectual process of all, the pounded ore being immersed in
the fluid, and shaken for a long time in an earthen pot, by which means
" the gold was forced to vomit up all its impurities." To separate the
quicksilver, the amalgam was put in a leather bag, when by pressure the
former oozed through the pores of the leather, leaving the gold behind pure. And, in fact, this amalgamation would not take up the silver. Penning is now effected by quartation, an operation getting its name
