alloy of gold and lead is obtained which is put into the cupellation furnace.
Two parts of roasted pyrites or cadmia which contain gold, are put with
one part of unroasted, and are smelted together in the third furnace whose
tap-hole is always open, and are made into cakes. When these cakes have
been repeatedly roasted, they are re-smelted in the furnace whose taphole is temporarily closed, or in one of the two others whose tap-holes are
always open. In this manner the lead absorbs the gold, whether pure or
argentiferous or cupriferous, and the alloy is taken to the cupellation
furnace. Pyrites, or other gold ore which is mixed with much material that
is consumed by fire and flies out of the furnace, is melted with stone from
which iron is melted, if this is at hand. Six parts of such pyrites, or of gold
ore reduced to powder and sifted, four of stone from which iron is made, likewise crushed, and three of slaked lime, are mixed together and moistened
with water ; to these are added two and a half parts of the cakes which
contain some copper, together with one and a half parts of slag. A basketful of fragments of the cakes is thrown into the furnace, then the mixture
of other things, and then the slag. Now when the middle part of the
forehearth is filled with the molten material which runs down from the
furnace, the slags are first skimmed off, and then the cakes made of pyrites ;
afterward the alloy of copper, gold and silver, which settles at the bottom,
is taken out. The cakes are gently roasted and re-smelted with lead, and
made into cakes, which are carried to other works. The alloy of copper,
gold, and silver is not roasted, but is re-melted again in a crucible with an
equal portion of lead. Cakes are also made much richer in copper and gold
than those I spoke of. In order that the alloy of gold and silver may be
Historical Note on Gold.—There is ample evidence of gold being used for ornamental
purposes prior to any human record. The occurrence of large quantities of gold in native
form, and the possibility of working it cold, did not necessitate any particular metallurgical
ingenuity. The earliest indications of metallurgical work are, of course, among the
Egyptians, the method of washing being figured as early as the monuments of the IV
Dynasty (prior to 3800 b.c.). There are in the British Museum two stelae of the XII Dynasty
(2400 b.c.) (144 Bay 1 and 145 Bay 6) relating to officers who had to do with gold mining in
Nubia, and upon one there are references to working what appears to be ore. If this be true,
it is the earliest reference to this subject. The Papyrus map (1500 b.c.) of a gold mine, in
the Turin Museum (see note 16, p. 129), probably refers to a quartz mine. Of literary evidences
there is frequent mention of refining gold and passing it through the fire in the Books of Moses,
arts no doubt learned from the Egyptians. As to working gold ore as distinguished from
alluvial, we have nothing very tangible, unless it be the stelae above, until the description of
Egyptian gold mining by Agatharcides (see note 8, p. 279). This geographer, of about the
2nd century b.c., describes very clearly indeed the mining, crushing, and concentration of ore
and the refining of the concentrates in crucibles with lead, salt, and barley bran. We may
mention in passing that Theognis (6th Century b.c.) is often quoted as mentioning the
refining of gold with lead, but we do not believe that the passage in question (hoi) :
• " But having been put to the test and being rubbed beside (or against) lead as being refined
" gold, you will be fair," etc. ; or much the same statement again (418) will stand much
metallurgical interpretation. In any event, the myriads of metaphorical references to fining
and purity of gold in the earliest shreds of literature do not carry us much further than do those
of Shakespeare or Milton. Vitruvius and Pliny mention the recovery or refining of gold with
mercury (see note 12, p. 297 on Amalgamation) ; and it appears to us that gold was parted
from silver by cémentation with salt prior to the Christian era. We first find mention of parting
with sulphur in the 12th century, with nitric acid prior to the 14th century, by antimony
sulphide prior to the 15th century, and by cementation with nitre by Agricola. (See historical
note on parting gold and silver, p. 458.) The first mention of parting gold from copper occurs
in the early 16th century (see note 24, p. 462). The first comprehensive description of gold
metallurgy in all its branches is in De Re Metallica.
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