1been kindled, this kind of ore is
roasted in an enclosed pot, which is stopped
up with lute. A less valuable ore is even burned on a hearth, being placed
upon the charcoal; for we do not make a great expenditure upon metals, if
they are not worth it. However, I will go into fuller details as to all these
methods of preparing ore, both a little later, and in the following Book.
up with lute. A less valuable ore is even burned on a hearth, being placed
upon the charcoal; for we do not make a great expenditure upon metals, if
they are not worth it. However, I will go into fuller details as to all these
methods of preparing ore, both a little later, and in the following Book.
For the present, I have decided to explain those things which mining
people usually call fluxes6 because they are added to ores, not only for
assaying, but also for smelting. Great power is discovered in all these fluxes,
but we do not see the same effects produced in every case; and some are of a
very complicated nature. For when they have been mixed with the ore
and are melted in either the assay or the smelting furnace, some of them,
because they melt easily, to some extent melt the ore; others, because they
either make the ore very hot or penetrate into it, greatly assist the fire in
separating the impurities from the metals, and they also mix the fused part
with the lead, or they partly protect from the fire the ore whose metal contents
would be either consumed in the fire, or carried up with the fumes and fly out
of the furnace; some fluxes absorb the metals. To the first order be
longs lead, whether it be reduced to little granules or resolved into ash by
fire, or red-lead7, or ochre made from lead8, or litharge, or hearth-lead, or
people usually call fluxes6 because they are added to ores, not only for
assaying, but also for smelting. Great power is discovered in all these fluxes,
but we do not see the same effects produced in every case; and some are of a
very complicated nature. For when they have been mixed with the ore
and are melted in either the assay or the smelting furnace, some of them,
because they melt easily, to some extent melt the ore; others, because they
either make the ore very hot or penetrate into it, greatly assist the fire in
separating the impurities from the metals, and they also mix the fused part
with the lead, or they partly protect from the fire the ore whose metal contents
would be either consumed in the fire, or carried up with the fumes and fly out
of the furnace; some fluxes absorb the metals. To the first order be
longs lead, whether it be reduced to little granules or resolved into ash by
fire, or red-lead7, or ochre made from lead8, or litharge, or hearth-lead, or
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