A—CALDRON. B—TANK. C—CROSS-BARS. D—ROPES.
E—LITTLE STONES.
By the third method vitriol is made out of melanteria and sory.
If
the mines give an abundant supply of melanteria and sory, it is better to
reject the chalcítís, and especially the mísy, for from these the vitriol is impure,
particularly from the misy. These materials having been dug and thrown
into the tanks, they are first dissolved with water; then, in order to recover
the pyrites from which copper is not rarely smelted and which forms a sedi
ment at the bottom of the tanks, the solution is transferred to other vats,
which are nine feet wide and three feet deep. Twigs and wood which float
on the surface are lifted out with a broom made of twigs, and afterward all the
sediment settles at the bottom of this vat. The solution is poured into a
rectangular leaden caldron eight feet long, three feet wide, and the same in
depth. In this caldron it is boiled until it becomes thick and viscous, when
it is poured into a launder, through which it runs into another leaden caldron
of the same size as the one described before. When cold, the solution is
drawn off through twelve little launders, out of which it flows into as many
wooden tubs four and a half feet deep and three feet wide. Upon these tubs
are placed perforated crossbars distant from each other from four to six
digits, and from the holes hang thin laths, which reach to the bottom, with
the mines give an abundant supply of melanteria and sory, it is better to
reject the chalcítís, and especially the mísy, for from these the vitriol is impure,
particularly from the misy. These materials having been dug and thrown
into the tanks, they are first dissolved with water; then, in order to recover
the pyrites from which copper is not rarely smelted and which forms a sedi
ment at the bottom of the tanks, the solution is transferred to other vats,
which are nine feet wide and three feet deep. Twigs and wood which float
on the surface are lifted out with a broom made of twigs, and afterward all the
sediment settles at the bottom of this vat. The solution is poured into a
rectangular leaden caldron eight feet long, three feet wide, and the same in
depth. In this caldron it is boiled until it becomes thick and viscous, when
it is poured into a launder, through which it runs into another leaden caldron
of the same size as the one described before. When cold, the solution is
drawn off through twelve little launders, out of which it flows into as many
wooden tubs four and a half feet deep and three feet wide. Upon these tubs
are placed perforated crossbars distant from each other from four to six
digits, and from the holes hang thin laths, which reach to the bottom, with