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BOOK X
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215
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mineral is carried to the lid where it forms a black, bluish black, or gray compound which the chemists call sublimate of cadmia. This is even more corrosive than the natural mineral.26 There is a natural relationship between this cadmia and spodos and pompholyx as was noted by Serapio, the Moor. The Greeks did not know it. Each is produced when cadmia, pyrite,
galena, or similar metallic substances are burnt by subterranean fires
or by fires set by miners in underground workings or pits in order to
break the hard rocks. Black, bluish black, and gray spodos are obtained from cadmia; white pompholyx and gray spodos from pyrite; and yellow and gray spodos from galena. The white pompholyx obtained from a copper bearing stone will turn green eventually. Black sooty spodos is found at Aldenberg, Misena. White fluffy pompholyx occurs
in the joints of the rocks of almost all quarries at Hildesheim except
those in sandy rocks and in the summer it is often seen floating in the
air.27 The gray, dark blue and yellow varieties are found in
certain silver mines where the miners break the rock by fire setting.
All are tenuous and therefore light while the white pompholyx (halotrichite) is the lightest of all. All are strong desiccants. That which is produced from cadmia is exceedingly corrosive although it is not especially biting since it is so tenuous.28
If the Aldenberg mineral falls on a sore or any place where the skin is
broken a workman will not feel it particularly although it will eat
away the skin until the bone is laid bare. This is enough concerning
the four genera of mixed substances that contain a metal and also
concerning spodos and pompholyx found in mines.
I
shall now take up the sixth genus, which as I have said, contains a
stone, a metal and a congealed juice. Substances placed in this genus
are distinguished by the juice they contain. The mixture of a stone and
a metal contains either sulphur, bitumen, alum, atramentum sutorium, salt,
soda, or some other congealed juice. The cupriferous, cleavable rock
found in Hesse near Werre Suntel belongs to the first. When burnt it
gives off sulphurous moisture. Sulphur and then silver are smelted from
a similar blackish rock from Kromen, Bohemia. Sulphur is obtained from
pyrite in the Harz forest near Harzgerode and near the Elbe river at
Brambach. Spinus found in the mines of Thrace belongs to the
second species. It is very heavy, as Theophrastus says, and can be
recognized readily when held in the hand. Stones that contain a metal
are heavy while those that contain bitumen are light and one containing
a mixture of the two has an intermediate weight. Having been broken up
and heaped
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meaning
goblin or some malignant force. The cobalt minerals had the appearance
of silver and yet the alchemists and smelters could extract no metal
from them, obtaining instead corrosive and poisonous fumes.
26 This
impure sublimate consisting in part of poisonous arsenious oxide was
known as Huttenrauch. The natural mineral is arsenolite, arsenic oxide.
27 This probably refers to alums and other closely related sulphate minerals.
28 This may refer to goslarite, the hydrous sulphate of zinc.
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