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BOOK VIII
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175
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because
of the dryness that holds the moisture in check and does not allow it
to adhere to the table. It flees from fire with such force that if it
is not given an avenue of escape in the lower part of a vessel it will
attack the upper part and even adhere to the cover of a closed vessel.
Since it contains more air than water, as Aristotle correctly
believed, it is not congealed except through the chemist's art. It is
friendly to gold. While other metals and objects of great mass and
weight float in it, a very small piece of gold sinks. A talent of iron
will float in two talents of quicksilver while one seven-thousandth of
that amount of gold will sink. Since it draws gold into itself it
cleans gold the best, according to Pliny, and removes certain
impurities after numerous shakings in earthenware vessels. The
impurities are removed when the quicksilver is parted from the gold. It
is parted from gold by first pouring it into special skins. It flows
through the skin like sweat leaving the gold behind. The quicksilver
that has adhered to the gold volatilizes when placed over a hot fire.
Quicksilver also adheres readily to the plumbum metals, with
difficulty to silver, with greater difficulty to copper and with the
greatest difficulty to iron. Artisans who gild silver and copper
objects first smear them with quicksilver in a manner known only to
them after which the objects will hold the gold foil with the greatest
tenacity. Artificial cinnabar is made from quicksilver and I shall
explain the method in its proper place. The Moors, after drying the
quicksilver in the sun, place it in basins that are covered with hides
and kept in a cool place. It cannot be stored in just any basin nor in
common vases. The proper container must be made of metal, solid rock or
glass. It escapes from earthenware and wooden vessels.
This
metal offers many uses to the chemist. Physicians use it to cure a
mange the Italians call "French mange" and the French call "Spanish
mange." Dioscorides writes that it is fatal when drunk since it eats
through the vital organs because of its weight. Galen, following
Dioscorides, writes in one place that the heat of the body activates it
to such a point that it kills by corrosion and in another place
considers it among the substances essential to mankind. These are
contradictory views since a very small quantity taken into the body
attacks it violently. In still another place he writes that no one has
actually tested its strength to ascertain if a potion would kill or if
it could destroy the body when placed on the outside. Recently a
depraved wife gave her husband quicksilver and swallowed some herself
but this was ejected from the stomach without any harm. Nevertheless,
having committed a crime, she was punished by law. When mixed with
other substances so that it does not corrode, when taken internally or
rubbed on the skin so that the body heat is able to exert its full
force, it attacks the head and causes excessive discharges, part of
which flows out through the mouth, part settles in the gums and cheeks
and causes them to swell.
When
placed in the proper kind of container by a chemist and placed over a
fire quicksilver will be carried by the heat to the upper part of the
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