[ah lem'bik] a piece of equipment
essential to the distillation process
Distillation is one of the
oldest chemical processes known, having been
developed by the Alexandrian alchemists between
100 and 900 A.D. The process was refined by the
Persians, who were particularly noted for their
use of distillation to produce essential oils and
perfume. By the Middle Ages it was in use for the
preparation of strong acids and for making
alcoholic drinks. In the late nineteenth century,
the process was developed on an industrial scale
for the distillation of petroleum and is still an
important technique in the chemical industry.
alembic itself has remained virtually unchanged
to this day. The liquid to be distilled is heated
in a lower vessel and the resulting vapor
condenses on the inside of the dome shape of the
upper vessel, the alembic. The condensed vapor
runs down into the internal gutter and out
through the spout into a collecting vessel.
At left is a third-century A.D.
illustration of alchemical distillation apparatus
showing two alembics. At right is a glass alembic
that dates from tenth- to twelfth-century Islam;
it is on display at the National Museum of
Science and Industry in London, England.