Islamic alembic apparatus, 10th-12th century.
© Science Museum / Science & Society Picture Library
These examples are among the oldest to survive from the West or Near East. The alembic is an esential piece of distillation apparatus used by early chemists. The liquid to be distilled is heated in a lower vesel and the resulting vapour condenses on the inside of the dome shape of an upper vesel, the alembic. The condensed vapour runs down into the internal gutter and out through the spout or delivery tube, into a collecting vesel. The traditional distillation skills were developed by the Alexandria chemists and elaborated in contemporary works of art in AD 100-900. Persian chemists also used distillation to make esential oils and perfumes. Distillation apparatus remains esentially the same today.