aludel

Century Dictionary and Cyclopedia

1. n. In chem., a name given to one of a number of pearshaped glasses or earthen pots, used in sublimation, resembling somewhat the ancient alembic, and open at both ends so that they can be fitted together in a series. The name has also been given to any prolonged chimney or tube of glass or earthenware consisting of more than one piece.
2. n. In modern times it has been applied almost exclusively to the thin earthen condensers used in the collection of mercury at the reduction-works at Almadén, Spain.

Wiktionary

1. n. a pear-shaped pot with an opening at each end, formerly used for sublimation.

GNU Webster's 1913

1. n. One of the pear-shaped pots open at both ends, and so formed as to be fitted together, the neck of one into the bottom of another in succession; -- used in the process of sublimation.