An aludel is a subliming pot used in alchemy and medieval chemistry. The term refers to a range of earthen tubes, or pots without bottoms, fitted one over another, and diminishing as they advance towards the top. The lowest is adapted to a pot, placed in a furnace, wherein the matter to be sublimed is placed. At the top is a head to retain the flowers, or condensation, which ascends. An aludel was used as a condenser in the sublimation process and thus came to signify the end-stages of transformation and the symbol of creation. Also called the Hermetic Vase, the Philosopher's Egg, and the Vase of the Philosophy.
This article incorporates text from a publication now in the public domain: Chambers, Ephraim, ed. (1728). "article name needed". Cyclopaedia, or an Universal Dictionary of Arts and Sciences (first ed.). James and John Knapton, et al.