Aludel , Ar. uthāl , refers to an apparatus used in alchemy for the sublimation (Ar. taṣʿīd , Lat. sublimatio ) of substances such as mercury, sulphur, and others. The etymology of the term is uncertain. It may derive from the Greek αἰθάλη, "vapour" (see Lippmann and Brockelmann), or-much less likely-it may be a variant of īthāl , pl. of athla , "apparatus" (Dozy, Glossaire ); the Latin terms aludel, aludellum , and alutel correspond to the Arabic al-uthāl . The device is made up of two parts: a glass or earthenware vessel used to contain