Note 7 — BOOK X.

Distillation, at least in crude form, is very old. Aristotle (Meteorologica, IV.) states that sweet water can be made by evaporating salt-water and condensing the steam. Dioscorides and Pliny both describe the production of mercury by distillation (note 58, p. 432). The Alchemists of the Alexandrian School, from the 1st to the 6th Centuries, mention forms of imperfect apparatus—an ample discussion of which may be found in Kopp, Beiträge zur Geschichte der Chemie, Braunschweig, 1869, p. 217.