Properties and Classification of Mercury between Natural Philosophy, Medicine, and Alchemy

This paper presents a survey of the different ideas and practices that ancient natural philosophers, physicians, and alchemists developed with reference to mercury (or quicksilver) and cinnabar, its natural ore. Three different sections respectively analyse (i) how these ingredients were described and classified within the Aristotelian tradition ; (ii) the role they played in the early phases of Graeco-Egyptian alchemy ; and (iii) their uses in ancient pharmacology. By taking into account a wide array of different writings (e.g. Aristotle’s Meteorology, Theophrastus’s On Stones, Zosimus’ alchemical treatises and their Syriac tradition, Dioscorides, and Galen), it has been possible to circumscribe sets of questions that the ancients addressed with regard to mercury : its nature, its relation to cinnabar, its classification, and its toxicity. Moreover, experts in different technai described similar procedures for manipulating mercury and cinnabar. These shared technical skills represent an important fil rouge that allowed us to cross the boundaries separating different fields, in order to reconstruct how these ingredients were used and conceptualized within different systems and areas of expertise