Colours, humours and material change in late Renaissance chymistry and medicine

Abstract This article explores the notion of colour at the crossroads of humoral medicine and chymistry in late Renaissance Europe. First, it considers the broader context of the traditional analogy between the transmutation of the stone and the formation of humours in medieval alchemy. By highlighting colours as visual markers of material change, alchemical texts drew analogies and metaphors from Galenic medicine to describe the gradual transformation of bodies and their corresponding chromatic change during transmutation. As argued in this paper, such views shifted with the emergence of Paracelsian medicine. This ‘new’ chymical philosophy downplayed the humoral conception of colours in favour of the chymical ‘principles’ and ‘seminal powers’ obtained by distillation. In examining the views of Petrus Severinus, Joseph Du Chesne, and Daniel Sennert, this article aims to appraise their reception of the medical and alchemical tradition on colours, as well as their contribution to a novel yet epistemically ambivalent understanding of colour and sensory properties in the early seventeenth century.