Nehemiah Grew, Saline Chymistry of Plants,  Anatomy of Plants (London, 1680) Image(s) courtesy History of Science Collections, University of Oklahoma Libraries; copyright the Board of Regents of the University of Oklahoma
Project (2014-2015)

The Saline Chymistry of Color In Seventeenth-Century English Natural History

Before Newton’s seminal work on the spectrum, seventeenth-century English natural philosophers such as Robert Boyle, Robert Hooke, Nehemiah Grew, and Robert Plot attributed the phenomenon of color in the natural world to salts and saline chymistry. They rejected Aristotelian ideas that color was related to the object’s hot and cold qualities, positing instead that saline principles not only governed principles of matter in the Paracelsian tria prima, but color and color changes in flora, fauna, and minerals as well. These natural philosophers also incorporated theories concerning what we would now call litmus tests and the mixing of artists' pigments into their work. This project also characterized to what extent chymistry was a basic analytical tool for seventeenth-century English natural historians.