Abstract

In 1674 the natural philosopher and physician Martin Lister published a new method of making glass of antimony for telescopic mirrors, using Derbyshire cawk or barite as a flux. New manuscript evidence reveals that Sir Isaac Newton requested samples of the cawk and antimony from Lister through an intermediary named Nathaniel Johnston. An analysis of Lister’s paper and Johnston’s correspondence and its context reveals insights not only about Newton’s work with telescopic specula but also about his alchemical investigations. Analysing these sources also contributes to our understanding of the nature of correspondence networks in the early ‘scientific revolution’ in England.