James Smithson on the Calamines: Chemical Combination in Crystals

The three mineral species that constitute the common "calamines," or non-sulphurous ores of zinc, were first definitively identified in 1803 by the British chemist and mineralogist James Smithson. The present article proposes a close exegesis of Smithson's argument, which has not previously been studied in any detail. His reasoning integrated chemical, natural historical, and crystallographic considerations, and illustrates important features of the practice of mineral chemistry at this time. Whereas zinc ore was an essential component of the rapidly expanding brass industry, the context for Smithson's work was not commercial, but rather that of mineral collecting and natural history. Appreciating this fact, and the role of crystallography within this setting, helps to shed light on the interesting theoretical speculations about chemical combination that he included in the paper. Smithson's ideas about chemical combination were informed by a structural way of thinking about materials, and his argument illustrates some of the ways that crystallog-raphy influenced chemistry in this period.