Early Theories of Aqueous Mineral Genesis in the Sixteenth Century

Abstract

The generation of minerals is recognised as one of the most important issues of premodern chemical science. While stony minerals and gems were believed to have origins associated with water at least from Hellenic times, the generation of metals was thought to involve the mineral exhalations first proposed by Aristotle. Exhalation theory was coupled with the Sulfur–Mercury view of metal composition by medieval Arab authors, after which it became, in various forms, the principal theory of metallogenesis up to the seventeenth century. From this background, the appearance in the sixteenth century of fully developed theories in which all mineral substances arise from aqueous processes seems quite sudden. I discuss and compare three of the earliest aqueous mineral theories: those of Georgius Agricola, Paracelsus, and Bernard Palissy. The details of these innovative ideas are emphasised, revealing the degree of variety with which aqueous minerallogenesis entered the literature. These theories constituted a break from the traditional exhalation theories, and reflect the influence of observations connected to familiarity with mining operations. However, a role for mineral vapours was kept and expanded upon by subsequent authors who adopted the idea of minerallogenesis through aqueous processes. I thus attempt to demonstrate the versatility and explanatory power with which aqueous minerallogenesis entered the literature.