In 1718 Étienne-François Geoffroy (1672-1731) presented in Paris a "table of affinities" that, by adapting Isaac Newton's (1642-1727) laws of attraction to the microscopic world, effectively and concisely showed the relationships between different substances. Geoffroy also introduced a new method of experimental analysis, based on exposing a number of minerals to the heat generated by a powerful burning lens. With this method, adopted throughout Europe for over a century, the French chemist hoped to reveal the behaviour of microscopic particles.
Inv. 2545, 2710/bis
Benedetto Bregans (lens), Francesco Spighi, Gaspero Mazzeranghi (mount), Lens: Dresden / Mount: Florence, Lens: 1690 / Mount: 1767
Inv. 1899
Franz Huber Hoefer [attr.], ca. 1766