Post Lot Text
First edition. Foucault's doctoral thesis on the speed of light, proving that light travels faster in air than in water, an important argument in favour of the wave theory of light. He gives a detailed account of his experiment and illustrates the apparatus. Presentation copy, inscribed by the author to Hofmann, presumably August Wilhelm von Hofmann (1818-1892, ennobled 1888), chemist, director of the Royal College of Chemistry in London, later professor of chemistry at Berlin, author of the much translated text book, An Introduction to Modern Chemistry.