DUMAS Jean-Baptiste [Alès, 1800 - Cannes, 1884], French chem - Lot 323

DUMAS Jean-Baptiste [Alès, 1800 - Cannes, 1884], French chemist and politician. Autograph letter signed to Mr. d'Hombres Firmas. Geneva, March 20, 1821; 3 pages in-4° with 3 small sketches in a margin. Magnificent scientific letter on the classification of the blood. "I carried out this research jointly with Mr. Prévost [...] We are working together on a great work of Physiology We are working together on a great work of Physiology of which this memoir forms a chapter that can be considered as a monograph of blood. [...] We found that these so-called globules were flat bodies formed of two quite distinct substances. 1° a small sphere situated in the center, deprived of color, very transparent and of the same diameter in all animals. 2° a blade of red matter arranged in the form of a collar 2° a blade of red material arranged in the form of a collar around this sphere and variable either by the size or by the shape. The name of particle of blood seemed to us suitable to designate this assembly...."