A group of three scarce pieces by notable French scientists, includes: PHILIPPE RICORD, famed venereologist and the personal assistant of Napoléon III, he proved that syphilis and gonorrhea are two distinct diseases. A.D.S. 2pp. 8vo., Feb. 22, 1854, a prescription detailing a three-month course of treatment for syphilis, in French on a blue sheet. Toned folds, very good; with JEAN-ANTOINE CHAPTAL, French chemist and Minister of the Interior, he applied the discoveries of chemistry to industry. The process of adding sugar to unfermented wine in order to increase the final alcohol level is known as "chaptalization" after him. A.L.S. 1p. 4to., Paris, May 23, 1818, to the inspector of Customs at Cherbourg, in part: "...I am having the water and salt my wife brought analyzed and I'll send you the results...The Minister is supporting me, and intriguing; presumably I'll be named President of one of the Colleges...". Together with BERNARD DE LACEPEDE, French naturalist and writer. Partly-printed D.S. 1p. legal folio, Paris, Feb. 9, 1807, to Henri Clarke, Minister of War concerning a gentleman Turenne's admission to the Legion of Honor. Three pieces, very good.