[PETIT-RADEL (Philippe)]. Four LAS by Philippe Petit-Radel (1749-1815), surgeon and scientist. - LAS from Philippe Petit-Radel to M. Heunel, S. l. n. d., bifeuillet, 1 written page, format in-16: "Obligés moi, s'il en est encore temps de mettre dans votre envoi deux douzaines du dernier ouvrage sur les maladies véneriennes...". - LAS from Philippe Petit-Radel to M. Agasse, Paris, August 3, 1811, 1 written page, in-12 format. - LAS from Philippe Petit-Radel to Citoyen-Préfet, 11 vendémiaire an 12, 1 written page, format in-12: "[...] vous trouverés ci-joint la note des ouvrages que j'ai publiés...". - LAS from Philippe Petit-Radel to the Secretary of the Académie des Sciences de Turin, letter on Institut Royal de France letterhead, Paris, January 7, 1833, 1 written page, in-4 format. Petit-Radel thanks his appointment as corresponding associate of the Turin Academy: "[...] I shall redouble my zeal in my research into the ancient centuries of the history of a famous region, which has been my homeland for nine years...".