Le Daguerréotype.(Analyse de la communication faite à l'Academie par M. Arago).

1839. Paris, Crochard et Comp., 1839. Orig. printed yellow wrappers (no backstrip). In 'Annales de Chimie et de Physique', 2e series, Volume 71, Juillet- issue, pp. 225-352 (entire July-issue offered with orig. wrappers and titlepage to vol. 71). Arago's paper: pp. 313-340. First printing of probably the first (the Juillet issue of Annales) official announcement of Daguerre's invention of the photographic process. The paper offered here preceeded the official report in Comptes Rendues which was published at the end of 1839 (in the July-December issue). The first report of on the discovery was presented to the Royal Academy on January 7, 1839 and delivered in full on August 19, 1839 (and printed in the July-Dec. issue of Comptes Rendues). The paper also preceeded Daguerre's own publication of 1839 "Historique et description du daguerréotypie..."In 1839 Arago took a personal interest in announcing and popularizing the inventions of Niepce and Daguerre, who were awarded government pensions as a result of Arago’s recognition of their inventions’ potential significance."In 1829 Daguerre went into partnership with Niepce, who had managed to produce images by the action of light some three years earlier but had failed to make the process really practical. Daguerre carried on and began to use copper plates on which silver salts were deposited. ight was made to focus upon that and an image was formed. The light portions of the image darkened the salts, while the shadowy portions left them unaffected. The unchanged salt was dissolved away by sodium thiosulfate (a process that had been suggested by John Herschel and a permanent image of sorts was left behind."(Asimov).Together with JEAN CHARLES PELTIER "Mémoire sur la Formation des Tables des Rapports qu'il y entre la Force d'un Courant électrique et la Déviation des aiguilles des multiplicateurs; suivi de Recherches sur la Causes de Pertubation des couples thermo-électriques...", pp. 225-313.