The American annual of photography . Figure i perimenting and finally achieved the desired result in August 19, 1839, he publicly announced and gave the fulldetails of the first photographic process. The French govern-ment awarded him a pension of 6000 francs and a pension of4000 francs to the heir of Niepce. Herewith the facts of the accidental discovery are given. Asilver plate, which had been brightly polished and burnishedfree from scratches, was backed with copper. Then it wassubjected to an apparatus in which it was iodized (Figure i). 172. ??? Clot&sIron Figure 2 Several months
The American annual of photography . Figure i perimenting and finally achieved the desired result in August 19, 1839, he publicly announced and gave the fulldetails of the first photographic process. The French govern-ment awarded him a pension of 6000 francs and a pension of4000 francs to the heir of Niepce. Herewith the facts of the accidental discovery are given. Asilver plate, which had been brightly polished and burnishedfree from scratches, was backed with copper. Then it wassubjected to an apparatus in which it was iodized (Figure i). 172. ??? Clot&sIron Figure 2 Several months were required for the iodine and the silver toreact, forming a thin film of silver iodide. It was one of these iodized and exposed plates that Daguerreone evening placed in his cabinet before retiring. Next morn-ing when he brought forth this plate, he was surprised to findthat the photograph had completely developed during the he investigated, and tried every chemical in hiscabient, which might have produced this result. He triedthem one by one, until he finally used mercury and obtainedthe same result. 173 The explanation of his discovery is as follows: Mercury,which is liquid at ordinary temperature, is also highly vola-tile. When he placed the undeveloped but exposed plate inhis cabinet, the volatile mercury reacted with the silver iodideand developed the latent image into permanent form, whilecommon table salt was used afterward to thoroughly fix this discovery an apparatus for the development otplates wa
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1919
