158 Photography — Its History, Position, and Prospects. 



carefully prepared, may be found quite insensible. He claimed 

 a patent right in the use of gallic acid as a most effective sensi- 

 tizing agent, but Sir J. Herschel had already attempted to 

 apply it to that purpose, and Read had actually succeeded in 

 doing so. In 1840, Sir J. Herschel had found that photographic 

 effects might be produced by means of any chemical agent 

 whose constituents are not firmly combined. And, in 1841, 

 Claudet discovered that certain substances possessed the 

 property of imparting rapidity, that is, of diminishing the time 

 required for exposure to the action of light. 



It has been asserted that Watt obtained pictures with both 

 silvered plates and paper ; and specimens of photography on 

 these substances, said to have been produced by him, have 

 been exhibited. 



Attempts were soon made to obtain substitutes for paper, 

 which is exposed to many and serious defects, particularly 

 when used for the production of negatives. M. Niepce de 

 Saint Victor was very successful in this, as he has sinice been 

 in other branches of photography. Like his uncle, the col- 

 league of Daguerre, he was in the army before he became an 

 experimentalist. In 1842, being a lieutenant of dragoons in 

 garrison at Montauban, he amused himself with scientific 

 researches. It happened that the government resolved in that 

 year to change the colour which had hitherto characterized the 

 uniform of the regiments of dragoons, for another. But where 

 was Mareschal Soult to find the money required for this altera- 

 tion ? Hearing of Niepce as a young officer who was likely to 

 carry out his plans with the required economy, he sent for Aim. 

 On arriving in Paris, Niepce showed that a brush dipped in a 

 certain fluid would produce the required transformation. He 

 received five hundred francs for his ingenuity, which saved the 

 government a thousand times as much, and a gracious letter. 

 While in Paris, ho was greatly struck by the photographs 

 which met bis view on every side, and, coming to the con- 

 clusion that there only could he make experiments with 

 full effect, ho managed to have himself transferred to the 

 municipal guard of that city, and established his laboratory in 

 the barrack of .the Faubourg St. Martin. Here he made dis- 

 coveries which have inscribed his name in (lie annals of photo- 

 graphy. In the conflagration of the barrack, after tho flight 

 of Louis Philippe, all his specimens and apparatus perished, 

 but he was soon more favourably circumstanced than ever. 

 The provisional government made him captain of the Republican 



Guard, and, afterwards, the I'hiiperor Napoleon appointed him 



Commandant of the Louvre. In 1847 he presented a memoir 



to the Academy of Sciences on a means of obtaining pictures 

 on glass. Starch was the first substance he employed as a 



