" 



PLAIN DIRECTIONS 



FOR 



OBTAINING PHOTOGRAPHIC PICTURES BY THE 

 CALOTYPE, ENERGIATYPE, AND OTHER PRO- 

 CESSES ON PAPER. 



THE art of Photography, by which, through the agency of light, 

 the most accurate and beautiful representations of objects are 

 obtained, is the fruit of modern science and research. The darken- 

 ing of nitrate of silver under the rays of the sun had indeed been 

 long known, but no attempt was made to apply this fact to the 

 purposes of art until 1802, when Mr. T. Wedgewood published a 

 " Method of Copying Paintings upon Glass, and making Profiles 

 by the Agency of Light upon Nitrate of Silver." That eminent 

 chemist, Sir Humphrey Davy, assisted Mr. Wedgewood in his 

 enquiries ; but being unable to discover any mode of fixing the 

 images obtained, the experiments were abandoned. About 1814, 

 Mr. Niepce, of Chalons sur Marne, turned his attention to this 

 subject; and in 1 827, presented to the Royal Society of London 

 some specimens of pictures produced by the agency of light on 

 glass, copper plated with silver, and highly planished tin : soon after 

 which he entered into partnership with M. Daguerre. The latter 

 gentleman, after repeated, but it would seem fruitless attempts, to 

 prepare a sensitive paper, entered upon those experiments which 

 ended in the discovery of the beautiful process on silver plates which 

 bears his name. In the interval, Mr. Henry Fox Talbot made known 

 the results of his enquiries into the action of light upon salts of 

 silver, in a paper read before the Royal Society in January, 1839, 

 which he followed up in the succeeding month by another, detailing 

 his method of preparing a paper for photographic purposes, and 



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