In the foregoing chapters every thing has been included which appeared necessary to the complete illustration of the history of the very beautiful art of Photography. It may appear to many that the manipulatory details included in this division should have been reserved for that which is more strictly technical. The difficulty of doing this without repeating in an unnecessary manner has led me to adopt what I consider to be the clearer course. THE use of paper as the material upon which the coating that is to undergo a chemical change by exposure to solar radiations should be spread, claims our earliest attention on several accounts. Wedgwood and Davy employed paper and white leather in their earliest experiments; and Mr. Talbot's results, obtained also on paper, claim priority, as far as publication is concerned, over any other photographic process. For a long time the employment of paper was confined to our own country, our continental neighbours devoting their inquiries to the processes and physical phenomena connected with the use of the metallic plates constituting the tablets employed by Daguerre; but now they use the paper and glass processes in preference. Notwithstanding the statements which have been too often repeated, to the effect that the practice of photography is exceedingly easy, that the manipulatory details of preparation present no difficulties, and that little more is necessary than to place a paper in a camera obscura, obtain a picture, and take it out |