HAMILTON SCIENTIFIC ASSOCIATION. 79 



In 1826 comniunication between Dagitrre and Niepce led to the 

 exchange of methods then emplo3^ed, and Dagurre having the de- 

 tails of the latter's methods, investigated the process and continued 

 the experiments along the lines thus mutually obtained, and soon 

 made man}^ modifications. After the death of Niepce, Dagurre 

 abandoned these experiments and resolutely worked along with his 

 own. lyater it was recorded that a partnership was formed between 

 Dagurre and a son of Niepce and efforts were made to float a com- 

 pany to take over and develop the process in consideration of 200,- 

 000 marks. In 1838 Dagurre decided to appeal to the government 

 for aid and succeeded in interesting Arago, the celebrated scientist 

 and astronomer, whose endorsation was sufificient, and the govern- 

 ment awarded pensions to the partners — -4,000 francs to Niepce and 

 6,000 francs to Dagnrre — in exchange for the secrets of their pho- 

 tographic process, and the details of this process, before secret, were 

 laid before the Academy of Science on Aug. 19th, the new art being 

 christened " The Dagurreotype," and the first photographic pro- 

 cess was a reality. 



The process was based upon the use of a highly-polished sur- 

 face of metallic silver, which had been exposed to the vapors of 

 iodine. An extremely thin film was formed on the plate, the 

 iodised plate was exposed in the camera, but no image was seen 

 until the developer was applied, the developer being vapor of mer" 

 cury, often called quicksilver. After removal from the camera the 

 plate was placed face downwards in the upper part of a light tight 

 box, in the lower part of which the mercury vapor was generated 

 by heating the liquid metal with a spirit lamp. 



William Henry Fox-Talbot was, we learn, a country gentle- 

 man living at an ancient residence — Lacock Abbey, in Wiltshire — 

 wdiich it is said his familj' inhabited since the sixteenth century. 

 He was educated at Harrow and Cambridge, and was for two years 

 a member of the House of Commons. In 1828 he is said to have 

 settled down and devoted himself entirely to scientific pursuits at 

 the Abbey at Wiltshire. On Jan. 25, 1839, about one month 

 after the publication of, Dagurre's process, some of Talbot's photo- 

 genic drawings were shown to the members of the Royal Institute. 



