JOURNAL A^D PROCEEDINGS 



A little later Talbot read a paper before the Royal Society with de- 

 tails of his process. Talbot refers, in this paper, to Wedgwood 

 and Davy's work. He improved on their results in two particu- 

 lars : he obtained greater sensitiveness, by coating his paper first 

 with a solution of common salt, then with a nitrate of silver, thus 

 producing silver chloride within the fibres of the paper, in the 

 presence of an excess of the nitrate ; and he used with partial suc- 

 cess, potassium iodide and also salt solution as fixing agents. 



Talbot's first process — the " Photogenic Drawing " — was thus 

 what we call a " printing-out " process for producing by contact in 

 the same manner that Wedgwood had done — or in the camera, 

 which Wedgwood did not do, although he recognized the possi- 

 bility. 



This application of the development principle to his process 

 was an immense advantage, and the calotype paper could be made 

 rapid enough for landscape and portrait photography. The nega- 

 tives were printed on his original "photogenic" paper, and the 

 whole process was such that in 1844 Talbot issued the book of ac- 

 tual photographic views, entitled "The Pencil of Nature." In 

 the following year he published a collection of 23 views under the 

 title "Sun Pictures in Scotland." 



Talbot was an indefatigable patentee. He patented the wax- 

 ing of paper prints to make them more transparent ; he patented 

 the use of a colored backing paper to improve the appearance of 

 transparent prints, and he patented a hot solution of hypo for 

 fixing. 



It is to Sir John Hershall that we owe absolutely the hypo 

 fixation which was the actual consummation of all the photographic 

 processes heretofore mentioned. The first scientific paper of Her- 

 shall which possesses photographic interest was written some 20 

 years before Talbot and Dagurre gave separately to the world dis- 

 tinct photographic processes. It was entitled, " On the Hypo- 

 sulphurous Acids and Its Compounds." In one passage he states 

 that muriate of silver newly precipitated dissolves in this salt when 

 in a somewhat concentrated solution in large quantities, and almost 



