150 THE RISE AND PROGRESS OF PHOTOGRAPHY. 
with 8 sun full in his face ; the operator gives the final warning 
to be still. The seconds pass—suceee each other—and seem to 
expand into centuries. The sitter (or as he ought now to be 
torture ; his features shrivel up, tears fall from his eyes, perspi- 
ration breaks out from his forehead, he pants for breath, his 
entire body shakes like that of an epileptic who wants to keep 
still, and the eee erere late represents the i image of a pee 
wretch who is undergoing the torture of ordeal by fire 
_ Shortly after its Ae isabiony Goddard added atone to the 
the best of which were those by Professor Petzval, manufactured 
by Voightlander, who became celebrated for his now-called 
- photographic aaaate: These, however, have in their turn been 
Oss, al = Eom er 
While these great pivesada were going on in France our English 
investigators had not been idle, for we find that Mr. Fox Talbot 
had been Sere silently for some time with the silver salts. For 
the carrying out of his particular — he used to prepare his 
paper by i immersing it ina solution of common salt, and when 
soon became dark and useless. He tried to fix them by plunging : 
them into a hot solution of salt, but this only parfially succeeded ; 
and it is to the eminent English astronomer, Herschell, that we 
ri 
hyposulphite of soda. He also introduced many interestin 
rocesses that are out of date now. The chemicals employ 
were the ferricyanide of Potash, ammonia, citrate of 
iron, and the ferro tartrate of silve 
The scientific world had by this sine become oe inter- 
taken by the Daguerreotype, Talbotype, an ocesse 
The negative process on wax r had been clearly demonstrated, 
any anxious experimenters were held th nts 
Pp 
yw withdrawn, as s will be seen by the fcllowing ro ne e 
first is from the Presidents of the Royal Society an nen ae 
= Academy, and appeared in the Limes, ‘August 13¢h, np ee ; a 
