THE ALUMNI JOURNAL. 



37 



tion of sulphate of iron with some acetic 

 acid. After it is developed, the developer 

 is washed off, fixed with hypophosphite of 

 sodium, dried, varnished and we get the 

 negative. 



Now, the curious part about this wet 

 plate process is that it is slow. The 

 compounds are not very sensitive com- 

 pared with the modern compounds. In 

 the second place it is essential to use it 

 wet. If you took the plate out of the 

 silver bath where you sensitized it and 

 washed off the nitrate of silver adhering 

 to it and put the plate in the camera you 

 would not get a picture. The silver 

 nitrate is essential to the production of 

 the picture. It acts in this way : Where 

 the light has acted upon the sensitive 

 silver compounds and you proceed to 

 develope the picture, when you mix the 

 sulphate of iron and pour the developer 

 upon the plate, as the iron comes in con- 

 tact with the nitrate of silver, with 

 which the plate is wet, it produces 

 metallic silver, which adheres to those 

 parts of the picture which have been 

 acted upon by the light. That seems to 

 be the philosophy, because if you wash 

 the nitrate off you cannot develop a pic- 

 ture upon such a plate. 



Now, this process of photography 

 revolutionized the daguerreotype, revolu- 

 tion! zed photography and the daguerreo- 

 type became obsolete. I think it dis- 

 placed the daguerreotype in three years. 

 This procees was such an advantage — 

 collodion was such a nice substance to 

 work with — that it revolutionized the 

 photography of those days, and the da- 

 guerreotype fell out of existence. 



Now, when you take into considera- 

 tion the time that people had to sit for 

 their pictures — five or six minutes —you 

 can conceive how hard it was to keep still. 

 They had such queer contrivances to 

 keep the head straight, they screwed 

 you up in various positions, and 



this was particularly exasperating where 

 they had to take pictures requiring a 

 good deal of time. Dr. Draper, who 

 took some of these daguerreotypes, and 

 who I believe was the first photographer 

 of these pictures, desired to take a photo 

 of his estimable lady. His studio was 

 in the old University Building in Wash- 

 ington Square. I believe Mrs. Draper 

 had to sit twenty minutes for that pic- 

 ture. In order to produce the best effect . 

 he had a tank made in the top of the 

 laboratory so as to produce a blue light. 

 Mrs. Draper was very patient while he 

 was at work with this, and unfor- 

 tunately, Dr. Col ton tells me, the result 

 was two pictures on the same plate. I 

 should think it would. That was the 

 first effort ever made to take the human 

 face with the daguerreotype. Of course, 

 with all that paraphernalia, with that 

 slowness of action, anything that worked 

 within a minute was considered wonder- 

 ful, and that was practically what hap- 

 pened when Scott Archer discovered col- 

 lodion. 



This wet plate process continued from 

 1 85 1 to 1 87 1, about twenty years. I 

 have the pleasure of showing vou an 

 amateur outfit for this process, used in 

 i860 to take to the Rocky Mountains 

 (exhibiting it). That is an amateur out- 

 fit carried over the Rocky Mountains in 

 i860 to take pictures. Here is the old 

 tank that carried the water. Here are 

 some of the bottles of chemicals, and the 

 way it was managed was this : This was 

 hooked up, on the end of these sticks. 

 This was the black cloth used as the de- 

 veloping room by the operator. Here is 

 a little window with yellow glass to de- 

 velop the pictures. The plates and bro- 

 mide of silver was carried, in these two 

 boxes. That was carried on top of the 

 mule and the boxes on the sides of the 

 mule, so that he had a pretty good 

 mule 



