186 ANNUAL OF SCIENTIFIC DISCOVERY. 



of light allowed to pass through it for a time ; there results a double 

 picture on the lower negative, one fainter than the other. It is known, 

 moreover, to the more scientific class of photographers, that if the 

 lens in the camera is imperfectly curved at the surfaces, spots of 

 cloudy light may appear in the photograph, having a semi-ghostly sort 

 of effect. London Photographic Jouni'il. 



Photography and Physiology. The following communication, which 

 appeared in the London Journal of Photography, Oct. 28, 1864, is 

 vouched for by the Editor as entirely reliable : " Some time since my 

 wife was engaged preparing albumen paper in the silver-bath, and in a 

 moment of abstraction pressed two of her fingers on her forehead, 

 being at the time about to add another ' olive branch ' to the family. 

 Soon after the birth of the baby we were surprised and annoyed at 

 noticing that the child, when in a strong light, exhibited two distinct 

 impressions similar to silver stains before fixing ; and the strangest 

 part of the matter is that these disappear as night comes on and reap- 

 pear as daylight arrives. 



" These stains, although at present serving as a sort of actinometer to 

 me, will prove a sad disfigurement to my daughter's appearance in 

 daylight, and we much regret they were not impressed in some less 

 conspicuous place. 



I am, etc." 



Wothlifs Improvement in Photography Jacob Wothly, a Ger 

 man photographer, has made an improvement in photographic printing 

 which promises to be of much importance. Instead of preparing 

 the paper, upon which the print is to be made, with albumen, he 

 employs collodion ; and, instead of the nitrate of silver as a sensitizer 

 he uses one of the double salts of uranium. This salt is mixed with 

 the collodion, and the only operation required is to pour the collodion 

 upon the sheet of paper and hang it up to dry. 



Concerning this discovery, the London Times f of October, 1864, 

 remarks : 



" The new process which has been discovered in Germany by Herr 

 Wothly, and from him has been named ' Wothlytype,' discards nitrate 

 of silver, and discards albumen. For the former it uses a double salt 

 of uranium, the name of which is at present kept secret ; for the 

 latter it uses collodion. We have explained that by the ordinary 

 method, the paper to be printed is sized with albumen, and the sur- 

 face of the albumen receives the silver preparation, which is sensitive 

 to the light, and shows the printed image. The paper thus does not 

 receive the image, but is, as it were, a mere bed on which lies the 

 material that does receive it. By the substitution of collodion for 

 albumen, a different result is reached. In the first place, the film of 

 collodion on the paper yields a beautiful smooth surface on which to 

 receive the image, and the result is, that pictures are printed upon it 

 with wonderful delicacy. In the second place, the collodion, before 

 it is washed upon the. paper, is rendered sensitive by being combined 

 with the salt of uranium. The sensitiveness, therefore, is not on the 

 Mirf.ice alone of the collodion film, it is in the film itself, and so com- 

 pletely passes through it, that even if it be peeled away from the 

 paper, the image which it receives will be found on the paper beneath. 

 The vehicle thus employed is not less superior to all others yet known 



