PEACTICAL PHOTO-MICROGRAPHY. Ill 



Our latest color sensitizing bath is due to Mr. Bothamley, 

 and gives considerable sensitiveness to yellow, but not to red. 

 The general sensitiveness of the plate is raised about three 

 times, and the aptitude for giving density greatly increased. 

 No washing is required, and the plates keep well. A rather 

 slow plate should be chosen, and the caution about proportion 

 of iodide must be kept in mind. The proper erythrosin is 

 that of the Badische-anilin-and-soda-fabriJc, called " Erythro- 

 sin B." The use of ammonia in this way is covered by patent 

 in England. The ammonia may be omitted, but five or six 

 times more exposure will be required. (Bothamley.) 



Erythrosin solution (1 to 1000) 1 part. 



Ammonia (1 to 10) 1 part. 



Distilled water 8 parts. 



Bathe the plate for two minutes. Dry. No washing needed. 



