90 ELEMENTARY PHOTO-MICROGRAPHY. 



This is a stock solution, and may be bottled for 

 future use. The paper is floated on the bath, face 

 downwards, turned quickly over, and development 

 watched. A black and white image will rapidly 

 appear, and when sufficient depth of tone is 

 obtained, the print may be removed to a bath 

 composed of 



Water . . . . . . 10 ounces. 



Hydrochloric acid . . ij drams. 



Any of the lemon colour left will here be cleared 

 away, and black and white tones only remain. 

 After five minutes in this bath the prints are 

 transferred to a similar but rather more dilute 

 bath for ten minutes, then to three baths of clean 

 water for ten minutes each, into the second of 

 which a few grains of sodium carbonate have been 

 added to neutralise any acid left in the prints. 



Wollf's " indelible railway pencil " is excellent 

 for any retouching with either bromide or platino- 

 type prints. Photo-micrographs kept in a special 

 album having only one print on a page show to 

 better advantage than when mixed with others of 

 a miscellaneous kind. 



