60 ELEMENTARY PHOTO-MICROGRAPHY. 



during exposure, and if frequent exposures are made 

 at one time, neutral tint spectacles during the time 

 the light is full on will be found a relief. Having 

 made the exposure and lowered the light, the paper 

 is taken from the frame and dipped into clean water, 

 so that it will lie flat in the developing dish. The de- 

 veloper is swept over the paper, keeping it freely on 

 the move until the required depth of tone be 

 reached, when the paper is rinsed in clean water 

 and immersed edgewise, face up, in the fixing bath 

 made up as follows : 



Hypo ... ... ... 4 ounces 



Water 16 



To this are added 



Sodium sulphite ... ... i dram 



Acetic acid ... ... ... 6 drams 



Alum i dram 



dissolved in one and a quarter ounces of water. 



The prints are kept moving a few moments, and 

 afterwards allowed to remain fifteen minutes. An 

 hour's washing in running water or in eight changes 

 of water, as before described, completes the process. 

 A thorough washing should be given. The above 

 bath keeps clean much longer than a simple hypo 

 and water bath, and can be used time after time. 



Platinotype printing is at once the simplest, most 

 permanent, and most effective of all processes. 

 Good negatives yield prints equal in beauty to a 

 fine steel engraving, with rich gradations of tone 

 very pleasing to behold. The whole process can be 



