ELEMENTARY PHOTO-MICROGRAPHY. 5 1 



is opened and a plate put in the dish, gelatine side 

 up, taking care not to touch the gelatine side with 

 the fingers. Plates must always be lifted by the 

 edges. If the dark slide has been kept clean, there 

 is no advantage in first brushing the slide with a 

 camel-hair flat brush or with velvet, as the danger 

 of leaving dust specks on the plate is as great as 

 getting them from the dark slide. The plate 

 should not be washed before development. 



The developer must be swept over it quickly in 

 such a way that no part of the plate is left dry, even 

 for a moment, and the dish gently rocked to> keep 

 the solution constantly on the move all over the 

 surface of the plate. If the developer be insuffi- 

 cient in quantity, dry places will be noticed on the 

 plate over which the developer will not readily flow. 

 This should not be allowed. The developer should 

 be used at a temperature of about 60. In very 

 cold weather this is important, or the action, if 

 there is any at all, will be slow. Boiled water that 

 has gone nearly cold may be used, commencing 

 with less than the full quantity of B solution, and 

 gradually adding more if development be too slow. 



A dilute developer is safest for a beginner. 

 In half a minute or more, traces of the image will 

 begin to appear if the exposure has been correct, 

 and development must be continued until sufficient 

 density be obtained. There should be no hurry. 

 Under-development is a fault of most beginners. 

 If the narrow strips at the edges of the plate which 

 have not been exposed keep white no danger of 



