ELEMENTARY PHOTO-MICROGRAPHY. 107 



of B solution, and gradually adding more if de- 

 velopment 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 fogging need be feared. The plate may be lifted 

 out occasionally and held up to the lamp to view 

 the image, looking at the back of the plate also to 

 see if the image appears at that side. If the object 

 shows clearly and is well denned when held against 

 the light, and also shows on the back of the plate, 

 development may be considered sufficient. 



A good printing density will be secured if develop- 

 ment be continued until it has acted through the 

 full thickness of film and the background appears 

 quite black on the other side of plate, though it is 

 possible to clog fine details by over-development, 

 and spoil the printing quality of the negative. 



It would assist a beginner to form a correct 

 judgment about density if he borrowed a correctly 

 exposed and developed plate from some friend. 

 This would serve as a standard with which com- 

 parison of his own results could be made at leisure. 



