ELEMENTARY PHOTO-MICROGRAPHY. 79 



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. 



If, however, the whole image appears thin and 

 ghost-like, there is a fault in the exposure. Should 

 the high lights represented by black places on the 

 negative come up slowly and the other details do 

 not follow, the plate is under-exposed. With 

 patience, perhaps a printable negative may be got, 

 but as a rule it is better to throw it away and 

 make another. If, on the other hand, the image 

 rushes up quickly, the plate is over-exposed and 

 the developer must be diluted, adding also more 

 bromide to prevent fogging. 



After development is completed, the plate may 

 be washed in water and put in the fixing bath to 

 stay fifteen minutes. 



From this it is transferred to the washing 

 trough, and the water changed eight times, allow- 

 ing it to soak for five minutes between each change. 

 The back of the negative is then dried with a 



