108 ELEMENTARY PHOTO-MICROGRAPHY. 



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 

 cloth or blotting paper, and it is put into the rack 

 to dry. The rack should be in a warm room free 

 from dust, but not too near a fire lest the gelatine 

 melt and spoil the plate. Slow drying will often 

 spoil the negative by leaving various degrees of 

 density in the film. 



Flooding the plate with methylated spirit will 

 assist quick drying. If tap water be used for 

 washing, it should be seen that it is not charged 

 with air, which causes the gelatine to separate 



