204 PRACTICAL PHOTO-MICROGRAPHY 



to dry. In placing the plates in such racks it should be noted 

 that they do not dry properly if put too close together ; hence 

 a rack holding one \iofeent plates should not have more than 

 three or four plates placet! in^to dry at once, and these should 

 be so placed that the great eat* air-space possible is allowed 

 between the sensitive films. If dry-plates are stored in the 

 dark-room, care should be taken to ensure that they are 

 kept thoroughly dry, and so far as is possible, in a position 

 in which they are not subjected to any rapid changes of 

 temperature. 



