CAMERA AND PHOTOGRAPHIC APPLIANCES 35 



Although the sensitized plates are neces- 

 sarily developed in the dark-room, they are 

 not properly appliances of that indispensable 

 apartment. In fact they have no business 

 there, save at the times of being placed in 

 the holders and development. They should 

 be stored in a dry, well-ventilated room, where 

 no deleterious gases or fumes can possibly 

 gain access to them. The too common prac- 

 tice of keeping plates in dark-rooms is a very 

 frequent cause of fog and other deteriorations 

 in them, and the avoidance of so doing cannot 

 be too earnestly urged. 



As to the plates themselves. It may be 

 broadly stated that any of the numerous 

 brands now in the market are capable of 

 furnishing satisfactory photo - micrographic 

 negatives if properly manipulated, though not 

 equally so with all classes of subjects. Some 

 of these require certain qualities not found 

 in all plates for their best rendition. As a 

 rule, very sensitive emulsions yield soft nega- 

 tives; slower ones giving greater density, with 

 inclination toward harshness. For the greater 

 part of all microscopical objects, orthochro- 

 matic or isochromatic u color-correct " plates 

 are infinitely superior to all others. Indeed 

 so greatly are they better that for a long time 



