NEGATIVE MAKING 



6l 



last, feeling sure of this important work being 

 accomplished, let us take it from the bath, 

 rinse in water and examine. "A fine nega- 

 tive," you exclaim, and " made by an objective 

 of very perfect construction," is added by all. 

 It is the negative from which the frontispiece 

 to this book was reproduced, and I think does 

 credit to all concerned in its making the op- 

 tician, the plate-maker and (modestly) to the 

 photographer. It must now be thoroughly 

 washed to eliminate every trace of hypo from 

 the film. An hour or two in running water, 

 when the usually dirty Philadelphia fluid which 

 passes by that name is at all fit for use, will 

 suffice for this purpose; otherwise numerous 

 changes of filtered water during many hours 

 are necessary to remove the last traces of this 

 necessary but treacherous salt. Then swab- 

 bing off under the tap with a tuft of cotton- 

 wool, a final rinse in filtered water and placing 

 in a rack for spontaneous drying will complete 

 our negative. The latter process may be 

 accelerated by standing the rack in a current 

 of warm, dry air, free from dust. I would not 

 advise my readers to adopt the following 

 directions, gravely given in a recent English 

 work on photo-micrography by an eminent 

 authority. 



