96 PHOTOGRAPHIC PROCESSES. 



As it would be difficult to weigh a less quantity of 

 pyrogallic acid, and as the resulting solution is far 

 too large a quantity for a single quarter plate, we 

 recommend the development of at least four at the 

 same time. 



Should the picture flash out suddenly after the 

 application of the developer, over exposure is indica- 

 ted; the developer should be immediately poured 

 back into the measure, the plates washed for a 

 second or two under the tap, and left covered with 

 water in the dish while one or two drops of a solu- 

 tion, 



Bromide of Ammonia, 1 oz. 

 Water, 1 oz. 



are added to the developer. 



The water is poured from the plates, the developer 

 again applied, the process carefully watched, and the 

 solution poured off before any symptoms of fogging 

 appear in the whites of the negative. 



In the opposite case, where the image is slow in 

 making its appearance, the solution should be poured 

 back into the measure, and a quantity of no. I. solu- 

 tion, varying from J to double the quantity at first 

 used, added to the developer, and at once applied to 

 the plate, without previous washing. 



It will be seen that owing to the variations ad- 

 missible in the strength and preparations of the 

 solutions employed, the condition and density of 

 the negative is almost completely under control, if 

 the exposure has been kept within anything like 

 reasonable limits. 



