86 PHOTOGRAPHIC PROCESSES. 



To KEEP THE EMULSION. 



Take the emulsion strips and put them into a wide- 

 mouth fruit jar ; pour enough alcohol on to cover the 

 emulsion, screw on the top, and the emulsion will 

 keep. When you wish it, take up what you want to 

 use, wash it to free it of alcohol, drain and melt. 

 Add albumen, alcohol, and chrome alum as before, 

 and flow the plates. 



If you are in a hurry and do not wish to wait the 

 three to five days to gain rapidity, you can take 

 emulsion as soon as all free silver has been formed 

 into bromide of silver. Melt the emulsion, heat to 

 140 to 150, add 480 grains of bromide of potassium, 

 and let stand in the water at 140 to 150 for 30 

 minutes. Set aside in temperature of 40 to 60 to 

 set, and then wash and flow the plates. But if this 

 way is chosen, the emulsion must be washed in a 

 different way than described above, as the soluble 

 ammonium nitrate left in the emulsion will not wash 

 out as in the other process of washing. When the 

 bromide of silver is formed in the gelatine, by placing 

 the silvered gelatine in the brine the emulsion does 

 not take up the soluble nitrate of ammonium, so only 

 needs sufficient washing to free the outside from the 

 nitrate of ammonium. But in the latter case the 

 nitrate of ammonium is all through the emulsion and 

 must be treated as follows : Squeeze the set emulsion 

 through a piece of coarse canvas into a large bowl of 

 water, take another large bowl, tie a piece of coarse 



