Miscellaneous Formulae: 



Farmer's Reducer R-4A: (Cutting - for clearing shadow areas) 



Stock Solution; 



Dissolve 37.5 g. potassium ferricyanide in enough water to make 500 cc, 

 For use, take 30 cc. of stock, 96 cc. of 30% Hypo, and enough water to make 

 1 liter. Mix the stock and hypo, then add the water and pour the mixed sol- 

 ution at once over the negative to be reduced. When sufficient reduction 

 has occurred, remove the negative and wash thoroughly. The mixed reducer 

 will keep only briefly. 



General Tray Cleaner TC-1: 



Dissolve 82 g. of potassium dichromate in 910 cc of hot water. Cool, 

 and then add slowly with constant cooling and stirring, 87 cc. of cone, 

 sulfuric acid. 



Keeping Properties of Solutions: 



The figures given are for no loss in quality on standing without use. 

 Developers except D-72: 



1. In tray - 24 hours. 



2. In gallon tank - 1 month. 



3. In stoppered bottle, full 



6 months. 



half-full - 2 months. 



D-72; 



1. Tray - 24 hours. 



2. Gallon tank - 2 weeks. 



3. Stoppered bottle, full - 3 months. 



half-full - 1 month 



Stop-Baths: (SB-1, 3, 5) 



1. Tray - 3 days. 



2. Tank - 1 month 



3. Stoppered bottle - indefinitely 



Acid-Fixing Bath F- 5 : 



1. Tray - 1 week 



2. Gallon tank - 1 month 



3. Stoppered bottle, full - 3 months. 



half-full - 2 weeks 



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