114 PHOTOGRAPHIC FACTS AND FORMULAS 
A. Sodium bisulphite 39 g 24 oz. 
Sodium sulphite, dry 39 g 24 02. 
Hot water 1000 ccm 64 oz. 
Boil for 5 minutes and add when cool: 
Pyrogallol 3l¢g 2 02, 
B. Sodium carbonate, dry 62.5 g 4 oz. 
Water | 1000 ccm 64 oz. 
Potassium metabisulphite must not be substituted for the 
bisulphite in the above formulas. . 
Pyro-soda developer for Cramer plates.— 
A. Sodium bisulphite 5g 75 gr. 
Pyrogallol 30 ¢ 1 oz. 
Water 480 ccm 16 oz. 
B. Sodium sulphite, dry 60 g 2 02. 
Water 480 ccm 16 oz. 
C. Sodium carbonate, dry 30 g 1 oz. 
Water 480 ccm 16 oz. 
For tray use: 
Solution A 100 ccm 1 oz. 
Solution B ; 100 ccm ez. 
Solution C 100 ccm 1 'o7. 
Water 800 ccm 8 02. 
For tank use: 
Solution A 250 ccm 214 02. 
Solution B 350 ccm 314 oz. 
Solution C 250 ccm 2Y4 oz. 
Water 5800 ccm 58 oz. 
Temperature 65° F. Time 20 minutes. 
Cramer’s Pyro-Acetone.—Stock pyro solution: 
Sodium bisulphite B,20'2 25 gr. 
Pyrogallol 62.5 ¢g 1 oz. 
Sodium sulphite, dry 182 g 234 02. 
Water 1000 ccm 16 oz. 
