PHP IRON PROCESSES 278 
Water 1000 ccm LOZ: 
Potassium bichromate 
solution, 1:48 6tol2ccm ‘'3to6drops 
Allow to stand 24 hours in the dark; then filter. 
B. Silver nitrate 100 g 50 ger. 
Citric acid 60 g 30 gr. 
Tartaric acid 20 g 10 er. 
Water 1000 ccm 1 oz. 
First coat the paper with A, and allow to dry; then coat with 
B. Print in the sun until the half tones are slightly tinted. 
For sepia tones wash and fix in: 
Salt 4g ior 
Hypo 4g 12 gr. 
Water 1000 cem 6 oz. 
For green tones immerse the print in: 
Potassium ferricyanide 3g 4 gr. 
Nitric acid 3 ccm 4 drops 
Water 1000 cem 4 oz. 
Remove from this solution just before the green tone is 
reached, and fix in weak hypo. 
