232 PHOTOGRAPHIC FACTS AND FORMULAS 
When dissolved, pour into: 
Nitric acid 500 ccm 10 oz. 
Water | 500 ccm 10 oz. 
To make the bath use: 
Molybdate solution above 250 ccm 4 oz. 
Water 1000 ccm 16 oz. 
Potassium metabisulphite 50 g 384 gr. 
This should be used in artificial light, and the prints well 
washed. 
ToNnING BY REDEVELOPMENT (Mamnly).—Various tones can 
be obtained by bleaching prints with the following baths and 
redeveloping with the given developers: 
A. Potassium ferricyanide 33 g 250 gr. 
Ammonium bromide 40 g 31Mier 
Water 1000 ccm 16 oz. 
B. Cupric sulphate 50 g 384 gr. 
Sulphuric acid 6.5 ccm 50 min. 
Common salt 50 g 384 er. 
Water 1000 ccm 16 oz. 
C. Potassium bichromate 20 ¢° Ep 
Sulphuric acid 50 ccm 384 min. 
Salt 100 g 768 gr. 
Water 1000 ccm 16 oz. 
After bleaching in one of the baths, the prints should be 
washed for 20 to 30 minutes, and redeveloped in the fol- 
lowing : 
I. Metol 10g VA Asa 
Sodium sulphite, dry 33 g 250 gr. 
Sodium carbonate, dry 33 g 250 ger. 
Water 1000 ccm 16 oz. 
II. Hydrochinon | 30g 250 gr. 
Potassium metabisulphite 16g 123 ee 
Water 1000 ccm 16 oz. 
