184 PHOTOGRAPHIC FACTS AND FORMULAS 
Paramidophenol may also be used (Hanneke) : 
Paramidophenol hydrochloride 7g 54 gr. 
Citric acid 8g 61 gr. 
Sodium sulphite, dry 25¢ 192 gr. 
Water 1000 ccm 16 oz. 
Liesegang’s aristogen for the same purpose was said to be: 
Hydrochinon 10g 77 gr. 
Sodium acetate 10g 77 gr. 
Citric acid 10g 77 gr. 
Sodium sulphite, sat. sol. 500 ccm 8 oz. 
Water | 500 ccm 8 oz. 
It was discovered by Wilson that an alkaline developer could 
be used, if the print were first immersed in potassium bro- 
mide solution, so as to convert the whole of the silver salts 
into bromide. After exposure the print should be immersed, 
without washing, in a 10 per cent solution of potassium 
bromide for 5 to 10 minutes, then well washed, and treated 
with the following: 
A. Hydrochinon 18.2 g 140 ger. 
Sodium sulphite, dry 45¢ 35 gr. 
Sulphurous acid 9 ecm 70 min. 
Potassium bromide 45¢ 35 gr: 
Water 1000 ccm 16 oz. 
B. Caustic soda 9g 70 gr. 
Sodium sulphite, dry 9g 70 gr. 
Water 1000 ccm 16 oz. 
C. Ammonium carbonate 36.5 g 280 gr. 
Ammonium bromide 36.5 g 280 gr. 
Water 1000 ccm 16 oz. 
Mix in equal parts before use. The following is simpler: 
A. Hydrochinon 22.8¢ 175 gr. 
Sodium sulphite, dry 114¢ 87.5 gr. 
Sulphurous acid 114¢ 87.5 gr. 
