200 PHOTOGRAPHIC FACTS AND FORMULAS 
both gelatine and paper and its tendency to give rusty black 
tones. Amidol and metol-hydrochinon, also called M. Q., 
are the favourites; the former tends to give blue-black, and 
the latter pure black tones. 
Amidol—tThis developer will not keep more than three 
days, and the most convenient method is to make up a 5 per 
cent solution of dry sodium sulphite, add 0.1 per cent of 
potassium bromide (¥4 gr. to the ounce), add 0.8 per cent 
amidol (4 gr. to the ounce), and dilute with an equal bulk of 
water just before use: 
Sodium sulphite, dry 34¢ 260 gr. 
Potassium bromide 13g 10 gr. 
Water 1000 ccm 16 oz. 
When dissolved, add: 
Amidol 522 40 er. 
Metol-Hydrochinon.—The mean of the maker’s formulas 
is: 
Metol je 27 gr. 
Hydrochinon 3g 23 gr. 
Sodium sulphite, dry 21g 160 gr. 
Sodium carbonate, dry l6g 123 gr. 
Potassium bromide 13g 10 gr. 
Water 1000 ccm 16 oz. 
Eastman Metol-hydrochinon Developer. 
Elon (metol) 5g YZ oz. 
Sodium sulphite, dry 75g 7% 02. 
Hydrochinon 20 g 2 02: 
Sodium carbonate, dry 105 ¢ 1034 oz. 
Potassium bromide 2.5 2 120 gr. 
Wood alcohol 130 ccm 13 oz. 
Hot water 1000 ccm 100 oz. 
For use mix 1 part with 6 parts water. Temperature 21° C. 
(708 Es)! 
