The process of developing and fixing with this solution is accomplished in a {527} few minutes. The picture first appears usually, strengthens very quickly, and shortly after the fixing is entirely done.

Ellon’s Pyrocatechin Developer.

Carbonate of potassium, 10 per cent solution (10 grams carbonate in 100 cubic centimeters of water).

For use take equal parts and add water as desired.

Imperial Standard Pyro Developer.—
I.—Metabisulphite of potassium120 grains
Pyrogallic acid 55 grains
Bromide of potassium 20 grains
Metol 45 grains
Water 20 ounces
II.—Carbonate of soda  4 ounces
Water 20 ounces

For use mix equal parts I and II.

Bardwell’s Pyro-acetone Developer.—
Water 4 ounces
Sulphite of sodium (saturated solution) 4 drachms
Acetone 2 drachms
Pyro10 grams
Hauff’s Adurol Developer.