Part 342

Sulphite of soda crystallized 468 grains Water 2 5⁠/⁠8 ounces Caustic potash (purified in sticks) 108 grains Pyrocatechin 108 grains

Mix for a formally fixing plate of 5 x 7 inches.

Developer 3 drachms Fixing soda solution (1:5) 5 1⁠/⁠2 drachms Water 1 ounce

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.»—Pyrocatechin, 2 per cent solution (2 grams pyrocatechin in 100 cubic centimeters of water).

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 potassium 120 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 Pyro 10 grams

«Hauff’s Adurol Developer.»—One solution.

Water 10 ounces Sulphide of sodium, crystals 4 ounces Carbonate of potassium 3 ounces Adurol 1⁠/⁠2 ounce

For studio work and snap shots take 1 part with 3 parts water.

For time exposures out-door take 1 part with 5 parts water.

«Glycin Developer.»—

I.—Hot water 10 ounces Sulphite of sodium, crystals 1 1⁠/⁠4 ounces Carbonate of sodium 1⁠/⁠4 ounce Glycin 1⁠/⁠2 ounce

Add to water in order given

II.—Water 10 ounces Carbonate of potash 1 1⁠/⁠4 ounces

For normal exposure take I, 1 ounce; II, 2 ounces; water, 1 ounce.

«Imogen Developer.»—

I.—Hot water 9 ounces Sulphite of sodium, crystals 385 grains Imogen 123 grains

II.—Hot water 4 1⁠/⁠2 ounces Carbonate of sodium 2 ounces

For use take 2 ounces of I and 1 ounce of II.

«Diogen Developer.»—

Water 9 ounces Sulphite of sodium 3 1⁠/⁠2 ounces Diogen 7 drachms Carbonate of potassium 4 1⁠/⁠2 ounces