Part 339

Mix Nos. I and II, equal parts, for use.

«Eikonogen Hydrochinon Developer.»—

I.—Distilled or pure well water 32 ounces Sodium sulphite, crystals 4 ounces Eikonogen 240 grains Hydrochinon 60 grains

II.—Water 32 ounces Carbonate of potash 4 ounces

To develop, take

No. I. 2 ounces No. II. 1 ounce †Water 1 ounce

──────────────────────────── † For double-coated plates use 5 ounces of water.

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By hydrometer:

I.—Sodium sulphite, solution to test 30 34 ounces Eikonogen 240 grains Hydrochinon 60 grains

II.—Carbonate of potash solution to test 50

To develop, take

No. I. 2 ounces No. II. 1 ounce ‡Water 1 ounce

──────────────────────────── ‡ For double-coated plates use 5 ounces of water.

«Hydrochinon Developer.»—

I.—Hydrochinon 1 ounce Sulphite of soda, crystals 5 ounces Bromide of potassium 10 grains Water (ice or distilled) 55 ounces

II.—Caustic potash 180 grains Water 10 ounces

To develop:

Take of I, 4 ounces; II, 1⁠/⁠2 ounce. After use pour into a separate bottle. This can be used repeatedly, and with uniformity of results, by the addition of 1 drachm of I and 10 drops of II to every 8 ounces of old developer.

In using this developer it is important to notice the temperature of the room, as a slight variation in this respect causes a very marked difference in the time it takes to develop, much more so than with pyro. The temperature of room should be from 70° to 75° F.

«Metol Developer.»—

I.—Water 8 ounces Metol 100 grains Sulphite of soda, crystals 1 ounce

II.—Water 10 ounces Potassium carbonate 1 ounce

Take equal parts of I and II and 6 parts of water. If more contrast is needed, take equal parts of I and II and 3 parts of water, with 5 drops to the ounce of a 1⁠/⁠10 solution of bromide of potassium.

«Metol and Hydrochinon Developer.—»

I.—Pure hot water 80 ounces Metol 1 ounce Hydrochinon 1⁠/⁠8 ounce Sulphite soda, crystals 6 ounces

II.—Pure water 80 ounces Carbonate soda, crystals 5 ounces

To develop, take of