One part rodinal to 30 parts pure water.

Use repeatedly, adding fresh as required.

Bromo-Hydrochinon Developer

For producing great contrast and intensity, also for developing over-exposed plates.

I

Distilled or ice water 25 ounces Sulphite of soda, crystals ............ 3 ounces

Hydrochinon....... 0.5 ounce

Bromide of potassium ............ 0.25 ounce

Dissolve by warming, and let cool before use.

II

Water............. 25 ounces

Carbonate of soda, crystals.......... 6 ounces

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. 1............. 2 ounces

No. II............. 1 ounce

*Water............. 1 ounce

* For double-coated plates use 5 ounces of water.

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

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, 0.5 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.