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 |