Tolidol Developer.
| Water | 16 ounces |
| Tolidol | 24 grains |
| Sodium sulphite | 72 (144) grains |
| Sodium carbonate | 96 (240) grains |
The figures in parenthesis are for crystals. It will be seen that in every case {526} the weight of sulphite required in crystals is double that of dry sulphite, while the weight of carbonate crystals is 2 1/2 times as much as dry carbonate.
For tank development Dr. John M. Nicol recommends the standard formula diluted with 6 times the amount of water, and the addition of 1 drop of retarder to every ounce after dilution.
To obtain very strong negatives:
| Water | 16 ounces |
| Tolidol | 50 to 65 grains |
| Sodium sulphite | 80 (160) grains |
| Sodium carbonate | 120 (300) grains |
On some brands of plates the addition of a little retarder will be necessary.
If stock solutions are preferred, they may be made as follows:
| Solution A | |
|---|---|
| Water | 32 ounces |
| Tolidol | 1 ounce |
| Sodium sulphite | 1 (2) ounce |
| Solution B | |
| Water | 32 ounces |
| Sodium sulphite | 2 (4) ounces |
| Solution C | |
| Water | 32 ounces |
| Sodium carbonate | 4 (10) ounces |
If preferred, stock solutions B and C can be made by hydrometer, instead of by weight as above. The solutions will then show: