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Chlorhydroquinone alone is not often used as a negative developer, but the following formula gives good results.

Sodium sulphite anhydrous100grams
Potassium carbonate150grams
Water to make1liter
Mix chemicals in order.

For strong contrast, dilute with 3 parts of water. For softer negatives dilute 1:5. Add 5 mililiters of 10% potassium bromide solution to 0.5 liters of working solution.

The image appears in 20 seconds and development is complete in 4–5 minutes at 18.5°C.