Hydrate of soda
Sodium hydroxide solid
Red Devil Lye
White, deliquescent pellets or flakes
High-energy accelerator or alkali sometimes used to activate low-energy developing agents (e.g. hydroquinone).
Caustic alkalies are most often used where a powerful and quick-acting developer is required. Developers compounded with caustic alkali have poor keeping properties and are soon exhausted.
Store in a well-sealed bottle. Weigh it rapidly as it can pick up moisture from the air and change its weight.
Cautions: Of all the chemicals commonly used in the black & white darkroom, this is perhaps the most caustic. It is the same chemical used in many commercial drain cleaners.