The DARKROOM COOKBOOK, Third Edition

SODA (see Sodium carbonate)
Pharmacopoeia 191
SODIUM ACETATE
Synonyms: Acetate of soda.
Appearance: Colorless, transparent, effl orescent crystals.
Uses: Toning baths; retarder in hydroquinone developer; used to buffer acidity of acid solutions.
Notes: Keep in a tightly sealed bottle in a cool place.
SODIUM ASCORBATE
Synonyms: Soda ascorbate, Sodium Isoascorbate, Vitamin C sodium.
Appearance: White crystals.
Uses: Ecologically friendly developing agent.
Notes: Sodium ascorbate is usually in combination with metol or Phenidone. It may be used
as a substitute for ascorbic acid in fi lm developers. It may also be used as a substitute for hydroquinone.
Try using 1.8 times the weight of the hydroquinone. The alkali does not have to
be increased because sodium ascorbate is not acidic.
Substitutions: Sodium ascorbate is available in health food stores and the canning goods
department of some grocery stores. Ten grams of sodium ascorbate can be substituted with
8.89 grams of ascorbic acid. Sodium ascorbate can be replaced with sodium isoascorbate,
weight for weight.
(see Acid, ascorbic; Hydroquinone; and Sodium isoascorbate)
SODIUM BICARBONATE
Synonyms: Acid sodium carbonate, Baking soda, Bicarbonate of soda, Monosodic carbonate,
Sodium hydrocarbonate, Sodium hydrogen carbonate.
Appearance: Fine, white powder.
Uses: In hypo baths for fi xing self-toning papers; in gold toning baths; in developers to
nhibit fog.
SODIUM BISULFATE
Synonyms: Sodium acid sulfate, Sodium hydrogen sulfate.
Appearance: White, crystalline powder.
Uses: Acid rinse and stop baths. In combination with sodium acetate, used as a substitute for
acetic acid.
Notes: Sodium bisulfate can be used in conjunction with sodium chloride to make a substitute
for hydrochloric acid.
SODIUM BISULFITE
Synonyms: Acid sulfi te of soda, Leucogen.
Appearance: White, crystalline powder.
Uses: In acidulating and preserving fi xing baths; as a preservative for pyro developer; for
removing silver stains from printing-out paper.
Notes: Can be substituted weight for weight with sodium metabisulfi te.