So″da (?), n. [It., soda, in OIt., ashes used in making glass, fr. L. solida, fem. of solidus solid; solida having probably been a name of glasswort. See Solid.] (Chem.) (a) Sodium oxide or hydroxide. (b) Popularly, sodium carbonate or bicarbonate.
Caustic soda, sodium hydroxide. — Cooking soda, sodium bicarbonate. — Sal soda. See Sodium carbonate, under Sodium. — Soda alum(Min.), a mineral consisting of the hydrous sulphate of alumina and soda. — Soda ash, crude sodium carbonate; — so called because formerly obtained from the ashes of sea plants and certain other plants, as saltwort (Salsola). See under Sodium. — Soda fountain, an apparatus for drawing soda water, fitted with delivery tube, faucets, etc. — Soda lye, a lye consisting essentially of a solution of sodium hydroxide, used in soap making. — Soda niter. See Nitratine. — Soda salts, salts having sodium for the base; specifically, sodium sulphate or Glauber's salts. — Soda waste, the waste material, consisting chiefly of calcium hydroxide and sulphide, which accumulates as a useless residue or side product in the ordinary Leblanc process of soda manufacture; — called also alkali waste. — Soda water, originally, a beverage consisting of a weak solution of sodium bicarbonate, with some acid to cause effervescence; now, in common usage, a beverage consisting of water highly charged with carbon dioxide (carbonic acid). Fruit sirups, cream, etc., are usually added to give flavor. See Carbonic acid, under Carbonic. — Washing soda, sodium carbonate.