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.
Popularly, sodium carbonate or bicarbonate.
Caustic soda, sodium hydroxide. -- Cooking soda, sodium bicarbonate. [Colloq.] -- 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. [Colloq.]
© Webster 1913.