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. [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.]
Hear it pronounced