Sodium bicarbonate \Sodium bicarbonate\,
   a white crystalline substance, {HNaCO3}, with a slight
   alkaline taste resembling that of sodium carbonate. It is
   found in many mineral springs and also produced
   artificially,. It is used in cookery, in baking powders, and
   as a source of carbonic acid gas (carbon dioxide) for soda
   water. Called also {baking soda}, {cooking soda},
   {bicarbonate of soda}, {bicarb}, {saleratus}, and
   technically, {acid sodium carbonate}, {sodium acid  carbonate}, {primary sodium carbonate}, {sodium dicarbonate},
   etc.
   
[1913 Webster]