Salt of sorrel Meaning, Definition & Usage

Definitions
  1. (Old Chem.), acid potassium oxalate, or potassium quadroxalate, used as a solvent for ink stains; so called because found in the sorrel, or Oxalis. Also sometimes inaccurately called salt of lemon.
Definitions
  1. (Chem.), binoxalate of potassa; so called because obtained from the juice of Rumex Acetosella, or Rumex Axetosa.

Webster 1913