Fuller’s soap

(Heb. borith mekabbeshim, i.e., “alkali of those treading cloth”). Mention is made (Prov. 25:20; Jer. 2:22) of nitre and also (Mal. 3:2) of soap (Heb. borith) used by the fuller in his operations. Nitre is found in Syria, and vegetable alkali was obtained from the ashes of certain plants.