Cathartics are divided into laxatives and purgatives. Manna, tamarinds, castor oil, sulphur, and magnesia are _laxatives;_ senna, rhubarb, jalap, colocynth, buckthorn, aloes, cream of tartar, scammony, calomel, Epsom salts, Glauber's salts, sulphate of potash, and Venice turpentine are _purgatives._