a substance formed by the action of sodium glycol on ethylene-diamine hydrochloride, consisting of small alkaline deliquescent crystals with a saline taste and soluble in water. It was originally introduced into medicine as a solvent for uric acid. When taken into the body the drug is partly oxidized and partly eliminated unchanged. Outside the body piperazin has a remarkable power of dissolving uric acid and producing a soluble urate, but in clinical experience it has not proved equally successful. Lycetol, lysidine and sidonal are bodies having similar action.