The urgent need of an efficient internal urinary antiseptic is fairly measured, not only by the extensive researches which this need has stimulated, but somewhat more strikingly by the universal use of the more or less complicated procedures involving instrumentation of the bladder and ureters for the purpose of applying bactericidal substances to the mucosa of the urinary tract. Even when applicable, these methods, requiring special skill and always attended with considerable discomfort to the patient, would obviously be minimized were any substance known which, administered internally, would impart to the urine either bactericidal or bacteriostatic properties of sufficient strength and continuity to effect equally good or better clinical results. Hexamethylenamin and the many closely allied compounds which have been exploited to the medical profession under various names were thought for a time to be promising, not only as urinary antiseptics but as general internal antiseptics as well. This hope