Urinary infection is the most frequent of genito-urinary disturbances. Sometimes it is the primary and principal disease, but more often it occurs as an added and secondary burden, and whatever the abnormality it is always an imminent possibility. The significance of the condition is given unusual emphasis by a recent analysis of the postmortem records of the Johns Hopkins Hospital (1912-1914). These records show that the cause of death, in more than half of the fatalities in the urologic service, was an infection which, as indicated clinically in the histories and pathologically by finding cystitis, pyelonephritis or pyelitis, probably spread in every instance from the urinary tract. These and other facts emphasize the great danger of urinary infection, and the necessity for the development of a more efficient therapeusis. The object of this paper is to present a study of the limitations of the known urinary antiseptics, to correlate these