Surface Tension of Urine during the Menstrual Cycle

Abstract

WE have recently carried out in this laboratory surface tension measurements in connexion with the excretion of capillary-active substances in the urine of the normal human female. Over a period of twenty-eight days the surface tension of the first morning specimen each day was determined, and the centrifuged deposit examined microscopically for blood corpuscles, so that the onset of menstruation could be ascertained as early as possible. A typical curve of the variation is shown in Fig. 1, and from this the following interesting observations can be made.