The auscultatory method for the determination of arterial blood-pressure in man, described by Korotkoff in 1905,1 has called forth numerous papers particularly from those making a clinical application of the method. There appears to be unanimity of opinion that the systolic pressure is established with the onset of the brachial sound during the fall of proximal constricting pressure, but the point of diastolic pressure, originally established by Korotkoff as coincident with the disappearance of all sound, has been variously interpreted. In a recent paper by Taussig and Cook,2 the literature is fully presented. These authors establish the diastolic pressure at the fourth phase in the production of the sound ; that is, at the point at which, during the fall of constricting pressure, the sound changes from sharp to dull, a change which is generally recognized to occur in normal subjects just before the cessation of sound.