Although estimation of the rate of sedimentation of erythrocytes has proved to be a valuable laboratory aid in clinical medicine, it is not used as widely or as wisely as it should be used. There are two chief reasons for this. In the first place, it is erroneously regarded by many physicians as a difficult technical procedure. A survey of the voluminous literature on the subject will disclose that much of it is devoted to technicalities involved in performing and interpreting the test. The original methods used by Fahraeus,1 Westergren2 and Linzenmeier3 were simple, but subsequent investigations, aiming to improve the test and eliminate error, have introduced numerous new technics. Various types of anticoagulants, and tubes varying in length and bore, have been used. Much has been written concerning the importance of frequent readings or measurements, and various plans for charting readings have been devised. The advisability