Richard Bright1 was well aware of the effects of prolonged albuminuria on the serum proteins, because he actually obtained quantitative analytic data with the help of friends who were chemists. He believed that the thin, watery plasma filtered out into the tissue spaces readily, thus producing dropsy. It is obvious that he considered renal edema as uniform in type and in causation. For almost a hundred years clinicians and physiologists failed to distinguish between the different forms of dropsy occurring in Bright's disease and sought to explain them all on a single basis. The experimental work on edema reflected accurately the prevailing clinical theories. Thus Bright's theory of hydremia as the cause of edema was put to the experimental test by Cohnheim and Lichtheim2 and found wanting. Similarly, the rôle of oliguria and hydremic plethora defended by Bartels3 and Grainger Stewart4 was more or less definitely