The course that uric acid ( urate ) follows through the kidney has been the object of investigation since the development of techniques of the study of this function. The best evidence advanced a generation ago, in the golden age of physiology, suggested that plasma uric acid is completely filtered through the glomerular membrane, that a significant proportion of the filtered substance is reabsorbed by the tubules, and that none is excreted through active enzymatic mechanisms or by differences in osmotic pressure between the tubules and circulating blood. A. N. Richards, of the University of Pennsylvania School of Medicine, and Homer W. Smith, of New York University College of Medicine, were staunch proponents of this mechanism. Their conclusions were supported by the best experimental data available at that time produced by the best techniques that had been devised.
It was important to place reliance on a sound concept of the mechanism of