RENAL FUNCTION TESTS
For many years the study of nephritis has attracted a great deal of attention from clinicians. The problems involved are so complicated and so many, the correlation of different anatomic lesions with variations in functional capacity is so difficult, and the stages through which any given case of nephritis may pass are sometimes so varied in the pictures they present, that it is indeed impossible for anyone to feel that he understands nephritis, no matter how much experience he may have had with it. Up to ten or twelve years ago the problem that chiefly interested investigators was a study of the histologic changes produced in the kidney tissue by different types of nephritis, and little attention was paid to changes in the functional capacity of the organ. At present the reverse is true, and studies in kidney function dominate the literature on nephritis in the last