This little book, which can easily be read in an hour, presents the substance of a popular lecture recently delivered at the Harvard Medical School. Since the book is intended for laymen, its language is not technical. It should prove instructive to intelligent patients who have nephritis or to parents of afflicted children. Dr. Ohler considers only the common forms of "Bright's disease": that attributable to inflammation or to bacterial invasion and that attributable to degeneration or sclerosis of small arteries. Comments are made on the structure and function of the kidneys, the nature of normal and abnormal urine, the scope of Bright's disease and its course, and uremic poisoning and dropsy. Also briefly discussed are diet and dietary management, Bright's disease in pregnancy, and the treatment of acute and chronic nephritis.