In recent years, bacteriologists have made important contributions to the etiology of arthritis, especially in regard to the part played by focal infections. The large mass of evidence which has gradually accumulated indicates that most cases of arthritis are infectious in origin. In spite of this, however, some practitioners have held to the belief that arthritis, particularly in its chronic form, is an expression of a disturbance in metabolism. The relationship between gouty arthritis and an abnormal purin metabolism gave some ground for this theory, and for many years the various forms of acute and chronic arthritis were supposed to be dependent on the retention in the body of uric acid or some kindred substance. For this reason rheumatic patients were often put on a reduced nitrogenous diet, but the results obtained by this mode of treatment were not encouraging. Pemberton1 has advocated a lowered carbohydrate intake for arthritis patients.