"Toxemic theories, to account for the origin of functional nervous disorders, have had a great fascination for physicians of our generation." While physiologic chemistry is the science to which medicine will next look for guidance, it is very evident that even the chemists are yet groping in the dark and that the boundaries of our ignorance are just beginning to be defined. The symptoms of uremia are not due to urea; in spite of Haig's ingenious speculations, which seem to appeal to many, the symptoms of lithemia are not from the uric acid, and Putnam and Pfaff,1 from whom the above is taken, show that the paraxanthin theory of migraine, epilepsy and asthma is equally groundless. The laborious investigations of Pfaff, of the urine of five epileptics, controlled by the examination of 5000 liters of normal urine, failed to corroborate Ratchford's claim that paraxanthin, which is normally present in