The studies have been carried on for eight years. They fall into two groups, chemical and clinical. The chemical work was done under the supervision of Dr. Chi Che Wang with the technical assistance of Miss Agnes A. Wood. All cow's milk was boiled one minute. The babies were normal infants more than 2 weeks of age, kept in a separate nursery, with special nursing provided by the hospital administration and the training school. Thus the infants escaped most of the parenteral infections so prevalent in any infants' ward. Experiments were never carried on when the babies were losing weight or seemed sick in any way. PURPOSE OF THE WORK According to the early theories of Finkelstein and L. F. Meyer, a diet containing excessive carbohydrate in cow's milk favored the development of diarrhea and nutritional disturbance. The mechanism was simple. Bacteria normally present in the intestine fermented the carbohydrate