It has recently been possible to study in great detail a patient with diabetes who showed, six weeks after an acute onset, symptoms of maximum severity. This was followed by marked improvement under treatment, and within two months he was able to tolerate 160 gm. of carbohydrate on a mixed diet of 3,000 calories without hyperglycemia or the appearance of sugar or acetone bodies in the urine. It is the purpose of this paper to give a brief summary of the more important observations.1 The points of particular interest in regard to this case are: Excessive protein waste over a long period of time. Complete inability to oxidize sugar, including all of the sugar formed from the protein molecule. Extreme acidosis, increasing during the first fast. The fat metabolized by the patient was practically all used in the formation of beta-oxybutyric acid. Low respiratory quotient rising when the blood