INTRODUCTION
Despite the many excellent studies on the use of insulin in diabetes, there has, as yet, been evolved no satisfactory routine method of regulating the dosage and the time of its administration. It is obviously to be desired that the doses be as small and the administrations as infrequent as possible. Moreover, with a diet adequate for maintenance and reasonable activity, the blood sugar concentration throughout the day must be held within normal limits. To accomplish this requires, first, an appreciation of what the normal blood sugar values throughout the day are and, second, an understanding of the effects that various diets and insulin dosages, and certain combinations of these, produce in diabetic patients. Only by intensive studies of the blood sugar concentration on large numbers of both normal persons and those in differing stages of the disease, can this knowledge be obtained. Our purpose, in this paper, is