_Books on diabetes for patients._--Doctor Joslin’s “Diabetic Manual,” Lea and Febiger, is one of these. Doctor Petty’s “Diabetes, Its Treatment by Insulin and Diet,” F. A. Davis Company, Philadelphia, is another. Wilder, Foley and Ellithorpe’s “A Primer for Diabetic Patients,” W. B. Saunders Company, Philadelphia, may be consulted for more complete descriptions of the methods employed in the Mayo Clinic than can be given here. _Patients must be trained._--The results of accurate management are so encouraging that they are almost as good as cures. They are not cures, because the fundamental island weakness is rarely if ever completely corrected, and treatment must continue for month after month. Success, therefore, rests largely in the patient’s hands and the doctors’ most important task is teaching the patient all that he can be taught about his diet and about the use of insulin. The books mentioned were written to help in this training of patients. In various clinics over the country, patients attend classes and are instructed in the subject of dietetics until they can weigh food and plan meals accurately so that each will contain a set number of calories and yield to the metabolism a predetermined amount of sugar. The hospital management of a case of diabetes is not complete until the patient can live a healthy life in spite of his disease. He may arrive at the hospital in a state of coma and be dragged from the very jaws of death with insulin, but afterwards, when he goes home, unless he has learned how to continue the use of insulin and combine with it an accurate diet, he will slip again into the same dangerous predicament. It is best always to start treatment in a hospital where a systematic course of instruction can be obtained. Unfortunately, we have no schools for diabetic patients other than the hospitals, and some persons dislike hospitals. Good results can be obtained at home, provided one has the good fortune to consult a physician who will take the time to give this training. What are the essentials? _What the patient must know._--First, a knowledge of how to read food tables and, with their aid, to plan accurate diets. Food tables are lists of foods showing the composition of each, in protein, carbohydrate and fat. The books mentioned here all contain such lists. The most complete table is that published by the United States Department of Agriculture, Bulletin No. 28, “The Chemical Composition of American Food Materials,” a pamphlet that may be had from the Superintendent of Documents, Government Printing Office, Washington, D. C., for the small sum of ten cents. Second, instruction in the manner of injecting insulin, that is, in the use of the hypodermic syringe. Insulin, as has been stated, must be given hypodermically, under the skin. The technic is not difficult, but sterile precautions must be observed in order to avoid introducing disease germs with the insulin.