This brief but comprehensive work embraces the main guiding principles for the therapeutic use of insulin in diabetes mellitus, and in nondiabetic conditions, such as toxemias of pregnancy, postoperative acidosis, and cyclic vomiting of children, in which it is desirable to aid the utilization of sugar by the tissues. In addition, the book contains a short outline of the history of insulin, its possible mode of action, the indications and contraindications for its use, and its limitations and dangers. There are presented methods for treating diabetes with and without insulin. After reviewing other procedures, the author discusses his own method. This depends considerably on numerous laboratory tests and, perhaps, is too intricate for routine use.