This, as the subtitle indicates, is a statement of the fundamental principles of diet for the mutual use of physicians and patients. As a statement of principles for physicians, it leaves nothing to be desired; it is interestingly written and easily read. We fail to see how it can be of great service to patients. They cannot well separate principles from practice; for them a book on normal diet should contain instructions on how to construct such a diet. A simple statement of principles is of little practical assistance to the patient.