Nutrition now occupies the center of the stage. Formerly she played only a minor, somewhat unattractive, role and her lines were few, but today she enjoys a leading part and has the spotlight. Still greater brilliance of performance is promised. This advancement began about a quarter of a century ago when man's imagination was fired and his zeal for scientific inquiry kindled by the discovery that certain hitherto unknown substances, later called vitamins, although required only in minute amounts, are absolutely essential to the orderly progress of an animal's life processes. Without these substances the young fail to grow and the older animal sickens. It is of this sickness, in its many forms, that I wish to speak.
Three facts concerning nutritive failure are becoming increasingly obvious: first, that it does not come solely from lack of vitamins but from deficiency of proteins and minerals as well; in certain of