The advances made in this branch of Surgery have long since translated it from the realm of empiricism to the field of rationalism. Treatment based primarily on the results of experience or observation must give place to a system based upon a knowledge of abnormal conditions and the resultant changes in the tissues. Such knowledge elicits treatment directed definitely against these processes. It is obvious that this can be accomplished only through the agency of certain definite manual and therapeutic measures, the physiologic actions of which are well understood and known to be reliable. Much stress has been laid upon the subject of asepsis and antisepsis. The foot is peculiar in that conditions surrounding it are especially congenial to the development and multiplication of bacteria. Modern surgery has been built upon the recognition of the rôle of bacteria in the behaviour of wounds, and the greatest hazard to successful surgery lies in the ever-present possibility of bacterial invasion. Surgical safety, however, can be secured by the employment of a perfect technic for asepsis. Once the precept is established that the operative field must be asepticized and thereafter protected from contact with any septic object, the status of Podiatry will be secure for all time. Should we accomplish this, these pages will have served a purpose. Two notable features of the present volume are a comprehensive glossary and an exhaustive index which greatly enhance its usefulness, enabling the reader to find references to the subject before him, and with very little inconvenience to learn the meanings of unfamiliar words, thus obviating the necessity for a medical dictionary. We avail ourselves of this opportunity to acknowledge our gratitude to Dr. Maurice J. Lewi for his assistance in editing and in publishing our work in keeping with his estimate of its possible field of usefulness. M. S. E. A. CHAPTER I +INTRODUCTION+ Surgery, in contradistinction to medicine, as a separate branch of the healing art, includes all manual procedures and is not limited to cutting operations exclusively. It is that branch which deals with the treatment of morbid conditions by means of manual or instrumental agencies. Morbid conditions include three distinct classes: those due to 1. Injuries 2. Infections 3. Diseases +Injuries.+ To this class belong all the processes due to physical agencies and it includes besides traumatism, the effects of heat and cold, of chemicals, of light and of electricity. +Infections.+ These may be either local or general. The reaction might occur at the point of entrance of the bacteria, or constitutional symptoms may evidence their invasion into the blood, or the absorption of their toxic products. Many conditions in this class are linked closely with those in the following class: