Another of the great divisions of the healing art, that of midwifery, has been enhanced quite as much as general surgery by the employment of Listerism. The process of childbirth, although a perfectly natural one, almost necessarily carries with it a certain amount of laceration, and, through the wound surfaces thus produced, absorption of poisonous material was formerly so frequent that puerperal fever figured prominently in mortality reports. It was Oliver Wendell Holmes--a graduate in medicine and a professor in the Harvard Medical School, though we are accustomed to think of him only as a delightful writer--who first declared that puerperal fever was the product of infection from without the body, and Semmelweis demonstrated the truth of the proposition. Holmes was a teacher of physiology, and his study of that branch of medical science was in itself enough to convince him of the doctrine which he inculcated. Listerism must be credited, not only with having added immensely to the safety of the major operations of surgery, but also with having led to great improvement of their technics by reason of the greatly increased frequency with which it has come to be thought justifiable to practise them; what we do again and again we are apt in the end to do well, whereas that which we turn to only in despair and as rarely as possible, we do clumsily and imperfectly. Listerism has been unjustly alleged by a few to be unworthy of the appreciation in which it is held by the great majority of medical men of all countries; simple cleanliness, it has been urged, is quite as efficient as the full Listerian precautions. This is begging the question, for simple cleanliness, "chemical cleanliness," is all that Listerism purports to accomplish. The use of antiseptics has been decried in the interest of asepticism, as if the whole purpose of antisepticism were not to secure asepsis. Lord Lister is entitled to the full credit of establishing the aseptic surgery of the present day, in spite of the facts that his doctrine followed rather than preceded his early improvements, that aseptic procedures have been brought nearer perfection elsewhere than in his own country, and that the whole system rests on foundations laid by Pasteur.