For our generation undoubtedly the most interesting chapter in the history of medieval medicine is that which tells of the marvellous development of surgery that took place in the thirteenth and fourteenth centuries. Considerable space has been devoted to this, because it represents not only an important phase of the history of medicine, and recalls the names and careers of great makers of medicine, but also because it illustrates exquisitely the possibility of important discoveries in medicine being made, applied successfully for years, and then being lost or completely forgotten, though contained in important medical books that were always available for study. The more we know of this great period in the history of surgery, the more is the surprise at how much was accomplished, and how many details of our modern surgery were anticipated. Most of us have had some inkling of the fact that anaesthesia is not new, and that at various times in the world's history men have invented methods of producing states of sensibility in which more or less painless operations were possible. Very few of us have realized, however, the perfection to which anaesthesia was developed, and the possibility this provided for the great surgeons of the later medieval centuries to do operations in all the great cavities of the body, the skull, the thorax, and the abdomen, quite as they are done in our own time and apparently with no little degree of success. Of course, any such extensive surgical intervention even for serious affections would have been worse than useless under the septic conditions that would surely have prevailed if certain principles of antisepsis were not applied. Until comparatively recent years we have been quite confident in our assurance that antisepsis and asepsis were entirely modern developments of surgery. More knowledge, however, of the history of surgery has given a serious set-back to this self-complacency, and now we know that the later medieval surgeons understood practical antisepsis very well, and applied it successfully. They used strong wine as a dressing for their wounds, insisted on keeping them clean, and not allowing any extraneous material of any kind, ointments or the like, to be used on them. As a consequence they were able to secure excellent results in the healing of wounds, and they were inclined to boast of the fact that their incisions healed by first intention and that, indeed, the scar left after them was scarcely noticeable. We know that wine would make a good antiseptic dressing, but until we actually read the reports of the results obtained by these old surgeons, we had no idea that it could be used to such excellent purpose. Antisepsis, like anaesthesia, was marvellously anticipated by the surgical forefathers of the medieval period.