Gurlt says ("Geschichte der Chirurgie," Vol. I, p. 703) that "in spite of the fact that there is some doubt about the names of the authors, this volume constitutes one of the most important sources for the history of surgery of the later Middle Ages and makes it very clear that these writers drew their opinions from a rich experience." It is rather easy to illustrate from the quotations given in Gurlt or from the accounts of their teaching in Daremberg or De Renzi some features of this experience that can scarcely fail to be surprising to modern surgeons. For instance, what is to be found in this old text-book of surgery with regard to fractures of the skull is likely to be very interesting to surgeons at all times. One might be tempted to say that fewer men would die every year in prison cells who ought to be in hospitals, if the old-time teaching was taken to heart. For there are rather emphatic directions not to conclude because the scalp is unwounded that there can be no fracture of the skull. Where nothing can be felt care must be exercised in getting the history of the case. For instance, if a man is hit by a metal instrument shaped like the clapper of a bell or by a heavy key, or by a rounded instrument made of lead--this would remind one very much of the lead pipe of the modern time, so fruitful of mistakes of diagnosis in head injuries--special care must be taken to look for symptoms in spite of the lack of an external penetrating wound. Where there is good reason to suspect a fracture because of the severity of the injury, the scalp should be incised and a fracture of the cranium looked for carefully. That is carrying the exploratory incision pretty far. If a fracture is found the surgeon should trephine so as to relieve the brain of any pressure of blood that might be affecting it. There are many warnings, however, of the danger of opening the skull and of the necessity for definitely deciding beforehand that there is good reason for so doing. How carefully their observations had been made and how well they had taken advantage of their opportunities, which were, of course, very frequent in those warlike times when firearms were unknown, hand-to-hand conflict common, and blunt weapons were often used, can be appreciated very well from some of the directions. For instance, they knew of the possibility of fracture by _contrecoup_. They say that "quite frequently though the percussion comes in the anterior part of the cranium, the cranium is fractured on the opposite part."[18] They even seem to have known of accidents such as we now discuss in connection with the laceration of the middle meningeal artery. They warn surgeons of the possibilities of these cases. They tell the story of "a youth who had a very small wound made by a thrown stone and there seemed no serious results or bad signs. He died the next day, however. His cranium was opened and a large amount of black blood was found coagulated about his dura mater."