That Arculanus' work with regard to dentistry was no mere chance and not solely theoretic can be understood very well from his predecessors, and that it formed a link in a continuous tradition which was well preserved we may judge from what is to be found in the writings of his great successor, Giovanni or John de Vigo, who is considered one of the great surgeons of the early Renaissance, and to whom we owe what is probably the earliest treatise on "Gun-shot Wounds." John of Vigo was a Papal physician and surgeon, generally considered one of the most distinguished members of the medical profession of his time. Two features of his writing on dental diseases deserve mention. He insists that abscesses of the gums shall be treated as other abscesses by being encouraged to come to maturity and then being opened. If they do not close promptly, an irritant Egyptian ointment containing verdigris and alum among other things should be applied to them. In the cure of old fistulous tracts near the teeth he employs not only this Egyptian ointment but also arsenic and corrosive sublimate. What he has to say with regard to the filling of the teeth is, however, most important. He says it with extreme brevity, but with the manner of a man thoroughly accustomed to doing it. "By means of a drill or file the putrefied or corroded part of the tooth should be completely removed. The cavity left should then be filled with gold leaf." It is evident that the members of the Papal court, the Cardinals and the Pope himself, had the advantage of rather good dentistry at John de Vigo's hands even as early as the beginning of the sixteenth century. John de Vigo, however, is not medieval. He lived on into the sixteenth century and was influenced deeply by the Renaissance. He counts among the makers of modern medicine and surgery, as his authorship of the treatise on gun-shot wounds makes clear. He comes in a period that will be treated of in a later volume of this series on "Our Forefathers in Medicine." XIII CUSANUS AND THE FIRST SUGGESTION OF LABORATORY METHODS IN MEDICINE