Giovanni of Vigo is very brief in speaking on the treatment of dental caries, doubtless because he attributed little or no value to the numerous methods of cure recommended by his predecessors. The treatment advised by him is, however, very noteworthy. He says that by means of a drill, file, scalpel, or other suitable instrument, it is necessary to remove the whole of the putrefied or corroded part of the teeth, and then, to preserve it, to fill the cavity with gold leaf. This clear and simple manner of speaking of gold filling as a cure for caries makes us suppose that Giovanni of Vigo was not at all a stranger to the practice of dentistry, as we must think of many preceding writers, but, on the contrary, that he was not less skilled in dental operations than he was in the other branches of surgery. Again, history tells us that Giovanni of Vigo was surgeon to the Roman court; so it would have been strange, indeed, if the Pope, if the haughty prelates, accustomed as they were to all kinds of refinement and comfort, should have intrusted the care of their teeth to lowborn barbers and quacks, whilst they could dispose of the services of so eminent a surgeon. It may, however, be seen from the very book of Giovanni of Vigo,[269] that in his days doctors and surgeons were, in general, little skilled in dental matters. Speaking of the extraction of teeth, he says: “For this operation there is need of a practised man, and, therefore, many medical and surgical authorities have expressed an opinion that this operation should be left to expert barbers and to the itinerant quacks who operate in public places. He, therefore, who desires to perform this manual operation in the best manner will derive great advantage by frequenting men who are expert in performing it and by seeing and impressing well on his memory their manner of operating.”[270] PART III. THIRD PERIOD—MODERN TIMES. CHAPTER X. THE SIXTEENTH CENTURY. We have now arrived at the sixteenth century. The middle ages, that is, the period of transition between ancient and modern civilization, has now come to an end. Events of the highest importance, such as the invention of printing (1436), the taking of Constantinople by the Turks (1453), with the consequent emigration of many Greek men of letters and science, who took up their residence in the West and especially in Italy, and lastly, the discovery of America (1492), marked the beginning of a new era, and are the most essential factors in bringing about the revival of art and science. In the midst of the vigorous intellectual life which characterized the sixteenth century, dentistry, too, like many other branches of science, made very notable progress; we, therefore, in this period shall have to record many important facts and many important names.