It must not be thought, however, that it was only with the coarse applications of surgery that Chauliac concerned himself. He was very much interested in the surgical treatment of eye diseases and wrote a monograph on cataract, in which he gathers what was known before his time and discusses it in the light of his own experience. The writing of such a book is not so surprising at this time if we recall that in the preceding century the famous Pope John XXI, who had been a physician before he became Pope, and under the name of Peter of Spain was looked up to as one of the distinguished scientists of his time, had written a book on eye diseases that has recently been the subject of much attention. Pope John had much to say of cataract, dividing it into traumatic and spontaneous, and suggesting the needling of cataract, a gold needle being used for the purpose. Chauliac's method of treating cataract was by depression. His care in the selection of patients may be appreciated from his treatment of John of Luxembourg, King of Bavaria, blind from cataract, who consulted Chauliac in 1336 while on a visit to Avignon with the King of France. Chauliac refused to operate, however, and put off the King with dietary regulations. In the chapter on John of Arcoli and Medieval Dentistry we call attention to the fact that Chauliac discussed dental surgery briefly, yet with such practical detail as to show very clearly how much more was known about this specialty in his time than we have had any idea of until recent years. He recognized the dentists as specialists, calls them dentatores, but thinks that they should operate under the direction of a physician--hence the physician should know much about teeth and especially about their preservation. He enumerates instruments that dentists should have and shows very clearly that the specialty had reached a high state of development. A typical example of Chauliac's common sense and dependence on observation and not tradition is to be found in what he has to say with regard to methods of removing the teeth without the use of extracting instruments. It is characteristic of his method of dealing with traditional remedies, even though of long standing, that he brushes them aside with some impatience if they have not proved themselves in his experience. "The ancients mention many medicaments, which draw out the teeth without iron instruments or which make them more easy to draw out; such as the milky juice of the tithymal with pyrethrum, the roots of the mulberry and caper, citrine arsenic, aqua fortis, the fat of forest frogs. But these remedies promise much and accomplish but little--_mais ils donnent beaucoup de promesses, et peu, d'operations_."