In the latter half of the twelfth century lived John of St. Paul, one of the teachers of Gilbert the Englishman; also Musandinus, who left a curious treatise on dietetics; and Urso, who wrote on the pulse and on the urine. Here in 1190 resided and studied a certain Alcadinus, from Syracuse, whose knowledge of philosophy and medicine was such that he acquired great reputation, and was made a professor; he even composed Latin medical poems. Just at the close of this century flourished Ægidius, who studied{078} at Salernum, and also at Montpellier, where a school of medicine had been founded in 1180; he was physician to Philip Augustus, of France, and became professor in the University of Paris. Three treatises, all in Latin hexameter, are ascribed to him. A contemporary was Johanes Rogerus, of Palermo, a graduate of Salernum and author of several works. Early in the thirteenth century flourished Roger of Parma, one of the most distinguished of the alumni of this school and the earliest pioneer in modern surgery; his work on this topic, familiarly known as _Rogeriana_, enjoyed the greatest reputation in its day, and was for a long time the surgical text-book of Italy; his predilection for poultices and moist dressings in the treatment of wounds, abscesses, and ulcers became, in the hands of his successors, the distinguishing feature of the surgery of Salernum in opposition to the school at Bologna, where Hugo Di Lucca and Theo-doric (his great rival) contended for the superiority of the dry treatment. Roger was also the first to use the term _seton_, and to give practical demonstration to this means of derivation. Roland of Parma, a pupil of Roger, and a surgeon of great distinction, became professor at Bologna, and wrote a treatise on surgery, which was, for the most part, a commentary on the works of his master. The treatise of Roger and that of Roland furnished the basis for a work entitled _The Treatise of the Four Masters_, supposed to have been written about 1270, and manuscripts of which have been long known in various European libraries. It is divided into four books, displays no little surgical ability, and from its title would appear to have been the joint composition of four teachers; indeed, it was long attributed to Archimatheus, Platearius, Petro Cellus, and Affiacius, though it is now pretty generally understood to be the product of but a single pen and its author most likely a Frenchman. The ascription of authorship to four masters was probably for the purpose{079} of increasing its weight and authority, and it constituted a reliable exposition of the surgery of Salernum in its day. It is quoted quite freely by Guy de Chauliac, who was the restorer of French surgery in the fourteenth century, and occasionally by later writers.