804 the Hippocratic doctrine of humours, but developed with marvellous and fatal ingenuity. The normal condition or temperament of the body depended upon a proper mixture or proportion of the four elements hot, cold, wet, and dry. From faulty proportions of the same arose the intemperies (" distempers "), which, though not diseases, were the occasions of disease. Equal importance attached to faulty mixtures or dyscrasiae of the blood. By a combin ation of these morbid predispositions with the action of deleterious influences from- without all diseases were pro duced. Galen showed extreme ingenuity in explaining all symptoms and all diseases on his system. No phenomenon was without a name, no problem without a solution. And, though it was precisely in his fine-spun subtlety that he departed farthest from scientific method and practical utility, it was this very quality which seerns in the end to have secured his popularity and established his pre-eminence in the medical world. Galen s use of drugs was influenced largely by the same theories. In drugs were to be recognized the same elementary qualities hot, cold, moist, dry, itc.- as in the human body ; and, on the principle of curing by contraries, the use of one or other was indicated. The writings of Galen contain less of simple objective observation than those of several other ancient physicians, all being swept into the current of dogmatic exposition. But there is enough to show the thoroughness and extent of his practical knowledge. Unfortunately it was neither this nor his zeal for research that chiefly won him followers, but the com- pleten3ss of his theoretical explanations, which fell in with the mental habits of succeeding centuries, and were such as have flattered the intellectual indolence of all ages. But the reputation of Galen grew slowly ; he does not appear to have enjoyed any pre-eminence over other physicians of his time, to most of whom he was strongly opposed in opinion. In the next generation he began to be esteemed only as a philosopher ; gradually his system was implicitly accepted, and it enjoyed a great though not exclusive predominance till the fall of Iloman civilization. When the Arabs possessed themselves of the scattered remains of Greek culture, the works of Galen were more highly esteemed than any others except those of Aristotle. Through the Arabs the Galenical system found its way back again to Western Europe. Even when Arabian medi cine gave way before the direct teaching of the Greek authors rescued from neglect, the authority of Galen was increased instead of being diminished ; and he assumed a position of autocracy in medical science which was only slowly under mined by the growth of modem science in the 17th and 18th centuries. But the history of medicine in Roman times is, by no means the same thing as the history of the fate of the works of Galen. For some centuries the methodic school was popular at Rome, and produced one physician, Coelius Aurelianus, who must be pronounced, next to Celsus, the most considerable of the Latin medical writers. His date was in all probability the end of the 4th or beginning of the 5th century, The works bearing his name are, as has been said, entirely based upon the Greek of Soranus, but are important both because their Greek originals are lost, and because they are evidence of the state of medical practice in his own time. The popularity of Ccelius is evidenced by the fact that in the 6th century an abridf- inent of his larger work was recommended by Cassiodorus to the Benedictine monks for the study of medicine. Before quitting this period the name of Aretams of Cappadocia must be mentioned. So little is known about him that even his date cannot be fixed more closely than as being between the second half of the 1st century and the beginning of the 3d. His works have been much [HISTORY. admired for the purity of the Greek style, and his accurate descriptions of disease ; but, as he quotes no medical author, and is quoted by none before Alexander of Aphrodisias at the beginning of the 3d century, it is clear that he belonged to no school and founded none, and thus his position in the chain of medical tradition is quite uncertain. Alexander of Aphrodisias, who lived and wrote at Athens in the time of Septimius Severus, is best known by his commentaries on Aristotle, but also wrote a treatise on fevers, still extant. Ancient Medicine after Galen. The Byzantine school of medicine, which closely corresponds to the Byzantine literary and historical schools, followed closely in Galen s footsteps, and its writers were chiefly compilers and ency clopaedists. The earliest is Oribasius (326-403), whose date and position are fixed by his being the friend and court physician of Julian the Apostate. He was a Greek of Pergamum, educated in Alexandria, and long resident in Byzantium. His great work Swaywyai iarpiKai, of which only about one-third has been preserved, was a medical encyclopaedia founded on extracts from Hippo crates, Galen, Dioscorides, and certain Greek writers who are otherwise very imperfectly known. The wcrk is thus one of great historical value but of no originality. The uexfe name which requires to be mentioned is that of Aetius (550 A.D. ), a compiler who closely followed Oribasius, but with inferior powers, and whose work also has an historical but no original value. A higher rank among medical writers is assigned to Alexander of Tralles (525-605), whose doctrine was that of an eclectic. His practical and therapeutical rules are evidently the fruit of his own experience, though it would be difficult to attribute to him any decided advance in medical knowledge. But the most prominent figure in Byzantine medicine is that of Paul of TEgina (Paulus yEgineta), who lived probably in the early part of the 7th century. His skill, especially in surgery, must have been considerable, and his JarpiKu gives a very complete picture of the achievements of the Greeks in this department. Another work, on ob stetrics, now lost, was equally famous, and procured for him, among the Arabs, the name of "the Obstetrician." His reputation lasted through the Middle Ages, and was not less in the Arabian schools than in the West. In this respect Paulus is a most important in fluence in the development of medicine. His great work on surgery was early translated into Arabic, and became the foundation of the surgery of Abulcasis, which in turn (to anticipate) was one of the chief sources of surgical knowledge to Europe in the Middle Ages. The succeeding period of Byzantine history was so little favourable to science that no name worthy of note occurs again (though many medical works of this period are still extant) till the 13th century, when we meet with a group of writers ; Demetrius Pepagomenus, Nicolaus Myrepsus, and Johannes, called Actuarius, w ; ho flourished under the protection of the Paheologi. The work of the last has some independent merit ; but all are interesting as showing a fusion of Greek and Arabian medicine, the latter having begun to exercise even in the llth century a reflex influence on the schools of Byzantium. Something was borrowed even from the school of Salerno, and thus the close of Byzantine medicine is brought into connexion with the dawn of science in modern Europe. In the West the period after Galen affords little evidence of anything but a gradual though unvarying decline in Roman medicine. Ccelius Aurelianus, already referred to as the follower of Soranus, must be mentioned as showing the persistence of the methodic school. An abridgment of one of his writings, with the title of Aurelius, became the
most popular of all Latin medical works. As a writer he