Besides hospitals, a series of lazarettos--that is, of buildings for the segregation of lepers--were erected in the various countries of Europe during the medieval period. Just about the end of the Crusades it was discovered that leprosy had become very common throughout Europe. It is often said that leprosy was introduced at this time, but it had evidently been in the West for many centuries before. Gregory of Tours mentions leper hospitals as early as 560, and the disease evidently continued to progress, in spite of these special hospitals, until in the thirteenth century it became clear that strenuous efforts would have to be made to wipe out the disease. Accordingly, leproseries were erected in connection with practically every town in Europe at this time. Baas estimates that there were some 19,000 of them in Europe altogether. Virchow has listed a large number of the leper hospitals of the German cities, quite enough to show that probably no organized community was without one. As a consequence of this widespread movement of enforced segregation, leprosy gradually died out in Europe, remaining only here and there in backward localities. The disease was probably as common during the later Middle Ages as tuberculosis is among us at the present time. The recently discovered relations between the bacterial cause of the two diseases may give rise to the question as to whether we shall succeed as well with the great social and hygienic problem that confronts our generation, of lowering the death-rate from "the great white plague," as the medieval generations did with their chronic folk-disease, leprosy. It would be "a consummation devoutly to be wished." We are now beginning to have as many sanatoria for tuberculosis in proportion to the population as they had of leproseries. These leproseries, or lazarettos, as they were called, were not at all the dreadful places that the imagination has been wont to picture them in recent years; on the contrary they were, as a rule, beautifully situated on a side-hill to favour drainage, consisted of a series of dwellings with a chapel in their midst surrounded by trees, and encompassed by what was altogether a park effect. Miss Clay, in "Medieval Hospitals," has given a picture of one of them, which we reproduce, because it serves to contradict the popular false notion with regard to the bare and ugly and more or less jail-like character of these institutions. CHAPTER XI MEDIEVAL CARE OF THE INSANE