146 INFECTION AND. IMMUNITY 



diseases had a share in contributing to the mortality 

 statistics of Europe and Asia during the Middle Ages 

 and in earlier times. 



Relapsing fever prevailed in Ireland and in Scot- 

 land during the years 1799-1800, 1817-19, 1826- 

 27, 1842-48, and in the last year (1848) it invaded 

 several of the larger towns of England. In 1868- 

 70 it again prevailed in England and Scotland, and 

 cases are reported to have occurred in London as 

 recently as the year 1873. On the Continent the first 

 accounts we have come from Russia Odessa, in 

 1833; Moscow, 1840-41. In the autumn of 1863 

 the disease reappeared in Odessa ; the following year 

 it became epidemic over extensive areas in Russia, 

 and extended to Livonia and Finland (1865), to Si- 

 beria (1866), and to Poland (1868). According to 

 Hirsch, the disease continued to prevail in Russia 

 over extensive areas during subsequent years, and 

 was observed among the Russian troops as late as 

 1878-79. In Germany an extensive epidemic broke 

 out in 1868, as a result of importation from Russia. 

 A second, more restricted, epidemic occurred in 

 1871-72, and a third in 1878-79. In the west and 

 south-west of Europe Switzerland, France, Italy, 

 Spain the disease is as yet unknown. In India re- 

 lapsing fever has, no doubt, prevailed for many years, 

 but the differential diagnosis between it and remit- 



