Düsseldorf │ │ │ │ │Oct. │ │ │ │ 981│Aug. 15│ 13│(1870) │ 6│ 524 Coblenz │Sep. 15 │15,011│Sep. 23│ 571│Nov. 2 │ 0│ 81 Cologne │Sep. 1 │13,774│Sep. 1 │ 175│Sep. 12│ 65│ 418 Wesel │Sep. 9 │16,299│Sep. 20│ 1,042│Nov. │ 9│ 84 The book contains a survey of the small-pox mortality in Prussia in the year 1871 according to Governmental Districts and Communities. The figures for the year 1872 have not been published; they were placed at my disposal, in manuscript form, by the Royal Prussian Bureau of Statistics. ────────────────────────────────────────────────────────────────────────── The small-pox mortality varied greatly in the different Prussian Governmental Districts; particularly noteworthy is the fact that it was considerably higher in the eastern provinces, especially in the year 1872, than in the western provinces, notwithstanding the fact that the latter were exposed to the infection much sooner and much more frequently in consequence of the arrival and passing through of French prisoners. The only plausible explanation of this is the fact that the inhabitants of eastern Prussia were not so thoroughly vaccinated as those in the west; this, however, was not because the anti-vaccinationists were more influential in the east, but because the eastern provinces had fewer physicians than the western provinces, where medical advice and help were far more accessible, and where the population was more enlightened. The effect of vaccination is clearly revealed in those Governmental Districts in the west which introduced compulsory vaccination before they were incorporated into Prussia; Schleswig-Holstein did this in 1811, Hanover in 1821, the Governmental District of Wiesbaden in 1820, and the Governmental District of Cassel in 1828. All these parts of the country had fewer cases of small-pox. The Governmental Districts in which large military prisons were located, and those in which, owing to a higher industrial development, there was more intercourse of all kinds, were attacked earlier by small-pox than the others. Of the western provinces only the two highly industrial districts of Arnsberg and Düsseldorf, and the district of Trèves, were very severely attacked. The living conditions among the working people were not so good at that time as they are to-day, and the close quarters must necessarily have favoured the dissemination of small-pox; furthermore, the constant moving about of the working inhabitants, many of whom did not live where they were employed, helped to spread it. Thus it was observed in the vicinity of Leipzig, that the villages inhabited by working people were much more severely attacked by small-pox than those inhabited by farmers, with their stationary and settled population. The high figures in the case of the Governmental District of Trèves may be explained by the fact