During the Franco-Prussian War in 1870-71, the German soldiers were all vaccinated, and only a part of the French army was vaccinated. Smallpox broke out in the two armies. As a result, 6,000 of the French died from smallpox and only 278 of the Germans. In many instances, the German and the French soldiers were confined in the same hospitals, with exactly the same opportunities to contract the disease. But, you might ask, if vaccination prevents smallpox, how did it happen that there were _any_ cases among the German soldiers? In order to prevent smallpox, vaccination must be successful; that is, it must "take." We will tell you about different kinds of vaccination a little later. [Illustration: FIG. 62. In Sweden, before vaccination, smallpox caused 2,050 deaths per million population (represented by the large square). Since the introduction of vaccination the death rate has dropped to 2 per million population (represented by the two small squares).] [Sidenote: (_2_) In Sweden] In Sweden we find strong evidence that vaccination prevents smallpox. Up to 1801, before vaccination was introduced into that country, the yearly death rate from smallpox was 2,050 out of each million of the population. In 1801 vaccination was introduced into Sweden, but the people were allowed to be vaccinated or not, just as they pleased. During the ten years ending with 1811, the annual death rate from smallpox had dropped from 2,050 per million of the population to 686 per million. Later, vaccination was made compulsory (that is, everybody in Sweden was obliged to be vaccinated), and in 1894 the death rate had dropped to only two deaths a year per million population. Is it merely a coincidence that this great falling off in deaths from smallpox came after vaccination was discovered, or was it due to vaccination? [Sidenote: (_3_) In the Philippine Islands] Before the Philippine Islands were occupied by the Americans, vaccination was very little practiced, and a large percentage of the deaths in those islands was caused by smallpox. In 1897 smallpox caused about 40,000 deaths. A few years later the Americans enforced vaccination among the inhabitants of the Philippines, and the result was that in 1907 there were only 304 deaths from smallpox. There has been practically no quarantine for smallpox and no disinfection; the only cause of the suppression of the disease in the Philippine Islands is vaccination--nothing else. [Sidenote: (_4_) In Gloucester, England]