PREVENTIVE MEDICINE. 351 



was about 40,000. The disease also extended westward from Con- 

 stantinople through Austria and Bohemia. 



In 1720 Marseilles suffered a severe epidemic, probably as a result 

 of the introduction of cases on a ship from Leghorn. The mortality 

 was estimated as being between 40,000 and 60,000. From Marseilles as 

 a center it spread through the province of Provence, but did not invade 

 other parts of France. In 1743 a severe outbreak occurred on the 

 island of Sicily. A destructive but brief epidemic, which is estimated 

 to have caused a mortality of 300,000, occurred during the years 1770 

 and 1771 in Moldavia, Wallachia, Transylvania, Hungary and Poland. 

 At the same time the disease prevailed in Eussia, and in 1771 caused 

 the death of about one fourth of the population of the city of Moscow. 



Early in the nineteenth century (1802) bubonic plague appeared 

 at Constantinople and in Armenia. It had previously prevailed in the 

 Caucasus, from which province it extended into Russia. In 1808 to 1813 

 it extended from Constantinople to Odessa, to Smyrna and to various 

 localities in Transylvania. It also prevailed about the same time in 

 Bosnia and Dalmatia. In 1812 to 1814 it prevailed in Egypt, and, as 

 usual, was conveyed from there to European countries. During the 

 same year it prevailed extensively in Moldavia, Wallachia, and Bessa- 

 rabia. In 1831 it again prevailed as an epidemic in Constantinople 

 and various parts of Roumelia, and again it appeared in Dalmatia in 

 1840 and in Constantinople in 1841. Egypt, which for centuries had 

 been the principal focus from which plague had been introduced into 

 Europe, continued to suffer from the disease until 1845 when it dis- 

 appeared from that country. 



The last appearance of oriental plague in Europe, until its recent 

 introduction into Portugal, was the outbreak on the banks of the Volga 

 in 1878-79. The disease had previously prevailed in a mild form in 

 the vicinity of Astrakhan and was probably introduced from that 

 locality. An interesting fact in connection with this epidemic is that in 

 Astrakhan the disease was so mild that no deaths occurred, and that the 

 earlier cases on the right bank of the Volga were -of the same mild 

 form, but that the disease there increased rapidly in severity and soon 

 became so malignant that scarcely any of those attacked recovered. 

 This is to some extent the history of epidemics elsewhere, and not only 

 of plague, but of other infectious diseases, such as typhus fever, cholera 

 and yellow fever. In all of these diseases the outset of an epidemic may 

 be characterized by cases so mild in character that they are not recog- 

 nized, and during the progress of the epidemic many such cases may 

 continue to occur. These cases are evidently especially dangerous as 

 regards the propagation of the disease, for when they are not recognized 

 no restrictions are placed upon the infected individuals, although they 

 may be sowing the germs broadcast. 



