316 BACTERIOLOGY. 



characterized by suppuration of the lymphatic glands, 

 and accompanied by a very high rate of mortality. 



This pestilence, probably endemic in certain sections 

 of the Orient, is one of the most conspicuous epidemic 

 diseases of history. Since early in the Christian era epi- 

 demics and pandemics of plague have made their appear- 

 ance in Europe at different times. During and for a time 

 after the Middle Ages it was more or less frequent in 

 India, China, Arabia, Northern Africa, Italy, France, 

 Germany, and Great Britain. In history it is variously 

 known as the " Justinian Plague " of the sixth century, 

 the " Black Death " of the fourteenth century, and the 

 " Great Plague of London " of the seventeenth century, 

 though it is difficult to say to what extent these pesti- 

 lences were uncomplicated manifestations of genuine 

 bubonic plague. During the existence of the Justinian 

 Plague 10,000 people are said to have died in Con- 

 stantinople in a single day, and Hecker estimates that 

 during the pandemic of the Black Death 25,000,000 

 people (a quarter of the entire population of Europe) 

 succumbed to the disease. During the Great Plague 

 of London (1664-'65) the total mortality for one year 

 was 68,596, out of an estimated population of 460,000 

 souls. 



It is not surprising to learn that it was to guard 

 against the plague that quarantine regulations were 

 first established. 



The first and certainly the most exact information 

 up to date concerning the cause and pathology of the 

 plague resulted from the investigations of Yersin, of 

 Kitasato, and of Aoyama, conducted during the epi- 

 demic of 1894 in Hong-Kong, China; although since 

 then numerous other investigators have made addi- 



