CHAPTER XXVI 

 PLAGUE 



Bacillus Pestis (Yersin, Kitasato) 



General Characteristics. — A minute, pleomorphous, diplococcoid and elongate, 

 sometimes branched, non-motile, non-flagellated, non-sporogenous, non-liquefy- 

 ing, non-chromogenic, non-aerogenic, aerobic, and optionally anaerobic, patho- 

 genic organism, easily cultivated artificially, and susceptible of staining by 

 ordinary methods, but not by Gram's method. 



Plague, bubonic plague, pest, black plague, black death, or 

 malignant polyadenitis is an acute epidemic infectious febrile 

 disease of an intensely fatal nature, characterized by inflammatory 

 enlargement and softening of the lymphatic nodes, marked pul- 

 monary, cerebral and vascular disturbance, and the presence of the 

 specific bacillus in the lymphatic nodes and blood. 



The history of plague is so full of interest that many references 

 to it appear in popular literature. The student can scarcely find 

 more profitable reading than the "History of the Plague Year in 

 London," by DeFoe, and readers of Boccaccio will remember that 

 it was the plague epidemic then raging in Florence that led to the 

 isolation of the group of young people by whom the stories of 

 the Decameron were told. 



During the reign of the Emperor Justinian the plague is said 

 to have carried off nearly half of the population of the Roman Em- 

 pire. In the fourteenth century it is said to have destroyed nearly 

 twenty-five millions of the population of Europe. Epidemics of 

 less severity but attended with great mortality appeared in the • 

 sixteenth, seventeenth, and eighteenth centuries. In 1894 an 

 epidemic broke out in the western Chinese province of Yunnan 

 and reached Canton in January, 1894, thus escaping from its en- 

 demic center and began to spread. It can be traced from Canton 

 to Hongkong. In 1895 it appeared also in Amoy, Macao, and 

 Foochoo. In 1896 it had reached Bombay and reappeared in Hong- 

 kong. In 1897 Bombay, the Madras Presidency, the Punjab, and 

 Madras were visited. In 1898 the disease spread greatly through- 

 out India and into Turkestan, and by sea went to Madagascar and 

 Mauritius. In 1899 it extended still more widely in India and 

 China, Japan and Formosa, and succeeded in disseminating as 

 widely as the Hawaiian Islands and New Caledonia on the east, 

 Portugal, Russia, and Austria on the west, and Brazil and Para- 

 guay on the south. In 1900 it had spread to nearly every part of 

 the world. In those places in which sanitary measures could not be 

 carried into effect the people died in great numbers — thus in India 



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