BUBONIC PLAGUE 139 



by 1 per cent carbolic acid in ten minutes; and 

 by corrosive sublimate solution 1 : 1000 instantly. 



Plague Infection in Man. — The first records of 

 plague in history date about the beginning of the 

 Christian era. For centuries it raged in Northern 

 Africa, and during the middle ages extended to 

 Arabia, India, Asia Minor, and throughout Europe. 



History relates that during the frightful visitation 

 of plague in the fourteenth century more than one 

 fourth of the population of Europe, about 25,000,000 

 people, died, ten thousand persons dying in one day 

 in Constantinople. In 1664-1665 London had an 

 epidemic of plague which carried off 68,500 persons 

 out of a population of 460,000. 



It is supposed that in all of these epidemics other 

 infections were present, probably malignant typhus 

 fever and "spotted fever," both of which are favored 

 by the same unsanitary conditions that are so great 

 a factor in epidemics of plague. 



Bubonic plague has never been epidemic in Amer- 

 ica, although a considerable number of cases have oc- 

 curred in San Francisco, brought by ships from China; 

 but by the enforcement of quarantine regulations 

 and medical inspection there has been no extended 

 dissemination of the disease. 



The death rates in different epidemics vary from 



