BUBONIC PLAGUE 105 



nation of civilised people. When to a mixture of dust, old 

 rags, ashes, broken crockery, moist surface soil, etc., are added 

 fecal matter and the decomposing urine of animals and human 

 beings, a terribly insanitary condition of affairs prevails." 



The period of incubation in bubonic plague the 

 time which elapses between exposure to infection and 

 the development of the disease is usually from three 

 to six days. 



From the report of Dr. Lowson of cases treated in 

 the various hospitals of Hong Kong, under the con- 

 trol of English physicians, it appears that the mortal- 

 ity was much greater among natives of Hong Kong 

 than among the foreign residents of that city. The 

 mortality among Europeans (i i cases only) was 13.2$; 

 among Japanese (10 cases), 60 % ; among Portuguese 

 (18 cases), 66$; among Chinese (2619 cases), 93.4$. 

 To a considerable extent, no doubt, this difference in 

 mortality was due to the unfavourable surroundings 

 of the natives and their lack of proper nursing and 

 medical attendance, many of them being brought to 

 the hospital in a dying condition. 



Experiments upon rats and other animals show 

 that they become infected when cultures of the 

 plague-bacillus are deposited upon the mucous mem- 

 brane of the nose. 



During the epidemic prevalence of the disease 

 these animals die in large numbers, and there is good 



