PASTEUR AND AFTER PASTEUR 



and C, those known not to be infected. By setting 

 " guinea-pig traps " in these three classes of rooms, 

 it was found that class A furnished nearly three 

 times as many fleas as class B, and twelve times 

 as many as class C. 



8. Monkeys, put under similar conditions of 

 experiment, were found just as liable as guinea- 

 pigs to infection. 



9. A chart, showing the number of plague- 

 infected rats found among the hundreds daily killed 

 in Bombay during an outbreak of plague, and the 

 number of human plague deaths during the same 

 period, showed, very clearly, that the infection goes 

 from rats to man. 



Thus, by experiments, observations, and sanitary 

 methods, all working together, year in year out, 

 the transmission of bubonic plague, by rat-fleas, 

 from rats to man, was discovered and proved. 

 " These discoveries," says Bannerman, " provide 

 us, for the first time, with a sure and scientific 

 basis on which to work, and have explained the 

 cause of failure of the well-meaning efforts to 

 combat the disease which were made when plague 

 first appeared. Efforts are now concentrated on 

 the breaking of the chain of events leading from 

 the rat through the flea to man." 



Then he goes on to estimate what hope of 

 success attends these efforts. What can be done ? 



