THE RAT THEORY OF PLAGUE EPIDEMICS 



13 



In all the districts in Hong-Kong in the year 1902, with three 

 exceptions (European quarter), the charts showed that the epizootic fades 

 first, and is followed by the epidemic. Immediately the rat plague 

 diminishes or disappears, human plague becomes more or less extinct. 

 The accompanying Charts II., III., showing the condition of the 

 outbreaks in the Health Districts, Nos. 9 and 10, clearly prove, to my 

 mind, the close relationship which must exist between epizootic rat 



HONGKONO DISTRICT No. 0.-1002. 



tiioSSuu 



H>^&j.i.< 



m 



xra_n_ 



7 U 21 M 1 1 1 IS 3,', 4 1 1 IS JS I .S li 2-i 2U G 13 20 27 3 10 17 U I 8 15 22 29 5 12 li) 2G 2 9 IC 23 30 7 14 21 28 4 1 1 18 2i 2 9 IG 23 30 



Chart II. 



rir)NGKONG DISTIilCT No. lO.-lOOS 



n_rL_ 



1 2S 4 I1IS2.-, I I1I.S2.-) 1 S 15 22 2',! G 1320 27 3 10 17 24 1 8 l.i 22 20 J I2102G 2 9 ir,;3.iO 7 11212S 4 111835 2 9 1623 30 



Chart III. 



plague and epidemic plague. These charts demonstrate the fall in the 

 epizootic, followed by a similar defervescence in the amount of epidemic 

 plague. 



(b) During the year IQOJ. 



An important point in connection with the determination of the 

 relation of the epidemic to the epizootic, is that, during this year, one is 

 enabled to follow closely the train of events from the commencement of 

 the year. 



(227) Q I 



