268 



L holer a in Relation to Certain Physical Phenomena. [part i. 



TABLE LIV. 



A SuTTimary of a portion of Tables XLV. and LIII. giving the percentages of the 

 aggregate seasonal Cholera in the selected group of Stations of the Endemic 

 and Non-endemic areas. 



Although the impression conveyed by a scrutiny of these tables regarding the 

 seasonal prevalence of cholera in the non-endemic area is clear enough taking the 

 stations as a group, it will nevertheless be observed that there are some half-dozen 

 out of the 25 stations where cholera appears to be more equally distributed over the 

 several seasons, approximating more closely to what is observed in Lower Bengal, as, for 

 example, instead of furnishing a proportion of " spring " cholera of about the average, 

 viz., 16*8 per cent., they furnish from 20 to 40 — a proportion which, though considerably 

 less than that of the Lower Bengal stations, approximates sufficiently near to command 

 attention. It will, however, be more convenient to consider this question when the 

 cholera-history and physical phenomena of individual stations come under review. 



It will be more convenient also to defer the study of the relation which the average 

 monthly and seasonal rainfall may hold to cholera-prevalence. It will be sufficient to 

 observe here that the proportion of rain which falls over the two great areas into which 

 epidemiologists have divided the province of Bengal, not only differs as to amount, 

 but also as to its proportionate distribution over the annual period. For example, if 

 the mean of the rainfall of the wet season — June to September — at the several stations 

 which form our Lower Bengal group, be calculated, it will be found that it is equal to 

 about 75 per cent, of the total fall for the year; but the mean of the rainfall of the 

 selected group of stations in the non-endemic area for the same period exceeds this by 

 10 per cent. ; hence during the winter and " spring " seasons, the rainfall of the non- 

 endemic area is not only less because the total annual fall is less, but also because 

 proportionately so much more of it falls during the wet season. There are, as might 

 have been anticipated, some deviations from these results in individual stations in. 



