PART I.] Monthly Physical Phenomena at Benares and Allahabad. 271 



This station gets 28 inches less rain than Calcutta, and 20 less than the average of 

 the group of the endemic area stations ; bat it gets more than Dinapore, although the 

 latter is farther down the Granges. The months of lowest temperature are also the months 

 of minimum cholera ; and although the months of mean maximum temperature do not 

 coincide with the maximum cholera-months, there is yet a certain degree of coincidence 

 between the degree of temperature and cholera prevalence. The mere fact of a month 

 being warm, however, by no means implies a corresponding increase of cholera ; on the 

 contrary the tables show that, whereas 380 cases have occurred during 51 years in August, 

 only 77 occurred in September, although the mean temperature of the latter month is 

 only half a degree lower than the former. The temperature becomes 2" cooler in January 

 than at Dinapore, but on the other hand is a couple of degrees warmer at the maximum 

 in May. 



One of the months of maximum relative humidity (August) coincides with the 

 maximum cholera, but the month preceding this has the same mean hygrometric 

 condition with only half the cholera, and the month after it is nearly equally moist 

 and warm, but has only a fifth of the cholera : on the other hand, the driest month 

 of the year (April) furnishes the next highest number of cholera cases. 



With regard to the state of the barometer, it will be seen that the highest 

 pressure corresponds for the most part with months of minimum cholera, and it so 

 happens that the lowest pressure corresponds with the maximum — the reverse of the 

 general result of the Calcutta analysis, — where the minimum cholera (July and August) 

 and minimum average pressure almost coincided. 



(2) Allahabad. 



Following the course of the Ganges, the next important station of which we possess 

 fair data is the City of Allahabad, situated at the angle formed by the junction of 

 the Jumna and the Granges. We have now followed the latter from Calcutta, a distance 

 of some 600 miles, and observed the gradual transition of the maximum of cholera- 

 prevalence at the several stations of its plains from March and April to July and 

 August. 



This station, however, still manifests, to a considerable extent, the tendency to 

 suffer from cholera during the spring season, as nearly 36 per cent, of its total cholera 

 has occurred during the first five months of the year, January to May, the three months 

 March to May furnishing nearly the whole of them. 



On the other hand, the last three months of the year, October to December, 

 furnish very few, only 2 per cent, of the total, or about 14 per cent, less than the 

 proportion furnished by the group of stations in the endemic area; while during 

 the rainy season nearly 33 per cent, more occur, so that the contrast is very consider- 

 able. 



