ON THE INFLUENCE OF WEATHER UPON MORTALITY. 815 



mind that the change is gradual : thus, in May, with a temperature of 51°-9 there 

 is a mortahty of 193-5, which is still below 225-4, the mortality corresponding 

 with a mean temperature of only 49°- 1. But if this be a rule, then the months 

 of April and July are exceptional, the April with a lower mean temperature hav- 

 ing also a slightly higher death-rate, the anomaly perhaps depending upon other 

 meteorological elements. The April with the higher mean temperature and the 

 lower death-rate had a mean barometric reading of 29-751, and a rain-fall of 

 3-20 inches; the other April had a mean barometric reading of 30-177, and a rain- 

 fall of only 1-04 inches, — the one a low atmospheric pressure with a surplus 

 humidity, the other a high rate of atmospheric pressure with a deficit of moisture. 

 If I had selected the April of 1860, whose mean temperature is only 02° above the 

 one in the table, namely 41-5°, the rule would have been sustained, the death-rate 

 for that month being 290-2. The July with the lower temperature and lower death- 

 rate had a mean barometric reading below the average of the six years with a 

 rain-fall above it ; the July with the higher mean temperature and death-rate had 

 a barometric reading above the average of the six years with a rain-fall below the 

 average. The July of 1857, with a mean temperature only one degree below that 

 in the table, had a death-rate of 210-5. 



Monthly Range of Temperature. — The relation of monthly range of tempera- 

 ture to the death-rate from all causes is also shown in Table A, the means of the 

 four sections being as follows : — 



Se'="°'^- Mortality. J^TemJeJatoe. 



Maximum, 269-49 36 4 



Major, 233-25 37-2 



Minor 214-26 396 



Minimum, 185-85 33-9 



K we adopt the same plan as 

 six two excessive years, and ( 

 ing results : — 



with the mean temperature, constituting out of the 

 comparing them with the mean, we have the folio w- 





January. 



February. 



March. 



April. 



May. 



June. 



i Months of greatest Montlily Range, 

 ^ Months of least, „ „ 

 \ Means of the Six Years, . . . 



50° 1 

 21-7 

 34-1 



253-2 

 296-6 

 265-3 



56° 

 290 

 38-3 



250-1 

 246-9 

 257-4 



56°-0 



27-0 

 37-3 



257-8 

 283-2 

 249-8 



61-°0 

 32-2 

 41-9 



227-1 

 290-2 

 242-8 



54-7 

 31-2 

 41-6 



210-4 

 228-4 

 219-5 



66°5 

 27-3 

 39-5 



213-3 

 215-0 

 208-6 







July. 



August. 



September. 



October. 



November. 



December. 



, Months of greatest Monthly Range, 

 Months of least, „ ,, 



! Means of the Six Years, . . . 



1 



46°5 

 26-2 

 34-6 



210-5 

 192-3 

 204-5 



53°0 

 25-1 

 35-7 



224-1 

 173-1 

 189-4 



55°-0 



27-7 

 37-8 



194-6 

 165-0 

 187-7 



47-0 

 29-6 

 36-2 



208-0 

 210-4 

 198-2 



50°0 

 26-5 

 33-9 



231-3 

 230-0 

 237-1 



40-8 

 22-7 

 32-1 



1 

 257-7, 

 259-0 

 247-9 



VOL. XXIII. PART II. 





















4i 



I 





