ON THE INFLUENCE OF WEATHER UPON MORTALITY. 



313 



1857, but not to so great an extent as is witnessed in the case of the aberrant 

 August ; and forasmuch as the cause in both instances is obviously identical, it 

 will be sufficient to explain it in reference to August only. 



Tear. 



1857, 

 1868, 

 1860, 

 1859, 

 1861, 

 1862, 



Mcajor 



Minor 



Minimum 



Mortality. 



Mortality. 



Mortality. 



224-1 





199-5 

 192-4 

 178-7 

 173-1 

 168-4 



Mean 189-4 



August 1857. — Registrar-General : " The mean temperature in August realised 

 the very unusual height of 60°, and as July also, and the beginning of September, 

 had mean temperatures higher than usual, bowel complaints (diarrhoea, dysen- 

 tery, and cholera) became so prevalent and fatal, that instead of only 56 dying 

 from these complaints in every hundred thousand persons, as in 1856, no fewer 

 than 112 deaths occurred in a like population in 1857." 



We proceed now to consider the influence of the several meteorological 

 phenomena upon the mortality from all causes more in detail, and first we have 

 to consider 



The Influence of Temperature upon Deaths from all Causes. 



Turning to Table A, we find that although the column of mean temperature 

 does not increase in value so evenly as the column of mortality diminishes in 

 value from above downwards, nevertheless over the whole of the two columns 

 there is a distinctly inverse relationship ; and if we compare the means of the 

 four sections previously described, we find that the relationship existing between 

 temperature and deaths from all causes is as follows : — 



Mean of 



Maximum Section, 

 Major Section, . 

 Minor Section, . 

 Minimum Section, 





Mean 





Temperature 



269-49 



38-3 



233-25 



43-1 



214-26 



49-5 



185-85 



54-3 



Mean of the 72 Months, 225-71 



46-3 



To ascertain the difference of influence between a high and low mean tempera- 

 ture, I have constituted, out of the six, three factitious years; for the one, taking all 

 the lowest temperatures of the six corresponding months ; for another, the highest 

 temperatures ; and for the third, the mean of the six corresponding months. The 

 death-rate of the three may be compared month by month. [Obviously, one dis- 

 advantage of such an arrangement is, that by associating the sequent months of 

 different years we at once dissolve the continuity of effect which the weather exer- 

 cises over mortality. It is important, in estimating the value of weather as an etio- 



