ON THE INFLUENCE OF WEATHER UPON MORTALITY. 



337 



of the winds exerts any influence upon the death-rate from zymotic diseases. 

 The following table is constructed like the former, the figures representing the 

 force of the winds in pounds weight : — 





Jan. 



Feb. 



March. 



April. 



May. 



June. 



Average, 



Pressure of the winds during the months ) 

 with the greatest death-rate, . . J 



Pressure of the winds during the months ) 

 with the least death-rate, ... J 



2-95 

 2-36 



1-77 

 1-80 



1-88 

 1-89 



1-18 

 1-45 



1-79 

 1-34 



1-36 

 1-67 



1-64 

 1-68 





July. 



August. 



Sept. 



Oct. 



Nov. 



Dec. 



Pressure of the winds during the months ) 

 with the greatest death-rate, . . j 



Pressure of the winds during the months \ 

 with the least death-rate, . . . j 



Ill 

 1-44 



1-04 

 0-82 



1-38 

 1-38 



2-34 

 1-28 



1-09 

 2-36 



1-80 

 2-32 



The average force of the winds over the six years is 1 -59, and therefore in both 

 of the extreme years of the above table the averages are rather high. It might 

 have been supposed, that when the death-rate from zymotic diseases was higher, 

 the relative pressure of the wind would have been low, indicating calm rather 

 than hreezy weather ; but if the above table proves anything, it is the very oppo- 

 site of that. 



That the weather has to do with fluctuations in the death-rate from zymotic 

 diseases no one will doubt, but the manner of its operation it is difficult to explain. 

 In countries where marshes form an ample source of some of these diseases, the 

 effects of temperature and humidity are obvious enough ; but in this country, in 

 which the germs of such diseases spring from unrecognised sources, the influence 

 of the weather in bringing them hither, developing, and propagating them, is 

 not so plain. I make no comments upon the foregoing facts ; it was not to be 

 expected that any very striking results would be deducible from a mere compari- 

 son of the meteorological data with the death-rate from a class of diseases com- 

 prehending so great a variety. In the tables I have given the death-rates from 

 three diseases of the zymotic class — viz., Typhus, Scarlatina, and Diarrhoea— 

 and it would have been interesting to have shown the effects of meteorological 

 phenomena upon each of these, but that must be left to another opportunity. 



B. The Influence of Weather upon Mortality from Phthisis Pulmonalis. 



Instead of examining the influence of weather upon the tubercular class of 

 diseases as a whole, it will perhaps be more profitable to confine my remarks to 

 one, and that the most fatal, of such diseases. 



The order of the months according to the death-rate from phthisis, from the 

 highest to the lowest, following the means of the six corresponding months as in 

 Table C, is as follows : — 



VOL. XXIII. PART II. 4 Z 



