THE WEATHER, INFLUENZA, AND DISEASE. 



589 



height in the middle of March. The actual duration of the attack was only seven weeks, 

 viz., from 11th February to 31st March. The Post Office figures coincide in every 

 particular. 



Of the six epidemics, three occurred in winter, two in spring, and one in early 

 summer. If the total number of weeks be added together in which influenza was 

 epidemic during the last six years, we arrive at the large figure of sixty-eight, — that is, 

 one in every four and a half. 



The spring epidemics were, as a rule, of shorter duration than those occurring in 

 the winter, the one summer attack holding a mediate position. 



For the sake of clearness, the subjects of the weather on influenza, and of the 

 influence of influenza on disease, are taken up seriatim in the sequel, first in connection 

 with each epidemic, secondly with regard to the epidemics treated together. 



Number of Cases involved. 



Before considering the relations between the epidemics and the weather, it would 

 perhaps be as well to give the number of patients attacked during the course of each 

 epidemic, both in the Infirmary and in the Post Office. As the total number of the 

 possible patients in the Post Office is close upon 1000 (probably a little above that 

 figure), the percentage attack can be calculated. 



Number of Cases. 



Year. 



Infirmary. 



Post Office. 



Percentage in Post Office. 



1889-90, .... 



1891, 



1891-92, .... 



1893, 



1893-94, .... 

 1895, 



Total, 



Per year, 



26 

 28 

 189 

 19 

 59 

 44 



95 



35 

 139 



15 

 116 



74 



9-5 



3-5 

 139 



1-5 

 11-6 



7-4 



365 



474 



47-4 



60-8 



79-0 



79 



The three winter epidemics have therefore been the most severe, judging by the 

 number of cases of pure influenza which were recorded during their course. 



The Weather and Influenza. 



1. The first epidemic, which began on the 15th of December 1889, and continued 

 for nine weeks, was preceded by six weeks of cyclonic weather, which was not, however, 

 accompanied by a heavy rainfall. The temperature had been a little above the mean 



