APPENDIX III 



Influence of Seasons on Suicide.^ 



The average number of annual suicides for the three countries imder 

 consideration, taken together, is 996'3. The average number of suicides 

 occurring in June (for all three countries together) is 105' 6. The average 

 number occurring in May is 104, and the average number occurring in 

 December is but 61. 



There is, in all three countries, a steady progression from January till 

 June, and an equally steady falling off from July to December. It may 

 be said that these variations in the suicide-rate are due to the variations 

 in the temperature, and that the latter are the cause of the former. And, 

 indeed, some writers, notably Professor Perri, have endeavoured to trace 

 a connection between thermal variations and variations in the rate of 

 homicide and suicide- With variations in the rate of homicide we are 

 not here concerned, but we may say that homicide is not by any means 

 a phenomenon similar to suicide. Neither the causes which produce 

 homicidal tendencies, nor the homicidal tendency itself, can be assimilated 

 to the tendency to commit suicide. The homicidal tendency is far more 

 intimately bound up with heredity and with other causes of a biological 

 nature, and thermal variations, acting on the peculiar physiological and 

 psychological constitution of the criminal, do undoubtedly bring about an 

 increased tendency to commit homicidal acts under the influence of heat. 

 The tendency to commit suicide, however, is not thus directly connected 

 with thermal variations, as will be seen in the next chapter. A good 

 proof of the fact that an increase of heat does not produce an increase of 

 suicide hy itself and without co-operation of other factors is furnished by the 

 above figures. The average June temperature in Italy is 21° C. That of 

 July is 24'^ C, and yet the average number of suicides in July is less than 

 the average number in Jime. Similarly, although the mean temperature 

 of Italy is considerably higher than that of Prussia or Prance, the average 

 number of suicides is about the same. The rise in the suicide-rate pro- 

 ceeds pari passu with the growth of economic activity, which is naturally 

 greatest when the days are longest (see pp. 279-287). 



', E. Durkheim, Le Suicide, p. 93. 



