640 



Mr. Alexander Buchan 



[March 25, 



identical with that for teething (Fig. 23), and it may be added that the 

 curve for hydrocephalus is simply a reproduction of the same curves. 

 Now these curves show a small, but distinct, and, as revealed by each 

 year's figures, a constantly recurring secondary maximum in summer, 

 which in the case of London is almost wholly due to the bowel 

 complications of these diseases. The curve (Fig. 24) for convulsions 

 for New York, where the summer temperature is 10° -0 hotter than in 

 London, shows this feature of the curve enormously magnified, so 

 much so, indeed, that instead of being, as in London, an insignificant 

 secondary maximum, it stands out as the prominent feature of the 



Fig. 23. 



Jan. Feb. March. April. May. June. July. Aug. Sept. Oct. Nov. Dec. 



Mean 



I I I I 



^> 



I I 1 



Ml) 



I I 1 



I I I 



II I Cl 



^=n;::^7 



50 Ll i I III 1 I I I III III MM III 111 I I II Ml 111 M 1 U 



Teething. 



50 



Mean 

 30 



"I I I 



1 1 1 



111 



nil 



Hi 



1 1 



1 ! 1 



Fig. 24. 

 I II I 



I ( I 



I I i I 



t I I 



i I I 



Convulsions (New York). 

 Fig, 25. 



INI |>rs 



(III 



I I I I 



III 



I I 



All Nervous Diseases (New York). 



II ! 



1 I 1 1 J 



curve. Whilst this result is doubtless largely due to complications 

 with bowel complaints, it is, as an examination of the statistics shows, 

 in no small degree caused by the direct influence of the great summer 

 heat of New York on the nervous centres. This is impressively shown 

 by the mortality curve for the whole of the nervous diseases (Fig. 

 25), which is even more pronounced in this particular than the curve 

 for convulsions alone (Fig. 24). Keeping this fact in view, the 

 peaks showing an increased fatality in London from cephalitis 

 (Fig. 18) and suicides (Fig. 19) during July and August acquire, in 

 the eyes of the physician, a more impressive significance. 



