642 



Mr. Alexander Buchan 



[March 25, 



disease, and kidney disease exhibit most striking, and in many cases 

 the closest alliances with each other. Lastly, while bowel complaints 

 attain their greatest mortality when temperature is highest, diseases 

 of the respiratory organs when it is lowest, nervous diseases during 

 the dry weather of spring and early summer, and skin diseases and 

 certain fevers during the raw weather of autumn and early winter, 

 such diseases as ileus, that are quite removed from weather influences, 

 exhibit curves which show no obedience whatever to season, but only 

 a succession of sharp, irregular serratures resembling the teeth of a 

 saw. 



Atrophy and debility are most fatal to the very young in summer, 



Fig. 29. 



The Great Plague of London. 



but to the aged in winter ; in the former case the complication being 

 with bowel complaints, and in the latter with diseases of the respira- 

 tory organs. The annals of influenza show that a special character 

 is given to this epidemic according to the season of the year in which 

 it occurs. Thus when it occurs in spring the head and nervous 

 system are most afiected, but the bowels when the epidemic prevails in 

 summer and autumn. 



Fig. 29 shows by the doubly-dotted line, or highest curve, the 

 weekly mortality of London during the Great Plague of 1665, the lower 

 dotted curve the mean weekly mortality of the last six plagues, and 

 the solid curve the mean weekly mortality from all other diseases 



