237 



NATURAL DEATH, PUBLIC HEALTH 



laissez-faire policy would be better, or that public health 

 efforts have not been enormously valuable in connection 

 with typhoid fever aad diphtheria. My purpose is quite 

 other, being solely a desire to emphasize two things, viz: 

 1. That the trend of human mortality in time is an 



no 

 so 



80 

 70 



DIPHTHLPIA 



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LJ 



'^^ 99130001 Oi 03 04 05 06 07 OS 09 10 1/ le 



YEAH 



Fio. 56. — Like figure 55^ but for diphtheria and croup. 



extraordinarily complex biological phenomenon, in 

 which many factors besides the best efforts of health 

 officials are involved. 



2. That for many causes of death a vast lot needs to 

 be added to our kaowledge of etiology, in the broadest 

 sense, before really efficient control can be hoped for. 

 This knowledge can come only through scientific investi- 



