THE CAUSES OF DEATH 137 



atory organs, on the broadest basis, to include all such 

 matters as ventilation of buildings, etc., and the putting 

 of such a personal hygiene into general use through 

 education, would pay about as large dividends as could 

 be hoped for from any investment in public health secu- 

 rities. I am aware that much has already been done in 

 this direction, but in order to reap any such dividends 

 as I am thinking of, a vast amount must be added to our 

 present knowledge of the physiology, pathology, epidemi- 

 ology, and every other aspect of the functions and struc- 

 tures of respiration. 



