222 THE POPULAR SCIENCE MONTHLY 



ment of tuberculosis, by municipal experience with the efficacy of water 

 filtration against typhoid fever, the " cleaning up " in a hygienic sense 

 of Havana during the American occupation, the wonderfully healthy 

 state of the Canal Zone under Gorgas as compared with that in the 

 time of the French control, the influence of a better understanding of 

 the effect of hook-worm disease on social conditions in the south, and 

 the importance of the destruction of the mosquito in the prevention of 

 yellow fever and malaria. The public looks first, and naturally so, to 

 its state and municipal laboratories for assistance, but it looks also to 

 the laboratories and hospitals of the universities for that wise guidance 

 and direction which, untrammeled by political expediency, is the result 

 of impersonal scientific observation and experiment. 



The problems which may be attacked by the university are both 

 general and local ; in many instances a most promising field of investi- 

 gation lies at the university's door. As is pointed out in Abraham 

 Flexner's Carnegie Report on Medical Education, the port of New 

 Orleans offers to Tulane a great opportunity for the study of tropical 

 diseases, and the industries of Pittsburgh offer to its university un- 

 usual material for the study of occupational diseases. The port of San 

 Francisco, draining as it does the Orient, and soon to feel the influence 

 of the Panama canal, offers to the university which will grasp it a field 

 for the study of tropical and unusual imported diseases not open to any 

 other city in the temperate zone. Industrial centers other than Pitts- 

 burgh offer advantages for the study of occupational diseases and the 

 influence of industrial conditions. New York, Chicago and other large 

 cities with compact populations present their own problems and even in 

 sparsely settled rural districts arise questions of great importance. 



So also every community has the problems connected with the dis- 

 eases of infancy and of advancing years. The influence of bacteriology 

 in focusing the attention of investigators and of the general public on 

 the acute infectious diseases, though an influence of the greatest im- 

 portance to medicine and one responsible for much of the endowment 

 of research in this country, has had a tendency, on the other hand, to re- 

 tard the study of diseases not due to bacteria or protozoa. The pendu- 

 lum now, however, is swinging the other way, and the time has come to 

 attack, with the aid of the methods of chemistry and physiology, the 

 chronic diseases, the disturbances of metabolism and of internal secre- 

 tion and the affections peculiar to infancy and old age. Only recently 

 have the diseases of advanced life attracted an attention commensurate 

 with their incidence and importance. As the fruits of the investiga- 

 tion of the acute infectious diseases have increased the expectancy of 

 life by diminishing the mortality of infancy, childhood and early man- 

 hood, so the study of the chronic diseases incident to middle life and 

 advancing years, should, by the determination of predisposing causes 

 and methods of prevention, lead not only to a still greater stability of 



