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 investigation 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 unusual 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 Pittsburgh 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 diseases 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 importance to medicine and one responsible for much of the endowment of research in this country, has had a tendency, on the other hand, to retard the study of diseases not due to bacteria or protozoa. The pendulum 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 secretion 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 investigation of the acute infectious diseases have increased the expectancy of life by diminishing the mortality of infancy, childhood and early manhood, 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