ARTICLE XXI.

THE SHATTUCK LECTURE.

THE SOURCES, FAVORING CONDITIONS AND PROPHYLAXIS OF MALARIA IN TEMPERATE CLIMATES, WITH SPECIAL REFERENCE TO MASSACHUSETTS.

BY THEOBALD SMITH, M.D.

OF BOSTON.

DELIVERED JUNE 9, 1903.

THE SOURCES, FAVORING CONDITIONS AND

PROPHYLAXIS OF MALARIA

IN TEMPERATE CLIMATES, WITH SPECIAL · REFERENCE TO MASSACHUSETTS.

INTRODUCTORY.

AFTER I had accepted the honor of addressing you this evening as Shattuck lecturer, several topics of great interest to me presented themselves. After carefully considering them in the light of the provisions of the Shattuck bequest, it seemed to me that a discussion of Malaria, with special reference to our own State, would at this time be the most useful. I accepted this self-imposed task the more willingly as since 1895 I had been giving much time during the summer months, under the auspices of the State Board of Health, to the study of malaria and the local conditions favoring it. Most of the facts I have personally gathered we owe to this Board; for without their active coöperation the topography of the disease could not have been investigated.

If we were to depict the dissemination of malaria, this scourge of an invasive and militant civilization, upon the globe, we would paint it as a black belt girdling the tropical world and extending its lesser shadows in tongues toward the temperate zones. These shadows become less and less distinct the farther north we go. Though the harm it does to northern civilization is infinitesimal compared with its almost forbidding attitude in the tropics, yet even with us the energy needed for the ceaseless struggle for existence

suffers severely when malaria is invading the blood the integrity of which is so essential to our well-being.

Many things have conspired to bring about a renewed public interest in this disease. First and foremost the stimulus created by the colonial expansion of European nations, next the conditions which paved the way for a scientific demonstration of the existence of an intermediate host or carrier in the mosquito, and lastly the tendency of the intelligent classes in our climate toward suburban and rural homes and the general quickening of all interests in animal and plant life, have enlisted not only the attention of the public but their material support for the suppression of conditions favoring malaria. These various interests are perhaps a sufficient excuse for dealing with the newer aspects of this subject on this occasion. But the greater stimulus to me has been the fact that malaria is a prevalent disease of our State, that it has for us a decidedly sanitary as well as economic bearing. Some overworked and apathetic practitioners in rural communities may perhaps say, "What have the newer developments in regard to malaria to do with us? We can cure tertian fever with quinine and we can with equal readiness cure any relapse." This is true as far as it goes; but it would be a very narrow view to take and would, I feel sure, be spurned by our Society as unworthy of its past record and future promise. There is, however, a concealed, or at least overlooked, misinterpretation here which I cannot pass over in silence.

Medicine's legitimate field of work is not only sickness but health. Medical science has been moving the pivotal. point of successful combat with disease more and more toward the well man. Hence we have the two great departments of the medicine of to-day, the curative and the preventive. The latter, the latest to develop, is yearly growing in importance and will eventually overshadow the former; for it is based on sounder biological and economic principles.

Preventive medicine acts in an entirely different way from curative medicine. The latter saves its patient here and there and its services are conspicuous and positive, but the former works only collectively in a negative way and its services are inconspicuous. It also saves lives and prevents disease, but only through cold and dry statistics can it lay any claim to its achievements. It works by slow increments. Like the builder's screws which, placed under a building, raise it through an inappreciable distance each day, so preventive medicine slowly raises the sanitary level, and the total aggregate of all the inappreciable increments. means many lives saved and much illness prevented. The study of malaria and the application of the principles underlying it mean no new cures, but a steady elevation of the healthfulness of rural life, the only source of a robust generation.

My task was finally made still easier from the observation I have made frequently of late that among many physicians, engineers and educated people generally, the mosquito has as yet no assured position as a transmitter of the malaria parasite. If our recent developments are to have much value, they must be applied at once, the principles must be made operative and enter intimately into the life of rural populations. We have become now fully cognizant of the hurtfulness of sewage out of place and of sewer gas. In fact our legislative sensitiveness to sewer gas became so great that both capital and labor trusts are said to batten on the severe restrictions created by it. Of how much more definite significance in pathology than sewer gas is the malaria organism! But the history of sewer gas legislation shows what can be done if the public interest is once aroused. Fortunately, the prevention of malaria does not demand such artifical measures as are in use against sewer gas, but only such as will add permanently to the utility and beauty of the land.