habits of men will be changed and certain diseases which arise from alimentary vices will disappear. Already, because the excesses of meat eating to which our fathers gave themselves up are exceptional to-day, gout has become very rare; it is doomed to disappear. Obesity, sick headache, and some diabetes connected with overeating will be suppressed when men resign themselves to moderation. They had practically disappeared in Germany under the influence of the forced alimentary restriction during the war. Alcoholism, also, with its hepatic, nervous, and mental symptoms, should vanish if the nations had the firm will to abolish it. There would remain only a certain number of hopeless drunkards-just as there are some morphine addicts throughout the world. As regards the infectious diseases, of which the germ is introduced through the digestive tube-typhoid fever, cholera, and dysenteryand as regards enteritis, brought on by intestinal parasites, they are already less frequent than formerly, and they are destined to disappear through the progress of nutritional hygiene and especially through the use of sterilized drinking water. Tuberculosis itself, in so far as it is related to the diet in infancy, should diminish. Such is the importance of the results which we may expect from nutritional education. If it is given early and very generally, if it is addressed to the children and to their mothers, it will efface little by little from pathology a series of diseases which result from dietary errors, and it will improve the health of individuals, and the beauty of the race. It will accomplish the double purpose, both individual and social, which the philosopher Guyau assigned to a good education. It is, therefore, with good reason that we make it one of our first considerations. A FIFTY-YEAR SKETCH-HISTORY OF MEDICAL ENTO MOLOGY.1 By L. O. HOWARD, M. D., Ph. D. [With 10 plates.] A real history of medical entomology would require a year or more in its preparation and should be done, perhaps, by two men, the one a medical man (a pathologist), and the other an entomologist, since a complete history, written by one or the other, would unconsciously emphasize the importance of one side. But the time has come for the preparation of a consecutive account of the main features of the extraordinary development that has taken place in the past few decades; and this article, however faulty and however hastily done, is an attempt to do this. In any history there is always a balancing of the advantages and the disadvantages of a too near or a too distant view of events, and if the present view is too near it may at least contain suggestions for the consideration of the future historian. In 1871 the idea that any specific disease might be insect borne was not mentioned in any of the standard medical treatises. In this direction the world was as ignorant as it was 300 years earlier, when Mercurialis suggested the idea of food contamination by flies coming from the excretions of those dying from the "black death" to visit exposed food supplies. Even this perfectly obvious conclusion of the old Italian physician made little impression, and, although occasionally repeated from time to time through the years by one observer or another, mainly in reference to Asiatic cholera, flies generally, were regarded as harmless nuisances, and, perhaps, even as beneficial as destroyers of offal in their maggot stage. We can hardly blame the workers in medical sciences before the days of microbiology for indifference or for lack of vision in this direction, in spite of the fact that here and there in different parts of the world there existed among the people popular beliefs which connected certain insects with disease. It was so in India, in Africa, 1 Reprinted, with slight alterations, by permission of the American Public Health Association from "A half century of Public Health-Jubilee historical volume of the A. P. H. Assoc.," N. Y., 1921 (pp. 412-438). 101257-22- -37 565 in South America, and even on the Roman Campagna, a home of malaria, the poor peasants long ago connected the idea of mosquitoes with the idea of fevers. But there were a few men before Pasteur's discovery of pathogenic bacteria, and long before anyone had dreamed of disease-carrying protozoa with alternate hosts, who had imagined in a way the connection between mosquitoes and yellow fever. Louis D. Beauperthuy, a French physician long resident in the West Indies, as early as 1853 elaborately argued that yellow fever is conveyed to man by mosquitoes, but he supposed that the insects carried the virus from decomposing matter which they had visited. Even earlier, in 1848, Dr. Josiah Nott, of Mobile, had contended in a published article that the specific cause of yellow fever exists in some form of insect life. The first decade of our 50 years was almost passed when the first great discovery in medical entomology was made, a discovery which, although it had no connection with bacteria or protozoa, led directly to others, and in fact opened the way to the vast field of discovery in which many men of many countries have worked and are now working. This was the discovery by Dr. Patrick Manson of the full life round of certain filarial worms, in which certain mosquitoes play a vital part. So revolutionary was this work and so unimagi nable in its results even to intelligent practitioners that the late medical inspector, J. S. Ames, of the United States Navy, has told me how the Navy surgeons of different nations, coming together by chance on the China station, "used to chaff crazy Pat Manson about his mosquito filaria ideas." Manson's discovery was brilliant and revolutionary. It was the result of long work under trying condi tions and in the face of a discouraging lack of interest and even serious doubts as to his perfect saneness on the part of his colleagues, and he deserves even greater honor than was given to him, although he has been hailed as a pioneer and a great leader by the medical profession and the scientific world at large. His work led directly to the great achievement of Ross in regard to malaria. But before we take up Ross's wonderful work we must for an instant refer to an extraordinary paper by A. F. A. King, a Washington physician with a speculative mind, who published in 1883 an extended argument to prove that malaria is carried by mosquitoes. As a closely reasoned argument this paper was as nearly conclusive as would be possible without actual experimental evidence. But the time was not ripe for the acceptance of this idea, and laboratory technique and microbiological science were not far enough advanced to allow even promising confirmatory experimentation. I am inclined to pity myself when I remember my incredulous frame of mind when Doctor King broached his theory to the late C. V. Riley and myself |