This branch of the subject is closed with the remark that it would be well if physicians, and especially the younger ones, gave more attention to the preservation of their own health than many of them do. The possession of a medical diploma does not prevent the evil effects of irregular and hurried meals, insufficient sleep, exposure to inclement weather, and lack of systematic and sufficient exercise; and too much tobacco, sometimes too much alcohol, and in exceptional cases too much study and literary work, so often combine with anxiety about individual patients or with pecuniary worries to damage the digestion and nervous system of the young practitioner that the wonder is that so many survive the ordeal. And, in fact, the mortality among physicians under the age of thirty is higher than that of any other profession during the same period of life. III. Public Hygiene in its Relations to Physicians. An important difference between man and animals is found in the extent to which he will sacrifice a present pleasure or convenience to secure a future good or to avoid a future evil. The savage will do this to only a very limited extent--little more, in fact, than the beaver or the squirrel--and the lesson is learned but slowly and by sad experience. This is especially the case as regards matters affecting health. When a man begins to take special precautions as to his diet or exercise, having in view rather his future health than his present comfort and tastes, he has in most cases already begun to suffer from the effects of his imprudence, and does not commence a hygienic course of life as a perfectly sound and healthy person. The same is true for a community. It will not usually submit to the burden of taxation necessary to secure drains and sewers or a proper registration of vital statistics, nor to the cost and inconvenience of the machinery necessary to limit the spread of contagious diseases, until the neglect of these things has resulted in such an amount of disease and death as to forcibly call attention to the matter. The result is, that the burden is far heavier than it would have been had the work been undertaken in proper season, and individuals may find it to their interest to leave the place and settle elsewhere rather than remain and meet their proportion of the expense.