In attempting to develop a system of rural hygiene, by means of which the full value of the advantages of pure air and sunlight, of healthful exercise and sound sleep, may be realized, the first step should be a proper location of the house. For, while it is possible to have good health in houses not advantageously located, and while the influence of unsanitary surroundings is not as great as was formerly supposed, yet there can be no question but that some influences, whether they be great or small, must result directly from the situation of a dwelling. For example, it has been noticed that a house whose cellar was damp was an unhealthy house to live in, and early text-books on hygiene quote statistics at length to prove this fact. The early theories connecting ill-health with conditions in and around the house have been handed down, and to-day some are accepted as true, although by the modern science of bacteriology most of the early notions have been upset. For example, it was considered dangerous to breathe night air in the vicinity of swamps, and in one of the Rollo Books, so much read by the children of the last generation, Uncle George requires Rollo, on a night journey through the Italian marshes, to stay inside the coach with the windows closed in order not to breathe the night air and so contract malarial fever. We know to-day that malarial fever comes only from mosquitoes, that night air has nothing to do with disease, and we hear the general advice of doctors that, except where it means the admission of mosquitoes, we should always sleep with our windows open in order to breathe as much night air as possible, because the night air is purer than any other air. These early traditions have not only concerned themselves with damp cellars and night air, but they have insisted that even the vicinity of a swamp or pond might lead to disease, and the State Department of Health of New York is in constant receipt of complaints because of alleged danger to health on account of some pond or swamp in the vicinity of houses. Again, one tradition says that a house should not be located in the midst of a dense growth of trees, because the shade of the trees, however welcome in summer, will generate and maintain a condition of dampness in the house and, therefore, be injurious to the health of the inmates. Another tradition is that a house ought not to be located in a valley, but that a hilltop, or at least a sidehill elevation, is preferable, the possible dampness of the valley being alleged again as the reason.