It is wisdom also to have a reasonable space between a house and the highway, chiefly because the dust of the road is thereby kept from the house. There are people who find much enjoyment in watching passers-by on the road, and with them front windows would be as close to the road as possible, but it is wiser to have a front yard of at least fifty feet depth when possible. Finally, the location on a sidehill, even when otherwise advantageous, is to be regarded with suspicion if the subsoil strata are horizontal and neighbors up the slope have cesspools in use. The writer knows of several cesspools, built in rock, which, so far as their owners were concerned, have worked successfully for many years, but the water leeching away through the rock was finally discovered to be the cause of continual dampness in neighboring cellars, on lower ground, to the manifest discomfort of those occupying the houses. _Composition of soils._ Having thus discussed the location of the house with reference to its surroundings, let us now more carefully examine the character of the soil or earth foundation on which the house shall be built. All soil is made up of varying proportions of mineral and vegetable matter in the interstices of which there are usually to be found more or less air, water, and watery vapor. The mineral substances of soil include almost all of the known minerals, although many of them are found in exceedingly small quantities. The most common and the most important mineral elements of the soil of New York State are carbon, silicon, aluminum, and calcium, which combine in various ways to make either sand, sandstone, clay, shale, limestone, or other rock. The particular form which these mineral elements assume is of interest in choosing a location for a house, for two reasons:-- In the first place, it has been asserted that the mineral constituents of a soil directly affect the health of persons living on that material. For instance, the earlier writers on hygiene gravely pointed out that very hard granite rocks, when weathered and disintegrated, became permeated by a fungus and caused malaria. We are, however, now so sure of the cause of malaria that we only laugh at a theory upheld by scientists of only twenty years ago. Some constitutional diseases, including goiter and cancer, have been supposed to flourish in localities where an excess of calcium exists in the soil, and it is true that these diseases do have an unusual prevalence in certain limited districts; but no modern scientist ventures to say whether the boundaries of those districts are determined by the character of the soil constituents or by some other predisposing factor. The truth is that, in matters not absolutely determined by science, many theories usually have to be evolved and proved worthless before the real cause is found.