_Soil._--He insists, first of all, on the great importance of the soil being _dry_--either dry before artificial means are used to make it so, or dry from drainage. To this end some elevation above the surrounding land conduces. A hollow below the general level should, as a matter of course, be avoided; for to this hollow the water from all the adjacent higher land will drain, and if the soil be impervious the water will lodge there. It will thus be damp, and, as is well known, it will be a colder situation than neighbouring ones which are a little raised above the general level. Those who live where they can have gardens will find the advantage of the higher situation in its being much less subject to spring and early autumn frosts than the hollow just below. This is due not only to the former being damper, but to the fact that the heat of the ground on still nights passes off into space (is “radiated”) more rapidly than from the higher situation, where there is more movement in the air. The soil should not be retentive of moisture, as clay is when undrained; nor should it be damp and moist from the ground water (concerning which a few words will be said farther on), as is much alluvial soil, i.e. soil which has been at some former time carried down and deposited by rivers or floods. On the whole, sand or gravel, if the site be sufficiently elevated, is probably the best, as it allows all water to get away rapidly. Then come various rocks, as granite, limestone, sandstone, and chalk.