WOMAN'S HOME at the foot of a slope and in deep valleys, pointing out that they receive the surface drainage from the higher ground, and pre- dispose their occupants to epidemic diseases. High positions exposed to strong winds may be unhealthy if situated to leeward of marshy ground or the contaminated air of a manufacturing town. Two other points are worthy of con- sideration — viz., rainfall and mortahty. Rainfall within the British Isles varies from 25 inches per annum in the Eastern counties to 80 inches in the West of Scotland, and though this great variation does not appear to affect the health returns, it certainly has a very real effect upon the comfort of the individual. The death-rate is an infallible indication of the healthiness of a district, even when we eliminate the high mortahty due to local conditions of employment. SOIL The warmest and driest sites are on sandy and gravelly soil, the coldest and wettest on clay. Chalk is cold but not necessarily damp. Soil has to be considered not only in reference to climatic conditions, but also in relation to water supply, the character of which in most cases it determines. In new neighbourhoods the house may be found to stand on " made ground," the worst of all soils, and invariably unhealthy. The surface soil is not always closely related to the subsoil, and as the latter is often the more important factor in deter- mining the healthiness of the site, it is well to ascertain its nature before deciding to live upon it. Gravel overlying clay, if of no great depth, would imply a wet and cold site, as the surface soil would always be water- logged. WATER The healthiness of the household is largely affected by the character of the water supply, which must be considered both as regards its degree of hardness and its purity. Hardness results from the presence of lime and magnesia dissolved in the water. " Temporary hardness," which is removed by boihng, is due to carbonates, " permanent hardness " to sulphates of hme and magnesia. Hard water is readily detected by its behaviour with soap. Every householder knows how with certain waters the soap precipitates in flaky particles before it is possible to produce a lather. This means that part of the soap is used up in softening the water, or, in other words, that there is a daily waste of soap. Hard water causes the hmy deposit in kettles and boilers, and in time chokes up the hot-water pipes, involving danger of explosion if means are not taken for clearing them from time to time. It is also unpleasant for domestic use, causing roughness of the skin and " chap- ping " in winter, and is a fruitful cause of many bodily derangements, including dyspepsia, glandular swellings, gout, and rheumatism. Every grain of lime per gallon of water constitutes one degree of hardness, and it has been laid down by authorities that no public water supply should exceed 10 degrees. When this is exceeded it is worth while to instal a softening apparatus in connection with the domestic system. An efficient water softener may be purchased at from /lo to. £2.^ and upwards, according to the size of the household. It consists of a separate cistern in which a certain definite amount of " anticalcaire," or other softening agent, is introduced automatically into the water SURFACE WELL How surface wells are polluted. If a tube well, shown by dotted lines, is driven down below the clay, the water is safe from contamination as it leaves the main, and a filter system for intercepting the limy deposit which results. Well water may be similarly treated if forced into a cistern before use. Even more important than hardness is purity. This may be affected by the presence of an undue amount of mineral or other matter in suspension, generally visible to the eye, and the remedy is efficient filtration. On the other hand, the water may be contaminated by the presence of organic matter and disease germs. If this is suspected, it is best to have the water examined by an expert, whose fee would not exceed three guineas. Generally, it may be said that water from surface wells should always be viewed with suspicion. Deep well water is safe if not contaminated in the cistern. Public company supply water is mostly free from organic matter in dangerous excess, although some notable cases of pollution have occurred and not been detected until they have caused severe epidemics. To be contimied in Part 2 of Every Woman's Encyclopedia,
