Water is a solvent as well as a carrier, and in this fact much danger lies. In its passage over or through the earth water may take up organic and inorganic matter that is detrimental to health, as when it comes in contact with sewage, which is liable to contain germs of disease. Often then this question of drinking-water is the hinge on which the whole subject of health turns. Whatever a family, or an institution, has become habituated to is taken for granted to be all right; but in the country, where sewers are unknown, the nearness of a cesspool or the stable yard is a constant menace to health. Indeed, in some soils, contiguity plays but a small part in the matter, for a well often drains a larger surface than is generally realized.

A deep well, properly situated, where the rainfall, carrying organic matter, must be filtered through earth and stone to reach its level, would seem to offer a water that one might drink with safety; but this is a subject that must be given more than passing attention. Who would willingly take the chances of a water-borne typhoid case, or the listless inertia of malarial poisoning, as the result of a summer's outing. City water taken from pure sources and filtered through sand-beds should be reasonably pure. When doubt as to its purity exists, boiling is the remedy, since almost all germs of disease that are likely to be found in water are killed by the application of heat at the boiling point. Filters for home use need the most exact and painstaking attention daily, or the water passing through them is made more impure. Water from the hot-water faucet, be it needless to add, is not suitable for drinking or cooking purposes.