Boiling. Where the water that you are obliged to drink is not known to be pure, then it can be made quite safe for drinking purposes by the simple process of boiling it for about ten or fifteen minutes. But this, except in travelling or in emergencies, is a lazy, slipshod substitute for pure water, and extremely unsatisfactory as well; for the boiling drives off all its air and other gases, and throws down most of the salts, so that boiled water has a flat, insipid taste. These salts, although sometimes regarded as impurities, are not such in any true sense; for the lime and soda especially are of considerable value in the body, so that boiled or sterilized water is neither a pleasant nor a wholesome permanent drink. Instead of boiling the water, get to work to protect your own well from filth of all sorts, if you drink well water; or, if not, to help the Board of Health to agitate, and keep on agitating, until something is done to compel your selectmen or City Council to secure a pure supply. [Illustration: THE DOMESTIC FILTER IN USE Unless the sand and charcoal in the glass bulb is very frequently cleaned, it serves merely as a "catch-all" for impurities, through which the water must flow.] Domestic Filters. Much the same must be said of _private_ or _domestic filters_. These are, at best, temporary substitutes, and should not be depended upon for permanent use. Many of them are made to sell rather than to purify, and will remove only the larger or mechanical impurities from the water. Others, while they work well at first, are exceedingly likely to become clogged, when the tendency is to punch at them to make them work faster, thus either poking a hole through them or cracking the filter-shell, so that a stream of water flows steadily through, just as impure as when it entered. Private filters, like boiling water, are only temporary ways of meeting conditions _which ought not to be allowed to exist at all_ in civilized communities, or in your own homes. A score of court decisions in all parts of the world have now held that the water company is legally responsible for all avoidable pollution of public water-supplies, and nine tenths of pollutions _are_ avoidable. FOOTNOTES: [13] These gases and salts are eagerly sucked up by the roots of plants, so that the soil bacteria are our best friends, changing poisonous decaying things into harmless plant-foods. They are the chief secret of the fertility of a soil; and the more there are of them the richer a soil is. [14] This makes fourteen times as many deaths from typhoid in proportion to the population as occur in Germany.