Rain, or the softest water, is better adapted than any other for washing and cleaning; but it must be filtered for drinking in large towns, as it becomes impure from the roofs and plaster of houses. The best water has the greatest number of air bubbles when poured into a glass. Hard water will become thick and foul sooner than soft water.
139. To purify Water for drinking.—Filter river water through a sponge, more or less compressed, instead of stone or sand, by which the water is not only rendered more clear, but wholesome; for sand is insensibly dissolved by the water, so that in four or five years it will have lost a fifth part of its weight. Powder of charcoal should be added to the sponge when the water is foul, or fetid. Those who examine the large quantity of terrene matter on the inside of tea-kettles will be convinced all water should be boiled before drunk.
140. Or, take a large flower-pot, and put either a piece of sponge or some cleanly-washed moss over the hole at the bottom. Fill the pot three-quarters with a mixture of equal parts of clean sharp sand, and charcoal in pieces the size of peas. On this lay a piece of linen or woollen cloth, large enough to hang over the sides of the pot. Pour the water to be filtered into the basin formed by the cloth, and it will come out pure through the sponge or moss at the bottom.
141. To purify River, or Muddy Water.—Dissolve half an ounce of alum in a pint of warm water, and stirring it about in a puncheon of water from the river, all the impurities will soon settle to the bottom, and in a day or two it will become quite clear.
142. To purify muddy Water of Rivers or Pits.—Make a number of holes in the bottom of a deep tub; lay some clean gravel thereon, and above this some clean sand; sink this tub in the river or pit, so that only a few inches of the tub will be above the surface of the water; the river or pit water will filter through the sand, and rise clear through it to the level of the water on the outside, and will be pure and limpid.