Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 4, 1802).djvu/335

Rh apt to crack in the fire, if it be wrought into basons, &c. of a larger capacity, the patentee recommends such vessels to be manufactured of equal parts of the clay and sand above mentioned. She farther states other proportions of clay, loam, &c. which may be employed according to the size of the bason or other vessel; and for a specification of which, the reader will consult the 2d vol, of the "Repertory of Arts," &c.

To conclude this important subject, we shall state a few other simple methods of restoring putrid water to its original purity.

Dr. directs a small cask, open at both ends, to be placed within a larger vessel, the head of which has been taken out: clean sand and gravel are then to be put into both vessels, so that the level of the sand in the inner cask be higher than the bed in the intermediate space between the two barrels; sufficient room being left for pouring in the water. A cock should now be placed in the external cask, above the gravel or sand; and somewhat lower than the surface of the materials in the interior vessel. The water is poured in, at the top of the cask last mentioned; it sinks through the mass of sand; and, after passing through the bed in the intervening space, it ascends, so that it may be drawn off perfectly sweet and clear:—when the surface of the gravel becomes loaded with impurities, it should be removed, and fresh sand be substituted.

According to the experiments of M., $1 1⁄2$oz. of pulverized charcoal, and 24 drops of the sulphuric or vitriolic acid, are sufficient to purify $3 1⁄2$ pints of putrid or corrupted water, without communicating to it any perceptible acidity: he directs the oil of vitriol to be first mixed with the water; after which the charcoal must be added; but, if the sulphuric acid be omitted, it will be requisite to employ a triple portion, or $4 1⁄2$oz. of charcoal.—When spring-water has acquired an unpleasant, hepatic flavour, it may be greatly improved by filtring it through a bag half filled with powdered charcoal. This substance may again he dried, and pulverized, when it will answer the same purpose a second time; and, if it lose its purifying effect, by repeated use, such property may be recovered, by making it red-hot in a close vessel.—Prof. recommends carbon to be reduced to fine powder; a spoonful of which must be mixed with a pint of stagnant, corrupted, or bad water: the whole should be well stirred, then suffered to stand for a few minutes, and afterwards passed slowly through filtering paper. He remarks, that the same powder will serve repeatedly; and, after drying it, he advises travellers to keep it closely corked in a bottle; because the influence of the air would render it useless.—Lastly, if either of the expedients already described, cannot be conveniently adopted, the putrid tendency of water may be corrected, by mixing vinegar, or acid of lemons, with the corrupted fluid; and, in case any quantity of the latter should have been accidentally swallowed, its injurious effects may be obviated, by immediately taking small, but repeated, draughts of vinegar.  WATER,, or Hydrocephalus, is a collection of serum, either between the bones and common integuments, when it is