1868.] 'Water, 397 WATEK. THIS fluid is one of the few positive necessities of man ; and without it the wretchedness of his condition would be quite as great as in the absence of air or heat. In cases of shipwreck, the want of water is the most fearful of all the torments which suffering man has to bear. Such is the imperative demand of ' thirst, that, in the absence of fresh water, the unfortunate is driven to the drinking of salt water, and this, producing frenzy, terminates his existence in horrible spasms. On the parched, sandy desert, when the supply of water has given out, how the traveller yearns for that oasis, in the midst of which he will find the cooling spring to quench his burning thirst. What greater horror awaits the damned than the want of even one single drop of that element upon which man, in the midst of his abundance here, so seldom spares a thought ! The luxury of pure drinking-water is one that he alone can realize who has been compelled to use the turbid water of the Missouri, the Ohio, or the Missis- sippi. Those who have lived in St. Louis can thoroughly relish the clear and lim- pid beverage of the more favored locali- ties, and bear testimony to the merits of the heaven-born draught, in its purity. It would be only reasonable to expect that, in our day of scientific advance- ment, the subject of pure drinking-water would be one to draw forth all the at- tainable advantages, which a thorough knowledge of the subject gives. But such is not the case. The fact is, the ancients were far in advance of us, if not in the knowledge of theoretic philoso- phy, certainly in the practical processes proving its truth. They knew that purity is the natural state of water, and that every thing, which tends to turn it from its primitive condition, is unnatu- ral or foreign to it. Turbid rivers are so, because of the extraneous matter they have acquired, and hold in solution, whether mineral, or vegetable. The presence of mineral matter ren- ders the water hard, and unfit for cook- ing, or washing. And the presence of too much organic matter renders the water utterby useless for drinking pur- poses, and very unwholesome, even for cooking with. It is said, that marsh-water itself may be made drinkable, by steeping in it certain herbs, or, by rubbing the kettles, it is boiled in, with bitter seeds, or herbs. In China and Japan they use, for this purpose, the tea plant ; in India the strychnos potatorum; and the bitter almond on the banks of the Nile. There are other difficulties, which the best of water is liable to ; and those arise, sometimes unaccountably, under apparently, the most stringent system of precaution. Some years since, the citizens of Bos- ton were suddenly disgusted with their favorite Cochituate water on account of the villanously fishy taste and smell acquired by the decomposition of vast numbers of animalcule, setting free an oil, which imparted the unpleasant quali- ties. The city of Amsterdam was in 185G subjected to the same annoyance with the addition of a reddish deposit. A commission of scientific men, apjjointed to examine into the matter, discovered, that it arose from the decomposition of masses of Algse-conferras, and other water plants. It is ascertained, that letting such water remain, for some hours, in con- tact with large surfaces of iron, renders such, and other, impurities insoluble, or it will altogether destroy them. But perfect filtration must be resorted to, afterwards, before such water is fit for use. Now, this brings us to the considera-
