Chambers's Journal of Popular Literature, Science, and Art, Fifth Series, No. 32, Vol. I, August 9, 1884

No. 32.—Vol. I.
Price 1½ d.
SATURDAY, AUGUST 9, 1884.
Water bears a very important part in relation to the human system and preservation of health. It combines with the tissues of the body, and forms a necessary part of its structure. In the case of a man weighing one hundred and fifty-four pounds, one hundred and eleven would consist of water. It enters very largely into the composition of our food. Although water is so important a factor in our existence, and although its vitiation often gives rise to that deadly pestilence, typhoid fever, yet, strange to say, there are comparatively few people who possess any trustworthy information respecting its primary sources and purest forms. The object of this paper will be to afford our readers some useful hints respecting the various kinds of water and their relative purity, also to mention certain wise precautions requisite in order to avoid impure water.
The first great source of water is the ocean; the sun shining upon the surface, its heating rays combine with and send out a certain amount of vapour. The atmosphere, like a sponge, absorbs the vaporous water, forming clouds, which are driven by the wind east, west, north, and south. When the clouds arrive in a cooler atmosphere, the vapour condenses, and descends in the form of rain or snow, being ultimately absorbed into the earth, giving rise to different varieties of water; or it pours down the mountains, and forms rivulets, and ultimately rivers. Thus we have rain, spring, and river water. We may here mention that Dr Normandy discovered a process by which sea-water can be distilled and rendered fit to drink. In nature, water is never found perfectly pure, as that which descends in rain is to a certain degree contaminated by the impurities contained in the air, as spring-water is by contact with various substances in the earth. These impurities are not always perceptible. Thus, the clearest and brightest waters, those of springs and pellucid rivers, even when filtered, are never pure. They all contain a greater or less percentage of saline matter, often so much so, indeed, as to form what are termed mineral waters. Amongst the purest natural waters hitherto discovered is that of the Loka in North Sweden. It contains only one-twentieth of a grain (0.0566) of mineral matter per gallon. The water supplied to the city of Edinburgh contains from seven to fourteen grains in the gallon; whilst that of the Thames near London contains about twenty-one. Rain-water, if collected in the country, is the purest; but when obtained in or near large cities, becomes impure from passing through a vitiated atmosphere.