Page:Popular Science Monthly Volume 25.djvu/258

248 prevention of putrefaction and fermentation of certain liquids. It is with this view that the interiors of barrels intended to hold wine, beer, or water, are carbonized. Certain odorous culinary operations are rendered inodorous by the introduction of a fragment of charcoal into the pot. The efficacy of charcoal as a filtering material is due in a great measure to the oxidizing action of the oxygen contained in its pores."

In the article on vegetable charcoal in the "National Dispensatory," the writer says: "The most fetid gases disengaged by putrefaction are among those which are the most abundantly absorbed by charcoal, viz., ammonia, sulphureted hydrogen, and sulphurous acid, and the oxygen contained in the charcoal combines with the other deleterious substances and generates new and inodorous compounds." Buck says, "All varieties of carbon formed by the destructive distillation of vegetable or animal matter possess the property of removing organic matter from solution." Fowne's "Chemistry" says of charcoal, "It is said to absorb ninety times its volume of ammonical gas." But sufficient authorities have been quoted to prove the high estimate in which vegetable charcoal is held as a filtering material by chemists and sanitarians. Careful experimenting with it has satisfied me of its efficacy and practicability. It is efficient, clean, easily obtained by any one, and so cheap that after a few weeks' use it can be thrown away, and a clean supply substituted, and the cost need not be taken into consideration. Animal charcoal possesses valuable filtering properties, but it is very expensive, difficult to be obtained, and is so associated in the minds of the people with dead horses and the bone-yard that a strong prejudice exists against it. I have thus tried to show in this paper—1. That clean drinking-water is essential to health. 2. Some of the well-established results of drinking polluted water. 3. The various filtering materials that have been used, with their merits and objections. 4. The superiority and availability of vegetable charcoal as a filtering material.

In conclusion, in answering the question, "How, then, may we obtain clean drinking-water?" I would answer, by filtering the water slowly through properly adjusted vegetable charcoal placed in an earthen receptacle of some kind so that the water will not come in contact at any stage of its passage through the filter with metal of any kind. Cool the filtered water by placing ice under or around the vessel in which the water is contained, but do not put the ice into the water, or its impurities will be liberated by melting and contaminate it. Acting on these suggestions, I believe clean drinking-water may be obtained in any family, and, with clean water, less sickness.