The village of Canisteo, New York, has a hard spring water, the hardness being recorded by the State Department of Health as 162.8 parts calcium carbonate in a million parts of water. Clifton Springs water has a hardness of 208. Catskill, New York, which gets its water from a stream running down from the hillside, has a hardness of 22.1 or 140.7 parts less than Canisteo. Mr. G. C. Whipple says ("Value of Pure Water") he has found that 1 pound of soap is needed to soften 167 gallons of water when that water has a hardness of 20 parts per million, and that each additional part requires 200 pounds of soap to soften a million gallons. If Clifton Springs and Catskill should each use 100,000 gallons per day, the additional cost of the hard water, at five cents a pound for soap, would be 20 x 140.7 x 0.05 = $140.70, provided all the village water were neutralized with soap. Probably not over one fiftieth part of the water is so neutralized, so that the added cost of soap is actually about $2.80 a day. Whipple expresses this cost as _H_/100 = _D_, where H is the hardness in parts per million and _D_ is the cost in cents for every 1000 gallons used for all purposes. Thus Canisteo water costs 162.8/100 = 1.6 cents per 1000 gallons used, while Catskill costs only 22.1/100 or 0.2 cent on account of soap. This discussion is intended to suggest a comparison between a well of hard water and a surface supply of soft water, when both are available. It should arouse an interest in securing a soft water as well as a clear water, and the advantages of the softer water, in so far as soap consumption alone is concerned, are seen to be not inconsiderable. _Vegetable pollution._ The vegetable and animal matter is organic in its origin and nature, and their effect on water may be taken up together. Vegetable pollution is generally the result of decayed leaves, roots, bark, and such other vegetable tissue as would be likely to be found where the water-supply flows through a swamp or accumulates in hollows and depressions. This sort of water is likely to have a brownish or yellowish brown color, to have a slightly sweetish taste, and to be soft, that is, free from mineral solids. Usually such water can be used for drinking purposes without serious consequences. AEsthetically, it is objectionable because of its color, and the city of Boston has expended many thousands dollars in building channels around swamps and in providing artificial outlets for swamps, so that the color of the water collected on the watershed shall not show the color induced thereby. Water from the Dismal Swamp of Virginia is so discolored as to look like coffee, and yet, in the vicinity, it is much prized for drinking, and formerly great pains were taken to fill casks with this water when in preparation for a long sea voyage.