Townsend presented a report from the Lyceum of Natural History, in New York, in answer to queries addressed to that Society, relative to the probable supply and quality of water which Manhattan Island might furnish. As a disposition then existed in some quarters, and perhaps even still lingers, to rely upon the water and wells of the island, the facts and reasonings of the Report (drawn Up, we believe, by Dr. Dekay,) cannot be uninteresting, however startling to the fastidious, some of the statements may appear.

Of the Purity of the New York Waters. All waters, it is well known, which are not decidedly of a mineral character, are divided into two classes, hard and soft. With the latter we have nothing to do in the present communication, as none of it occurs in the thickly settled parts of the island. Hard waters are such as contain a sensible quantity of foreign ingredients, the chief of which are Garb, of Lime, Sulph. Lime, or (Plaster of Paris,) Mur. Sod. (or Common Salt,) Mur. Magnes, Iron, and extractive or animal and vegetable matter. Weaccordingly find that all the water in the city contains these, and occasionally other ingredients. For the following analysis of pump waters in various parts of the city, the Committee are indebted to one of its members. When it is recollected that the hardest spring water seldom contains so much as one thousandth part of its weight of any foreign body in solution, it would seem that the term, mineral water, would be a more correct designation for the ordinary waters of this city.