waters. But in this estimate we do not include an equal amount of urine, for the following reason : This liquid, when stale or putrid, has the remarkable property of precipitating the earthy salts from their solution, or in other words, it makes hard waters soft. Although the fastidious may revolt from the use of water thus sweetened to our palate, it is perhaps fortunate that this mixture is daily taking place, for otherwise the water of this city would become, in a much shorter space of time than it actually does, utterly unfit for domestic purposes. We cannot take leave of this part of the subject without adverting to the various and contradictory opinions which have been expressed on the purity of our waters. We must impute to long use and the influence of habit, the opinion that our water is sufficiently pure for domestic purposes. We have known our citizens, upon going into the country, express a marked disrelish for pure spring water. The popular expression on such occasions is, " This water is like wind — there is nothing substantial in it ; nothing to bite upon." This powerful influ- ence of habit is exemplified even among animals. At one of our watering places, (Sara- toga,) cattle have been observed to prefer the strongest mineral water known, to that de- rived from a pure source. The coldness of our pump waters is another cause which conceals their impurities when swallowed. This may be tested by allowing it to stand until it has acquired the ordinary summer temperature ; its various ingredients become then manifest, palpable. These impurities are not caused by the additional heat ; they exist at all times in the water ; their presence is only disguised for the moment by its coldness, and its injurious properties are in no wise diminished. Your inquiry as to the effects of impure water upon the human system, falls more properly within the province of the medical philosopher than the naturalist ; we do not, therefore, feel ourselves called upon in this place to enter upon this subject farther than to state, that in several diseases, such as dyspepsia, and those bowel complaints of children, which carry off so many annually, the cure is retarded by the daily use of bad water. In the latter disease, in particular, the mode of cure often resorted to, is a change of air, which is supposed to be the chief agent in removing the disease. It is within the knowl- edge of some of the committee, that the use of pure water alone, without removal, has produced an almost immediate and beneficial change. From all which has been previously stated, you will learn that it is the unanimous opinion of the committee, that no adequate supply of good or wholesome water can be obtained on this Island, for the wants of a large and rapidly increasing city like New York. The various perforations which have been made, in the absence of all other proof, would sufficiently establish this position. These have been undertaken without any acquaintance with those immutable laws of nature, which regulate the position of rocks, and their utter uselessness is now sufficiently obvious. They- may be carried to any assignable depth in this rock, and when completed, will be merely reservoirs to receive the drainage from above. Both the citizens and city authorities now went to work in earnest, and in December a report was made by Mr. Samuel Stevens, in behalf of the committee of fire and water, CROTON AQUEDUCT. HI that reviewed the whole ground, the various plans that had at different times been projected, and indicated that, which, in the judgment of the committee, was most feasible. The possibility of supplying' the city from springs or wells on Manhattan Island, is considered, and discarded. Independently of the uncertainty both as to the quantity and quality of the water which might thus be obtained, the multiplication of wells and steam engines that would be required to produce the supply needed — estimated at 4,000,000 gallons, daily — was a decisive objection. The Artesian well of the Manhattan Company, at Thirteenth-street, which is considered as a very successful experiment, yields but 20,000 gallons daily, and it would require 200 such wells, with steam power at each, to supply four million gallons. The plan for relying on the Croton, admitted to be that which ensured the most abundant supply, was put aside by reason of the great cost of the work, and because the Bronx river presented an adequate resource nearer by, and at less expense. The minimum daily supply from that river, was estimated by accurate measurement and survey, made by Canvass White, in 1826, at 4,302,720 gallons, and by damming the Rye ponds, an additional supply