[49] It appears that the New River Company at present derives about two-thirds of its supply from the River Lea, and proposes to draw from this source a still larger proportion. Any chemical difference of quality in the City pipe-water (as between that supplied by the New River and that by the East London Company) would probably not exceed those limits of difference which prevail in respect of waters gathered _under varying circumstances_ from one and the same source. The pipe-water consumed in the City has for its general chemical character, that it contains a considerable quantity of carbonate of lime, held in solution by an excess of carbonic acid. To this and another salt of lime (the sulphate) the water chiefly owes the property which is complained of under the name of _hardness_: it is by reason of these salts, namely, that it decomposes a certain large proportion of whatever soap is used with it; preventing the formation of a lather, till those salts are exhausted by a wasted proportion of soap, by boiling or otherwise, and hindering to that extent the several purposes for which soap is employed. You are probably aware that soda is extensively used in the laundry, as an antidote to this objectionable quality of hard waters; and the excess of its employment tends, by corrosion, very observably to hasten the destruction of washed articles of dress. In the same measure as water possesses the property of decomposing soap, its utility as an universal solvent is impaired; it extends to various other substances which one seeks to dissolve in it (especially to many vegetable matters) that same disposition to waste them in the form of insoluble precipitates. Its conveniences for the purposes of cooking and manufacture are _pari passu_ diminished. Of the actual extent of which these disadvantages are sustained within the City of London, I have no means of forming an exact opinion; but statements are before the public (from the general correctness of which I have no reason to withhold reliance and belief) rating the pecuniary loss to the metropolis, in the two articles of soap and tea, at a very high figure. You will see from Mr. Taylor’s observations the proportion in which waste occurs, as regards one of these articles; namely that, for the production of a lather in washing, the pipe-water of the City of London, used without boiling, consumes from 13 to 19 times as much soap as distilled water would consume.[50]