The present imperfections of knowledge forbid me to cite, as definite causes of disease, the contaminations to which I have adverted: I cannot say to you--pointing to our classified list of sickness and mortality, _this_ depends on drinking the diluted drainage of Hertford, _that_ on the contributions of Ware. Indeed I know that, under the influence of the river and the atmosphere, very considerable changes occur in the materials thus furnished, tending eventually to render them inert; and if injury to life occur from their ingestion, it is probably only under peculiar and exceptional conditions, increasing their quantity, or delaying their oxidation. In protesting against their continued distribution as articles of diet, I therefore insist less on inferences deducible from medicine, and shall probably have the concurrence of your Hon. Court in grounding my appeal on the common principles of taste. On the incidental contaminations to which the pipe-water consumed within the City becomes liable, by reason of its storage in receptacles both foul in themselves and surrounded by causes of foulness, I have already addressed you; and I have shown to you the dependence of this evil on the system of intermittent supply as adapted to the houses of the poor. Of other sources of water-supply existing within the City of London, there are many of small extent in the form of superficial springs. These are eagerly sought after, sometimes from a distance, on account of their coolness and sparkling condition. In the Appendix[51] you will find an account of one of these waters--that in the vicinity of Bishopsgate church, which is very much drunk in that quarter of the City. Any praise given to it illustrates exceedingly the fallacy of popular judgment on such subjects, and shows how easily those qualities of coolness and freshness, which are absent from stored waters, impose on the palate, and induce a preference to be given to waters which are relatively most objectionable. [51] See page 170. The chemical faults which belong to our London pipe-water are possessed in a far greater degree by this water of Bishopsgate pump, and the latter has moreover some vices which are absent from the former; but the vapidity and fustiness of water which has been stored in cisterns are so repugnant to the taste, that the water chemically preferable is not in practice preferred.