In further connexion with my present subject, I would also solicit attention to the fact that the sanitary purposes of drainage are but imperfectly achieved, where the outfall of sewerage is into a tidal river passing through the heart of a densely peopled metropolis. I should be stepping beyond my province, if I were to say much respecting the schemes now before the public for dealing with the difficulty to which I here refer, inasmuch as those schemes involve questions of engineering and machinery, on which I am incompetent to form an opinion. But I can have no hesitation in stating it as a matter greatly to be desired in the City of London, that the noble river which ebbs and flows beneath its dwellings should cease to be the drainpool of our vast metropolis; and that the immeasurable filth which now pollutes the stream should be intercepted in its course, and be conveyed to some distant destination, where instead of breeding sickness and mortality, it might become a source of agricultural increase and national wealth.[17] [17] This subject is more particularly dwelt upon in the last Report; page 261. I would venture, likewise, to express an opinion that the City of London is peculiarly interested in the accomplishment of this great public work, not only on general grounds relating to the conservancy of the river, but likewise and especially on sanitary grounds, by reason of the large bank-side population, subjects of the City, who now, instead of deriving advantage from their nearness to the stream, are constantly disgusted and injured by its misuse. While the consideration of this most important measure is pending, I would invite attention to some circumstances, by which even the present evil is needlessly aggravated. In the first place the sewers are of defective length, so that during the ebb of the tide their contents, as they escape, are suffered to flow in a stream of some length across the mud of the retreating river. The stream, together with the mud which it saturates, and the open mouth of the sewer, evolve copious and offensive exhalations, and I would recommend that measures be taken for abatement of the nuisance. This purpose, as concerns the sewer, would be fulfilled by the addition, in each instance, of a sufficient length of brick or cast-iron work, to prolong the canal beyond low water mark; but the great extent of mud which is left uncovered at each tide, and which during the present pollution of the river is a source of extreme nuisance and of disease, constitutes an evil for which no remedy can be found till the stream shall be narrowed and embanked.