After carefully reviewing the subject, I do not know that I need qualify, except to express more confidently, the account I formerly gave you of those peculiarities, as consisting in the conjunction of dampness with organic decomposition.
It is in respect of these conditions—especially among dense urban populations, that the level of occupied ground, relatively to the nearest water-surface, becomes of primary importance. The low level, in itself, or rather in respect of the watery dampness which it implies, is not enough to localise the pestilence. To be afloat at sea might be the safest lodging.
The sub-district of St. Peter’s, Hammersmith, averages only four feet above high-water level; that of St. Olave’s, Southwark, two feet higher; yet among the former and worse placed of these two populations, the Cholera-mortality was only 18 per 10,000; while among the latter and better placed it rose to 196—multiplying nearly eleven times the minor phenomena of a lower level. So also within your own jurisdiction. Side by side along the river lie four of your sub-districts; three at the elevation of twenty-one feet, one at the elevation of twenty-four feet. The Cholera-mortality, if simply proportioned to level, should have been nearly the same for these four sub-districts, but somewhat less in the last one than in the first three. Yet contrary was the fact; for in two of these sub-districts the Cholera-mortality, for equal numbers of population, was 41⁄2 times as great as in the other two.
It would, therefore, appear that in certain low-lying levels—to constitute them favorable soils for the disease, there must be joined to their first condition of lowness (with the mere watery dampness which it implies) some other and second condition; one, which is of extreme frequency in such districts, though not essentially present there.
This second condition impends wherever there dwells at such levels a certain density of population; it mainly varies with the degree in which that dense population lives in the atmosphere of its own excrements and refuse. In this respect I cannot refrain from saying, that the giant error of London is its present system of drainage. Probably in considerable parts of the metropolitan area, house-drainage is extensively absent: probably in considerable parts, the sewers, from the nature of their construction, are very doubtful advantages to the districts they traverse: but the evil, before all others, to which I attach importance in relation to the present subject, is that habitual empoisonment of soil and air which is inseparable from our tidal drainage. From this influence, I doubt not, a large proportion of the metropolis has derived its liability to Cholera. A moment’s reflection is sufficient to show the immense distribution of putrefactive dampness which belongs to this vicious system. There is implied in it that the entire excrementation of the metropolis (with the exception of such as, not less poisonously, lies pent beneath houses) shall sooner or later be mingled in the stream of the river, there to be rolled backward and forward amid the population; that, at low water, for many hours, this material shall be trickling over broad belts of spongy bank which then dry their contaminated mud in the sunshine, exhaling fœtor and poison; that at high water, for many hours, it shall be retained[79] or driven back within all low-level sewers and house-drains, soaking far and wide into the soil, or leaving putrescent deposit along miles of underground brickwork, as on a deeper pavement. Sewers which, under better circumstances, should be benefactions and appliances for health in their several districts, are thus rendered inevitable sources of evil. During a large proportion of their time they are occupied in retaining or re-distributing that which it is their office to remove. They furnish chambers for an immense fæcal evaporation; at every breeze which strikes against their open mouths, at every tide which encroaches on their inward space, their gases are breathed into the upper air—wherever outlet exists, into houses, foot-paths, and carriage-way.
[79] I am informed that in large districts on the south side of the river, this retention of sewage is prolonged for two-thirds of every tide—sixteen hours out of every twenty-four.
To you, Gentlemen, as Commissioners of Sewers for the City of London, these remarks may seem superfluous; the rather so, as the worst evils of tidal drainage are not largely exemplified within your jurisdiction. But it seems to me of extreme moment at the present time, when very costly improvements of the metropolitan drainage are about to undergo parliamentary discussion, that the public should be well aware how indispensable such improvements are for the general health of London, and how important, in fact, they are to thousands who at first sight might think themselves little interested in their completion.
To some individual householder, dwelling at a high level, all concern in the subject may seem to terminate with the defluxion of his own sewage. So that his own pipes remain clear, little cares he for the ultimate outfall of his nuisance! Perhaps, if he knew better, he would care more. His gift returns to him with increase. Down in the valley, whither his refuse runs, converge innumerable kindred contributions. From city and suburb—from an area of a hundred square miles covered by a quarter of a million of houses, with their unprecedented throng of metropolitan life, there pours into that single channel every conceivable excrement, outscouring, garbage and refuse, from man and beast, street and slum, shamble and factory, market and hospital. From the polluted bosom of the river steam up, incessantly though unseen, the vapours of a retributive poison; densest and most destructive, no doubt, along the sodden banks and stinking sewers of lowest level; but spreading over miles of land—sometimes rolled high by wind, sometimes blended low with mist, and baneful, even to their margin that curls over distant fields. For, not alone in Rotherhithe and Newington—not alone along the Effra or the Fleet, are traced the evils of this great miasm. The deepest shadows of the cloud lie here; but its outskirts darken the distance, A fever hardly to be accounted for, an infantile sickness of undue malignity, a doctor’s injunction for change of air, may at times suggest to the dweller in our healthiest suburbs, that while draining his refuse to the Thames, he receives for requital some partial workings of the gigantic poison-bed which he has contributed to maintain.
The subject of these remoter effects I refrain from pursuing, as foreign to my present purpose. That on which I wish to insist is the character of the river, in its relation to the marginal sub-districts which it habitually dampens and occasionally floods with putrescent soakage, and in its relation to the sewers of low gradient which it converts (often with their adjoining soil) into the similitude and hurtfulness of cesspools. I wish emphatically to point out, that the several parts of London have suffered, and are likely again to suffer, from Cholera, in proportion as either this malarious influence is exerted on them, or other kindred miasms are furnished by their soil. And it is my belief, from such evidence as is before me, that the general liability of London to suffer the epidemic visitation will cease, whenever an efficient and inodorous system of drainage, conveying all refuse of the metropolis beyond range of its atmosphere, shall be substituted for our present elaborate disguise of an unremoved nuisance. I deem it right to state this explicitly: not only because it is my duty to give you, in simple truth, the conclusions to which I am led by careful reflection on the facts; but likewise because—for the credit of sanitary medicine and for your justification in the awful presence of a recurrent pestilence within your jurisdiction—it ought to be thoroughly known how much of the cause is common to the entire metropolis, and has not admitted of removal by measures of partial improvement. And the circumstances will perhaps excuse me if I repeat to your Hon. Court—represented as you are both in the Metropolitan Commission of Sewers and in Parliament, where this question must shortly be discussed—that the universal reform of our metropolitan drainage, at whatever imaginable pecuniary cost, is an urgent claim and necessity, unless this great city is again, as two centuries ago, to live under the constant alarm of increasing epidemic destruction.
Reverting, however, to the more especial relations of the disease within your territory, you will remember that, among your four bank-side sub-districts, two suffered in marked excess; their Cholera-mortality having been 41⁄2 times as great as that of the other two. The fact is instructive; because those two suffering sub-districts (though not of lower mean level than the others) were marginal to the valley of the Fleet, and were therefore exposed, more than any other part of your province, to the class of evils I have described. For a considerable part of this locality may be regarded as but recently[80] a creek of the Thames; its shelving banks, singularly foul from ancient misuse, though now built over and paved, undergo in their lower levels very considerable soakage; while those vast sewers which lie in the mid-channel of the former river, are more liable than any within your jurisdiction, to suffer injurious interference from the action of the tide. At every such interference, and at every current of air setting up the sewers, all gases generated in these large chambers would diffuse themselves, not only in the low level, but likewise widely east and west, up those important slopes which depend on this valley for their drainage. I can easily understand that the radical cure of this district may be possible, only as part of those metropolitan improvements to which I have adverted; but I do think it of supreme importance, in reference to any such visitation as we dread, that, during the next twelve months, there should be taken every precaution which technical knowledge can suggest, for restricting, even by palliative and temporary expedients, those mischievous effects which I have endeavoured to illustrate.