nent-a dire disgrace to London, the metropolis of the orld. Mr. Bazalgette's voice, however, may not have en raised in vain. The Chief Commissioner has delared that the drainage plans are still to be submitted o the ablest engineers in the country, when Mr. Bazalette's views may yet find support. The western district contains about twenty-one miles. The surface is low, much of it being but slightly above high-water mark. Mr. Bazalgette reports," In 1854, Mr. Haywood and I recommended for this area, mainly in the score of economy, works for purifying its sewage waters, and then discharging them into the Thames," -instead of conveying the sewage of 21 square miles hrough the heart of Westminster and London to the Lea. He adds," Since then, extensive experiments, which have been made in several places, all tend to confirm the statement, that sewage matter can be separated from the water in which it is dissolved without creating a nuisance, and the water may, by this means, be rendered elean and inoffensive. Thus it was that, in the year 1854, we were induced to recommend the construction of sewage works in a suburban locality, removed from houses, viz., in the fields on the banks of the river west of Kensington canal. "In making that recommendation we assumed the sewage to be valueless; but we had ascertained that the cost of the process of purification would be very much less than that of conveying the sewage to high water at Barking Creek. And this latter circumstance mainly influenced us, although the increased engineering difficulties attendant on the other scheme had some share in forming our decision. "Since the date of that report objections have been raised to the establishment of deodorising works in the locality mentioned." Whichever plan be adopted, it is proposed to make the western sewer capable of being ultimately extended to Brentford. The sewage of that and of other populous towns in the neighbourhood will, in the mean time, continue to pour their sewage into the Thames above the bridges. 66 Supposing the sewage of the western district to be conveyed to deodorising works near the mouth of the Kensington canal, a branch from Chelsea hospital would have to be constructed." The sewage would be raised by pumping either into the low level sewer, or to the sewage works. "If it is decided to deal with the sewage locally at the sewage works, it would be raised at the Kensington canal fifteen and a half feet, requiring 153 horse-power. But, if conveyed to the out-fall, it would have to be raised twenty and a half feet, requiring for that purpose 328 horse-power. The cost of pumping, in the latter case, would amount to £15,120 per annum, but only to £8,900 per annum if the sewage were deodorised near Kensington canal. capable of being adapted to a variety of outfalls into the Thames, or to the utilisation of the sewage at Barking Creek and Woolwich Marshes, or even nearer to London, and the Thames thus purified at a less cost, the reservoirs at those places being dispensed with, substituting for them deodorising works, and discharging the purified watersinto the Thames at all times of the tide." "This process would entirely remove the sewage from the river in a practical point of view. A further saving of nearly half a million might be effected by terminating the sewers and establishing deodorising works nearer to London, say in the Greenwich Marshes and the West Ham Marshes, which would accomplish the object desired without creating a nuisance." Now let us examine whether the deodorisation cannot be better performed elsewhere. Taking first the western district, I will give an outline of the deodorising works as they would be established near the outlet of the Kensington Conal. 1st. The pumping engines would be of a less power than that requisite to raise the sewage into the low-level sewer opposite Vauxhall. 2nd. The deodorising canals, the elevators, and filter frames, would be entirely built in; so that the solid deposit would be discharged direct from the filters into covered barges, without any previous contact with the outer air, and be at once conveyed to depôts on the banks of the river, far beyond the limits of the metropolis. 3rd. Were it decided to flush or scour during dry weather the low-level sewer, passing along the Strand and Fleet-street line, with the effluent water, one deposit canal alone would be employed. But should it be found preferable to discharge it into the river, a second canal, two hundred feet in length, would be necessary; and after passing through it, the effluent stream would be found transparent, and free from taste and smell. The next point at which deodorising works might be introduced is near the river Lea. The position of these works ought unquestionably to be on the City side of the Lea, the passage over which river, by a tubular aqueduct for the high level, and by a conduit beneath the river bed for the low level sewer, will be extremely costly and difficult of execution. The expensive extension and the huge reservoir in the marshes would be entirely dispensed with. The deodorising system might also be applied to the southern drainage scheme by works at Deptford Creek, the pumping-station there proposed being most conveniently situated for the purpose. The necessity would thus be avoided of conveying the sewage from Clapham and Putney to the reservoirs in the marshes, and the sewage of Greenwich might be brought down by its natural fall to the Deptford works, just as the Chelsea sewage was to the western works at Kensington canal, leaving the sewage of Woolwich and the lower part of the line to be treated separately, if at all. "The saving effected by not conveying the sewage to I will now give the estimate of cost for the drainage the outfall, together with the diminution of engine- and conveyance of the sewage down to Erith Reach, as power, would amount to £8,059 per annum, advantages now under the consideration of the Metropolitan Board, which induced me still to recommend the cheaper pro-and compare it with the same drainage modified by cess. Should the sewage at some future time attain a marketable value, it would go toward liquidating the expenses of extracting it from the water." The saving on the further extension to Erith Reach will again increase this amount, which, together with the reduced cost of the deodorising process, would now amount to a saving of £12,000 a year on the western district alone, and this may one day be further increased by the sale of the manure. Having quoted from Mr. Bazalgette's earlier reports his repeated recommendation of the deodorising system for the western district, let me now read an extract from a much later report, dated the 25th September last, after Sir Benjamin Hall had twice rejected, on behalf of the Government, outfalls approved by the Metropolitan Board. He says:-" The approved drainage scheme is deodorizing works. (See Table in following page.) Hitherto I have confined myself to showing how easily the system which Mr.Bazalgette himself recommends at the Kensington canal, for an area of twenty-two square miles may be extended to every other part of the remaining eighty square miles of his projected plan. But if I have succeeded in imparting to my hearers a small share of the conviction I myself derive from the success of the Leicester works, and have satisfactorily shown that deodorizing works can be placed, even in the most densely crowded localities, without the possibility of any well-grounded objection being raised against them, it may be asked, whether considerable advantage would not accrue from augmenting their number; and whether, by placing them in the centres rather than at the extremities of the lines of intercepting sewers the consequent diminution of distance, Produce from filter presses, 300,000 tons annually, which, if sold at only 28. per ton, would cover the working expenses. £1,205,919, then, would appear to be the amount of capital to be saved by adopting the deodorising system over the whole of the metropolitan drainage scheme; and I will not shrink from comparing my portion of the estimates, step by step, with those adopted by the Board. As far as I can separate the amounts representing the cost of drainage, &c., for the western district alone, they state of its shores, unless that very necessary undertaking be carried out. I go further, and maintain that the embankment itself should enclose the deodorizing canals, the vaulted roofs of which would form a platforın available for roads or any other purpose. The embankment, in fact, is a key to the whole position. It will cut off the communication between the present sewers and the river, and, at the same time, furnish, without disturbing the streets, not only a site for deodorizing the sewage waters, but the best site, namely, one at or near the present mouths of the sewers, whilst the works would offer no interference to the roads, quays, or warehouses erected over them. The capital required to carry out any system for unprofitably conveying the sewage of the metropolis down the river, would, in conjunction with the funds produced by the new wharves and docks, suffice to effect this great undertaking Until the embankment was considerably advanced, the sewers entering the Thames between London and Westminster Bridges would continue as now to pour their filth into the river, but all the enormous sewers above and below the bridges might at once be purified by the erection of local works which could be brought into operation within six months from the time at which the ground was placed in the hands of engineers. How many years must otherwise elapse before any portion of the metropolitan sewage will be directed from its present course. One striking advantage in treating the sewage locally is, the facility which it offers for meeting, at any future time, the necessities of an increasing population in any particular district. On Mr. Bazalgette's plan, preparation is to be made at once, at an enormous increase of expense, for an addition of one million to the present population, an estimate which never may be realised, or at least not in the quarters anticipated. Nothing that I have proposed would interfere with the high and middle level intercepting sewers, works comparatively inexpensive, and offering no engineering difficulties. I would only observe, that the sewage conveyed by those sewers should be treated locally, and the purified water, when needed, supplied during dry weather to the flushing of the lower and less rapid system of sewers. Although several members of the Metropolitan Boards have visited the works at Leicester for their individual satisfaction, the authorities of the metropolis have not attempted to acquaint themselves on better ground than hearsay evidence, with the facts which have resulted from the Leicester experiment. It is a reproach to all parties that no official knowledge is possessed upon a subject which is associated at Leicester with such changes in the Bills of Mortality, as are exhibited by the report of the Officer of Health. High scientific opinions are not wanting in support of the system. I will read the following letter in proof of what I state : "Chemical Laboratory, Guy's Hospital, September, 15th, 1851. "SIR,-We have read with great attention your pamphlet, describing the patent process for producing solid manure from sewage water, and think that the plan which you proposed for collecting the sewage of towns and speedily converting it to a profitable and useful manure, excellent. "The chemistry is properly explained, and the descriptions clear and intelligible. "We can state of our knowledge, and from our own experiments, that by your process the nitrogenous organic matter, as well as the phosphoric acids, dissolved or undissolved, would go down and be retained in the solid deposit; while the water, after the precipitation is completed, will be discharged in a limpid state, and free from the offensive matter which it previously contained. "The avoidance in your process of long exposure to the air, and the absence of artificial heat, ensures the separation, in the best manner, to prevent loss of the fertilising matters contained in the sewage water. "We consider your process has, in fact, these advantages over every other plan which has been proposed-it provides for the immediate and rapid sewerage of a district at all periods; it prevents the contamination of a river, or other sources of water supply by removing all noxious animal and vegetable matters; it provides for a speedy deodorisation, separation, and drying, of the solid and useful parts of the sewage; and, lastly, it furnishes to the agriculturist a cheap and useful manure. Wishing you success in a practical form, 46 "We are, yours, very truly, "ARTHUR AIKIN. F.L.S. "ALFRED S. TAYLOR, M.D., F.R.S. "T. Wicksteed, Esq., &c., &c." the case. manner, of all things just the thing to supply as manure for the growth of the food of that population. The Irish fed very much upon potatoes, and potatoes grew well in Ireland, because the effete matter of the potato feeder was exactly suited for the growth of that crop; and, in like the population of the metropolis of this country would be best provided with food suited to it by the application of the sewage of the metropolis to the land. The 12,000 tons of nitrogen consumed in the food of its inhabitants was capable of being applied to the growth of a similar representative of food if we followed Nature's teachings. He was in the first instance surprised at the With such opinions and results in favour of the system, statement that the inhabitants of London, in maintaining I demand, on public grounds, that further inquiry be made their vitality, consumed about 12,000 tons of nitrogen into the facts which I have alleged. Let chemists be ap-annually: but, ignorant of the mode of arriving at this pointed by the Government to analyse the sewage water at result by Mr. Cooke, he had made the calculation on his every stage of the operation; let a commission be appointed own data, and came to the result of 11,768 tons, which to visit and examine deliberately and frequently the works was very near the amount stated in the paper. at Leicester, at all hours, and judge whether the results Mr. J. B. LAWES said, that he read before this Society, herein stated have been exaggerated, and if they are found about two years ago, a paper upon the sewage of Lonto be fully borne out, let not the provisions of the act of don, in which he expressed an opinion that it would 1855 be tortured into preventing the admission of not be possible, by any process hitherto discovered, to limpid water into the Thames, when no objection has manufacture a solid manure from sewage, which should hitherto been raised to the discharge into the river of be remunerative both to the manufacturer and to the storm waters, which after passing for miles in common agriculturist. This subject was very fully entered into sewers cannot be remarkably pure and inodorous. at that time. Indeed, the interest taken in it was so great, that the Council of the Society was kind enough to devote an extra night to the discussion. Mr. Wicksteed's pamphlet was then before the public, in which he endeavoured to show that a profit of 22 per cent, could be obtained upon a capital of one million, by applying to the sewage of London that process which had since been carried out at Leicester, and described this evening by Mr. Cooke. Mr. Wicksteed considered that his solid manure would sell for £2 to £2 13s. Od. per ton. It was, however, argued by him (Mr. Lawes) and others, that the chemical composition of the manure would not justify Mr. Wicksteed in assigning to it a greater value than a few shillings per ton. It must be gratifying to those who, like him (Mr. Lawes), considered that the value of any manure could be determined by its chemical composition, to find that this opinion had been confirmed that night by Mr. Cooke. This sewage deposit was no longer a valuable artificial manure, but it was to be ranked with lime, chalk, clay, &c. Mr. Cooke had said, " that it would find purchasers at a low price, when it could be obtained at an easy and short carriage; and that, by judicious arrangements, it might sell for rather more than it costs." The great objection to Mr. Wicksteed's process was this, that while increasing the sewage by an enormous bulk of worthless matter, it failed to arrest the greater portion of that which was most valuable in the sewage, which, consequently, flowed back into the sewers or rivers. It was well known to chemists that lime would not precipitate The CHAIRMAN said it was now his duty to invite dis- ammonia or its salts from a liquid containing them. cussion upon this subject. At the present stage he would Mr. Cooke endeavoured to meet the objection by saying, only say that he agreed with the author of the paper in that in using Mr. Wicksteed's process they did not deal the importance of the question being solved as to the with highly putrescent sewage abounding in ammonia. beneficial application of the sewage of the metropolis, Professor Way, however, held a different opinion; he exand the prevention of its entire waste. When they re-amined sewer-water from places in the centre of London, collected that the whole system of vegetable and animal | from Barret-court and Dorset-square, and stated that all life depended one upon the other-that vegetables lived the nitrogen in the liquid state seemed to be in the form of upon carbonic acid, water, ammonia, and certain mineral substances that these afforded food to animals during life, and were again resolved, by the effete matter during life and decay after death, into the same substances, viz., carbonic acid, water, and ammonia, it was not, he thought, a wise policy on the part of the metropolis to send away all that matter to feed sea-gulls and sea-lions, in order that it might be brought back again from Ichaboe in the form of guano. Instead of this general and wasteful distribution of our treasures throughout the world, it would be far better to use them economically and productively at home. He would mention one philosophical fact. The effete matter of a population was That ordinary sewage has high manuring properties is universally admitted, and I have shown how it may be employed, both economically and without contaminating the atmosphere. Again, the cheap manure in which the deposit can be produced in a solid form, yet promises to render its manufacture self-paying if not even lucrative. For my own part, I think that ultimately such will be But farmers are slow in appreciating the value of any manure that does not possess strong fertilizing properties, and the quantity produced must for a time exceed the demand. Its value, however, for compost or "nitre beds" is beginning to be appreciated, which alone will open a wide field for its employment. Above a thousand tons have been taken by the farmers near Leicester during the past week, and further applications have been made, but at a very low price. Leaving the question of marketable value, my object this evening has been to represent the great facitities for, and advantages in, deodorizing the sewage water of the metropolis before putrescence is in full activity, and the restoration of the water either in a pure state to the river, or the use of it after deodorization for the purposes of inoffensive irrigation. That the sewage water can be sufficiently deodorized and purified by lime alone without causing the slightest nuisance, is a great fact, and I can see nothing but prejudice or penuriousness that can prevent its adoption. DISCUSSION. ammoniacal salts; that in one case 84 per cent., and in the other 89 per cent. of the whole ammonia in the sewage existed in the soluble state. While, therefore, he (Mr. Lawes) might lament, with Mr. Cooke, that thirty million pounds worth of ammonia had gone to waste in the City of London during his life, he (Mr. Lawes) could not admit that this waste would be stopped by the application of Mr. Wicksteed's process. Mr. Cooke had, perhaps wisely, abstained from furnishing an analysis of his manure, but he (Mr. Lawes) would, however, venture to quote one which had lately been given him by Professor Voelcker, Professor of Chemistry to the Royal Agricultural College, Cirencester :— 100.77 And containing nitrogen equal to 0-60; ammonia, 0.72. Mr. E.CHADWICK, C.B., said that, on the statement made by Mr. Cooke, that "it behoved the authorities generally to consider whether the effluvium from an extensive area saturated with sewage, poisoning the atmosphere by putrifying and steaming during the heat of the summer, might not be as injurious to the health of Kent, aye, to the metropolis itself, as the most efficient subterranean removal of sewage might be beneficial," it was to be observed that by one set of authorities, at the least, the foundation of such apprehensions had been care fully examined, and provisions made to meet them; and it was, doubtless, the duty of those who had the responsibility of new works to re-investigate the subject, and to examine the works in actual operation. The first scheme for applying the sewage of the metropolis to other towns was proposed by the late Mr. Smith, of Deanston, and was simply an application of the practice at Edinburgh of applying it by submersion. The result of the investigation of the Board of Health was to establish sanitary objections to this system, as well as objections of an agricultural and economical nature. The deodorising power of soils might be illustrated by such common facts as that, when the cook had an "oniony" knife, it was the practice to put it in garden mould, where it was soon perfectly deodorised. But by Professor Way, and by Mr. Huxtable, those deodorising powers of the soils had been demonstrated scientifically and experimentally, by passing sewage, or mixtures of decomposing animal or vegetable matter, through a sufficient stratum. Most persons who lived in the neighbourhood of the parks, at the period of top-dressings, had been annoyed by the foul odours arising from this operation. Indeed, he had known frequent illness occasioned by them. Similar evils were at times experienced during the heavy dunging and top-dressings of market-gardens with decomposing animal manures. Great loss also ensued; agriculturists agreed that two-thirds, or three-fourths, escaped in a gaseous form. The mode of preventing this loss and nuisance was not to apply chemicals, but simply to perform the work of disintegration at once by Mr. G. F. WILSON, F.R.S., said, having seen the works at Leicester in operation, he could bear testimony to the apparent perfection of the numerous mechanical arrangements there, and to the complete manner in which the sewage was deodorized and disinfected. The chemical part of the process was less complete; through the undecomposed nitrogenous matter, some compounds of urea, such as the oxalate and nitrate phosphates, soap suds, and some other good manure could be saved by the lime process, precipitation, and filtration, yet ammonia, when once formed, could not be so. He thought, however, that in one chemical point of view the lec-drain, and lay down upon it pipes for the distribution of turer had not done Mr. Wicksteed's process justice; the sewer manure, and then re-let it, prepared for cultivathough lime would not fix ammonia, other bodies known tion, with a supply of the manure, on lease, and apply the to chemists would; and there was no doubt that greater surplus rents to the sanitary improvement of the town." chemical knowledge applied to the subject would intro- In 1853, Mr. Chadwick addressed a letter to the Home duce those bodies either in substitution for, or in addi- Secretary, in which he stated that there were ten towns tion to, the lime-magnesian limestone, for example. where inoffensive and beneficial distribution, by flexible Now it seemed to him that Mr. Wicksteed's process and pipe and jets, might be anticipated at an early date; apparatus afforded the great present good of rendering and, in 1856, the same gentleman read a paper at the sewage entirely innoxious and inoffensive; the further, Free Trade Congress of Brussels, in which he spoke of though less important, present good, of separating a con- a hundred towns in such a manner as to lead to siderable portion of the fertilizing matter; and the great the belief that they were about to derive crops and future good of supplying in operation a beautifully com- revenue from their sewage.-[Mr. Chadwick dissented.] plete apparatus, with appliances for precipitation, for -At any rate, such was the impression of Mr. Walker, conveying out the precipitate, and its separation, by fil- of Rugby, of himself (Mr. Sidney), and many others. tration, from the water with which it was mixed, all at In this paper, at least, two examples only of enlightened once available when the body to fix the ammonia made cultivation were cited-the well-known liquid manure its appearance. Now he (Mr. Wilson) could not think, farm, of 170 acres, at Tiptree (where his worthy friend, even if the chemical knowledge would allow it (and we Mr. Mechi, never grew good corn crops, or good root crops, had now great scientific chemists) that the common until he followed the example of his neighbours, and sense of the country would not interfere to prevent any gave his wheat 30s. an acre of solid guano, and drilled such monstrous plan as that by which the enormously in a good dose of Lawes' superphosphate with his manvaluable matter of the London sewers would be carried gold), and the sewage manure farm of Mr. Walker, at and allowed to run to waste into the German Ocean. Rugby, where, on 200 acres of grass land, on a wonderIf we waited until a combined mechanical and chemi- fully porous soil, a very good effect was produced by the cal process arrived at perfection, we should wait for liquid sewage in summer. Here, then, after all, were ever. How did great manufactures rise? When a pro- just two towns, or, rather, villages, using town sewage cess had attained a moderate degree of perfection, it on the Deanston plan, Watford, where the machinery was put into operation; then improvements after did not as yet work successfully, and Rugby. But improvements were naturally suggested. The great the sewage manure theorists maintained that the thing was to get a good practical starting point, and absence of demand for the fertilising streams of cities was the meeting would, he thought, agree with him that to be attributed to the stupidity of the British farmer. Mr. Wicksteed had, at the very least, advanced thus far But had the farmer been standing still during the last at Leicester. sixteen years? During that period a million sterling Mr. S. SIDNEY said this was the third time that the had been invested in manufactories for producing anvalue of sewage manure had been discussed by the nually hundreds of steam engines, threshing machines, Society of Arts. On the first occasion, he (Mr. Sidney) drills, horse-hoes, clod-crushers, ploughs, harrows, &c., characterised as wild exaggerations the poetical view which were eagerly bought up. During that period milwhich Mr. Mechi took of the refuse of cities. On lions had been sunk in draining, paid for by farmers' the second occasion, Mr. Bennet Lawes, in a most able rents; hundreds of thousands of tons of guano, costing paper, exhausted the chemical part of the question, and from £10 to £15 a ton, had been consumed. Manufaccame to the conclusion, that a distant limited applica- tories of another costly manure, superphosphate of lime, tion of sewage manure to grass land in a liquid state, had been established in every great town and every agwas its only profitable use; and now Mr. F. Cooke, in ricultural district. These manufacturers imported bones, his very candid paper, was content to take manufactured bone ashes, and burned flesh from South America; they solid sewage, at from 2s. to 4s. per ton, a price that ransacked even the battle-fields of Europe for the same would not bear the cost of carriage, as he (Mr. Sidney) invaluable material; they imported apatite from Norhad shown in former discussions. This theory of the way; and they did all this while sewage lay at their enormous value of town sewage was not new. The doors, offered to them gratis, and yet they did not find late ingenious Mr. Smith, of Deanston, was the author it worth while to accept it. After bringing forward of a theory, that town sewage could be converted into other instances in support of his views, Mr. Sidney said a source of revenue-a theory which the late Board of that in thus following out the history of British agriculHealth had employed, in order to bribe many towns to ture it was impossible to doubt that the profitable use of enter into costly and unprofitable schemes of town liquid manure must depend on special and exceptional drainage. In 1848, Mr. Smith, of Deanston, in a report circumstances, as, for instance, where it could by gravicirculated under the authority of the Board of Health, tation be cheaply applied to grass land, of a quality suffiwrote " Assuming that 5 cwt. of sewer water is equal ciently porous to absorb it. At Rugby it flowed away to 24 cwt. of guano-that the sewer water of every town rapidly enough; yet even there it could not be all used, was worth £1 per head per annum (that would give three and the river was polluted. But few soils were like that millions sterling for London); and that, therefore, such of the Rugby farm. If he were asked why we neglect an income annually would provide a fund for the improve- British, and send so far for Peruvian guano, at more than ment of all towns in a manner corresponding with the most one hundred times the price of the home production, he enlightened views with respect to sanitary regulations.' ."" would answer, why do we drink China tea instead of A very little inquiry served to show, that while 24 cwt. British herbs, Eastern sugar instead of British honey? of guano was worth 30s., and would produce an increase Why do we wear American cotton and Italian silk, instead of six bushels of wheat per acre over ordinary crops, of British home-spun? Why do we prefer rosewood to the same quantity of sewage water was all but value- British oak? Why toast our friends in foreign chamless. Nevertheless, in the first report of the Board of pagne instead of the domestic gooseberry? Because the Health, dated July, 1849, it was said, "That in the foreign article was cheaper at the higher price. local works which it is necessary to execute for the sanitary improvement of towns, an entirely new system of sewerage must be combined with a new system of house drainage, with a new system of water supply, and with a new system of removing and of applying the refuse of towns to agriculture." And Local Boards of Health were recommended to enclose waste land, Mr. Sheriff MECHI begged to state, in a very few words, the results of his own practical experience on this subject, and, in the first place, he would remark, that the earth was the best and cheapest deodoriser that they had. So effective was it that where he had applied large quantities of liquid manure of the strongest description, saturated with the dead bodies of animals in |