REP ORT OF THIE BOARD OF SEWERAGE COMMISSIONERS OF THE CITY OF CHICAGO, FOR THE HALF YEAR ENDING JUNE 30, 1860. CHICAGO: PTJBLISHE:D B'Z TFHE BOA:RD_ 1860. REPORT OF COMMISSIONERS. SEWERAGE COMMISSIONERS' OFFICE, | Chicago, 111., July 30, 1860. To the Hon. MVayor and Common Council of the City of Chicago, Illinois: THE Board of Sewerage Commissioners beg leave to present theiri report for the half year ending 30th June last. The amount of work accomplished is exhibited in the appended table of lengths of Sewers laid, and the expenditures therefor in the financial statement. In our previous report we alluded to the condition of our river as affected by the sewage, and intimated our intention to institute some inquiry as to the possibility and probability of an enlargement and deepening of the- canal to such an extent as to create a constant current from the Lake to the'Illinois River. The results of this inquiry are exhibited in the report of the Chief Engineer of this Board, appended hereto. Other matters of great interest in connection with this subject are alluded to in the Engineer's report, to which we invite careful attention. The extracts from documents relate to the London sewerage works, and the condition of the river Thames will interest all who have given any thought to the subject. It is not necessary, and indeed is scarcely proper for us to discuss the importance of the proposed canal enlargement, any further than our own work seems related to it. Its bearings upon the commercial interests of our city have long been seen, and have been considerably discussed heretofore. 4 It is our hope, that by presenting a new and important advantage to be attained by this work, the attention of your honorable body and of the public- may be again so turned to it that efficient steps may be taken to push it forward with all practical despatch. In the mean time it is the opinion of this Board that it is expedient to delay, for the present, the construction of the canal from the Lake to the South Branch, proposed in our original plan, for the purpose of renovating the water of the river. The estimate for that work, with the necessary wheel and engine, was sixty thousand dollars ($60,000.) This expenditure would be rendered in a large degree useless, so soon as the deep cut of the Illinois and Michigan Canal should be made. Should the condition of the river seem to demand some extra means of purification, we hope to be able to make an arrangement with the canal company to pump for us so much as may be needed to change the water sufficiently. If this can be done for a moderate amount over the interest of the cost of the permanent work proposed, it will be an obvious gain. Should the deep cut be indefinitely postponed, it will be necessary for us to revert to our original design. We hope, however, for a better result of the present consideration of the subject. It seems to us that no subject of so great importance, in various ways, to the material interests of our city, is now asking attention. Is it not desirable that some measure looking to the accomplishment of so great a good, should be matured for presentation to our next Legislature? In connection with this matter of the effect of the sewage upon the water of the river, we ask careful attention to the report of our Chief Engineer and the accompanying extracts from recent English documents. These give the latest information in our possession of the state of opinion on this subject, among those who have given it the most attention, bringing to its investigation the best abilities and qualifications. 5 Length in feet of Sewers laid up to June 30th, 1860. z _ XC SOUTH. NORTH. W ES T. TOTAL. ~ Previous In 1860. Previous In 1860. Previous In 1860. to 1860. to 1860. to 1860. 6.. 3,895 86 285 1,007 5,273 5 361.. 4,675.. 14,362 2,501 21,899 4...- - v 2,010..... 2,010 4 1,952.... 1,892 2,854 297...... 6,995 3 11,863 732 3,160................. 15,755 22 16,270 371................. 16,641 21 6,102 612.......6,102 2 18.846.. 29,574 870 25,426 3,630 78.346 1 40,741 12,220 15,703 4,648 17,148 2,813, 93,273 96,135 13,323 58,899 8,458 59,528 9,951 246,294 Or 468 miles, of which 6 miles have been laid this year. Also 919 catch basins with connecting pipes for receiving surface water from the streets, and 1,824 man-holes for entering the sewers, have been built. Nineteen hundred and seventy-two (1,972) house drains (pipes) have also been laid, and are now in use, connecting with the new sewers. These were laid at the cost of the owners of the lots drained, and under the direction of the Sewerage Commissioners. 6 FINANCIAL STATEMENT FOR THE HALF YEAR ENDING JUNE 30, 1860. _R I, C E: I P T S. Bills Payable. Money loaned from Marine Bk.; etc.. $40,000.00. City of Chicago. On acc. of Sewerage Tax, 1859... 53,808.66 House Drains ace. Permits...................... 778.75 Private Drains ace. Materials................... 689.02 Interest and Exchange. From Marine Bank....... 259.88 Wm. Hildebrand. Int. on Sinking Fund mortgage. 530.00 Hiram Joy.. " " " " 44.74 Ashley & Norris. Coupons acc.................. 24,017.50-$120,128.55 Divided among the Sewerage Districts, viz: South District................ $45,580.52 North "..................... 33,458.05 West "...... 41,089.98-$120,128.55 Balance Cash on hand January 1, 1860, as per last statement... 67,912.09 Total.......... $188,040.64 E X PEN- D I T IU RI: S. Advertising ace. Proposals, etc.................. $105.04 Books and Maps ace. Sundries.................. 1.97 Bricks ace, "................. 9,044.00 Cleansing Sewers ace. "................. 5,192.31 Construction " "........... 24,521.82 Cement " ".................. 1,531.70 Implements " ".................. 138.62 Instruments ace. Repairs....................... 5.00 Office Expenses ace. Rent, fuel, etc... 483.33 Office Furniture ace. Chairs..................... 15.00 Sewer Pipes ace. Sundries.................... 11,609.15 Salaries " ".................... 7,212.25 Stationery "...................... 84.15 Transportation ace. " 137.50 Coupons ace. Due 1st Jan., 1860................ 24,017.50- $84,109.34 Expended and charged to the Sewerage Districts, viz: South District......... $26,468.64 North ".......... 26,603.43 West ".31,037.27-$84,109.34 Balance Cash on hand July 1, 1860......................... 103,931.30 Total................ $188,040.64 7 I N D IE B T ED IDN E S S. Bonds. Issued, sold and unsold............. $850,000.00 Bills Payable. Money loaned from Marine Bk. etc. 40,000.00 Sinking Fund..................... 50,423.44 Wm. Smith & Co. Money advanced for Taylor street Sewer........................... 125.00 Gould & Bro. Money advanced for Wabash av. Sewer................................. 25.00 H. L. Munroe. Money advanced for Wabash av. Sewer.............................. 50.00 John Tyrrell. Money advanced for Wabash av. Sewer................................. 25.00 Coupons ace.................................. 90,392.01-$1,031,040.45 Incurred and charged to the Sewerage Districts, viz: South District........... $383,206.82 North............ 289,509.81 West.. 358,323.82-$1,031,040.45 C R IEIDITS. Bills Receivable. Sundries.................... $8,699.10 Walker & Cutting. Bricks to be delivered....... 679.50 Hiram Joy. Sinking Fund mortgage........ 6,453.82 Timothy Wright. " "........... 10,520.42 Wm. Hildebrand. " "........... 11,141.04 Cash on hand............................... 103,931.30 Chicago Gas Light & Coke Co. Three man-hole covers................................... 12.00 Patrick Smith and his sureties. Contract work West Division........ *................. 1,296.95 Ashley & Norris. Bal. cash on deposit in N. Y.. 2,016.68 City of Chicago. Sewerage Tax, 1860.......... 77,664.60 American Exchange Bank, N. Y. Bonds and cash on deposit............................ 91,096.40 Marine Bank of Chicago. Bonds on deposit..... 46,000.00 House Drains ace. Junctions to be refunded by permits................................ 4,604.50- 364,116.31 TOTAL INDEBTEDNESS on account of the work at this date.. $666,924.14 Materials, Implements, etc., on hand............. $11,901.00 Eighty-seven thousand dollars ($87,000) six per cent. bonds sold at par of seven per cents, amount less than face................................. 9,074.10 Interest, Exchange and Commissions acc......... 38.583.06- 59,558.16 Amount forward............. $607,365.98 Brought forward.................. $607,365.98 Add Sinking Fund and Coupons acc'ts, raised by City Tax..... 140,815.45 ACTUrAL COST of the work executed, July 1, 1860, including cleansing Sewers and all preliminary expenses for Surveys, Maps, Plans, etc...................................... $748,181.43 B O N D S. 1st loan Bonds, six per cents, sold................ $87,000.00 "' " seven" "............... 413,000.00 — 500,000.00 2nd loan " " " "................ 254,000.00 " " " " issued, unsold....... 96,000.00- 350,000.00 Total issued, sold and unsold.......... $850,000.00 Bonds, purchased for Sinking Fund and cancelled, 7 per cents.. 10,000.00 $840,000. 00 All of which is respectfully submitted. PHILIP CONLEY, J. D. WEBSTER, Sewerage S. LIND, -'S) Commissioners. S. LIND, STATE OF ILLINOIS,) COUNTY OF COOK, SS. CITY OF CHICAGO. ) On this fourth day of August, A. D. 1860, before me, the undersigned, a Notary Public, in and for said City, in said County and State, personally came the above named Philip Conley, Joseph D. Webster and Sylvester Lind, Sewerage Commissioners of the City of Chicago, and to me personally known, and having by me been first duly sworn, did depose and say that the foregoing report and statement by them severally subscribed, is a true and just report and statement of facts,. according to the best of their knowledge and belief, and further say not. Witness my hand and Notarial seal the day and year last [L. s.] above written. JAMES B. BRADWELL, Notary Public. APPEND IX. SEWERAGE COMMISSIONERS' OFFICE, I Chicago, lll., Feb. 7, 1860. E. S. CHESBROUGH, ESQ., Chief Engineer Board Sewerage Com'rs: SIR: You are aware that it has for a good while been regarded as desirable by many interested in the commercial prosperity of our State and City, to make a channel by which the water of Lake Michigan may flow directly to the Illinois River. To effect this, it is proposed either to cut down the summit of the Illinois and Michigan Canal, or to make a new channel through Mud Lake to the DesPlaines River, and then to deepen the channel of that stream sufficiently to answer the purpose. The obvious bearing of this scheme upon the sanitary condition of the Chicago River, as affected by the sewage of the city, renders it desirable for this Board to obtain whatever reliable information can be had in reference to its practicability and expense, and the probability of its being carried out. As bearing also upon the same point, it is desirable to obtain information as to the proposed pumping arrangements for the supply of the present summit level of the Canal-as to what amount of water the Canal Company expect to pump 10 from our river daily, and for what portion of the season of navigation. It is presumed that data for the desired information exist in greater or less completeness in the Canal office at Lockport. You will please proceed to that place at your earliest convenience, and investigate the above mentioned subject, and report the results of your examinations to this Board, with such considerations as may seem to you important in their bearing upon the welfare of our city. I hand you herewith a letter of introduction from the State Canal Trustee to the Secretary of the Canal Board, in charge of the office at Lockport, which it is presumed will gain you access to the records of that office, and also such assistance and information from the Secretary as may be compatible with his other necessary engagements. Should further surveys be necessary to a full and fair elucidation of the subject, you will report that fact, with an estimate of the expense of making them. Very respectfully, Your Obedient Servant, J. D. WEBSTER, Acting Commissioner. By order of the Board. PREPORT OF ENGINEER. OFFICE SEWERAGE COMMISSIONERS, Chicaco, June 30, 1860. To the Board of Sewerage Commissioners: GENTLEMEN: In conformity with your instructions of February 7th,. I proceeded, in company with one of your Board, Capt. Webster, on the 9th, to Lockport. On making known the object of our visit to Mr. Gooding, the Secretary of the Canal Board, we were very kindly received, and much gratification was expressed by that gentleman in the prospect of the question of improving the Canal, or the navigation of the Illinois River, being brought again before the public. So much information, obtained from surveys and estimates, together with the results of his experience in connection with the Canal, both as Constructing Engineer, and since as Secretary of the Board, was communicated by Mr. Gooding, that it became apparent very soon there was no necessity for further surveys, at least so far as the subject concerned your body. In order to ascertain as you desire, the probability of the present Canal being so altered as to be fed from Lake Michigan, without artificial power, or of a partially new Canal being made, and supplied in the same way, it is necessary to know the probable cost, and the advantages that may reasonably be expected from such a work. Mr. Gooding estimates the cost of lowering the present 12 Canal, so as to feed from Lake Michigan, as originally intended, at $2,000,000. This estimate is based upon actual measurement of the quantities of different kinds of work to be done, and also, on the supposition that operations could be carried on in summer as well as in winter. Should the whole of the work have to be done in winter, its cost would greatly exceed $2,000,000, but by how much Mr. Gooding has not estimated. With regard to the cost of making a new channel through Mud Lake to the DesPlaines River, and then deepening the channel of that stream sufficiently to answer the purpose of a canal, no reliable estimate has yet been made. The work of cutting the channel between the South Branch and the DesPlaines has been going on for four years already, at a trifling cost, by means of the surplus waters of the Des Plaines, which during floods are diverted outward. In this way, during the last four years, a navigable channel of three miles in length has been obtained. How long it will take to reach the DesPlaines must depend very much upon the character of the soil intervening, and of future seasons with regard to rain. It is known that for a portion of the remaining distance the soil is not so favorable as it has been, there being a hard gravelly bar across the line of the new channel; but it is believed that an excavation through this and some stiff clay at other points, by hand or machinery, would insure the further cutting of the new channel by floodwaters, as heretofore. Whenever this channel shall be cut through to the Des Plaines, a great saving in the cost of lowering the summit level of the Canal to that of Lake Michigan will have been effected. Beyond that point, in Mr. Gooding's opinion, it would cost more to keep the water out of the present channel of the river than would be saved in excavating it to the required depth, instead of lowering the summit level of the Canal. The bed of the river is so rocky at several points that it could not be dredged to the required depth. 13 Two other projects have been talked of for enlarging the Canal, so as to make it navigable for steamboats; one with a channel two hundred feet wide and six feet deep, and the other with a channel of the same width but twelve and a half feet deep. The probable cost of constructing the former of these has been estimated by Mr. Gooding at. $10,000,000, and the latter at $20,000,000, but of course he does not consider these sums as anything more than a rude approximation, and they are not intended to include the probable cost of locks and other necessary works, at and below Lockport. There does not appear to be any reasonable probability of an enlarged Canal either six or twelve and a half feet deep being undertaken at present, or very soon; but the demands of this city and State for greater facilities of transporting the grain, lumber and other products of this region, a generation hence, if the future development of our country is to be at all in proportion to the past, must eventually cause such a work to be commenced. This, together with improvements it would be quite practicable to make in the channel of the Illinois River, would afford navigation for steamboats of five hundred tons or more burthen between this city and St. Louis. Mr. Gooding has made a careful examination of the River to it:s mouth, and finds its total fall much less, and its capability of being improved without locks and dams, far greater than he had supposed; and is decidedly of the opinion that the surest way to bring about desirable improvements in the Canal would be to improve the navigation of the Illinois River first; because the Canal as it now is, is more reliable than the River, and is capable of accommodating four times the amount of trade it now has. With the improved navigation of the River, he thinks the business of the Canal would soon equal its maximum capacity, and thus demonstrate the imperative necessity of improvements now considered only desirable. His estimate of the cost of making this improvement of the River is $500,000. The total fall from LaSalle to the mouth of the River is 14 only twenty-eight feet, or about one and a half inches per mile, distributed very uniformly throughout the whole distance, and not unequally in rapids and intervening pools, as was formerly supposed. This condition of the River is considered remarkably favorable for improving its navigation without resorting to locks and dams; to which the inhabitants along the River, as well as those interested in steamboats, are said to be very strongly opposed. The means of improving the navigation as contemplated in the above estimate, are, deepening the channel by dredging in some places, and, building dams from islands and shoals to one of the main shores in others. By such means, Mr. Gooding believes that without an increased supply of water from the Lake or other sources, the River could be so improved as to afford navigation sufficient for all the wants of the Canal until it shall be enlarged. In the event of carrying out the proposed improvement of the River navigation, Mr. Gooding would recommend, as a means of increasing the present capacity of the Canal for accommodating traffic fifty per cent., and of greatly diminishing the cost of transportation, to lengthen the locks fifty feet each, and to carry out certain other improvements that would increase the depth of water, all of which, including the lengthening of the locks, he estimates would cost about $250,000. Of the different Canal plans, the lowering of the present summit level would seem to be the only project for which there is any probability that funds could be raised at this time. What advantage would it possess if carried out over the Canal in its present condition, especially after the completion of the improved and enlarged pumping works now in progress at Bridgeport? Could it accommodate any more business than it does now? These are important questions, and should be carefully looked into, before deciding upon such an improvement. In answer to the first, it may be said that the cost of maintaining the pumping works would be saved. 15 In answer to the second, it is believed that no greater accommodation to the traffic of the Canal would be afforded by lowering its summit level than now exists, if the pumping works are properly maintained. The probable cost of maintaining the pumping works, is, for raising 10,000 cubic feet of water per minute for twentyfour hours, as per estimate of Mr. Guthrie, $144. The new works will be capable of supplying 25,000 cubic feet per minute; or in case of an accident to either engine or wheel, the other engine and wheel could supply one-half this quantity. The average number of days per annum, for which pumping has been required during the past twelve years, is forty-six, which, multiplied by $150, would be $6,900. Mr. Guthrie estimates the value of the new works, when completed, at $80,000. The annual interest on this, at seven per cent., would be $5,600. Something should be allowed for repairs and deterioration, and ten per cent., or $8,000, will be supposed sufficient. Something must also be allowed for the general management of the works while in operation, and care of them when not, and for various contingencies-say $1,500, making in all the sum of $22,000 per annum. The foregoing estimates are based upon the supposition that the supply hitherto obtained from the Calumet Feeder is not to be cut off by draining operations in Indiana, against which it is understood that an express understanding was had between that State and the State of Illinois. (See page 10 of the Canal Trustees' Circular, No. 12.) But there is reason to fear that the State authorities of Indiana will disregard this understanding, and the Canal Company will be powerless to enforce it. Should the Calumet Feeder be cut off, the above estimate ought to be increased to about $45,000, or perhaps more. The interest on the estimated cost of lowering the present canal, $2,000,000, at seven per cent., would be $140,000 per annum, or more than three times as much as the estimated cost of maintaining the pumping works, including interest on their cost, even if the Calumet Feeder should be cut off. 16 Judging from the foregoing estimates, it would appear that decidedly the most economical way of providing for the proper accommodation of the traffic of the Canal, is to depend upon the pumping works. Yet the advantages to be derived from lowering the present Canal are very important, although it would be difficult to show that they would be an equivalent for their extra cost. Besides avoiding the liability of having to suspend business in consequence of a serious accident to the pumping works, although such an accident is exceedingly improbable, it would be of considerable importance to the city, and to mill owners at Lockport, and below, to have a constant stream of water passing up the South Branch and down the Canal, during the coldest weather in winter, as well as during the warmth and drought of summer; and what is of more consequence still, it would be the first and most important step towards an enlarged Canal. In view of the foregoing statements, it does not seem advisable for your Board to take any steps at present towards constructing a canal, or other work, for driving water from the Lake into the South Branch, to purify the river-because, 1st, if the Canal should be lowered at its summit level, such works would be useless; 2d, if the Calumet Feeder should be cut off, it would be necessary to create a constant stream up the South Branch during most of.the season of navigation, by pumping, if the Canal should not be lowered; and 3d, if the present Canal should not be lowered, and the Calumet Feeder should not be cut off, the experience of the past twelve years shows that pumping is necessary about forty-six days a year, on an average, to keep the Canal in constant navigable order during the busy season. To all who observed the effect of pumping on the appearance of the water in the main River and South Branch last summer, it was evident that it would be sufficient to remove and prevent any offensive smells that might otherwise have been caused by the emptying of the Sewers into the River: at least for some years to come. Should the necessities of the Canal Company not re 17 quire them to pump so many days as would be desirable for the benefit of the city, and it is not likely that they would, it would be better to pay the Canal Company, to keep their pumping works in operation during about ninety days a year, the interest on the cost of constructing the proposed works for driving Lake water into the South Branch together with the cost of maintaining them, than to construct the proposed works. Thus, in connection with what the Canal Company would have to do, pumping operations might be carried on during threefourths of the time, though not continually-for six months in the year, say from May 1st to November 1st, the only time during which any serious inconvenience could arise from the effect of sewage on the River. Sometimes in the coldest weather of winter, the water of the River, when covered with ice a foot or more in thickness, becomes offensive to the smell; at least offensive gases are generated somewhere, and they make themselves very sensibly felt wherever they find openings in the ice. No detriment to the public health is found at such times, however. Another and very important reason why it would be best to postpone the construction of the proposed works is, the desirableness of waiting some five or six years to learn the result of the gigantic works now constructing in London for intercepting, pumping up, deodorizing, and if possible, utilizing the sewage of that great metropolis. No one can glance at the different plans proposed for the consideration of the Boards intrusted with this subject, and the discussions respecting them, without feeling that the vitally important question as to what should be done with the sewage matter of large cities, is far from being satisfactorily settled yet. Hitherto the only improvements on a large scale have been the removal of sewage from where it would be a nuisance to the many to where it would be offensive to the few. Small towns only have been able to utilize it for agricultural purposes without serious loss. Many intelligent persons are now looking in the very opposite direction from that which has 2 been taken in London, that is, to correcting the evil at the fountain head by the construction of impermeable receptacles at the houses, and the use of such deodorizing substances as would not destroy the agricultural value of the matter to be removed. The writer of the article on Sanitary science, just published in the Encyclopedia Britannica, thinks that if as much skill and labor had been expended in this direction as in the other, a far better result would have been obtained. A great deal has been said and written with regard to the effect of discharging the Sewers of London into the Thames, upon the health of that city, much of which has no bearing upon the object of this Report; but it is believed that the following extracts will furnish a very good idea of the different opinions held by those whose knowledge and official positions should entitle their views to the highest consideration. Extract from pp. 7 to 9 of Report, dated July 31, 1857, of Messrs. GALTON, SIMPSON and BLACKWELL, to SIR BENJAMIN HALL, First Conmmissioner, etc. London. "Pollution of the River Thames. " In addition to the flow from the sewers into the Thames, there are other serious sources of pollution which were brought to our notice in our visits to the outfalls of the sewers, and to which it is necessary to direct attention. At almost all the wharves and manufacturing premises on the banks of the Thames, great nuisances arise from the privies, urinals, foul drains, etc., which communicate directly with the river. At the dung wharves and other places, large quantities of objectionable matter are frequently left on the foreshores to be washed away by the tide. " A similar extent of pollution prevails in the docks, canals and inlets which communicate with the Thames. We have also witnessed, on several occasions, most objectionable foul 19 matter being thrown into the river from barges in various parts; and from observations of the state of the water, our decided conviction is that large quantities of foul and polluted water and other liquids are occasionally let off from chemical works, gas works, and many other manufactories, not only directly into the river but into many of the sewers and watercourses which drain into it. These practices are of common occurrence, notwithstanding the efforts of the conservators of the Thames to prevent them. In order to obtain an exact knowledge of the effect which the continued flow of polluted matter has had in diminishing the purity of the Thames, we requested Dr. Hofmann, L.L.D., F.R.S., Chemist to the Museum of Practical Geology, and Mr. Witt, F.C.S., assistant Chemist to the Museum of Practical Geology, to undertake the analysis of specimens of Thames water, selected from various points between Teddington Lock and Rainhamn creek, as well as the analysis of samples taken at the same time from the mouths of sewers. " The results of these analyses, which were performed with great care, are shown in the very able communication of these gentlemen, which is attached to this report. 1" The general conclusions, however, to which these samples lead, appear in the following table, which contains the analysis of the more polluted specimens of river water, compared with the water from the mouths of the sewers: > 4z i RIVER TVATER. I ShWERs. ^ Ad;,' 3 _a XanC o n4.a ~ o -C;r4 Organic.. 1-844 1-9921 2359 1*937 2 194 2 032 2 059 2-738, 3 987 17*75 16 117 Mineral.. 238067 20'124 238672 23'496 23'676 25'649e23281 46'11 40'146 4;'23 51'804 TOTAL.... 2 91122 ll1626081 25 433 25.870 27681125 34048 848 44.133 64*98 67.4921 " X The small difference in the degree of impurity at Kew Bridge and at London Bridge is at first sight remarkable, and must be accounted for by the fact.that the whole of the sewage which flows into the river at low water, and during the first hours of the flood, is carried up by the tide into the higher parts of the river." 20 "It appears from this table, that the mean amount of organic matter contained in the specimens of river water was equal to about three-fourths of the amount of organic matter contained in the Earl sewer, and that the mineral matter in the river water was half that in the sewer; and that, as compared with the Fleet sewer, the quantity of organic matter in the river was as 1 to 8 in the sewer, the total impurity of the river to the total impurity in the sewer being as 1 to 2.6. "We collect from the report of Dr. Ilofmann and Mr. Witt,' to which we particularly beg to call attention, that "'* Since the quantity of dissolved organic matter is so small, the unwholesome character which it imparts to the water must arise chiefly from the peculiar condition in which it exists in the water. The opinions of chemists are divided as to the manner in which it exerts a deleterious effect upon the animal economy; but it is now generally admitted that the substances which constitute the organic matter of water act injuriously by no means in consequence of being poisonous themselves, but by undergoing those still imperfectly understood processes of transformation called decay and putrefaction, to which all animal and vegetable matter is subject when no longer under the control of vitality, in animals or in plants. These putrefactive processes either give rise to the formation of poisonous bodies, or - and this far more probable -they act simply as ferments, exciting similar processes.of decomposition in the substances composing the living animal organization. Decay and putrefaction are remarkably accelerated and facilitated by heat, and it is in fact during the comparatively short:season of hot weather that the inconvenience arising from the presence of dissolved organic matter in the river water is particularly felt. The small amount of this matter, which is scarcely perceived in winter, and which during spring and in the early part of summer is perfectly harmless, becomes decidedly mischievous soon after the hot weather has set in. " The share which the dissolved organic matter has in the generation of those deleterious emanations which rise from the river during the hot season cannot be doubted. A portion of Thames water which has been allowed to deposit all the suspended matter, which has been filtered through sand or paper, or even animal charcoal, or which has been treated with lime, and thus been rendered transparent, colorless and inodorous, when exposed to the air for a day or two during the hot weather, rapidly undergoes putrefaction, which in the first place manifests itself in the exhalation of an offensive odor, and gradually exhibits all the well known appearances presented by putrefying substances, not unfrequently with the development of some of the lower forms of organized beings which generally attend these processes. The water gradually becomes slightly turbid, and after a time a quantity of insoluble matter collects at the surface in the shape of a thin froth. The water has now become clear again; every trace of color and taste, or odor, has disappeared; the process of putrefaction is accomplished. " The phenomena to which we allude here are well known to those engaged in storing Thames water on board ship, where this putrefactive fermentation and subsequent purification of the water is frequently observed. "' Processes of a perfectly analogous character, and following each other in similar succession, are accomplished throughout the entire river, and during the whole year, but more particularly so during the hot summer months. We have already pointed out the fact that numerous analyses by very different observers, and extending over a considerable period, have undoubtedly proved that the amount of this dissolved matter is extremely small. It has been shown, moreover, that its amount is not very perceptibly greater at London or Westminster Bridge, where the water of the river looks so dirty, than at Kingston, Kew and Richmond, where it presents so beautifully clear and inviting an appearance. Why then is 21 the proportion of organic matter compared with the water in which it is contained is small, but that it is very pernicious, in consequence of its peculiar liability to putrefy;. for when water contaminated with sewage has been completely filtered through sand, paper, or even through animal charcoal, and by that means been rendered perfectly colorless, clear, transparent and inodorous, or after it has been treated with lime, it speedily begins, especially in hot weather, to ferment and putrefy, and becomes decidedly mischievous. "It would also appear that the black mud from the sewage contains a considerable quantity of organic matter, which is most deleterious; an immense mass of this foetid mud has accumulated in the bed and on the banks of the river, and it is continually supplying to the water large amounts of soluble matter in a state of putrescence, and contaminating the atmosphere with most offensive emanations. It is probable that the unhealthy condition of many towns on the sea coast is caused by deposits from the sewers, of mud of this character. it, we may ask, that the effects of these putrefactive decompositions become so intolerable on the banks of the Thames in the immediate neighborhood of London, when compared with those perceptible in the higher portions of the river? "It is obvious that the greater surface of the river as it traverses the metropolis, together with the agitation to which it is constantly subjected by the navigation, but especially by the steamboat traffic, as well as its tidal movements, must considerably facilitate and accelerate the progress of putrefaction; it is also evident that the quantity of soluble matter which, in consequence of the increased rapidity of putrefaction, is constantly being removed from the water, is as quickly and constantly replaced by the discharges of the sewers. These conditions alone would be sufficient enormously to increase the intensity of the process of putrefaction in this part of its course, and consequently to multiply the quantity of offensive emanations to an intolerable and dangerous degree. " But the river in the neighborhood of London contains an additional and even more formidable element of mischief in the black mud which subsides from the sewage, and which, in spite of the tidal movements of the river, has accumulated to a considerable degree, and is daily more and more accumulating in the bed of the river, so much so, indeed, that the continuation of the process would lead to the formation of deposits which, in future geological ages, might prove a source of manure scarcely less valuable than our beds of coprolites, phosphorite, and even of guano itself. This black mud contains a very considerable quantity of organic matter of a most putrescible kind. Alternately immersed in water, and exposed to the action of air, which, in consequence of its porous condition, it absorbs in large proportions; this mud unites all the conditions favorable for the most active putrefactive fermentation, evolving not only most offensive gaseous emanations, but diffusing also a large amount of putrescible soluble matter through the river, which supplies additional material to the process of decomposition which is going on in the water itself. " We cannot but emphatically insist upon it, that the formation of this mud deposit in the river appears to us by far the most serious evil which results from the discharge of the London sewage into the river. We cannot too strongly urge this point upon public attention.Extract from Dr. Hofmann's and Mr. Witt's report." 22 "We have also obtained from Mr. Etheridge, Naturalist to the Museum of Practical Geology, the results of a microscopical examination of specimens of mud taken from the banks of the Thames. This mud appears to contain about fifteen per cent. of organic matter, 20 per cent. of debris of metropolitan roads, while the remainder is partly alluvial and partly crushed flint and gravel from the basin of the Thames. " From these several considerations we are of opinion that if the sewage were removed from the Thames, the river would be very materially altered in character; but we do not anticipate that it would present the appearance of a clear stream until the projecting headlands at the termination of every reach shall have been protected from the disentegration caused by the agitation of the water, which is principally caused by the steamboats. " Our attention during the last few weeks has been particularly called to the state of the river Thames, the noxious smell from which has assumed a great degree of intensity; but this arises not so much from any unusual accession of foul sewage, as from the diminished volume of the stream at the present season, and from the more rapid decomposition of the organic matter, which has been favored by the very high temperature of the water of the Thames. "The pollution of the river is an evil which has increased, and must continue to increase with the growth of the metropolis.'It will therefore be useful at this part of our report to show what the increase of population has been, and to consider what may in all probability be the future rate of increase." Extract fi'om Copy "of Report, presented to the METROPOLITAN BOARD of WORKS, by Messrs. HAWKSLEY, BIDDER and BAZALGETTE, 1858." London. " Condition of the River. " One great object to be accomplished by a system of main drainage is the purification of the river Thames. It is, under 23 the circumstances of the case, to be regretted that amongst the general public both undue expectations and exaggerated apprehensions have of late been excited as to the condition of the river. Some persons have been led to expect that the Thames will, in the course of a few years, be made a perfectly pellucid stream by the diversion of the' drainage; whilst others have supposed that the Asiatic cholera, and other diseases, are principally attributable to the fouled condition of the river, induced by the sewage which is daily poured into it. "' Misapprehensions such as these cannot be too speedily dispelled. Within the metropolis, the Thames never could have been a I silvery' stream. There can indeed be no doubt that if every particle of sewage were removed from the river, the Thames, as it now exists, with its rapid tide and its enormous traffic, must still remain a muddy water, differing but little in appearance from its present condition. The Referees themselves admit that they do not anticipate that the Thames will present the appearance of a clear stream until the projecting headlands at the termination of every reach shall have been protected from disentegration. " Several causes have contributed to the present condition of the river and its banks: "First. The removal of old London Bridge has greatly augmented the tidal scour.' Second. The improved drainage of the land hasbrought down the upland waters with increased expedition after rainfall; thereby diminishing the quantity of water in the river in hot weather, and adding to the quantity of earthly matters conveyed by the floods. "' Third. The substitution of water-closets for cesspools. "Fourth. The agitation of the water by the action of steamboats, and the augmented velocity of the current induced by the removal of obstacles to the tidal flow. These operate to retain the mud in a state of suspension. "Fifth. The increase of population in and near the metropolis. 24 " Of these, the scour, the floods, and the agitation, are the most influential contributors to the existing appearance of the river, and these will remain in operation and continue to produce like effects after the sewage shall have been withdrawn. We may, therefore, at once state, that the production of a clear or sensibly purified stream, in and near the metropolis, will prove a hopeless task, unless some powerful ruler shall in a future age determine to improve the appearance of the river at the expense of its commerce, by damming back the tide at Greenwich or Woolwich. Were there no population whatever existing on the Thames, the banks of the river, from its mouth to above the western limits of the metropolitan area, would, in the present condition of things, be covered with mud deposits, in consequence of tidal action alone, and the water remain almost as turbid as it is now. " For the proper understanding of the reasons for our final recommendations, it is necessary that we should draw the especial attention of the Board to the results of the investigation we have caused to be instituted by Dr. Letheby, to whom (on account of his eminence in chemistry, his knowledge of medicine, and the personal interest he has taken, as the medical officer of the City of London, in all that concerns the health of the metropolis,) we have thought it right to commit the hygienic portion of our inquiry. We have also considered Dr. Letheby not the less fit to assist us, because he commenced the investigation under the known influence of casually acquired, prepossessions adverse to some of the views to which we had been led by our own observations on tidal rivers, made in many previous years, and in many parts of England and the Continent, as well as upon the river Thames during the period in which its physical condition has become the subject of public complaint. "From the results of our own practice and experience in hydraulic engineering, and particularly in reference to the drainage of towns, and the utilization of the products of sewage, we have long been aware of the important fact 25 that those organic matters which are commonly received from the domestic drains into the street sewers, and are there acted upon by water and air, undergo changes and decompositions not necessarily of a putrefactive character, but in the course of which they either become resolved into their original elements, or become combined into new forms, essentially different from those in which they had originally existed. These changes are effected with great rapidity-so much so, indeed, that it is rare to find in the waters discharged from the sewers of a large town any of those rich, fertilizing agents it has been the object of so many endeavors to obtain-fertilizing agents of a class which, if they could continue to exist and act in combination with flowing water, as they observably exist under other circumstances, would engender nuisances of a character most prejudicial to health and intolerable to the senses. The elements of the organic compounds, which are found in the excreta of towns, are all essentially pure and innocuous. It is only the condition and proportion in which they become united in effete matter, that communicates to such matter its disagreeable, or, it may be, poisonous properties. Sulphuretted hydrogen is a deadly gas, largely evolved from excrementitious matter whilst passing through the process of putrefactive decomposition. But hydrogen, one of the two elements of this deadly gas, constitutes a ninth part by weight of the water we not only drink with impunity, but know to be in a thousand ways essential to animal and vegetable life; whilst sulphur, the other element, is in its natural state a perfectly inert substance, incapable by its presence of producing any injurious effect upon the vital economy. So hydrogen and nitrogen, the latter a gas which constitutes four-fifths of the atmosphere we breathe, and both of them inodorous, combine together to form ammonia, the pungent basis of many of our most valuable manures; and this again in union with sulphuretted hydrogen is a most noisome emanation from the fcecal matter transmitted to the sewers. If the excreta then could continue to exist as such, and could undergo the same process of putrefactive decomposition after 26 being conveyed into the drains, as we know would otherwise result, our sewers and rivers would on the one hand, have long since become cesspools of the most offensive and deadly description, while, on the other hand, the manufacturers of fertilizing compounds would have experienced no difficulty in recovering the rich products of animal existence for which they have hitherto sought in vain. " We feel assured, however, from the facts before us, that so soon as the refuse of life has become thoroughly blended with water, chemical changes of the most important character become gradually effected by the oxygenation (without putrefaction,) of some, if not of all, the combustible elements, and the consequent decomposition and arrangement of the other elements into inorganic forms nowise injurious to the health of animated beings. Hence it is, that the substances which enter into a sewer are either not to be found at its mouth, or are only to be there obtained in a much altered and scarcely recognizable form. And hence, too, it is that the admission of foul organic matters into our streams and rivers fails to render them permanently impure, or sensibly injurious. This beneficent process of Nature is indeed gradual, and, to a certain extent, undoubtedly dependent on the volume and the quality of the water into which the dejecta are received. Observation, however, has satisfied us that when sewage water of ordinary strength becomes intermixed in a flowing stream with ten or twelve times its own volume of fresh, or freshened water, it ceases to have any tendency to run into putrefactive decomposition, and is finally' consumed " by the oxygen with which one or more of its elements enter into purifying combination. "' We have examined the river Mersey, which flows from Manchester, Stockport, Bolton, Bury, Rochdale, Oldham, and numerous other of the important manufacturing and densely populated towns of Lancashire and Cheshire; the river Aire, which flows from Leeds, Bradford, Halifax, Huddersfield, and other towns of the West Yorkshire manufacturing district; the River Don, which flows from the crowded 27 towns of Sheffield and Rotherham, and yet becomes pure enough to be drank at Doncaster; the river Soar, which formerly quitted Leicester of inky blackness, and yet became beautifully pellucid, and full of fish and vegetation before its arrival at Loughborough-and in all these instances, we have remarked with wonder the rapidity of the oxydizing process by which Nature causes the disgusting feculae of towns to become resolved into pure and inoffensive substances. The valuable analytical researches, contributed to the Referees' Report, by Dr. Hofmann and Mr. Witt, afford scientific evidence of the accuracy of the conclusions derived from the study of the phenomena of observation. " At page 8 of their report, the Referees, with another object, compile from the results of Dr. Hofmann and Mr. Witt, the following remarkable table, exhibiting the condition of the river at six places, commencing at Kew Bridge above London and terminating at the Victoria Docks below London. RIVER WATER. Total amount of solid C; c o constituents in O= o. Grains per Gallon. 5 e b e'., Organic........1... 1*844 1*992 2*359 1*937 2*194 2-032 2 059 Mineral...........23067 20 124 23 67223 496 23 676 25*649 23 281 TOTAL........ 24 911 22-116 26-031 25 5433i25870,27*681 25 340 "' Now, from this table, it is manifest that the organic matter nowhere much exceeds 2 grains in a gallon = -5; and that it is of nearly the same amount in all parts of the river between the points named, at London Bridge as at Kew; this amount being in itself very small, and scarcely in excess of the quantity of organic matter to be found in the waters of nearly all tidal rivers, and in many non-tidal rivers, whether flowing from peopled or uninhabited districts. The Referees are themselves much perplexed with the result, and 28 they suggest explanations and inferences which we believe the facts will not sustain. With regard to the equal diffusion of organic matter in all parts of the river, they allege' that it' must be accounted for by the fact that the whole of the sewage which flows into the river at low water, and during the first hours of the flood, is carried up by the tide into the higher parts of the river.' We believe it is not to be thus accounted for; because, independently of the very small amount of organic matter present in any part of the river, it is clear that if the sewage discharge between London and Westminster Bridges, in maximum volume near low water, and into a then minimum volume of river water, were so washed up the river and remained in the water in an undecomposed cbndition, an equal or a nearly equal diffusion would be impossible, and the quantity found in the upper reaches of the river would be excessive. We consider, too, that the conclusions of the Referees are further invalidated by reason of their having omitted to deduct from the total of the organic matter discovered in the water taken from the river in or near London, the quantity brought down by the river from above London, natural to it and inseparable from it. Fortunately, we are not without independent and unexceptionable means of determining the value of this necessary deduction. On the 23d of January, 1851, the then Home Secretary appointed Thomas Graham, Esq., Dr. W. A. Miller, and Dr. A. W. Hofmann, a Commission'On the Chemical Quality of the Supply of Water to the Metropolis.' On the 17th of June following, those eminent gentlemen made their Report, and in that Report they give a minute quantitative analysis of Thames water,' Taken at Thames Ditton,' a place situated a few miles above the tidal influence. In this analysis, the Commissioners state the quantity of organic matter existing in the Thames water at that point to be 2'29 grains in a gallon, or as much as was afterwards found by Dr. llofmann and Mr. Witt in the water taken at London Bridge; whilst the water of the Lambeth Company, then derived from the Thames in London, contained, according to the same series 29 of analysis, only 2'59 grains in a gallon. Again, Dr. Letheby, who has recently made careful analysis of the Thames water under our direction, finds at London Bridge, at high water, only 3 grains in a gallon of organic matter; and at low water only 2'7 grains, of which 1t6 grains are dissolved and 11. grains are suspended. We could multiply examples of this kind to an almost indefinite extent. These important results convince us that the influence of the sewage on the physical and hygienic condition of the Thames, has not only been much mistaken, but that it has also been greatly exaggerated. "' Endeavouring to explain the results of their own chemical inquiries, the Referees proceed to say,'since the quantity of dissolved organic matter is so small, the unwholesome character which it imparts to the water must arise chiefly from the peculiar condition in which it exists in the water.' We regard this style of reasoning as purely hypothetical; for we can find no evidence whatever to support the two assumptions made in this brief paragraph. We have endeavoured to ascertain whether an undue rate of mortality prevails amongst the working people specially occupied upon the river, and we find there does not; there is, therefore, no proof of the unwholesome effects thus suggested to be produced by the state of the water in the river. Low situated, damp, and overcrowded dwellings on the margins of rivers are proverbially unhealthy'in every quarter of the globe; nor is it to be wondered at that the sanitary condition of the population residing at Rotherhithe and the isle of Dogs is not comparable with that of populations residing in more favoured situations; but we assert that the statistical results of mortality and disease, procured through Dr. Letheby, and published in his report, (vide Appendix,) distinctly disprove both the alleged unwholesome character of the emanations from the water of the Thames, (for the water is not drank,) and the existence of the organic matter in that'peculiar condition' on which this hypothesis is founded. It is true some evidence of peculiarity of condition is endeavoured to be inferred from the fact that Thames water, after being re 30 moved from the river, becomes putrescent. But we would observe that the waters of the Thames, as well as those of many other rivers, were notoriously subject to this peculiarity before the sewage of cesspools became introduced into the river. As, however, purification results from the oxygenation of organic matter in a running stream of freshened water, it follows, that experiments of the kind referred to have little more than a precautionary bearing on the subject under discussion. Dr. Taylor, the eminent analytical chemist, in his examination before a Committee of the House of Commons on' The Metropolis Water Supply Bill,' speaking of the effect of water on sewage matter, states:'All such substances are very rapidly decomposed and destroyed; the nitrogen is converted into nitric acid; the sulphur is converted into sulphuric acid; so that those fcetid and putrid substances which go into the Thames from London, when rolled about by the action of the water containing an enormous amount of air, are all oxydized and destroyed; within a certain limit they may be found; but still, after a very short passage they are very soon indeed destroyed.' " I believe it is the opinion of every chemist who has considered the subject, that sewage matter does not remain as sewage matter in well aerated water, but that all phosphorus, sulphur, and nitrogen, are speedily destroyed by the oxygen in that water. Every 1,000 gallons of water will contain 46 gallons of oxygen, and that oxygen destroys all such putrescent effluvia.''' IWith water not exposed to the air, and not containing air, it is most offensive and unwholesome; but with water containing air, like the Thames, and exposing an enormous surface to the air in its daily motion, the effect is completely to obliterate every trace [of sewage matter] that a chemist can detect.' "' In the Thames, and other water, the air is in a state of solution, the matter in a state of diffusion, and thus the air and this fcetid matter are in the very condition to combine together and form an innoxious compound; it requires time 31 and motion, but still it does take place with very extraordinary rapidity.' "'The supposition that the drainage of London, which goes into the river about the bridges, remains the drainage of London all up the river, is contrary to all chemical experience; it is contrary to every chemical fact and every chemical analysis.' "Our object in making these remarks is not, by any means, to assert the absolute purity of the Thames; but we seek to dispel unfounded apprehensions, and thus to induce in the public mind a calm consideration of the whole of the facts from which the ultimate determinations of the Board shall be derived. " We are far from denying that the sewage of large cities may be discharged into'rivers, little if at all adapted, either by art or nature, for its reception; and we believe that the circumstances under which the tide-locked sewage of London is at the present time poured into the Thames, are revolting to the senses, and deleterious to health. For the most part the sewage of London, (pent up during the period when the river is fullest of water, and in only a partially decomposed state,) is discharged when the tide recedes, near to the bridges and piers most frequented by the population. At these and other less observable points, where the river is shallow, and the current slack, deposition accordingly occurs; a filthy mud-bank, consisting partly of alluvial matter, and partly of organic matter, is formed: and in hot weather an effluvium is given off from the putrifying organisms which, there becoming exposed, lie reeking in the sun as the tide continues to descend. " The Referees say, (Report, p. 9):'It would also appear that the black mud from the sewage contains a considerable quantity of organic matter, which is most deleterious; an immense mass of this fcetid mud has accumulated in the bed and on the banks of the river, and it is continually supplying to the water large amounts of soluble matter in a state of putrescence, and contaminating the atmosphere with most 32 offensive emanations. It is probable that the unhealthy condition of many towns on the sea coast is caused by deposits from the sewers of mud of this character.' "And Dr. Hofmann and Mr. Witt, at page 7 of their Report, employ the following forcible expressions:' We cannot but emphatically insist upon it that the formation of this mud deposit in the river, appears to us by far the most serious evil which results from the discharge of the London sewage into the river. We cannot too strongly urge this point upon public attention.' In these conclusions we entirely agree, and, although we are not disposed to think that the whole of this noisome mud results from the deposition of sewage matter, yet we are satisfied not only that a real and increasing evil has its origin in this source, but that this evil has already attained such proportions as to render it essential to the well being of the metropolis that means should be taken for its immediate and permanent abatement. "Much of the mischief would no doubt be removed by the construction of sewers of interception, but this operation alone would not be sufficient for its entire suppression. Any person who examines the state of the Thames, especially within the tidal reaches, whether above or below the metropolis, will be satisfied that the periodical withdrawal of the water of the river from the muddy surface of its bed, is, in the hot weather of summer, invariably succeeded by disagreeable emanations only too plainly indicative of the decomposition of animal and vegetable organisms. " We believe that the only certain remedy for the inconveniences thus referred to will be found, conjointly with the construction of the sewers of interception, in the construction of an embankment on either side of the river, extending ultimately from London Bridge to Chelsea Reach, and of such ample breadth as shall confine the tidal waters within a channel of sufficient depth to insure the covering of the bottom even at low water of greatest springs. We are quite sure that if the river were properly trained between vertical walls the deposition of mud would become nearly impossible, 33 and the scour would become so great as, in a short time to establish a new depth, and a new and improved regime in the navigable channel. It would be foreign to our present duties to do more than to add, that we believe the advantages which would result from the construction of a Thames embankment, would not be confined to the improvement of the sanitary condition of the river, but that on the contrary, it would give relief to the overcrowded thoroughfares, improve the commercial value of the river frontages, afford desirable opportunities for the quiet recreation of the people on Sundays and holidays, and contribute greatly to the architectural embellishment of the metropolis. "In the course of the investigations we have had occasion to make of this subject, we have been brought to the conclusion that many impurities in tidal rivers proceed not from the admixture of sewage with river waters, but from the admixture of sea water with land water. The inhabitants of London are generally impressed with the opinion that the waters of the sea do not ascend within the limits of the metropolis; and the fact would be established if experiments with solid floats were found to represent the paths taken by the particles of a fluid. This, however, is not the case. The tables we publish in our appendix from the medical officers of the "Dreadnought" hospital ship, exhibiting the results of analyses made without any reference to our inquiries, confirmed as they are by the investigations of Dr. Letheby, most distinctly prove-' First. That the matters held in suspension by, and dissolved in the river waters exist in the greatest proportion at high water —that is to say, when the intermixture of sea water with the land water is the greatest. They are then nearly four times as abundant as at low water, when the tide is returning loaded with all the mechanical and chemical impurities discharged from the sewers of London. " Second. That irrespective of temperature at periods after heavy rains, when the river is most largely charged with land waters, combined with waters from the sewers, the proportion of impurity is much diminished. 3 34 "The analyses of Dr. Odling commenced on the 9th of March, 1857, were continued regularly through the spring, summer and autumn months, and terminated on the 23rd of December, 1857. They were made solely in the interests of science, and, being continuous, are more valuable for the purposes of our inquiry, than any Researches made within the briefer period allotted to our investigations. These analyses show that the total amount of salts and organic matters contained in the waters of the Thames, off Greenwich, at high tide, is, on the average, no less than 191'23 grains in a gallon; but that, at low tide, when the sewage of London is passing seaward in greatest quantity, the amount of salts and organic matters is then reduced to 45'91 grains in a gallon. In the former case, the organic matters are 16'28 grains in a gallon; and, in the latter case, only 6'13 grains in a gallon; although the water is, in all probability, still not entirely free from seaborne impurities. "To afford a further test, Dr. Odling was so good as to undertake another series of hourly experiments on the water of the returning neap tide of the tenth March, 1858. At high water the total residue was 58'87 grains, while at low water the total residue was only 27'87 grains; the hourly decline from the maximum to the minimum being extremely regular and consistent. Moreover, at high tide, the total organic matter was 4.69 grains, while at low tide it had become similarly reduced to 2'64 grains. Again, Dr. Letheby's investigations show that, under ordinary circumstances, the sea water penetrates, in small quantity, at least as high as London Bridge. The salts (including a very minute proportion of organic matter) found by Dr. Letheby to exist in a gallon of Thames water, taken at the undermentioned places, were as follows: AT HIGH TIDE. AT LOW TIDE. Grains. Grains. Higham Creek......... 1785X3 1276 5 Tilbury......... 1556 4 1224 9 Greenhithe................... 1444 -3 662 2 Rainham Creek....... 1146-2 646' 0 Barking Point................ 858'5 111' 0 Woolwih.453 6 60 6 London Bridge.............. 26 5 24 9 "The relative amounts of the combined sulphuric acid are even still more indicative of the influence of sea water on the condition of the Thames in and near London-an influence which will clearly not be diminished by the removal of the sewage to a lower point of discharge. " In considering the causes of the turbidity of the Thames, it should be remembered that the amount of solid matter of every description which is poured into the Thames by the London sewers, is a comparatively insignificant quantity, certainly not greater than 250 tons a day, a quantity scarcely exceeding that which is cleared out of the Docks by manual labor only. The mud incident to the Thames as a tidal estuary, is largely in excess of the mud projected into the Thames by any population on its banks; the former is permanent, whilst the latter is perpetually undergoing destructive decomposition. Supposing, however, as an extreme illustration, that the sewage mud is indestructible, and that it takes 50 days to escape to Gravesend, it would there find itself intermixed with a volume of water no less in quantity than 250 millions of tons; so that only one-20,000th part of solid matter (i. e., 12,500 tons in 250,000,000 tons,) would, at the expiration of 50 days, become intermixed with the river water between London Bridge and Gravesend, or (supposing there were neither deposit nor decomposition,) 2 ounces of insoluble matter would remain in a ton of water. Nothing, therefore, can be more erroneous than to suppose that the opacity of the river is an indication either of its 36 unsanitary state, or of a condition produced by the admission of sewage mud. The experiments of Messrs. lofmann and Witt, relied upon by the Referees, demonstrate that the Thames at Kew Bridge contains as much organic matter as the Thames at London Bridge, although every one may observe that the water at Kew is nevertheless much clearer than in London. In many rivers besides the Thames, (the Nile for one example, the Humber for another, and the Elbe for a third,) whilst the opacity is excessive, the chemical purity of the upland water is attested both by experiment and use. "' That the waters in the Thames exercise any decidedly unfavorable influence on the sanitary condition of the metropolis, is a position which the foregoing facts and the valuable papers we publish in our Appendix, effectually refute. It is, therefore, to be regretted that the Referees should have given color to this proposition by the publication of a' Cholera Map,' entitled a' Map showing the Lines of Main Sewers in the Metropolis, and the ratio of the mortality from Cholera in the several districts.' Nothing can be more fallacious than any attempt to indicate the influences of sewage upon cholera. On the showing of the map itself, the sewer running through Gravel Lane, Southwark, divides two districts, one of which was direfully assailed by cholera, whilst the other was comparatively free from it. If there were any coincidence between the state of the sewers and the effects of cholera, it might be supposed that the population on one side of a sewer would have been as much affected as that on the other. So again, as relates to the river, whilst on one side of the Thames, at Bermondsey, the deaths from cholera were as many as 20'1 per thousand of the population, on the shore immediately opposite, at Wapping, there were only 3'3 deaths per thousand; and in the northern water-side district, between Southwark and Blackfriars Bridges, there were only 1'8 deaths per thousand, as against 20.8 deaths per thousand in the district on the opposite bank. Of the two districts, Bermondsey and Wapping, the latter is the more closely 37 built, and is equally below the level of the Thames. And again, while in Deptford the deaths from cholera amounted to 20'6 per thousand, in the Isle of Dogs, immediately opposite, a place most imperfectly drained, and surrounded on three sides by the river, the deaths were only 4'4 per thousand. On a recent occasion, Newcastle-upon-Tyne was severely attacked by cholera, yet Sunderland, in the immediate neighborhood of Newcastle, and in every other respect a similarly circumstanced town, entirely escaped; nevertheless, Sunderland had twice previously suffered from cholera to a fearful extent. Many other instances of the inscrutable character of the cholera attack might be easily adduced.' Suffice it to say, that the presence of Asiatic cholera has been alike used by enthusiasts and by interested parties for the attainment of the most contradictory ends; and therefore it is, we the more regret that the Government Referees should have thought it necessary to call into their assistance the untrustworthy aid of'The Cholera Map.' " To attribute the advent of cholera to any special cause is, in our opinion, unfair, delusive, and, in the present state of our knowledge, utterly unwarranted. Defective drainage may tend to lower the standard of health, so may the peculiar habits of the people, their occupations, the state of ventilation of their dwellings, the condition of the atmosphere they breathe, the food they eat, the character of the water they imbibe, for these have all been regarded at different times and by different persons as indicating the causes of contagious typhoidal cholera; while the Registrar General is, on the " * The singular uncertainty of the choleraic attack is further evidenced by the following instance, exactly the reverse of the case of Sunderland. Two of us are intimately acquainted with the principal towns in and near the Baltic provinces, through which cholera has invariably marched in its route to England; and one of us was at Copenhagen in the year 1853, when that city was, in common with other northern cities, so destructively ravaged by the Asiatic cholera. Copenhagen is an undrained town, situated on the margin, and almost on the level, of a tideless sea. On one side of the inner court of each block of houses is the well, or cistern; on the other side is the cesspool. A large portion of the city is built upon excrementitious refuse; and on an island, separated only by a ditch, is the great deposit of the town ordure. In hot weather an intolerable stench pervades the place, and all the conditions supposed to be favorable to the production of the disease are in fullest activity; yet, in 1832, and again in 1849, when other Baltic towns were severely visited by cholera, Copenhagen entirely escaped." 38 other hand, of opinion that the levels of the inhabited districts have the most material influence upon the epidemic, and has published a singularly curious diagram in support of this view of the subject. To present to Parliament, therefore, a' Cholera Map,' tending to prove that cholera is attributable to the courses of the sewers, or to the relative proximity of the districts affected to the Thames, was, in our opinion, calculated to induce the Legislature to draw an inference notjustified by any reliable facts. "We think, however, that the virulence of the attack, though not the presence, of cholera in Bermondsey and its neighborhood, has been in some measure accounted for by Mr. Donaldson, who, in his evidence (Report, p. 306,) states-That.' there are many places in Bermondsey, Rotherhithe, Deptford and Greenwich, the ground of which is quite honey-combed with cesspools.' If we felt warranted in drawing any inference from the map, and facts before us, we should incline to the opinion, not that the aggravated form of the disease in Bermondsey, and other adjacent places, was attributable to the state of the river, or the courses of the sewers, but to the known and admitted imperfection of the existing drainage. There can, however, be no doubt that, in the long continued hot weather of the summer months, the banks of the river, especially above London Bridge, are offensive, and that, when in this state, they contribute to render the surrounding atmosphere more or less impure. It will, therefore, be our object to apply ourselves to the question, how this evil is to be remedied to the utmost extent, having regard to the reasonable expenditure of money and time in the execution of the works to be undertaken for the purpose, and to the probability of the early construction of a terrace embankment on each side of the river. " Apart also from the question of the clarification of the river, it cannot be denied that good drainage is essential to the general health and comfort of every household, and therefore the present arrangement, which admits of the sewers at the lower levels being frequently inundated from the 39 higher, must necessarily receive consideration, with a view to the application of some sufficient remedial measure.'" We shall, therefore, now direct our attention to the consideration of the means to be adopted for the removal of the matters by which faeculent deposits are occasioned, and for the withdrawal of such reasonable quantities of rainflow as will greatly mitigate the evils of floods." Extract from pp. 8 to 11, of" Copy o.f a letter to the Right Honorable Lord JOHN MANNERS, M. P., First Commissioner," etc., "in answer to the Report made by Mlessrs. Bidder, Hawksley and Bazalgette." London, July 7, 1858. [See preceding extract.] "Effect of the Sewage on the River. " We stated as a conclusion in our report, that the influence of the sewage on the Thames is pernicious. Mlessrs. Bidder, Hawksley and Bazalgette argue that we have greatly exaggerated the causes of the apparent impurity; and the most important part of their report is that devoted to the condition of the river, because, if the arguments they adduce are sound, the Thames must be nearly as pure whilst receiving the sewage as it would be without it; and all that would be required for improving the drainage, would be to protect the low level districts from the upland waters by short intercepting sewers, as proposed by Mr. Rennie, in 1806. "Before proceeding to consider the arguments adduced under this head, we take the opportunity of directing attention to another instance contained in the report, where Messrs. Bidder, Hlawksley and Bazalgette have made an incorrect statement respecting our propositions. "In this case they state that we published a cholera map, to show that the pollution of the Thames is unfavorable to the sanitary condition of the metropolis. That it is unfavorable we entertain little doubt, but the cholera map was given, as we distinctly stated in our report, to show the fact which has long been established by the Registrar General, that the 40 low level districts, viz., those where the existing drainage is imperfect, and the sewage is habitually backed up during a portion of every tide, and the soil constantly saturated with sewage, are the most unhealthy districts in London. Messrs. Bidder, Hawksley and Bazalgette end their argument against our cholera map, by drawing from it the very same deductions which we drew in our report. " The argument adduced by Messrs. Bidder, Hawksley and Bazalgette, that because cholera does not always attack unhealthy localities, therefore it is unwarrantable to consider defective drainage to be one of the causes which especially contribute to it, is one which we are content to leave to be answered by persons of eminence in the medical profession. We may, however, observe, that it would be just as logical to assert that gunpowder is not explosive, because it does not explode unless it be heated. The influence of epidemic merely causes the explosion; but the epidemic influence must be there to do it; and so narrow are the limits of this influence that it will single out particular houses on one side of a street, and leave the other untouched.' With respect to the statement of Messrs. Bidder, Hawksley and Bazalgette,'That the waters in the Thames exercise any decidedly unfavorable influence on the sanitary condition of the metropolis, is a position which the foregoing facts and the valuable papers we publish in our Appendix, effectually refute,? it would appear, from a letter which we have lately received, and which we have appended, that the Registrar General considers that the comparative insalubrity of the low level districts of London is, to some extent, due to the present state of the Thames. The following is a quotation from this letter:'Perhaps an arrangement of the facts, according to the elevation of the districts, would serve to illustrate the effects of the present state of the Thames on the mortuary returns, quite as well as any other, since the arrangement with reference to proximity to the river is necessarily imperfect, and the emanations from the river extend, like the fogs, all over the London area.' 41 "The following extract from the Registrar General's weekly report, dated 21st June, 1858, bears upon Dr. Letheby's statement that it does not appear that the emanations from the Thames have the least effect upon the patients of the Dreadnought Hospital Ship, viz.:'The medical officer of the Dreadnought Hospital Ship appends the following note to his report:'The water of the Thames stinks most abominably; I cannot but think that the foul air has a deleterious effect generally on the health of the patients of this hospital, and I know that it has had something to do with the induction of fever in two instances, on the orlop deck, the ports of which are only a few feet from the surface of the water. Several men on board, myself among the number, have suffered slightly from diarrhoea." And the accompanying table, obtained from Mr. M'William's valuable report, shows the greater average annual mortality in the ten years from 1847 to 1856, of the Water Guard, (who are employed on the Thames,) as compared with the water-side officers of Her Majesty's Customs.* AVERAGE ANNUAL MORTALITY PER CENT. Ages. 20 - 30 *924 136 30 - 40 1 -115 * 872 40-50 1-837 1 349 _50 — 60 7-143 2 041' With regard to the pollution of the Thames, Messrs. Bidder, Hawksley and Bazalgette advance certain propositions, to which it is desirable that attention should be directed. " Mr. William M. Ord, Surgical Registrar at St. Thomas's Hospital, states, in a letter to the Times, on the 6th July, that' personal questioning of nearly two hundred men, constantly working on the river, showed that symptoms of poisoning, as well marked in their way as diarrhcea, are produced by the foul exhalations' of the Thames." 42 "In the first place they are of opinion, that were there no population existing on the Thamnies, the banks of the river,. from its mouth to above the western limits of the metropolitan area, would, in the present condition of things, be covered with mud deposits, in consequence of tidal action alone, and the water remain about as turbid as it does now. To apply the term'turbid' to describe the state of the Thames water, is a mistake. The water is dark, and of a peculiar color, like the water of a sewer. Where population has spread along the sides of the river, the mud banks have been protected from disintegration by the owners of the property; and hence the'turbidity' of the water from this cause within the limits of the metropolis is necessarily much lessened by the existence of the population. "The Thames might still, to some extent, continue to be muddy, even if the sewage did not flow into it; but though muddy, it would not evolve disagreeable effluvia. It is not the existence of mud, but it is the putrescible character of the mud in the river, arising from the presence of sewage, which renders it offensive. How far the effluvia disengaged are injurious to health, is a medical question; most assuredly they are offensive, as any person who travels on the river can bear witness to from experience. No one would expect that the diversion of the sewage would render the river quite pellucid, but that it must be less impure if the refuse of 3,000,000 people ceased to be poured into it, is self-evident. "In the next place they state, that the organic matter received into sewers, undergoes changes and decompositions, not necessarily of a putrefactive character, with such rapidity, that it is rare to find in the waters dischargedfrom sewers of a large town, any of those rich fertilizing agents it has been the object of so many endeavours to obtain. "Undoubtedly considerable changes are effected in sewage by oxydation, putrefaction and dilution with water, before it reaches the mouths of the sewers; but it is altogether untrue' that it is rare to find in the waters discharged from sewers any fertilizing constituents,' for Dr. Hofmann and Mr. Witt 43 show that one gallon of sewage contains 30 7 grains of organic matter and 71 of mineral salts, containing 6' 7 grains of nitrogen, and 1 85 of phosphoric acid. The sewage contains in the aggregate an enormous quantity of valuable fertilizing matter, but diluted with so large a volume of water that its extraction by chemical means would not prove remunerative. That this matter is offensive, any one may learn by standing a few minutes over the mouth of one of the sewers. " We do not see the force of the remarks made by the Board's engineers, that the elements of the organic compounds which are found in the excreta of towns are all essentially pure and innocuous, since most of the poisonous compounds of organic chemistry contain harmless elements; thus, nitric acid, the most corrosive poison, contains the same elements as the atmosphere. "That sewage matter is a highly putrescible body is clearly shown by Dr. lHofmann and Mr. Witt's report, and the decomposition to which it is necessarily subject evolves these elements, harmless in themselves, in certain combinations which are deleterious; and in considering the sanitary question, we are concerned with the gases and with the organic matters dissolved and carried into the atmosphere, both by the gases and by the evaporated water, which is loaded with the foul emanations, and not with the elements of the gases, or with the state in which these elements existed in the sewage itself. " They further observe, Thlat as soon as the refuse of life has become thoroughly blended with water, chemical changes of the most important character become gradually effected by the oxygenation (without putrefaction) of some, if not all, the combustible elements, and the consequent decomposition and arrangement of the other elements into organic forms nowise injurious to the health of animated beings. " The evidence that the organic matter from sewage still exists unoxydized in the river, is proved by its putrefaction in hot weather, and by the quantity which still exists in the 44 insoluble form, and which would have become soluble if the oxydization had been complete. Messrs. Bidder, Hawksley and Bazalgette argue, that the admission of foul organic matter into rivers fails to render them permanently impure; but this argument is entirely irrelevant to the question under discussion, and so are the inferences sought to be conveyed by the statements made by them, that the Don, which receives the sewage of Sheffield and Rotherham, is pure at Doncaster, which is situate more than 20 miles below the former and 15 miles below the latter by the river. They also instance the Soar as having become purified from the sewage of Leicester by the time it reached Loughborough, a distance of 14 miles. We know that the effects of the Leicester sewage, although not felt at Loughborough, were perceptible at Barrow, which is 101 miles below Leicester; but at this point the river receives a considerable accession of fresh water.'" We might have instanced the case of the river Schuylkill, in Pennsylvania, which receives the refuse of large manufacturing districts, but which becomes purified in a course of 30 miles over beds of limestone, and supplies Philadelphia with pure water. But these cases are not in point, because these rivers flow always in one direction. The Thames would not be offensive to Londoners if the water, saturated with decomposing ingredients, were not moved backwards and forwards through the midst of the population by the tide, and continually agitated by steamboats. If there were no tide, all the refuse would be carried away to decompose lower down. In the next place they argue, That the quantity of organic matter in solution, in the water of the Thames in London, does not much exceed the quantity found in the Thames at Kingston; that, therefore, the influence of the sewage on the physical and hygienic character of the Thames has not only been much mistaken, but that it is also considerably exaggerated. " We showed that although the quantity of organic matter was small, that its deleterious effects were due to its highly putrescible character. 45 "The *presence of sewage matter is strikingly shown by the fact that the proportion of the organic to the mineral matter in suspension decreases on each side of the centre of London, viz., from 27 per cent. at London Bridge to 17 per cent. at Kew and at Rainham.' But it is not the mere quantity of organic matter which proves the presence of sewage in the river; the true test is the quantity of nitrogen and phosphoric acid in this organic matter, which is found to be nearly uniformly distributed throughout the water from Kew to Greenwich. "' It -may also be observed that sewage would communicate, not only common salt to water, but also sulphates. Consequently, the sewage would itself produce water having a composition to a certain extent resembling sea water. "After citing Dr. Taylor's evidence, given before the Committee on the Metropolis Water Bill, in 1851, in favor of the Thames below Teddington being continued as a source of water supply, in order to prove that the foetid and putrid substances which flow into the Thames from London are, after a short passage, entirely destroyed, the Board's engineers proceed to state, that although they are not disposed to think that the whole of the noisome mud deposits in the Thames in London results from the deposition of sewage matter, yet they are satisfied that not only a real and increasing evil has its origin in this source, but that this evil has already attained such proportions as to render it essential to the wellbeing of the metropolis that means should be taken for its immediate and permanent abatement. " In order to remove the mud, they suggest the construction of terrace embankments on both sides of the Thames, in addition to the interception of the sewage, and its removal to and discharge in the river a short distance below London. Many persons entertain the opinion that the embankment of the Thames is a measure which would prevent the noisome effects now experienced from the London sewage being delivered into the stream. We believe the embankment of the Thames would prove most beneficial in removing the mud 46 banks, and preventing objectionable accumulations on the foreshores; but where the quantity of sewage is so large in comparison with the normal downflow of the river, it will not, in our opinion, be sufficient to trust to the embankments only. If the sewage were not allowed to be deposited on the foreshores, it would be held in suspension, and would be more rapidly decomposed, and therefore more likely to disengage offensive and deleterious effluvia; in fact, at the present time the stench is worst at high water. "In the case of the Clyde at Glasgow, the river has been embanked, and yet it is nearly if not quite as bad as the Thames during the summer and autumnal months. " There are many sources of pollution of the river Thames which seem to us immediately preventible. In our report of 31st July, 1857, we enumerated these sources of pollution, and we take the liberty on this occasion of'directing serious attention to them.`" Extract from Report of the effect of Sewage Contamination upon the River Thames, by Dr. Wn. ODLING, Officer of Health for Lambeth. 1858. "Function of Rivers.-From a consideration of the mode in which our rivers are originally constituted, and their supplies of water unceasingly maintained, it is evident that every great river must form the natural drain- of some extensive area. Evaporation is constantly taking place from " * Pollution of the River Thames.-In addition to the flow from the sewers into the Thames, there are other serious sources of pollution which were brought to our notice in our visits to the outfalls of the sewers, and to which it is necessary to direct attention. At almost all the wharves and manufacturing premises on the banks of the Thames, great nuisances arise from the privies, urinals, foul drains, etc., which communicate directly with the river. At the dung wharves and other places, large quantities of objectionable matter are frequently left on the foreshores to be washed away by the tide. "A similar extent of pollution prevails in the docks, canals and inlets which communicate with the Thames. We have also witnessed, on several occasions, most objectionable foul matter being thrown into the river from barges in various parts; and, from observations of the state of the water, our decided conviction is that large quantities of foul and polluted water and other liquids are occasionally let off from chemical works, gas works, and many other manufactories, not only directly into the river, but into many of the sewers and watercourses which drain into it. These practices are of common occurrence, notwithstanding the efforts of the conservators of the Thames to prevent them." 47 every surface of water which this earth presents. This evaporated water remains partly dissolved in the atmosphere, partly deposited in the form of clouds, from which clouds and atmospheric moisture our rain-fall and dew-fall are derived. The rain-fall of the hilly districts ever seeking a lower lewel, ever receiving accessions from the rain-fall of lower regions, washes over and through the soil, delving for itself minute channels which unite with one another to form larger channels. Then springs, brooks, streams, and tributary rivers succeed one another, until in the valley of the district there is formed a huge river, which returns the rain water to its original source, the sea. Thus, from the sea, into the air, over the earth, and back again to the sea, do we find water ever journeying in its prescribed circle. Now the rainXfall is the great public scavenger. First it cleanses the atmosphere, washing from it many impurities, particularly certain nitrogen compounds, such as ammonia and nitric acid, which result from the decomposition of organic matter. Then it purifies the earth, scouring from its surface, and dissolving from its substance, refuse of every description. Hence we find that the purest river water differs from rain water by the substances it has derived from the soil, while rain water differs fiom evaporated water by the substances it has derived from the air. Moreover, we find the water of every river has its own specific character, dependent upon the nature of the district from which it has drained. In common with most large rivers, the Thames is well supplied with variously sized tributaries which empty themselves at different points of its course, from its origin as a distinct river, down to its efflux in the sea. Such, for instance, are the Wandle, the Effra, the Fleet, the Ravensbourne, etc. " Most of our existing main sewers were originally the natural tributaries of the Thames, each carrying into the main river the drainage from its own locality. At one time the minor streams and the main river, though constituted almost entirely of drainage, did not become offensive. All were fulfilling their natural functions, all were exercising effi 48 ciently their self-purifying powers. But in course of time, through an increasing density of population, and a consequent disuse of cesspools, the smaller tributaries were no longer capable of maintaining themselves in a wholesome state. The purifying powers which enabled them to withstand the influx of a certain amount of impurity were insufficient to destroy the daily increasing mass of human excreta which mingled with their streams. Hence it became necessary successively to cover in many of these tributaries, to convert them into actual sewers, and to prevent as much as possible the escape of any emanations from them. In these tributaries, the quantity of substance to be purified was certainly disproportionate to their purifying powers. Now, we have to inquire whether or not the same relation prevails in the main river, whether its self-purifying powers are sufficient for the purification it is called upon to perform. "Nature of Putrefaction.-We know that the excreta of animals, the bodies of animals, the tissues of vegetables, and all forms of organic matter that are not in a living state, undergo decomposition. This decomposition may proceed slowly and inoffensively, as is the case with woody fibre; or rapidly and offensively, as is the case with most animal tissues; but the decomposition of both animal and vegetable matters is effected by the same means. The changes are in each instance due to the presence of air or oxygen which breaks up the organic matter, unites with certain of its constituents, and ultimately converts them into various simple forms of mineral matter. Now, in this process of the conversion of organic into mineral matter, there is one stage, usually known as the putrefactive stage, in which, and in which alone, does the organic matter become obnoxious. The fresh organic matter, living or dead, and the fully oxydized matter, are alike unobjectionable. Putrefaction occurs only at the intermediate stage of partial oxydation. We know that without air or oxygen, decomposition cannot take place at all. Hermetically sealed canisters of provisions are 49 transported from one part of the world to another, and after the lapse of many years, remain perfectly sweet and wholesome, provided the absence of air has been absolutely maintained. With an inadequate supply of air we have the phenomena of putrefaction. The tissues break up into imperfectly oxidized substances which are more or less offensive according to the nature of the tissue from which they were derived. But in the presence of a large excess of air, more particularly of the air contained in earth and water, these imperfectly oxidized and offensive products become. completely oxidized and inoffensive. When animal matter decomposes in contact with a sufficient amount of fully oxidized earth or water, the formation and destruction of the offensive products are almost simultaneous. " The organic matter, both of sewer water and of Thames water, may be classified under the following heads: First we have living animal and vegetable organisms of various kinds; then we have dead organic matter in a sufficiently undecomposed state to serve as food for animalculae; then we have organic matter which is in a semi-oxidized and putrefactive condition, and which cannot furnish food for animalculae, but must undergo a further oxidation; and lastly, we have organic matter that has been so thoroughly oxidized as to be innoxious. Hitherto, it has been nearly always assumed that the organic matter of the river, and of water generally, was all of it objectionable, and that the quantity of organic matter in the water was a criterion of its offensiveness. My own experiments have tended largely to show the incorrectness of this assumption. We know that animal life cannot be supported without organic matter; and sea-water, which is so fertile in animal life, I have found to contain habitually a greater amount of organic matter than exists in river water. Moreover, the water of the Thames at high tide'almost invariably contains a larger proportion of organic matter than it does at low tide, which excess is doubtless in part due to contamination with sea water. Again, in the middle of July last, the waters of the 4 50 London and St. Katherine's Docks, though in a most offensive condition, contained respectively but six and nine grains of dissolved organic matter in a gallon; while several of our Lambeth shallow well waters, that were unexceptionable as to taste, smell and appearance, yielded me twelve, nineteen and twenty-five grains of dissolved organic matter per gallon. Organic matter of itself is not injurious, but under certain conditions it is liable to acquire noxious properties. Under these conditions, sea water, river water, and indeed most kinds of natural water, alike become offensive.* The principal agencies by which the putrefaction of sewage water in the Thames is prevented, are four in number. First, the development of animal life. Second, oxidation. Third, dilution. Fourth, removal by the down scour. "Vital Development. —The generation of countless forms of animal life, the preying of animals upon animals, is perhaps the greatest and most efficient check upon the process of putrefaction. In nearly every class of animals, from the mammalia downwards, do we find beings whose special work it is to act as scavengers, to thrive upon the semi-putrid carcasses and exuvike which are rejected by more cleanly feeders. But in the lower ranks of animals this function is carried on to its greatest extent. Revelling in the midst of putrefaction, " x Referring to the reasons why the sea does not putrefy, Dr. Barnes writes:' whilst it is subject to tidal motion, to agitation by the wind, to the free absorption of oxygen favoured by motion, the organic matter it contains does not putrefy, whatever the temperature, but is converted into multitudinous living animal and vegetable forms. Precisely the same conditions affect the body of the waters in the Thames, both flood and ebb. Thames water, high or low, never fails to exhibit abundant evidence of the rapid conversion of dissolved organic matter into living forms. So long as the water is subject, like the sea, to rapid motion by tides, winds, and other influences, I assert from repeated and positive observation that it does not putrefy. The constant presence of certain living and growing animals and plants in Thames water is conclusive proof against putrefaction. The process of putrefaction is attended by the evolution of gases that are instantly fatal to the living organisms found in it. The fact, however, is that Thames water, high or low, may, and does, become putrid and pernicious under certain conditions. Under these conditions, namely, stagnation, exposure to air, and increased temperature, sea water itself is not exempt from the change. There are salt marshes, perfectly uncontaminated by sewage, more deadly by far than the Thames is assumed to be. In these, putrefaction and other pernicious changes take place, precisely as they do on the mud banks of the Thames, where acres of deposit largely mixed with organic matter are exposed at low water to the air. This is one source of the foulness of the river. It is not the flowing waters, but the exposed stagnant mud.'" 51 thriving in the sewers, and fattening in the charnel houses, do we find animal life in endless profusion and variety. These animalculae, however, do not develop themselves from out those portions of organic matter that are already semioxidized or decomposed, but in the midst of decomposition, they build up their organisms out of the non-decomposed portions, which they, as it were, rescue from putrefaction. Then, in other conditions or localities, they form the prey of animals of a different grade, which could not have resisted the foul atmosphere in which the original stercorine and carrion forms were generated. We are unable to form any conception of the amount of putrefaction prevented by this wonderful provision of nature in its almost unheeded supply of scavenger animals. It must be remembered that animals of every grade, no matter how-much-soever they grow or multiply, do not add one iota to the existing quantity of organic matter. It is the peculiar function of the vegetable to convert mineral into organic matter. Animals live entirely upon the organic matter directly or indirectly built up by vegetables. Throughout their lives they are constantly consuming more organic matter than they yield, which excess of organic matter they convert into mineral matter by oxidation; and at their deaths, they must either furnish food for other animals, or else undergo a more violent continuance of the oxidation to which they were subjected during their lives, and become entirely converted into innocuous mineral matter. cc Oxidation.-We have just observed that organic matter when it has undergone a certain amount of decomposition, can no longer act as a pabulum for animal existences, but to become innoxious must undergo a further oxidation, and be resolved into simpler products. Now, water has the property of absorbing air or oxygen, and this oxygen has the property of destroying putrid compounds. If water, from which air has been removed, be charged with that foul vapor called hydrosulphate of ammonia, perhaps the most offensive of all putrefactive products, that water will remain stinking for 52 months, if the access of air be prevented. But if this same stinking water be exposed to the air, it will dissolve the oxygen of the air, and this oxygen will immediately act upon the putrid matter. Then more oxygen will be absorbed, more putrid matter destroyed, and in twenty-four hours the smell be entirely removed.* It is true that water can take up but a very small quantity of this purifying gas. One hundred gallons of water can only dissolve about three and a half gallons of oxygen, but as fast as the oxygen is consumed, more is absorbed from the inexhaustible reservoir of atmosphere, so that the river may be continuously maintained in an efficient state of oxidation. Moreover, its agitation by winds, tides and traffic, tends materially to keep it in a fully oxidized condition. As a proof of the oxidizing powers of the river, I may state that it always contains nitrates, the most highly oxidized and least objectionable products of the decomposition of animal matter. Moreover, I have never been able to detect sulphuretted hydrogen in Thames water, though were it not for the fully oxidized state of the river, this offensive compound would doubtless be given off in considerable quantity. " Dilution.-This is a very important means for neutralizing toxic agencies of every description. We know that the purest atmosphere of the downs, or of the ocean, always contains that deadly poison, carbonic acid. But the effects of this poison depend upon its state of concentration. When diluted to a certain extent, its deleterious qualities are not simply diluted in the same proportion, but are absolutely destroyed. An atmosphere containing five per cent. of carbonic acid cannot be breathed with impunity. But such an atmosphere, diluted with a hundred times its volume of chemically purified air, would constitute the purest air that exists in nature. In the same way with poisonous emanations of all kinds. Dilution of substance implies more than dilution of effect-it implies annihilation of effect. It is somewhat * I do not find this experiment anywhere, but it is one that I have frequently performed. 53 difficult to ascertain the amount of dilution which the excreta of London undergo in the sewers and river. We can, however, easily approximate to the average minimum of dilution in the sewers. By a return made to the House of Commons, in July, 1854, it appeared that the London Water Companies, taken as a whole, supplied daily twenty-five gallons of water per individual. Now, from a very extensive series of data, elaborated with great care by Messrs. Lawes and Gilbert, it appears that the solid and liquid excrements voided daily by every individual, contain, on the average, only two ounces of dried substance, of which one-half ounce is constituted of mineral matter. Whence, it follows, that if sewer water were of uniform composition, and were derived solely from the water supply and human excreta, it would contain only twenty-six grains of organic matter in a gallon.* " From analyses made by different chemists, we learn that the composition of sewage varies greatly. Sewage from the Earl sewer yielded Messrs. llofmann and Witt only 2' 7 grains of organic matter per gallon. Mr. Way found in the sewage of Barrett's court, 301' 8 grains per gallon. I have found in the sewage from Savoy street, 45' 7 grains; in that from the York road, Lambeth, 48' 9 grains, and in that fron Broad street, Lambeth, 77'4 grains of organic matter per gallon. Messrs. Hofmann and Witt, in their report to the Government referees, on the main drainage question, adopted thirty grains per gallon, as the average quantity of organic matter contained in London sewage, and their estimate is probably very close to the truth. Now, Mr. Bazalgette calculates'that the proportion of the sewage at the present time discharged into the river at our very doors, is, as compared with the water of the Thames, at the period of its discharge, as one to fifty.' So that at present, when the " X The problem for those who advocate, on commercial grounds, the production of solid manure from sewage, is to extract the two ounces of excrement from the twenty-five gallons of water at a profit. I will not say the feat is impossible, though at present we have scarcely any foreshadowings of its realization. But the deodorization of sewage at a certain moderate outlay, is a sanitary problem that has already received a practical solution; and in many parts of the Kingdom, this operation will probably be resorted to with advantage." 54 river contains almost its minimum of water, and receives its maximum of sewage, that sewage increases the amount of organic matter in the river, only to the extent of one half grain in a gallon, a quantity that is absolutely ridiculous. This statement, however, applies only to the average result. At some periods, the effect of sewage contamination is much less; at some periods much greater, than that above indicated. My experiments extending over a period of nearly ten months, show that Thames water, at Greenwich, at low tide, when the amount of sewage poured into it is greatest, and the total volume of water least, contains, on the average, 4 63 grains of organic matter per gallon. The greatest quantity occurred on June 29th, when it amounted to 11i 2 grains, and the smallest on November 23rd, when it amounted to only 2 1 grains per gallon. However, a large proportion of the organic matter contained in the river, even at low water, is derived, not directly from the sewage at that time discharging into it, but from impurities introduced by the previous upcast flow.' Removal by the Down Scour.-In reference to the removal of insoluble sewage from the river, by means of the ebb tide and freshet, it seems that at high tide the water is nearly stationary, and that during this period a considerable deposition of organic and mineral mud takes place. Very soon, however, the force of the downcast in the middle of the stream becomes sufficient to wash away all deposit, and prevent any further deposition; but in the slack, eddies and retrogrades, the deposition is continued so long as the banks are covered by water. I have found the average quantity of suspended organic matter contained in low water, at Greenwich, to be 1' 3 grains, and in high water to be about two-thirds of that quantity, or 0 89 grains in a gallon. If, however, we take into consideration the greatly increased quantity of water in the river at high tide, it is evident that the total amount of suspended matter in the river, even at Greenwich, is greater at high than at low water; and doubt *55 less the excess is more marked further up in the stream. I am inclined to think, with Mr. Goldsworthy Gurney, that suspended'sewage, if thrown into the Thames, no matter how far down, will be brought up again by the upeast; and, if the retrogrades be not destroyed, it will be retained in the river.' But the causes which prevent the suspended sewage being carried away by the freshet, do not interfere with the efficient disposal of the soluble sewage. The greater part of this sewage, flowing into the river at ebb tide, is even now, by the force of the freshet and ebb, eventually carried away into the German ocean. The quantity of dissolved organic matter in the river does not undergo a continuous increase. Its amount seems to be regulated chiefly by the season; which, of course, has a direct influence upon the quantity of freshet, and the force of the down scour. In the summer the amount of dissolved organic matter increases very considerably, while the force of the scour greatly decreases; but in winter the quantity of organic matter becomes so reduced by the increased scour, that its amount per gallon, at Greenwich, very slightly exceeds its amount per gallon at Ditton. Hence, it seems, that in the summer season, it would prove advisable to increase the down scour artificially, by flushing, as first suggested, I believe, by Mr. Freebody. The following analyses illustrate, among other points, the extent to which the river can discharge its dissolved organic matter: LOW WATER AT GREENWICH. Dissolved Organic Dissolved Mineral Rain-fall of previDATE, 1857. HOUR. I matter, in grains matter, in grains ous week, in inper gallon. per gallon. ches. Oct. 22nd. 1A.M..1 2 96 32 91 0 19 " 27th... 1.30.M.. 5 01 14'01 2 85 Nov. 4th.... 10.30A.M. 277 23 28 0 06 "The total rainfall between October 7th and October 22nd, amounted to less than half an inch. On October 22nd there occurred an enormous rainfall, amounting to 2 57 56 inches, or one-tenth part of the average annual rain-fall. Mr. Glashier calculated that on that day twenty million tons, or eighty-four million hogsheads of water fell on the London districts. On October 27th, after the lapse of four and a half days, I found that the amount of saline or mineral matter per gallon, in the low water of the river at Greenwich, had been decreased to one-half the previous quantity, in consequence of the great dilution effected by the rainfall; but that, despite this enormous dilution, the amount of organic matter per gallon, had been nearly doubled, probably from the complete scouring of the sewers, inasmuch as this increase of organic matter was not evidenced in water taken high up in the river. But on the morning of November 4th, I found that this excess of organic matter had been got rid of, and that the water had resumed its usual character. Having thus considered the means now in existence for maintaining the purity of the Thames, we come to the question, Are they or are they not sufficient for the purpose? We have, I believe, no other alleged evidence of the putridity of the river than its constant foul appearance, and its occasional objectionable smell, to which points we will now direct our attention. " Foul Appearance.-The muddy look of the Thames has usually been considered dependent upon the sewage poured into it, and this error was largely propagated by the loose -interpretation of certain paragraphs in a letter which Mr. Faraday published in the Times newspaper some two years ago. All chemists and engineers, however, who have examined the matter thoroughly, are now satisfied that the discharge of sewage has very little direct influence upon the muddy aspect of the river. My own experiments show that this appearance most certainly does not depend upon the organic matter of sewage, but upon clay and other suspended mineral matter. The excess of suspended mineral matter over the suspended organic matter is greatest at low water, when the river receives its maximum of sewage. The min 57 eral mud suspended in the river at low water, forms seveneighths of the whole, and the one-eighth of organic matter is constituted for the most part of living organisms. Suspended matter, or mud, exists to an equal extent in rivers where the contamination with sewage is infinitesimal as compared with the Thames. Moreover, I have reason to believe that the presence of mineral mud promotes considerably the perfect oxidation of the water. " Offensive Smell. —As regards the smell of the river, I believe, from personal examination, and from inquiries of watermen and others, that an offensively smelling condition of the water of the Thames is an exceptional occurrence. Sometimes there is perceptible on the river a smell arising solely from a local cause, as when undiluted sewage from some proximate sewer mouth runs for a considerable distance over the exposed river bank. An offensive smell not unfrequently proceeds from the mud banks, and particularly from that bank which receives the direct rays of the sun. But the most potent cause of smell arises from'the upcast flow disturbing the foul organic mud, which the sun had previously acted upon. At those periods in the summer when the river water itself has an objectionable smell, the smell at high water, or rather at the flow of the tide, is much worse than at low water, when we have the dilution of the freshet stream. I believe, moreover, that all water, when existing in large quantity and in a heated state, has a certain characteristic smell. Even the beautifully pure water supplied by the Lambeth Company from Thames Ditton, smells perceptibly at a blood heat; and the water of the Crystal Palace fountains were said to be actually offensive during the hot weather. In reference to the smell of the river during the summer drought, Messrs. Simpson, Galton and Blackwell write: —' Our attention, during the last few weeks, has been particularly called to the state of the river Thames, the noxious smell from which has assumed a great degree of intensity; but this arises not so much from any unusual ac cession of foul sewage, as from the diminished volume of the stream at the present season, and from the more rapid decomposition of the organic matter, which has been favored by the very high temperature of the water of the Thames.' During this period, every upcast tide dissolved semi-decomposed organic matter from the mud banks, and the downcast tide was insufficient to carry it away. The proportion per gallon of organic matter in the river water, both ebb and flow, underwent a great increase, owing to the inefficient down scour. Moreover, the river was largely contaminated with sea water, and there is reason to believe that the presence of putrefying or putrefiable organic matter in sea water is more objectionable even than in river water. The desirability of artificially increasing the scour of the Thames during the summer drought has been before alluded to. Effect of River Emanations upon Health.-The alleged unsanitary influences of emanations from the Thames are, I conceive, of a very questionable nature, and, at any rate, are not proved by evidence. The high mortality of certain metropolitan districts is not directly proportionate to their facilities for drainage. Thus, Westminster, with a mean elevation of 3 feet, and the Strand, with a mean elevation of 50 feet, are both river-side districts. In the year 1856, the mean death rate of Westminster was 1 in 42'8, that of the metropolis 1 in 45'8, and that of the Strand 1 in 51'2. In the lowness of its death rate, the Strand ranks sixth among the metropolitan districts, despite its dense population. During the last three or four years, the amount of sewage poured into the Thames has increased in an enormous proportion. Therefore, if the fouling of the river does exert any effect upon the public health, this increase of its foulness ought to produce an appreciable effect. On the contrary, we find the death rate and prevalence of epidemic disease in the metropolis to have undergone a marked diminution. Dr. McWilliam, the accomplished physician to the Custom House, who has the charge of about 800 men, whose general health 59 is found to be excellent, despite their regular employment on the river, their night duty on the river, and their great hardships, writes me word:-' I have no evidence that the health of tide-waiters is interfered with by emanations from Thames water; I have certainly heard tide-waiters and watermen complain of the bad smell of the docks and river during hot weather, but I am not prepared to say that I have traced disease of any kind to the odor from the water in either place.' We have the opinions of Mr. Busk and Dr. Barnes, the senior surgeon and physician, respectively, to the Dreadnought hospital ship. They say that the health of the resident staff is excellent, and that the operation and fever cases, two great tests of salubrity, do remarkably well. Dr. Barnes writes me word'- Medical observation of the health of those who live upon the Thames, shows the absence of those diseases which usually denote malaria. Fever is a rare event to originate on the river. Of more than 60 cases admitted on board the Dreadnought during last year, not one could be traced as due to river emanations. They all come from the docks, or from unhealthy ships coming up the river. I have in vain made inquiries to ascertain what disease or form of disease it is that the Thames produces.'" A comparison of the foregoing extracts, though perplexing to those who may wish to get at the exact truth, will show that Chicago, in one respect, has greatly the advantage of London, inasmuch as there are no mud banks along the river here to be alternately covered with water and exposed to the sun or wind by every tide. Instead of stirring up mud deposits, as the steamboats do there, the propellers here seldom do more than violently agitate the surface of the water, which series to aerate, and thus purify it much more rapidly than would otherwise be done. 60 The general character of these extracts, viewed in connection with the local circumstances of Chicago, already mentioned, justifies the conclusion arrived at in this communication-that it is not advisable, at present, to take any steps towards constructing the proposed canal for driving water from the lake into the river, but to wait till further experience shall, if ever, show the necessity of such a measure. So much of the foregoing Report as relates to the Illinois and Michigan Canal has been shown to Mr. Ogden, the former President of your Board. Mr. Ogden's views in favor of the enlargement of this Canal are so well known in this community, that no repetition of them is needed here. In a letter with which he kindly favored me, the whole of which was evidently not intended for publication, he says: " I have read over your Report, and approve the views you have taken generally. The first effort should undoubtedly be the bettering of the channel of the Illinois River, without lockage. The present locks of the Canal are large enough, while the river is in its present condition, unless more than doubled in width, and greatly increased in length, to admit of large tonnage with light draught, better suited to the present River navigation, and this is hardly to be looked for at present. "A channel, in future, 6 feet deep and 200 feet or more in width, connecting Lake Michigan with the Illinois River, would seem to me all that can be hoped for-12 feet would add nothing essential. A point of transfer must exist at Chicago or Lasalle, or intermediate, and Chicago is undoubtedly the most desirable point for it, independently of the saving of the extra cost of a 12 feet instead of a 6 feet channel." 61 As Engineer of your Board, I have felt bound to look at this question simply as it bears upon the sanitary interests of the city; but when two gentlemen so familiar with the subject in its various bearings as Messrs. Ogden and Gooding, the one more particularly as it regards the interests of Chicago, and the other as'to the actual working of the Canal, it is very evident that their views, coinciding so nearly as they do relative to the first steps that should be taken towards the enlargement of the Canal, should have great weight with the public mind. Respectfully submitted, E. S. CHESBROUGH.