Dr. GLOVER said, that time did not admit of his speaking at any length on the subject, but he believed that deodorising processes might be carried out with success, and that the fact of several very impure waters being purified by filtration, was a proof of it. The great object should be to employ materials which were themselves excellent as articles of manure, and which, by absorbing the sewage, would become still more so. Dr. Glover referred to the experiment of M. Chevalier on animal charcoal as a deodorising agent, and stated that he himself had experimented on soot, and found it a powerful deodorising agent. He also referred to the action of sulphate of lime as a fixer of ammonia, and in conclusion stated that he believed the problem, though difficult of solution, was by no means impracticable. large quantities, he had found his cattle feeding upon the That was, however, objected to by Mr. Cooke, on the pasture so treated within twenty-four hours after the score of expense. In 1849, a patent was obtained for application, and forty-eight hours after, no smell what-peat charcoal; it had been extensively employed, and ever was emitted. Again, with respect to liquid manure was sold in Ireland at 1s. per bushel. This might be not being good for other crops than those of grass, he had thought a high price for agricultural purposes, but if found it beneficial to every description of crop, and so combined with other chemical materials it might, he effective that, where it was applied in considerable thought, be advantageously used for disinfecting the quantities, he had seen its effects on subsequent crops for sewage before it reached the larger reservoirs, or even in three or four years. Having a piece of land undone, and the reservoirs themselves. He thought that a mistaken comparing it with that which was done, the result had notion prevailed as to the injurious effects that would been unquestionable for several years. If they result from these sewers, for he had reason to believe that doubted the power of the soil as a deodoriser, the effects were not so bad as when the sewage was spread they had only to get some game that was high, over the surface of the land. No doubt, as Mr. Sheriff wrap it in a cloth, and cover it with a few shovels- Mechi had stated, the earth was the best deodoriser, but full of earth, and, in half an hour, they would the great object was to deodorise long before the sewage find that all unpleasant smell was removed. A labourer reached that destination. in his employ had assured him that when he used to be engaged in cutting up carrion for feeding hounds, the only way in which he could remove the smell from his hands was by washing them in clay water. But before they could apply liquid manure to clay lands they must be well drained. On chalky, gravelly, and sandy soils, they might put any quantity of liquid manure with effect, especially for those quick-growing crops which consumed large quantities of food by their rapid growth. But the great question was, to persuade the agricultural public that it was to their interest to use this description of manure. If sewage was profitable to be used by the farmer, it was useless unless the agricultural public were prepared to lay down the pipes to bring it upon their land. This could be done at a cost of something like £6 per acre. Having adopted the system himself, he could state as the result of his experience for the last four years, on his farm of 170 acres, that it was a most profitable operation. Applying the water of London alone-even without the 12,000 or 15,000 tons of ammonia-over properly drained land, would be profitable. The water meadows of Winchester and the Duke of Portland proved this. It had been said that liquid manure was not available during wet weather or frost. He would say that it could be applied in any weather except very severe frost, and even during frost it often had the effect of softening the ground. He hoped never again to hear it asserted that water cannot percolate through the stiff clays, for unless that notion were exploded, it was in vain to hope that agriculturists would apply the sewage of towns upon clay lands. The cost of its application was no longer a matter of doubt. There was a vast amount of prejudice to be got rid of before sewage manure would be of extensive application. Of its value there could be no question. London at the present time contained about an eleventh part of the population of the whole country, and probably the produce of one-eighth of the whole area of land was exhausted to feed London alone. The importance of a good manure would be fully appreciated by those who had to resort to expensive foreign manure to supply the exhaustion of the land in feeding the population of this metropolis. With regard to the deodorising process at Leicester now advanced, he would state that it was contemplated to carry it out at Chelmsford; originally it was intended to lay down a system of pipes and works for the purpose of irrigating the land, but there was at present a difficulty in obtaining the land required for the purpose on such terms as would justify the outlay. Mr. WRIGHT said, although a member of the Metropolitan Board of Works, he was not there to defend that body. It was a favourite practice to point out in strong language the enormous amount of fertilising matter that was lost under the ordinary system of town sewage. He appealed to the chairman, as a chemist, and one acquainted with manufactures, whether the cost at which it could be saved was not an essential element in the question. Quartz might contain gold, but in so small a proportion that it would not pay the expense of extraction. He applied that remark to the subject before them. Until it had been shown that it would cost less to abstract the valuable matters in the sewage than the value when extracted, they must adopt the best plan they could for getting rid of it. He would instance ammoniacal liquor of gas works. The ordinary strength of that product in gas works was, that it took about 16 ounces of sulphuric acid to saturate a gallon of the liquor, and thus form a salt of ammonia. It was more profitable to sell it for a low price to parties who took it away from the gas works and manufactured from it a valuable chemical salt, than for the gas company to attempt the manufacture themselves. But the manufacture could not be carried on profitably if the dilution exceeded a certain per centage. Now the per centage of ammonia in sewage was infinitely less than in any ammoniacal ever made. He had hoped for more detailed facts as to the expenses at Leicester. If, as was stated, they were selling it at 2s. per ton, could they buy lime for the process at 2s. per ton? Those were the practical questions which required to be answered. He thought, that after the diversity of opinion they had heard that evening, to ask the Metropolitan Board to rush into this scheme, would be asking more than practical_men of business would be inclined to concede. The Board of Works were doing all they could to bring the sewage to one or two points, and when there it could be operated upon. He would appeal to this large audience, whether what the Board were doing was not something like that which business men should do? Dr. COPELAND remarked, that in his opinion, if Mr. Bazalgette's plan of intercepting sewers were carried out, it would be a failure, injurious to the health of the metropolis, and would entail double the estimated expense. The subject of deodorising—or, more properly speaking, disinfecting-was one of great importance; for, unless that were done, no sanitary improvement would result. Mr. WILKINSON said he belonged to an increasing He objected to the use of quick-lime in the process, in-section of the Metropolitan Board, who believed that in asmuch as it set free the ammonia, whereas he would suggest the use of carbon (carbon being a fixer of ammonia), and the result would be a more useful manure. deodorising would be found the successful solution of the great question of the day. He contended that they had nothing to do with the commercial consideration of the question. The question was how they could most efficiently, in a sanitary point of view, effect the complete drainage of the metropolis. The Board of Works might be considered as a jury upon the question, and they wanted evidence to guide them. He could confirm all that had been stated by Mr. Cooke with regard to the sanitary effects of that system upon the town of Leicester, and the process might be carried on under their drawingroom windows without offence to any one. He considered the most magnificent results had ensued in a sanitary point of view from the adoption of the deodorising process; and as the representatives of the sanitary interest of the metropolis, it was the duty of the board to pause before they committed themselves to the vast expenditure proposed. They ought officially to send proper persons to examine carefully into this process. He (Mr. Wilkinson) was not wedded to any particular plan, but he believed that the deodorising principle would enable them to do the work most effectually and economically. He considered that it ought not to be thrown upon the Board of Works to determine this great question; it would be more satisfactory if a special commission were appointed for a work of such magnitude, which commission should embrace the best engineering and chemical talent of the day. He dissented from the opinion just expressed, that because the products were not at present commercially valuable, the deodorising principle ought not on that account to be considered by the Metropolitan Board. Mr. RAWLINSON said that it was now pretty well decided that towns must be sewered, and houses must be drained, if health was to be preserved, and for that purpose the accumulated sewage must be disposed of; and as there were cases in which an immediate application to the land could not be made, some form of deodorising would be necessary. He (Mr. Rawlinson) could only say, that if the Leicester plan did not fully answer the purpose he was sorry to hear it, and most earnestly hoped all objections might be removed. Mr. Cooke had imputed the saving of life in Leicester to the deodorising. As this might be objected to, he begged to say that sewers and drains, without the deodorising works, had brought about equally beneficial results, and he only mentioned this fact that the arguments in favour of deodorising might not be weakened. The question should not be one of cost alone; if absolutely necessary to the health and comfort of the people, the work ought to be made compulsory, and a rate should be levied for the purpose of defraying the expenses. Much had been said about the proposed metropolitan works, and their great costif great works were to be carried out, the cost must be great, but not greater than the benefits to be conferred. ther fresh or in a decomposed state, in such a manner that the great material which gave its value to guanoammonia-passed away, and was lost. The lime did little more than precipitate the matters mechanically suspended. Another argument was, that the mortality of the town of Leicester had been very considerably reduced since that mode of disinfecting the sewage had been introduced. The tabulated return before them. would at first sight indicate that fact, and if they relied upon it, they might conclude that the health of the town had progressed, pari passu, with the introduction of this system. But let them look at the other towns in the North-Midland counties, and they would find that there also, in precisely similar proportion, had there been an improvement in the state of the public health.. By the returns of the Registrar-General for the last three years, he found that the improvement in the health of Leicester-upon which so much stress was laid, as connected with this particular system-was precisely the same as that which had taken place throughout the whole of England; thus the argument failed. He was therefore of opinion that the two points to which he had directed his remarks, viz., the chemical principle involved, and the sanitary result claimed, were not founded upon those sure data on which such schemes ought to be based, in order to gain attention as applicable to the exigencies of the metropolis. Mr. COOKE said that the length of the discussion and the lateness of the hour would only admit of a very brief reply to the comments of the various gentlemen who had addressed the meeting. It had been said that he had ascribed the diminished number of deaths at Leicester to the system of deodorisation alone; but that was an error. He had ascribed this all-important fact to the general sanitary measures adopted at Leicester. It was true the putrid river Soar of former days had, since the erection of the deodorising works, become a pure stream of wholesome water, and the sickly residents on its banks had become healthy. This was a remarkable coincidence, at least. It had been said that quicklime liberated the ammonia of the sewage, and that the Leicester plan was, therefore, chemically wrong. He (Mr. Cooke) had stated that it was cream, or hydrate of lime, that was employed, and that the ammonia, in consequence, could not be, and was not, liberated by the process. It had been said that the chemist of the Agricultural College at Cirencester declared that in the dry bricks there was only 72 per cent. of ammonia. He (Mr. Cooke) had shown that the dry brick lost its ammonia, and should not be taken as the product of the system. It had been said that the process was a fallacy, and the product worthless, because it did not sell. He (Mr. Dr. LETHEBY said, as the Medical Officer of Health for Cooke) had stated that it did sell, at a price that covered the City of London, he had looked with great interest at the outlay in production, and that 1,000 tons had been every scheme which had been advanced in order to effect the sold in the last fortnight. He was told that there was a complete drainage of the metropolis, and he, in common fallacy in valuing the ammonia in manure at £60 per with others, had devoted considerable attention to the ton, as that was the price of the pure article. He replied, question raised as to the effect of lime upon the sewage how, then, was guano valued? It contained sixteen per of the metropolis. Without entering upon the en- cent. of ammonia, and sold in the market in proportion gineering part of the subject, he would direct his atten- to the quantity of ammonia in the sample. He was tion to the two chief arguments that had been advanced charged by a member of the Metropolitan Board with in favour of the scheme then brought before their notice. trying to force his plan upon the board. It was not his One related to the chemical influence of the lime. The plan, but that of the board-of their engineer, Mr. constituents of the sewage of towns consisted for the Bazalgette-who recommended it for the western district, most part of undigested matters, and when those were because "he had ascertained that the cost of the process acted upon by lime-whether they were in an undecom- of purification would be very much less than that of posed state, or in a putrescent state, the lime precipi- conveying the sewage to Barking-creek." That this tated the phosphates, which, in the act of falling, carried circumstance mainly influenced him, although the mechanically other matters existing in sewage waters, and increased engineering difficulties attendant on the other there were left urea, uric acid, and other substances of scheme had some share in forming his decision, and that value, wholly untouched. The process, therefore, he con- the amount of saving in that district alone would be sidered deficient in the first principles of chemistry. He need £12,000 per annum; and Mr. Bazalgette afterwards stated not say that the action of lime upon the various consti- that if his (Mr. Cooke's) proposition for deodorising at tuent matters of sewage water was well known to chemists; the Lea river were adopted, "a further saving of nearly but he had himself put it to the test of experiment, and half a million might be effected." It was said that the he found that lime acted upon the sewage matter, whe-plan had failed at Southampton. This was an error. prevented him taking part in the discussion, but he did The Secretary announced, that on Wednesday next, the 17th inst., a paper by Professor Owen, F.R.S., " On the Ivory and Teeth of Commerce," would be read. The following letters have been received since the meet"Sir,-There was no time for practical farming men to make any observations last evening, otherwise I should have stated that since I have been engaged in farming on rather a large scale (farming 560 acres), I have been for manuring and enriching my land at the least cost; constantly studying all the different modes now known and with respect to the manure made by Mr. Wicksteed's process, I should say that it is with the farmers merely contains 73 per cent. of ammonia and 12 per cent. of aniIf Mr. Wicksteed's solid manure a question of cost. mal matters (as the analysis of Mr. Voelcker proves) then The authorities had not adopted the plan, and their one ton of it is worth to the farmer as much as 100 lbs. of guauo; and if the farm is near to the works, it may be cheaper for him to buy and distribute on his land 341 tons of this manure, than 3 cwt. of guano; but that cost depends, of course, on the distance and expense of carrying this manure on to his fields. The great advantage of applying liquid manure by pipes, is the small distribute manure at a cost of 14d. per ton; whereas the cost of its distribution, as the engine will pump up and carting of solid manure alone from the farmyard on to the helds and distributing it, will cost 4s. per ton. Also, when the manuring principle is applied to land dissolved in water, it permeates more rapidly through the soil, and becomes more quickly combined with it, than when put on the land in a solid state; and until the manuring principle has chemically combined with the soil, the food for plants is not produced. Professor Way has shown us, by one of his most valuable experiments, that when inches of earth, containing such usual proportion of liquids, containing ammonia, are filtered through six alumina as for that purpose. The CHAIRMAN said it only remained for him to move a vote of thanks to Mr. Cooke for his very valuable paper. With reference to the discussion that had taken place, he would allude to a matter in which he had been is retained and chemically combined with the alumina, all corn lands have, all the ammonia personally appealed to by one of the speakers, viz., that and the liquid is discharged free from it, wherefore it is this question ought not to form a large subject of investigation because capital had not yet used it for speculative and, as is now the custom, to apply guano to the land in more desirable to apply the manure dissolved in water, purposes. The whole history of manufactures was but wet weather, that its ammonia may be quickly washed the using up of waste materials for a long time unrecog; in; and I may here remark, in answer to one gentleman's nised by capital, but which ultimately had produced observations, that Mr. Way has found that peat charcoal the most important benefits to mankind. If such were has not so good an effect in arresting ammonia from the result of manufactures, surely the opinion of che-liquids as common earth, and it is therefore of no value mists that this material contains valuable properties for the food of our population, ought to receive more attention from capital, and they ought not to be deterred by any general statements that sewage manure could not be made valuable. He thought Mr. Cooke's advice, to refer the question to a commission of scientific men was better than that he had employed in his reply. He quite agreed that whilst they ought not to allow scientific men to be their masters, they ought to make scientific men their advisers. In carrying out the electric telegraph, Mr. Cooke, who knew much of the science of the subject, did not hesitate to avail himself of the scientific discoveries of other persons, or to employ their counsel in guiding him, and it was this, united with his own energy and power of business, which had led to such a successful result. The fact of his being in the chair had "If I could get a supply of liquid manure brought to my farm, I should be glad to receive it, and would distribute it over my land; but until that can be done, I see solid manure, if its cost per ton, when put on the land, no reason why farmers should not use Mr. Wicksteed's will not exceed the cost of 100 lbs. of guano. But, of course, if by Mr. Wicksteed's process the per centage of ammonia can be increased, its value to the farmer will also be greater. "I am, &c., JOHN BETHELL." "SIR,-In Mr. Cooke's paper of yesterday it was asserted that Mr. Wicksteed was the inventor of the lime process for deodorising and precipitating sewage.' "As long since as 1847 a court of inquiry, consisting of the chairman of the meeting, Dr. Lyon Playfair, together with Sir Henry de la Beche, and one or two others, examined into my own invention on this subject, and reported, That it was a proper subject for an Act of Parliament,' which act was passed in the same year. Mr. Wicksteed was on that occasion heard by counsel before that court, which, however, decided in my favour. "It was impossible for me last evening to call attention to my claims, which, however, I trust you will allow to appear in the same Journal which contains the report of last evening's proceedings. By so doing you will much oblige Yours, &c., 66 "WILLIAM HIGGS. "24, Churton-street, Pimlico, Dec. 11, 1856." HONORARY LOCAL SECRETARY. The following gentleman has been appointed Honorary Local Secretary for Manchester : George Peel, Manchester. EXAMINATION PRIZE FUND. Sir J. W. Ramsden, Bart., M.P., £105. Home Correspondence. oil, Mr. Binks will find a paper by Messrs. E. Barruel and F. CRACE CALVERT. DRYING OILS. SIR, The desire to hear what the manufacturers of boiled oil and varnish had to say on the subject of Mr. Binks' paper, and the lateness of the hour, prevented my making any remark, as a consumer of both articles, as to their present defective points. All persons interested in their use must hail with satisfaction the prospect of being able to procure a pale or colourless drying oil at a moderate price, difficult as it is to believe that mixing an oil of nearly the colour and consistence of treacle, will not injure the purity of white and other delicate paints; the mere opening a discussion on the subject, and giving consumers an opportunity of expressing their wants, will probably lead to improvements. In fact, it appears that the difficulty of procuring a colourless drying oil, has prevented varnish makers making any considerable improvements in copal varnishes for carriages during the last thirty years. From all the information I can obtain on the subject, the only advance made during that time, is, that many manufacturers can now produce as good an article at a lower price, as was only made by one house thirty years ago; the colour is still dark, and injures delicate paints. At the time I was occupied in preparing the report on the carriage department of the Paris Exhibition last year, and obtaining information connected with the deColin and Co., of Breslau, Silesia, samples of pale tails of manufacture, I found exhibited by Messrs. J. First, with borate of manganese. Third, without heat. Can Mr. Binks inform us if he has tried any of these methods, or will any manufacturer try them, and give us the result of his experiments?-I am, &c., 28, Haymarket, Dec. 5. GEORGE N. HOOPER. TECHNICAL WORDS. REMARKS ON MR. C. BINKS' PAPER. SIR,-I was much surprised, on reading Mr. C. Binks' interesting paper "On some New Methods of Treating Linseed Oil," &c., to find that he had so completely overlooked several valuable memoirs which have been pub-drying oils, prepared in three manners. lished on the very subject of his discourse, not only as to the method of investigation, but also the very substance he recommends to impart to linseed oil rapid drying properties. No one less deserves the following sweeping remarks of Mr. Binks than my master, M. Chevreul: -"But the labours of Chevreul went to determine their chemical constitution, not to investigate their peculiar changes under all kinds of extraneous action, and the peculiar chemical history of the changes the drying oils undergo formed no part of his admirable researches;" for M. Chevreul began to investigate fully the phenomena of the drying of oils in 1845, and published a most extensive and valuable paper in the Memoirs of the Academy of Sciences, 1850; and Mr. Binks cannot plead that this paper could not be known by him, for, after I gave my lecture at the Government Department of Science and Art, Marlborough House, Mr. Hart kindly undertook to make an extract of it, which he published in several numbers of the Builder, see Vol. XIII., pages 109, 193, 243, and 373, 1856. If Mr. Binks will read M. Chevreul's Memoirs, he will find that this learned chemist investigated the drying properties of oils exactly by the method claimed by Mr. Binks, and he will find that M. Chevreul made and described several hundred experiments. My master not only examined the various atmospheric influences which assist or impede the drying of linseed and other drying oils, but also the action of the same when boiled with litharge, or oxide of manganese, the influence of various pigments on the same, and lastly, the action which various surfaces have in facilitating or retarding the drying of oils. SIR,-As I am about to publish a Supplement to my · English Dictionary," I shall feel much obliged to any Members of the Society, or readers of the Journal, who will favour me with additional words, and particularly trade terms.-I am, &c., As to the employment of the hydrate of protoxide of iron, or nickel, and especially that of hydrate of protoxide of manganese, for imparting at natural temperatures, or at a moderate heat, drying properties to linseed 42, Basinghall-street, 6th Dec., 1856. HYDE CLARKE. THE PRICKLY PEAR. SIR, The juice of the fruit of the prickly pear, the Cactus opuntia of some botanists, and Opuntia vulgaris of others, which you forwarded to me some time back, with a request to ascertain its properties as a dye, has, so far as the quantity sent would admit, been submitted to different trials upon cloth, both woollen and cotton, without mordaunts and mordaunted. The juice, although of itself a beautiful deep, rich, purple rose colour, did not, under any circumstances, convey this tint to the material with which it was tested. Cotton cloth prepared with different mordaunts took up colour in a very imperfect manner. The shades varied according to the mordaunts employed, and were from a grey to a brownish black. All were of a dull hue, and unstable, being removed to a large extent by boiling with water only, consequently of little or no value. With woollen cloth mordaunted I was more successful, and with a mordaunt of a tin salt I secured a bright blue black colour, which was comparatively stable, and resisted considerably the soap bath. I am sorry to say, however, that time has the effect of changing the colour of this cloth. The piece accompanying this, and which you will notice is of a dull brownish purple colour, was the same which I exhibited to you about six weeks back, and was then, as you may remember, of a rather beautiful blue black. I am, &c., DUGALD CAMPBELL. 7, Quality-court, Chancery-lane, Dec. 4, 1856. MEETINGS FOR THE ENSUING WEEK. MON. London Institution, 7. Dr. Tyndall, "On the Nature and Architects, 8. Mr. Owen Jones, "On the Leading Principles TUES. Civil Engineers, 8. Anniversary. Linnæan, 8. Pathological, 8. WED. London Institution, 8. Conversazione. BRUSSELS ECONOMIC EXHIBITION. SIR, I find that I was misinformed when I stated, in my report on the Brussels Exhibition of Domestic Economy,* that the article on the Building Department, which I quoted from the Builder of Oct. 4, was by H. Roberts, Esq., the honorary secretary of the Labourers' Friend Society. I am not aware by whom that article THURS. was written, but I am told that the sum allotted by the French Government towards the erection of workmen's houses in France was 10,000,000f., instead of 1,000,000f. I am, &c., T. TWINING, Jun. Perryn House, Twickenham, Dec. 3, 1856. EXAMINATIONS. SIR,-A letter appears in the Journal of the Society of Arts of Friday last, in which the writer expresses his regret that the Council have resolved to exclude certificated masters from their examinations. It seems to me that three reasons may be assigned to justify them in coming to such a decision: 1. It is unnecessary to provide examinations for that portion of society. 2. It would be unfair to those for whom the examinations have been established. 3. It would tend to bring the Society of Arts into direct collision with existing institutions. The intention of the Council has been to supply a want of the age, and whilst they keep this object steadily in view they will not fail to command the respect and support of the more thoughtful part of the community.-I am, &c., ROBERT HONEY. Cowper's House, Huntingdon, Nov. 24, 1856. RAILWAY ALARM FOG-SIGNAL. SIR,-My attention was engaged to make an improvement in alarm-signals for railways in consequence of the terrible disaster on the railway near Straffan, in Ireland, nearly three years ago. Colonel Beamish, director of the Cork and Bandon Railway, had six fog-signals placed on the rail at the Cork terminus, and when the engine passed over them two or three failed to explode. I requested that one, which was not tested, should be opened, and I found that the gunpowder within was caked, as if from damp, the three iron nipples were rusted, and the percussion caps on them rendered defective from verdigris; the circular tin case was also nearly eaten through with rust. Recollecting that the composition with which I charged my rifle percussion-shells, as far back as the year 1823, made a louder and a sharper report than any gunpowder I could find, I thought this composition-equal parts by weight of chloride of potass and sulphide of antimony, both pulverised-would be the best adapted for charging my fog-signals, which are made of paper, varnished over to make them water and damp-proof; they are exploded by means of my patented glass tube-ignitor, which cannot take rust or become impaired by any length of time in keeping. The weight of my signal is not quite half that of the tin signal now in use, while its report is louder and sharper. I am, &c., J. NORTON. *Journal of the Society of Arts, Vol. IV., p. 781. Society of Arts, 8. Professor Richard Owen, F.R.S., "On the Ivory and Teeth of Commerce." Geological, 8. I. Captain Spratt, "On the Tertiary Freshwater Deposits of the Western Portion of the Grecian Archipelago." II. Mr. John Wolley, "On an Ice-carried Boulder at Borgholm." III. The Rev. Mr. Clarke, "On the Occurrence of Volcanic Bombs in Van Dieman's Land." IV. Dr. Richardson and Mr. E. Browell, "Analysis of Waters from the Turko-Persian Frontier." Messrs. Hillier and Moyle, "On some Minerals from Siam.' Royal Society Club, 6. Numismatic, 8. SAT. Asiatic, 2. London Institution, 3. Mr. T. A. Malone, "On Experi- |