NEWS -namely, in the introduction of a small glass reservoir between the upper surface of the filtering medium and the surface of the water in the vessel in which the medium is placed. A small stopcock in the top of such reservoir would allow of the expulsion of any accumulated air on merely closing the orifices of outflow. For example, the carbon block and casing of the cistern-filter' of Messrs. Atkins might have such a reservoir placed above the centre of the block, communicating with a glass tube and cork with the central cavity of the block. Fifthly, since writing this paper, and only a few hours before its delivery, Mr. Schacht has told me that his original idea in devising the form of filter he described at Birmingham, was simply the production of an aerostatic instrument, the hole in the upper part of the chamber beneath the filtering medium being placed there to admit of the long tube being conveniently filled, and not to ensure the removal of every trace of air from that chamber. On examining the filter he brought to me, I at once saw that all the air was not removed, that sufficient remained to interfere with, though not to destroy, the continuity of the column. I would, therefore, more distinctly than in the last paragraph, propose an improvement in his filter. I would suggest the blocking up of the small side-hole in his instrument altogether, and the adoption of a narrow channel of communication from below to above the medium, terminating in a glass flask and stopcock as already described. The plane of the perforated metal plate on which the medium rests, might be slightly inclined, and the small channel be then at the side rather than in the centre of the medium." The discussion on the paper was postponed until the next meeting, but Mr. Schacht explained the principle of his filter, and Dr. Redwood addressed a few observations to the meeting, in the course of which we understood him to say that Dr. Attfield's observations and experiments had nothing to do with filtration, properly so called, but were concerned with the rate of flow under different conditions and circumstances. BRISTOL NATURALISTS' SOCIETY. December 7. A PAPER was read by Mr. HENRY BRIGHTMAN "On the Application of the Photographic Printing Process for Producing Copies of Botanical and other Specimens." To lay plants, &c., upon prepared paper, and expose them to sunlight, was a method which had been frequently practised, but the pictures so obtained were, technically, negatives, the representation of the object being white, on a dark ground. It occurred to the author that if these could be rendered transparent positives might be printed from them. He found, however, that this could be readily done without any previous preparation of the negative, and he exhibited a number of very beautiful photographs produced in this way of ferns, leaves, and even a butterfly's wing, showing the wide applicability of the process. Brightman then described the process in detail; for the negatives the albumenised paper should be as thin and free from grain as possible, and sensitised by floating on a 60-grain solution of nitrate of silver. An ordinary printing frame was used, but a very long exposure was requisite, especially for positives, and this constituted the chief objection to the process, where many copies were required, as for illustrating a book. The toning bath contained half an ounce of acetate of soda to one pint of water, and one grain of chloride of gold for each sheet toned. The picture was fixed with hyposulphite of soda (eight ounces to the pint), and well washed with water. Mr. Much conversation then took place on this paper, in the course of which Mr. Beattie urged the employment of waxed paper, instead of albumenised, as likely to give a more transparent negative; and spoke of the application of carbon printing to this process. Mr. Brightman suggested the use of a green instead of a black pigment in that method, to give the natural colour of the plant. Mr. Ravis mentioned the expense of the silver process as an obstacle to its employment on a large scale. The possibility of printing negatives on dry collodion or tannin plates was suggested. December 13. Mr. W. L. CARPENTER read a paper on "Pharoah's Serpents' Eggs," the chemical toy now so common, and gave the results of experiments that he had made to known, the white powder forming the egg was sulphoascertain the composition of the serpent. As was well cyanide of mercury, and the author described several modes of preparing it. Theoretically represented by the formula HgCyS2, it would contain 633 per cent. of mercury, and the specimen he analysed yielded 64'9 per and as the product contained 70'5 per cent. of mercury, it cent. The loss of weight on burning was 19:27 per cent., followed that about one-seventh of the mercury in the egg the serpent form was not, as was generally supposed, caused was volatilised. He showed an experiment to prove that by the cone of tinfoil, and described others which led him to believe that the blackness of the inside of the serpent with mellon, or melam, products of the decomposition of was due to the mechanical mixture of sulphide of mercury The brown exterior contained no sulphide of mercury, and, the sulphocyanides which had been studied by Liebig. tion in which sulphuretted hydrogen caused a yellow when treated with nitro-hydrochloric acid, yielded a soluflocculent precipitate, the nature of which he had not ascertained. The specific gravity of the serpent was o'o69, skin that no air escaped through it when the serpent was water being 1'000, and such was the continuity of the sunk in water. by Mr. P. J. Worsley, showing what facilities the paper Mr. CARPENTER then exhibited a photograph, sent process gave for getting quantity, and also the desirable quality of size, as well as the advantages over working with glass plates as regarded portable apparatus. A friend of Mr. Worsley's had taken out, on a trip, seventy sheets ready prepared by the turpentine waxed paper process, and had had no failure among them, although the exposures varied from five minutes to four hours. Mr. NOBLE, the Secretary, exhibited a series of very beautiful paper negatives, taken by Mr. West, of the Clifton Observatory, of large size. The process was the ordinary iodized paper one, the sheets being waxed either before or after exposure, no preference being given to either. It was generally allowed by those present that where long exposure and slow development were possible, no process tainable by it. was equal to this for the exceeding beauty of detail ob CORRESPONDENCE. The New Metric Standards. To the Editor of the CHEMICAL NEWS. SIR,-Referring to the proposal made by Mr. Yates at public exhibition of the yard and metre in juxtaposition the Chemical Society's meeting of Thursday last, for the yard be made of stout ruby glass (flashed), and the French as mural standards, I beg leave to suggest that the English metre of white glass, superficially coloured with cobalt blue. panying verbal descriptions, may then be produced by grindThe requisite lines and divisions, as well as the accom ing away the coloured surfaces in a manner so frequently practised in ornamenting vases and other works of art. present a more attractive appearance, would expand by Such materials would be incorrodible, like porcelain, and heat much less than metals, and offer less temptation to have been favourably spoken of for these purposes. the London thief than the platinum or gilt bronze which I am, &c. F.C.S. December 27. Estimation of Sulphur in Mineral Waters. To the Editor of the CHEMICAL NEWS. SIR,-Having lately been engaged in the examination of a mineral water in which I am somewhat interested, and which possesses the strange combination of sulphate of iron and hydrosulphuric acid, I met with considerable difficulty in employing the usual tests for the estimation of the HS. No estimation with silver could be attempted on account of the reducing agency of the Fe"Se, Dupasquier's method was rendered uncertain by the same cause, and the liquid, moreover, when even moderately heated, assumed the troublesome red tint which it is liable to do when heat is obliged to be employed and the solution to be tested is acid. Arsenic was inapplicable on account of the small proportion of sulphur present, when I bethought me of the following simple method:-Some sulphate of lead was prepared by precipitation from boiling solutions, and was well washed with boiling distilled water, and while still fresh and moist successive portions were added to the mineral water till the brownish-black colour of the precipitate first formed turned to a decided grey, showing that the HS had all been removed from the solution and that some undecomposed lead salt remained in excess. The supernatant liquid was decanted from the precipitate, which rapidly settled down, and the latter was rapidly washed on a filter with boiling distilled water, and subsequently with hot solution of acetate of animonium, till the washings were no longer coloured by the addition of an alkaline sulphide or by HS. The filter was now carefully incinerated, and the Pb's was oxidised by an addition of a little HNO, and evaporated with a little HS until heavy fumes of the latter began to be evolved. Subsequent dilution with water gave a precipitate of Pb's which was separated by decantation and weighed, and from this was calculated the amount of II, which had been present in the water. I enclose a small book containing the analysis of this interesting source, by Professor Filhol, and which may perhaps interest you. I am, &c. Bagnères de Bigorre, December 16, 1865. F. MAXWELL LYTE. Cleaning American Clocks with Soda. To the Editor of the CHEMICAL NEWS. SIR,-Some of your readers were doubtless amused some time since by seeing a paragraph in the papers headed "How to Clean American Clocks." I did as directed, boiled my clock for some hours in caustic soda, washed copiously, hung on the jack, and dried quickly. The clock was an eleven-shilling one, gone regularly for ten years, but lately taken to stopping through clogging up of the pinions; it has since behaved itself well, gone regularly, and keeps good time. The treatment is peculiarly applicable to these clocks, for, owing to their low price, our professional clock-cleaners do not care to meddle with them. I am, &c. CHEMICUS. London. MISCELLANEOUS. Observations with the Water Barometer.Mr. Bird, of Birmingham, sends us the following:-On Tuesday night last, December 12, the tidal column rose to 406 inches, being the highest I have ever observed, showing an extraordinary increase in the atmospheric pressure. On November 27 the water stood at 374 inches; it had, therefore, risen on Tuesday last to within 4 inches of 3 feet, showing that there was added to the atmospheric pressure a weight equal to a column of water nearly a yard high and equally spread over the whole country, the height of the water being actually visible to the eye in the water barometer. 406 inches is 33 feet, the highest that a pump would work, last Tuesday. Dr. Hofmann's Reply to Dr. Phipson.-We have received an article just published by Dr. Hofmann under the title, "Aufklärung für junge Chemiker," in reply to Dr. Phipson's "Warning to Young Chemists," published in Cosmos. We regret that the pressure on our space prevents us from inserting a translation in this number; but it will appear in full in our next. Metallic Titanium.-Within the past few months titanium metal is stated to have been obtained in considerable quantities in Birmingham, by reduction with sodium, the resulting powder being fused into compact masses of large size; the similarity of titanium and iron is striking. Little doubt is entertained that ere long the new metal will be produced at about the price of silver, in which case many practical applications could, probably, be found for it. The metal is largely disseminated in nature, so that once introduced a constant supply could be depended on.-Mining Journal. Simple Method of Preventing Boiler Incrustations.-In a manufactory at Lorenzchacht they use water holding a little clay in suspension, and after three months' work find on the sides of the boiler only a little mud, which is easily scraped off. This mud is nothing more than the clay itself, which prevents the deposit of crust mechanically by keeping the particles of deposited matters apart. Process for Rendering Wood Plastic."-A very simple method of rendering wood plastic has recently been discovered. It consists in injecting diluted hydrochloric acid into the wood under a pressure of about two atmospheres. The duration of the operation must be regulated by the nature of the wood, the bark is not removed, and by a very simple arrangement the liquid injected at one extremity may be partially collected at the other. If the green wood is submitted to pressure, the cellules having been previously washed with water, it may reduced to a tenth of its original size; the fibres may be excessively compressed without breaking or tearing, and when dry have no tendency to resume their natural condition. Woods treated in this way will serve for many purposes. If after the treatment with hydrochloric acid the wood is washed and dried, it may be cut and chiselled with great facility, and serves admirably for sculptural purposes. The wood is dried by passing air under pressure through the cellules at about 37°, the moisture is rapidly expelled, and as the mass contracts evenly throughout, there are no cracks. Colours or the various substances which prevent wood from rotting may be injected in a similar manner; soluble glass or freshly precipitated silica renders it very durable and at the same time incom bustible. ANSWERS TO CORRESPONDENTS. ** All Editorial Communications are to be addressed to the EDITOR, and Advertisements and Business Communications to the PUBLISHER, at the Office, 1, Wine Office Court, Fleet Street, London, EC. Private letters for the Editor must be so marked. Vol. XI. of the CHEMICAL NEWS, containing a copious Index, is now ready, price 118. od., by post, 118. 6d., handsomely bound in cloth, gold-lettered. The cases for binding may be obtained at our Office, price 18. 6d. Subscribers may have their copies bound for 2s. 6d. if sent to our Office, or, if accompanied by a cloth case, for is. Vols. I. and II. are out of print. All the others are kept in stock. Vol. XII. commenced on July 7, 1865, and will be complete in 26 numbers. INDEX. ABEL, Mr. T. A. on compounds of 45, 69, 93, 106, 119, 130, 155, formic, new mode of preparation, nitrous, formation from am- phenylo-phosphoric, 283 phosphoric, strength of various pyrogallic, new mode of prepar pyrophosphodiamic, 283 Acids belonging to the acetic, lactic, hy driodic and hydrocyanic, a Air of mines, pressure and tem- pump, a new, with a free piston, supposed nature of, prior to the discovery of oxygen, 62, 74, 293 Alcohol, a new, in which part of 238 methylic, detection of, 268 detection of in chloroform, &c. 153 Alcohols, caprylic and oenanthylic, 224 Aldehydes, action of, on rosaniline, 159 Alizarine, preparation of, 296 Aloes, action of chlorine on, 230 Alumina and its compounds, indus- trial preparation of, and on hydriodates of, 202 Ammonia, chlorothallate of, as a and nitric acid, series of bodies manufacture of carbonate, 303 remove sulphur from gas, 277 of the Montpellier saline chaly- of waters, 87 Aniline, action of monobromacetic action of nitrous acid on, 82 Animal chemistry, on, 30, 39, 52, 65, Annaies de Chimie et de Physique, 137, 180, 240, 275 of explosive gases in mines, 280 36, 48, 60, 72, 84, 96, 108, 120, 182, 146, 158, 170, 182, 194, 206, on several compounds of penta- plosive gases in mines, 280 238 on the nature of white phospho- Baumert, Professor, death of, 169 Bechamp, M. on the ageing of wines, on exhaustion and vitality of beer on variations in the amount of thermo-electric piles of sul- Benzoic alcohol, amines of, 10, 37 of, 251 Bérard, M. A. on a new direct | method of producing cast steel Brightman, Mr. process for copying Bristol Medical School, 143 money grants of, 170 Medical Association, Letter to the Pharmaceutical Conference, 108 Bulletin de la Société de Chimique Bultinck, M. use of magnesium in Bussy, M. and M. Buignet, on the action of tartaric acid on neu- and steel in state of fusion, 252 Carbonic acid, physiological action Carmichael School of Medicine, 145 Carret, M. on the new epidemic in Caseine, affinity of, for bases, 70 Catholic University, 145 treatment of, with alkaline sul- Cement, Armenian or diamond, 218 Cerium, new British mineral con- Chapman, Dr. E. contributions to on detection of antimony in tube on detection of copper in iron Dr. John, Diarrhoea and Cholera, Mr. E. T. on caprylic and œnan- Charcoal, absorption of vapours by, 224 Charing-cross Hospital and College, 141 Cheese, on the changes which it 243 Chloromelanite, 119 Chlorophyll, chemical properties of, 119 Chlorothallate of ammonia as a re- Chloroxynaphthalic acid, manu fac- Citrate of iron and quinine, quan- City of London College, 142 prevention and cure of by copper Chromates, volumetric method of Church, Prof. A. H. chemical re- ethers of the formic series, 146 remarks on Warren's researches H. J. skeleton leaves, 95 Clay and glycerine for modelling, 242 College of Chemistry and School of Physicians, 30, 39, 52, 65, 76, 89, Collin, M. on animal heat and the Congelation of animals, 263 and phosphorus, compounds of, 172 telluride of, 108 smoke question, 96, 277 Crystalline force, 236 Crystallised protoxide of copper, Curarine, physiological effects of, 10 DAMOUR, M. on the chemical com- position of the stone imple- in the production of milk, 81 49 Decanter, a new, 218 Deleuil, M. a new air-pump with a De Luynes and Esperandieu, MM. Deschamps, M. on absinthe, 33 Cosmetics, &c. 229 ment of biphosphate of alumina on the industrial preparation of Dextrine, 275 of electro-negative elements on Dialysis in relation to physiology Diamond cement, 218 expansion of the, under the in- 183 Discoveries in physiological che- Disinfection, processes of, 48 14, 28, 38, 51 reports of the juries, 191 EGGS, microscopic examination of to keep, 84 of metalloids, 3 Electro-negative elements, their influence on the spectra of Equivalents, on the cause of nume- and Prof. Wanklyn on the action of hydriodic acid on manuite Esparto fibro, its composition and Essence of cognac and wine, 302 synthetical researches on, 201 Etna, gases evolve 1 from springs around Mount, 130 Excise Laboratory, repert from the periments on the transfusion 145 FAIRY Tales of Science, the, 289 experiments and observations perties of chlorophyll, 119 diamond and of crystallised Fossil, analysis of a fresh-water, 255 springs around Mount Etna, 130 Fractional condensation, process of, 172 Frankland, Dr. F.R.S. constitution of acids belonging to the acetic, on a combination of hydrocyanic Humpert, Dr. T. on the action of and hydriodic acids, 195 of supersaturated solutions, 93 on supersaturated solutions, 252 Gibsone, B. W. a ready mode of 145 Glucose, formation of, by leaves, 292 sugar and, 299 six months, 11, 22, 34, 46, 59, Griffin's furnace, 246 use of, in American mines, 266 HAARHAUS, Dr. hydrazoanilin, 93 Habich, M. on Guyard's process for estimating manganese, 58 mic acid, and on the amount fusible alloys of cadmium, 13 from polished and unpolished internal, of the earth as source of Heptyle, hydride of, from azelaic concentrated sulphuric acid on tion of vapour by charcoal, 224 tion of bromide of potassium, 95 Hydrazoanilin, on, 93 NEWS KELLER, M. on a new property of King's College, 140 Kohler, Dr. on a new transforma- tion of leucin, 46 lisation of mineral matters and LABORATORY and lecture-room, Lauth, M. the reaction of sodium upon pure benzine, 59 visible photographic image, 101 Leaves, asphyxia of, 263 chemical researches on the green minerals, 159 of Lecture illustrations, 42, 55 tion of lithium, ce-ium, rubi- relation to physiology and toxi- on the present state of the che- tion of alkaline nitrates into Leucin, new transformation of, 46 171 attempt to refer some phenomena attending emission of, to Limpricht, M. on phosphoric ethyl- Liquor bismuthi, preparation of, 27 London Hospital, 142 University, prizes and honours at Lorin, M. new method of preparing preparation of formic acid, 119, Luu, M. R. de, on the deposits of Lunge, Dr. American manufacture 230 Lyte, Mr. Maxwell, en estimation MACADAM, Dr. S. results of agricul- on use of esparto fibre in paper, Magnesia, hydraulicity of, 287 use of in voltaic piles, 191 Royal School of Medicine, 143 chloride of, 70 on Guyard's process for estimat- Mayer, F. F. on tobacco, 74, 88 Students, a Course of Practical Mercuric methide, poisoning by, 213 ointment of the yellow oxide of, Metalloids, e'ectro-chemical prepa- Metals, influence of electro-nega- transmutation of, 36 detection of, in chloroform, &c. NAQUET, M on thymotide, 70 on the cause of numerical rela- Nitric acid and ammonia, series of 95 results of explosion of, 193 OCTAVES, law of, 83 Ointment, red oxide of mercury, 250 Osanu, M. on antozone, 82 action of sodium amalgam on of roses, test for, 182 the chemical professorship at, Oxygenated saline waters, 121 does it exist in the air? 274 researches on the density of, 274 the subject of the preservation researches on acetic fermenta- Patent medicines, duty on, 71 155, 169 Phipson, Dr. T. L. analysis of a Cosmos and the poisoning by mer- on commercial and scientific ana- Phosphates, analysis of natural, 209 219 on an analysis of, 254 160 volumetric determination of, ethyl ether, 46 Phosphorus, on the nature of white, Photographic image, nature of the Photography, recent discoveries in, 210 Pierre, M. I. analytical researches on the variations which the Piesse and Reveil, MM. des Odeurs, Piria, Signor, death of, 84 by carbonic oxide, 58 Popular scientific teaching, 278 iodide of, 155, 169, 295 Practical Chemistry, a Course of, Practice with Science: a series of Preyer, M. on the active principle Price, Dr. D. S. on the action of 308 Pumps, to thaw out frozen, 222 Pyrophosphodiamic acid, 283 QUEEN'S College, Belfast, 145 |