May 2, 1919 Before the meeting the Department of Glass Technology was thrown open to members of the Society, many interesting and instructive operations being carried out. Mr. J. B. Davidson, M.Sc., F.I.C., showed the casting of a 2 cwt. Glass Pot. After the visit of inspection, members of the Society had the valuable opportunity of seeing the Vacuum Casting of a large Glass Pot. The pot when finished was some 38" in diameter, and of the hooded variety. The demonstration was carried out by Mr. B. J. Allen. In the evening the Society held their first annual dinner in the Grand Hotel; the chief guest was the past President, Mr. W. F. J. Wood, C.B.E., B.Sc. The other guests present included Dr. Ripper (Vice-Chancellor of Sheffield University), Sir Frank Heath, Dr. F. E. Bradley, Mr. A. P. Trotter, Mr. W. Gibbons, Mr. P. V. B. Tippetts, Mr. A. P. M. Fleming, Mr. T. Mortimer Sparks (Commercial Editor of the Sheffield Daily Telegraph), Mr. R. Ainger (Commercial Editor of the Sheffield Independent). The next meeting of the Society will be held in London on May 21, when it is hoped that Dr. Walter Rosenhain, F.R.S., will read a paper on "Refractories Research" carried out at the National Physical Laboratory. On the morning of the meeting members will be given the opportunity to visit the National Physical Laboratory. NOTES. OSMOTIC PRESSURE AND PREPARED FOODS. - In keeping preserved foods enclosed in skin, osmotic pressure on the membrane of even slightly salt solutions will tend to prevention of putrefaction. An attending phenomena that such is the case is that during sudden fall of temperature there is a distinct exudation of water.-J. C. THOMLINSON, B.Sc. OSMOSIS AND EMULSIONS.-Osmotic pressure in the presence of emulsions in organic semi-solutions and in pastes gives rise to phenomena, two of which may be described. In the first, solutions of a colloidal character evaporated in vacuo may, after standing for some time, contract to a considerable extent, in which neither contraction on cooling or normal evaporation can be advanced as the immediate causes. In the second, organic pastes contained in membranes, on cooling the external surroundings, transfuse water by osmosis in quantity, the liquid exuded bearing a considerable ratio to the paste left.-J. C. THOMLINSON, B.Sc. A NEW Association called the Technical Inspection Association has recently been formed, which should appeal very strongly to many technical men throughout the Empire who are in any way interested in inspection work. It is the outcome of the Ministry of Munitions Inspection Department, and has been formed for two main purposes :-(1). To maintain intercourse and promote mutual assistance among its members. (2). To conserve and co-ordinate for the national use the experience brought together by the War and generally to develop the progress and standardisation of inspection in the engineering, chemical, and allied industries. Owing to the stoppage of war work the services of large numbers of men, most of whom possess high technical qualifications, and who have spent several years on the inspection of Government contracts, are now available. A list of such members is held the honorary secretaries, who will be glad to supply particulars to any who may be interested." THE Hardware and Engineering Supplies Co., Ltd., 16, Water Lane, Great Tower Street, E.C. 3, are manu. facturing amber glues in liquid and jelly form, as used by ply woo manufacturers, aircraft and cabinet manufacturers, box makers, and bookbinders, superstarch for launderers in liquid form, and soft soaps and soap bases, and desire publications bearing on these industries. FREDERICK COPE, Consulting Engineer, Southgate Chambers, Wakefield, desires information ee the most efficient plant and up-to-date methods in connection with Also the most modern process for rag brickmaking. carbonising. THE Board of Trade announce that the Fuel Order, 1918, which controls the sale of wood for fuel, will cease to have effect as from April 30. IT is notified that Messrs. F. Bunn, King's Lynn, G. V. Sedgwick, Middlesex, and B. C. Wilkinson, Reigate, nominated under the 8th Section of the Weights and Measures Act, 1904, have passed the examination provided for under that Section. A CONSIDERABLE number of merchants and business representatives who formerly lived in Russia are at the present time in the United Kingdom owing to the actions of the Bolsheviks. As a considerable part of the former Russian Empire is now available for trade, it may be that firms in this country would be glad to take advantage of the present exceptional opportunity of obtaining the services of these men, who are especially well qualified to open up trade with Russia. The Department of Overseas Trade would be glad to hear from any firm that desires to be brought into touch with the persons referred to, either immediately or later on, when trading in a more general way can be conducted with Russia. Enquiries should be addressed to the Russian and Scandinavian Section, Sunderland House, Curzon Street, Mayfair, W. 1. AMONGST the questions which the closing months of the war have brought to everyone's notice there is none of wider interest than domestic service. For although it is the custom to joke over "the servant problem," it comes home vividly to every man and woman in the kingdom. Scoffers may laugh at including elementary science in a cook's training, but how else is she to understand and remember why cold water removes the smell of onions while hot water fixes it; why certain foods should be put down in boiling water while others need cold water; why the contents of some saucepans are to be kept covered and others not? In every department of work the more thoroughly you understand the reason for your routine actions the more interesting they become. For that reason it is always well, where possible, to follow up orders with a brief reason for them-it also fixes the order in the maid's memory and prevents her thinking in some cases that it is purely arbitrary, if it seems at first sight slightly more troublesome than her old method. NOTES FROM FOREIGN SOURCES. Yellow Cuprous Oxide.-L. Moser. - The best way to prepare yellow cuprous oxide is by the reduction of Cu" ions in presence of OH' ions by means of hydroxyl. amine hydrochloride, and the electrolytic method, using a pure copper anode and alkali sulphate as electrolyte. The light yellow product which is first precipitated is very probably cuprous hydroxide, which spontaneously gives up water at a low temperature and is converted into the reddish yellow hydrated cuprous oxide which is amorphous. The dry yellow cuprous oxide is quite stable in air, but it shows a tendency to pass very slowly into the crystalline form. This very slow process can be hastened by heating the amorphous product in absence of air. The yellow cuprous oxide must thus be regarded as the primary metastable form which shows a tendency to pass into the metastable red crystalline modification.-Zeit. Anorg. Chemie, 1919, cv., 112. A very Sensitive Reaction of Copper. Application to the Analysis of Ash and Arable Soils.-L. Maquenne and E. Demoussy.—When a hydrochloric acid solution of an ash, sufficiently concentrated and carefully freed from iron and manganese, is treated with potassium ferrocyanide, ordinarily the liquid assumes a yellowish pink tint, indicating the presence of copper. But in most cases the coloration is not stable; it rapidly fades, giving place to a turbidity which on standing or centrifugation is resolved into a blackish precipitate tinged with brown or blue, as if the solution still contained iron. The cause of this anomaly appears to be the presence of zinc which is known to accompany copper in the organs of plants. If ferrocyanide is added to a very dilute cupric solution acidified with hydrochloric acid and containing varying proportions of zinc sulphate, the phenomenon can be reproduced, and when the amount of zinc is double that of the copper a blue mass can be separated by centrifuga. tion. The blue coloration attains its maximum of intenslty and purity when the zinc is four or five times as abundant as the copper, becoming paler as the proportion is increased. This is one of the most sensitive reactions of copper, and it is only necessary for the solution to be free from nitric acid and iron. To apply the method in practice the ash is heated with sulphuric acid in a quartz capsule, the particles of silica and calcium sulphate are separated by centrifugation and the liquid is electrolysed. After twelve hours the cathode is washed with warm nitric acid and water, the liquid is evaporated, the residue calcined and taken up with hydrochloric acid. Then sulphate of zinc (0.25 mg., .., 2 drops of a solution containing 1104 grms. per cent) and a drop of 10 per cent potassium ferrocyanide are added. If copper is abundant, in which case it would have been visible on the cathode at the end of the electrolysis, a pink coloration, which soon turns blue, appears. If the amount of copper is less than oor mg. the blue coloration appears after some minutes and the depth of the coloration of the precipitate obtained by centrifugation gives an indication of the amount of copper present.-Comptes Rendus, 1919, clxviii., 489. Method of Treating Beryl for the Extraction of Glucina.-H. Copaux.-Beryl usually possesses a composition very close to that corresponding to the formula Al2O3.6SiO3.3 Beo, i.e., 67 per cent of silica, 19 per cent of alumina, and 14 per cent of glucina. It is very refractory towards acids, but is acted upon by caustic alkalis, which at a temperature of about 400° transform it into a silico-aluminate of glucina and alkali, which is then readily attacked by acids. This method of opening up the mineral has the disadvantage of necessitating the elimination of the 67 per cent of silica which is present in the gelatinous form. The author has discovered a method of treatment of beryl which depends upon the action of sodium fluosilicate at a temperature of about 850°. Sodium Aluosilicate Na2SiF6 is a white crystalline powder which is decomposed by heat at about 750° giving sodium Aluoride and silicon fluoride, a very active gas which attacks the glucina giving glucinum fluoride 2BeO+SiF, SiO2+2BeF2. The latter then forms sodium fluoglucinate with I litre; 300 cc. are then evaporated in a platinum crucible with excess of sulphuric acid till white fumes are evolved. The mass is then taken up with water and precipitated with ammonia. If iron is present in considerable amount the precipitate is dissolved in acetic acid, and the iron is removed by B-nitroso-naphthol. The filtered liquid is then reprecipitated with boiling ammonia, and the new precipitate, which consists of glucina, a little alumina and silica, is washed, dried, and weighed and then treated with a few drops of hydrofluoric and silicic acids to drive off the silica. After evaporation the alumina is removed by fusing the residue with three times its weight of sodium carbonate, extracting the sodium aluminate with water, and finally weighing the insoluble residue of glucina.Comptes Rendus, 1919, clxviii., 610. Reagent for and Method of Determining Ozone. Louis Benoist.-As the phenomenon of fluorescence can be detected optically with great accuracy the author sug gests a method of determining ozone based upon its action on fluorescine. If some cubic centimetres of a very dilute solution of fluorescine are introduced into a flask of slightly ozonised oxygen, after a few seconds the fluorescence absolutely disappears and the reagent is decolorised. If the solution is more concentrated the fluorescence disappears, but the colour of the reagent is only reduced to pale yellow. Pure oxygen has no effect. The traces of nitrous fumes contained in the air have no effect upon this new reagent, but chlorine does decompose fluorescine. On the other hand, its presence is very easily detected by other means and the gas can then be eliminated. The same applies to carbon dioxide, which destroys fluorescence when concentrated. The reaction appears to take place between two molecules of ozone and one molecule of fluorescine, the ratio of the weights being 96 0:29. The least weight of ozone detectable by this method would thus be one-third of the least weight of fluorescine which would give an appreciable fluorescence. A Nernst or other lamp giving a very white light is enclosed in a dark box having two contiguous openings in the lid, in which are two colourless glass tubes; one contains the solution of fluorescine and the other control tube contains distilled water only. The caustic by refraction is observed in each tube, the one containing fluorescine exhibiting a distinct fluorescence. This method of determining ozone is very sensitive and possesses the advantage of requiring only one solution. The product of the reaction appears to be easily destroyed by beat, but the original fluorescine is not reformed; the addition of ammonia does not cause the reappearance of the fluorescence, and the final weight of the product after drying is only a very little less than that of the original substance. The product without being explosive appears to be in some way related to the ozonides.-Comptes Rendus, 1919, clxviii., 612. 332 NOTES AND QUERIES. the sodium Aluoride 2BeFa+4NaF-2BeF Na2, which is soluble in water. The alumina by an analogous reaction is transformed into sodium fluo-aluminate, which is hardly soluble in water. Thus when the product of the reaction is taken up with To boiling water all the glucina goes into solution. purify the product the aqueous solution is treated with a small excess of boiling caustic soda, which precipitates simultaneously glucina, alumina, and silica, carrying analysis of citrate of lime. (Reply to A. C.). down fluorine. The precipitate is redissolved in sulphuric acid, concentrated to expel the fluorine, and then the glucina is erystallised as sulphate Be80,+4.0, which is not isomorphic with either aluminium or ferrie sulphate, which may be present in small quantities. By this method about nine-tenths of the glueina in the mineral is recovered. To determine the glucina in beryl 5 grms. of the finely powdered mineral are mixed with 20 grms. of sodium Auosilicate and heated for thirty to forty minutes to 850° in a graphite crucible. After cooling the powdered mass is taken up three times with boiling water and the aqueous liquid after filtration is made up to Our Notes and Queries column was opened for the purpose of giving and obtaining information likely to be of use to our readers generally. We cannot undenake to let this column be the means of transmitting merely private information, or such trade notices as should legitimately come in the advertisement columns. Particulars and references are desired of the Ogston method for the MEETINGS FOR THE WEEK. MONDAY, sth.-Royal Institution, 5. (@eneral Meeting). People of Wales and Ireland," by Pref. A. Keith. SATURDAY, Hele-Shaw. "Chinese Turkistan-Past and Present," by Sir George Macartney, K.C.I.E. hot.-Royal Institution, 3. "Chapters in the Psychology of Industry," by Prof. H. S. Foxwell. JUN 171913 UNIV. OF THE CHEMICAL NEWS AND JOURNAL OF PHYSICAL SCIENCE (WITH WHICH IS INCORPORATED THE "CHEMICAL GAZETTE"). Published Weekly. Annual Subscription, free by post, 1. Entered at the New York Post Office as Second Class Mail Matter. Gold and Silver Assaying, required at once. Permanent position; good prospects; Birmingham. State age, experience, and salary required.-Address, "A. 25," CHEMICAL NEWs Office, 16, Newcastle Street, Farringdon Street, London, E.C. 4. Chemist desires Employment in London. CAPPER PASS & SON, Lim., years Organic Research Work. Would be content to start as Assistant BEDMINSTER SMELTING WORKS BRISTOL, are buyers of LEAD ASHES, SULPHATE OF LEAD, NEW TYPE Particularsfrom OZONAIR LIMITED, 96, Victoria Street, London, S.W.L FINE CHEMICALS. A. BOAKE, ROBERTS & Co. LTD., STRATFORD, LONDON, E. 15. During War, Chief Chemist in a Canadian T.N.T. plant. Two any branch of Chemistry.-Address, S. L., CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, E.C.4. Chemist, with four years' training at Finsbury Technical College, having taken active service immediately upon completion of course, is now demobilised and seeks Engagement. -Address, A. E. G., 21, Chestnut Road, West Norwood, S.E. Demobilised Soldier (21), Inter. B.Sc. (Lond.), two years' experience as Laboratory Demonstrator at a Secondary School, desires Position in Works Laboratory, preferably in Midlands or London district.-Address, A. E. B., 13, Midland Road, Rushden, Northants. Metallurgical Chemist (33) desires change. Non-ferrous Analysis, Physical Testing, and Microscopy. Sixteen years' experience, partly in Public Analyst's Laboratory and partly in Metal Refinery -Address, " M 33," CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, E.C. 4 PUPIL ASSISTANT.--A London Public Analyst, with a large and varied practice, has a vacancy for a Pupil Assistant. No premium.—Apply, “ Analyst," 2, Queen Anne's Grove, London, W. 4. wo Analytical Chemists are required for a large Testing Laboratory. Commencing salary £200 per annum. It is desired that applicants should have had at least two years' experience in the Laboratories of Steel or other Metallurg cal Works. Preference gives to those who have fought in the War. -Address, "Analytical," CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, E.C. 4. T. TYRER & CO., Ltd. Stirling Chemical Works, STRATFORD, LONDON, E. CHEMICALS for Analysis, Research, and Technical purposes TECHNICAL experimÉNTS carried out on a MANUFACTURING SCALE. Inquiries solicited from INVENTORS ard FATENTEES (especial.y Foreign) under the New Act, 1906, CHEMICAL APPARATUS Pure Chemicals for Research Work. JOHN J. GRIFFIN & SONS, LTD., KINGSWAY, LONDON, W.C WHATMAN'S May 9, 1919 QUALITY TELLS. IN N experiments, the quality of every detail tells. Filter Papers and Extraction Thimbles are important, therefore get the best-get "Genuine Whatman," manufactured by W. & R. Balston, Ltd., Paper Makers in Britain for over 150 years. Genuine Whatman Filter Papers are made in all grades- Genuine Whatman Extraction Thimbles are Fat-Free and Seamless. THE apparatus is shown in Fig. 1. The five-litre bottles B contained a supersaturated solution of sodium sulphide. Hydrogen sulphide was generated in this bottle by slowly dropping in I: I hydrochloric acid contained in the bottle A by means of a syphon and stopcock. It was purified from hydrochloric acid gas by passing through the sodium sulphide wash bottles D and E. After passing through the drying tower F, which contained calcium chloride, the gas was reduced to o° C. by passing through the coil condenser G, which was completely surrounded by a cooling mixture. After cooling to o° C. it entered the reaction chamber K, which consisted of a 500 cc. separatory funnel crucible also was jacketed and surrounded by a freezing mixture. The advantages of this apparatus deserve mention. The gas was thoroughly cooled to o° C. before entering the reaction chamber by passing through the long coil condenser surrounded by ice and water. The rate of flow was not great, owing to a fine jet between B and D, but was uniform. The reaction chamber was at o° C. by being completely surrounded by the cooling mixture. After extraction, the carbon disulphide and that part of the precipitate that had actually been extracted could be drawn away. There was always a small amount of precipitate which remained in a fine suspension in the water above the carbon disulphide which was not extracted, but this never reached the filter. Moreover, the difficulty of filtering two immiscible liquids was overcome. The filter being jacketed with the freezing mixture insured its temperature to be at o° C., so that at no stage during the operation was the precipitate subjected to any temperature other than o° C. Using this apparatus, a final series of experiments was carried out which served as a check on the results previously given. The details of procedure may be described as follows:-A sample of tellurous acid, acidified with hydrochloric acid representing approximately 0.2500 grm. of tellurium, was placed in this apparatus along with contained in an asbestos-covered iron box with the stem and stopcock protruding through the bottom of the box. The box was completely filled with a cooling mixture for one hour before and during use, thus insuring that all parts of the reaction chamber with which the precipitate might come in contact would be at o° C. Precipitations were carried out in the presence of 100 cc. of carbon disulphide, into which the precipitate was forced as formed by a constant whirling motion of the box during the introduction of hydrogen sulphide gas. After allowing the precipitate to stand in contact with the carbon disulphide the desired length of time, the carbon disulphide and the precipitate which had collected in it were drawn off through the stopcock on a large Gooch filter. The Gooch Abstract of a part of a thesis submitted to the Graduate School of the University of Wisconsin in partial fulfilment of the require ments for the degree of Doctor of Philosophy. From the Journal of the American Chemical Society, xli., No. 3. 100 cc. of carbon disulphide. Hydrogen sulphide was passed in for three minutes. During this time the reaction chamber was shaken to transfer the precipitate down into the carbon disulphide as formed. At the end of nine minutes the carbon disulphide and precipitate contained in it were passed rapidly through a suction filter consisting of a Gooch crucible fitted with a small disc of filter paper. One minute was thus allowed for the filtration. The suction of the precipitate was continued for ten minutes to remove the last traces of carbon disulphide. The precipitate thus collected was removed from the paper, placed in a P2O5 desiccator, and evacuated overnight. A sample of the precipitate was then weighed carefully, oxidised with fuming nitric acid in the cold, and the nitric acid removed by careful evaporation at 80° C. The residue was taken up in 10 per cent hydrochloric acid and the exact tellurium content determined. A short table of results follows: |