CHEMICAL NEWS, April 11, 19 i Atams, Electrons, and Valency. for sodium were 23'024, 23.086, 23.10. The author is studying the decomposition of NaN, and KN3 and intends to continue these researches on the revision of atomic weights of the metal of the alkalis and alkaline earths. Journal de Chimie Physique, 1918, xvi., 401. Oxidation of Nitric Oxide by Dry Air.-André Sanfourche. The reaction between nitric oxide and dry air takes place in two stages, with very different velocities; the first, which is extremely short, corresponds to the formation of nitrous anhydride N2O3, while the second and longer stage leads to the formation of peroxide N204. At the ordinary temperature the velocity of both reactions has been shown by the author and M. P. Jolibois (Comptes Rendus, 1919, clxviii., 235) to be not appreciably influenced by the proportion of air. The author has now studied the influence of temperatures lying between -50° and 525° upon the same velocity. The results show that the temperature does not appear to have any effect upon the very great velocity of the reaction 2NO+02=2N203, which is complete in a fraction of a second, but on the other hand it profoundly modifies the course of the reaction 2N203+02+2N2O4 (or 4NO2). This reaction, which is also very rapid below o°, is complete up to about 200°, but occurs more and more slowly, this difference being possibly connected with the dissociation of N2O4. Above 200° there is a tendency to establish the equilibrium 2N2O3+024NO2. The displacement of the equilibrium takes place from right to left as the temperature is raised from 200 to 600°. - Comptes Rendus, 1919, clxviii., 307. Precipitated Amorphous Silica.-P. Braesco.-Pre. cipitated and calcined silica has usually been known under the name "amorphous silica." The only reason for regarding it as amorphous is that no crystals of definite form can be distinguished, either with the naked eye or under the microscope. But it is well known that similar preci pitates, like so-called amorphous barium sulphate, are really crystallised, and the author has investigated the true nature of "amorphous" silica by determining some of its physical properties. Measurements of its dilatation were performed, using Chévenard's apparatus and starting either with silica obtained by the decomposition of sodium silicate with hydrochloric acid, or else with silica obtained by the decomposition of silicon fluoride with water. In both cases the results obtained were the same. When silica is precipitated, dehydrated, and heated only to 600° it behaves exactly like vitreous silica, and has the same low coefficient of dilatation. It is thus true amorphous silica. But when it is precipitated and calcined at a temperature above 1000° there is an abrupt change of dilata tion between 220° and 240°, and silica calcined above 1000° is not amorphous silica, but crystallised silica of the cristobalite variety.-Comptes Rendus, 1919, clxviii., 343. Action of Alkalis on Crucibles made of Alloys of Platinum and Gold.-Paul Nicolardot and Claude Chatelot. These experiments were performed in order to find out whether new platinum is less attacked than old platinum when alkalis are fused with it, and whether the presence of iridium increases or decreases its resistance The fusions were all carried out to the same alkalis. similarly, 5 grms. of alkali being used, and the process occupied ten minutes, the source of heat being a spirit lamp. The crucibles were first weighed, then the fusion was carried out, and they were then washed with water and dried. They were found to have lost weight, and their This black clean shining surface had been blackened. deposit disappears on treatment with hydrochloric acid. The loss of weight of metal is considerable, and is always New greater when potash is used than with soda. crucibles are more resistant than old ones, and the presence of iridium does not increase the resistance, but rather the reverse. The presence of copper does not seem to be as deleterious as that of iridium.-Bulletin de la Société Chimique de France, 1919, xxv.-xxvi., 4. 179 Determination of Zirconium.-Paul Nicolardot and Antoine Reglade.-The formation of a phosphate in an acid medium has been used by Hillebrand to analyse zircons, and it seemed to be of interest to find out whether the precipitation of zirconium is really complete in presence of iron, chromium, and aluminium. The reaction would be characteristic of zirconium, since bismuth, which is very rarely associated with it, is the only element which could be determined in these conditions. The authors have carried out a series of tests to determine the effect of the acidity of the solutions of foreign salts and of the time of contact with the reagents before filtration. The salt used was pure nitrate of zirconium, and the foreign salts added were those of iron, aluminium, and chromium. The results showed that ammonium phosphate in an acid medium (20 per cent at least of sulphuric acid) is a characteristic reagent for zirconium in presence of iron, aluminium, and chromium, and bismuth is the only other element which is precipitated in these conditions.Comptes Rendus, 1919, clxviii., 348. Cycle of Oxidation of Nitrogen Dioxide in Presence of Water.-André Sanfourche.-The reaction which is generally supposed to take place between nitrogen peroxide and water can be represented by the equation 3N204+2H2O=4HNO3+2NO. The study of the velocity of oxidation of nitrogen dioxide, however, suggests that nitrous anhydride may play some part in the reaction, and this hypothesis can be verified by bringing into intimate contact vapour of nitrogen peroxide mixed with an excess of air and water or more or less diluted nitric acid. The experiments show that in the oxidation of nitrogen dioxide in presence of water nitrous anhydride is the intermediate product and not nitrogen peroxide. Nitrous anhydride is oxidised by nitric acid of sufficient concentration with formation of nitrogen peroxide and water this reaction is limited by the inverse reaction. Thus there acid, and experiments show that this concentration is in must be equilibrium for a certain concentration of nitric the neighbourhood of 50 per cent.-Comptes Rendus, 1919, clxviii., 401. Substitutes for Platinum in Electrolytic Apparatus. Paul Nicolardot and Jean Boudet. - Metals or alloys which are to be used to replace platinum in electrolytic apparatus must be unalterable even in moist warm air containing sulphuretted hydrogen. They must be able to be washed with water and dried without change of weight, and must resist the action of pure nitric acid. They must remain unaltered during electrolysis in the liquids generally employed-sulphuric and dilute nitric acids, dilute ammonia, aqueous solutions of sodium sulphide and cyanide. They must also possess the mechanical qualities necessary to enable them to be worked up into the usual shapes of electrodes. Various commercial alloys have been investigated by the authors for the purpose, and they have found that the most suitable is an alloy of gold containing-gold, 920 parts; silver, 50 parts; copper, 30 parts. It is very resistant towards nitric acid. In the case of the anode the surface must be covered with a very thin layer of platinum (0.005 grm. per square cm.) by electrolysis, to protect it against oxidation. The alloy can be used as such for the cathode.-Bulletin de la Société Chimique de France, 1918, xxiii.-xxiv., 387. MISCELLANEOUS. Atoms, Electrons, and Valency.-With the more recent views of the disintegration of matter, chiefly the result of the discovery of radium, the electro-positive and negative character of the elements come into play. The constancy of mass and weight are involved in their disintegration, and a dual variable electric character might NEWS MEETINGS FOR THE WEEK. be ascribed to the elements. With regard to mass the | for the sterilisation of drinking water and the maintenance measure of which is weight, the force of gravity, there is of a wholesome atmosphere in factories, workshops, still needed an efficient theory of this force, and, admitting schools, theatres, barracks, hospitals, underground railthe disintegration of matter, such factors as atomic heat ways, and mines. For use in mines it may be of inestimand gas volumes are more the essential properties of the able service.--Bulletin de la Societé de l'Industrie Minérale, atoms. If the atomic weights are considered in relation Third Issue, 1918. to the periodic law, most attention has been given to the relationship existing in the several groups. The increase of atomic weight in the horizontial period may have some relation to valency, and in the latter half of the periodic table the halogens which, classed as heptads, are monovalent with the alkali metals in the first half, valency being MONDAY, a more complex function of the constitution of the elements. Taking the increase of atomic weight as affecting valency, in the periods and the group relationship as to weight, atomic volumes introduce the conception of space. The views of the disintegration of matter may be advanced not only by considering the radium elements but ionisation in liquids and the electric discharge in rarefied gases.-J. C. THOMLINSON. Geological Society.-At the Annual Meeting, held February 21, the following Medals and Awards were presented : Sir AUBREY STRAHAN, K.B.E.-The Wollaston Medal. TUESDAY, "Sub 14th.-Ceramic Society, 7. (In the Central Schools of FOR SALE. Miss GERTRUDE L. ELLES, SC.D.-The Murchison SARTORIUS BALANCE. In new condition. Medal. WILLIAM FRASER HUME, D.Sc.-The Lyell Medal. Whot offers ?-Address, "Sartorius," CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, E.C. 4. Major Sir DOUGLAS MAWSON, D.Sc.-The Bigsby Miscellaneous Medal. LABORATORY EQUIP. MENT, mostly Bottles, FOR SALE. What offers?-Write, ALEXANDER LOGIE DU TOIT, D.Sc.-Balance of the McMasters, 94, Knightsbridge, S.W. 1. Proceeds of the Wollaston Donation Fund. Mrs. ELEANOR M. REID, B.Sc.-Balance of the Proceeds BINOCULAR MICROSCOPE by Beck. All of the Murchison Geological Fund. Mr. JOHN PRINGLE.-Moiety of the Balance of the adjustments, Polarising Attachments, &c. Cost £80, including five Lenses, 1, 2/3, 4/10, 1/5, and 1/0. Also several Sets of 24 Slides, in neat boxes of four trays; also some Large SPECTROSCOPE, by Hilger, with Prism. In perfect con- horse MOTOR; speed, 1800 revs., 50 volts, campères. PATENTS AND DESIGNS ACTS, 1907-1914. The PHENOL PRODUCTS. he Proprietor of BRITISH LETTERS PATENT No. 9292 of 914 is prepared to Sell the Patent or to License British Manufacturers to Work under it. It relates to an Improved Method of Manufacturing Condensation Products of Phenol and Substances containing the Methylene Radical. Address-BOULT, WADE, and TENNANT, PATENTS AND DESIGNS ACTS, 1907-1914. The Proprietors of BRITISH LETTERS PATENT No. 9292 of 1914 are prepared to Sell the Patent or to License British Manufacturers to work under i. It relates to the reaction together of an Anhydrous Methylene body, a Phenolic body, and a Phenolic Compound having an Alkylated Hydroxyl Group in its Molecule. Oxygen a Revolutioniser of Industry.-(From the Technical Supplement, Feb. 18).-Due to the rapid growth of the nitrate industry based on the fixation of atmospheric nitrogen, the cost of oxygen has fallen enormously since the outbreak of the war. This great achievement in science, whereby oxygen is made a by-product of an important manufacture, is likely to work a revolution in industry. The uses of oxygen, when cheaply produced, are almost endless. Gas manufacturers will not be slow to utilise it to increase the light of their burners where a strong illumination is required; for that purpose new forms of burners will be called for. In metallurgical operations a small percentage of oxygen blown into the furnaces will raise the temperature considerably. In such cases it will allow inferior and cheaper qualities of coal to be used. Carbide of calcium will be produced in the blast-furnace by a purely thermic method. Alumina will be reduced by carbon. Auriferous quartz will be melted. The glass industry will be revolutionised by the easy fusing of all forms of quartz. A new chemistry, viz., that of the F. WIGGINS & SONS, 102/3/4 Minories, London, E. electric furnace, will be created. The manufacture of sulphuric acid will be much accelerated by the powerful oxidation of sulphurous acid. The production of ozone, or electrified oxygen, opens up numerous vistas, notably Address-BOULT, WADE, and TENNANT, MICA. MICA MERCHANTS, Telephone No. 2248 Avenue. Manufacturers of dica Goods for Electrical and ALL purposes. Property of Chemical Laboratory of Harvard College THE CHEMICAL NEWS AND JOURNAL OF PHYSICAL SCIENCE (WITH WHICH IS INCORPORATED THE "CHEMICAL GAZETTE ""). Established in the Year 1859. Published Weekly. Annual Subscription. free by post £1 Entered at the New York Post Office as Second Class Mail Matter. Transmissible through the Post-United Kingdom, at Newspaper rate; Canada and Newfoundland, at Magazine rate. Vol 118.-No. 3079 [Copyright Thursday, April 17, 1919 reserved. Registered as [PRICE 4d. a Newspaper. Post FREE 41d. HEMIST.-Wanted for Factory Testing work, qualified Analytical Chemist.-Apply, giving full particulars, to Manager, The Imperial Tobacco Co., Ltd., Dingley Road, City Road, E C. 1. 189 Discharged Soldier desires Situation 190 192 in Chemical Laboratory. Specially qualified in Metallurgical Analysis of Rare Metals.-Address, D. S, CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, E.C.4. CAPPER PASS & SON, Lim., Enterprising Assistant Chemist (21) desires a BEDMINSTER SMELTING WORKS BRISTOL, are buyers of LEAD ASHES, SULPHATE OF LEAD, a Laboratory or Works. Formerly Assistant Chemist, Directorate of Chemical Inspection, and capable of undertaking any Inorganic Analyses. Would commence a moderate salary. - Address, Mr. W. G. Richards, 7, Sivell Place, Heavitree, Exeter. LEAD SLAGS, ANTIMONIAL LEAD, Chemist (20), Inter. 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CHEMICAL APPARATUS Pure Chemicals for Research Work. JOHN J. CRIFFIN & SONS, LTD., KINGSWAY, LONDON, W.O WHATMAN'S free QUALITY TELLS. April 17, 1919 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. CHEMICAL NEWS Physical Chemistry and its bearing on Chemical Industries 181 amount of silica is unusually small, as might possibly be expected from the crystalline structure of the material. 5. From Bertram, Iowa. This belongs to the Niagara formation which lies between Mount Vernon and Cedar Rapids. The rock is grey in colour with numerous small light coloured crystals disseminated through the msss. Some analytical data had been found which seemed to indicate that the magnesium content of the rock was in excess of the calcium. Our analysis was made with a view to determine whether this was really the case. Two concordant results obtained are as follows: PHYSICAL CHEMISTRY AND ITS BEARING ON THE CHEMICAL AND ALLIED INDUSTRIES.* By Prof. JAMES C. PHILIP, O.B.E., M.A., Ph.D., D.Sc. (Concluded from p. 173). THE validity of the foregoing equation being thus established it may be employed to calculate for even temperatures and a number of pressures the maximum quantities of ammonia obtainable by the interaction of nitrogen and hydrogen. These figures, constituting a summary of the influence of temperature and pressure on the ammonia equilibrium, are presented in the following table [valid for I vol. nitrogen +3 vols. bydrogen] : Total The specimen contains a sufficiently high percentage of magnesium to class the rock as a fairly typical dolomite. 4. The white crystals encrusting the specimen : Per cent. From the physico-chemical standpoint then the conditions which affect the position of the ammonia equili brium are thoroughly understood, and their influence can be definitely formulated. Plainly, the highest percentage conversion of nitrogen and hydrogen into ammonia is to be secured by working at a high pressure and a low temperature. There is, however, a limit to the pressure under which a large scale process can be carried out conveniently and safely, and the pressure employed in practice is not above 150-200 atmospheres. The use of high pressures such as those just quoted leads not only to a favourable displacement of the equilibrium, but also to an increased rate of approach to the equilibrium position. • Cantor Lecture (I.). Delivered before the Royal Society of Arts, December 2, 1918. From the Proceedings of the Royal Society of Arts xvi., No. 3450. |