152 Viscosities and Compressibilities of Liquids at High Pressure housewife. From the dried meat, savory stews and hashes are made, while the vegetables which may be in. corporated with the meat have as fine a flavour as if they had only recently come from the garden. It would be possible by means of this process to dry beef in vacuum ovens in parts of the earth where cattle may be raised very cheaply, as in Argentina, and to transport the dried product for many thousands of miles at very low freight cost. As canned fruits contain considerable moisture and are placed in metal containers, the advantages of the vacuum-dried products become manifest, according to the view of Dr. Falk. "Transportation," said he, " has always been a question of vital importance. Ships and other common carriers are always at a premium, and again certain kinds of food require special equipment, such as cold storage. For example, the plentiful supply of sheep in New Zealand might benefit the rest of the world to a greater extent if more transportation facilities were available." Dr. Falk said that usually sun-dried meats and other foods were discoloured and that their nutritive values were impaired. While even with fairly good methods of dehydration it would have been found necessary to use bleaching agents, a recourse which was not required, according to the process developed at the Harriman laboratories. The incentive to develop this method of preservation for food products was given early in Nov., 1917, by Col. John R. Murlin, in charge of the Division of Food and Nutrition of the U.S. Army, and was developed by Dr. Falk, Dr. Edward M. Frankel, and Prof. Ralph H. McKee. "In the dehydration of meats," said Dr. Falk, "the temperature must be kept below the point at which the proteins coagulate, for if there is too low a temperature the process of dehydration will be unnecessarily prolonged, with the result that often spoilage will occur and the overhead cost will be greatly increased. It is possible to solve this problem of dehydration by the use of a suitable vacuum drier in which the meat or other food product is introduced, in pieces of suitable size, and kept in the vacuum at a temperature which is below that of cooking or which makes no appreciable change." Dr. Falk said that a large variety of foods had been dehydrated by the vacuum method and that a number of others will probably be subjected in time to the same process. The mechanism used is not complicated and can be easily installed at remote places. "In considering food preservation methods in general, it may be stated," he said, "that such methods will come into use more and more." The Government estimated that 50 per cent of the fruits and vegetables grown in this country never reach the consumer as a result of poor transportation facilities, irregularities in marketing, or other causes. At the same time, greatly because of recent work on such questions as food hormones, the tendency is to use fresh foods wherever possible. The newer dehydration processes approach more nearly the requisite standards of fresh foods than do the older methods of preservation. The whole question is in a state of development. Dehydra: tion offers the most promising outlook for the future. Air dehydration marks a great advance over the older methods | of food preservation, and it would appear that vacuum dehydration possesses in its turn advantages over air debydration (Am. Chem. Soc. News Service, No. 249). -Fournal of the Franklin Institute, January, 1920. GERMAN POTASH FOR AMERICA.-It is understood that the negotiations for the sale of large quantities of potash to America, which are being conducted by the Potash Syndicate, are nearing conclusion. The deal has still to be approved by the General Directorate of the Potash Syndicate, which is holding a meeting within the next few days. The Vossische Zeitung says that the quantities involved will cover half of America's total requirements.Reuter's Trade Service. CHEMICAL NEWS, PROCEEDINGS OF SOCIETIES. ROYAL SOCIETY. Ordinary Meeting, February 26, 1920. Sir J. J. THOMSON, O.M., President, in the Chair. THE following papers were read :— "Some Measurements of Atmospheric Turbulence." By L. F. RICHARDSON. The eddy-shearing stress on the ground is deduced from pilot balloon observations. Values on land in any consistent dynamical units are found to range from 0.0007 to 0007 times the value of mp where m is the mean the density. momentum per volume up to a height of 2 km. and p is Evidence is given to show that the eddy viscosity across the wind at Lindenberg increases with height, and, except near the ground, is much greater than the eddy viscosity along the wind. In Parts IV. and V. the spreading of a lamina of smoke is considered. Osborne Reynolds' eddy stresses are studied. For one occasion an attempt was made to measure simultaneously all six components of stress, by observing the motion of thistledown. The three direct stresses are easily measured. Not so the shearing stresses; however, one was found to be 24 times its probable error. numerical values derived from scattering. The "turbulivity" is estimated from the rising cumuli in calm weather and found to be 106, applicable only in the sense of friction. Thus the whole range of & observed in the free atmosphere was from seven to a million, in contrast with o.2 in perfectly still air. The eddie stresses observed have ranged in absolute value from 0.004 to 100 dynes cm-2. "On the Viscosities and Compressibilities of Liquids at High Pressure." By J. H. HYDE. In the first place experiments were made to determine the change in the value of the kinematical viscosity (n/p) of the various oils, and after this investigation was completed apparatus was designed for the determination of the change in density with pressure. The apparatus used for the determination of the kinematical viscosity consisted essentially of a system of two horizontal (the upper one of capillary dimensions) and two vertical tubes forming a closed circuit of liquor under pressure, the lower half of the circuit containing mercury and the upper half the liquid under test. One end of the tubular frame rests on a horizontal knife edge, and the frame is supported in a horizontal position by a spiral spring. On the mercury being displaced by a given amount, flow will take place round the circuit owing to the difference of head, and it is evident that if the spring be so designed that its range of extension is equal to the rate of change of head of the mercury, flow of the liquid under test will take place through the capillary tube under a constant pressure-difference and at a velocity which can be calculated from the rate of extension of the spring. In this way all the data required for the determination of the absolute kinematic viscosity of the fluid were determined. The determinations of the variation in density under pressure were made by measuring the decrease in volume of known quantity of the liquid enclosed in a steel cylinder sealed at one end and closed at the other by a long steel plunger. The cylinder and plunger were enclosed in a pressure vessel, and the motion of the plunger for any particular pressure was measured. The density was calculated from the decrease in the volume thus measured. From the values of the density (p) and those of the kinematical viscosity (n/p) obtained for the oils, the values of the absolute viscosity (n) were calculated. The results | fused silica, it having been found possible to prepare show that the absolute viscosity of all the oils tested in creases considerably with pressure. "The Capacity Coefficients of Spherical Conductors." By A. RUSSELL. It is proved that the capacity coefficient of a spherical conductor equals its radius, together with the capacity of the condenser formed by the spherical surface on the one side and the images in it of all external objects connected in parallel on the other side. This theorem leads at once to relations between the capacity coefficients of a system of two spheres and the capacities of certain spherical condensers which lessens very appreciably the labour involved in computing the values of these coefficients which are required in practical work. The mutual coefficient also is given in terms of the capacity of a spherical condenser, and other relations between the various capacities used by engineers and physicists are proved. Finally, a method of finding the approximate value of the capacity between a sphere and distant large conductors is given. "On the Refraction and Dispersion of Carbon Dioxide, Carbon Monoxide, and Methane." By C. CUTHBERTSON, F.R.S., and MAUDE Cuthbertson. The refractivity of the above-named gases have been measured at eight points in the visible spectrum between XX6708-4800. The work was undertaken with the object of ascertaining the refractive power of the carbon atom, on the assump tion of the validity of the additive law. By deducting the refractivity of the oxygen or hydrogen atoms from that of the carbon compound values are obtained from which the refractivity of carbon can be expressed in the form There are thus wide differences, not only between the quotients, which give the refractivity, but between the numerators, which should be proportionaal to the number of "dispersion electrons," and the denominators, which give the squares of the hypothetical free frequencies. The result affords a further proof that the "additive law" is untrustworthy except as a rough guide. "The Phenomena of Rupture and Flow in Solids." By A. A. GRIFFITH. Difficulties which had been experienced in predicting the fracture of machine parts under certain types of loading suggested the desirability of a fundamental inquiry into the mechanism of rupture. A theoretical criterion of the rupture of an elastic solid, based on the "theorem of minimum energy," is enunciated in the paper. This has been shown experimentally to be true in the case of a glass plate which contains a crack when unstrained. The calculation involves the surface tension of the material. In the experiments the maximum stress in the glass was estimated to be more than ten times the normal tenacity of the material. It is shown that this result is incompatible with the general criterion of rupture unless the material is weakened by discontinuities of flaws whose dimensions are at least of the order ten thousand times the molecular spacing. Evidence is adduced to show that the strength of other substances, including metals and liquids, is governed by similar considerations, and that an enormous increase in the tenacity of materials would be possible if the flaws could be eliminated. Experiments are described showing how the elimination may be performed in the case of glass and samples of these materials with nearly fifty times their normal tenacity. The strong phase of these materials is, hours to the normal modification. however, unstable, and changes spontaneously in a few the mechanical properties of materials, including those It is shown that many of the phenomena associated with described in the present paper, are capable of explanation attraction is a function of the relative orientation of the in general terms if it be supposed that intermolecular attracting molecules. Some consequences of this theory are discussed in the paper. bearing of the work on engineering practice. The paper concludes with a short discussion of the THE INSTITUTE OF METALS. Annual General Meeting, March 11, 1920. THE following is a summary of the Fifth Report to the Corrosion Committee, presented by Guy D. Bengough, M.A., D.Sc., R. M. Jones, M.Sc., and Ruth Pirret, D.Sc. "The Action on Aluminium of Hard Industrial Waters." By RICHARD SELIGMAN, Ph. Nat. D., Member, and PERCY WILLIAMS, B.Sc., Member (London). The authors first describe in detail the various forms of corrosion which aluminium exposed to the attack of hard industrial waters undergoes, and differentiate between superficial attack or "etching" and localised deep attack or "pitting." They point out that while etching is of no practical importance, pitting is one of the greatest diffi. culties the aluminium industry has to contend with. They discuss the various hypotheses extant by which the in. ception of corrosion is sought to be explained and show that these all entail the presence of oxygen. Experiments are described which show that in the absence of oxygen neither pitting nor etching occur even with seawater. Other factors which might determine whether "etching" or "pitting" occurs are cited and discussed. These are "The Presence of Impurities," "Local Physical Differences in the Metal," "The Composition of the Water," and Mechanical Imperfections in the Metal." The authors conclude that the composition of the water and mechanical imperfections in the metal are responsible for pitting, which only occurs when the water contains simultaneously chlorides and bicarbonates. The roll of mechanical imperfections is to facilitate the retention of hydrogen peroxide which is produced during corrosion and which in its turn promotes corrosion. In the second part of the paper a number of methods for preventing corrosion of aluminium by hard industrial waters are discussed. A bibliography of papers dealing with the subject is appended. "The Art of Casting in High Tensile Brass." By NEIL J. MACLEAN (Glasgow). "Manganese Bronze" castings as supplied by different makers having proved unreliable and unsatisfactory, a series of experiments was carried out with a view to obtaining castings made in sand moulds (unchilled) having a guaranteed strength of not less than 20 tons per square inch, as shown by test bars produced under the same conditions as the castings themselves. As a result of these experiments a copper zinc alloy was chosen containing 3 per cent of nickel and 2 per cent of iron, with a small quantity of manganese and phosphor tin. Special precautions were taken to accurately weigh the charge and to control the pouring temperature within narrow limits. A hardener of copper-nickel-iron was made up and finely granulated by blowing the molten metal into a tank of water. Special attention was paid to keeping the zinc content constant; ingots were analysed after first melting and the zinc corrected when making up the final charge. The alloy finally decided upon was made up of scrap, new metal, and hardener, with the addition of zinc to correct for loss in previous melting. By this accurate weighing of the charge, control of pouring temperature, correction of zinc, and use of special hardener, castings were obtained having strength properties 50 per cent better than gun-metal and at a cheaper price. "The Removal of Internal Stress in 70: 30 Brass by Low Temperature Annealing." By H. MOORE, O.B.E., B.Sc., F.I.C., and S. BECKINSALE, B.Sc., A.I.C. (London). The authors have carried out a series of experiments to determine the temperature range within which internal stress may be removed from cold worked 70: 30 brass without serious reduction of hardness. Cups spun from sheet and initially in a state of high internal stress were annealed at temperatures ranging from 200° to 325° C. for periods of one minute to 120 hours; they were then stressed brass to crack. Samples of cold-rolled strip of Brinell hardness 90, 120, 165, and 200 were annealed together with the spun cups. The hardness of the strips was determined before and after annealing. stress was removed from spun cups in five hours at 250° C., one hour at 275° C., twenty minutes at 300° C., or five minutes at 325° C. Strip of initial hardness of 200 was appreciably softened by each of these treatments, but the hardnesses not exceeding 120 were not reduced at temperatures up to 300° C. Strips of initial hardness of 165 began to soften slightly in two hours at 275° C., or twenty minutes at 300° C. The hardness of fully annealed 70: 30 brass is about 50 to 60, and a hardness exceeding 165 is rarely if ever required in cold-worked brass. The first effect of low-temperature annealing is a distinct though small increase in hardness. treated with mercurous nitrate solution, which causes Internal "Zinc Alloys with Aluminium and Copper." By W. ROSENHAIN, D.Sc., F.R.S., JOHN L. HAUGHTON, M.Sc., and KATHLEEN BINGHAM, B.Sc. The constitution and mechanical properties of alloys of zinc containing copper up to 10 per cent and aluminium up to 15 per cent are described in this paper. The constitution may be briefly summarised by saying that there is a ternary eutectic containing 4 per cent of copper and 7 per cent of aluminium, and two binary complexes, one the depressed eutectic of the aluminium zinc alloys, and the other formed from one constituent of the aluminium zinc and one of the copper zinc series. The ternary eutectic does not extend much beyond the alloys investigated. The rolling properties of the alloys have been studied, and it has been found that the addition of x per cent of copper improved both the hot and the cold rolling properties of zinc to a very marked extent. With the addition of more copper or aluminium, the cold rolling properties fall off rapidly. All the alloys are capable of not rolling, but those containing much copper and aluminium become very brittle on cooling. The mechanical properties of the alloys are somewhat complex. The rolled material has, in many cases, a very high elongation if tested soon after being rolled, but in the course of a few months this falls to quite a low value; in one case from 70 per cent on two inches shortly after rolling to I per cent after one year. Annealing at a tem. perature as low as 100° C. has a similar effect, although heat treatment has no influence on cast speciments. The rate of loading in the tensile test has also a very marked effect; with rapid loading the maximum stress is very high and the elongation very low, whereas under very slow loading this is reversed. These observations can be explained on the assumption of the existence in the alloy of a considerable amount of amorphous material, produced by rolling. Other experiments confirming this hypothesis are described. For castings of such a nature that the small shrinkage, which occurs on ageing in most of the cast alloys, would not be deleterious, an alloy containing 3 per cent of copper and 6 per cent to 15 per cent of aluminium is recommended. For rolled material, zinc containing I per cent of copper appears to be very promising. "A Model for Representing the Constitution of Ternary Alloys." By W. ROSENHAIN, D.Sc., F.R.S., Vice-Presi dent (Teddington). The paper describes a form of model by means of which the thermal-equilibria of a system of alloys containing three metals can be represented. The use of models for this purpose is well known, but the majority of models hitherto constructed have consisted of solid pieces or blocks, shaped in accordance with the data obtained by observation, and fitted together to form a complete model. With this form of construction, however, a comprehensive view of all the various surfaces and boundaries cannot be obtained, since the inner surfaces cannot be seen through the bulk of the solid model. In the model described in the present paper no solid blocks are used, but a construction of wires is adopted. The lines, curved or straight, along which the various equilibrium surfaces met one another are first set out by means of relatively stout wires. The surfaces themselves are then indicated by a network of finer wires, which, while indicating the shape and position of each surface, yet allow all the other surfaces, both below and above, to be seen at the same time. Dis tinction between the various surfaces is facilitated by the use of colour, each colour used being correlated to one of the phases which occur in the alloys. A model thus constructed allows of a comprehensive view of the whole of the equilibrium conditions and affords an insight into the constitution and behaviour of the alloys, which is not so readily obtained in any other way. The paper is illus trated by means of photographs, diagrams, and descriptions of a model representing an ideal ternary system of alloys, in which various typical features are represented. "Tin-phosphorus Alloys." By A. C. VIVIAN, B.A., A.R.S.M., Member (London). Investigation of alloys obtained by the use of pressure tubes, examination of constitution, isolation of phosphides found, and suggested temperature-concentration diagram up to 40 per cent or 50 per cent phosphorus contents. (Work at Cambridge under Mr. C. T. Heycock, F.R.S.). Ordinary phosphor-tin up to about 8 per cent phosphorus is prepared at atmospheric pressure. Under pressure in sealed vacuous hard glass tubes the alloys were made by putting the elements together in increasing proportions of phosphorus and heating slowly to 700° C., then cooling very slowly. Upon macroscopic and microscopic examination of the series the following points were brought to light. Phosphorus and phosphides insoluble in solid tin. Atmospheric pressure alloys (up to about 8 per cent phosphorus) consist of solid solution (a) of tin, in the az phosphide Sn4P3 (16:4 per cent), in a ground mass of pure tin-(maximum solid solution 14'7 per cent). Pressure tube alloys-conjugate solutions appear (6 per cent and 20 per cent). Cooling conditions of perfect equilibrium between the conjugate solutions existing in this range would give (for average concentrations below 16.4 per cent) a, in a tin ground mass a2, in aß eutectic would be found with concentrations above 16:4 per cent. Without stirring or seeding the freezing of these conjugate solutions exhibits a somewhat complicated series of happenings which are examined at some length with the aid of cooling curves taken from the alloys in the sealed tubes in an origininal manner. Above 20 per cent 8 crystallises from aß eutectic up to 8 composition 25.8 per cent Above this, ß crystallises Sn3P4. from By eutectic (y=SnP3 44 per cent P.). 31 per cent is By eutectic. Above By eutectic another range of conjugate solutions occurs in the series of which the lower solution is ☎ eutectic and the higher appears when solid to consist of SnP3 and fibrous red phosphorus very closely interwoven. All the phosphides have been isolated chemically or mechanically. "Some Notes on the Effect of Hydrogen on Copper." By W. 3. HOTHERSALL, M.Sc.Tech., and E. L. RHEAD, M.Sc.Tech., Member (Manchester). That copper in common with other metals is capable of CHEMICAL NEWS, Iodiomorphic Crystals of Electro-deposited Copper. dissolving various gases has been common knowledge for | "The Effect of Progressive Cold Drawing upon some "The Influence of Cold Rolling on the Physical Properties of Copper." By F. JOHNSON, M.Sc., Member (Birmingham). 155 critical ranges. The specific gravity determinations yield no collateral evidence of the existence of the critical ranges, but concordant results were rarely obtained. By taking the tests always from the centre of the rolled strips more regularity was obtainable and an increase was observable, which was steadily maintained up to 87 per cent reduction. The author draws attention to the inequality of distribution of strains in the rolled strips both laterally, vertically, and longitudinally. Test pieces taken from the centre always yield the highest results for hardness and tenacity. Suggestions are made with a view to obviating experimental difficulties in future work. Micrographs of the series show a progressive flattening and thinning of the crystal grains until a typically laminated structure is obtained in which the grains appear as parallel laminæ. Some space is given to theoretical considerations, and the author suggests that the crystal grains are forced by the rolling process into a homotropic arrangement in which slip can occur more smoothly and readily under tensional forces over the critical ranges than at other stages of deformation where tensional and compressional forces are both in action more or less equally. "The Study of Thermal Electro-Motive Force as an aid to the Investigation of the Constitution of Alloy Systems." By JOHN L. HAUGHTON, M.Sc., Member (Teddington). The constitution of alloy systems is generally investigated by means of thermal analysis and the microscopic examination of annealed and quenched specimens. Useful information can, however, be obtained by the study of the physical and mechanical properties of the series, and this paper deals with one of these, viz., the study of thermal electromotive force. The curves given, when the thermal electromotive forces of a series of alloys are plotted against the composition, are often very complex, but it can be shown that they are built up of branches which have one of three forms according to whether solid solutions or mechanical mixtures exist. of compounds may be shown by breaks in the curves, or in certain cases by maxima or minima. The existence The arrangement of the constituents in an alloy may have an effect on the thermal E.M.F. The theory of this is worked out, and the results of experiments with com. posite copper and nickel rods are given. In this case the E.M.F. against iron is nearly 50 per cent greater when the copper and nickel are in the form of small discs in series, than when they are in the form of a bundle of Practical details as to the methods parallel sheets. employed in the determination of the E.M.F.s for a series of alloys, together with a description of a simple apparatus designed for this determination are given. The paper concludes with an appendix describing the various thermal effects, dealing principally with the recently discovered Benedicks effects. "The Polishing and Etching of Zinc for MicroExamination." By H. H. HAYES, Member (Birmingham. Owing to the rapid increase in the industrial use of zinc in the form of thin sheet, it has been found imperative to develop a rapid method of polishing and etching The paper deals with a further investigation of the this material for microscopical examination in order to changes in properties resulting from the uninterrupted study the effects of different methods of annealing. In cold-rolling of electrolytic wire-bar copper, commencing the method described by Mr. H. H. Hayes before the with a thickness of 1.5 inches and finishing with a thick- Institute of Metals, the polishing is done with Globe ness of 0·033 inch, the number of passes being 17. The polish on chamois leather. No water must touch the surchanges in tenacity, elongation, Shore and Brinell hard-face during or after polishing. The etching medium is ness, lateral spread and specific gravity were determined. | By plotting these figures against percentage reduction of thickness, it was found that there were at least two well marked critical ranges of deformation, over which the tenacity, elongation, and hardness remain constant, whilst the width of the strips also remains constant, no lateral spread being noticeable. There were marked indications of other critical ranges also. A few determina. tions of the elastic limits (or limits of proportionality) were made, and they indicate a marked rise over the fuming nitric acid, in which acid the specimen is immersed for one second and immediately rinsed in water and dried by a hot-air blast. "Idiomorphic Crystals of Electro Deposited Copper." By W. E. HUGHES, B.A., Member (London). Idiomorphic crystals of electro-deposited copper can be formed at will, if suitable conditions of deposition are adopted. It was found by the author that two requisites are (1) slow disposition of the metal, and (2) as little A suitable device movement as may be in the solution. was found to be a small crlinder of metal, slightly | Analytical Chemist required, hollow at one end, suspended vertically in the solution betweed two anodes. The solution consisted of copper sulphate and perchloric acid. Photo-micrographs of crystals of copper so formed are given in the paper. The conditions obtaining when the deposition proceeds either sex, familiar with the Analysis of Plain and Alloy Steels, and Nonferrous Alloys. State age, experience, and salary required.-—Address, "Ferrous," CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, EC 4. under the circumstances stated are shown to be analogous Chemist, 27, recently demobilised, desires Post, to those in which good idiomorphic crystals are formed in salt solutions, as shown by Moore's experiments. And hence the author considers the formation of copper crystals and salt crystals to be governed by the same general laws of crystal formation. The work of Sieverts and Wippel mann and of Von Schwarz is considered in some detail. NOTES. home or abroad. Twelve years' experience General Analytical and Resea ch Work and Bacteriology. Excellent references -Address, R. W., CHEMICAL NEWS Office, 16, Newcastle Street, Far ringdon Street, London, E.C. 4 CH HEMIST.- Assistant, with experience of Analysis of Iron, Gunmetals, and Fuels, required by Works Laboratory near Newcastle-on Tyne. Age about 21. Starting wage £3 weekly. Position offers prospects of advancement and knowledge Replies will be treated in strictest confidence. Give fullest particulars. -Address, I. G. M., CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London. E.C. 4. Ex Officer, B.Sc. Honours Chemistry and Re search experience, seeks Position in Works or active Partner ship in some Chemical Industry. - Address, K. S., 80, Atwood Road, Didsbury, Lancashire. AN American firm is anxious to enter into communica tion with an English manufacturer for the supply of ferrotungsten, tungstic acid, and other tungstic compounds Considerable quantities are needed. Applications should EV be made to the Department of Overseas Trade, 35, Queen Street, S. W. 1. Old CATALOGUE OF BOOKS ON CHEMICAL TECHNOLOGYWe have received from Messrs. Crosby Lockwood and VENING CHEMICAL WORK-Labora tory, Clerical, or Teaching-wanted by Lady with B.Sc. training and works experience. Accustomed to library "digging."-Address, E. W., CHEMICAL NEWS Office, .6, Newcastle Street, Farringdon Street, London, E.C. 4. Son, 7, Stationers' Hall Court, London, E.C. 4, their Lady, B.Sc., seeks Post in Analytical Labora latest catalogue of books in Chemical Technology. It comprises works on Industrial and Manufacturing Chemistry (organic and inorganic) and a list of Practical tory.-Adress, H. J., CHEMICAL NEWS Office. 16, Newcastle Street, Farringdon Street, London, E.C. 4. Books for the Student, Analytical Chemist, Works Wanted, a Chemist, preferably with experi Chemist, and Manufacturers. The publishers will be pleased to forward a copy of this catalogue to any of our readers on application. AN EARLY CHEMICAL REACTION.-One of the earliest ence in Metallurgy and Electro-metallurgy, in Experimental Works near London.-Address, Metal Industries Limited, Sunburyon-Thames. FOR SALE. written records of a chemical reaction is to be found in the CHEMICAL APPARATUS (new) Copper Bible in the Book of Exodus. It will be recollected that after their departure from Egypt the Israelites marched for three days before reaching the well of Marab. On rushing to quench their thirst they found that the water was quite bitter and undrinkable. Moses, however, acting under divine inspiration, rendered the water potable by casting into it the branch of a tree. Thus far the Bible. Stills, Pans, &c.; Fusing Furnace on stand; Condensers Suction Tubes with solid brass caps and flexible tubing: Filtering Stands; Bunsen Burners, Burettes, Pipettes Thermometers; Flasks, Beakers, aud Funnels; also T. R. Corks, Rods, and Tubing Large assortment of dry and wet Chemicals in glass stoppered bottles, & Very suitable for equipment of private laboratory -Apply, Wharam's, Gilkes Street, Middlesbrough. The Proprietors of the PATENT No. 101663 for "APPARATUS FOR DISTILLING HYDROCARBONS," are desirous of entering into arrangements, by way of Licence and otherwise, on reasonable terms, for the purpose of exploiting the same and ensuring its full development and practical working in this Dean Milman, in a book written in 1846, draws attention to the scientific explanation of this phenomenon. He relates that one Buckhart, travelling through the country in which the above took place, came across a well called Howara (the identification of this with Marah is generally accepted). The water of the well was so bitter that neither men nor animals drank it. A sample of the water of a well near Howara was brought to England and analysed by a medical friend of Dean Milman, who gives the following account :-"The water has a slightly astringent bitterish taste. Chemical examination shows If in good condition, Sixpence per copy will be that these qualities are derived from the selinite or sulphate of lime which it holds in solution and which is said to abound in the neighbourhood. If, therefore, any vegetable substance containing oxalic acid (of which there are several instances) were thrown into it, the lime would speedily be precipitated and the beverage rendered agreeable and wholesome. The quantity of acid requisite for this purpose must be inconsiderable, as a pint of water, at its summer temperature in England, is scarcely capable of dissolving 20 grains of the selenite."-N. ASHERSON. NORTHERN POLYTECHNIC INSTITUTE, The Governors of the above Institute invite applications for the Post of ASSISTANT CHEMICAL LECTURER. Must have good Honours Degree. Commencing salary, including war bonus, £350 per annum. Particulars and forms of application may be obtained from the Clerk to the Governors. country. All communications should be addressed in the first i. stance toHASELTINE, LAKE, and CO., Chartered Patent Agents, 28, SOUTHAMPTON BUILDINGS, Chancery Lane, London, W.c. paid for any of the undermentioned numbers of the CHEMICAL NEWS which may be forwarded to this office : 3048, May 24th, 1918. 3064, January 3rd, 1919. 3066, January 17th, 1919. 3068, January 31st, 1919. 3069, February 7th, 1919. 3070, February 14th, 1919. 3075, March 21st, 1919. 16, NEWCASTLE STREET, FARRINGDON STREET, LONDON, E.C 4 |