PUBLICATIONS RECEIVED. U.S. GEOLOGICAL SURVEY. Surface Water Supply of the United States, 1923. Part VI. Missouri River Basin. Price 50 cents. Part X. The Great Basin. Price 25 cents. Ground Water in the Ordovivian Rocks near Woodstock, Virginia. By George M. Hall. The Toklat-Tonzonz Region. By Stephen R. Capp. Geological Investigations in Northern Alaska. By Philip S. Smith. U.S. BUREAU OF STANDARDS. Circular 333. Specifications for the Manufacture and Installation of Two-Section, Knife-Edge Railroad Track Scales. Price cents. Scientific Paper 557. A Suggested New Base Point on the Thermometric Scale and the Inversion of Quartz. By F. Bates and F. P. Phelps. Price 5 cents. FORTHCOMING EVENTS. MANCHESTER LITERARY AND ROYAL SOCIETY OF ARTS. 66 New Patents. These particulars of New Patents of interest to Readers have been selected from the Official Journal of Patents, and are published by special permission of the Controller of His Majesty's Stationery Office. Latest Patent Applications. 32,308.--Chemische Fabrik Pott & Co.Process or production of viscose. November 30th. 32,430.-Frischer, H.-Concentration of nitric acid. December 1st. 32,264. Goldschmidt, S.-Process for oxidat.on of alcohol. November 30th. Hübsch, M. G.-Process for removal of phenols from tars, etc. November 28th. Specifications Published. 280,972.-Dreyfus, H. acetic anhydride. Manuafcture of 281,035.-Wallace, W. M., and Gregor, J. M.--Recovery of soda from its solu tions. 281,114.-Barnard, C. M., and British Alizarine Co., Ltd.-Caps and like head coverings. 271,881.-Frischer, H.-Methods of pro ducing volatile inorganic acids. Printed copies of the full Published Specifications may be obtained from the Patent Office, 25, Southampton Buildings, London, W.C.2., at the uniform price of 1s. each. Abstract Published. 279,095.-Hydrocarbons. Corson, M. G., 8108, Polk Avenue, Jackson Heights, New York, U.S.A. Acyclic and cyclic hydrocarbons; hydrogenized organic compounds, catalytic production of. Hydrocarbons are obtained by reacting calcium carbide with an alcohol, phenol, or chlorine derivative of a hydrocarbon in the absence of carboxyl groups, at 150-300° C. and about 12-40 atmospheres pressure. When ethyl alcohol is employed, any water present is first decomposed, giving acetylene which is withdrawn through a reflux condenser. The condenser is then removed and the vessel closed, when diethyl-acetylene is formed, which may be further treated with hydrogen and a suitable catalyst under pressure to produce hexane. In another example monochlorbenzene is employed, yielding diphenyl-acetylene (tolane) which may be treated with hydrogen and a catalyst to produce stilbene or di TRADE MARKS This list of Trade Marks of interest to Readers has been selected from the Official Trade Marks Journal, and is Published by permission of the Controller of His Majesty's Stationery Office. BITRATED. 458,398.-Chemical substances prepared for use in medicine and pharmacy.--International Chemical Co., Ltd, The Factory Braydon Road, London, N.16 December 7th. BITRATE. 485,399.-Chemical substances prepared for use in medicine and pharmacy.-International Chemical Co., Ltd., The Factory, Braydon Road, London, N.16. December 7th. THYLOX. 483,276.-Chemical substances for use in the purification of gas.-Koppers Products Company, Union Trust Buildings, Pittsburgh, State of Pennsylvania, United States of America. December 7th. 482,126. Illustration of the Tower of London for all goods in class 3 which includes chemical substances prepared for use in medicine and pharmacy. Charles Billing, trading as The Tower of London Soap Company, Clegg's Hotel, The Green, Hampton Court, Middlesex. December 7th. STELLAR ENERGY, THE CHEMICAL NEWS VOL. CXXXV. No. 3533. MERTON HOUSE, SALISBURY SQUARE, LONDON, E.C.4. TELEPHONES : RELATIVITY, GRAVITY, ETHER, PHOTO-ELECTRIC EFFECT. By F. H. LORING. (Continued from Page 393.) There is a well-known surface-tension experiment that will serve to illustrate the idea of making the total curvature minimum. a Take a small hoop, made of roughened wire, about three inches in diameter, and, with a good soap solution, form a film across it by simply dipping the ring momentarily into the solution. Take a few inches of fine sewing silk and join the ends so as to make a closed loop. Wet this loop with the solution; then lay the loop gently on the film, its plane being horizontal. The contour of the loop may be quite irregular, representing a good deal of curvature, and there will be no tendency for its shape to alter; but upon breaking the soap film within the loop by piercing it with a hot needle, the loop instantly assumes a perfect circle, thus representing a minimum of curvature. Now general relativity involves a spacetime conception that may in some way be translated into the æther under some sort of tension; but is tension the best word to use? It is easy to make a false step here, and like several of the words used in this article they must not be taken invariably in the literal sense. For example, in speaking of the atom, this does not always exclude the electron and its counterpart, the proton, for these electrical entities, whatever they may ultimately turn out to be, are essentially atomic. Similarly, in speaking of lines of force, the term can be translated into tubes of force, ribbons of force, or linear extension of force, according as the context may suggest. In this connection the word force might be objected to on some grounds, but it stands for a class of phenomena pretty well understood. The words are so chosen as to place the idea into the best representative class realising that by so doing an idea is narrowed down within certain reasonable limits. In speaking of c as a spreading constant, the inherent nature of radiation is made more evident. In the theory of relativity this constant is a limiting one for no velocity can exceed c. Why is this so? Is it because when any movement reaches the value of c spreading takes place? If this were true, then bullets fired from a strong enough gun with sufficient force behind them would spread when their velocity reached that of light. An impossible experiment, but the mind can easily extend the experiment beyond the practical limit; but the spreading is a difficulty.* This spreading idea calls to mind an attempt the writer made many years ago to reconcile the fourth dimension with this sort of effect (see Chemical News, 1915, cxII, p. 100, second column). classical Minkowski in his paper on relativity in which the conceptions of time by itself and of space by itself were forbidden, sought to avoid the emptiness of space by defining the velocity of light (c) as the ratio of the electro-magnetic to the electrostatic unit of electricity. This is, of course, a recognised relation. Sir Oliver Lodge, in his article on the æther in the Encyclopædia Britannica, 1926, Supplementary Vol. I, says: "What we do know is that light is an electro-magnetic phenomenon, and that it is entirely dependent on the properties of the æther. The æther involves or possesses properties expressible by two fundamental constants; one of them regulates the force of attraction between two electrified bodies, and the other the force of attraction between magnets. Neither constant by itself is yet known. But the value of the constants multiplied together is known it was discovered by Clerk Maxwell, and it is the reciprocal of the square of the velocity of light." Oliver Heaviside, in his "Electromagnetic Theory," 1893, Vol. I., p. 462, says: "It would appear that we must go to the æther to find the source of all energy." In order to unify the text, when quating, the diphthong is used, since the writer prefers this spelling to make a distinction between the ether of space and the chemical substance by the same name. The above surface-tension experiment is compiled from the instructions given by Risteen in his book, "Molecules and Molecular Theory," 1895, p. 87. (To be continued.) * The relativity of time and space is supposed to assist in understanding the constancy of c, but here an attempt is made to translate matters a little differently. LOW TEMPERATURE COLD BLAST PIG IRON TO BE USED FOR By A WELL-KNOWN ENGINEER. In connection with the low temperature carbonisation at, say, 1000° F. of bituminous coal to produce a hard smokeless free burning fuel there has long been a difference of opinion as to whether it is best to construct vertical retorts, intermittent or continuous, of fireclay or cast iron. The latter has a number of obvious advantages, including a much better rate of heat transmission, ease of making any desired shape, including off-take pipes, man-hole covers, and supporting rings, and the fact that metal is air-tight and gas-tight, thus preventing leakage of gas into the flues and altering the temperature. As against this, however, the objections to ordinary cast iron include a great tendency to oxidise and scale off under continuous heat conditions, even as low as 800900° F., resulting in severe wear and tear, and the objectionable property of "creeping," that is permanent distortion in shape. The 99 Coalite process at Barnsley, now in this respect reverted to the original practice of Thomas Parker, the Tozer" process at Ballengeich in Natal, the "Hird" process, and the E" retorts of the Fuel Research Board, are examples of the use of cast iron in spite of the troubles mentioned. 66 66 6 It is interesting to note that strong claims for low temperature retort construction are now being made on behalf of genuine cold blast pig iron. This is a speciality of Messrs. Robert Heath and Low Moor, Ltd., and it is maintained the well-known dense and tough character of cold blast iron, much superior to the ordinary hot blast iron, will overcome the difficulties of wear and tear. Naturally a product of this character using a cold blast of air in the furnace without any regenerator device costs a little more than hot blast pig iron because of the reduced thermal efficiency of the blast fur nace, but slightly increased capital expendi ture on a retort is a minor matter compared with the life, and the experiment will be watched with considerable interest. ADDENDA. In a footnote the writer says: The main point, as stated above, is that cold blast pig iron is known to be superior in quality to the ordinary pig iron with the hot blast, although naturally somewhat more expen sive to make because of the reduced thermal efficiency of the blass furnace. The theory is that because of these properties cold blast pig iron will give superior results for low temperature carbonisation retorts, and certainly the subject is of great interest, as cast iron has obvious advantages for retorts at say 1,000 F., but with the disadvantages in the case of ordinary iron of severe wear and tear and creeping." 66 TYNDALL'S EXPERIMENTS ON By SIR WILLIAM BRAGG, K.B.E., D.Sc., In 1845 Faraday made the surprising discovery that the vast majority of substances, not merely iron, nickel, and cobalt, were affected by a magnet, and showed also that the action was repulsive quite as often as attractive. Faraday's results excited the greatest interest, and were the starting point for many other researches. In fact, they paved the way for the work of Thomson and Maxwell, who came thereby to the establishment of the laws of electro-magnetism. Among the many workers who followed Faraday was Tyndall, who made certain interesting discoveries relating to the behaviour of crystals in the magnetic field. A very lively discussion sprang up as to the mode of interpretation of the new discoveries, particularly that of the so-called "diamagnetism." On the one hand, Faraday was satisfied that he could describe them in terms of his "lines of force": the majority, including Tyndall, referred everything to the existence of poles, magnetic and diamagnetic. Tyndall's experimental work, and the consequences which he drew from it, were devoted to the support of these views. When Faraday's conceptions prevailed it became clear that Tyndall's interpretation, of his own experiments in particular, must have been incorrect. His collected account of his researches published in the well-known "Diamagnetism and Magne-Crystallic Action " became a link in the chain of argument. never The recent analysis of crystal structure by means of X-rays throws some new light on those experiments of seventy years ago. We can see more clearly where Tyndall's conclusions were in error. But at the same time-and this has seemed to be of such interest that you might like to hear of it in the evening's discourse-the experiments of Tyndall are seen to be closely related to a modern research of immense importance, that of the effect of stress on the constitution and physical properties of materials. Let me tell you the story. 66 On the 13 of September, 1845, Faraday made one of his most important discoveries, that of a relation between magnetism and light. He found that when plane polarised light was made to traverse a piece of his heavy glass a borosilicate of lead, in a direction coinciding with that of lines of magnetic force, the plane of polarisation was rotated. He had thus been successful in showing that the action of a magnet did not require the co-operation of a magnetic substance such as iron for its manifestation, but might be directly connected with a substance of a different kind, namely glass, and a different activity, namely light. In the following months he tried to find some other connection between magnetism and this glass. He floated his glass on a liquid and tried whether he could move it by a magnet, without result. But on November 4 he succeeded in his search. "The bar of heavy glass 1 of an inch long and* of an inch square, was suspended by cocoon silk in a glass jar in principle as before, and placed between the poles of the last magnet. When it was arranged and had come to rest I found I could affect it by the magnetic forces and give it position. Thus touching diamagnetics by magnetic curves and observing a property quite independent of light by which we may probably trace these forces into opaque and other bodies as the metals," etc. 66 If 1 was the natural position on making the poles magnetic the glass swung into position 2 and on to position 3. If contact was united after 2 the tendency to 3 was diminished, i.e., was less than if there was no current. If whilst swinging contact of current was continued during vibration from 1 to 2 and broken from 2 to 3, then united from 3 to 2 and broken from 2 to 1 the bar was soon sent spinning round the whole circuit." The word "diamagnetic " is here used to denote substances through which, on his views, magnetic lines were passing. It is not yet used as an antithesis to paramagnetic. His new result obviously gave him intense pleasure, and in following it up he was so pre-occupied that he did not even go to the meeting of the Royal Society on November 20, when his paper on the "Action of Magnets on Light" was read. *Not filled in, but from other notes we know it was half-an-inch square, |