CHEMICAL NEWS,' Dec. 2, 1898. Chemical Society.-Banquet to Past Presidents. 275 As you all know, however rude may be some of the methods of the art of agriculture, the investigation of the principles underlying its practices involves a wide range of scientific inquiry. It involves the chemistry of the atmosphere, of the soil, of vegetation, and of animal life and growth. That is to say, besides chemistry, it involves meteorology, botany, vegetable physiology, and animal physiology, to some extent. It is impossible to be a specialist in so many subjects, particularly in these days, and I can only say that in venturing to deal with these other branches of science we have taken great care to avoid mistakes. The wide range of the investigations must be accepted as some explanation of the fact that we have not contributed more of the results to the Chemical Society. Many of them being connected largely with other branches of science, have been recorded in other than purely chemical journals; whilst those having a more directly practical bearing have been published in the Journal of the Royal Agricultural Society, or in other agricultural publications-the Rothamsted papers now numbering considerably more than one hundred. But we feel that, however long or short may be the time that we shall still work together, we shall perhaps have done as much in opening up as in solving problems; and that we shall certainly leave plenty for our successors to do. In conclusion, considering that there still remain five of your honoured guests to speak, this is all I will say of my own career, and I will only now ask you, Mr. President, the Council, and the Fellows of the Chemical Society, to be. lieve that I esteem very highly the great honour you have conferred upon me to-night." the death of Lord Playfair. He was, as you know, one of the founders of the Society, and, before he died, the only survivor of those founders. I myself came in within three months of the foundation, and so had some knowledge of the Society's early doings. In fact, before I was really admitted to the Society, under the influence of the late Professor Graham, I undertook the translation of a paper by Redtenbacher and Liebig on The Atomic Weight of Carbon'; and that paper occupies eighteen pages in the first volume of the Society's Memoirs. I should say that, less than a fortnight ago, I received a letter from Lady Playfair, just before she left to visit her friends in America, in which she said with what interest he had looked forward to being present at the banquet appointed for June-but that was not to be. I first made the acquaintance of Playfair in Liebig's laboratory at Giessen, the year before the establishment of this Society, that is, in 1840. Playfair was at that time very busily occupied in translating the memorable work of Liebig, Organic Chemistry in its Applications to Agriculture and Physiology'; and before the session was over he left for this country with Liebig, who was to present the substance of that work as a Report to the British Association at Glasgow in September. You may be interested to know who there were from this country in Liebig's laboratory at that time. Besides Playfair and myself, there were Dr. William Allen Miller, afterwards Professor of Chemistry at King's College; Dr. Stenhouse, who has contributed so much to the Journal of this Society; Dr. Angus Smith; and, lastly, Dr. Edward Schunck. He and I are, I believe, the only survivors of that time among those from England who were with Liebig then. Of the Germans who were there, some of the names you will probably remember. There were Heinrich Will, Varrentrapp, Redtenbacher, Hermann Kopp, Scherer, Bromeis, Boeckmann, and others of various nationalities; but I believe that not one of these survives at present. Schunck joined the Society early in 1842, and he from that time to this has devoted himself to scientific investigation. He built a laboratory, and a museum devoted especially to specimens of organic bodies, in his own grounds on the other side of Manchester, where he still lives. He was, in fact, the oldest member of the Society, I believe, except Playfair and myself. He has worked indefatigably ever since; but I am very sorry to say he is not able to be here to-night, having had an attack of bronchitis, which renders it impossible, though it would have given him great pleasure to be present. Referring to that time at Giessen, I may say that Playfair, Stenhouse, and myself, each took our degree then; and Play-❘ fair, though joining with us, having gone with Liebig, the responsibility was left with Stenhouse and myself to give the usual supper to the other students of the laboratory, and a few distinguished guests, among whom was Bunsen, who was then at Marburg; and who, I am glad to learn from Sir Henry Roscoe, is still well. Stenhouse was much my senior. We had a large and lively party, but Stenhouse did not enjoy that sort of thing very much, and when the last bottle of champagne was opened, he said: 'Now, Gilbert, I shall leave you to it,' and away he went. That was, however, not near the end of the evening. They stayed a very long time, and we did not exchange the smoky atmosphere of the supper room for the clearer air outside until early morning. We then went round the boulevards of the little town, the Germans singing students' songs, and coming in time to the hotel where Stenhouse lodged, we serenaded him from the outside. Then someone tried the door, and finding it unfastened, the whole party went up, lighted candles, and serenaded him in bed. Next morning, there was a very capital caricature brought out, showing Stenhouse's rather long nose pointing in one direction, and his longer nightcap in the other. But this is enough of this kind of history, and I must now turn to rather more serious matters. It was in 1843 that I became associated with Mr. (now Sir John) Lawes, in agricultural investigation - a collaboration which has now extended over more than fifty-five years. In Sir EDWARD FRANKLAND-" Allow me to thank you, Mr. President, and the Council of the Chemical Society for this delightful entertainment which you have prepared for the Past-Presidents who have attained Jubilee rank. It was a generous, unique, and happy idea, which I feel sure we all heartily appreciate, not only as we sit at your hospitable board, but also when we reflect on the kind feelings which led to the conception of that idea. There used to be a phrenological organ entitled 'love of approbation,' and whether there is or is not a part of the brain told off to perform this function, I trust that chemists are not behind the rest of humanity in appreciating such an honour as you have conferred upon us on this auspicious occasion. Nothing could he more agreeable than thus meeting so many colleagues who are worthily keeping up the high reputation of the Chemical Society. There is but one drawback to our enjoyment, and it has been very feelingly alluded to by Sir Henry Gilbert, namely, that one who so recently stood at the head of our PastPresidents should not still be present amongst us. the lamented death of Lord Playfair, chemistry and science generally have sustained an immeasurable loss; for he was a binding-link between science and the State, always ready to fight for the cause of truth against prejudice and ignorance, and never ceasing in his efforts to bring home to our rulers the vast importance of the applications of science to the progress, health, and pros. perity of the nation. As one of his first pupils, and after a life-long friendship, I may be permitted to testify that his energy in this cause was prompted by sincere convictions and not by political exigencies. Had Playfair lived a few months longer, we should never have had the misfortune to make the acquaintance of that new variety of Homo sapiens the 'conscientious objector,' who is just now giving so much trouble to our magistrates. This is not a time to sketch, even in merest outline, the epochmaking work of the Society, but I may at least state my conviction that it will be found, on comparing the volumes of our Transactions with those of the corresponding societies of other lands, that, considering the number of workers in each case, England is not behind any other nation in research work, and this in spite of the almost total absence of that lavish state aid which nearly every other civilised nation enjoys. In view of the vast number of discoveries pouring out from chemical laboratories, 276 NEWS, Diffraction Fringes as applied to Micrometric Observations. (CHEMICAL N I hear it suggested that the day is not far distant when Faces so old and familiar I feel once again at the College, Yearning o'er aniline drops distilling from crystal alembic. Some are low down on the hill, and others are near to the Let us remember the past and forget not our absent companions; Fortune may come to us all; but youth will return to us never!'" (To be continued). miscible above 68° C., and incompletely miscible below that temperature. The law of equilibrium between incomplete mixtures and the vapours over them is investigated, especially at "the critical point," i.e., at the point where incomplete miscibility passes over into complete miscibility. It is pointed out that normal organic liquids always mix completely. Ethylene dibromide and formic acid mix on boiling, and separate into two layers when cold. The curves representing the cases of complete mixture are comparable in shape with those previously obtained by Mr. Lehfeldt for mixtures of alcohol and toluene, but they show a still flatter maximum; so much so that 60 per cent to 70 per cent of phenol may be added to water without apprecible effect on the vapour-pressure. To verify this point a differential pressure-gauge was designed; the construction and method of using are given in the paper. The behaviour of the liquid is apparently the same above and below the critical point. At temperatures not too close to the critical point the vapour-pressure of a saturated mixture is approximately the sum of the partial pressures, calculated for the two saturated solutions according to Raoult's law. Diagrams are drawn showing the characteristic surface for phenol-water mixtures, with the freezing points of water and of phenol traced out. Phenol melts under water at 15° C., and forms a cryohydrate containing 483 per cent phenol, melting at -1.0° C. Pro. S. YOUNG (Abstract of Communication).-The statement of Mr. Lehfeldt that normal organic liquids always mix completely, should be qualified. There are pairs of normal organic liquids which, though miscible in all proportions, approximate closely to partially miscible liquids: .g., benzene (b. p. 80° C.) and normal hexane (b. p. 69° C.). When American petroleum is fractionally distilled, the benzene which is present in small quantity does not come over at about 80°, but mostly at about 65°; the most probable explanation appears to be that benzene and hexane behave, as regards distillation, like miscible liquids, a view which is confirmed by an investigation of the boiling-points, and also of the specific gravities of mixtures of the two hydrocarbons, an account of which has lately been read before the Chemical Society, by Messrs. Young and Jackson, The boiling-point curve is similar in general form to that of phenol and water, as shown by Mr. Lehfeldt, though the deviation from the ordinary form is not so marked. Ten per cent of benzine has practically no influence on the boiling point of normal hexane, but 10 per cent of hexane lowers the boilingpoint of benzine nearly 3° C. Also there is always expansion on mixing benzine and hexane, the maximum reaching about 0'4 per cent. Dr. S. P. THOMPSON asked whether any relation had been observed between the vapour-pressure and the surface tension of the mixtures. Mr. LEHFELDT was not sure whether the surfacetensions of the components pass into one another at the critical point of mixture. Mr. L. N. G. FILON then gave an account of his paper on "Certain Diffraction Fringes as Applied to Micrometric Observations." It is to a great extent a critical investigation of a paper by A. A. Michelson on the same subject (Phil. Mag., vol. xxx., pp. 1-21, July, 1890). Michelson there describes a method for measuring the angular distance between the components of a double star, or the angular dimensions of very small celestial bodies, by means of interference-fringes, using two ad Mr. Shelford BIDWELL, F.R.S., President, in the Chair.justable slits in front of the objective of a telescope. If MR. R. A. LEHFELDT read a paper on "The Properties of Liquid Mixtures," being Part III. of his communications on that subject. It deals with partiably Miscible Liquids. Measurements are given of the vapour-pressure of mixtures of phenol and water. This pair of liquids is completely the star is double, or if it has an appreciable disc, then by widening the distance between the slits, the fringes become fainter, and in some cases almost vanish. But by still further widening the slit, the fringes reappear, disappear, and so on. In the paper (l.c.) Michelson develops the law of these appearances and disappearances, and gives an expression for the ratio of the angular distance between the components of the double star, or the angular radius, of the single source, to the distance between the slits, on the assumption that the slits are infinitely long and in finitely thin. Mr. Filon considers that this assumption is unjustified by the conditions of measurement; he reviews the original investigation, and modifies the results. He then proceeds to find equations to represent the intensity of light in the focal plane, for a point-source, and for a two-point source. These fringes are only visible over a certain rectangle, called "the rectangle of illumination" of the source. In the case of a two-point source, if the distance, perpendicular to the slits, between the geometrical images of the two points, is an integer-multiple of the distance between two fringes, the maxima of one system correspond with the maxima of the other, the fringes overlap, and their intensity is augmented. If, however, this distance should be an odd multiple of the half distance between the fringes, the maxima of one system correspond to the minima of the other, and if the fringes that are superposed are of similar intensity, the fringing is nearly obliterated, a result that agrees with Michelson's law. But it is now shown that for this phenomenon to occur (1) the rectangles of illumination of the two sources must overlap to a very large extent-this consideration was neglected by Michelson; and (2) the angular distance between the two stars, measured parallel and perpendicularly to the slits, must be less than a definite amount, depending upon the wave-length and the length and breadth of the slits. In astronomical cases, the second condition is generally satisfied. If the rectangles of illumination do not overlap they can be respectively distinguished, and thus the star can be resolved by direct ob. servation. If, however, an accurate measurement of the distance between the components is required by MichelBon's method, the rectangles must be made to overlap. The paper includes an investigation of a refractometer that Michelson (1. c.) proposed to use for increasing the effective aperture of a telescope; it is shown that Michelson's law is generally true for that instrument, but certain limitations are pointed out. Extended sources are next considered, and also the shape and size of the object. The paper concludes with the description of a method by means of which the ellipticity of a very small disc may be measured by these diffraction fringes in the special case where Michelson's law holds good. In reply to a question from Professor S. P. Thompson, Mr. FILON said that the minimum breadth of slit with which he had found it practicable to work, using monochromatic light with his telescope, was about half a millimetre. The PRESIDENT proposed votes of thanks, and the meeting adjourned until December 9th. NOTICES OF BOOKS. 277 simple experiment that the student can perform himself: Metrical Tables. By Sir GUILFORD L. MOLESWORTH. THE value of Molesworth's Pocket-book Tables is so well There is a good index, and, as it is bound in limp cloth and is only a quarter of an inch thick, it can be easily carried in the pocket. First Stage: Inorganic The Organised Science Series. Chemistry (Practical). For the Elementary Examina. tion of the Science and Art Department. By FREDERICK BEDDOW, D.Sc., Ph.D. London: W. B. Clive, University Correspondence College Press, 13, Bookseller's Row, Strand, W.C. ALTHOUGH professedly an examination book, the author has endeavoured to present his instruction in a sound, practical, and systematic way. Chapter I., Introductory Experiments, commences rather abruptly, "How to Bore a Cork," and simple descriptions are given of such useful operations as cutting and bending glass tubes, mounting platinum wires for flame tests, making a wash-bottle, &c. Then follows a list of the characteristic properties of some common substances, leading up to some simple quantita. tive experiments, and a note on weighing and the use of a balance; finally, a chapter is devoted to systematic analysis. Although the matter is necessarily rather condensed, and the style somewhat abrupt, it is evident that the author has his object, "practical instruction," well in hand, and to an intelligent student the book will prove of real value. CORRESPONDENCE. ETHERION. Chemistry for Schools. An Introduction to the Practical Study of Chemistry. By C. HAUGHTON GILL, late To the Editor of the Chemical News. Assistant Examiner in Chemistry at the University of SIR,-The above so-called new constituent of the atmoLondon, and Teacher of Chemistry and Experimental sphere discovered by Professor Brush was the subject of Physics in University College School. Tenth Edition. an article in the CHEMICAL NEWS of November 4th (vol. Revised and Enlarged by D. HAMILTON JACKSON, Ph.D. lxxviii., p. 221) by Sir William Crookes, who pointed out (Heid.), Demonstrator of Chemistry, Univ. Coll., the probability of it being simply a residue of water Bristol. London: Edward Stanford, 26 and 27, Cock-vapour, but suggested that when the complete paper came spur Street, Charing Cross, S. W. to hand more light might be thrown upon the subject. FOR a book of comparatively so small a size, a considerable amount of information has been introduced. That it has reached a tenth edition shows that it is appreciated, and this edition has been brought up to the present date of knowledge. There are plenty of illustrations, and each chapter concludes with a series of questions bearing upon the subject under discussion. Whenever possible, pains have been taken to impress a statement by detailing a The American periodical Science for October 14th contains a complete account of the investigation, and on examination it fully bears out Sir William Crookes's forecast. The paper is very lengthy, but the one solitary fact put forward is that powdered glass, sand, charcoal, &c., on heating give up a gas which, at greatly reduced pressures (between fifty-millionths of an atmosphere and zero, as indicated by a special form of gauge), in the 278 The Gases of the Atmosphere. Dec. 2, 1898. absence of a drying agent, conducts heat better than, the clearest possible terms his own feeling in regard to hydrogen! Now this, as was pointed out, is precisely what one would expect to get if water vapour is present, and it seems to be meagre evidence upon which to base the tremendous assumptions which follow in the paper. It is conjectured that "etherion will be found to consist of three or more gases forming one or more periodic groups of new elements"; that "etherion will at least account for some of the phenomena at present attributed to the ether"; that "it may be the medium of propagation of Röntgen rays in the vacuum glass and air!" The reasoning, too, in the paper strikes one as very strange, as in the following instances:-" A specimen of very fine white siliceous sand heated in vacuum gave a considerable amount of the new gas." Glass that had been deprived of etherion was exposed in a thin layer to air and then found, on exhausting and heating, to yield it "as freely as at first." And another experiment is given in which "several days of high heating, with frequent exhaustion, failed to wholly deprive the pulver. ised glass of its new gas." "From this and other reasons Professor Brush believes "the new gas resides in, and not simply on the surface of, glass!" As an instance of the speculative part of the paper, the following extracts are amusing: A curve, g h, is given in the diagram (CHEMICAL NEWS, vol. lxxviii., p. 197) showing the conductivity of the gaseous residue between pressures of 43 millionths and 0.38 millionth of an atmosphere, and at this last pressure the conductivity was found to be twenty-seven times that of hydrogen under the same conditions. Another curve, op, gave at p=0.12 millionth, a conductivity forty-two times that of hydrogen, and it is concluded as "reasonably certain" that, if the curve ef had been carried to as low a pressure as op it would have shown a conductivity of at least one hundred times that of hydrogen. On this astonishing assumption, the following table of molecular weight, density, specific heat, &c., is constructed :Comparison of Gaseous Properties. Professor Ramsay's share in the investigation. On the In the same year the Davy Medal was awarded to Professor Ramsay by the Council of the Royal Society, of which Lord Rayleigh was then a member and an officer. In conformity with an unwritten but very salutary rule, officers of the Society are debarred from receiving medals or other awards under the control of the Council during their tenure of office. Lord Rayleigh had, however, been the recipient of the highest honour which the Chemical Society has it in its power to bestow, and it is fair to surmise that he concurred in the award of the Davy Medal to his coadjutor in this work. If Lord Ray. leigh had been dissatisfied his colleagues on the Council were in a position to be aware of it, but no hint of such a feeling has ever escaped him, and the award was felt by everybody outside to be just. Is "Suum Cuique" so much in the confidence of Lord Rayleigh that he can pretend to know what conversations occurred between him and the numerous chemists whom he consulted, or that he is in a position to say that the Cavendish experiment was not mentioned by more than one of them? Professor Ramsay says that he directed Lord Rayleigh's attention to the Cavendish experiment, and because he says so I believe him, and shall continue to do so until, or unless, Lord Rayleigh states the contrary. This up to the present he has not done. The writer of anonymous letters may escape the charge of vanity, but when his communications assume the character of those which bear the signature of "Suum Cuique they are open to the more serious charge of malice. The Sugar in Orange-peel.-J. Flatau and H. Labbé. -While trying to isolate in a state of purity the odorous ether which exists in essence of orange, the authors noticed that it was always accompanied by a very small quantity of a substance easily soluble in water, and after treating a quantity of the peel in a certain manner they succeeded in isolating a substance presenting all the characteristics of a sugar. To identify this sugar they prepared its hydrazone by Emile Fischer's method, and finally decided that it was mannose.-Bull. Soc. Chim. de Paris. CHEMICAL NEWS, Dec. 2, 1898. Chemical Notices from Foreign Sources. CHEMICAL NOTICES FROM FOREIGN | phenyl-oxyacetic acid. SOURCES. 279 That this surmise is correct is demonstrated by the hydrolysis of the compound CHOCH-CHOC2H' -OC2H5 which is simply the di C6H4 (2)O· ethyl acetal corresponding to the above-mentioned NOTE.-All degrees oftemperature are Centigrade unless otherwise aldehyd. The hydrolysis of this acetal was effected by Julius Hesse (Comptes Rendus, cxxvii., p. 276), and the product resembled in all respects the orthoxy-phenyl-oxyacetic acid of the author. expressed. Comptes Rendus Hebdomadaires des Séances, de l'Académie des Sciences. Vol. cxxvii., No. 5, August 1, 1898. Action of Pure Phosphoretted Hydrogen on Copper Sulphate.-E. Rubénvitch.-Previous investigators obtained a black precipitate by the action of phos. phoretted hydrogen on copper sulphate, of an indefinite composition. The author investigates the subject thoroughly. He acts on a measured quantity of copper sulphate with phosphoretted hydrogen, then filters the precipitate, and washes with distilled water freed from air. All these operations take place in a vacuum. The copper phosphide is well defined and free from metallic copper; it corresponds to the formula P2Cu5. H2O. Apparently the reaction takes place in two stages; two unstable phosphides being first formed, which, in the presence of the oxygen of the air, are transformed-one into metallic copper and phosphoric acid, and the other into a black compound containing oxygen. In the absence of all traces of oxygen, the reaction takes place according to the equation Action of Bromine on Normal Propyl Bromide in presence of Anhydrous Aluminium Bromide.-A. Mouneyrat. The production of hexabromethane (CBг3-CBг3) by bromination with anhydrous AlBr3 of ethyl bromide in successive stages has already been discussed. The present paper treats of the application of the same method to propyl bromide. Derivatives of propane were obtained with have hitherto been satisfactorily produced by no direct method. A solution of aluminium bromide in bromine was used; the given substance and the bromine being in theoretical proportions, corresponding to the general equation C3HxBry+Br2-C3H(x-1)Bry+1)+HBг. No. 7, August 15, 1898. Atmospheric Carbonic Acid.-Albert Lévy and H. Henriet.-To collect the carbonic acid in the atmo spheric air, the latter is allowed to bubble rapidly through a dilute solution of potash or baryta. The authors have investigated the amount present during the day, night, and at different times of year. They found (1) that by their method all the free CO2 was retained by the potash (this being proved by connecting a second potash tube on to the first, which did not vary in weight); (2) there was always less than half a litre of CO2 to 100 m.c. of air; (3) that dilute solutions of various alkalis give exactly the same results; (4) that the variation in the amount of CO2 in the air was very small during six years. If a globe of air which had been freed from CO2 was left for some time in contact with potash, fresh CŌ2 was formed. This showed that in the air there were carbonaceous substances, which in presence of oxygen and an alkali form CO2. The amount of CO2 formed was considerably more after the air had been left in contact with alkali for two hours than after ten minutes; but after two hours no increase in the amount was perceived, showing that the whole of the carbon was probably transformed into CO2 in about two hours. The author gives tables of results for every day during three or four weeks. Berichte der Deutschen Chemischen Gesellschaft. Formation of Metallic Sodium by means of Peroxide of Sodium.-H. Bamberger.-It is very easy to prepare metallic sodium as a lecture experiment by means of the peroxide. To effect this it suffices to heat the latter with charcoal, graphite, or coke in a covered crucible to about 300-400°. The reaction is rather violent and should only be performed on a few grms. at a time; most of the sodium is deposited on the cover and the sides of the crucible, 3Na2O2+2C=2Na2CO3+Na2. Peroxide of sodium reacts still more violently with carbide of calcium. If an excess of carbide be used, amorphous carbon is deposited, and a part of the carbide remains When the residue is decomposed by undecomposed. water, in the first case hydrogen is given off, and in the second case hydrogen and acetylene. Action of Acetic Anhydride on the Anilides of the Bibasic Acids.-H. de Pechmann and W. Schmitz.Oxanilide boiled for a long time with acetic anhydride and acetate of sodium reacts according to the equationCO.NH.C6Hs CO.NH.C6H5 = +COOH.CH= CO.N(C6H5) C=CH2+2H2O. |