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Proceedings of the Chemical Society, Vol. 19, No. 269 |
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Proceedings of the Chemical Society, London,
Volume 19,
Issue 269,
1903,
Page 179-197
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P R 0 C E E D 11N G S OF THE CHEMICAL SOCIETY. VOl. 19. No. 269. Wednesday, June 17th, 1003. Professor W. A. TJLDEN,D.Se.! F.R.S., President, in the Chair. Measrs. E. S. Bedven and c1. Rawson were formally admitted Fellows of the Society. Certificates were read for the first time in favour of Messrs. : Percy W. Gent, 7984, Ridge Street, Newark, N.J., U.S.A. Henry William Lawrence, Wellington, New Zealand. Herbert Stanley Redfern, B.Sc., Ningpo, China. Frank Gurney Smith, 7, Luxemburg Gardens, Brook Green, W. The PRESIDENT GENERALgave notice that an EXTRAORDINARY MEETISG will be held in the Society’s Rooms on Thursday, July 2nd, 1903, at 6 p.m., to consider the proposal of the Council to make certain alterations in Bye-law I.,and in Circulars Nos.2, 3, and 4 in the Appendix. The proposed changes are :-I. To alter Bye-lam I., page 13, lines 3 and 4, by deleting the words ‘‘ one year.” The Bye-law at present reads :-I‘. . . . . ; and he shall” ‘I be entitled, so long as his annual subscription be not one ” “’year in arrear, to one copy of the annual publications of” “the Society. . . . , .” 11. To alter the Circulars in the Appendix as follows :-In Appendix, No. 2, ‘‘ Letter notifying the Election of a Member,” 5th and 6th lines, p. 26, delete the words “the Assistant I‘Secretary.” After the words before admission.” ” ccdd the words “Payment should be made direct to the Society’s Bankers ( ) either by Cheque or Post Office Order crossed a/c ‘ Chemical Society.’ Your re-mittance should be accompanied by the enclosed Form with your Name and Address filled in.” ,, No.3, “Annual Circular Letter of Treasurer,” delete fram ‘(Ifpaid” to end of circular, and substitute the same words as added in No. 2. ,, No. 4, ‘‘ Annual Circular Letter of Treasurer to Fellows who are two years in arrear of their Subscriptions,” delete from “Payments should be made ” to end of circular, and substitute the same words as added in No. 2. PRESENTATION OF THE LONGSTAFF MEDAL. THEPRESIDENTspoke as follows : We have so recently celebrated the Centenary of the Atomic Theory that it is a matter of interest to notice that, in the award of the Longstaff Medal on the present occasion, we honour the practical fulfilment of the deductions from that great conception.Dalton himself. represented in his diagrams atoms of solid bodies like ice arranged with reference to the crystalline form of the solid, but for three-quarters of a century successive writers could merely speculate as to their possible order in space of three dimensions. The discoveries of Pasteur in connection with hemi- hedrism in crystals, and the study of the lactic acids by Wislicenus, prepared the way for the development of the theory of stereo-chemistry by Van’t HOE and le Be1 in 1874. But while that theory has prospered and has led to innumerable developments in the study of the compounds of carbon, and although it must have been always obvious that if the idea of a tetrahedral configuration was valid for compounds of one element a corresponding idea should be equally 181 applicable to those of othgrs, the demonstration of the facts upon which such a development must rest has only been accomplished within the last four years.To Professor William Jackson Pope the Council has awarded the Longstaff Bledal, by a unanimous vote, for his researches on the stereo- chemistry of compounds of elements other than carbon. In 1893, Professors Kipping and Pope prepared the d-bromo-and d-chloro-camphorsulphonic acids? and by the use of these and other powerful optically-active acids, Mr. Pope has succeeded, not only in resolving into their active components certain racemic bases which had been found irresolvable by the use of tartaric acid, but in 1899, by the use of d-camphorsulphonic acid, he separated the dextro- and laevo-modifi- cations of a synthetical tetralkylammonium base, and thus definitely established the existence of asymmetric optically active nitrogen compounds. Since that time, by similar methods, he has obtained the dextro- rotatory methyl ethyl thetine, a dextrorotatory tin compound, and both forms of a selenetine, thus demonstrating the fact that the elements nitrogen, sulphur, tin, and selenium are each capable, like carbon, of producing asymmetric combinations possessing optical activity.We therefore now possess direct experimental evidence in regard to the compounds oE carbon, tin, sulphur, and selenium, as tetrad elements and of nitrogen as a pentad, so that it may confidently be expected that not only will the phosphorus series of elements be found capable of producing pairs of enantiomorphous compounds, but, pos- sibly, similar modifications of oxonium bases may be discovered,and some of the metals, such as platinum, cobalt, and chromium, may be found to exhibit similar phenomena.The doctrine of valency, no less than the doctrine of atoms, in its application to all ordinary terrestrial chemical phenomena, is thus triumphantly established. Professor Pope, it gives me great pleasure to be the medium of communicating to you the congratulations of the Council, and in hand- ing you the Longstaff Medal I express the feelings of the whole chemical world when I say that we trust you will have health, and strength, and time to continue the researches which have already yielded such a rich harvest of splendid results.Professor POPE,in expressing his sense of the honour done him by the award of the Longstaff Medal, desired to acknowledge gratefully the assistance which the Research Fund Committee had given to his work; it would be difficult to over-estimate the extent to which the Research Fund of the Chemical Society has contributed to the encouragement of chemical investigation in Great Britain. He wished also to record his indebtedness to his old friend and teacher, 152 Dr. H. E. Armstrong, who first taught him to look upon our science as a living and growing branch of knowledge, and inspired him with a desire to contribute something towards its development.Dr. G. B. LONGSTAFF, expressing his great pleasure at beingin present on this occasion, said that the researches for which Professor Pope had been awarded the medal considerably advanced our con- ceptions of the atomic theory in so far as they broke down some of the apparent barriers between carbon and the other elements. He recalled the fact that his father, who had been a friend of Dalton’s, was not only a Fellow of this Society from its commencement, but also the founder of Chemical Societies in Edinburgh and Glasgow, and was, moreover, instrumental in placing on a working basis the Research Fund (first suggested by Dr. Miller) to which Professor Pope had referred. Nevertheless, the name of the donor of the medal would have remained obscure except for the reflected light thrown on it, as it were, by the great names of an already long succession of eminent medallists.A ballot for the election of Fellows was held and the following were subsequently declared duly elected : Henry James Aubrey. John Howard Linday. George Barger, B.A., R.Sc. Charles Edwin L. Livesey, B.Sc. Colin Noel Bennett. John Christopher Mann. Wilfrid W. 0. Beveridge. Alfred Ernest Moore, B.A., B.Sc. Charles Drake Bibby. Arthur Moore. Henry J. W. Brennand, B. A., M.B. George Marshall Norman, B.Sc. William Godsell Burghard. George Harry Parry. Ernest Bury, M.Sc. Charles Stanley Pircell. Thomas Campbell. Thomas Rhind, M. R. C.S. Albert James Carrier, B.Sc.Charles Joseph Smith. Edwin Jesse Fairhall. James Cruickshank Smith, B. Sc. William Hunter Gandy. Dennis Tyrrell. Francis Gerald Harmer. Norbert Van Laer. Frank William George King, Sidney H. Woolhonse, M. A., B Sc. Henry Wolff Levy. Of the following papers, those marked * were read : “96. “The estimation of arsenic in fuel.” By T. E. Thorpe. An account was given of a method of estimating the amount of arsenic in fuels which is accurate, fairly rapid in execution, and which has the additional merit of directly distinguishing between the arsenic which is volatilised on burning the fuel and that which remains fixed in the ash. The process consists simply in burning a known quantity 183 of the finely powdered coke or coal in a stream of oxygen, passing the products of combustion through a suitable absorbing apparatus, and determining the amount of arsenic so absorbed as well as that left in the ash.The estimation of the arsenic in the solutions may be made by means of the Marsh apparatus and comparison with standard deposits of arsenic, or preferably with the electrolytic method described in the subsequent communication, The accuracy of the method was tested by burning fuels containing known quantities of arsenic, added in the form of arsenical pyrites. “97. The electrolytic estimation of minute quantities of arsenic, more especially in brewing materials.” By T. E. Thorpe. An electrolytic method for detecting arsenic appears to have been first suggested by the late Professor Bloxam (Quart.Jozlrn. Chem. Xoc., 1861, 13,12 and 338), but in its original form it, had several disadvantages which have prevented it from being generally adopted by chemists, The process has been carefully investigated in the Government Laboratory, and in the form described in the present communication it is easy of application, and is capable of giving trustworthy results with a comparatively small expenditure of time and trouble. The test may be applied to malt and malt substitutes, wort, hops and hop substitutes, beer, yeast and yeast foods, finiogs, &c. The advantages of the electrolytic method are :-1. That it obviates the use of zinc. 2. It is simple in execution, is under perfect control, and may be carried out under such conditions that the results obtained by different operators are strictly comparable, inasmuch as with a current-strength of fair regularity the evolution of the gas is practically constant and uniform.3. The whole of the solution to be tested for arsenic may be added to the apparatus at once, so that during the whole time of testing the arsenic is under the influonce of the ‘I nascent ’’ hydrogen. 4. It has been established that such amounts of arsenic as are present in beer or its ingredients are evolved as hydrogen arsenide during the 30 minutes occupied by the test. The nature of the material associated with the arsenic is found to exercise no inhibiting effect on the formation and evolution of the hydrogen arsenide.Aqueous extracts of malts and worts may be added directly to the electrolytic apparatus without previous destruction of the organic matter as required by the zinc and acid process. 5. The deposits obtained are more uniform in character than those furnished by the zinc and acid method, and admit therefore of more accurate quantitative comparison, 6. The process allows of the simultaneous execution of a number of estimations of arsenic, depending upon the arrangement of the rheostat. The disadvantages of the method are :-1. The initial cost of the apparatus as compared with that employed in the zinc and acid method. 2. That it can only be applied when an electric current of sufficient intensity is available.DISCUSSION. Dr. THORNEsaid the electrolytic process would prove of the greatest value to the large number of chemists who had to test for very small quantities of arsenic. The Marsh-Berzelius process was very reliable and accurate, and had been rightly recommended by the Committee of the Societies of Chemical Industry and Public Analysts, but those who used it knew the difficulty of obtaining zinc and hydro- chloric acid free from arsenic, and hence these reagents must be care- fully purified if the test was to be satisfact-orily carried out. In the process just shown, these difficulties were obviated. He had had the opportunity of seeing the method in operation, and could therefore speak as to its satisfactory working. Mr. ARTHURR.LINGalso thought that the electrolytic process would doubtless prove much more convenient than the Marsh-Berzelius method, which, in the case of many materials, necessitated the destruc- tion of organic matter. In the set of standards exhibited, the mirrors obtained in the presence of glucose appeared to be less intense than those produced in the absence of organic matter, from the same weight of arsenic, by the Marsh-Berzelius method. Mr. WILLIAM believed that the electrolytic method sug- THOMSON gested by Lord Kelvin and the ingenious apparatus devised by 'Dr. Thorpe and his colleagues may ultimately afford the most practicable means of detecting arsenic in beer and food-stuffs. He had tested one of the appliances, and had found that it would not detect the presence of more than about 1/350th of a grain of As,06per gallon, whilst the zinc and acid method easily detects 1/1000th of a grain per gallon when using 50 C.C.of the solution. Assuming at first that this difference was due to an insufficient surface of cathode, he used a much larger area of platinum wire gauze, but 185 obtained the same results with regard to the size of mirrors as those obtained in Dr. Thorpe’s apparatus. Platinum seems to retain minute quantities of arsenic, but when a pure zinc cathode is employed the 1/1000th part of a grain per gallon can easily be detected when using 50 C.C. of the solution. He could confirm Dr. Thorpe’s observations that minute quantities of arsenic in the form of pentoxide cannot be detected by the electro- lytic method, l/ZOOth of a grain per gallon (using 50 c.c.) yielded no mirror at all with the platinum anode, and gave an approximately half-sized mirror with the zinc anode.In other respects, his results diffured from those obtained by Dr. Thorpe. He found that both amyl alcohol and sugar seriously reduced the size of the mirrors, and he was of opinion that it is unsatisfactory to test beer directly in Dr. Thorpe’s apparatus. Dr. MCGOWANsaid that, together with Mr. R. B. Floris, he had during the past year examined a large number of samples of anthracite for arsenic. The method which, after some preliminary experiments, they had employed in this work was a modification of Newlands and Ling’s basic process.Although the results obtained were very con- sistent, and, as they believed, accurate, yet this process had the dis- advantage of being an indirect method with regard to the ‘‘ volatile ” arsenic present. Obher things being equal, a direct method such as that now brought forward by Dr. Thorpe was preferable. Dr. THORPE,in reply to Mr. Ling, stated that he had not been able to perceive any difference in the intensity of the mirrors produced from a known quantity of arsenic in the electrolytic method as com-pared with the Marsh-Berxelius method. A comparison of the standards in the two cases, as shown on the table, would prove that there was no practical difference in the two series. In reference to what fell from Mr. Thomson, he might say that attempts had been made to increase the activity of the cathode by depositing platinum black upon it, but nothing seemed to be gained thereby.Experience showed that the best and most uniform results were obtained by keeping the metallic surfaces as clean and bright as possible. ‘98. “Crystdlised ammonium sulphate and the position of am-monium in the alkali series’’ By A. E. H. Tutton. The author has hitherto shown that the morphological and physical properties of the crystals of the normal sulphates and selenates of potassium, rubidium, and cesium follow the order of progression of the atomic weights of the three alkali metals. An analogous study 186 of normal ammonium sulphate indicates that this salt stands in the series of normal alkali sulphates between rubidium and caesium sulphates, and very close to the rubidium salt, as regards the following nine properties :-solubility, molecular volume, distance ratios (topic axes), refractive indices, axial ratios of the optical ellipsoid, molecular refraction along axial directions, mean refration equivaIent both for the crystallised and the dissolved salt, and the general optical scheme which governs the optic axial angle phenomena.With respect to all these properties, the replacement of the two atoms of potassium by the ten atoms composing the two NH, groups is accompanied by an effect but slightly greater than when two atoms of rubidium are substituted for those of potassium. The specifically different nature of the ammonium radicle as com-pared with a metallic atom of the alkali group asserts itself in regard to the morphological angles and axial ratios, the specific refraction, certain details of the distance ratios and the optic axial angle phenomena, and in the development of only one instead of two cleavages.Yet even in the case of thecrystallographical angles, this difference is only manifested with regard to the direction of the change of angle on replacement, and as far as the amount of change is concerned the ammonium compound stands between the rubidium and caesium salts, and somewhat nearer to the latter. It is indeed, surprising that the introduction of eight additional atoms should be accompanied by less change in the exterior angles of the crystals than when an exchange of cmiurn for potassium atoms occurs.In short the specific constants indicate the peculiar nature of the ammonium radicle, whilst the molecular constants show that ammonium occupies a place in the alkali series immediately after rubidium. This result opens up questions of the arrangement of the atoms in the molecule and the closeness of the packing of the molecular structural units in the crystal edifice. It suggests that either the atoms have a range of motion inside the molecular dimensions suffi- ciently wide to admit eight more atoms without altering those dimen- sions to an appreciably greater extent than when the transposition of rubidium and potassium atoms is effected, or that the structural units are so loosely packed, that is, the amount of free space is so large as compared with the amount of matter in the whole space defined by the distance ratios, that there is adequate room for the increase of the material part of the molecule by eight atoms, without separating the centres of contiguous molecules more than when a simple metallic interchange occurs.187 *99. (‘The action of hydrogen on sodium.” By A.Holt, jun. Pieces of sodium free from oil were placed in a nickel boat and heated in a combustion tube through which a slow current of pure dry hydrogen was passing. An ordinary small combustion furnace without top tiles mas employed, and it was arranged so that, whilst the lower part of the tube was strongly heated, the upper portion was kept at a lower temperature in order that the hydride might condense on it.The hydride thus obtained consisted of colourless matted crystals, a hairy deposit not unlike cotton wool, and a white powder deposited next to the glass. The hairy material was formed on and above the powder in front of the boat, whilst the crystals projected from the surface of the tube at either side of the boat. The analysis was performed (i) by decomposing the hydride with dry, air-free hydrogen chloride, collecting the hydrogen due to the reaction and estimating the sodium chloride formed by titration with silver nitrate ;(ii) by decomposing the hydride with absolute alcohol, collecting the hydrogen evolved, and estimating the sodium in the alcoholic solution by titration with standard acid.The ratio of sodium to hydrogen showed that the hydride had the composition NaH, as already stated by Moissan. The hydride mas instantly decomposed by water, forming sodium hydroxide and hydrogen, this result also occurring in air after a few minutes; it was at once decomposed by hydrochloric acid, the de- composition being accompanied by flame and a detonation. The bydride was immediately attacked by nitric and sulphuric acids, hydrogen sulphide, and alcohol, but ether, benzene, and mercury were without action on it. With phenol and ammonia, it reacts only when heated, forming sodium phenoxide and sodamide respectively. Carbon dioxide, when perfectly dry, has no action on the hydride at the ordinary temperature, but on heating, a reaction takes place with the formation of carbon and a carbonate, The partially dried gas reacts with the hydride at the ordinary temperature, yielding a formate and carbon.When heated with ferric oxide, the hydride gives a f errs te. The combination of hydrogen with sodium appears to take place only when the latter is in a state of vapour; the sodium probably interacts only when it is partially monatomic. 188 100. ‘‘ The action of halogens on compounds containing the carbonyl group.” By Arthur Lapworth. Although bromine acts very slowly on a dilute aqueous solution of acetone, yet, in presence of alkali, bromination occurs readily. It is now found that acids also accelerate the speed of substitution to an extent which depends mainly on the concentration of the hydrogen ions, although the nature of the anion appears to have some influence. In the author’s experiments, the concentration of the bromine was always considerably less than that corresponding with one molecular proportion, and at constant temperature the velocity with which the bromine disappeared was nearly independent of its concentration.With sulphuric acid between the concentrations 0*4N and 0*04N,the velocity increased somewhat less rapidly than the concentration of the acid, but slightly more rapidly thar that of the acetone. The relative velocities of reaction with 0.4N sulphuric, nitric, and hydrochloric acids were about 1-19 :1.20 : 1-36.The velocity was not affected if the acetone was left in contact with the dilute acid for several days before the introduction of the bromine. Preliminary experiments with chlorine indicate that in presence of much acid it is removed at about the same speed as bromine. These facts confirm the view that the bromination is not a process of direct substitution, but is preceded by a reversible change of the acetone, accelerated by acids or alkalis, to a second form, probably the enol, this modification being brominated nearly instantaneously. It has already been shown that in many cases acids promote the attain- ment of equilibrium between keto?zic and enolic modifications (Trang., 1902, 81, 1500, and Proc., 1903, 19, 149). The action of acids in accelerating substitution is not confined to aqueous solutions, but may be readily followed in other solvents.The action of bromine and chlorine on other carbonyl compounds, as, for example, malonic ester and acetic anhydride, is greatly accelerated by acids, Even dry acetic acid is readily converted into its mono-bromo-derivative on the water-bath if it is first saturated with hydrogen chloride or bromide. The latter observation explains the action of a small quantity of phosphorus or phosphorus halogen compounds in promoting the action of chlorine and bromine on carboxylic acids, and the introduction of a suitable amount of the acid chloride appears equally effective when the acid contains water. 189 101. (‘Reactions involving the addition of hydrogen cyanide to carbon compounds.” By A.Lapworth. In order to ascertain the conditions under which hydrogen cyanide is most rapidly taken up by carbon compounds, camphorquinone was brought into contact with that substance in the presence of different agents which might possibly influence the reaction velocity, a rough measure of the latter being obtained by noting the speed with which the colour of the quinone disappeared. The reaction, which was very slow in aqueous solution and was ret.arded by acids, was extremely rapid in presence of strong bases, and was accelerated by salts of weak acids. This result indicates that the change is effected by the cyanogen ions, a view confirmed by further experiments.The great additive power of “nascent ” hydrogen cyanide as com-pared with that of the agent in the free state is now readily under- stood, as the former occurs in presence of potassium cyanide. When the addition product is fairly stable towards alkalis, it is not necessary actuaIly to liberate the hydrogen cyanide. Camphorquinone may, in a few seconds, be largely converted into its cpanohydrin by shaking with a concentrated aqueous solution of potassium cyanide. Benxylidene benzylcyanide gives more than 30 per cent. of the theoretical amount of diphenylsuccinonitrile if warmed for 20 minutes in alcoholic solution with excess of potassium cyanide, although it does not appear to unite with hydrogen cyanide in the absence of its salts ;phorone is rapidly converted into phoronocitrile under the same conditions.With potassium cyanide, benzaldehyde yields mandelonitrile. The latter compound condenses with the former in presence of bases to yield hydrogen cyanide and benzoin, The well-known benzoin condens- ation may therefore be represented as the result of the formation of the unstable cyanohydrin of benzoin by the ordinary addition process, CHPh(oH).CN +PhCHO =OH-CPh(CN)*CHPh*OH, where the mandelonitrile behaves as the hydroxy-derivative of benzyl cyanide, a substance which is known to condense readily with benz- aldehyde. 102. “The acetoacetic ester synthesis.” By A. C. 0. Ham and A. Lapworth. Within the last four years convincing evidence has been accumu-lated to show that Claisen’s hypothesis (Annalen, 1897, 297, 92) as to the mechanism of the synthesis of &ketonic esters and similar com- 190 pounds by the use of sodium or sodium ethoxide is incorrect, and, moreover, the facts which led to the formulation of this theory have been shown by Dieckmann (Ber., 1900, 33,2677) to be capable of a far simpler explanation.The authors’ observations, which are being extended, confirm the view that the acetoacetic ester synthesis is essentially the result of an addition process in which a metallo-organic compound becomes attached to thecarbonyl group of an ester = MeCLCH,*C02Et \OEt (compare Michael, Ber., 1900, 33,3736 ; and Lapworth, Z‘mns., 1901, 79, 1269). Ethyl bromoacetate was allowed to react with certain esters in presence of zinc and magnesium; with ethyl oxalate, good yields of ethyl oxaloacetate were obtained ; with ethyl acetate, the product was mainly ethyl y-bromoacetoacetate, the latter compound being produced by an exactly similar process, excepting that the reaction occurs between two molecules of ethyl a-bromoscetate without the intervention of ethyl acetate.Fittig, Daimler, and Keller (Annulen, 1889, 249,184) employed this modification of the acetoacetic ester synthesis in preparing diethyl ketipate (diethyl oxalodiacetate), but the complete analogy between the two methods appears to have hitherto escaped notice. 103. (‘Rimu resin.” By T. H. Easterfield and B. C. Asto n. Rimu (Dcccridium cup~essinum; natural order, Con%$eerae) is one of tho most valua5le of the New Zealand timber trees, the cracks or shakes in the heart wood being nearly always partialIy or completely 611ed by a hard pink resin with a distinctly crystalline fracture.The chief constituent (75 per cent,) of the resin, a crystalline acid, for which the name rimuic acid is proposed, melts at 192-193’, distils with very slight decomposition at 296-300’ under 21 mm. pressure, and is optically act-ive. It is easily soluble in alcohol or ether, and dissolves sparingly in water or light petroleum. Its formula, C,,H2,,0,, is supported by analysis, molecular weight determinations, titration values, and analysis of barium, lead, and silver salts. The barium compound is the most characteristic of the salts ;it crystallises in mell- defined, square plates having the composition Ba(C16H1003)2,14H20.The alkali salts are very soluble and do not separate from solution in the presence of excess of alkali. Rimuic acid is laevorotatory, having [a],,-159’ in a 10 per cent. alcoholic solution; it yields benzoyl and acetyl derivatives, and its formula may be thus represented: C,,H,8(OH)*C0,H. Like most of the acids from the pine resins, it yields no esters when treated with alcohol and hydrochloric acid. The acid yields two crystalline nitro-derivatives when nitrated in cold glacial acetic acid solution. 104. “Note on the karaka fruit.” By T. H. Easterfleld and B. C. Aston. The kernel of the fruit of the Karaka tree (Corynocarps Zavigata ; natural order, Amcardiacece), is a staple article of food amongst the Maoris and Morioris, In its raw state, it is bitter and very poisonous, but when baked and subsequently soaked in water its toxic properties disappear.Examination of the kernels shows that they contain 15 per cent. of a harmless, non-drying oil and that the aqueous extract of the nut contains mannite, mannose, and dextrose. When the extract is distilled, it yields a considerable quantity of prussic acid. From the aqueous extract, Skey obtained a bitter glucoside, karakin, which he stated, melted at 100’ and contained no-nitrogen; the authors find, however, that karakin is highly nitrogenous, and when pure melts at 122’. It is most readily obtained from an alcoholic extract of the kernel by removing the alcohol under diminished pressure and recrystallising the residue from warm water.Karakin, which has the formula C,,H,,O,,N,, crystallises in leaflets, and like amygdalin is only slightly toxic when removed from the enzymes with which it is associated. A second glucoside, Corynocccrpin, can be obtained in small quantity by evaporating the aqueous extract at a temperature below 50’ and extracting with ether. As this glucoside cannot be detected in the freshly prepared extract, and as the karakin disappears during the evaporation, it is probable that the second glucoside is a product of the partial hydrolysis of karakin. Corynocarpin crystallises in fine needles, melts at 140°, and is less soluble in hot alcohol than karakin. 105.“The slow oxidation of methane at low temperatures, 11.” By W. A. Bone and R. V. Wheeler. The authors describe an apparatus for the closer investigation of slow combustion processes. This is essentially a closed system in which the relzting gaseous mixture can be circulated day and night 192 continuously, at a uniform rate, (1) over a heated surface the temperature of which is kept constant, and (2) through suitable washing and cooling vessels for the removal of soluble or condensable intermediate products. A specially devised manometer allows of pressure records being taken at regular intervals, so that the velocity of the oxidation may be measured. Further experiments with this apparatus on the interaction of methane (2 volumes) and oxygen (1 volume) at 450’ and SOO’, whilst they entirely confirm the authors’ previous conclusion that neither hydrogen nor carbon is liberated at any stage of the oxidation, and that the final products consist simply of carbon monoxide, carbon dioxide, and steam, have proved the t.ransient formation of form-aldehyde as an intermediate product, In one experiment, 13 per cent., and in another as much as 22 per cent., of the methane burnt was obtained as formaldehyde which had been rapidly removed from the sphere of action by passing the reacting mixture through cold water each time it left the tube containing the heated surface.The authors conclude that the oxidation of methane involves the following stages :-(1) The simultaneous formation of formaldehyde and steam, by the bimolecular reaction, CH, + 0, = CH,O + H,O. (2) The further oxidation of this formaldehyde to carbon monoxide, carbon dioxide, and steam.This is probably effected as the result of the simultaneous occurrence of the following reactions :-(a) The bimolecular reaction, CH20+ O2= CO, + H20. (6) The trimolecular reaction, 2CH20+ 0, = 2CO + H20. 106. The alkylation of sugars.” By T. Purdie and J. C. Irvine. The method of alkylating hydroxyl groups by means of dry silver oxide and alkyl iodides does not appear directly applicable to aldoses or ketoses, and leads to oxidation and subsequent changes of some complexity ; but a-methylglucoside and cane sugar can be methylated by means of this reaction.a-Methylglucoside, when methylated in methyl-alcoholic solution, yields a mixture of methyl glucose ethers ; the main constituent, trimethyl a-methylglucoside, which can be isolated by fractional distillation, is a viscid syrup; it boils at 167-170’ under 17 mm. pressure, exhibits dextrorotation, and has no action on Fehling’s solution. Complete methylation of trimethyl a-methylglucoside is readily effected with silver oxide in methyl iodide solution, and under these conditions, tetramethyl a-methylglucoside is obtained as a compara-tively mobile liquid boiling at 144-145O under 17 mm. pressure; it 193 is dextrorotatory, and has no action on Fehling’s solution. Tetra-methyl glucose, which is produced by hydrolysing the tetramethylated gliicoside with dilute hydrochloric acid, distils without decomposition at 182-185O under 20 mm.pressure, and solidifies slowly and crystallises from light petroleum in tufts of radiating needles,-melting at 81-83O ;it behaves like an aldose, reducing warm Fehling’s solution, giving tetramethylgluconic acid on oxidation, and reacting with phenylhydrazine in molecular proportion to form an oil, which is apparently a hydrazone. Tetramethyl glucose is dextrorotatory, but does not exhibit any notable multirotation. The production from a-met hylglucoside of a tetramethylgluconic acid, capable of forming a lactone, proves conclusively that the oxygen of the ring in the formula of the alkylglucosides is coupled with the y-, and not with the /3-carbon atom.A pentamethylated glucose, isomeric with the tetramethyl a-methyl- glucoside already mentioned, is produced when a solution of tetra-methyl glucose in methyl iodide is treated with silver oxide ;it boils at 124-127’ under 8 mm. pressure, crystallises in slender prisms melting at 42-43’’ and is lmorotatory. Methylfructoside behaves like the corresponding glucoside, and, when completely methylated, yields tetramethyl methylfructoside ; the two hydroxyl groups of acetone rhamnoside may also be methylated in a similar manner. Cane sugar, on methylation, yields a neutral oil, which has no action on Fehling’s solution until it is hydrolysed. The products of hydro-lysis are the abwe-men tioned crystalline tetramethyl glucose and an uncrystitllisable syrup, which is probably the corresponding methylated lzevulose.The facl that methylated cane sugar and methylated methyl- glucoside give on hydrolysis the same tetramethyl glucose proves that the constitution and linking of the glucose group of the di- saccharide is the same as that of the simple glucoside, and affords conclusive evidence, at least so far as the glucose half of the molecule is concerned, of the correctness of Fischer’s formula for cane sugar (Bey., 1893, 26,2404). 107. 6‘ Trimethyl a-methylglucosida and trimethyl glucose.” By T. Purdie and R. C. Bridgett. When a-methylglucoside, in methyl-alcoholic solution, is methylated by means of dry silver oxide and methyl iodide, the chief product is trimethyl a-methylglucoside.In preparing this compound, it was found that, in addition to the lower methylated derivatives, the tetra- 194 methylated glucoside was also produced, but only in small quantity, even when a large excess of the alkylating agent was used. The last hydroxyl group to be methylated undergoes the change more slowly than the others, and it seems therefore probable that the unmethylated hydroxyl of the trimethyl a-methylglucoside is that of the terminal primary carbinol group of the glucoside. The difficulty encountered in completing the methylation is, however, largely due to the loss of alkylating material caused by the production of dimethyl ether. Special experiments showed that the action between silver oxide and methyl iodide is much more rapid in the presence of methyl alcohol, and tbat the production of dimethyl ether is probably due, not to the direct interaction of the oxide and iodide, but to the methylation of alcohol.The specific rotation of the trimethyl a-methylglucoside, prepared by the authors was much in excess of that exhibited by the specimen referred to in the preceding note. The preparation of tetramethyl a-methylglucoside was also repeated, and the substance was found to be more dextrorotatory than the specimens previously examined. The dis- cordant results may be due to intramolecular rearrangement occurring under the action of methyl iodide, resulting in the production of varying quantities of the corresponding stereoisomeric P-glucosides.By hydrolysing trimethyl a-methylglucoside with dilute hydrochloric acid, trimethyl glucose was obtained as a viscid, colourless syrup, which distilled without appreciable decomposition at about 194’ under 9 mm. pressure. The substance, which was dextrorotatory and had the pro- perties of an aldose, reduced Fehling solution in the cold, and ammon- iacal silver nitrate on slightly warming; it appeared to react with phenyl- hydrazine, but the product, which was an oil, could not be made to crystallise. On oxidation with bromine water, it yielded an oil boiling at about 160’ under 11 mm. pressure. The numbers obtained by analysis, and from the estimation of methoxyl, agreed approximately with those required for trirnethylgluconic lsctone.The lactonic nature of the compound was confirmed by its behaviour on neutralisa- tion, and by thellgradual change of optical activity exhibited by its solution. 108. “Note on the corrosion of an Egyptian image.” By Henry Bassett, jun. An examination has been made of a bronze Egyptian image, about 6 inches higb, and having a hollow base filled with lead. This figure probably dates from 200 to 100 B.c., and now bears a mutilated in- scription which, according to Professor Flinders Petrie, reads as follows : Id Khonsu give life to ---- - ,son of ----p, born of 195 Saaenhap.” It was found in the delta of the Nile and is very exten- sively corroded, being covered by a thick, green coating, which in parts entirely replaces the original metal.The material for analysis was obtained from the base of the figure, and the following analytical results were obtained : cu ............ 50.65 per cent. CUCI, ............ 29.34 per cent. Pb ............ 6-74 ,, CUO ............ 46.10 ,, Sn ............ 2.94 ,, H,O ............ 11.07 ,, Fe ............ 0.15 ,, SnO, ............ 3.73 ,, Ni, Mn, &c. 0.11 ,, PbO ............ 7.26 ,, c1 ........... 15.71 ,, Fe,O, ............ 0.22 ,, SiO, (as sand) 1-14 ,, NiO, dzc.. ........ 0.14 ,, H,O ......... 11-97 ,, SiO, ............ 1-14 ,, (NH4)......... 0.11 ,, NH4Cl ......... 0.32 ,, 88.62 99.32 In the second table, the chlorine has been calculated as copper chloride, whilst the remaining copper and other metals are expressed as oxides.Traces of calcium were also Found, but the amount of sodium present was so small that it could only be detected by the flame test, If all the copper were present in the form of a basic chloride, CuCI2,3Cu0,3H,O, corresponding with atacam ite, this would require 26.84 per cent. CuCI,, 47-57 per cent. CuO, and 10.78 per cent. H,O. It will therefore be seen that the substance produced by corrosion is less basic than atacamite. The formation of this mineral during the corrosion of copper and bronze articles when buried in the soil has been shown by Berthelot to be very general (Compt. rend., 1894, 118, 768), but although the formation of this basic copper chloride is in most cases due to the action of the sodium chlorid; in the soil (Berthelot, Zoc.cit.), yet in the present instance, ammonium chloride may have played the most important part, since the latter salt was found in amount sufficient for estimation, whereas the former was not. 109. ‘‘ Contributions to the chemistry of the terpenes. Part I. The oxidation of pinene with chromyl chloride.” By (3. a. Hender-son,T. Gray, and E. Smith. When dissalved in carbon disulphide, chromyl chloride and pinene combine to form a solid compound, CloH1,,2Cr0,Cl,, which is decom-posed by water and yields a brown, oily liquid. This liquid, when distilled in steam, yields a quantity of resin and a volatile oil (Etard, Compt. rend., 1893, 116, 434). The authors have found that the oil 196 contains a saturated aldehyde, U,H,,*CHO, an unsaturated ketone, C,H,,:CO, and a small quantity of a chlorinated oxidation product of pinene.The aldehyde, which is a crystalline solid with a character-istic odour, melts at 32-33' and boils at 205-207" (under 755 mm. pressure) ;it is insoluble in water, but readily miscible with alcohol and ether. The sernicarbaxone crystallises in pearly leaflets and melts at 191". The aldehyde rapidly undergoes spontaneous oxidation in the air, being converted into a saturated acid, C,H,,*CO,H. This acid, which is obtained by oxidising the aldehyde with either boiling dilute nitric acid or aqueous potassium permanganate, crystallises in leafiets or flat prisms, and melts at 117' ;it is only sparingly soluble in cold water, but very readily so in alcohol, and volatilises slowly in steam.The lead salt and the silve~salt are obtained as white precipi- tates ;both are soluble in boiling water, but the latter very sparingly. The ketone is an almost colourless, aromatic liquid, which boils at 206-207" under 774 mm. pressure; its refractive index is 1.4760. The ketone at once decolorises permanganate, and combines additively with 1 mol. of bromine; it yields an oily oxime and a crystalline serniccwbaxone, which melts and decomposes at 226-228' ;on oxidation with sodium hypobromite, it gives bromoform and p-toluic acid. 110. "Some physical and chemical properties of strong nitric acid." By V. H. Veley and J. J. Manley. The investigations published by W.N. Hartley in the current number of the Transactions (p. 658) on the absorption spectra of nitric acid in various states of concentration have induced the authors to place ou record certain physical and chemical properties of nitric acid varying in concentration from 78 to 100 per cent. HNO, in continua- tion of their former work (Pror. Roy. Xoc., 1901, 69, 86, and Phil. Mag., 1902, [vi], 3, 118). Although such properties as density, contraction, refractive indices, and electrical conductivity vary uniformly with percentage concentra- tion from 78 to 92 per cent., yet from this point too100 per cent. there is an exceptional alteration in the variation, reaching a maximum at about 96 per cent., this strength corresponding with an acid which, according to Hartley's view, might be indicated by the formula 3H,N,06,H,N04 ( =95.9 per cent.HNO,). Acid having this concentration appears to form a kind of eutectic solution, and therefore presents an analogous, although not strictly parallel case to that of sulphuric acid containing 98 per cent. H,S04, which has been shown by R. Knietxsch (Ber., 1901, 34, 4069) to be a point of critical concentration as regards density, contraction (compare 197 Pickering, Trans.,1S90, 57,74), electrical conductivity, chemical re- activity, vapour pressure, and, to a less degree, capillarity and viscosity. As regards chemical properties, certain qualitative experiments have been made on the direct nitration of cotton by nitric acid of approxi-mately 100 per cent.concentration without the addition of sulphuric acid. 111. “Notes on ozone.” By J. K.H.Inglis. Experiments have been made in order to ascertain the molecular state of ozone when dissolved in acids. In the first place, it was found that the amount of ozone present in an acid solution could be determined by means of the following reaction: 0,+2HBr= Br, +0, +H,O, the bromine liberated being estimated by potassium iodide and sodium thiosulphate. In the second place, an investigation of the solubility of ozone in water showed that the solution could not be brought into equilibrium with respect to the gas, since some of the latter was always decom- posed on being bubbled through the solution, although the concentra- tion of the latter remained constant. Hence, the molecular state cannot be ascertained by means of the solubility relationship. Lastly, some experiments made on the action of ozone on hydrogen peroxide indicated that these substances acted slowly on one amther, inanganous sulphate behaving as a catalyser. ERRATUM. VOL. 19. No. 267. Page Line 147 9” for ‘‘ ammonia,” read “methyIamine.” * From bottom,
ISSN:0369-8718
DOI:10.1039/PL9031900179
出版商:RSC
年代:1903
数据来源: RSC
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