Many substances which are precipitated from aqueous solution are capable of emulsifying oils, and, by adjusting the amount of oil in the emulsion, the latter may be obtained of the same density as the liquid. By determining the density of this liquid, the density of the oil, and that of the precipitate in the anhydrous conditions, and by ascertaining the weight of oil required to float a given weight of precipitate in two liquids of different densities, the weight of water combined with the anhydrous precipitate may be determined. The precipitate selected was the compound 10CuO, SO3, CaSO4, Na2SO4, which is of uniform composition when thrown down by adding lime-water to copper sulphate in the presence of varying quantities of sodium sulphate. The amount of water combined with it was found to be about 42H2O. It was also ascertained that the water possessed the same specific gravity of ice, as in the case of the water of crystallisation of most hydrated salts. DISCUSSION. The PRESIDENT called attention to the fact that Dr. Chichester Bell had, more than ten years ago, made experiments on the velocity of sound in melted ice at +0.5°, and in cooled water at the same temperature. The velocities appeared to differ. Experiments by Dr. Wilsmore, unpublished, on the density of melted ice, and of cooled water, were indecisive, owing to the lapse of time before an accurate density could be determined. He also reminded Mr. Pickering that Playfair and Joule had concluded from their experiments that "water of crystallisation" has the same molecular volume as ice. *8. "Studies of Dynamic Isomerism. Part VIII. The Relationship between Absorption Spectra and Isomeric Change. Absorption Spectra of Halogen, Nitro-, and Methyl Derivatives of Camphor." BY THOMAS MARTIN LOWRY and CECIL HENRY DESCH. The band noted by Baly and by Hartley in the ultraviolet absorption spectrum of camphor at a concentration of N/10 appears also in the spectrum of 8-bromocamphor ; in both cases the band is weakened by diluting to N/100, but is restored by the addition of alkali. A similar band of rather greater intensity is seen in the spectrum of a-bromocamphor at a concentration of N/100; as this band is developed by neutral solutions in which the a-bromo-compound is stable, and is only slightly intensified when a condition of equilibrium between isomerides is set up by the addition of alkali, its appearance cannot well be associated with the occurrence of reversible isomeric change. No marked change is seen in the absorption spectrum of a-bromo-camphor when a halogen is introduced into the B- or -position, but the band is no longer developed when the second a-hydrogen atom is displaced by a halogen or by a nitro-group; it may therefore be associated with the presence of a displaceable hydrogen atom in the group -CHX CO-, although not dependent on any actual transference of the atom; a'-bromo-a-methylcamphor appears, however, to produce a shallow band. The weak band of nitrocamphor is greatly intensified by alkalis, but does not appear in the spectrum of the anhydride derived from the pseudo-form; it is therefore dependent on the presence of a displaceable hydrogen atom rather than on the occurrence of a pseudo-nitrostructure. The 3- and -bromo-derivatives behave like nitrocamphor, but the a-halogen derivatives, which do not undergo isomeric change in solution, produce no absorp; tion band. Nitrocamphane does not give rise to a band either alone or in presence of alkali. 9. "The Relationship between the Constitution and the Absorption Spectra of Pyridine and various Derivatives." BY JOHN EDWARD PURVIS. 81 The absorption bands of 3:5-dichloropyridine, two isomeric trichloropyridines, two isomeric tetrachloroaminopyridines, a-picoline and several of its derivatives, 2:4:6trimethylpyridine and several of its derivatives, and chlorolutidine have been investigated. The results showed that: (1) The general effect of introducing atoms or groups of atoms into the nucleus is to increase the persistence of the absorption band as well as to shift it towards the red end of the spectrum, whilst when they are introduced into the side-chains they generally decrease the persistence. (2) The weighting of the nucleus does not, however, always mean that the absorption band is shifted towards the red end. The type and the spatial position of the introduced atoms or groups are factors in determining the absorption. (3) In isomeric substances, the spatial positions of the substituting atoms in the nucleus are of considerable importance in influencing the position and the persistence of the absorbed rays. (4) The substitution of atoms in the side-chains does not exert the same marked influence as when they are substituted in the nucleus. (5) The addition of hydrochloric acid to 2:4: 6trimethylpyridine and a-picoline (as well as to pyridine and lutidine) exerts a marked influence on the vibrations of the nucleus, and the effect is very similar to that produced when chlorine atoms are introduced into the nucleus. Considerations on the influence of the changing valency of the nitrogen atom and other conditions in explanation of these facts were discussed. IO. "The Action of Mustard Oils on the Ethyl Esters of Malonic and Cyanoacetic Acids." Part II. By SIEGFRIED RUHEMANN. Like the latter, the yellow cyclic com pound (I.) (and also II.) condenses with aldehydes with the formation of compounds of the general formula C(CHR) CO S It was found that the same \C(:N Ph)--Ċ (CN) CO2Et products were formed from the colourless compound, and this fact led to the view that both specimens of I. were identical. The author was able to verify this conclusion. II. "The Interaction of Hydrogen and Chlorine." By DAVID LEONARD CHAPMAN and PATRICK SARSFIELD MACMAHON. The authors have shown that the statement of Bunsen and Roscoe, that the rate of photochemical action between chlorine and hydrogen in a mixture containing equivalent amounts of these gases is reduced by the addition of a small volume either of hydrogen or chlorine, cannot be substantiated. Hydrogen and chlorine prepared by the electrolysis of concentrated hydrochloric acid do not possess the alleged inhibitive influence if sufficient precautions are taken to exclude air. It is considered likely that the hydrogen used by Bunsen and Roscoe contained oxygen. This is the more probable, as the gas employed by them was prepared by the electrolysis of dilute sulphuric acid. 12. "Nitrogen Chloride." By DAVID LEONARD CHAPMAN and LEONARD VODDEN. The authors have shown by a direct analysis that the amount of hydrogen contained in the vapour of nitrogen chloride prepared by the action of chlorine on a neutral solution of ammonium chloride is inappreciable. In harmony with this result, the ratio of nitrogen to chlorine is = 123.71). The evidence from found to agree very closely with the formula NC13. | zoyldiphenylethylene (M. Gattermann's conclusion that the freshly-prepared chloride a consideration of their refractive power is applied to contains hydrogen which can only be replaced by the determine the constitution of the a diketones and s-diacylcontinued action of chlorine is therefore called in question. ethylenes. Marked similarities are shown in the behaviour A method by which the ammonium chloride resulting of these two classes of compounds. from the hydrolysis of nitrogen chloride with hydrochloric acid can be isolated without the aid of a reducing agent was described. The method affords the first entirely STANLEY KIPPING. B-Methylhydrindone, C6H,<H2>CHMe (Kipping and Clarke, Trans., 1903, lxxxiii., 913), is slowly oxidised on exposure to the air, giving a mixture of compounds from which acetic, phthalic, and benzylmethylketone-o-carboxylic acid, CH3 CO CH2 C6H4CO2H, may be isolated; a small amount of a neutral compound, melting at 211°, is also present in the crude oxidation product. It is suggested that the ketonic form of methylhydrindone (compare Kipping, Proc., 1902, xviii., 34) first undergoes change to the enolic modification, which then combines directly with a molecule of oxygen in much the same way as unsaturated compounds combine with a molecule of ozone; this additive product is then decomposed by water, giving benzylmethylketone-o-carboxylic acid, and by similar processes the latter is oxidised to phthalic and acetic acids. 14. "A Glucoside from Tephrosia purpurea." (Preliminary Note). By GEORGE CLARKE, jun., and S. C. BANERJEE. 17. "The Transformation of Aliphatic Nitriles into Alicyclic Imino-compounds." (Preliminary Note). By JOCELYN FIELD THORPE. For some time past experiments have been in progress having for their object the study of the conditions under which aliphatic dinitriles having the nitrile groups separated by two, three, four, &c., carbon atoms pass into the corresponding alicyclic imino-compounds. Preliminary experiments indicate that there is a greater tendency to form a three-carbon ring in this manner than a ring of four carbon atoms, but that the cyclopentane ring is produced with most remarkable ease. Thus, during some experiments on the formation of the cyclopropane ring by the interaction of ethyl sodiocyanoacetate and ethylene dibromide, Carpenter and Perkin (Trans., 1899, lxxv., 921) isolated, as a by-product, a substance which melted at 119.5°, and to which they assigned the formula CN CH2 CH2 CH2 CH(CN) CO2Et (ethyl ad dicyanovalerate), owing to the fact that it yielded adipic acid on hydrolysis with alkaline hydrolysing agents. It is now found that this substance is ethyl 2-imino-3cyanocyclopentane-1-carboxylate (I)., and that it is immediately converted by the action of cold concentrated hydrochloric acid into ethyl 3-cyanocyclopentane-2-one-1carboxylate (II). :— NH:C CH(CO2Et) CH I. CO CH(CO,Et)•CH, Tephrosia purpurea, Pers. (nat. ord. leguminosæ), a small woody annual, grows luxuriantly during the monsoon in many waste tracts of the United Provinces of Agra and Oudh. The leaves yield a crystalline glucoside on ex- Ethyl 2-imino-3-cyanocyclopentane-1-carboxylate can be traction with either ethyl alcohol or acetone, and subse-produced in almost theoretical yield by the interaction of quently treating the evaporated extract with water and ethyl sodiocyanoacetate and ethyl 1-cyanocyclopropane-1light petroleum to separate tar. The yield from one ex- carboxylate in alcoholic solution, the sole products of the traction is approximately 2 per cent on the dried leaves. reaction being the sodium compound of the imino-comThe glucoside melts and decomposes at 180-185° (uncorr.), pound and ethyl carbonate; the equation representing the and on hydrolysis with dilute sulphuric acid yields quercetin initial and final products of the reaction is therefore as and dextrose. It appears, therefore, to be identical with follows:osyritrin (A. G. Perkin, Trans., 1897, lxxi., 1134). CH2 15. "Note on the Constitution of the Carboxyl Group.” By IDA SMEDLey. From a consideration of the physical and chemical proO perties of the carboxylic acids, the constitution .CII OH is suggested for the carboxyl group as better representing its physical and chemical behaviour. 16. "The Relation between the Chemical Constitution and Optical Properties of the Aromatic a- and y-Diketones." By IDA SMEDLEY. Yellow s-dibenzoylethylene (m. p. 111°) was prepared by condensing benzoylformaldehyde with acetophenone in the presence of acetic anhydride. This compound is identical with that obtained by Paal and Schulz (Ber., 1900, xxxiii., 3784) by the action of heat on dibenzoylmalic acid. From a consideration of the solubility, melting point, refractive power, and colour of the cis- and transisomerides, the yellow form, which has the greater solubility, lower melting-point, and greater refraction, is regarded as the cis-isomeride, and not the trans-form as suggested by Paal and Schulze. These two forms furnish the first instance described of a marked difference in the refraction of cis- and trans-isomerides. The molecular refractions of the following compounds were measured :-Phenyl methyl diketone (Ma 4132), benzoylformaldehyde (Ma 36.99), cis-dibenzoylethylene (m. p. 111°; 73.96), trans-dibenzoylethylene (m. p. 134°; 7184), cis-dibenzoylphenylethylene (Ma 99:57), fis-dibenzoyldiphenylethylene (M 122176), trans-diben Ma Ma = = = = CN CHNA CO2Et+CO2Et C(CN) |. + EtOH → NH:C `CNa(CN)—. CH2+CO(OEt)2. sodiomalonate is substituted for ethyl sodiocyanoacetate A similar condensation product is obtained when ethyl in the above equation. The investigation of the properties of these cyclic ketones is in progress. 18. "Action of Alcohols on Metallic Calcium.” By FREDERICK MOLLWO PERKIN and LIONEL PRATT. When calcium is added to alcohols reaction ensues and the alkyloxide, Ca(OAlk)2, is produced (Proc., 1907, xxiii., 304). The reaction, however, is generally slow, but is Calcium hydride reacts more greatly facilitated by heat. readily than metallic calcium, but the product is less pure than when the metal is employed, owing to impurities in the calcium hydride. Calcium ethoxide is soluble in ethyl alcohol, and crystallises with two molecules of alcohol of crystallisation. Other alkyloxides are not so readily prepared, owing to their insolubility in the alcohols. Calcium ethoxide has been employed satisfactorily for organic condensations in place of sodium ethoxide. 19. "The Condensation of Oxymethylenecamphor with Primary and Secondary Amino-compounds." By WILLIAM JACKSON POPE and JOHN READ. On condensing externally compensated a-phenylethylamine with d-oxymethylenecamphor, two stereoisomeric products are obtained, one from each of the optically CHEMICAL NEWS, Feb. 12, 1909 Transport of Ions. 83 active components of the primary base; a method is thus | recently at Waltham Abbey. The nitration is effected in indicated for ascertaining whether a particular primary amino-compound is or is not externally compensated. The two products exhibit marked mutarotation, and this is attributed to their conversion in solution into isodynamic mixtures. d-Oxymethylenecamphor itself and its condensation products with aniline, p-toluidine, and B-naphthylamine exhibit mutarotation in various solutions, and this is again attributed to isodynamic change. 20. "Note on the Variation in the Catalytic Activity of Mineral Acids with Changes in their Concentration." By ARTHUR LAPWORTH. Several recent investigations (Senter., Trans., 1908, xci., 467; Stieglitz, Am. Chem. Journ., 1908, xxxix., 29 et seq.; Acree and others, Ber., 1908, xli., 3214 et seq.) suggest that during certain changes, in which electrolytes are concerned, not only simple and complex ions are directly concerned, but that intramolecular changes in, and interactions between, non-ionised substances may occur, and sometimes even to the extent of being a necessary part of the process. The author recently referred to such a possibility in the case of esterification as accelerated by an acid (Trans., 1908, xciii., 2196, 2197), inferring that the disproportionate increase in the velocity with increase in the amount of mineral acid may possibly be due to a secondary reaction of this nature. It is necessary to state that the discussion applied only to those cases where no relatively powerful base is present in such small quantity that this decreases rapidly on addition of mineral acid, as might conceivably be the condition in alcohol containing only a very little water; the general case, however, comes under the discussion mentioned, and, as has long been recognised, is doubtless intimately connected with neutral salt action. Attention must also be drawn to the fact that the exd2(H2) pression for - (not d2 (H®) ; loc. cit., p. 2197), dA dA which indicates the direction of change in relative quantity of non-ionised compounds with alteration in the amount of catalyst, is always positive, this not being limited even by the condition suggested. 21. "The Condensation of Dimethyldihydroresorcin with Ethylamine." By PAUL HAAS. By the action of nitrous acid on the condensation product of ethylamine with dimethyldihydroresorcin, a compound of the constitution CMe2<CH2 CH2C(NE)>C: NOH is produced. -CO This substance crystallises from water with two molecules of the solvent, and has a very intense carmine colour; when dried in a vacuum it becomes anhydrous, and is then dark blue. SOCIETY OF CHEMICAL INDUSTRY. Dr. J. LEWKOWITSCH in the Chair. "Gun-cotton and its Manufacture." By Colonel Sir FREDERIC L. NATHAN, R.A. Gun-cotton was discovered by Schönbein in 1846. Its manufacture was worked out by Von Lenk and improved by Abel. The raw material is cotton-waste; this is immersed in small quantities for a few minutes in a mixture of nitric and sulphuric acid, the excess acid squeezed out, and nitration completed in earthenware pots. The acid is removed by centrifugalising, the gun-cotton drowned in water, and purified by boiling, pulping, and washing. The nitration process has been modified of late. In one case the nitration is completed in the original dipping-pan, in another it takes place in the centrifugal itself. A third process, th Thomson displacement process, was introduced shallow circular earthenware pans; when it is finished, water is run slowly into earthenware plates placed on top of the cotton, and a cock at the bottom of the pan is opened for the waste acid to run out at the same rate as the water runs on. The water removes the acid from the gun-cotton which is ready for boiling. This process has many advantages over the others. The paper describes fully all the operations in the manufacture of gun-cotton. THE RÖNTGEN SOCIETY. AT the February meeting of this Society Dr. A. H. PIRIE initiated a Discussion upon the question of the Transport of Ions. He said that the first to use ionic medication in this country was Benjamin Ward Richardson, but that it was only within the last ten years that the method had possible modes of conduction of electricity had been divided become popular in the treatment of certain diseases. The by Sir Oliver Lodge into the birdseed method, the bullet method, and the fire-bucket method. In the case of the introduction of ions into the human tissues, the first of these methods was the one which had to be considered. As a bird carried a seed with it and only dropped it when it had reached its destination, so an ion carried its electric charge-the smallest known portion of electricity-and dropped it when it reached an electrode. Chemical, toxic, antiseptic, and medicinal actions of electrolytic substances were almost exclusively ionic in nature. Toxic and pharmacological actions depended essentially on ionic groups, and it was much more important therapeutically to consider the ionic group than the atomic or molecular. As an example, he took phosphides and phosphates. The first were toxic, the second were not. Phosphides, though united to cations which had different actions, all possessed the same toxic and therapeutic effects. The phosphorus ion was all important in the phosphides. The phosphate molecule contained phosphorus in the same proportion as did the phosphide, but the phosphorus in the phosphate was locked up in the complex ion, PO4, the properties of which were quite different from the phosphorous ion of the phosphides. The same could be said of sulphates and sulphides, and, in general, of all ions. When a current passed through the human body there was an exchange of ions between the surfaces of contact of dissimilar chemical compounds. The anions in the depth of the tissues moved towards the positive pole, and the cations moved towards the negative pole, and there was thus a change in the chemical composition of the deep tissues of the body. After demonstrating the manner in which different ions entered the skin, Dr. Pirie said that the chief disadvantage os using ions in medicine was the fact that it was only possible for the patient to bear a comparatively small current with any degree of comfort. Usually this amounted to about 1 milliampère per square centimetre. In the subsequent discussion Dr. LEWIS JONES read a letter he had recently received from Professor Leduc, of Nantes, the pioneer of recent ionic medication, in which the French investigator pointed out a curious effect he had lately obtained on applying an electrode of metal to a surface of gelatin. A film of gelatin, impregnated with ferrocyanide of potassium, is taken upon glass, and metallic electrodes, which may be of copper, iron, or zinc, are laid down side by side at convenient distances from this conducting film. A migration of ions then takes place, forming a precipitate of ferrocyanide of copper or iron or zinc, as the case may be. But, strangely enough, the current does not pass evenly, but shows a tendency to concentrate around the edges of the electrode. Thus the gelatin surface immediately under the electrode does not receive the same share of current as the portions corresponding to the edges. The ferrocyanide of copper marks the distance that the copper ions move during the experi ❘ment, and several slides were shown in which a greenish patch in the gelatin was seen to be surrounded by a ring | for instance, those of solanaceous drugs, have also been of brown, due to the ferrocyanide. The gelatin immediately under the electrode remained green, while the parts near the periphery of the electrode became coloured brown. NOTICES OF BOOKS. added. The third part of the book on Reagents and Microtechnique has been extended, and a few further additions have been made. The best proof of the value of the work for students of botany and for drug analysts is to be found in the fact that it has been necessary to produce a third edition within a very short time after the appearance of the second, which again followed quickly on the first. MISCELLANEOUS. Quantitative Experiments in General Chemistry. By JOHN Anniversary Dinner.-It has been decided by the Royal Institution.-On Thursday next, February 18, lectures at the Royal Institution on "Problems of Geoat 3 o'clock, Dr. Hans Gadow will begin a course of three graphical Distribution in Mexico." The Friday Evening Discourse on February 19 will be delivered by Sir Henry Cunynghame on "Recent Advances in Means of Saving Life in Coal Mines." chemical combination. Metallic Alloys; their Structure and Constitution. By MEETINGS FOR THE WEEK. MONDAY, 15th.-Royal Society of Arts, 8. (Cantor Lecture). "Modern Microscopical, 8. "On a German Silver Powell Portable Microscope made in 1850," by "Problems of Geographical In this book, which is based upon the lectures on alloys METROPOLITAN BOROUGH of DEPTFORD. APPOINTMENT OF PUBLIC ANALYST. The he Council of the above Borough invites applications for the position of PUBLIC ANALYST for the Borough from gentlemen possessing the necessary qualifications and able to furnish such proof of competency as may from time to time be required by the Local Government Board. The appointment will be for twelve months from March 31st, 1909, and will be subiect to the approval of the Local Government Board. The fee to be paid for each analysis will be at the rate of Ten Shillings per sample, which is to include the provision of the necessary laboratory, apparatus, and appliances. Not less than 300 samples will be submitted during the year. Applications, accompanied by copies of not more than three recent testimonials, and giving particulars of Certificates and Diplomas possessed by the applicant, must be made upon forms to be obtained at the Town Hall, New Cross Road, S.E., and must be returned to the undersigned not later than Saturday, FEBRUARY 27th, 1909. will disqualify candidates. Canvassing members of the Council, either directly or indirectly, (Signed) VIVIAN ORCHARD, Town Clerk. Town Hall, New Cross Road, S.E., February 11th, 1909. |