Some suggested Cross Relations between Extreme The Valencies of Zinc, Cadmium, and Mercury. A Periodic Classification of the Elements based upon Operative in certain Chemical Changes, and (ii.) in certain Primary Forms of Matter. The Study of some Special Groups, or Classifications A Note on the Valencies of Vanadium and Bismuth. A Note on the Theory of the Atom, based upon Ex- hemistry." - Chemist and Druggist, May 3, 1913. monumental character."-Journal of the Society of Dyers and Colourists, June, 1913. The Absorption of Light by Water changed by the presence of CORRESPONDENCE.-Chromate and Bichromate of Potassium or Sodium.-Destruction of Roots of Trees The CHEMICAL NEWS from commence- ment. Volumes or Numbers. State condition, price, &c.- person who can show that there is something radically wrong with the proof that the valencies of carbon are unequal, as demonstrated by 188 molecules in two books (price is. 3d. each post free) which can be obtained from Messrs. MORTON and BURT, Edgware Road, N.W. The proof can only be upset by the production of other values for the relative volumes of the six elements concerned, and by the demonstration that the results are more exact than those given. Results to be sent to the Author, HAWKSWORTH COLLINS, care of and sizes of Platinum Utensils and Apparatus for Chemical and Physical purposes. All our utensils are hammered to shape, tested, and finished in the best manner. All kinds of Platinum scrap bought for cash or taken in exchange for new.-DERBY and CO., Ltd., Olty Chambers, Ichthyol-Substitute. CRUDE OIL July 18, 1913 For the manufacture of Ichthyol-like preparations. } [Address" EBOFAM," CHEMICAL NEWS Office, 16, Newcastle Street, Farringdon Street, London, E.C. UNIVERSITY COLLEGE, NOTTINGHAM. Wanted by a Chemistry Student, temporary DEPARTMENT OF CHEMISTRY. Head of the Department-F. S. KIPPING, Ph.D., D.Sc., F.R.S. Occupation during vacation.-Address, A. G., 59, Wroughton Students are prepared for the Examination for Wanted, Junior Assistant with knowledge of the B.Sc. Degree (Honours in Chemistry) of London University, and also for the Intermediate and Final Examinations for the Associateship of the Institute of Chemistry. Fees, £6 per Term. All information and Prospectus from the Registrar,— Steel Analysis.-State age, experience, and salary required to CHIEF CHEMIST, Frodingham Iron and Steel Co., Ltd., Scunthorpe, Lincs. PURE CULTIVATION OF YEAST. Courses for beginners, as well as for Advanced Students in Manuals: ALFRED JORGENSEN, "Micro-organisms and Fermenta- Further particulars on application to the Director- Copenhagen Y., Denmark. SULPHUROUS ACID and SULPHITES. W. & G. FOYLE, 121/3, Charing Cross Rd., London, W.C. Liquid SO2 in Syphons, for Lectures, &c. JUL 29 113 CAMACI MARS Solubilities of the Rare Earth Salts. THE CHEMICAL NEWS. VOL. CVIII., No. 2799. SOLUBILITIES OF THE RARE EARTH SALTS OF BROMO-NITRO-BENZENE-SULPHONIC ACID (1:42).* By S. H. KATZ and C. JAMES. HOLMBERG (Chem. Centr., 1906, ii., 1595) used metanitro-benzene sulphonic acid very successfully for the separation and purification of neodymium. Derivatives of this acid therefore gave promise of being useful in work on the rare earths. Bromo-nitro-benzene sulphonic acid (124) was prepared by the method of Limprecht (Ber., viii., 456). The lanthanum, cerium, and yttrium salts of this acid were 25 other acid material besides the bromo-nitro-benzene sulphonic acid (1:4: 2) was formed. The latter crystallised well from a boiling, saturated, aqueous solution. A pure material was obtained by a series of fractional crystallisations of the crude acids. The yield was about 30 per cent. Salts of lanthanum, cerium, yttrium, and ytterbium were prepared. All crystallised nicely from solution, forming salts only very faintly tinged with the yellow colour of the acid. The properties were such that this acid was seen to offer opportunity for a definite comparative study of the properties and solubilities of a series of rare earth salts. The compounds of the acid with yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, erbium, thulium, and ytterbium were prepared and crystallised from solution. The first crop of crystals only were used in this work. Composition was found by determination of water of crystallisation by heating the air dry crystals to 200°, and by determination of R2O3 by means of the oxalate precipitation and ignition. In the case of praseodymium the oxalate was titrated with a standard KMnO4 solution. The results are given in Table I. SOLUBILITIES OF RARE EARTH SALTS OF BROMO NITRO RENZENE SULPHONG ACO (1:4.2) Atomic Weights prepared and found to be very soluble. By spontaneous evaporation yellow warty crusts finally formed, which were useless for crystallising. Bromo-nitro-benzene-sulphonic acid (1:4:2) was prepared by the method of Augustin and Post (Ber., viii., 1559). In sulphonating the bromo-nitro-benzene it was treated with two and one half times its weight of sulphuric acid containing 40 per cent free SO3 at 100, until the mixture dissolved completely in water, which required about twenty-four hours. The product was treated with BaCO3 and excess of soluble barium then removed by treating with the proper amount of H2SO4. Considerable • Contribution from the Chemical Laboratory of New Hampshire College. In the case of the erbium, thulium, and ytterbium compounds, which contained twelve molecules of water of crystallisation, the water could not be determined, because at the temperature used for the other salts these were charred, while at a lower temperature the water was not all evolved. The colours of the salts of praseodymium, neodymium, samarium, erbium, and thulium were not modified noticeably by the colour of the acid radical. The compounds containing eight molecules of water of crystallisation formed needle-like crystals; those containing ten molecules, thin orthorhombic plates, and those containing twelve molecules less regular piates and needles. The solubilities were determined after allowing equil. ibrium to become adjusted by rotation in a thermostat TABLE I. THE ABSORPTION OF LIGHT BY WATER H2O (per cent). R2Og (per cent) | CHANGED BY THE PRESENCE OF STRONGLY 12.66 10'07 Cal. Found. Cal. Found. Y (C6H3Br.NO2.SO3)3.10H2O 16:29 1590 15.98 La (C6H3Br.NO2.SO3)3.8H2O 12.80 12.80 12.90 Ce (C6H3Br.NO2.SO3)3.8H2O 12.78 12.60 12.60 Pr (C6H3Br.NO2.SO3)3.8H2O 12.78 13:05 12.78 Nd (C6H3Bг.NO2.SO3)3.8H2O 12.74 12.82 Sa (C6H3Br.NO2.SO3)3.10H2O 15:35 15:01 14'96 Eu (C6H3Br.NO2.SO3)3.10H2O 15:34 14 98 15°33 Gd (C6H3Br.NO2.SO3)3.10H2O 15:27 14 93 Er (C6H3Br.NO2.SO3)3.12H2O Tm (C6H3Bг.NO2.SO3)3.12H2O Yb (C6H3Br.NO2. SO3)3.12H2O 14'99 Mols. anhydrous salt 0.1178 NEW EVIDENCe for the SolVATE THEORY OF SOLUTION. 10*16 10:13 THE use of the radiomicrometer in studying the absorption Per cent anhydrous salt. 5'739 4'771 5'559 O'1112 5.730 0.1322 6.762 Sa (C6H3Br.NO2.SO3)3 0'1427 7.272 Eu (C6H3Br.NO2.SO3)3 Gd (C6H3Br.NO2.SO3)3 Er (C6H3Br.NO2. SO3)3 Tm (C6H3Br.NO2.SO3)3 O'1214 Yb (C6H3Br.NO2.SO3)3 O'1397 6.379 kept constant at 25°. The results in Table II. are averages of duplicates. The solubilities plotted against atomic weights are shown graphically in the accompanying diagram. It is seen that, with change in the water of hydration, there is a change in direction of the solubility curve, which amounts to a reversal of the slope. The phenomenon shown may be compared to that producing the change in the general direction of the temperature-solubility curve of a single salt forming various molecular compounds with water at different temperatures. That is, with a break in the general direction of the solubility curve there is a change in the nature of the compound. Work on the separation of various rare earths by crystallising salts of bromo-nitro-benzene sulphonic acid (142) is now under way in this laboratory. Durham, N.H. Two Characteristic Colour Reactions of Phenylalanine.-L. Chelle.-To identify phenylalanine a little of the substance is dissolved in 4 cc. of H2SO4 in the cold and the solution is divided into two portions. One drop of formol is added to the one, when an orange colouration, rapidly turning brown, is produced. One drop of an alcoholic solution of paraldehyde is added to the other, and after ten minutes a lemon colouration is produced. After an hour it exhibits a green fluorescence. By these two reactions one milligrm. of phenylalanine can be detected. The second test is most useful for quantitative determination, which can be performed by comparing the colourations obtained after one hour.-Bulletin des Travaux de la Sociét de Pharmacie de Bordeaux, vol. liii., March, 1913. It is obvious that the above is a very remarkable fact. The dissolved substance could not have less than no absorption of light, the assumption having been made, up to this time, that in an aqueous solution the water present absorbs just as much as pure uncombined water. The above result is directly at variance with everything that was known at the time. It became at once obvious that we could not measure the absorption spectrum of a solution, subtract from it the absorption due to water, and conclude that the remainder was the absorption due to the dissolved substance, since the water in the solution has very different absorption from an equal amount of pure uncombined water. We then carried out a number of experiments in cells whose depths could be easily and accurately adjusted, with different substances, in the following manner :-We measured the absorption spectra of a number of different substances. We then measured the absorption spectra of water having the same depths of layer as the water in the solutions. We found that for certain substances the pure water was more opaque than the solutions, and for other substances the water was more transparent. The percentage transmission, that is, the deflection of the radio This investigation was carried out with the aid of a Grant generously awarded by the Carnegie Institution of Washington to H C. Jones. From the Americad Chemical Journal, xlix., No. 4. |