AUG UNIV, OF Edited by AND JOURNAL OF PHYSICAL SCIENCE James H. Gardiner, F.C.S.] (WITH WHICH IS INCORPORATED THE "CHEMICAL GAZETTE"). Established [in the Year 1859 Published Weekly. Annual Subscription, free by post £1 128. Entered at the New York Post Office as Second Class Mail Matter. Transmissible through the Post-United Kingdom, at Newspaper rate; Canada and Newfoundland at Magazine rate. THE CHEMISTS' YEAR BOOK, 1920. EDITED BY F. W. ATTACK, M.Sc.Tech., B.Sc. (Lond)., F.I.C. Assisted by L. WHINYATES, Assoc. M.S.T., A.I.C. An up-to-date compilation of Chemical, Physicochemical. Mineralogical, and Mathematical Tables, together with Technical Methods of Analysis. With Contributions (Revised for 1920 Edition) by C. F. CROSS, B.Sc. (Lond.), F.I.C., F.R.S., on "Cellulose and Paper.' R. E. CROWTHER, on "Photography." G. D. ELSDON, B.Sc., F.I.C., and A. D. HEYWOOD, F.I.C., on "Dairy Product." W. F. A. ERMEN, M.A. (Cantab.), on "Textile Fibres.'"' A. GROUNDS, B.Sc.Tech., on "Cement." S. E. HODGKINSON, A.I.C., on "Tobacco." E. HOPE, D.Sc., on "Alkaloids." W. MATHER, Assoc. M.S.T., A.I.C., on "Tannin Materials." J. W. MELLOR, D.Sc., on "Analysis of Clays, Firebricks, and H. MOORE, M.Sc.Tech., A.I.C., on "Fuels and Illuminants," E. H. RODD, D.Sc., on "Crystallography." E. J. RUSSELL, D.Sc., F.R.S., on "Agricultural Chemistry." J. R. WALMSLEY, Ph.C., on "Trade Names of Drugs." etc., etc. Also COMPLETE REVISION OF DATA IN PHYSICOCHEMICAL CONSTANTS SECTION, under the direction of G. BARR, D. Sc., of the National Physical Laboratory. Published by 1136 pp. Price (2 Vols.) Messrs. SHERRATT & HUGHES. 34, Cross Street, MANCHESTER. 21/- net (or post free, 21/9 inland, 22/- foreign). WHATMAN Note a few of our later specialities: .3 For use with No. 42-"ASHLESS." Double Acid washed and extremely close of texture. No. 50-Hardened by treatment with Nitric Acid. Very ough, it will resist great pressure, and SOLE MANUFACTURERS: W. & R. BALSTON, LTD., MEDWAY MILL, MAIDSTONE, KENT. FIND OUT ALL ABOUT OUR COMPLETE RANGE, FROM OUR REVISED BOOKLET AND FRICE LIST. In case of difficulty in obtaining Free Samples, write the Sole Mill Representatives- Phosphoric Acid 1500 WATER WHITE Acid Calcium Phosphate MANUFACTURERS: PRESCOTT & CO., HULME, MANCHESTER. Wires: "Corncrake," Manchester. News THE CHEMICAL NEWS. VOL. CXXI., No. 3146. EDITORIAL. THE following papers have been received for publication, and will be inserted as space permits :"The Constitutution and Structure of the Chemical Elements." "The Number 23." A mathematical proof is given that a mass of 23 (from which emanates one valence) takes a prominent part in the formation of all elements of greater, mass than itself. "The Five Main Principles in the Constitution and Structure of the Chemical Elements." This paper is chiefly concerned with the fifth principle, viz. :-Each of the heavier elements is formed by the union of simpler elements (which are indicated in each case by mineralogical and chemical facts combined.) A proof is given that the observation of this principle is not due to a series of accidents. "The Constitution and Structure of the RadioActive Elements." It is shown that there is a great probability that hexadic titanium is the main constituent of radio-elements. There is no claim that this particular deduction is proved to be true, because there are not sufficient facts available to make possible the application of the theory of mathematical probability. (By Hawksworth Collins, Stubbington House School, Fareham, Hants.). DISTRIBUTION OF ACETIC ACID BETWEEN WATER AND CHARCOAL. By ALWYN PICKLES. ACETIC acid solutions of different normality were used, 100 cc. at a time. Charcoal was added, 5 grms., and equilibrium between the two phases obtained. Complete equilibrium took several hours, but most of the sorbtion took place very rapidly. The concentration of the aqueous phase was obtained by filtering off charcoal and titrating known volumes of the filtrate, with N/10 caustic soda. Knowing the real density of the charcoal used and original normality of acid, the concentration per cc. of charcoal readily followed. Experiments were done with several kinds of charcoal in varying states of division. The effect of temperature was also studied. Concentrations are given in mols. per cc. I. Fruit Stone Dust. Density 170. (1) More acid is removed relatively from dilute solutions. (2) Concentration per CC. of charcoal depends on the kind of charcoal and on its state of division. In the preceding cases, the acid and charcoal had been in contact at least 24 hours at 10°-12° C. Hence, surface and interior effects may be assumed as complete and that equilibrium existed between polymerised and simple molecules. Increase of temperature disturbs this equilibrium, the tendency being for polymerised molecules to break down into simpler ones. The acid concentration of charcoal therefore diminishes. If, however, acid and charcoal are only together for a short period, increase of temperature increases the acid concentration in charcoal to a slight extent. This is due to the hastening of the interior effect otherwise not complete. Animal charcoal is an exception. It removes the acid almost entirely by adsorption. Though such charcoal is porous in the mass through presence of such things as calcium phosphate, the actual carbon particles have not that complex structure which characterises wood charcoal. Since the charcoal and aqueous phases are immiscible it is instructive to apply the distribution equation. C (Charcoal) 10 50° N = 2'1 n=2'0 12° 30° 50° K=0.220 K=0 200 0'209 12° 3 238 251 262 30° 50° III. 2 155 160 166 214 167 129 Birch Dust. 12° 154 136 115 I 68 77 80 4 C (Charcoal) 10 30° 23 26.4 26.4 15 16.8 50° 12 30° 17 167 280 179 168 224 123 112 The value for n given in Thorpe's "Dictionary of Applied Chemistry," vol. ii., Colloids, is 2:35. This is evidently an average value. The above work has been repeated by a class of chemistry students and the above results confirmed within a very small margin. 50° A STUDY OF DOLOMITES. By C. L. HARDING, J. B. SHUMAKER, and A. W. ROTHROCK. DEODAT DOLOMIEU was born in Dolomieu, France, June 23, 1750, and died November 16, 1801. In infancy he was created a Knight of Malta. He seemed precocious in many directions. When nineteen years of age he quarrelled with a companion and killed him. He was condemned to death for the crime, but after nine months' imprisonment, he was pardoned on account of his youth. He early became interested in geology and mineralogy, and wrote some important treatises on his favourite subjects, especially while residing in Metz, the interesting old capital of Lorraine. He discovered dolomite while making an extended tour and observations among the Alps in 1789-90. The mineral was first described by him in 1791, and the name was bestowed upon it in honour of the discoverer. The dolomite mineral and rock are important from both a theoretical and practical standpoint. Much work has been done upon them, and the mineral can be artificially produced by a number of different methods. Marignac was probably the first to make it artificially. His method was to heat calcium carbonate and a solution of magnesium chloride to 200° under a pressure of fifteen atmospheres. In a closed gun barrel J. Dorocher heated porous limestone and dry magnesium chloride to about 1200°. The vapour of the chloride permeated the porous limestone, which was partially transformed into dolomite. In a similar way, it has been suggested, the heat in the neighbourhood of volcanoes may produce the mineral and rock. One of the simplest methods was devised by C. Sainte-Claire Deville. He saturated chalk with a solution of magnesium chloride and heated the mixture upon a sand-bath. More or less of the materials change into dolomite. By heating powdered calcite with magnesium sulphate to 200° in a closed tube, von Morlot obtained a mixture of dolomite and calcium sulphate. It has been suggested by Haidinger that this reaction accounts for the frequent association of dolomite and gypsum. T. Sterry Hunt conducted a long series of experiments on the precipitation of calcium and magnesium carbonates, from which he reached the conclusion that dolomite is simply a chemical precipitate. This view has not been generally adopted. In more recent times, 1909, G. Linck published a report of a new method of making dolomite. He mixed solutions of magnesium chloride, magnesium sulphate, and ammonium sesquicarbonate, and then added a solution of calcium chloride. An amorphous precipitate came down, which on gently heating for some time in a closed tube became crystalline. This had the composition and optical properties of dolomite. Linck believes that his experiment explains the formation of marine dolomite, and that the ammonium salt necessary can easily result from the decomposition of organic substances. |