It resembles a scheme proposed by Harkins (see, e.g., Hopkin's Chemistry of the Rarer Elements, reviewed in The Chemical News, 1924, CXXVIII, 369), and Nodder states that his scheme is suited for use as a chart. Corresponding radii of the primary and secondary spirals are parallel to one another. The dotted lines are intended to recall the resemblances between lithium and magnesium, beryllium and aluminium, boron and carbon. The double circles indicate pleiads of isotopes. Certain features of this table are contained in Loring's Wedge tables, Fig. 4. Fig. 1. C.R.N. 1920. Fig. 2 gives the form suggested by Prof. J. R. Partington (The Chemical News, 1920, CXXI., 304), who points out that his scheme makes the Soddy-Fajans relation apparent. The spiral method of representation serves to indicate the relationships of the elements quite as well as the ordinary tabular classification. It will be noticed that in this scheme atomic numbers are given, but obviously these can be inserted in any periodic classification in lieu of atomic weights. of the Another Spiral Classification. Elements was introduced by L. B. Tansley (The Chemical News, 1921, CXXII., 121), which is intended to bring out the evolutionary linkings of the elements, The "radials, and they have companions on each side. The long and "short periods of the ordinary table are dispensed with, and the elements of the eighth group fit in quite well. The rare-earth elements are also accounted for and space is left for undiscovered elements. More recently (this Journal, 1922, CXXV., 387), F. H. Loring has given a Wedge Periodic Table. A later form appeared in this author's The Chemical BA THE WEDGE PERIODIC TABLE OF THE ELEMENTS THE ATOMIC NUMBER OF THE INERT GASES A IS GIVEN Hel 3 THE ATOMIC NUMBERS OF ALL THE FOR EXAMPLE, SCANDIUM IS 3+18 21. 14 22 23 24 25 29/30 28 Tl Pb Bi Raf 27 26 d Os Ir Pt Au Hg bc 2/3/4/5 6 K Ca Sc Ti V Cr 45 6 7 Rb Sr Y Zr Nb Mo 13 Fe Co Ni Cu Zn Ga Ge As Se Br 16 17 15 12 13 ca 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Ta W Sa Eu Gd Tb Dy Ho Er Tm Yb LuCt 36 Fig. 4. THE RADIO-ELEMENTS NO ELEMENTS HERE, AND EXCEEDINGLY SMALL QUANTITIES OF ELEMENTS, REPORT OF THE DIVISION OF CHEMISTRY, UNION OF SOUTH AFRICA, FOR YEAR ENDED 30 JUNE, 1924. Chief of Division: CHAS. F. JURITZ, M.A., D.Sc., F.R.S.E., F.I.C. (now retired). WIDE RANGE OF ACTIVITIES. The present report is the first to deal with the activities of the entire Division, as now constituted, for the period of a full year. The extent of those activities, the institutions in connection with which they are carried out, and the relations of these institutions to each other, including the manner in which they either aid or supplement each other's work, as well as their individual relations to the general public, were all set forth in last year's report. Speaking broadly, the chemical work performed in the Pretoria and Grootfontein laboratories is of an investigational character, while that carried out in the Johannesburg laboratory is practically exclusively control or routine work. In the Cape Town institution, work of both kinds is undertaken. The number of routine samples examined in the Cape Town and Johannesburg laboratories was 9,658, and the tariff values of the work involved £19,868. NEW LABORATORY FOR ASSISTANCE OF THE PUBLIC. Free technical advice and the use of the finest laboratory of its kind in Europe have become available to the public by a scheme of centralisation of effort organised by the British Portland Cement Association. With the object of improving the advisory side of their work, this Association, which is a nontrading body, has arranged for the transfer of several existing laboratories to their premises in Westminster, and the concentration at one headquarters will add greatly to the usefulness of the work. The new organisation is intended to advise anyone on any subject connected with concrete or on cement in its application to concrete. Architects,builders engineers, corporations, etc., can there obtain expert. opinion on the material suitable for any particular work, and specimens of concrete or cement submitted will be tested free of charge on the most up-to-date apparatus. Private individuals also will be able to receive advice on any proposed development of their property, whether it be in the nature of a new carriage drive, garage. tennis court, "squash court, or even the rendering of a wall. General Notes. CHANCE FOR CHEMICAL ENGINEERS TO BRUSH UP. Chemical engineers who have been out of college for some years and who feel the need to brush up on their fundamentals of chemical engineering methods, will be given the desired opportunity this year at the Chemical Exposition which will be held September 28 to October 3, at the Grand Central Palace, New York. A special course in chemical engineering which will be given in conjunction with the Exposition, will be divided into two groups. Section I. for college students, and Section II. for advanced students, graduate students, and engineers of industry who are desirous of reviewing their work. Lectures will be given by leading authorities in the various fields and will cover fundamentals and advanced work in engineering. Prof. W. T. Read, of Yale University, will have charge of the complete courses. Lectures will be held in the Grand Central Palace and tours of the Exposition for demonstrations will be conducted after the lectures. Entries for the course should be filed with the management. Chemical Exposition, Room 1102, Grand Central Palace, New York. The course is without charge. |