Abstract
LONDON. Royal Society, Feb. 21.—P. Kapitza: The change in electrical conductivity in strong electric fields (Parts 1 and 2). The change of resistance in a transverse field at temperatures of room, of solid carbon dioxide and ether, and of liquid nitrogen, has been studied in many metals. It follows the same law in all of them. The formula obtained gives a square law in weak fields and a linear law in stronger fields. Change of resistance follows a linear law with increasing field, but in weak fields it is masked by disturbances existing in the metal equivalent to an internal magnetic field. This additional resistance is independent of temperature, while the ideal resistance has a constant value for a given temperature for each metal, independent of its physical and chemical state. The additional resistance is identical with the residual resistance which is observed at very low temperatures. Supra-conductivity is a general phenomenon in all metals, but is masked by additional resistance, which disappears at very low temperature in certain metals.—R. R. Nimmo and N. Feather: An investigation of the ranges of the long-range a-particles from thorium C and radium C, using an expansion chamber. ‘Extrapolated’ ranges 9-90 and 11-70 cm. in standard air were obtained for the long-range a-particles from thorium C in the ratio of 1:5-1.541 particles have been observed belonging to these groups. In addition, 9 had ranges between 12.5 cm. and 17 cm., and 13 had longer ranges. The range of the most abundant group of long-range a-particles from radium Cwas measured as 9-16 cm.; it is likely that there are others with ranges 8-1 cm., 10-0 cm., and 11-0 cm. respectively. Nearly 500 long-range particles from radium C were recorded.—C. R. Burch: Some experiments on vacuum distillation. The method of evaporative distillation can be applied to the derivatives of petroleum. An elementary kind of fractionation is possible. Petroleum derivatives of exceedingly low vapour pressure can be prepared.—E. C. C. Baly and N. R. Hood: The photosynthesis of naturally occurring compounds (4).—B. W. Currie and R. Alty: Adsorption at a water surface (1).—W. G. Palmer: Some adsorption isothermals for a plane platinum surface.—B. Lambert and A. M. Clark: Studies in gas-solid equilibria.—G. C. Laurence: Relative velocities of the alpha-particles emitted by certain radioactive elements.—H. W. Thomson and C. N. Hinshelwood: The mechanism of the homogeneous combination of hydrogen and oxygen.—E. G. Dymond and E. E. Watson: Electron-scattering in helium.—E. T. Hanson: Diffraction and resonance.—S. Goldstein: (a) The forces on a solid body moving through viscous fluid. (6) The steady flow of viscous fluid past a fixed spherical obstacle at small Reynolds' numbers. Oseen's equations for the flow of a viscous fluid at small Reynolds' numbers past a fixed spherical obstacle are solved completely, and a table given of the resulting values of the drag coefficient.—J. Taylor: On the chemical interaction of ions, and the ‘cleanup’ of gases at glass surfaces under the influence of the electrical discharge.—H. M. Macdonald: The total reflection of electric waves at the interface between two media.—L. Hartshorn and D. A. Oliver: On the measurements of the dielectric constants of liquids, with a determination of the dielectric constant of benzene. An accuracy of 1 in 10,000 is obtained, using a capacity method. The method requires a comparatively large volume of liquid. For very pure liquids in small quantities, a comparison method is used. The dielectric constant of benzene is 2-2825 at 20° C., with a probable error of ± 2 parts in 10,000, mainly due to difficulties of obtaining a sample absolutely free from water.—J. W. Fisher: The wave equation in five dimensions.—E. Griffiths and J. H. Awbery: Measurements of flame temperatures.—K. Lonsdale: The structure of the benzene ring in C6(CH3)6. The benzene ring in this compound is similar in shape and size to the six-carbon ring in graphite, the nuclear carbons having a diameter of 1-42 A. Three of the valencies of aromatic carbon are co-planar, the ring itself and all the side chain carbon atoms lying in the (001) cleavage plane. The puckered or ‘diamond’ type of benzene ring, and Morse's model are inadmissible.
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Societies and Academies. Nature 123, 337–338 (1929). https://doi.org/10.1038/123337a0
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DOI: https://doi.org/10.1038/123337a0