Abstract
LONDON. Royal Society, Nov. 15.1—F. A. Jenkins and H. de Laszlo: Structure of the violet bands of silicon nitride. The analysis shows a marked isotope effect for Si28N, Si29N, and Si30N.—R. A. Fisher: The general sampling distribution of the multiple correlation coefficient.—F. W. Carter: On the stability of running locomotives. The inherent riding qualities of locomotives are discussed from the point of view of their natural tendencies, whether to seek the centre of the track or to deviate therefrom. The locomotive of one truck or axle group is generally unstable. In the locomotive of two trucks, these have regions of stability, limited by running speed and by the forces between main and auxiliary trucks.—A. C. Menzies: Ground terms in the spectrum of nickel II and proposed standard wave-length in the Schumann region. The method already described of obtaining spectrograms with exposures of the order of 1/100 second in the Schumann region (by fusing wires) is particularly well suited to the investigation of ground-terms, and has been applied to elucidate those of nickel II.—J. M. Whittaker: On the principle of least action in wave-mechanics. The connexion between Dirac's wave equations and the equations suggested by the author in a recent paper are discussed.—H. Dingle: The spectrum of doubly ionised fluorine (F III). Comparison of the spectrum with that of singly ionised oxygen shows close correspondence, with a few exceptions.—J. A. V. Butler: The equilibrium of heterogeneous systems, including electrolytes (Part 3). An equation is deduced for the variation of the adsorption of a substance dissolved in a more polar medium with the electric field at the inèerface.—G. R. Goldsbrough: The tides in oceans on a rotating globe (Part 2). The method of Part I of this paper is applied to two types of flat rotating sea; a semicircular basin, deepest in centre and shelving towards circumferential edge, and a flat semicircular basin of uniform depth.—T. Bradshaw and G. H. Livens: The formula for the optical rotatory dispersion of quartz.—H. T. Flint: The new metric of Einstein and the wave equation.—A. Robertson: The strength of tubular struts.—G. S. Adair: A theory of partial osmotic pressures and membrane equilibria, with special reference to the application of Dalton's law to haemoglobin solutions in the presence of salts. The osmotic pressures of haemoglobin solutions in equilibrium with solutions of diffusible salts have been measured and correlated with determinations of the membrane potentials, and the distribution of diffusible ions. Within certain ranges of hydrion, salt and protein concentrations, a modified form of Dalton's law of partial pressures is applicable for analysing the observed osmotic pressures in terms of the diffusible ion pressure difference, and the partial osmotic pressure of the protein, ions. The value 67,000 obtained for the molecular weight haemoglobin in physiological salt solutions agrees with that previously determined for haemoglobin in distilled water.—A. T. Waterman: The effect of electric fields on the emission of electrons from conductors. An examination of the Schottky effect from the point of view of the Sommerfeld electron theory of metals. Accurate experimental data on the Schottky effect should therefore distinguish between the Sommerfeld theory and the classical.—W. Mandell: (1) The change in elastic properties on replacing the potassium atom of Rochelle salt by the ammonium group. The two substances are isomorphous. Their densities differ considerably, whilst smaller changes take place in the optical rotation, the refractive indices,—and the size of the space-lattices and of the interfacial angles. The ammonium salt is less elastic than the potassium salt, the deformation magnitudes being fairly uniformly increased in all directions. Comparison of the elastic curves shows that the inter-atomic forces in both are very similar and that the potassium atom is a sort of ‘key’ atom in the molecule. (2) The determination of the piezo-electric moduli of ammonium seignette salt.—A. M. Tyndall, L. H. Starr, and C. F. Powell: The mobility of ions in air. Part 4. Investigations by two new methods. At long ages, the positive ions have mobilities distributed over a small range with a mean value of about 1.25, which is independent of the humidity of the air. There is no evidence of initial positive ions in very dry air or in pure nitrogen. If any are formed, they nearly all transform in less than 1/100 sec. The mobility of both the negative and positive ions in air containing alcohol vapour is independent of the age of the ions from 1/25 to 2/3 sec.—A. M. Tyndall, G. C. Grindley, and P. A. Sheppard: The mobility of ions in air. Part 5. The transformation of the positive ions of short ages. An air blast method was used. A small quantity of ozone produces a marked increase in the rate of transformation; this effect may explain the different results obtained by various observers using different methods. The rate of transformation is greatly retarded if, before entering the air blast, the ions are formed in an atmosphere containing the vapour of certain alcohols of the aliphatic series.—L. J. Freeman: The spectrum of doubly ionised nitrogen (N III).—W. R. Dean: Fluid motion in a curved channel. The motion of fluid forced under pressure round the space between concentric circular cylinders may become unstable for a symmetrical disturbance. In certain cases the disturbance may be that which actually ensues when steady motion breaks down. It cannot persist in a straight channel. This effect of curvature may explain why there is not in a curved pipe a sudden increase in loss of head in the neighbourhood of the critical velocity.—H. E. Watson and A. S. Menon: The electrical conductivity of thin oil films. Part 1.—W. Kapucinski and J. G. Eymers: Intensity measurements in the secondary spectrum of hydrogen.—E. Rudberg: Some remarks concerning the production and absorption of soft X-rays and secondary electrons. The number of photoelectrons produced for one quantum of radiation absorbed is of the order unity. This result, with efficiency measurements on soft X-ray production using the photoelectric method, shows that the yield of such radiation when metals are bombarded with electrons of a few hundred volts energy is extremely small. A very much larger portion of the energy of the bombarding electrons reappears in smaller units as energy of secondary electrons, a great part of which are probably initially free conduction electrons of the substance.—B. Swirles: The internal conversion of gamma-rays. Part 2.—R. S. Bartlett: The increase in thermionic currents from tungsten in strong electric fields. Experimental results for the increase of thermionic currents with applied electric field at constant temperature show only general agreement with theory. Surface impurities in the cathode exert a marked effect.—L. H. Thomas: On the rate at which particles take up random velocities from encounters according to the inverse square law.
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Societies and Academies. Nature 122, 865–867 (1928). https://doi.org/10.1038/122865a0
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DOI: https://doi.org/10.1038/122865a0