LONDON. Royal Society, Jan. 17.—A. S. Eddington: The charge of an electron (see p. 138 of this issue).—R. H. Fowler: The thermionic emission constant A. Nordheim's theory of the emission coefficient of elec trons from metals is used to explain the remarkable relation between the constants A and B of the therm ionic emission formula,first recorded by O. W. Richard son and recently reformulated by Du Bridge. This theory regards the emission as due to the passage of electrons through simple surface potential steps and double layers, to be calculated according to the wave mechanics.—J. A. Gaunt: The triplets of helium.—G. Temple: The tensorial form of Dirac's wave equa tions. Darwin's transformation of Dirao's wave func tions is incompatible with the theory of relativity. Dirac's wave equations are cast into tensorial form, from which are deduced the Lagrangian function, the charge and current tensor, the magnetisation and polarisation tensor, some associated quadratic invari ants.—H. M. Macdonald: The reflection and trans mission of electric waves at the interface between two transparent media.—D. K. Bhattacharyya: On the analysis of the first spark spectrum of sulphur. The data of Eder and Valenta between A3028 to A5819, and certain observations of Keeler and Lockyer regarding the occurrence of S+-lines in stellar spectra, are used. The spectrum in the red region up to 7715 was also photographed, using neocyanine plates and a Wood type of discharge tube. A band-system in the red, seemingly analogous to atmospheric bands of oxygen, has been found.—J. S. Foster: Effect of combined electric and magnetic fields on the helium spectrum. Parallel electric and magnetic fields are applied to a helium source, and the light analysed by a prism spectrograph of high dispersion. The effects in the parhelium and orthohelium spectra are clearly addi tive in the sharp and principal series, and for the com ponents of the diffuse lines which are resolved. The magnetic separation is independent of the magnitude of the Stark-effect.—R. W. B. Pearse: The ultra violet spectrum of magnesium hydride (1). In addition to the well-known visible (a) band system, two others, a /3-system, represented by a strong band at A2430 and a 7-system covering the range A5500-A2300, have been found in the ultra-violet.—J. S. Foster and W. Rowles: Patterns and Paschen-Back ana logue in the Stark-effect for neon. In an attempt to determine Stark-patterns in neon, 150 lines were examined by the Lo Surdo method in fields as high as 140 kv./cm. An appreciable number of the diffuse and combination lines have a new pattern.—J. K. L. MacDonald: Stark-effect in a violet region of the secondary spectrum of helium. Effects for twenty lines are observed in the region 3980-4080 A. The Lo Surdo type of discharge tube is used; displacements are measured at a field strength of 95,000 volts per cm. Certain apparently complex effects are resolved into simple displacements of closely lying lines.—J. S. Foster and M. L. Chalk: Relative intensities of Stark components in hydrogen. A report of a quantitative investigation of the relative intensities of the stronger Stark components in the first four members of the Balmer series. In all cases the results agree within experimental error with the new calculations by Schro-dinger.—O. R. Baldwin: The relativity theory of divergent waves. The solution given be Einstein for the general problem of the propagation of gravitational waves was used by Eddington to find the solution for waves created by a spinning rod. An attempt is now made to discover all the non-spurious waves of the same general character at infinity as Eddington's.—G. W. C. Kaye and W. F. Higgins: The thermal con ductivity of solid and liquid sulphur. The tempera ture range was 20° C.—2100 C. A ‘plate’ method with a small temperature drop across the specimen was used.—S. Barrett and C. P. Stein: On bromine chloride. From spectrophotometric observations on the colour changes on mixing carbon tetrachloride solutions of bromine and chlorine, the two halogens give an equili brium concentration of bromine monochloride. The formation of a chemical compound between them is further indicated by the appearance of a new ultra violet absorption band with its maximum at 3700 A., peculiar to the mixtures, and also by the fact that the colour change in carbon tetrachloride solution takes an appreciable time.—C. W. Gibby, C. C. Tanner, and I. Masson: The pressure of gaseous mixtures (2). The compressibilities, up to 125 atm., of helium, hydrogen, and ten mixtures of the two, at 25°, and of each pure gas and an equimolecular mixture at seven tempera tures from 25° to 175° have been measured.—J. Chariton and C. A. Lea: Some experiments concerning the counting of scintillations produced by alpha-particles (Parts 1-3). (1) Determination of the smallest amount of luminous energy perceptible by the eye. (2) De termination of the efficiency of the transformation of the kinetic energy of the a-particle into radiant and luminous energy for various zinc sulphides. (3) In vestigation of the way in which the number of scintilla tions observed is affected by the numerical aperture of the optical system used.
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Annalen der Physik (1930)