Abstract
LONDON. Royal Society, February 1.—O. W. Richardson: The magnitude of the gyromagnetic ratio. The gyro-magnetic ratio has the value m/e instead of 2m/e, the value calculated on the turning electron orbit theory of magnetism of the Langevin type; the discrepancy may be due to the rotation of the atomic nucleus. In iron it appears that the effective electron orbits possess altogether two quanta of angular momentum per atom and the nucleus a single quantum of angular momentum on this view.—Sir Richard Paget: The production of artificial vowel sounds. Plasticene resonators were used to imitate resonances heard by the writer in his own voice when breathing various English sounds. The first models, made in rough imitation of the oral cavity, gave two double resonances. The models were tuned by appropriate alterations of form until they gave recognisable breathed vowel sounds when blown through a small orifice at the back. An artificial larynx was made by means of a rubber strip laid edgewise across a flattened tube, and, when blown through this larynx, the models gave recognisable voiced vowels. The oral cavity behaves in every case as two Helmholtz resonators in series, and the remaining vowel sounds were reproduced by forming two separate resonators joined together in series, and made of such capacity and size of orifices as to allow for mutual reaction of resonators on their respective resonant pitch. Vowels may be produced by two resonators in series with a larynx between them, and a single tubular resonator may act as two resonators in series. Two resonators in parallel, blown by means of a single larynx with a bifurcated passage, produced vowel sounds indistinguishable from resonators in series.—F. Simeon: The carbon arc spectrum in the extreme ultra-violet. The arc-spectrum of carbon gives lines in the Lyman region at 1194, 94.5, 858, 687, 651, 640, 599, and 595, which have not been previously observed. They correspond with prominent lines in the “hot-spark” spectrum studied by Millikan. Groups of lines have been found at 1657, 1560, 1335, 1329, 1260, 1194, 1175, 1036, and 651, of which those at 1329, 1260, 1194, 1036, and 651 do not seem to have been observed by any other worker, and that at 1657 has not been completely resolved heretofore.—J. Joly: Pleochroic haloes of various geological ages.—H. A. Wilson: The motion of electrons in gases.—H. Hartridge: The coincidence method for the wave-length measurement of absorption bands. Measurements of the absorption bands of pigments by the ordinary spectroscope are inaccurate because of the breadth of the bands and the indefiniteness of their margins. The adjustment of two similar absorption bands into coincidence can be effected with-considerable accuracy. If then a spectroscope is designed in which two spectra are seen side by side on looking down the eyepiece, but reversed in direction with one another, the measurement of the mean wave-length of the absorption bands can be accurately carried out. The quantitative estimation of pigments depends on the movement of the bands which occurs when the concentration of one pigment changes. In measuring the percentage saturation of blood with carbon monoxide from the wave-length of the a-absorption band, the accuracy of measurement is approximately 0.7 Å.U. The probable error in setting two absorption bands into coincidence is little greater than that of setting two sharp black lines into coincidence, or of making one line bisect the area between two others.—A. Berry and Lorna M. Swain: On the steady motion of a cylinder through infinite viscous fluid. The so-called “inertia” terms are neglected and a solution is found which satisfies the boundary conditions on the cylinder and makes the velocity only logarithmically infinite in one direction at infinity. The relative velocity increases comparatively slowly with the distance from the cylinder, and the solution should give a fairly good approximation to the motion at small distances from the cylinder. First, the elliptic cylinder is treated as a limiting case of the ellipsoid. The solution, which in the case of the ellipsoid satisfies the boundary conditions and those at infinity, leads to a solution for the elliptic cylinder. The plane laminae, both along and perpendicular to the stream, are considered as limiting cases, and further, the motion due to the circular cylinder is deduced as a special case of the elliptic cylinder. Secondly, the solutions for the elliptic and circular cylinders are obtained directly from the equations of motion. Finally, stream-lines, curves showing vaiiation of velocity along stream-lines and curves of constant velocity are drawn for three limiting cases.—W. Jevons: The line spectrum of chlorine in the ultraviolet (Region λ 3354-2070 Å.). Observations of the spectrum of the chlorine discharge tube, which have not hitherto extended lower than λ 3276 Å. (Eder and Valenta), have been continued so fars λ 2070 Å. by means of 10-feet grating and quartz-prism spectro-graphs. Wave-lengths and wave-numbers of nearly 200 newly observed Cl lines are recorded, together with the effects of variations of capacity on the intensities of more than 100. The constant differences (Δv) 40·4, 67·1, 107·5, found by Paulson in pairs and triplets above λ 3276 Å. recur in a few pairs below that point. The significance of these separations in relation to the analysis of the spectrum, however, appears doubtful, since there is no apparent regularity in the intensities of the lines involved, and no triplets having these separations have been detected in the region under investigation.—M. H. Evans and H. J. George: Note on the adsorption of gases by solids and the thickness of the adsorbed layer. The amount of carbon dioxide adsorbed by unit surface of glass, at a pressure approximating to one-sixth of an atmosphere, suggests that the carbon dioxide is condensed on the surface of the glass in a liquid layer having a thickness equal to between five and six times the diameter of the molecule of the gas. By combining this result with the published figures of Mülfarth (Ann. d. Physik, 1900, vol. 3, p. 328) on the relative adsorption by glass of the gases acetylene, nitrous oxide, carbon dioxide, sulphur dioxide, and ammonia, it is found that these gases are adsorbed by the surface to such an extent that if they were present as liquid layers, the thickness of the layers would vary from (in the case of acetylene) three, to (in the case of ammonia) forty molecular diameters. A direct determination of the degree of adsorption of ammonia gives a value of the same order as that calculated from Mülfarth's data. The results are in disagreement with Langmuir's recent generalisation that the forces of attraction exerted by a surface do not extend to a distance greater than the diameter of one molecule.
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Societies and Academies. Nature 111, 205–208 (1923). https://doi.org/10.1038/111205a0
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DOI: https://doi.org/10.1038/111205a0