Abstract
LONDON. Royal Society, Nov. 14.—V. Henri and O. R. Howell: The structure and activation of the molecule of phosgene. An analysis of the ultra-violet absorption spectrum of phosgene vapour. The spectrum, about 270 bands between 3050 A. and 2380 A., has been photographed at pressures from 0.1 mm. up to 680 mm. and analysed. The absorption region is therefore the same as for all substances containing the CO group, but whereas with aldehydes and ketones the absorption reaches a maximum at about 2800 A., with phosgene it increases continuously towards the ultra-violet. The spectrum is purely vibrational. The bands consist of doublets with a separation of 0.5- 1 A., and of singlets distributed at regular intervals in the spectrum. As an aid to elucidating the ultra-violet spectrum, the Raman spectrum of phosgene was also obtained.—T. M. Lowry and C. B. Allsopp: A photographic method of measuring refractive indices. A film of liquid is formed between the half-platinised plates of a quartz etalon, illuminated with multi-chromatic light from a metallic arc, and the interference bands formed in the film focused on the slit of a spectrograph. After calibrating the instrument with an air film, the refractive index of the liquid is deduced from the number of ripples between two fixed points on the slit of the spectrograph.—C. P. Snow and E. K. Rideal: Infra-red investigations of molecular structure (3 and 4). The vibration-rotation band (n″ = 1/2 n′ = 3/2) of CO has been resolved completely. The general character of vibration-rotation bands carried by 1S molecules is discussed, and the CO bands are shown to be consistent with the scheme. A theoretical discussion includes constants of potential functions and description of band lines—P. M. S. Blackett, P. S. H. Henry, and E. K. Rideal: A flow method for comparing the specific heats of gases. A slow stream of gas passes through an electrically heated iron tube, to which are attached constantan wires, in such a way as to measure temperature difference between two points symmetrically placed on tube. Temperature distribution along the tube alters slightly, and, under certain conditions, measured temperature change is a direct measure of specific heat of gas.—J. H. Brink-worth: On the temperature variation of the specific heats of hydrogen and nitrogen. Specific heats of nitrogen can be calculated to an accuracy of 1 in 500, at 60° - 1200° K., using Callendar's characteristic gas equation. With a modified Planck-Einstein formula for rotational specific heat, hydrogen values agree extremely well with experiment below 600° K.; at 1000° K. they are high, but there is excellent agreement at 1200° - 1600° K. Moments of inertia of molecules of hydrogen and nitrogen are deduced.—R. W. Lunt and M. A. Govinda Rau: The variation of the dielectric constants of some organic liquids with frequency in the range 1 to 103 kilocycles. There is no variation for benzene, ether, or chloroform, but a slight increase for methylated ether, ethyl alcohol, acetone, aniline, and nitrobenzene takes place in the range 102- 103 kc. In this range the conductivity of aniline diminishes rapidly as the frequency is increased, that of nitrobenzene diminishes slightly, whilst that of ethyl alcohol and of acetone does not vary.—J. A. Hall: The international temperature scale between 0° and 100° C. An extensive intercomparison between the platinum-resistance thermometer and a number of mercury in verre dur thermometers, standardised by the Bureau International des Poids et Mesures, shows that the change from the latter to the former as the standard of the National Physical Laboratory, will not alter the temperature scale used by that institution by more than 0.002° C. between 0° and 50° C. or 0.005° C. between 50° and 100° C. Differences between scale defined by platinum thermometer and thermodynamic scale probably do not exceed a few thousandths of a degree between 0° and 50° C., or 0.01° C. between 50° and 100° C.—D. M. Murray-Rust and Sir Harold Hartley: The dissociation of acids in methyl and ethyl alcohol. In methyl and ethyl alcohols, HCl, HClO4, HClO3, HEtSO4, HSO3C6H5 are strong electrolytes, while HNO3, HCNS, RIO3 are weak acids. From measurements with hydrogen chloride, the mobility of the hydrion is calculated to be 142 in methyl, and 59.5 in ethyl alcohol. Addition of small quantities of water to solutions of acids in alcohol causes large decrease of conductivity of the strong acids and correspondingly large increase in case of weak acids, and can be used as a qualitative test for the two classes.—K. S. Krishnan: The influence of molecular form and anisotropy on the refractivity and dielectric behaviour of liquids. The theory of the optical and electrical properties of liquids outlined by Raman and Krishnan is applied to the case of benzene for which the necessary data are available. The change in the Lorentz refraction ‘constant’ in passing from vapour to liquid, and the effect of temperature and pressure variations on the ‘constant’ are successfully evaluated numerically. The application of the theory to the dielectric behaviour of liquid benzene is equally successful.
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Societies and Academies. Nature 124, 825–827 (1929). https://doi.org/10.1038/124825a0
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DOI: https://doi.org/10.1038/124825a0