TY - JOUR
AB - LONDON. Royal Society, December 8, 1921.—Sir C. S. Sherrington, president, in the chair.—Lord Rayleigh: A study of the glow of phosphorus: Periodic luminosity and action of inhibiting substances. The intermittent or periodic luminosity observed when the last traces of oxygen are being removed from air by means of phosphorus, or when air is allowed slowly to leak into an exhausted vessel containing phosphorus, requires the presence of water-vapour. Moderate drying (e.g. by sulphuric acid) makes the glow perfectly steady. Water-vapour has therefore the power of inhibiting the combination of phosphorus-vapour and oxygen within certain limits. When the composition of the mixture becomes favourable beyond those limits, a wave of combustion is propagated. Other substances are known to inhibit the glow of phosphorus, and exhibit the above phenomena in a more striking form than water. Camphor, ammonia, and pear-oil are among the most effective. The propagation of these waves of combustion cannot be attributed to the rise of temperature of one layer igniting the next layer, for the rise of temperature is too small. An alternative theory of the propagation is proposed, which assumes that it depends on the provision of nuclei, as in the propagation of crystallisation through a super-cooled liquid. On this basis a theory of the action of the inhibitors or “negative catalysts” is developed.—Lord Rayleigh: The aurora line in the spectrum of the night sky. The spectrum of the night sky at Terling (near London) has been photographed systematically. The aurora line at wave-length 5578 Å.U. is recorded on about two nights out of three. Its intensity on ordinary nights is not obviously related either to the amount of magnetic disturbance or to the transit of spots over the sun's central meridian. The intensity in the neighbourhood of Newcastle is notably less than near London, thus the effect appears to increase towards the south. It appears, therefore, 10 be due to some different cause from the Polar aurora. The aurora line does not coincide with krypton, and experiments to determine its origin gave negative results.—E. F. Armstrong and T. P. Hilditch: A study of catalytic actions at solid surfaces. VII.: The influence of pressure on the rate of hydrogenation of liquids in presence of nickel. The comparative rates of absorption of hydrogen at different pressures by a variety of unsaturated compounds in presence of nickel have been studied; the relation between the hydrogen pressure and the rate of hydrogenation is dependent on the type of organic compound examined. Simple ethylenic compounds are hydrogenated at rates almost proportional to the absolute pressure of the hydrogen. At very low concentrations of catalyst the increase in rate of hydrogenation becomes less than proportional to the increase in pressure. If the unsaturated compound contains another group which has affinity towards nickel, but is not open to hydrogenation, increase in hydrogen pressure causes an increase in the rate of hydrogen absorption. These results are in harmony with the authors' theory that catalytic hydrogenation is primarily conditioned by an association of the ethylenic linkage with the catalvst, the latter being also associated with hvdrogen.—W. D. Womersley: The energy in air, steam, and carbon dioxide from 100° C. to 2000° C. Hydrogen and carbon monoxide mixed with either air or oxygen were exploded in a Hopkinson recording calorimeter for explosions. Curves showing the energy in the various gases and the mean volumetric heats from 100° C. to 2000° C. are given. The values are, where comparable, about 7½ per cent, higher than those of Holborn and Henning. The difficulty in estimating the heat liberated in a closed-vessel explosion is due probably to a spontaneous time reaction between the combustible gas and oxygen when the two are mixed, in which about 10 per cent, of the gas is consumed. The combustion of carbon monoxide is considerably slower than that of hydrogen. This makes the estimation of the heat liberated in the carbon monoxide experiments very uncertain.—J. W. Gifford: Atmospheric pressure and refractive indices, with a corresponding table of indices of optical glass. The modulus of rigidity for glass precludes its being sensibly affected by pressure, and therefore any pressure effect must be due to air alone. Two measurements of refractive index of the same wave-length, at different temperatures, are made, and by means of a new formula the refraction temperature-coefficient at standard pressure for 1° C. is determined. Using this as a final correction, indices for other wave-lengths at standard pressure and observed temperature may be brought to standard pressure and temperature (15° C.).—H. P. Waran: A new form of interferometer. A thin layer of transparent liquid floating over mercury is employed as a parallel plate interferometer—a substitute for Lummer and Ghercke's glass plate. Viscous castor-oil was successfully used, but its poor transparency stood in the way of securing high resolving power. The disturbing influence of the tremors of the ground was overcome by mounting the trough on a float suspended from the ceiling in a tank of water carried on a massive brick pillar with deep-laid foundations.—H. Harle: The viscosities of the hydrogen halides. An experimental determination of the coefficients of viscosity of the gaseous hydrogen halides was undertaken with the view of affording a check upon the theoretical investigation by A. O. Rankine on the diameters of unsymmetrical molecules. The method of continuous transpiration through a capillary tube was employed, using the known data for air. The gases were liquefied, and, by controlling the evaporation, established their own steady pressure while transpiring through the tube. The volumes of gas passing in a given time were found by absorbing in water and titrating with standard alkali solutions. Values of η were obtained at two temperatures, round about 15° C. and 100° C., and from them Sutherland's constant of temperature variation is calculated for each of the gases.
TI - Societies and Academies
JF - Nature
DO - 10.1038/109093b0
DA - 1922-01-19
UR - https://www.deepdyve.com/lp/springer-journals/societies-and-academies-oRVogVDfyC
SP - 93
EP - 95
VL - 109
IS - 2725
DP - DeepDyve
ER -