Societies and Academies

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    LONDON.

    Royal Society, June 27.-Sir J. J. Thomson, president, in the chair.-Prof. T. H. Havelock: Periodic irrotational waves of finite height. It is shown that an extension of Michell's analysis for the highest wave gives a method which includes waves of any permissible height.-Dr. G. N. Watson: The. diffraction of electric waves by the earth. Approximate formulas have been obtained by Poincare\ Macdonald, Nicholson, and others, which express the disturbance due to a Hertzian oscillator at a distant point of the earth's surface. This paper contains a transformation of the series for the magnetic force into a series which converges very rapidly except in the immediate neighbourhood of the oscillator.-Dr. A. D. Waller: Concerning emotive phenomena. Part ii. Periodic variations of conductance of the palm of the human hand. This paper gives an account of further observations of changes of electrical resistance associated with emotive phenomena. Their physiological lost time is between two and three seconds, and occurs principally in the skin (palm of hand). With higher and lower conductivity the effects are greater and smaller. The electrical conductivity (palm of hand) exhibits a diurnal periodicity concurrent with the waxing and waning of physiological activity during the twenty-four hours,-Prof. J. A. MacWilliam: The mechanism and control of fibrillation in the mammalian heart. An essential condition in fibrillation is an altered (fascicular) mode of conduction. This may characterise even single beats as " fibrillar." The production of a rapid, continuous series of contractions in typical fibrillation depends on a disturbance in the normal, relations of conduction time and refractory period, leading to the establishment of a mechanism of circulating excitations. Gradations are traced between fibrillar beats and rapid fibrillation. The chief protective and remedial agents described are urethane, adrenaline, strontium chloride, hirudine, and pilocar-pine. The action of the last may reproduce the different actions of the vagus in auricles and ventricles respectively, promoting fibrillation in the former and restraining it in the latter.-Dr. J. F. Gemmill: The development of the sea anemones, Actinoloba dianthus and Adamsia palliata. An account is given of the development of these anemones from fertilisation to the eight-mesenteried stage. In both species the eggs are relatively small, those of Actinoloba containing so little food-yolk that the free-swimming planula feeds by the action of cilia on two precociously formed mesenteries (the future sulco-later'als), and afterwards crawls mouth-downwards with stomodæum everted, presumably obtaining food from the substratum. This is the only known instance of a feeding Actinian planula, and, indeed, the only previous detailed account of anemone development is that of Appellof for LTrticina, which has large yolky eggs.-

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    Societies and Academies. Nature 101, 419–420 (1918). https://doi.org/10.1038/101419a0

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