Abstract
LONDON. Faraday Society, November 16.—E. D. Campbell: A study of the correlation of the permanent magnetism and specific resistance of some pure iron-carbon alloys.—J. A. V. Butler: Co-ordination and co-valency. The formation of co-ordinated complexes cannot be due in general to the tendency of the central atom to attain the configuration of the next higher inert gas. The electrons contributed by coordinated groups form a distinct group round the central ion. A distinction is drawn between (a) Covalency: the mutual sharing of electrons by two atoms so as to complete already existent groups, therefore involving negative valences, and (b) Co-ordination: the formation of a new group of electrons outside the last group represented in the ion. It is proposed to use the specific term co-ordination valency for the number of co-ordinated groups. It is assumed that the co-ordination electrons enter the main “quantum group” next to that represented in the central ion.— J. R. Partington and N. L. Anfilogoff: An improved form of electric vacuum furnace. A vacuum furnace of the Ruff type was used for studying reactions at high temperatures. The reacting substances, if solids, are contained in a graphite crucible turned from the same material as the hot tube and maintainable either in a high vacuum or in an atmosphere of an inert or reacting gas. The issuing gas is capable of analysis.—]. R. H. Coutts and E. M. Crowther: A source of error in the mechanical analysis of sediments by continuous weighing. The low density of suspension immediately below the balance pan after the sedimentation has proceeded for a few minutes inevitably sets up a flow of liquid which interferes with the free vertical fall of the particles. With the large narrow-rimmed pans hitherto used, the observed yields are appreciably below the theoretical values. With the pan close to the base there is a very rapid change of yield with very small changes in the position of the pan.—Donovan Werner: A simple method of obtaining the size distribution of particles in soils and precipitates. The method has been developed in researches on the reaction mechanism during the formation of precipitates. It has been necessary to know the total surface of a precipitate as a function of time while the precipitate is forming. At first the particles can be measured by an ocular micrometer, but just as the particles become larger and more irregular in size during the precipitating process, at the same time forming aggregates, it becomes correspondingly difficult to get values sufficiently exact. The measuring of the velocity of the sedimentation gives an “accumulation curve,” and from this curve the size distribution can be calculated according to the mathematical theory developed by Oden.—F. G. Tryhorn and W. F. Wyatt: Adsorption by coco - nut charcoal from alcohol - benzene and acetone-benzene mixtures. Adsorption isotherms for each component of such mixtures have been determined at 20°. By an analogous method, measurements have been made of the composition of the vapours in equilibrium with mixtures of the above liquids at 20°. A comparison of the results of adsorption by charcoal from the liquid and the vapour phases supports the conclusion that an adsorbed film in equilibrium with a saturated vapour must be also in equilibrium with the liquid in contact with that vapour. Alcohol is selectively adsorbed from all mixtures of alcohol and benzene. From acetone-benzene mixtures, acetone is selectively adsorbed from mixtures containing up to 72 molar percentage of acetone in the vapour phase. Above that value benzene is selectively adsorbed to a slight extent.— F. L. Usher: The nature of the interfacial layer between an aqueous and a non - aqueous phase. Experiments were undertaken to obtain information on the question whether the ions bearing a charge of opposite sign to that of the non-aqueous phase are movable only as a complete layer, or whether some or all of them are independent; and secondly, on the extent to which the observed behaviour of aqueous suspensions is in agreement with the consequences deduced from the answer to the former question. They deal (i) with the determination of the total charge on the particles of a suspension by neutralising it with a measured quantity of ions bearing a charge of opposite sign, and (2) with the effect of electrolytes in modifying the surface charge.
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Societies and Academies. Nature 116, 921–924 (1925). https://doi.org/10.1038/116921b0
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DOI: https://doi.org/10.1038/116921b0