Abstract
Annalen der Physik und Chemie, No. 5.—From experiment, here described, on magnetisation of steel during the hardening process, Herr Holtz concludes that the method offers no advantages in practice. Magnets can, indeed, be thus made six times as strong as by the ordinary method, but this holds good only for extremely weak magnetising force; as you increase the force the difference rapidly decreases, and ere long becomes in favour of the ordinary method.—Herr Schellbach and Herr Boehn describe some instructive effects got on plates covered with carbon-dust placed under a discharger of a Leyden jar. Various devices were introduced for reflection, &c., of the sound-waves, whose mechanical action is indicated by the resultant figures on the plates.—Herr Wroblewski finds that a tenfold increase of the viscosity of water (by dissolving a crystalloid or colloid in it) produces only a five or six-fold diminution of the value of the constant for diffusion of carbonic acid in pure water.—The lowering of tone undergone by a sounded tuning-fork when immersed in liquids having been attributed by Herr Auerbach to the circumstance that kinetic energy is dispersed in incompressible liquids in another way than in gases (the changes of state in liquids being supposed to occur isothermally, in gases isentropically), Herr Kolacek offers another explanation based on mechanical principles.—In an inaugural dissertation Herr Freund writes on some galvanic properties of aqueous metal-salt solutions, his experiments having been made by Paalzow's method; and the results for sulphate of copper solution differing about 5 per cent, from those formerly obtained by Herr Beetz, he offers an explanation of this; which, however, Herr Beetz rejects, adhering to his own numbers.—Herr Ketteler contributes a paper on the theory of double refraction, and Herr Racomels-berg writes on some topics in mineralogical chemistry.
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Scientific Serials . Nature 20, 234 (1879). https://doi.org/10.1038/020234b0
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DOI: https://doi.org/10.1038/020234b0