Abstract
LONDON.
Royal Society, June 28.Sir J. J. Thomson, president, in the chair.Sir Robert Ilacifield, Ch. Ch©neveau, and Ch. G©neau: A contribution to the study of the magnetic properties of manganese and of some special man- ganese steels. (i) The research has had for its object the investigation of the mass-susceptibility of man- ganese metal, and of certain of its alloys with iron and other metals. The work was carried out on a Curie- Ch©neveau magnetic balance. (2) Manganese itselt, when free from occluded gases, is para-magnetic, its value of being + 11.0 X IO_6 ±2 per cent. This corresponds on Weisss theory to a number of magnetons equal to 6. The removal of occluded gases is essential, as the ferro-magnetic properties of certain specimens of manganese are shown to be due to the presence of hydrogen. (3) The manganese alloys investigated, with one exception, are all para-magnetic, x varying from 17oX IO_6 to 2590 X IO_6. The exception men- tioned is a silico-manganese steel containing 6 per cent. of silicon, which is distinctly ferro-magnetic. () An endeavour is also made to correlate the values of the mass-susceptibility with the composition of the alloys. In tlis connection it has been shown that the quantity of manganese within the limits investigated has very little influence upon the susceptibility, whilst increase of carbn tends to decrease it In general it is con- cluded that in these special steels the susceptibility decreases as the carbon-manganese ratio increases. (5) The carbon-manganese ratio being constant, addition of chromium, nickel, or tungsten raises the susceptibility. (6) The addition of copper to a manganese- nickel steel also raises the susceptibilitythis notwithstanding the diamagnetism of copper.W. R. Bousfield: Note on the specific heat of water. Reply- ing to criticisms by Callendar (Bakerian Lecture, Phil. Trans., A, 212, p. I, 1912) on the methods for investigating the specific heat of water described in a former paper (W. R. Bousfield and W. Eric BousfIeld, Phil. Trans., A, 211, p. 199, 1911), it is pointed out that the observations of Callendar do not substantially affect the question as to which figures are more correct in the lower range of temperature from o to 40 or o C. Callendar and Barnes differ from other observers in placing the minimum value for the specific heat of water in the neighbourhood of 4O C., whilst other observers put it at about 25 C.W. R. Bousfield and C. Elspeth Bousfield: The specific heat of aqueous solutions with special reference to sodium and potassium chlorides. The specific heats of solutions of NaCI and KC1 ranging from saturated solutions to quarter- normal solutions at mean temperatures of 7, 20, and 330 C. have been determined by the method and apparatus used for the determination of the specific heat of water and described in a former paper (Phil. Trans., A, 2ii,p. 199, 1911). The corresponding densities have also been determined. The relation of the specific heat of the solution to the specificcontraction of the water is studied, and it is shown that the specific heat of a series of solutions of different concentrations may be reckoned on the hypothesis that the specific heat of the solute is constant, whilst the mean specific heat lowering of the water is proportional to the specific contraction of the water. The temperature variations of the specific heats of the solutions are also compared with the temperature variations of the specific heat of water. The minimum value on the temperature- specific heat curve, which occurs at about 25 C. in the case of water, disappears altogether in solutions of half-normal to normj strength. This curve for the most concentrated solutions becomes a straight line. Sir George Greenhill: The Rankine trochoidal wave. The Rankine trochoidal wave (Phil. Trans., 1863), either as rollers or as a starting wave, can be divided up by vertical planes perpendicular to the wave crest into compartments, and the compartments sheared along each other. The investigation is made of the extra field of force in addition to gravity when the shear is made continuous and the planes removed in order that the continuity of pressure should be preserved in the interior of the water, and for the new wave motion to persist. ANn when the planes stand over to the vertical and the circular orbits in the roller are in parallel planes. A geometrical investigation is added of the molecular rotation in the interior of the Rankine waveDr. P. E. Shaw: The tribo-electric series. (I) The tribo-electric series, in which solid materials are arranged in order according to the charge they acquire when rubbed together, is trustworthy with due precautions. (2) Most solids are found to alter their place in the series if heated above a certain temperature hich is specific for each material. This temperature is called the critical temperature. The surface in its new condition is termed abnormal. () The series may be divided into an upper Group A and a lower Group B. It is found that these groups have tendencies contrary to one another as the surfaces of the materials are rendered (a) matte, or (b) abnormal, or (c) pressed, or (d) flexed. If under any of these agencies Group A becomes more + forming, Group B becomes more forming, and vice versa. (4) Anomalous effects are observed when liquid mercury is used as one of the materials, its behaviour being quite unlike that of solid surfaces. (5) As to theory, it is suggested that the pi evalent idea that the electric double-layer existing at the surface of solids has the layer outermost in all cases is incorrect. Normally the materials in Group A would have outermost, those in Group B having + outermost. Orientation of surface atoms would give rise to changes in the disposition of the two electric layers and so account for observed effects. (6) Tribo-electricity undoubtedly affords a means, of extraordihary delicacy, of discriminating between materials apparently alike. Two instances are seen in the group of furs andthe group of woods.J. J. Nolan: The nature of the ions produced by the spraying of water. Part i. gives an account of the determination of the mobilities of the very mobile ions produced by the spraying of water. Groups of ions are found, positive and negative, some of very high mobility. In part ii. the less mobile ions described in a previous paper are discussed. Treating the ions as minute spheres of water, it is shown that their sizes as deduced from an empirical modification of Stokess law would agree with the sizes calculated from the ordinary theoretical mobility formulai. Certain evidence, however, tends to show that the larger of these ions are not simple spheres of water, but that they consist of loose group- ings of various numbers of some smaller water- globules. In part iii. it is shown that the very mobile ions can be accounted for by supposing that they consist of aggregates of various numbers of water- molecules, the numbers of molecules in the various ions being related to one another in a regular way. Some of these ions have the same mobility as ions produced in air by X-rays, etc. It is suggested that the ordinary gaseous ion consists of a group of water-. molecules, the size of the group depending on the degree of moisture of the gas.Prof. J. C. McLennan: The absorption spectra and the ionisation potentials of calcium, strontium, and barium.J. Small: Geotropism and the Weber-Fechner law.Prof. W. B. Bottomley: The isolation from peat of certain nucleic acid derivatives.
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Societies and Academies . Nature 99, 419–420 (1917). https://doi.org/10.1038/099419a0
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DOI: https://doi.org/10.1038/099419a0