Abstract
LONDON. Royal Society, March 26.—O. W. Richardson and T. Tanaka: Regularities in the secondary spectrum of hydrogen. It has been possible to arrange 123 additional lines provisionally in 22 series. Three of these form a PQR combination. The present indications are that the moments of inertia of the emitters are spread fairly well over a range extending from the high value deduced from the PQR combination found previously to a value somewhat below the lowest value which has been deduced from Fulcher's second band. This involves an extreme variation by a factor of almost six in the moments of inertia.-S. Chapman: The lunar diurnal magnetic variation at Greenwich and other observatories. The systematic changes of magnetic declination at Greenwich, during the course of the lunar day, have been determined from hourly records extending over 63 years. This and other magnetic elements have been similarly studied, using shorter series of data, for the observatories of Batavia, Zikawei, and Pavlovsk. The character and magnitude of the lunar daily changes depend on the following factors: the position of the sun relative to the moon, the position of the sun relative to the equator, the distance of the moon, the sunspot epoch, and the general state of magnetic activity upon the earth-the latter being connected with particular disturbed regions on the sun's surface. The lunar daily magnetic variation varies much less with sunspot epoch, and much more with the magnetic activity, than does the solar diurnal variation. It is concluded that the lunar influence on the earth's magnetic field, exerted through the agency of the lunar tide in the earth's atmosphere, is most efficient in the polar regions.- H. T. Flint: A general vector analysis with applications to electrodynamical theory. The vector analyses in use, as a rule, are concerned with quantities represented by straight lines, and the space to which they are applicable is Euclidean. An account is given of an analysis in which a vector is represented by The vector is of infinitesimal length and Sx"represents a component measured in any system of co-ordinates. In any kind of space, Euclidean or not, in which a point B has co-ordinates (Sx1, Sx*,..., Sxn) wfth respect to A we shall regard 5a' as denoting a definite quantity, whatever the system of co-ordinates. In this space we shall suppose the geodetics unique and shall regard the geodetic arc joining A and B as the geometric representatives of the vector Sa.'. So far as possible the notation will be similar to that of Gibbs' vector analysis. The notation may be applied to space of any dimensions, but four-dimensional space is taken as fundamental. In many cases it is possible to employ a notation that leaves the formulae of ordinary vector analysis almost unchanged, and formulae of the restricted principle can be carried over to the general principle by merely applying rules of generalised vectors.-Miss M. O. Saltmarsh: The spectra of doubly and trebly ionised phosphorus (P III and P IV). The series system in the spectrum of doubly ionised phosphorus is a doublet system in accordance with the spectroscopic displacement law. Three members of the triplet series of the spectrum of trebly ionised phosphorus have been identified. For three groups of elements, each having its own characteristic electron structure, the sharp terms are greater than the diffuse terms with the same Rydberg number for the neutral and singly ionised element, but for higher stages of ionisation the diffuse terms are greater than the sharp.-D. M. Wrinch and J. W. Nicholson: Laplace's equation and the inversion of surfaces of revolution.-T. R. Merton and J. G. Pilley: On experiments relating to the spectrum of nitrogen. When helium at about 30 mm. pressure containing a very small quantity of nitrogen is excited by feebly condensed discharges, the arc spectrum of nitrogen is developed, and under these conditions is completely isolated from the spark spectra. The arc spectrum of nitrogen is not developed in the presence of an excess of argon under the same conditions in which it appears in the presence of helium. Special precautions have to be taken to ensure the purity of the gases. When nitrogen is excited by electron impacts there appears to be a direct transition as the energy of the impacts is increased from the negative band spectrum to the spark spectrum, which would imply that the rupture of nitrogen molecules is generally into ions rather than neutral atoms.-T. H. Havelock: Studies in wave resistance; the effect of parallel middle body. The ship is altered by inserting varying lengths of parallel middle body between the same bow and stern. The main problem is the study of the equivalent wave-making length of the ship, and its variation with velocity and with the length of parallel middle body. -T. Tanaka: Wave-lengths of additional lines in the many-lined spectrum of hydrogen. Some 560 new lines in the secondary hydrogen spectrum have been measured. Incidentally it was necessary to make measurements of a considerable number of lines in the oxy-hydrogen band spectrum.-H. S. Taylor: A theory of the catalytic surface. A catalytic surface seems to be composite, of atoms in varying degrees of saturation in a crystal lattice. The saturation varies from that in a plane surface to those which are only held to the surface by a single constraint. It is by this constraint that these outermost atoms differ from gaseous atoms. Thus several molecular species, for example, hydrogen and an unsaturated molecule, may be attached to the same atom of catalyst.-E. F. Armstrong and T. P. Hilditch: A study of catalytic actions at solid surfaces. Pt. XII. Some observations relative to those particles of a catalyst which participate in chemical change. The rate of decline of activity of several nickel catalysts in the presence of varying concentrations of impurities characteristic of natural fatty oils has furnished evidence supporting Taylor's hypothesis (v. above). The active nickel atoms seem to be actually detached from their neighbouring metallic atoms during the moment in which catalytic change is effected. Pt. XIII. Some factors controlling selective hydrogenation with particular reference to certain terpene derivatives. Whilst adjacent (conjugated) ethylenic linkages are converted completely to a saturated system, two separate ethylenic linkages are hydrogenated consecutively, one double bond disappearing completely before the other is attacked: acetylenic linkages are transformed to the saturated compounds with little or no production of the corresponding ethylenic compound. Similarly, the hydrogenation of esters or glycerides of polyethyl-enic higher fatty acids (but not the free acids themselves) is markedly selective, and the same applies to diethylenic derivatives of the terpene series. Selective hydrogenation, observed by ourselves and by Vavon, in compounds such as carvone, limonene, citral, geraniol, and linalool, is determined mainly by (i) degree of substitution of ethylenic carbon atoms, and (ii) proximity to one or other double bond of a carbonylic or hydroxylic group. It is also deduced from these results that citral, geraniol, and linalool all contain the grouping (CH3)2C =CH-. Selective hydrogenation is of considerable importance in relation to the general theory of catalysis at a solid surface.
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Societies and Academies. Nature 115, 517–520 (1925). https://doi.org/10.1038/115517a0
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DOI: https://doi.org/10.1038/115517a0