Abstract
LONDON. Royal Society, June 26.—Sir Ronald Ross, K.C.B., vice-president, in the chair.—F. S. Phillips: Phos phorescence of mercury vapour after removal of the exciting light.—Dr. G. J. Burch: Light sensations and the theory of forced vibrations.—P. W. Bnrbidge: The fluctuation in the ionisation due to γ rays.—J. G. Leathern: The force exerted on a magnetic particle by a varying electric field.—Dr. W. Watson: The luminosity curve of a colour-blind observer.—Prof. W. M. Hicks: A critical study of spectral series. Part iii.: The atomic weight term, and its import in the constitution of spectra.—L. C. Martin: A band spectrum attributed to carbon monosulphide. A complex band system occurring in the spectrum of the electric discharge through carbon disulphlde vapour in addition to the bands due to sulphur, is also found in the spectrum given by sulphur in the carbon arc. These bands only occur in the presence of both sulphur and carbon, and are probably due to carbon mono-sulphide.—Igerna B. J. Sollas and Prof. W. J. Sollas: The structure of the skull of Dicynodon as revealed by serial sections. The structure of the skull has been demonstrated in a remarkably complete manner by reconstructions built up from serial sections. A single example has afforded nearly all the information which has been slowly accumulated from numerous specimens during the past half-century and has added the following facts, which are either new or were in need of confirmation:—(i) The vomer is grooved on its dorsal surface; (2) the basis cranii is continued forwards between the orbits as a median vertical plate, which lies in the groove of the vomer, and is itself grooved on the dorsal surface to receive the ventral edge of the mesethmoid; (3) the form of the mesethmoid is such as to suggest that it is an early stage in the formation of a cribriform plate; (4) septo-maxillary bones are present, lying within the internal nares without appearing on the face. They are not connected by suture with neighbouring bones and might easily be lost in fossilisation; (5) the pre-parietal bone is present, situated entirely in front of the pineal foramen and forming its anterior border; (6) a transverse bone exists, clearly marked off from the neighbouring bones by sutures; (7) the root of the tusk, invested by a thin layer of the maxillary bone, lies in a large cavity, to the walls of which the maxillary, lachrymal, jugal, and palatine bones con tribute; (8) the sutures separating the pro-otic from neighbouring bones are clearly exhibited; (9) the labyrinth of the ear shows all the three canals with their ampullæ and a long vestibule; (10) the articular surface of the lower jaw is complex, there is a small inner portion which is concave—as in reptiles, and a large outer portion which is convex—as in mammals.—W. Cramer and R. A. Kranse: Carbohydrate-metabolism in its relation to the thyroid gland. The effect of thyroid feeding on the glycogen content of the liver and on the nitrogen distribution in the urine.—Dr. G. W. C. Kaye and D. Ewen: The sublimation of metals at low pressures.—Dr. R. T. Beatty: The energy of Röntgen rays.—Dr. C. Chree: Some phenomena of sun-spots and of terrestrial magnetism. Part ii. The paper is a continuation of one termed for brevity S.M., which appeared in the Phil Trans., A. 212, p. 75. It is mainly devoted to the question of the existence of a period of approximately twenty-seven days in terrestrial magnetic phenomena. Independent studies of magnetic storms during a very long period of years at Greenwich and Toronto led Mr. Harvey and Mr. Maunder a good many years ago to the conclusion that an interval of about twenty-seven and a quarter days could be recognised between the commencements of successive magnetic storms in a greater number of cases than could reasonably be ascribed to pure chance. S.M. showed that whether one took the daily range of horizontal force at Kew, or the magnetic character of the day, there undoubtedly existed for the epoch 1890 to 1900 a period of twenty-seven days or slightly more, in the sense that if an individual day were highly or moderately disturbed, days twenty-seven or twenty-eight days later were on the average more disturbed than usual. The result was not peculiar to the large disturbances usually termed “magnetic storms,” and appeared in all the years examined, whether quiet or disturbed. The present paper finds the same result to hold true of the years 1906 to 1911 when use is made of the magnetic “character” figures which have been published since 1906 at de Bilt, under international auspices. It is also found that the result is as true of quiet as of disturbed characteristics. The paper also investigates whether the phenomena presented by the twenty-seven-day period vary with the period of the year, and what the relationships are, if any, between magnetic “character” and Greenwich measures of sun-spot area and faculæ and Wolfer's sun-spot frequencies. The apparent sun-spot relationships are found to vary a good deal from year to year.—A. Fowler: New series of lines in the spark spectrum of magnesium. From experiments on the spectrum of the magnesium arc in vacuo, it has been found that there are seven lines which are associated with the well-known spark line 4481.35, their wave-lengths being 3104.91, 2661.00, 2449.68, 2329.68, 2253.94, 2202.75, and 2166.35. The eight lines, taken alternately, fall into two series having their common limit at 49776 on the frequency scale. The series are analogous to the two principal series of hydrogen lines, which have recently been investigated by the author.—A. Fowler and W. H. Reynolds: Additional triplets and other series lines in the spectrum of magnesium. The paper gives particulars of eight new triplets which have been photographed in the ultra violet spectrum of magnesium, and improved wave lengths for some of the lines previously recorded. The Rydberg series of single lines has also been extended, and four strong solar lines of previously unknown origin have been identified with lines of this series. Attention is also directed to a probable second subordinate series of single lines. Formulæ representing the various series are given.—W. E. Curtis: A new band spectrum associated with helium. The paper describes a new band spectrum observed under certain conditions in vacuum tubes containing helium and hydrogen. The experiments suggest that the bands are due to helium, but until hydrogen can be more completely eliminated their origin cannot be regarded as definitely settled.—Sir W. de W. Abney and. Dr. W. Watson: A case of abnormal trichromatic colour vision due to a shift in the spectrum of the green sensation curve.—Dr. E. F. Armstrong and Prof. H. E. Armstrong: Studies on the processes operative in solutions (XXX) and on enzyme action (XX). The nature of enzymes and of their action as hydrolytic agents.—Prof. H. E. Armstrong and H.W. Gosney: Studies of enzyme action. XXI. Lipase. III.—Prof J. S. Macdonald: Studies in the heat production associated with muscular work. Preliminary communication.—Prof. F. Keeble, Dr. E. F. Armstrong, and W. N. Jones: The formation of the Anthocyan pigments of plants. Part vi.—T. Graham Brown: The question of fractional activity (“All or None” phenomenon) in mammalian reflex phenomena.—J. H. Andrew and Dr. A. Holt: The thermal effects produced by heating and cooling palladium in hydrogen.—Hon. R. J. Strutt: A peculiar form of low potential discharge in the highest vacua.—A. Mallock: Note on copying machinery.—W. Wahl: The relation between the crystal-symmetry of the simpler organic com pounds and their molecular constitution. Part ii.—G. A. Shakespear; Experiments on the temperature coefficient of a Kew collimator magnet.—W. Jevons: Spectroscopic investigations in connection with the active modification of nitrogen. III.: Spectra developed by the tetrachlorides of silicon and titanium.—Lord Rayleigh: The passage of waves through fine slits in thin opaque screens.—Prof. W. H. Bragg: The reflection of X-rays by crystals. II. In a previous communication (April, 1913) it was shown that the wave-lengths of homogeneous pencils of X-rays could be expressed accurately in terms of the space relations of a crystal. The formula λ = 2d sin θ connected the wave-length λ with θ, the glancing angle at which the pencil was reflected in the crystal face, and d the distance between parallel reflecting planes. The angle θ could be determined with accuracy, but want of exact knowledge of crystal structure threw difficulties in the way of a complete evaluation of wave-length. W. L. Bragg, using two independent methods of research (those of the Laue diagram, and of reflection in the crystal face), has shown that in all probability the value of d is 2.81 × 10–8 cm. From this it follows that the wave-length of the “B peak” is 1.10 × –8. Characteristic radiations having wave lengths 1.25 × 10–8 and 1.66 × 10–8 are emitted by bulbs having antikathodes of tungsten and nickel respectively. So far, as it has been found possible to measure the absorption coefficients, they belong to rays which are characteristic of the antikathode metals, and the quantum energy-Planck's constant multiplied by frequency—agrees well with the energy of the kathode ray which, according to Whiddington, is required to excite the X-ray, or which the X-ray can excite.—W. L. Bragg: The structure of some crystals as indicated by their diffraction of X-rays. An analysis of tlie Laue diagram of sylvine (KCl) shows that the diffracting centres are arranged on a space-lattice of the simplest cubical form. The diagrams of potassium iodide and bromide show that the diffracting centres are arranged on a lattice the element of which is the face-centred cube. Sodium chloride is an intermediate case. From this and other features of the diagrams, it is concluded that in all these crystals the atoms of metal and halide are arranged in a simple cubic lattice, rows parallel to the axes containing alternate atoms of either kind. In svlvine the equal weights of the atoms render them equally efficient as centres; in KBr and KI the heavy halogen atoms alone act, and so the pattern is characteristic of the face-centred cube lattice. The diagrams of other crystals are discussed in reference to these conclusions. By means of the X-ray spectrometer, described in a previous paper, the dimensions of these lattices can be accurately compared; and the relative magnitudes of the different orders of spectra reflected from any face, and from different crystals, yield information which confirms the above conclusions. It also appears that the weight associated with each point of the lattice is proportional to the mole cular weight of the substance. These conclusions yield the necessary information for the accurate cal culation of the wave-length of the X-ray.—Leonard Hill, J. M. McQueen, and W. W. Ingram: The resonance of the tissues as a factor in the transmission of the pulse and in blood pressure.—G. F. Davidson: Experiments on the flow of viscous fluids through orifices.
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Societies and Academies . Nature 91, 495–497 (1913). https://doi.org/10.1038/091495a0
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DOI: https://doi.org/10.1038/091495a0