Abstract
LONDON. Royal Society, June 25.—Sir William Crookes, president, in the chair.—Sir W. Crookes: The spectrum of elementary silicon. The author has tried in vain for years to get pieces of fused silicon in an approximate degree of purity. Lately the Carborundum Co. at Niagara Falls sent him three samples giving an analysis of 99.6, 99.86, and 99.98 per cent. of silicon, the impurities being titanium, iron, and aluminium. This material has been used in the present research. The paper gives a complete list of silicon lines from λ 2124.163 in the ultra-violet to λ 6371.032 in the extreme red, with some remarks referring to missing or doubtful lines.—Prof. S. P. Thompson; Note on Mr. Mallock's observations on intermittent vision. In his paper of December, 1913, on intermittent vision, Mr. Mallock discussed the phenomena observed when a rotating disc of twelve black sectors painted on a white ground is viewed while a slight mechanical shock is given to the body or head. He concluded that a mechanical acceleration imparted thus to the nerve structures on which vision depends produces a momentary periodic paralysis. The author, repeating Mr. Mallock's experiments, finds that effects of precisely the same kind appear when, on viewing the rotating sector disc in a mirror mounted elastically on a support, slight mechanical shocks are given to the mirror instead of to the observer. He therefore attributes the effects, both in Mr. Mallock's original experiments and in his own, to momentary minute displacements of the image on the retina, stimulating rods and cones which are relatively unfatigued and which therefore are momentarily of greater sensitiveness.—T. R. Merton: Attempts to produce rare gases by electric discharge. An investigation has been made of the apparent production of neon and helium by electric discharges in vacuum tubes. An apparatus has been designed in which protection from atmospheric contamination can be secured by a mercury seal throughout the experiment. It has been found that the presence of argon in the residual gases furnishes an exceedingly sensitive test for atmospheric contamination, and that a mercury seal can only be relied on if precautions are taken to ensure that the mercury and glass are scrupulously clean. The author has not been successful in reproducing the conditions necessary for the production of neon and helium.—A. C. G. Egerton: The analysis of gases after passage of electric discharges.—C. T. Heycock and F. H. Neville: Dilute solutions of aluminium in gold.—Prof. F. G. Donnan and G. M. Green: The variation of electrical potential across a semipermeable membrane.-J. H. Jeans: The potential of ellipsoidal bodies and the figures of equilibrium of rotating liquid masses. Sir G. Darwin was convinced that the pear-shaped series of figures of equilibrium discovered by Poincare was initially stable, while M. Liapounoff had with equal conviction announced that it was unstable. The present investigation was undertaken primarily in the hope of deciding between these two views. The main conclusion arrived at is somewhat disappointing. It is that, in spite of the labours of Poincare, Darwin, and Liapounoff, we have still no definite knowledge as to the stability or instability of the pear-shaped figure. All these investigators have worked at the question of the stability of the pear-shaped figure carried so far as the second order of small quantities. The present paper indicates that, so far as second-order terms, there is a doubly-infinite series of such figures which can, of course, be broken up into linear series in as many ways as we please. So far as can be seen. Sir G. Darwin has concerned himself with only one of these series, while M. Liapounoff has presumably dealt with a different series. It appears that the true linear series demanded by the general theory of Poincaré (Act. Math., vii., p. 259) only reveals itself when the computations are carried so far as the third order of small quantities, a conclusion which is confirmed by the result of a previous investigation on the figures of equilibrium of rotating cylinders (Phil. Trans., A. 200 (1902), p. 67).—Dr. C. Chree; The 27-day period in magnetic phenomena. The author has dealt in two previous papers in the Philosophical Transactions with data which seemed to confirm the reality of a period of about 27 days in magnetic phenomena, in the sense that it any particular day is more than ordinarily disturbed, or more than ordinarily quiet, the day which is 27 days later shows a decided bent in the same direction. In these investigations use was made almost entirely of magnetic “character” figures. As international “character” figures do not exist for years prior to 1906, and as “character” figures assigned at one station are open to certain objections, it appeared desirable to ascertain whether or not the 27-day period is clearly shown in the average year by the amplitude of the daily ranges of the magnetic elements. This is investigated in the present paper, use being made of the Kew declination horizontal force and vertical force ranges from 1890 to 1900, treated independently. The period is found to be clearly shown by the range of each element.—J. J. Nolan: Electrification of water by splashing and spraying. Water is broken into fine drops—(1) by allowing it to fall into a horizontal air stream of high velocity; (2) by spraying. The size of the drops and the charge per c.c. of water are measured. The conditions of the experiments enabled measurements to be made for drops of different sizes. It is found that the charge is positive and inversely proportional to the radius of the drops. This result follows if we assume that there is a constant charge produced per unit area of new water surface formed. The value of this constant is approximately 2.7×10-3 electrostatic units for distilled water, the splashing and spraying methods giving identical results.—W. G. Duffield; Effect of pressure upon arc spectra. No. 5.— A. Campbell and D. W. Dye: The measurement of alternating electric currents of high frequency. As the accurate measurement of currents larger than 1 ampere at high frequencies presents considerable difficulty, the authors have investigated the accuracy obtainable in the use of air-core current transformers (suggested by Mr. T. L. Eckersley). It is found that, with proper design, such transformers allow of the measurement of currents up to 50 amperes or higher, at frequencies from 50,000 up to 2,000,000 per second, with an accuracy of 1 or 2 parts in 1,000. Over the same range of frequency it is also found that iron-cored transformers can easily be designed so as to give very accurate results.—Sir D. Bruce, Maj. A. E. Hamerton, Capt. D. P. Watson, and Lady Bruce: (1) The trypanosome causing disease in man in Nyasa-land. The Liwonde strain. Part i.—Morphology. Part ii.—Susceptibility of animals. (2) The naturally infected dog strain. Part i.—Morphology. (3) Susceptibility of animals to the naturally infected dog strain. (4) Morphology of various strains of the trypanosome causing disease in man in Nyasaland. The human strain. vi.-x. (5) The trypanosome causing disease in man in Nyasaland. ii.—The wild game strain. iii.—The wild Glossina morsitans strain. Part ii.—Susceptibility of animals. (6) The naturally infected dog strain. Part iii.—Development in Glossina morsitans. (7) The naturally infected dog strain. Part iv.—Experiments on immunity.—Dr. F. Horton: The origin of the electron emission from glowing solids.—W. A. D. Rndge: Some sources of disturbance of the normal atmospheric potential gradient.—Prof. J. Joly: A theory of the nature of cancers and of their treatment by radio-therapy.— C. S. Mummery: Morphological studies of benzene derivatives. VI.—Parasulphonic derivatives of chloro-, bromo-, iodo-, and cyano-benzene.—F. H. Newman: Absorption of gases in the discharge tube.—Miss M. P. FitzGerald: Further observations on the changes in the breathing and the blood at various high altitudes.—W. E. Agar: Experiments on inheritance in parthenogenesis.—C. S. Myers: The influence of timbre and loudness on the localisation of sounds.—S. J. Kalandyk: (1) The conductivity of salt vapours. (2) The ionisation produced by gas reactions. The experiments described in (1) show:—1. The conductivity of the salt vapours is due to the processes occurring in the vapours themselves. 2. The vapours of carefully dried salts conduct the electric current. Therefore the conductivity cannot be ascribed to the chemical action of water vapour in the salt vapours. However, the presence of water vapour increases the current passing in salt vapours. 3. When cadmium iodide was very carefully dried it was possible to observe a current which was practically independent of time. 4. The connection between the current i and the temperature θ may be expressed with considerable accuracy by the formula i = ae - b/θ where a and b are constants. 5. The ionising potential calculated from the energy of dissociation is considerably less than for the ordinary gases. 7. The dissociation of vapours is not always accompanied by ionisation.—H. Richardson: The excitation of γ-rays by β-rays.—F. E. E. Lamplough and J. T. Scott: The growth of metallic eutectics.—W. E. Curtis: Wavelengths of hydrogen lines and determination of the series constant, (1) The wave-lengths in I.A. of the first six lines of the hydrogen series have been determined with an accuracy of about 0.001 A.U. (2) Balmer's formula has been found to be inexact. The results may be represented by a modified Rydberg formula containing only two constants, thus:—
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Societies and Academies . Nature 93, 521–525 (1914). https://doi.org/10.1038/093521b0
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DOI: https://doi.org/10.1038/093521b0