3°4 



NA JURE 



{Jan. 29, 1885 



of the gas. — C. Decharme, imitation of the phenomena of electri- 

 city and magnetism by means of liquid and gaseous currents. 

 Summarises number of experimental researches. — A. Kundt, 

 electromagnetic rotation of plane of polarisation of light trans- 

 mitted through films of iron, cobalt, and nickel ; an abstract 

 from the Berlin Berichte. — E. Bazzi, on the heat developed by a 

 current during the variable period. Experiments show Joule's 

 law still to hold good, assuming Helmholtz's equations true. It 

 has been remarked by Blaserna that this is not incompatible 

 with the existence of oscillations in the extra-current, for 

 Helmholtz's expression, though only a first approximation which 

 omits the terms that would express these oscillations, is probably 

 not far from the mean result. — The remainder of this number 

 consists of abstracts of papers by Amagat, Bailie, H. Pecquerel 

 (on infused rays), Cormi, Witz, and by Berthelot and Ogier 

 from the Annate de Chimie el de Phys'que. 



December, 1884. — E. Villari, new researches on the elec- 

 tric figures of condensers. The ramifications observed in the 

 dust-figures are believed to be due to partial internal dis- 

 charges. — E. Villari, microscopic researches on the traces 

 of electric sparks engraved on glass, and on the diameter 

 of these sparks. Tinted zones are observable where these 

 sparks have passed over the surface of the glass. These 

 traces vary with the glass, not with the nature of the electrodes ; 

 they are not removed by acids, and are probably due to heat. 

 The cross section of the spark is, for a constant potential, pro- 

 portional to the charge which produces it. — E. Villari, on the 

 total heat developed by one or more sparks generated by the 

 discharge of a condenser. — E. Villari, singular mechanical effect 

 of the electric discharge. Glass plates, even strong thick ones, 

 are easily broken by the spark of a Leyden battery, provided one 

 face be silvered. — A. Righi, on a recent interpretation of Hall's 

 phenomenon. Bidwell's theory of Hall's phenomenon appears to 

 fail in the case of bismuth, in which Hall's phenomenon exists 

 most markedly. It is also to be remarked that the variation of 

 the electric resistance of bismuth, when subjected to the mag- 

 netic field, is greater than that of any other metal. — R. Weber, 

 the electric siren. This instrument produces tones in a receiving 

 telephone by causing rheotomes having different numbers of 

 peripheral contacts rotated at a uniform speed to interrupt the 

 circuit of a battery. The author draws a number of conclusions 

 relatively to the partial and resultant tones, which are hardly 

 justified when one considers the non-sinusoidal character of the 

 variations of the current. — F. Melde, acoustical experiments, 

 abstracted from Wied. Ann. — P. de Heen, determination of the 

 general law governing the dilatation of any chemically definite 

 liquid. The author assumes that the molecules attract one 

 another in the inverse seventh power of the distance. Whatever 

 may be thought of the hypothesis, there is an interesting coin- 

 cidence running through his figures. — The remainder of the 

 number is filled with abstracts of papers from the Nuovo Cimento, 

 the most important of them being by E. Wiedemann, on the 

 density of the luminiferous ether, and by Profs. Bellati and 

 Romanese, on some remarkable thermic properties of the iodides 

 of silver and copper. 



Rendiconti del Reale hliluto Lomhardo, December II, 1884. 

 — Report on the results of the International Medical Congre s 

 held at Copenhagen during the month of August, by Prof. G. 

 Sangalli.— On the influence of high temperatures on the deve- 

 lopment of microbes, by Prof. L. Maggi. — A study of the earth- 

 quake which occurred at Ischia on July 28, 1883, by Prof. 

 Giuseppe Mercalli. — On the secular variation in the elements of 

 terrestrial magnetism at Como, by C. Chistoni. — Descriptive 

 catalogue of sixty-three hitherto unpublished Pontifical coins and 

 medals in the Royal Numismatic Cabinet at Milan, by E. B. 

 Biondelli. — The paintings of the Italian masters in the public 

 museums of Europe, in connection with Senator Morelli's recent 

 work, by Prof. G. Mongeri. — Critical notes on the fourth book 

 of the pseudo-Theophilus, by Prof. C. Ferrini. — Meteorological 

 observations made at the Brera Observatory, Milan, during the 

 months of November and December 1884. 



Journal of the Russian Chemical and Physical Society, vol. 

 xvi. fasc. 7. — On the heat of combustion of organic matters, by 

 W. Longuinine ; being a description of the methods resorted to 

 by the author in his series of determinations preliminary to the 

 subsequent publication of the re-ults obtained. The paper is 

 accompanied by several plates. — Analysis of a saltpetre earth 

 from Turkestan, by N. I.ubavin. It is taken from the ruins of 

 Kunya-Urgench, the climatic conditions being altogether very 



favourable for its formation, and its abundance explains the 

 cheapness of gunpowder at Khiva. It contains 6 per cent, of 

 azotic anhydride. The remarks of the author as to the connec- 

 tion between the formation of saltpetre and the inundations of 

 the Amu are worthy of notice. — Review of the Russian chemical 

 literature for the year 1883 and first quarter of 1884. — We notice 

 the appearance of a fifth edition of the excellent manual of 

 analytic chemistry by M. Menshutkin, as also of his lectures 

 on organic chemistry (lithographed), which are now in print ; 

 a third edition of P. Alexeyeff's organic chemistry, and a 

 second edition of the principles of chemistry, by A. Poty- 

 litsin, not to speak of several translations. As to separate 

 monographs, besides thoe already mentioned by Nature, the 

 following are worthy of notice: — The organic compounds in 

 their relations to the haloid salts of aluminium, by G. 

 Gustavson — a work which has obtained the premium of the 

 Chemical Society ; on the relations between the compositions 

 and refractory power of organic compounds, published at 

 Kazan, which has raised a serious and useful discussion 

 between Russian chemists ; and an inquiry into the atoms 

 and the measurement of their size, by O. Troyanovski 

 (Warsaw). — On the electrical discharge in gases, by M. 

 Goldhammer ; being a series of experiments for determining 

 the temperature in Geissler tubes. When rarefied air is 

 taken for the experiment, its heating does not depend on its 

 elasticity so long as this last remains within, the limits of 8 "4 to 

 38 millimetres ; but it decreases with the decrease of the electrical 

 current. The distribution of temperature on the surface of the 

 tube is shown by a series of curves. An interesting observation 

 made by the author is that phosphorescent light on the surface 

 of the glass, such as Prof. Crookes considered as appearing only 

 at pressures equal to millionth parts of an atmosphere, appeared 

 also at pressures from i'3 to o'8 millimetres, the glass of the 

 tube not belonging to the category of uranic glass, and the 

 phosphorescent light appearing invariably on the calode, even 

 when the direction of the current has been changed. — Prelimi- 

 nary report on the influence of compression of iron and steel on 

 their magnetisation, by P. Bakhmetieff. — On the hail of July 11, 

 1884, at Kharkoff, by N. Piltchikoff— a description, with 

 figures, of the hailstones. — On the shock of absolutely rigid 

 bodies, by N. Joukovsky ; being a mathematical critique of the 

 theories advanced on this subject by MM. Matson, Prof. Shiller, 

 at Kieff, and M. < Jarrigou- Lagrange. — On the dilatation of 

 liquids, by M. Avenarius, against Prof. Mendeleeff's formula 

 and in favour of the expression v = a + Clog. (T - /).■ — On 

 the regular forms taken by powders, by Th. Petrushevski. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, January S. — "Experimental Researches in 

 Magnetism.'' By Prof. J. A. Ewing, B.Sc, F.R.S.E., Uni- 

 versity College, Dundee. Communicated by Sir William 

 Thomson, F. k.S. 



The paper describes in detail experiments of which preliminary 

 notices have already been published in the Proceedings of the 

 Royal Society, vol. xxxiv. p. 39, and in the Philosophical Maga- 

 zine, November, 18S3. The experiments relate to — 



(1) The magnetic susceptibility of iron and steel, the form of 

 the magnetisation curve, and the changes of magnetism caused 

 by cyclic changes of magnetising force. 



(2) The influence of vibration on magnetic susceptibility and 

 retentiveness. 



(3) The influence of permanent strain on magnetic suscepti- 

 bility and retentiveness. 



(4) The energy expended in producing cyclic changes of mag- 

 netisation. 



(5) The ratio of residual to total induced magnetism. 



(6) The changes of induced and residual magnetism caused by 

 changes of stress. 



(7) The effects of constant stress on magnetic susceptibility 

 and retentiveness. 



(S) The changes of magnetism caused by changes of tem- 

 perature. 



(9) The effect of temperature on magnetic susceptibility. 



The experiments were conducted on pieces of metal which 

 gave as near an approach to the condition of uniform magnetisa- 

 tion as is practically attainable. 



Curves are given which show the behaviour of iron and steel 

 in various states of temper when subjected to a first application 



