12 



NATURE 



[July 29, 189; 



for i/200th of a second, during which the back E.M F. of the 

 poles was opposed to a single cell. The effect of the cooling 

 of the carbons was thus eliminated, and the conclusion is 

 drawn from the experiments, that the arc behaves exactly 

 like an ordinary resistance, and presents no counter electro- 

 motive force comparable in magnitude to the difference of po- 

 tential of the carbon poles. — On the action of electric charges 

 ypon the discharging power given to air by the X-rays, by M. 

 Emile Villari. — On the properties of gases traversed by the 

 X-rays, and on the properties of luminescent or photographic 

 bodies, by M. G. Sagnac. A connection is traced between the 

 rapidity of discharge of a conductor by the gases exposed to the 

 X-rays, and the luminescence of the same gases. — The penetra- 

 tion of metals by the Rontgen rays, by M. Radiguet.— On the 

 spectrum of carbon, by M. A de Gramont. A method is de- 

 scribed for obtaining the spectrum of carbon free from foreign 

 lines. Shortintense sparks are passed through an alkaline car- 

 bonate, kept in a pasty state by a red-hot platinum spiral, the 

 whole being placed in an atmosphere of dry carbonic acid or 

 hydrogen. The spectrum obtained was identical with that given 

 by Siberian graphite, with the exception of a doubtful ray in the 

 red exhibited by the latter. Retort carbon, in spite of careful 

 purification, gave numerous rays attributable to impurities such 

 as calcium, barium, and iron. — Action of copper hydrate upon 

 solutions of .silver nitrate, by M. Paul Sabatier. The precipi- 

 ^tation of cupric nitrate solutions by silver oxide appears to give 

 .rise to a basic nitrate of copper and silver. — Hydrobenzamide, 

 .amarine, and lophine, by M. Marcel Delepine. A thermo- 

 . chemical paper. — New' syntheses with cyanosuccinic ether, by 

 M. L. Barthe. — On some combinations of phenylhydrazine and 

 metallic nitrates, by M. J. Moitessier.— On the aloins, by M. E. 

 Leger. — The function of auto-intoxication in mechanism of the 

 death of animals deprived of their subrenal capsules, by M. D. 

 Gourfein. — Nuclear purification at the commencement of onto- 

 genesis, by M. L. Cuenot. — Variations of the lower fungi under 

 the influence of the medium, by M. Julien Ray. — On the germi- 

 nation of grains of Leguminosse containing parasitic larvoe, by 

 M. Edmond Gain. 



Amsterdam. 

 Royal Academy of Sciences, June 26. — Prof, van de 

 Sande Bakhuyzen in the chair. — Prof. Bakhuis Roozeboom, on 

 melting-lines of systems of two and three organic substances. — 

 Mr. Hamburger read a paper on a method of separation and 

 quantitative determination of diffusible and non-diffusible alkali 

 in serous fluids. — Prof, van Bemmelen made, on behalf of F. 

 Schreinemakers, a communication concerning an inquiry into 

 equilibriums in systems of three components in which two liquid 

 phases occur. — Prof Kamerlingh Onnes presented a paper, by 

 Mr. E. van Everdingen, on the Hall effect and the increase of 

 magnetic resistance in bismuth ; and, on behalf of Mr. A. van 

 Eldik, measurements of the capillary ascent of the liquid phase 

 of a mixture of two substances in equilibrium with the gaseous 

 .phase. — Prof. Haga presented, on behalf of Dr. C. H. Wind, a 

 - contribution entitled " On the influence of the dimensions of the 

 source of light in Fresnel's diffraction phenomena, and on the 

 diffraction of X-rays " (second paper). In this paper the theory 

 developed in the first paper was applied to the case of a narrow 

 rectangular screen for obstacle. The shadow roust consist 

 principally of a nucleus, surrounded by maxima, or else — if the 

 screen is very narrow — an illuminated space in the middle be- 

 tween minima, again followed by maxima. The distance of 

 these maxima and minima from each other renders it possible to 

 estimate the wave-length. Experiments with rays of light, as 

 well as with X-rays, yielded diffraction images as expected ; and 

 from this it follows — at any rate, that in the case of X-rays — \ is 

 very small. — Prof. Franchimont, on the action between methyl- 

 nitramine and potassium nitrate in an aqueous solution at the 

 ordinary temperature. The principal products are potassium 

 nitrate, nitrogen and methylalcohol, besides dimethylnitra- 

 mine and isodimethylnitramine. Secondary products are, 

 among others, a little carbonic acid and a very volatile sub- 

 stance with a strong isonitril smell. The principal reaction is 

 regarded by the author as an addition of methylnitramine to 

 nitrous acid, followed by a decomposition of the product into 

 nitric acid and diazomethyl hydrate ; the latter then yields nitro- 

 gen and methylalcohol, and at the same time methylates a 

 small portion of the methylnitramine. The author further 

 states that all acid and all neutral aliphatic nitramines, and also 

 nitro-urea, when treated with zinc in a solution of acetic acid, 

 to which a naphhtylamine, dimethylaniline, aniline, metaphenj 1- 



NO. 1448, VOL. 56] 



enediamine. &c., yield colouring matters, and that these 

 reactions c'osely resemble those of nitrous acid, though an 

 examination ot the colouring matters themselves gives rise to 

 doubt whether they are due to those reactions. — Prof, van der 

 Waals presented : \a) On behalf of Prof. C. A. J. A. Oudemans, 

 a paper in which the author publishes the finding of some fungi, 

 hitherto unknown and injurious to agriculture, as Brachyspora 

 pisi on the leaves of green peas {Pisum sativum), Marsonia 

 secalis on the leaves of rye {Secale cereale), Hendersonia gros- 

 sularice on the leaves of the gooseberry {Kibes g7-ossularia), and 

 Ftisicladiuvi fa^opyri on the leaves of buckwheat {Fagopyruni 

 esculenhim). The author further points out that the names 

 Hebninthosporiiim gramineum, Eriksson, ZT^/w. /<;r£J, Sacc. , and 

 Hehn. gramineufii, Rabh., are synonymous ; and that the last- 

 mentioned, being the oldest, ought to be retained ; and finally 

 describes a new genus of Verpa, growing in Java on refuse of 

 Indigo/era tinctoria, from which the colouring matter has been 

 extracted, and which plant is eaten by the Javanese ; the author 

 calls this genus Verpa indigocala. (b) On behalf of Prof. 

 Lorentz, a paper by Dr. C H. Wind, on the dispersion of 

 magnetic rotation of the plane of polarisation, with a note 

 added by Prof. Lorentz. [c) On behalf of Dr. P. Zeeman, a 

 paper on doublets and triplets in the spectrum produced by 

 external magnetic forces (ii.). 



BOOKS RECEIVED. 



Books.— A Course of Practical Chemistry : M. M. P. Muir. Part I. 

 Elementary (Longmans), — Organic Chemical Manipulation : Dr. J. T. 

 Hewitt (Whittaker). — Geographical Journal, Vol. ix. (Stanford). — A System 

 of Medicine : edited by Dr. T. Clifford Allbutt, Vol. 3 (Macmillan).— The 

 Potentiometer and its Adjuncts : W. C. Fisher (Electrician Company). — 

 Cuirasses et Projectiles de Marine : E. V.-illier (Paris, Gauthier-Villars). 

 Les Huiles Min^rales : F. Miron (Paris, Gauthier-Villars). — Physikalisches 

 Praktikum : E. Wiedemann and H. Ebert, Dritte Verbesserte und Ver- 

 mehrte Auflage (Braunschweig, Vieweg). — La Cure d' Altitude : Dr. P. 

 Regnard Paris, Masson). 



CONTENTS. PAGE 



M. Faye on Cyclones 289 



The Yew 290 



Our Book Shelf:— 



Lauterborn: " Untersuchungen ueber Bau Kerntheilung 



und Bewegung der Diatomeen " 291 



"Journal and Proceedings of the Royal Society of 



New South Wales for 1896" 291 



Demoor, Massart, and Vandervelde : " L'evolution 



regressive en biologic et en sociologie " 292 



" The Geographical Journal " 292 



Letters to the Editor: — 



The Electro-Chemical Equivalent of Silver. — Lord 



Rayleigh, F.R.S 292 



Acetylene for Military Signalling.— A. E. Munby . 292 

 Disappearance of Nitrates in Mangolds. — T. B. 



Wood 293 



Globular Lightning.— Rev. E. Hill 293 



" Bicycles and Tricycles."— R. H. Housman ; C. 



V. Boys, F.R.S 293 



" A Text-book of Histology." — Dr. Arthur 



Clarkson ; The Reviewer .... ... 293 



A Phenomenal Rainbow.— H. Stuart Dove .... 294 



Fire-fly Light.— Dr. Carlo del Lungo 294 



The Evolution of Stellar Systems. By Dr. William 



J. S. Lockyer 295 



Thierry William Preyer 296 



Notes 297 



Our Astronomical Column : - 



New Observations of Venus 300 



The Yerkes Observatory 300 



Resolving Power of Spectroscopes 300 



The Horizontal Gyroscope 300 



Some Problems of Arctic Geology. {Illustrated.) 



L By Dr. J. W. Gregory 301 



Scientific Investigations of the Scottish Fishery 



Board 303 



The Physiology of the Emotions. By Dr. Harry 



Campbell 305 



On the Ascent of Water in Trees. By Francis 



Darwin, F.R.S 2,07 



University and Educational Intelligence 310 



Scientific Serials 3" 



Societies and Academies 3" 



Books Received . 312 



