36o 



NA TURE 



[August i i, 1898 



compounds of tin and antimony. From an alloy of goSn loCn, 

 thecompound CnSn was obtained. Repeated heatinsj and cooling 

 brought the percentage of copper up from 35 to 58. Micro- 

 scopical examination of bearings showed that cushions heated 

 by running, were poor in cubic crystals of the compound SbSnj. 

 Babbits' metal is made amorphous by casting in cold moulds. 

 Axles running on such metal get tinned ; this leads to sticking 

 and heating ; finally recrystallisation sets in, and liquid tin is 

 squeezed out ; while a compact layer of crystals is formed on 

 the axle. Microscopical examination of the metallic deposit 

 from the lubricating oil led to the unexpected result, that 

 metal with crystals of moderate size will develop ball-cushions. 

 Tin is ground to a fine dust by the sharp fragments of the 

 bronze needles, the hard cubes of SbSn., are rounded, 

 undermined, and finally worked up into something like metallic 

 pebbles of microscopical size (008 to O'l mm.). Similar 

 spheroids were obtained from bearings of magnolia metal and 

 of aluminium brass, but not from ordinary brass, nor from grey 

 cast iron. — Prof. Lobry de Bruyn communicated a number of 

 observations on the state of insoluble amorphous substances, 

 which are made to form in gelatine as medium. These sub- 

 stances, which are precipitated from aqueous solutions, remain 

 ■dissolved in gelatine as colloids, and on solidification yield 

 transparent masses. With incident light some exhibit fluor- 

 -escence or light reflexion ; others do not do so, or only very 

 sparingly. — Prof, van de Sande Bakhuyzen made a com- 

 •m-unication on behalf of Dr. E. F. van de Sande Bakhuyzen, 

 •entitled " The motion of the terrestrial pole according to the 

 observations of the years 1890 to 1896." — Prof. Haga, on a five- 

 •cellar quadrant electrometer and the measurements of current 

 intensity carried out with it. A description was given of a five- 

 cellar quadrant electrometer furnished with a damper, con- 

 sisting of a copper cylindrical mantle, moving in a magnetic 

 field. Owing to the great stability and sensitiveness of the 

 instrument, the strength of strong as well as of weak currents 

 could easily be measured to within 01 per cent, by comparing 

 >the potential difference at the extremities of a known resistance 

 with a normal Clark-element. — Dr. C. H. Wind, on the in- 

 fluence of the dimensions of the source of light in Fresnel's 

 'dififraction phenomena and on the diffraction of X-rays (third 

 communication). The diffraction phenomena, modified by the 

 widening of the light slit, were discussed, this time in connection 

 with the optical delusion discovered by the author. By this 

 discovery some difficulties that still remained were cleared 

 up, but the conclusion as to the evidence of the undulatory 

 character of X-rays, which was to be inferred from previous 

 ■experiments, had to be retracted. Finally new experiments 

 were communicated, in which a still faint indication of diffrac- 

 tion of X-rays manifested itself, and from which was inferred, 

 with the greatest possible reserve, 'Yx = O'l to o"2 ;U;U. — Prof. 

 Kamerlingh Onnes (a), on behalf of Dr. E. van Everdingen, 

 jun. , on the galvano-magnetic and thermo-magnetic phenomena 

 in bismuth. Observations were made of the four transverse 

 phenomena in otte plate of bismuth decomposed by electrolysis. 

 The results were compared with those arrived at by Von 

 Ettingshausen and Nernst and with Riecke's theory of electrical 

 and thermal phenomena in metals. Some among them appeared 

 to agree neither with those results nor with the theory in its 

 ^present form, {b) On behalf of Dr. J. Verschaffelt, on the 

 -deviation of De Heen's experiments from Van der Waals's 

 law of continuity. \c) On behalf of Mr. C. M. A. Hartman, 

 on composition and volumes of the coexisting phases of mix- 

 tures of methyl chloride and carbonic acid. The equilibrium 

 between the two phases being established, parts of both are 

 separated, each between two cocks, and then collected in gas- 

 measuring tubes. The densities of the phases are inferred from 

 the volumes of the gas, and the molecular proportions of the 

 components are found by analysing. A remarkable result of 

 the preliminary determinations is that there is a nearly linear 

 relation between the pressure and the composition of the liquid 

 phase, showing that the exponents in Van der Waals's formula 

 for this case are nearly zero. — Prof. Lorentz, on the influence 

 of a magnetic field on radiation. The elementary theory of the 

 Zeeman-effect is not sufficient to account for the phenomena 

 . observed by Cornu, Michelson, Tolver Preston and Becquerel ; 

 it will therefore have to be replaced by a more general one 

 Fortunately, without entering into the details of the mechanism 

 of radiation, it is possible to arrive at some general results con- 

 . cerning the state of polarisation in dift'erent cases. After dis- 



cussing this question, the author shows how (as was suggested 

 to him by Mr. A. Pannekoek) the equations in his paper in 

 Wied. Ann., 63, p. 278, may be made to furnish an explanation 

 of Cornu's quadruplet. This explanation would, however, 

 require a structure of the ^molecules which it seems difficult to 

 imagine. 



GOTTINGEN. 



Royal Society of Sciences. — The Nachrichten (mathe- 

 matico-physical section) for 1898, part I, contains the following 

 memoirs communicated to the Society. 



January 8. — E. Study : Proof of a theorem of Dedekind's. 



February 5. — A. Peter : The anatomical structure of the stem 

 in the ^^v^wi Scorzonera ; contributions (II.) to our knowledge 

 of the Hieracia of Eastern Europe and Asia. 



February 19. — E. Riecke : Theory of galvanism and of heat. 



March 5. — A. Schonflies : A new geometrical method in the 

 domain of differential geometry.— G. Kolossoff : A particular 

 case in the motion of a ^"universal top" whose point of support 

 is free to move in a horizontal plane. — A. Sommerfeld : Re- 

 marks on Hess's case in the motion of a top. 



March 19.— E. Wiechert : Hypotheses subserving a theory of 

 electric and magnetic phenomena. 



April 30. — W. Voigt and L. Januszkiewicz : Observations on 

 rigidity under homogeneous deformation. 



The Proceedings of the Society, part i, 1898, contain 

 reports on the progress made in the publication of Gauss's 

 works, by F. Klein ; on the publication of the great Lexicon 

 of the Egyptian language, hieroglyphic and hieratic, by R. 

 Pietschmann ; and on the oldest papal documents. There is 

 also a sympathetic memoir of the antiquary Wattenbach, by 

 Dr. P. Kehr. 



CONTENTS. PAGE 



The Palaeontology of Vertebrates. By R. L. ... 337 



The Science of Preventive Medicine 339 



A New Text-Book on Elementary Algebra, By 



G. B. M. 340 



The Cuneiform Inscriptions of Western Asia ... 341 



The Nebular Hypothesis 342 



Our Book Shelf:— 



Schmidt: " Das Fern Objektiv " 343 



Gaedicke : " Der Gummidruck " 343 



Speyers : " Text-Book of Physical Chemistry " . . . 344 

 Dufet : " Recueil de Donnees Numeriques Optique " 344 

 Letters to the Editor :— 



Solar Halos.~W. Larden 344 



A Living Toad in a Snake.— Colonel F. W. Major 344 



Phosphorus in Lucifer Matches 345 



German Deep-Sea Expedition in the Steamship 



Valdivia 346 



Through Unknown Tibet. {Illustrated) 347 



Meeting of the British Medical Association, By 



Dr. F. W. Tunnicliffe 349 



Prof. Georg Baur 35° 



The Ben Nevis Observatories 350 



Notes 351 



Our Astronomical Column : — 



Wolfs Comet 35^ 



Dr. Gill on Sir John Herschel 356 



The Paris Observatory 356 



The French Astronomical Society 356 



The Electrical Resistance and Micro-Structure of 



Alloys. {Illustrated.) By Saville Shaw 356 



The Board of Education Bill . 357 



University and Educational Intelligence 358 



Scientific Serial 359 



Societies and Academies 359 



NO. 



1502, VOL. 58] 



