264 



NA TURE 



[July 15, 1897 



suffice to account for the sign and amount of the dissymmetry 

 of Hall's effect, {b) On the relation between crystal direction 

 and resistance, increase of magnetic resistance and Hall's 

 effect. Hall's coefficient is not the same for a number of 

 small plates, cut, in different directions, out of the same bismuth 

 crystal. (The ratio of the maximum to the minimum value was 

 once found to be nearly 8. ) The amount of the increases of 

 magnetic resistance in the plare _L magnetisation is determined 

 by the same angle. (The ratio of maximum to minimum some- 

 times amounts to more than 2.) 



May 29. — Prof. Korteweg, on certain oscillations of higher 

 order and abnormal intensity that can occtir in mechanisms of 

 several degrees of freedom. It was shown that, under certain 

 conditions some of the coefficients, and with them, also, the 

 respective oscillations are of abnormal magnitude. The author 

 developed the theory of these abnormal oscillations of higher 

 order. He discussed the part they may perhaps play in the 

 oscillations of a mechanism, in the theory of light, and also in 

 the spectra of gases, if Prof. V. A. Julius's view, that the internal 

 motion of molecules may be conceived as oscillations of moderate 

 intensity about a state of equilibrium, be right. — Mr. Eykman, 

 treating of measures for checking beri-beri, communicated the 

 results of researches made by the Medical Inspector Vorderman, 

 concerning the relation between the nature of the rice-diet and 

 the occurrence of beri-beri in the prisons in Java. From these 

 researches it appears that the disease occurs principally in those 

 prisons where the rice is eaten completely peeled, and, on the 

 contrary, hardly ever in those where the prisoners eat half- 

 peeled rice (?■.(?. rice still covered with the " silvery " pellicle "). 

 This inquiry was suggested by similar results obtained by the 

 author when studying k disease of domestic fowls, resembling 

 beri-beri. — Prof, van der Waals presented, on behalf of Mr. P. 

 Zeeman, further observations by the author concerning the 

 change of spectrum lines by magnetism. Along the lines of 

 force a blue cadmium line was doubled, across the lines of force 

 it was trebled by the action of magnetism, the polarisation of 

 the middle and that of the edges of a broadened line in the 

 latter case being perpendicular to each other. This is in perfect 

 harmony with Lorentz's theory of the effect. — Prof, van der 

 Waals next read a paper by Mr. Zeeman, on a new experiment 

 concerning anomalous wave propagation. Gouy's theory of the 

 subject {Ann. de Chim. et dc Phys., vi. 24) was confirmed by 

 means of a combination of a lens and a plate of Iceland spar 

 cut so as to have the optical axis in their planes. Transmitted 

 light was used. The experiment has some advantages over one 

 devised by Joubin for demonstrating Gouy's theory, the principal 

 one being the possibility of having any value for the initial 

 phase difference of the two interfering pencils in the central part 

 of the field. — Prof, van der Waals also presented, on behalf of 

 Prof. Kamerlingh Onnes, (a) a paper, by Mr. A. van Eldik, on 

 measurements of the capillary ascent of the liquid phase of 

 a mixture of two substances in equilibrium with the gaseous 

 phase ; (b) a paper, by Mr. L. H. Siertsema, on the influence 

 of pressure upon the natural rotation of the plane of polarisation 

 in solutions of cane sugar. The measurements mentioned on 

 a previous occasion have been continued with a concentration of 

 27*84 gr. in 100 cc, and have yielded a variation of 0-270 

 per cent, for 100 atm. If Tammann's hypothesis concerning the 

 equivalence of internal and external pressure is adopted, these 

 results may be compared with those respecting the variation of 

 the specific rotation capacity by a variation of concentration, or 

 by the addition of an inactive salt. The comparison shows that 

 the phenomenon is probably more complicated than Tammann's 

 hypothesis renders it. — Prof. Lorentz presented, for publication 

 in the /V^r^^o'wz^.f, a paper entitled " On the resistance which a 

 liquid current naeets with in a cylindrical tube." — Prof. Bakhuis 

 Roozeboom presented, on behalf of Dr. E. Cohen, a paper on 

 the inversion constant of sugar in an aqueous solution. This 

 constant varies with the concentration of the sugar solution. 

 This difference can be removed if, in calculating the concentration 

 of the inverting acid, the total volume is not used, but if the 

 volume of the sugar in the solution is deducted from it. In 

 this way there arises perfect agreement with the theoretical 

 process of the reaction, as Dr Cohen demonstrated with ex- 

 periments made by Ostwald, and observations made by himself, 

 with acids of |^ - ^If norm. — Prof. J. C. Kapteyn contributed 

 a communication on the distribution of stellar velocities, being a 

 sequel to a former paper on the same subject (May 1895). The 

 author shows how the magnitude of the proper motions may be 

 made to contribute to the derivation of the law of velocities, as 



well as their direction. The author further shows that the most 

 serious anomalies which remain in the distribution of the direc- 

 tions of the proper motions, even as computed with the best data 

 available for the precession and the position of the apex, will 

 disappear for by far the greater part, by assuming a constant 

 error, or an error proportional to the cosine of the declination, 

 in Auwers' proper motions in declinations. 



BOOKS, PAMPHLET, and SERIALS RECEIVED 



Books. — Die .Mechanik des Wekalbs : Dr. L. Zehnder (Freiburg i.B., 

 Mohr). — Electricity and Magnetism for Beginners : F. W. Sanderson 

 (Macmillan).— Hallucinations and Illusions : E. Parish (Scott).— Wild 

 Flower Lyrics : J. Rigg (A. Gardner). — Electric Smelting and Refining : 

 Dr. W. Borchers, translated, with additions, by W. G. McMillan (Griffin). 

 — Lehrbuch der Erdkunde : Dr. W. Ule, i Teil (Leipzig, Freytag).— 

 The Ancient Stone Implements, Weapons and Ornaments of (3reat Britain : 

 Sir J. Evans, and edition (Longmans). — Reform of Chemical and Physical 

 Calculations : C. J. T. Hanssen (Spon). 



Pamphlet. — On the Synthesis and Molecular Constitution of Dead and 

 Living Proteid : Dr. P. W. Latham (Cambridge, Deighton). 



Serials. — Traits de Zoologie, Fasc. .xi. and xvi. (Paris, Rueflf). — Jahr- 

 biich der K. K. (ieologischen Reichsanstalt, 1896, 3 u. 4 Heft, and 1897, 

 I Heft (Wien). — Mind, July (Williams). — American Journal of Science, 

 July (Newhaven). — Journal of Anatomy and Physiology, July (Griffin). — 

 Geological Magazine, July (Dulau). — Lean's Royal Navy List, July 

 (Witherby). — Plantae Europae, Tomus ii. fasc. i. (Leipzig, Engelmann). — 

 Brain, Parts 77 and 78 (Macmillan). 



CONTENTS. PAGE 



The Ancient Volcanoes of Britain. By Dr. Chas. 



Barrois 241 



American Mathematics. By Prof. A. G. Greenhill, 



F.R.S 244 



Osteology 245 



Our Book Shelf:— 



Kahlbaum : " Studien liber Dampfspannkraftmes- 



sungen" 246 



Wright: "The Induction Coil in Practical Work, 



including Rontgen Rays " 246 



Smith : " The Calculus for Engineers and Physicists." 



— G 247 



Stoll : " Zur Zoogeographie der landbewohnenden 



Wirbellosen " 247 



" Transactions of the American Microscopical 



Society " 247 



" Experimental- Untersuchungen liber Elektricitat von 



Michael Faraday" 247 



Letters to the Editor:— 



The Fullerian Professorship of Physiology at the Royal 



Institution.— Dr. Augustus D. Waller, F.R.S. 248 

 Streaming Movements of the Protoplasm in Pollen of 



Flowers.— H. B. Potter 248 



Sensitiveness of the Retina to X-Rays. — Guy Oliver 



Harrison 248 



Distant Stars.— Albert Collison 248 



Sound of Distant Firing. — C. Mostyn 248 



Blackbird's Nest appropriated by a Wagtail — F. C. 



Constable 248 



The Etiology of Yellow Fever. By Dr. E. Klein, 



F.R.S 249 



The Variable Star 77 Aquilse. By Prof. R. 



Copeland, Astronomer Royal for Scotland . ... 249 

 British Association Toronto Meeting. III. By 



Prof. A. B. Macallum 250 



The Challenger KVonm. {With Portrait.) W. A. H. . 251 



Notes 251 



Our Astronomical Column: — 



Jupiter's Satellites 255 



The Constant of Aberration 255 



Catalogue of 480 Stars for Zone Observations between 



- 20° and - 80° 255 



Latitude Observations at the U.S. Naval Observatory, 



Washington 256 



Appearance of D' Arrest's Comet 256 



Species or Subspecies? By R. Lydekker, F.R.S. . 256 

 Recent Investigations into the Numerical Value of 

 " The Mechanical Equivalent." {With Diagram.) 



By E. H. Griffiths, F.R.S 258 



The Action of Light on Diastase 259 



University and Educational Intelligence 260 



Scientific Serials 260 



Societies and Academies 260 



Books, Pamphlet, and Serials Received 264 



NO. 1446, VOL. 56] 



