526 



NATURE 



[January 7, 19 15 



wood parenchyma round the vessels is to be regarded 

 as a glandular sheath for the secretion of carbo- 

 hydrates into the transpiration stream. The medul- 

 lary rays store these materials and convey them to the 

 sheaths. 



Paris. 

 Academy of Sciences, December 28, 1914. — M. P. 

 Appell in the chair. — Paul Appell : The principle of the 

 minimum of the energy of accelerations and the sub- 

 stitution of force linkages. — Ph. A. Guye and F. E. E. 

 Germann : The influence of the gaseous impurities of 

 silver on the values of the atomic weights determined 

 by the classical methods ; the atomic weights of 

 chlorine and of phosphorus. Referring to their recent 

 determinations of the amounts of carbon monoxide 

 and water in highly purified silver found after fusion 

 in hydrogen, it is shown that the use of such silver 

 in atomic weight determinations would lead to a value 

 about 0005 too high, a negligible quantity. The 

 effect of such an error on other atomic weights based 

 on silver is discussed. The resulting corrections are 

 of the order of i to 2 units in the second decimal place, 

 exceptionally 3 to 4 units. Phosphorus, for example, 

 would be lowered from 31028 to 31 007. — F. Gonnessiat : 

 The eclipse of the sun : results.— A. Buhl ; The inter- 

 vention of the formulae of Riemann, Stokes, and Green 

 in the extensions of Abel's theorem. — Luclen Godeaux : 

 Triple surfaces endowed with a finite number of points 

 of diramation. — R. Marcille : Determination of the 

 Hiibl iodine number in alcoholic liquids. The iodine 

 numbers of essential oils. The determinations must 

 be made in liquids containing a definite alcohol con- 

 centration, and the reaction must be carried out in the 

 dark. — Henry Hubert : The diabase veins of western 

 French Africa. — D. Eginitis : The recent earthquakes 

 at Thebes. The village of Thebes was ruined by an 

 earthquake on November 17, 1914, this being the 

 fourth time this has happened within the last sixty- 

 two years. The seismographs at Athens due to this 

 earthquake are discussed. The three violent shocks 

 of the first day have been followed by a series of 

 smaller ones. Up to the middle of December more 

 than 500 shocks coming from the same epicentre have 

 been recorded at the Athens Observatory. This long 

 duration is one of the characteristics of earthquakes in 

 this part of Greece.— E. M. Mattel : The Mammoth 

 Cave, Kentucky. Diagrams of four transversal sec- 

 tions are shown, showing the arrangement of the three 

 principal stages. — L. G. Seurat : The morphology of 

 the female genital apparatus of the Spiruridae. 



BOOKS RECEIVED. 



Home University Librar>\ Nerves. By Dr. D. F. 

 Harris. Pp. 256. (London : Williams and Norgate.) 



IS. 



Atlas of Japanese Vegetation, with Explanatory 

 Text. Edited by Prof. M. Miyoshi. Set xv. 102-7. 

 (Tokyo : Maruzen Co., Ltd. ; London : W. Wesley 

 and Son.) 



Scientific Method in Philosophy. By Hon. B. 

 Russell. (Herbert Spencer Lecture.) Pp. 30. (Ox- 

 ford : Clarendon Press.) is. 6d. net. 



Flora of Jamaica. Vol. iii. Dicotyledons. Families 

 Peperaccae to Connaraceae. By Drs. W. Fawcett 

 and A. B. Rendle. Pp. xxiv + 280 + 5 plates. (Lon- 

 don : British Museum (Natural History); Longmans 

 and Co.) 15s. 



All about Leaves. By the late F. G. Heath. Pp. 

 1x4-228. (London : Williams and Norgate.) 4s. 6d. 

 net. 



A Course of Pure Mathematics. By G. H. Hardy. 

 Second edition. Pp. xii4-443. (Cambridge University 

 Press.) 125. net. 



Commission Electrotechnique Internationale. Fasc. 



NO. 2358, VOL. 94] 



27. Symboles Internationaux. Pp. 15. (London : 

 Waterlow and Sons, Ltd.) 2s. 



Animal Experimentation and Medical Progress. By 

 Prof. W. W. Keen. Pp. xxvi4-3i2. (Boston and 

 New York : Houghton, Mifflin and Co.) 7s, 6d. net. 



DIARY OF SOCIETIES. 



FRIDAY, January 8. 



Royal Astronomical Society, at 5.— Total Eclipse of the Sun, 1914, 

 August 21: Preliminary Account of Observations at Minsk, Russia: 

 H. S. Jones and C. R. Davidson. — Preliminary Report on the Total 

 Eclipse of 1914, August 21, Observed at HernOsand, Sweden: Rev. A. L. 

 Cortie.— Total Solar Eclipse, 1914, August 21 : Report on an fc-xpedition 

 from the Solar Physics Observatory, Cambridge, to Theodosia, Russia : 

 H. K. Newall.— Total Solar Eclipse of 1914, August 21 : Report on the 

 Kiev Expedition : A. Fowler, E. H. Hills, and W. E. Curtis. — Reply to 

 Prof. Sampson's Objections to the Hypothesis of a Sun-spot Swarm : 

 H. H. Turner. -A New Method of Discovering Periodicities: J- J- 

 Craig.— The Influence of Local Atmospheric Cooling on Astronomical 

 Refraction : Sir J. Larmor. 



Geologists' Association, at 8.— The Value of Graptolites to the Strati- 

 graphical Geologist : Gertrude L. Elles. 



MONDAY, January ii. 



Royal Gkographical Society, at 8.30.— The Adai Group of the 

 Caucasus : H. Racburn. 



TUESDAY, January 12. 



Institution of Civil Engineers, at 8.— The Lateral Pressure and 

 Resistance of Clay, and the Supporting Power of Clay Foundations : 

 A. L. Bell. 



THURSDAY, January 14. 



Institution OF Electrical Engineers at 8.— The Shape of the Pressure 

 Wave in Electrical Machinery: Dr. S. P. Smith and R. S. H. Boulding. 



CONTENTS. PAGE 



Lead Poisoning. By T 499 



Vegetable Tannins. By E. S 499 



Wireless Telegraphy. By J. A. F 500 



Translations of Poincare on Method. By <^. ... 501 



New Chemical Books. By J. B. C 502 



Our Bookshelf . •. 504 



Letters to the Editor : — 



Ihe Appley Bridge Meteorite. {Illustrated.)— 



William C. Jenkins 505 



A Suggested Definition of Magnetic " Permanence." 



—J. R. Ashworth 506 



European Aerodynamical Laboratories. {Illustrated.) 506 

 Chemistry of Wheat and Flour. By Dr. E. F. 



Armstrong 5o8 



The Food of British Wild Birds. By Walter E. 



Collinge 509 



Attempts to Manufacture Scientific Discovery. By 



Sir Ronald Ross, K.C.B., F.R.S 512 



Notes . ■ 513 



Our Astronomical Column :— 



Bright Meteors of December 29 and 31 51? 



Water Vapour in Mars's Atmosphere 51* 



A Second Harvard Map of the Sky 518 



The Short-Period Variable, SZ Tauri 5 '8 



One Hundred New Double Stars 518 



Prize Awards of the Paris Academy of Sciences 



for 1914 518 



Economic Geology in the United States 519 



Iron in Ancient India 520 



An AU-Metal Diving Dress, {illustrated.) .... 520 



Geophysical Memoirs. By W. W. B 521 



The Artificial Production of Vigorous Trees. {Illus- 

 trated.) tt'- ■ J ^^^ 



Optical Glass and Scientific Instruments: United 



Kingdom Imports and German Exports .... 523 



University and Educational Intelligence 524 



Societies and Academies S^S 



Books Received 5^6 



Diary of Societies S^o 



Editorial and Publishing Offices: 



MACMILLAN & CO., Ltd., 



ST. MARTIN'S STREET, LONDON, W.C. 



Advertisements and business letters to be addressed to the 



Publishers. 



Editorial Communications to the Editor. 



Telegraphic .Address: Phusis, London. 

 Telephone Number : Gerrard 8830. 



