20 



NATURE 



[March 7, 19 18 



— and presumably a considerable amount of invisible 

 work on the valley bottom — although it must have been 

 v\,-holly submerged in Lake Missoula for two or three 

 score, if not for four score, miles. — J. F. McClendon : 

 The effect of stretching on the rate of conduction in 

 the neuro-muscular network in Cassiopeia. Appar- 

 ently stretching the nerve does not change the rate.^ — 

 B. M. Davis : A criticism of the evidence for the muta- 

 tion theory of I>e Vries from the behaviour of species 

 •of OEnothera in crosses and in selfed lines. Although 

 inost of . the genetical work on Qtnotheras has 

 not been interpreted by the Mendelian system 

 of notation, there is clear evidence of order 

 in the results in inbreeding and crossing; the 

 difficulty has been to discover and to isolate simple 

 material in the confusion of mixed and impure forms 

 of these plants. — W. D. Harkins and L. Aronberg : The 

 spectra of isotopes and the vibration of electrons in 

 the atom. The spectra of isotopes have been previously 

 reported as identical within the errors of measure. The 

 authors find, however, a slight difference. The wave- 

 length of uranio-lead was very sli^htlv lont/er than that 

 of the ordinary lead. — J. F. McClendon : The effect of 

 oxygen tension on the metabolism of Cassiopeia. 



BOOKS RECEIVED. 



Cambridge Papers. By W. W. Rouse Ball. Pp. 

 vi + 326. (London : Macniillan and Co., Ltd.) 6s. net. 



Infinitesimal Calculus. By Prof. F. S. Carey. Sec- 

 tion I. Pp. xiii+144 + v. (London: Longmans and 

 Co.) 6s. net. 



Mathematical Papers for Admission into the Rpyal 

 Military Academy and the Roval MiHtarv College for 

 the Years 1008-17. Edited by R. M. Milne. (Lon- 

 don : Macmillan and Co., Ltd.) 75. 



The Science of Power. Bv B. Kidd. ■ Pp. 306. 

 (London : Methuen and Co., Ltd.) 6s. net. 



DIARY OF SOCIETIES. 



THURSDAY. March 7. 



Royal Society, at 4.30.— Numerical Solution of Tntesral Equations- 

 Prof. K. T. Whittaker.— (r) Cesaro Convergence of RestricteH Fourier 

 Series; (2) Non-Harmonic Trigonometrical Series: Prof. W. H. Young. 

 —The Electro-magnetic Inertia of the Lorentz Electron : Prof. n. A. 

 Srhott.— Researches on Growth and Movement in Plants by Means of the 

 Hieh Magnification Crescog'aph : Sir J. C. Bose. 



Institution of Electricai, EKfiiNEERS, at 6.— The Control of Large 

 Amounts of Power: E. B. Wedmore. 



Institution of Mining and Metallurgy, at 5.^10.— Tb- Application r.{ 

 Charcoal to the Precipitation of Gold from its Solution in Cj'anide : H R. 

 Edmands.— Blast-furnace Smelting; of Stibnite, with considerations on'the' 

 Metalkirey_ of Antimony: W. R. Schoeller.-A "Responsive" Shaft 

 Signal Device : B. Angwin. 



LiNNEAN Society, at s.-(i) The Mimetic and Mendelian Relationships of 

 the White Admirals of North America (with Lantern Slides). (2) A 

 New Mimetic Form of Pseu^acraea ^ce^f / (Dewitz) from ex-German East 

 Africa, with other African Mimics of Danaida chrtsippus (Linn ) ■ Prof 

 E. B. Poulton.— Mimetic Species of the African Nyi^phaline Genus Pseud- 

 acra;.-i and Lycaenid Genus Min.acraea, together with their Acr»ine and 

 Uanaidme Models and Some of their Co-mimics : Lord Rothschild 



Chemical Society, at 8.— Atomic and Molecular Numbers • H S Allen — 

 The Subbromide and Suhchloride of Lead : H. G. Denham.-Studies'on 

 the Phenylsuccinic Acid Series. VI., Racemisation Phenomena observed 

 during the Investigation of the Optically Active Phenvl- and Diphenvl- 

 succimc Acids^ and their Derivatives: H. Wren.-The Alkaloids of 

 Ipecacuanha. Ill : F. L. Fymjn -Phe Constitution of the Oisaccharides. 

 II., Lactose and Melibiose: W. N. Haworth and G. C. Leitch. 

 FRIDAY, March 8. 



Roval Institiitiov, at s-So.-Vibrations : Mechanical, MusicaJ, and Elec- 

 trical : Prof. E. H. Barton. 



Royal Astronomical •Society, at 5.— Double Stars measured at the 

 Cape Ob'^ervatory : J. Vofite. — Planetary Motion in Space-Time of any 

 Constant Curvature, according to the generalised Principle of Relativity • 

 L. .Silberstein.-The number of Stars of different Magnitudes in 

 the Hyderabad .A.strographic Catalogue. II.,' Zone - 18° : R J 

 Pocock.—Micrometrical Measures of Thirty.-one new Double Stars ■ F C 

 Leonard.— Errata in Van Biesbroeck's Third Series of Measures of Double 

 Stars: E. Do .little.-Solar Prominences, ,817 : G. J. Newbegin.-The 

 Early History of the Solar System : H. }-Srs:ys..—Proial,le Paiers 

 The Measurement of Time to the Thousandth of a Second : K. A. Samp- 

 son.— The .Secular Acceleration of the Sun as determined from Hippar- 

 chniss Equinox Observations, wilh a note On Ptolemy's False Equinox: 

 J. K. Fotheringham. 

 Physical Society, at 5.— The Asymmetrical Distribution of Corpuscular 

 Radiation Produced by X-rays: E. A. Owen.— On "Air Standard" 

 Internal-Combustion Engine Cycles and their Efficiencies: Prof C H 

 Lees. 



SATURDAY, March 9. 

 Royal Institution, ai 3.-PrMblems in Atomic Str 

 I hoaison. 



: Sir J. J. 



MONDAY, March ii. 

 Royal Geocraphical Society, at S.30.— .My Second Year's Journey in 



Kansu : Reginald Farrer. 

 Society of Engineeks, at 5.30 -Concrete Mi.vtures for Ferro-concrete' 



Work : 1. J. Uueritte. 



TUESDAY, March 12. 

 at 3.— Ibe Stifling of Children's Health: Dr. 



Royal Institut 

 Leonard Hill. 



Institution of Civil Engineer.s, at 5.30.— Kinematograph Films IHus- 

 trating Water-power Works in Canada : Prof. J. C. McLennan. 



Roy.\l Anthropological I.nstitute and Prehistoric Society of 

 Last Anglia (Joint Meetings).— The Prehistoric Society of East Anglia, 

 at 3-— Presidential Address : Our Neighbours of the Neolithic Period : 

 K. A. Smith.— Royal Anthropological Institute, at 5. is.— The Age of 

 Some Megalithic Structures in the Mediterranean Area : H. J. E. Peake. 

 WEDNESDAY, March 13. 



Royal Society of Arts, at 4.30— Ypres and other Flemish Cities Befor* 

 and Since the War (in Enelish) : Paul I ambotte. 



Institute of Met als, at 8.— Presidential Address. 



British Association Geophysical Discussions (Royal Asironomical 

 Society), at 5.— Auroras and the Electrical State of the Uppsr Atmasphere : 

 Dr. C. Chree, Profi A. Fowler, the Hon. R. J. StruU, and Others. 

 THURSDAY, March 14. 



RovAt, Society of Arts, at 4.30.— English Commerce with India, 1608- 

 1658 : William Foster. 



Institute of Metals, at 4.— The Relationship between Hardness and 

 (Ijonstitution in the Copper-rich Aluminium-Copper Alloys : J. Neill 

 Greenwood. — Aluminium-Bronze Die Casting : H. Whittaker and 

 H. Rix.— On Gr>in Size; Dr. G. H. Gulhver.-l.ead-Tin-Antimony 

 Allojrs : Owen W. Ellis.— An Investigation on Unsound Castings of 

 Admiralty Bronze (88 : 10 : 2): Cause and Remedy: Prof. H. C. H. 

 Carpenter and Miss C. F. Elam. 



Optical Society (Imperial College of Science and Technology), at 8.— 

 The Detection of Ghosts in Prisms : T. Smith, 

 FRIDAY, March 15. 



Institution gf Mechanical Engineers, at 6. 



SATURDAY, March 16. 



Royal Institution, at 3.— Problems in Atomic Structure: Sir J. J. 

 Thomson. 



CONTENTS. PAGE 



Cambridge Standards of Value . . . . i 



Webb's "Celestial Objects." By W. W. B 2 



Our Bookshelf 3 



Letters to the Editor:— 



The Stimulation of Plant-growvh by Electric Fields. 



—J- L. . . . . 4 



Photographic Determination of the Al'it»ide of the 



Aurora of December 16, 191 7, in Christiania. 



{Illustrated.)— Prof. Carl Stormer . . 4 



Eastern and Western Asymmetry of Solar Prominences. 



— Albert Alfred Buss . .5 



A Graham Bell Telephone Memorial. (Illustrated.) 



By A. R 5 



The Radio-activity of Some Canadian Mineral 



Springs. By F. S 6 



Prof. E. A. Letts 7 



Notes . 8 



Our Astronomical Column : — 



Encke's Comet and Others 12 



Nebulosity about Nova Pers«i (1901) 12 



The Egyptian Government Almanac . 12 

 Sir Alfred Keogh and the Army Medical Services. 



By H. G. P. . . 12 



The Departmental Report on Salaries in Elementary 



Schools 13 



Meteorology and Exact Thermometry ... .14 



Gravitation and the Principle of Relativity. By 



Prof. A. S. Eddington, F.R.S. 15 



University and Educational Intelligence . . 17 



Societies and Academies 18 



Books Received , 20 



Diary of Societies 20 



Editorial and Pnhlishing Offices: 



MACMILL.\N AND CO., Ltd., 



ST. M.\RTIX'S STREET, LONDON, \V.C.2. • 



dvertisctnents and business letters to be addressed to the 

 Pnblishers. 



Editorial Connniinications to the Editor. 

 Telegraphic Address • Piu'sis, London. 



Telephone Xtiwber : (.i:kk\k1) ^830.' 



NO. 2523, VOL. lOll 



