;6o 



NA TURE 



[February 8, 1906 



GOTTINGEN. 



Royal Society of Sciences. — The Nachrichten (physico- 

 niathematical section), parts iv. and v. for 1905, contains 

 the following memoirs communicated to the society : — 



July 8. — Determination of all curves by the translation 

 of which minimal surfaces are generated : P. Stackel. 



July 22. — Outlines of a general theory of linear integral 

 equations, x., Riemann's problems in the theory of func- 

 tions of a complex variable : D. Hilbert. — On finite 

 algebras : L. E. Dickson. — On pyroelectricity in centro- 

 symmetric crystals ; with appendix (October 28) : On the 

 piezoelectricity of centric crystals : W. Voigt. 



August 5. — On the origin of the salt deposits of north- 

 west Germany : A. von Koencn. 



November 25. — Remarks on an essay on the stellate 

 appearance of the stars {Nachrichten, 1905, p. 238). The 

 effect of the background on the estimation of magnitude 

 (e.g. of the moon on the horizon). The " jumping " of 

 the image in vision with the right and the left eye 

 alternately : W. Holtz. — Measurements of the density of 

 the vertical electric conduction-current in free air made 

 during the balloon voyage of August 30, 1905 : H. 

 Gerdien. — The Doppler effect in " Canal-strahlen " and 

 the spectra of positive atomic ions : J. Stark. — Determin- 

 ation of all curves by the translation of which minimal 

 surfaces are generated : G. Scheffers. 



The official communications, part ii., for 1905, of the 

 Nachrichten contain an anniversary address by W. Voigt 

 on hypotheses concerning work. 



DIARY OF SOCIETIES. 



THURSDAY, February 8. 



Royal Society, at 4.30.— On Roche's Ellipsoids and on Allied Problems 

 Rela'ing 10 Satellites: Sir George H. Darwin, K.C.B., K.R.S.— 

 Polarisation in Secondary RSntgen Radiation : Dr. C. G. Barkla.— Ionic 

 Size in Relation to the Physical Properties of Aqueous Solutions : W. R. 

 Bousfield, K.C.— Explosions of Coal-Gas and Air : Prof. I!. Hopkinson.— 

 On Periodicities in Sun spots ; Prof. A. Schuster, F.R.S. — Constants of 

 Explosion of Cordite and of Modified Cordite: Dr. Robert Robertson. 



Institution of Electrical Engineers, at S. — Technical Considerations 

 in Electric Railway Engineering : F. W. Carter {Conclusion 0/ 

 Discussion).— Crane Motors and Controllers: C. W. Hill 



Royal Institution, at 5. — The Significance of the Future in the Theory 

 of Evolution : Benjamin Kidd. 



Mathematical Society, at 5. 30.— Special General Meeting.— Par- 

 titions of Numbers in Space of two Dimensons: Major P. A. 

 MacMal.on.— The Eisenstein-Sylvester extension of Fermat's Theorem : 

 Dr. H. F. Baker. 



FRIDAY, February 9. 



Royal Institution, at 9. — Eclipse Problems and Observations: H. F. 

 Newall, F.R.S. 



Royal Astronomical Society, at 5. —Anniversary Meeting. 



Physical Society, at £. — Annual General Meeting. Address by the 

 President-elect, Prof. J. Perry, F.R.S. 



Royal Geographical Society, at 5 30 (Research Department). — The 

 Ruins of Rhodesia and the Probable Date of Outside Intrusions in East 

 Africa : Discussion to be opened by D. Randall Maclver. 



Malacological Society, at 8.— Annual Meeting.— On Pearl-Oyster 

 Culture and Pearl Fishing : T. H. Haynes.— Irish Molluscs and their 

 Habitats: R. J.Welch. 



Institution of Civil Engineers, at 8. — Electric Driving at the Locomo- 

 tive Works of the North London Railway : R. H. Mackie. 

 SATURDAY, February 10. 



Royal Institution, at 3. — Advances in Microscopy; J. W. Gordon. 

 MONDAY, February 12. 



Royal Geographical Society, at 8.30. — The Geography of the Spanish 

 Armada : Rev. W. Spotswood Green. 



Society of Arts, at 8.— Modern Warships : Sir William White, K.C.B., 

 F.R.S. 



Institution of Mechanical Engineers, at 8. — Graduates* Lecture: 

 The Niagara Power-Stations : Prof. W. C. Unwin, F.R.S. 

 TUESDAY, February 13. 



Royal Institution, at 5. — Food and Nutrition : Prof. W. Stirling. 



Anthropological Institute, at 8.15. — Exbihition of Lantern-slides of 

 Kikuyu Ceremonies: W. Scoresby Routledge. — Exhibition of Kikuyu 

 Ceremonial Images- T. A. Joyce.— Exhibition of Slides of Rude Stone 

 Monuments and Notes on Stone Monuments in Glamorganshire : A. L. 



Institution of Civil Engineers, at 8. — Adjourned Discussion : The 

 Railway-Gauges of India: F. R. Upcott.— Probable Papers: Country 

 Roads.for Modern Traffic : J. E. Blackwall— A Plea for Better Country 

 Roads : G. R. Jebb. 



WEDNESDAY, February 14. 



Society of Arts, at 8.— The Horseless Carriage, 1885-1905 : Claude 

 Johnson. 



THURSDAY, February 15. 



Royal Society, at 4.30.— Probable Papers: The Influence of Increased 

 Barometric Pressure on Man, No. 1 : Dr. L. Hill, F.R.S., and M. 

 Greenwood.— On the Existence of Cell-communications between Blasto- 

 meres : C. Shearer. — Innervation of Antagonistic Muscles. Ninth Note : 

 Successive Spinal Induction : Prof. C. S. Sherrington, F.R.S.— The 



no. 1893, VOL. 72>~\ 



Chemical Constitution of Protoplasm as shown by the Rate of Tissue 

 Disintegration: Dr. H. M. Vernon.— The Development of the Head- 

 Muscles of the Common Fowl (Callus domesticus), together with some 

 Remarks on the Head-Muscles of Reptiles : Prof. F. H. Edgeworth. 

 Chemical Society, at 8.30. — Cuprous Formate : A. Angel. — The Solu- 

 bility of Triphenylmethane in Organic Liquids with which it forms 

 Crystalline Compouuds: H. Hartley and N. G. Thomas.— The Spon- 

 Crystallisation of Supersaturated Solutions : H. Hartley. - 



Preparation and Propertii 

 and A. C. O. Hann — Studi 

 Application of Grignard's 

 McKenzie. 



Tropeines : H. A. D Jowett 

 Asymmetric Synthesis, Part IV., The 

 ction for Asymmetric Syntheses : A. 



Linnean Society, at 8. — The Structure of Isis hi r f<utis : J. J. Simpson. 

 —Note on the Geographical Distribution of the Genus Shortia, Torr. 

 and Gray : B. Daydon Jackson.— Exhibition : Developmental Changes 

 in Zoogioea (with Lantern Slides) : Dr H. Charlton Bastian, F.R.S. 



Society of Art at 4.30. — The Navigable Waterways of India: R. B. 

 Buckley, C.S.I. 



Institution of Mining and Metallurgy, at 8.— Pyritic Smelting: 

 R. C. Alabaster and F. H. Wintle.— The Acme Combined Concentrating 

 Table: L. H. L. Huddart —Stadia in Careful Work : A. H.Webb.— The 

 Detailed Mapping of Sloping Areas: H. R. Sleeman — Sinking, Develop 

 ment and L T nderground Equipment of Deep Level Shafts on the Rand: 

 A. E. PettiL— The Hydraulic Filling of a Coal Seam at Lens, Pas de 

 Calais, France : L. E. Hill and M. Butt. 



FRTDAY, February 16. 



The Passage of Electricity through Liquids: 



:al Engineers, at 8. — Large Locomotive 



Royal Institution, at 9.- 

 W. C. D. Whetham, F.R. 



Institution of Meciian 

 Boilers : G. T. Churchwar 



SATURDAY, February 17. 



lssociation OF Teachers in Technical Institutes (Regent Street 

 Polytechnic), at 7.30. — The Teaching of Mathematics to Engineering 

 Students: G. E. St. L. Carson.— The Teaching of Mathematics to 

 Building Trade Students : H. Bustridge. 



CONTENTS. page 



A New Integral Calculus. By Prof. G. H. Bryan, 



F.R.S 337 



Stimulus and Memory 338 



Economy in Thermal Power Plants. By E. G. C. . 33S 



Materia Medica. By T. A. H 339 



Our Book Shelf :— 



Baumhauer : " Dieneuere Entwickelungder Krystallo- 



graphie " 34° 



Righi : "La Theorie moderne des Phenomenes 



physiques." — R. J. S 340 



Hedges: " Modern Lightning Conductors " .... 340 

 Letters to the Editor :- 



The Inventor of the Nicol Prism. — Prof. Silvanus 



P. Thompson, F.R.S 340 



Result of War affected by Soldier's Stature. — John 



H. Twigg •.....■ 340 



Scintillations produced by the Electronic "3-Rays" 



emitted by Radium. — C. W. R 341 



The Effect of Food on the Colour of Moths.— Prof. 



T. D. A. Cockerell 341 



A Correction.— F. Escombe 341 



A Metrical and Pictorial Record of the Earth's 



History. (Illustrated.) 342 



Some Mammalian Types. (Illustrated.) By O. V. A. 343 

 Miners' Worm. By Prof. Sydney J. Hickson, 



F.R.S 344 



The Royal College of Science 344 



Notes 346 



Our Astronomical Column: — 



Comet 1905*- (Giacobini). (Illustrated.) 351 



Comet 1906a 352 



A New Method of Determining the Moon's Position 



Photographically 352 



A Catalogue of Spectroscopic Binaries 352 



Observations of the Lyrid Meteors, April, 1904 ... 352 

 Report of the Meeting of the Solar Commission at 



Innsbruck 352 



Anthropological Notes 354 



A Gas Calorimeter. (Illustrated.) 354 



The Electric Production of Nitrates from the 

 Atmosphere. By Prof. Silvanus P. Thompson, 



F.R.S 355 



Polar Exploration 356 



University and Educational Intelligence 356 



Societies and Academies 356 



Diary of Societies 360 



