NA TURE 



[November 5, 1908 



ten to fifteen minutes, and during that time can be carried 

 by currents of air about the room. — An infection of the 

 gondi (Ctenodaciylus gondi) with the Leishman or a 

 similar organism : C. Nicolle and L. Manceaux. — The 

 preponderating role of geometry in topographical examina- 

 tions : M. Contremoulins. A discussion of the applica- 

 tion of geometrical principles to practical radiography. 

 The author arrives at the following conclusions : — the 

 distance of the radiating focus from the photographic plate 

 should be constant for all radiographic examinations, the 

 normal incidence ought to be inscribed automatically in 

 the course of the examination on the plate, the attitude in 

 which the subject has been radiographed ought to be men- 

 tioned on the proof, and, whenever possible, two radio- 

 graphs should be taken forming two planes of projection 

 at an angle of 90°. 



GOTTINGEN. 



Royal Society of Sciences. — The Nachi-ichten (physicn- 

 mathematical section), part iii. for 1908, contains the 

 following memoirs communicated to the society : — 



May 16. — The formal relations of quadrilaterals com- 

 posed of circular arcs : W. Ihlenburg. — New develop- 

 ments in linear differential equations : E. Hilb. — A new 

 method of solution of certain boundary-value problems : 

 W. Ritz. — The application of integral equations to the 

 problem of Riemann : E. E. Levi (Pisa). 



June 27. — The influence of a naturally active body on 

 light reflected from it : K. Forsterling. — The decomposi- 

 tion of an empirically given periodic function into series 

 of sines : C. Rung:e. — The reduced difTerential equations 

 of a heavy unsymmetrical top : P. Stackel (Karlsruhe). 



July II. — Researches from the University chemical 

 laboratory of Gottingen, xx. (i) Transformation of 

 nopinone (C,N,,0) into /3-pinene (C,„H,|,), camphene, and 

 camphor (C|„H|,0) ; (2) the alcohols of the terpinene 

 series; (3) the modifications of terpinene: O. Wallach. 



July 25. — Formulae for the reflection of light at a thin 

 metallic film ? W. Voigrt. 



so produced, the 

 Air : Rev. F. J. Ji 

 from R.idium : ! 



On the Osmotic Pressu 



DIARY OF SOCIETIES. 



THURSDAY, November ^. 

 Royal Society, at 4.30.— (O Note on Tidal Bores; (2) Vortices in 

 Oscillating Liquid : The Lord Ravleigh, O.M., Pres. R.S.— Note on Two 

 recently-compiled Calendars of Papers of the Period i6ofi-i8o6 in the 

 Archives of the Roval Soci.-ty : Prof. A. H, Church, F.R.S —On the 

 Generation of a Luminous Glow in an E.\hausted Receiver moving near 

 Field, and the Action of a Magnetic Field on the Glow 

 Residual Gases heing 0.vygen, Hydrogen, Neon and 

 ervis-Smith, F.R.S.— The Rate of Production of Helium 

 war, F.R.S. —The Spectrum of Radium 

 and Sir William Ramsay, K.C.B., F.R S — 

 i of Aqueous Solutions of Calcium Ferrocyanide 

 Part I., Concentrated Solutions: The Earl of Berkeley, F.R.S., F.. G. J 

 Hartley, and C. V. Burton.— The Effect of Pressure upon Arc Spectra, 

 No. 2, Copper : W. G. Duffield —On a Method of Comparing Mutual 

 Inductance and Resistance by the Help of Two-phase .Alternating Currents 

 A Campbell. 

 Chemical Society, at 8.w,— The Direct Union of Carbon and Hydrogen 

 W. A. Bone and H. F. Coward.— The Relation between Absorption 

 Spectra and Chemical Constitution. Part XI , Some Aromatic Hydro- 

 carbons : E. C. C. Baly and W. B. Tuck —Organic Derivatives of 

 Silicon. Part VII., .Synthesis of rf/Sulphobenzylethylisobutylsilicyl 

 O.vide : B. D. W. Luff and F. S, Kipping. -(i) Chlorine Derivatives of 

 Pyridine. Part IX , Preparation .and Orientation of the Dichlor pyridine, 

 m p. 66-70°; (2) Chlorine Derivatives of Pyridine. Part X., Orientation 

 of the Trichloropyridine, m. p. 40-50'' ; (3) Chlorination of Methyl Deri- 

 vatives of Pyridine. 2-Methyl pyridine. Part II. : W. J. Sell— (i) The 

 Triazo-group. Part 'V., Resolution of rt-Triazopropionic acid ; (2) The 

 Triazo-eroup. Part 'VI., Triazoethyl Alcohol and Triazoacetaldehyde : 

 M. O. Forster and H. E. Fierz. 

 LiNNEAN Society, at 8. — Notes on some Parasitic Copepoda, with a 

 Description of a New Species of C hondracanthiis : May E. Eainbridge. — 

 On some Nemerteans from the Eastern Indian Ocean : R. C. Punnett and 

 C. Forster Cooper. — Report on the Echinoderms other than Holothurians 

 collected by Mr. Stanley Gardiner in the Western Parts of the Indian 

 Ocean ; Prof. F. Jeffrey Bell. 

 Rontcen Society, at 8.15.— Presidential Address, The .Amsterdam 

 Congress. 



FRIDAY, November 6. 

 CJfologists' Association, at 8. — On some Norwegian Lakes and Rock- 

 Basins : H. W. Monckton 



TUESDA Y, November 10. 

 Institution .'OF Civil Engineers, at 8.— Glasgow Central Station 

 Extension: L). A. Matheson. 



THURSDAY, November .2. 



Royal Society, at ^.^o.—PtvinUe Papers: The Charges on Ions in 



Gases, and the Effect of Water Vapour on the Motion of Negative Ions : 



Prof. J. S. Townsend, F.R.S.— The Charges on Ions produced by 



Radium : C. E. Haselfoot.— The Occlusion of the Residual Gas and the 



of the Glass Walls of Crookes's Tubes : A. A. Campbell 

 Swinton. — An Investigation of the Anatomical Structure and Relationships 

 of the Labyrinth in the Reptile, the Bird and the Mammal : Dr. A. A. 

 Gray.- The Natural Mechanism for Evoking the Chemical Secretion of 

 the Stomach (Preliminary Communication) : Dr. J. S. Edkins and Miss 

 M. Tweedy. — Furthur Observations on Welwitschia : Prof. H. H. W. 

 Pearson.— On the Presence of Ha;mo agglutinins, H«mo-opsonIns and 

 Ha:mo-lysins in the Blood obtained from Infectious and Non-Infectious 

 Diseases in Man (Preliminary' Communication) : L. S. Dudgeon._ — Pre- 

 liminary Note on the Occurrence of a New Variety of Trypanosomiasis in 

 the Island of Zanzibar ; A. Edington. 



Institution of Electrical Engineers, at 8. — Inaugural address by 

 the President. Mr. W. M. Mordey. 



.Mathematical Society, at 5.30 (Annual General !l{feling).—On the 

 Theory of Groups of Finite Order (Presidential Address) : Prof.W. Burn- 

 side. — On the Dirichlet Series and Asymptotic Expansion of Integral 

 Functions of Zero Order : J. E. Littlewood.— The Norm Curves on a Given 

 Base : Prof. F. Morley.— Satellite Curves on a Plane Cubic : J. 

 O'SuUivan.— On the Arithmetical Nature of the Coefficients in a Group of 

 Linear Substitutions (Third Paper) : Prof. W. Burnside. -On the Second 

 Mean Value Theorem of Integral Calculus : Dr. E. W. Hobson.-;-On the 

 Representation of a Function by Means of a Series of Legendre's Func- 

 tions : Dr. E. W. Hobson.— The Conformal Transformations of a Space 

 of Four Dimensions and their Applications to Geometrical Optics : H. 

 Bateman.— Periodic Properties of Partitions : D. M. Y. Sommerville.— 

 The Solution of Integral Equations: Prof. A. C. Dixon.— The Eliminant 

 of Three Quantics in Two Independent Variables: A. L Di.von -A Note 

 on the Continuity cr Discontinuity of a Function defined by an Infinite 

 Product: G. H. Hardy.— The Energy and Momentum of ,-in Ellipsoidal 

 Electron : F. B. Pidduck.-On 7-Integration : Rev. F. H. Jackson.— On 

 r;-Transformations of Power Series; Rev. F. H. Jackson.— The Complete 

 Solution in Integers of the Eulerian Equation X-1 -|- YJ = U J -I- \* : Dr. T. 



FRIDA Y, November 13. 

 Physical Society, at 8. 

 Malacological Society, at 8. — Note on D!plomniatinast}-ul'rUi, Smith: 



E. A. Smith.— The Radula of British Helicids, 'Part ii : Kev. E. W. 



Bowell.— New Marine Mollusca from New Caledonia, &c. : G. B. Sowerby. 



— New Species of Macrochlamys and Monocondylaea from Siam : H. B. 



Preston.— A New Species of Oliva : F. G. Bridgman. 



CONTENTS. 



By D. H. S. 

 C. G 



Alternation of Generations in Plants. 

 Windmills and Water-wheels. By C. 



Neurology 



Our Book Shelf:— 



Armi.stead : " Trout Waters : Management and 



Angling."— L. W. B . 



Edwardes : "The Lore of the IIoney-Bee." — 



F. W. L. Sladen 



Prescott and Winslow : "Elements of Water Bacteri- 

 ology, with Special Reference to Sanitary Water 



Analysis."— Prof. R. T. Hewlett 



Dutton : "The National Physique."— W. D. H, . . 

 Letters to the Editor: — 



Anomalous Dispersion of Luminous Hydrogen. 

 (///;M/r<3/trf.)— Rudolf Ladenburg andStanislaw 



L.oria 



The 479 Period of Sun-spot Activity.— Prof. Arthur 



Schuster, F.R.S . .... 



Memory in the Germ Plasm.— Dr. H. Charlton 



Bastian, F.R.S. ; G. Archdall Reid .... 



Polypus Vinegar— Sea-blubber Arrack. — Kumagusu 



Minakata 



Occurrence of a Fresh-water Nemertine in Ireland. 



— Rowland Southern .... 



Mercury Bubbles.— J. G. Ernest Wright .... 

 Some Cromlechs in North Wales. II. [Jl/iistra/ed.) 



By Sir Norman Lockyer, K.C.B., F.R.S 



Niagara as a Geological Chronometer. {Willi Map.) 



By Prof. J. W. Gregory, F.R.S 



The Nature and Charge of the a Particles from 

 Radio-active Substances. By Prof. E. Ruther- 

 ford, F.R.S 



Notes 



Our Astronomical Column : — 



The Spectrum of Comet Morehouse, igoSi 



Solar Vortices and their Magnetic Efifects 



The Wave-length of the H5 Line 



Meteoric Iron and Artificial Steel . . 



The Science Faculty of the University of London . 



Enteric Fever in India 



The Lime Tree and its Products . . 



Mathematics andPhysics at the British Association 



University and Educational Intelligence 



Societies and Academies 



Diary of Societies 



NO. 2036, VOL. 79] 



