36o 



NATURE 



[February 13, 1896 



July 6. — On certain regularities in the spectra of solid bodies, 

 and on a new determination of the sun's temperature, by F. 

 Paschen. 



July 20. — Researches (ii.) from the Gottingen University 

 Laboratory : (i) On new instances of isomerism and abnormal 

 molecular refraction in certain cyclic ketones ; (2) on pulegon, 

 by O. Wallach. — Report on the scientific memoirs issued from 

 the Gottingen University Pathological Institute in the session 

 1894-95, by J. Orth. 



October 19. — (i) Contributions to the theory of algebraic 

 numbers ; (2) the unimodular substitutions in an algebraic 

 Zahlenkorper, by A. Hurwilz. — On a geometrical representation 

 of the ordinary development of a continued fraction, by Y. 

 Klein— On the regions of discontinuity of the groups of real 

 linear substitutions of a complex variable, by Robert Fricke. — 

 On the foundations of the theory of " ideals," by Ph. Furt- 

 wangler. 



November 2 (Commemoration-day). — On the " arithmetisa- 

 tion " of mathematics, by F. Klein. 



DIARY OF SOCIETIES. 



London. 



THURSDA V, February 13. 



Royal Society, at 4.30.— On the Behaviour of Argon and Helium when 

 submitted to the Electric Discharge : Dr. J. N. Collie and Prof. Ramsay, 

 F.R.S.— On the Generation of Longitudinal Waves in Ether: Lord 

 Kelvin, F.R.S.— On the Discharge of Electricity produced by the Rontgen 

 Rays, and the Effects produced by these Rays on Dielectrics through 

 which they pass : Prof. J. J. Thomson, F.R.S. 



Society of Arts, at 4.30.— Punjab Irrigation— Ancient and Modern : Sir 

 James Broadwood Lyall, G.C.LE., K.C.S.L 



Mathematical Society, at 8.— Geodesies on Quadrics, not of Revolution : 

 Prof. Forsyth, F.R.S.— Solid Ellipsoidal Vortex: R. Hargreaves.— 

 Potential of a Cyclide : A. L. Dixon. 



iRoyal Institution, at 3.— Some Aspects of Modern Botany : Prof. H. 

 Marshall Ward, F.R.S. 



Institution of Electrical Engineers, at 8.— The Electric Wiring 

 Question : F. Bathurst.— Concentric Wiring : Sam. Mavor. 



Society of Antiquaries, at 8.30. 



-Gresham College (Basinghall Street, E.C.), at 6.— The Planet Jupiter : 

 Rev. E. Ledger. 



FRIDA V, February 14. 

 >R0YAL Institution, at 9.— Fish Culture : J. J. Armistead. 



Physical Society, at 5.— Annual General Meeting.— On the Determina- 

 tion of High Temperatures with the Meldometer : W. Ramsay and N. 

 Eumorfopnilos. 



Royal Astronomical Society, at 3.— Annual Meeting. 

 -Institution of Civil Engineers, at 8.— The Construction of the Molong 

 to Forbes Railway, New South Wales : Sydney Thow. 



Malacological Society, at 8.— Annu,al Meeting. 



>fjRESHAM College, at 6.— The Planet Jupiter : Rev. E. Ledger. 



SUNDAY, February 16. 

 Sunday Lecture Society, at 4.— Water Skin : Douglas Carnegie. 



MONDAY, February 17. 

 Society of Arts, at 8.— The Chemistry of certain Metals and their Com- 

 pounds used in Buildings, and the Changes produced in them by Air, 

 Moisture, and Noxious Gases, &c.: Prof. J. M. Thompson. 

 Victoria Institute, at 4.30.— China : Dr. Gordon. 



TUESDA Y, February 18. 



Royal Institution, at 3.— External Covering of Plants and Animals ; 

 Prof C. Stewart. 



Society of Arts, at 8.— The Development of Electrical Traction Anna- 

 ratus ; H. F. Parshall. 



Zoological Society, at 8.— On the Butterflies obtained in Arabia and 

 Somaliland by Captain Chas. G. Nurse and Colonel J. W. Verbury in 

 1894-95 : Dr. Arthur G. Butler.— On Moths collected at Aden and in 

 SomahLind : Lord Walsingham, F.R.S., and G. F. Hampson.— Observa- 

 tions on the Metallic Colours of the Trochilidae and the Nectariniidse 

 (communicated by F. E. Beddard, F.R.S.) : Miss Marion Newbigin 

 .Institution of Civil Engineers, at 8.— The Manufacture of Aluminium 

 by Electrolysis ; and the Plant at Niagara for its Extraction : Alfred 

 Ephraim Hunt. 

 jRoyal Statistical Society, at 5.— Mental and Physical Conditions 

 among 50,000 Children seen 1892-94, and the Methods of Studying Re- 

 corded Observations, with special reference to the Determination of the 

 Causes of Mental Dulness and other Defects : Dr. Francis Warner. 

 "■Royal Photographic Society, at 8. 



Pathological Society, at 8.30. 



(Koyal Victoria Hall, at. 8.30.— Flowers and their Insect Visitors : Dr. 

 Kimmins. 



WEDNESDAY, February 19. 



Society of Arts, at 8.— Report of the Royal Commission on Secondary 

 Education : H. Macan. 



Royal Meteorological Society, at 7.30.— Report on the Phenological 

 Observations for 1895 : Edward Mawley, President.— Notes on the 

 Recent unusually High Barometer Readings in the British Isles : Robert 

 H. Scott, F.R.S. — Turner's Representations of Lightning : Richard 

 Inwards. 



Royal Microscopical Society, at 8. 



NO. 1372, VOL. 53] 



Entomological Society, at 8.— Notes on Flower-Haunting Diptera : 

 G. F. Scott-Elliot.— On the Nomenclature of the Geometridae : A. Rad- 

 cliffe-Grote. 



THURSDA Y, February 20. 



Royal Society, at 4.30.— Bakerian Lecture— The Diffusion of Metals : 

 Prof Roberts-Austen, F.R.S. 



Royal Institution, at 3. — Some Aspects of Modern Botany : Prof. 

 Marshall Ward, F.R.S. 



Linnean Society, at 8. — On Discoveries resulting from the Division of 

 a Prothallus of a Variety of Scolopendrium vulgare : E. J. Lowe, F.R.S. 



Chemical Society, at 8.— Origin of Colour: the Yellow 2:3 Hydroxy- 

 naphthoic Acid ; Note on Etherification ; The Relation of Pinene to 

 Citrene : Prof. Armstrong, F.R.S. 



London Institution, at 6.— My Voyage to Siberia : Captain Wiggins. 



Numismatic Society, at 7. 



Society of Antiquaries, at 8.30. 



FRIDAY, February 21. 

 Geological Society, at 3. — Annual General Meeting. 

 Royal Institution, at 9.— The Past, Present, and Future Water Supply 



of London: Dr. E. Frankland, F.R.S. 

 Institution of Civil Engineers, at 8. 

 Quekett Microscopical Club, at 8. 



SATURDAY, February 22. 

 Royal Institution, at 3.— Light : Lord Rayleigh, F.R.S. 

 Royal Botanic Society, at 3.45. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED 



Books. — Cocoa, all about it: " Historicus " (Low). — Links in a Long 

 Chain : Mrs. A. Bell (Philip). — Annuaire de I'Observatoire Municipal de 

 Montsouris, 1896 (Paris, Gauthier-Villars). — Cours de Physique de I'Kcole 

 Polytechnique : Prof. M. Bouty, premier supplement (Pans, Gauthier- 

 Villars). 



Pamphlets. — Atlas des Isanomales et des Variations Stfculaires du Mag- 

 n^tisme Terrestre : Lieut. -General A. de Tillo (St. Petersbourg).— Royal 

 Gardens, Kew : Hand-Li.st of Orchids cultivated in the Royal Gardens 

 (Eyre). • . , . 



Serials. — Scribner's Magazine, February (Low). — Transactions of the 

 English Arboricultural Society. Vol. 3, Part i (Carlisle). — Geological Maga- 

 zine, February (Dulau). — Engineering Magazine, February (Tucker). — 

 Massachusetts Institute of Technology, Boston, Annual Catalogue, 1895-96 

 (Cambridge, Mass.). — American Journal of Science, February (New Haven). 

 —Bulletin de I'Acad^mie Royale des Sciences, &c., de Belgique, Tome 30, 

 No. xii. (Bruxelles). — Proceedings of the Royal Society, Edinburgh, Session 

 1894-95, Vol. XX. pp. 481-546 (Edinburgh). — Bulletin of the American Mathe- 

 matical Society, January (New York, Macmillan). 



CONTENTS. PAGE 



Popular Geology. By Dr. Maria M. Ogilvie .... 337 



Primitive Picture-Writing 338 



Our Book Shelf:— 



Edwards: " Elements of Geometry " 339 



Stevens : " Elementary Mensuration " 339 



Clarke : " Mensuration " 339 



Weedon : " Physical Measurements " 340 



Letters to the Editor:— 



The New Actinic Rays. — Lord Blythswood ; A. A. 



C. Swinton ; Sydney D. Rowland 340 



" The Astronomical Theory of the Glacial Period." — 



Sir Henry H. Howorth, K.C.I.E., F.R.S. . . 340 

 The Positions of Retinal Images. ( With Diagram. ) — 



Mrs. C. Ladd Franklin 341 



The Story of Helium. II. {Illustrated.) By J. Norman 



Lockyer, C.B., F.R.S 342 



Science Teaching in Secondary Schools. By 



Charles M. Stuart 346 



Notes 348 



Our Astronomical Column: — 



The Astrophotographic Catalogue 351 



Orbit of o Centauri 351 



. Comets of Short Period 351 



Effect of Spots on Sun's Diameter 352 



The Speculative Method in Entomology. By Prof. 



R. Meldola, F.R.S 352 



University and Educational Intellige nee 356 



Scientific Serials 357 



Societies and Academies 357 



Diary of Societies 360 



Books, Pamphlets, and Serials Received 360 



