24 



NA rURE 



[November 4, 1897 



" On the geodesic lines of surfaces of opposite curvatures," by 

 M. H. Poincare. — Observations on the new Perrine comet (1897, 

 October 16), made at the Observatory of Paris, by M. G. Bigour- 

 dan. — Observations of the same comet made at the Observatory 

 of Toulouse, by M. F. Rossard. — On the deformation of quadrics, 

 by M. C. Guichard. — On systems completely orthogonal in 

 space of n dimensions, and on the reduction of more general 

 differential systems, by M. Jules Drach.— On Weingarten 

 surfaces, by M. A. Pellet. — On a new method of reducing 

 the time of exposure in radiography, by M. Gaston Seguy. A 

 thin glass plate is coated on both sides with an emulsion of 

 gelatino-silver bromide, and allowed to dry. This is then en- 

 closed between two flexible screens, formed by M. Becquerel's 

 calcium violet in suspension in celluloid, and the whole pressed 

 together between cards. A photograph of the thorax, using a 

 six-inch coil, with thirty seconds' exposure, was completely 

 satisfactory, every detail being shown with great clearness. — On 

 a new bianodic bulb, with a red phosphorescence. The glass 

 of the bulb is tinged with didymium chloride. The fluorescence 

 is red instead of green, giving twice as much of the X-rays as 

 ordinary glass. The effects on the screen are very brilliant, 

 and can be seen by persons colour-blind to green. — 

 Researches on saline solutions ; lithium chloride, by M. Georges 

 Lemoine. Thermal data, showing the heat of dilution of solu- 

 tions of lithium chloride in water, methyl and ethyl alcohols. — 

 On some basic salts of magnesium, by M. Tassilly. The prepara- 

 tion and properties of the oxybromide MgBr2.3MgO. 12H2O 

 is described. — The separation and direct estimation of 

 chlorine and bromine in a mixture of alkaline salts, by MM. H. 

 Baubigny and P. Rivals. The separation is effected by potassium 

 permanganate in presence of a large excess of copper sulphate. 

 Analytical results are given, showing the trustworthiness of the 

 method under varying conditions. — On some combinations of 

 metallic acetates with phenylhydrazine, by M. J. Moitessier. 

 Double salts are formed with phenylhydrazine by the acetates of 

 ;zinc, cadmium, manganese, cobalt, and nickel.— The methods 

 of estimating diabetic sugar, by M. Frederic Landolph. A 

 Kjomparison of the results obtained in the estimation of 

 diabetic sugar by the polariscopic, fermentation, and copper 

 reduction methods, showed that only the optical can be 

 depended upon. — Optical and reducing power of the flesh 

 of flies, by the same. — Action of the X-rays upon the cuta- 

 neous evaporation, by M. L. Lecercle. In the rabbit, the 

 evaporation of a given portion of the skin can be almost com- 

 pletely suppressed, and the effects continue for some time after 

 the exposure. On the human hand, evaporation is somewhat 

 checked, but the action is fugitive, and the evaporation rapidly 

 recovers its original value. — On yellow fever, by M. le Dr. 

 Domingos Freire. A description of the habits and mode of 

 ^growth of the bacillus. Micrococcus xanthogenicus Attenuated 

 •cultures of this bacillus, injected into animals and man, produce 

 a mild form of yellow fever, which confers immunity from the 

 disease. Since 1883 some 13,000 persons have been inoculated, 

 of all ages and nationalities. The subsequent mortality from 

 yellow fever, in spite of violent epidemics which have raged, 

 ihas not exceeded six per thousand. — Observations on the circu- 

 lation of the Amphictenia, by M. Pierre Fauvel. — On the 

 ■differentiation and development of the woody elements, by M. L 

 Jules Leger. The discovery of a Miocene bat at Grive-Saint- 

 Alban, by M. Claude Gaillard. A complete humerus, and some 

 fragments were discovered. — On the Armand cave, by MM. 

 E. A. Martel and A. Vire. A description of the results of the 

 exploration of a subterranean cave, 207 metres deep, the most 

 remarkable feature being a forest of two hundred stalagmitic 

 columns, of heights varying between three and thirty metres. 



DIARY OF SOCIETIES. 



THURSDAY, November 4. 



LiNNEAN Society, at 8.— The Attraction of Flowers for Insects : Sir John 

 Lubbock, Bart. — Transfusion-Tissue: its Origin and Function in the 

 Leaves of Gymnospermous Plants : W. C. Worsdell. 



Chemical Society, at 8.— The Properties of Liquid Fluorine : Prof-. 

 Moissan and Dewar.— The Liquefaction of Air and the Detection of Im- 

 purities : Prof. Dewar.— The Absorption of Hydrogen by Palladium at 

 High Temperatures and Pressures : Prof. Dewar. 



Institution of Mechanical Engineers, at 7.3c.— Mechanical Features 

 of Electric Traction : Philip Dawson. 



FRIDA y, November 5. 



RoNTGEN Society, at 8.— Address by Prof. S. P. Thompson. 

 MOI\/DA V, November 8. 



Royal Geographical Society (Queen's Hall, Langham Place), at 8.45.— 

 Intioductory Address by the President.— The Jackson-Harmswcrth 

 Arctic Expedition : Frederick G. Jackson. 



TtTESpA V. November 9. 



Institution of Civil Engineers, at 8 — The Manchester Ship Canal ; 

 Sir E. Leader Williams. — The Mersey Estuary Embankments — Eastham 

 Division : Whately Kliot. — The Mer-^ey Estuary Embankments and o'her 

 Works — Runcorn Division : Sir E. Leader Williams. — The Irlam Divi- 

 sion : W. O. E. Meade-King. 



Anthropological Institute, at 8.30. — Works of Art from Benin City 

 C. H. Read and O. M. Dalton. 



Royal Photographic Society, at 8. — The Spectroscope : E. W. 

 Maunder. 



THURSDAY, November ii. 



Institution of Electrical Engineers, at 8. — Accumulator Traction on 

 Rails and Ordinary Roads : L. Epstein. 



Mathematical Society, at 8.— On the Poncelet Polygons of a Limaijon : 

 Prof. F. Morley. — On an Extension of the Exponential Theorem : J. IC. 



Campbell. — The Integral I 'P^^dx and Allied Forms in Legendre's 



Functions, between Arbitrary Limits: R. Hargreaves. — The Character of 

 the General Integral of Partial Differential Equations : Prof. Forsyth. 

 F.R.S. 



FRIDA y, November 12. 

 Royal Astronomical Society, at 8. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Books. — Light, Visible and Invisible : Prof. S. P. Thompson (Mac- 

 millan).— Chauncy Maples, D.D., F.R.G.S. (Longmans).— Cheltenham 

 as a Holiday Resort : S. S. Bunkman (Cheltenham, Norman). — Twentieth 

 Annual Report of the Local Government Board, 1895-96 : Supplement 



containing the Report of the Medical Officer for 1895-96 (Eyre). 



Die Wissenschaftlichen Grundlagen der Analytischen Chemie : W. 

 Ostwald, Zweite Vermehrte Auflage (Leipzig, Engelmann).— The Works of 

 Xenophon, transl.-ited by H G. Dakyns, Vol 3, Part 2 (Macmillan).— Hints 

 to Tea'.hers and Stuients on the Choice of Geographical Books for Refer- 

 ence and Reading, with Classified Lists : Dr. H. R. Mill (Longmans). 



Das Kleine Botanische Practicum fiir Anfanger : Dr. E. Strasburger, Dritte 

 Umgearbeiteie Auflage (Jena, Fischer).— A Geological Map of the Southerg 

 Transvaal : Dr. F. H. Hatch (Stanford).— Map of the Transvaal, showinn 

 Physical Features, &c. : Dr. F. H. Hatch (Stanford).— My Fourth Tour in 

 Western Australia: A. F. Calvert (Heinemann). 



Pamphlets.— A Popular Introduction to the Study of the Sun : G. M. 

 Knight (Philip).— Reforms needed in our System of Elementary Education • 

 T. C. Horsfall (Manchester, Cornish). 



Serials. — Chambers's Journal, November (Chambers) — The Record of 

 Technical and Secondary Education, October (Macmillan). — Natural 

 Science, November(Dent). — Mittheilungen der Pr.^historischen Commission 

 der Kais. Akademie der Wissenschaften, i Band, No. 4 (Wien). — Journal 

 of the Royal Microscopical Society, October (Williams).— Contemporary 

 Review, November (Isbister)— Good Words, November (Isbister).— Sunday 

 at Home, November (Isbister). — The Transactions of the Royal Irish Aca- 

 demy, Vol. xxxi. Part 4 (Dublin). — National Review, November (Arnold). — 

 Hum.anitarian, Novembe- (Hutchinson).— An Illustrated Manual of British 

 Birds : H. Sauiiders, 2nd edition, Part i (Gurney). 



PAGE 



NO. 1462. VOL. 57 J 



CONTENTS. 



Mimicry in Butterflies and Moths. By E. B. P. . . i 



A Devonshire Geologist. By H. B. W 4 



Mexican Archaeology 5 



Our Book Shelf: — 



Gabba : " Manuale del Chimico e dell' Industrial " . 7 

 Vender : " La Fabbricazione dell' Acido Solforico, dell' 

 Acido Nitrico, del Solfato Sodico, dell' Acido Muri- 



atico "..... 7 



Ghersi : " Leghe Metalliche ed Amalgame " .... 7 



Kimura : " Lectures on Quaternions." — ^J. P. ... 7 



Ule : " Lehrbuch der Erdkunde fiir hohere Schulen " . 7 



Denning : " The Great Meteoric Shower of November " 7 

 Letters to the Editor: — 



A Bee's Movements in a Room. — J. Parkin .... 8 



A Test for Divisibility. — Henry T. Burgess .... 8 



International Congress on Technical Education 9 

 Microscopic Study of Alloys. (Illustrated.) By T 



K. R '. . II 



Notes 12 



Our Astronomical Column: — 



The Photography of Faint Moving Celestial Objects . 16 



Sunspots and the Weather 16 



Comet Perrine, October 16 16 



The Director of the Lick Observatory 16 



Relation between Individual and Racial Variability 16 

 On the Constitution of the Electric Spark. By Prof. 



Arthur Schuster, F.R.S ... 17 



Physiology at the British Association 17 



On the Summit of Mauna Loa . . 20 



Palestine Exploration. By Lieut. -Colonel C. R. 



Conder 21 



University and Educational Intelligence 22 



Societies and Academics 23 



Diary of Societies 24 



Books, Pamphlets, and Serials Received 24 



