24 



NATURE 



[November 3, 1892 



—Elements of the comet Barnard, of October 12, 1892, by M. L. 

 Schulhof.— On the algebraic intei>;rals of the differential equation 

 of the first order, by M, L. Autonne. — On centres of geodesic 

 curvature, by M. Th. Caronnet. — On Pfaffs probleaa, by 

 M. A. J. Stodolkievitz. — -Sunspots and magnetic disturbances in 

 1892, by M. Ricco, — On considerations of homogeneity in 

 physics ; reply to M. Clavenad, by M. Vaschy. — Verification of 

 parallelism of optic axes in uniaxial crystalline plates, by M. 

 Bernard Brunhes. — On a photoptometric photometer, for the 

 measurement of feeble illuminations, by M. Charles Henry. 

 This is based upon the constancy of the phosphorescent sulphide 

 of zinc. Its law of loss of brilliance being determined, it may 

 be used for measuring very feeble illuminations, such as distant 

 artificial light or the general luminosity of the sky due to the 

 stars. The decrease of light after the first 900 seconds being 

 given by i •*' {t — 18 '5) — const., it is easy to calculate the 

 luminosity at any instant. In the instrument in question there 

 are two screens of ground glass, one of which is illuminated by 

 the phosphorescent sulphide, brought to its maximum glow at 

 a certain time by burning magnesium ribbon, the other 

 exposed to the source of light. It is then only necessary 

 to wait till both the screens are equally illuminated, and 

 to note the time. — On the dissociation of chrome alum, 

 by MM. H. Baubigny and E. Pechard. — On the tempera- 

 tures of maximum density of aqueous solutions, by M. L. 

 de Coppet. — On some double salts of quinine, by M. E. 

 Grimaux.-^On the thermal value of the three functions of 

 orthophosphoric acid, and on its constitution, by M. de Forcrand. 

 — Preparation and properties of fibroine, by M. Leo Vignon. — • 

 Regeneration of the so-called sporangial form in the diatoms, 

 by M. P. Miquel. — On the hematozoaria of cold-blooded 

 vertebrates, by M. Alphonse Labbe. — Influence of coloured 

 light on the development of animals, by M. E. Yung. — On the 

 mode of fixation of the hexapod parasitic larvae of the acarians, 

 by M. S. Jourdain. — The cavern of Brassempouy, by M. Edouard 

 Piette. — Discovery of a sV^X^'io'a.oi Elephas nieridionalis\x\.\.\i& 

 basaltic ashes of the volcano of Seneze, by M. Marcellin Boule. 

 — Vegetable prints of the Dover boring, by M. R. Zeiller. 



Berlin. 

 Meteorological Society, October 11. — Prof, von Bezold, 

 president, in the chair. — Dr. Berson reported on an interesting 

 relationship which he had discovered between insolation and 

 temperature. Since it has not yet been possible to determine 

 accurately the absorption due to the atmosphere, the speaker 

 had calculated the insolation at the external limit of the atmo- 

 sphere, which admits of rigid mathematical treatment, both for 

 the whole year and for the months of January and July. The 

 mean of insolation for the whole year was found to lie at the 

 thirtieth degrees of northerly and southerly latitude, so that the 

 zone between these parallels, or about 60 per cent, of the whole 

 external surface, receives more insolation than the mean, whereas 

 the two polar caps, or the remaining 40 per cent., receive less. 

 A similar calculation of the annual temperature gave the mean 

 as at latitude 38° N. and 35° S., giving as before 60 per cent, of 

 the surface with the temperature above the mean, and 40 per cent. 

 below. In January 61 "35 per cent, of the surface experienced an 

 insolation above the mean and 60 per cent, a temperature above 

 the mean, while in July the percentages were respectively 61*37 

 and 6 1 '33. — Dr. Zenker gave a short account of a research on the 

 relationship between temperature and insolation on the earth's 

 surface. He had accurately calculated the relationship both for 

 regions comprising land only and water only, and arrived at 

 some interesting conclusions as to the theoretical temperatures 

 at various latitudes of continents and oceans. 



Physical Society, October 21. — Prof. Kundt, president, in 

 the chair. — Dr. Jager gave an account of the measurements he 

 had made, in conjunction with Dr. Kreischgauer, of the tem- 

 perature-coefficient of electric conductivity of mercury. Dr. 

 Arons demonstrated an arc-light between mercurial electrodes 

 in vacuo. It yielded a dazzling white light, which was steady 

 at the anode but flickered and jumped at the cathode : its 

 intensity approximated to that of an ordinary carbon arc- 

 light. The heat given off by it was but slight so that the tube 

 could be held in the hand ; the temperature was highest at the 

 cathode. Attempts were made to determine the resistance of 

 the arc, but without result. It was found by the use of a tele- 

 phone that the current is discontinuous. A spectroscopic 

 investigation of the light revealed a lime-spectrum showing very 



brilliantly a yellow, a green, and a blue line. In addition to 

 the ordinary lines due to mercury some twenty new lines were 

 observed. No satisfactory results were obtained by using 

 amalgams instead of mercury, with the one exception of 

 sodium-amalgam. It is proposed to make further experiments 

 with fluid amalgams of sodium and potassium. 



BOOKS and SERIALS RECEIVED. 



Books.— The Great World's Farm : S. Gaye (Seeley).— The Zoological 

 Record, 1891 (Gurney and Jackson).— Castorologia, or the History and 

 Traditions of the Canadian Beaver: H. T. Manin (Stanford).— Transac- 

 tions of the Royal Society of Edinburgh, vol. xxxvi. Parts 2 and 3 (Edin- 

 burgh).— Les Alpes Fran^aises : A. Falsan (Paris, Bailliere) —Calendar of 

 the University College of Wales. Aberystwith, 1892-93 (Manchester, 

 Cornish). — London Birds and other Sketches, revi.sed edition : T. D. Pigott 

 (Porter).— Contents and Index of the First Twenty Volumes of the Memoirs 

 of the Geological Survey of India, 1859-83 : W. Theobald (Calcutta).— 

 Memoirs of the Geological Survey of India ; Index to the Genera and 

 Species described in the Palseontologia Indica, up to the Year 1891 : W. 

 Theobald (Calcutta).— Star Atlas : Dr. H. J. Klein, translated. &c., by E. 

 McCliire, new edition (S. P.C.K.).— City and Guilds of London Institute 

 Programme of Technological Examinations, 1892-93 (London). — Appareils 

 d'Essai a froid et a chaud des Moteurs h Vapeur: M. Dudebout (Paris, 

 Gauttiier-Villars). —Canon Torpilles et Cuirasse : A. Croneau (Paris, 

 Gauthier-Villars). — Ostvvald's Klassiker der Kxakten Wissenschaften, Nos. 

 3137 (Leipzig, Engelmann).— Gesammelte Abhandlungen iiber Pflanzen- 

 Physiologie, Erster Band: J. Sachs (Leipzig, Engelmann).— On the 

 American Iron Trade and its Progress during Sixteen Years : Sir L. Bell 

 (Ballantyne).— Universal Atlas, Part 20 (Cassell). 



Serials.— The Physical Society of London, Proceedings, vol. xi. Part 4 

 (Taylirand Francis).— Botanical Gazette, October (Bloomington, Indiana). 

 — Trait6 Encyclop^dique de Photographie, Premier Suppl(5ment A. quat. 

 fasc. : C. Fabre (Paris, Gauthier-Villars).— Zeitschrift fiir Wissenschaftliche 

 Zoologie, liv. Band, 4 Heft (Williams and Norgate).— Morphologisches 

 Jahrbuch, xix. Band, i Heft (Williams and Norgate). 



CONTENTS. PAGE 



The University Commission i 



The Study of Animal Life. By C. LI. M 2 



Vector Algebra 3 



The Lake of Geneva. By Prof. T, G. Bonney, F.R.S. 5 

 Our Book Shelf :— 



Ward : " Horn Measurements and Weights of the 

 Great Game of the World, being a Record for the 



Use of Sportsmen and Naturalists " 6 



Philippson : " Der Peloponnes. Versuch einer Landes- 



kunde auf geologischer Grundlage " 6 



Fabre : " Traite Encyclopedique de Photographie." — 



W 6 



"The Reliquary": Quarterly Archaeological Journal 



and Review 7 



Letters to the Editor :— 



Nova Aurigse.— H. F. Newall 7 



Formation of Lunar Volcanoes. {Illustrated.)— 1. B, 



Hannay • 7 



On the Need of a New Geometrical Term — " Conju- 

 gate Angles."— Prof. A. M. Worthington . 8 



Printing Mathematics. — W. Cassie 8 



" Sunshine ."—Amy Johnson ; C. V. B 9 



The Photography of an Image by Reflection. — Frede- 

 rick J. Smith 10 



Induction and Deduction.— Edward T. Dixon . . . xo 

 Bell's Idea of a New Anatomy of the Brain. — ^Jas. B. 



Bailey • ■ ... 11 



Photographic Dry Plates.— Arthur E. Brown ... 11 

 The Genus Sphenophyllum. {With Diagram.) By 



Prof. Wm. Crawford Williamson, F.R.S il 



Dendritic Forms. By Sydney Lupton 13 



Notes H 



Our Astronomical Column: — 



Comet Brooks (August 28) ' . . . . 18 



Comet Barnard (October 12) 18 



Tabular History of Astronomy to the Year 1500 A. D . 18 



A Large Telescope '^ 



The Atmospheres of Planets 18 



Geographical Notes ^9 



The Institution of Mechanical Engineers J9 



International Committee of Weights and Measures 21 

 Notes on some Ancient Dyes. By Edward Schunck, 



F.R.S 22 



Scientific Serials 23 



Societies and Academies 23 



Books and Serials Received . 24 



NO. 1201, VOL. 47] 



