NATURJi 



[October 2 8,'IcS97 



is no publication which shows the corresponding value in Green- 

 wich mean time of the local time employed throughout the 

 world. Such a table is much wanted, and is indispensable in 

 order to determine the instant of occurrence of earthquakes, 

 magnetic phenomena, &c. — Sunless days and the day-distri- 

 bution of sunshine in summer. This is a discussion of twenty 

 years' observations at Greenwich (1877-96). About one-fourth 

 of our days are sunless. Spring has an average of 12T ; 

 summer, 6'4 ; autumn, 250; and winter, 485 sunless days. 

 The most " bright sunshine " occurs in May. During the five 

 months May to September, 20 per cent, of the days have less 

 than one hour's sunshine, while 14 per cent, have ten hours, or 

 more. There are only eight cases of fourteen to fifteen hours' 

 sunshine, and only one (in 1887) over fifteen hours. — Other 

 papers refer to "so-called sulphur rains," "trees damaged by 

 lightning," &c. 



SOCIETIES AND ACADEMIES. 



Manchester. 

 Literary and Philosophical Society, October 19. — Mr. 

 J. Cosmo Melvill, President, in the chair. — The death of Mr. 

 James Hey wood, F. R.S., the father of the Society, was an- 

 nounced, and a vote of condolence with the family was moved. 

 — Prof. H. B. Dixon described experiments made in photo- 



. graphing explosion-flames : first, attempts made abroad, and 



. afterwards experiments of his own. — Prof. F. E. Weiss exhibited 

 some flowering specimens of the Dog's Mercury, which usually 

 flowers in spring ; but the plant from which the shoots exhibited 

 were collected has been observed by Mr. F. J. George, of 



I Chorley, for thirteen successive seasons to flower in the autumn. 

 Sir Joseph Hooker, to whom some of these shoots had been 

 sent, was of the opinion that this plant might be regarded as a 

 special form with this autumn flowering character. — A paper by 

 Mr. P. Cameron, entitled " Notes on a collection of Hymenoptera 

 from Greymouth, New Zealand, with d^criptions of new 

 species," was communicated by the Ei^^dent. — Mr. Melvill 

 afterwards exhibited some specimens of Sisymbritiin strictis- 

 simwn, found by Mr. Henry Hyde oh the banks of the Mersey 

 at Stretford. 



Paris. 

 Academy of Sciences, October 18. — M. A. Chatin in the 

 chair. — On the observation and kinematical interpretation of 

 the phenomena discovered by Dr. Zeeman, by M. A. Cornu. 

 The phenomenon in question, the formation of doublets and 

 triplets in a spectrum by the action of external magnetic forces, 

 lis shown experimentally to be subject to the laws of Fresnel 

 and Ampere. It differs essentially from the Faraday efi"ect, in 

 that the latter is produced upon luminous waves that have 

 acquired a steady state, causing an alteration in the velocity of 

 propagation, whilst in the Zeeman effect the magnetic action is 

 exerted upon the source of the waves, and affects the period of 

 vibration. — An account of the International Geological Congress 

 ;at St. Petersburg, by M. Albert Gaudry. — On pencils and con- 

 jgruences, by M. Guichard. — Researches upon alcohol motors, 



I by M. Max. Ringelmann. Two sets of trials were made, one upon 

 a 3 h.p. horizontal, the other upon a 4 h.p. vertical oil engine. 

 As the result of the trials it was found that the cost of alcohol, 

 petroleum spirit, and ordinary burning oil were 5*625, 175 and 

 I'oo respectively. — On the form of the lines of electric force in 

 the neighbourhood of a Hertz resonator, by M. Gutton. The 

 field was explored by means of a modification of the receiver of 

 Prof. J. C. Bose. — Densities of some easily liquefiable gases, by 

 M. A Leduc. The gases examined were carbon dioxide 



.(i'5287), nitrous oxide (i"530i), hydrogen sulphide (11895), 

 chlorine (2 "491) and ammonia (o"597i). — On the impurities of 

 crude copper, by M. Schlagdenhauffen. Thin sheets of crude 

 Chilian copper, left in contact with water for several days, gave 

 up appreciable quantities of arsenious acid and oxide of antimony. 

 From this experiment the conclusion is drawn that arsenic and 

 antimony are present, at any rate in part, in the form of oxide in 

 crude copper. — On the electric conductivity of trichloracetic 

 acid, by M. Paul Rivals. Measurements of the conductivity and 

 heat of solution of trichloracetic acid at different concentrations 

 showed that the heat of dilution of this acid is a linear function 

 of the fraction of dissociation. The heat of neutralisation by 

 potash (N) calculated from Ostwald's formula, N = I3'52 + 

 (I - m)d, where I3"52 is a constant common to both strong 

 acids and strong bases, w is the fraction of dissociation, and ^the 



NO. 1461, VOL, 56] 



heat of dissociation, accorded very closely with the experi- 

 mentally determined values.— On the mean molecular weight of 

 the .soluble material in germinating grains, by M. L. Maquenne. 

 — General observations on oats, by M. Balland. An analytical 

 table is given, showing the maximum and minimum values of 

 the proximate constituents of oats. — New bile pigments, by MM, 

 A. Dastre and N. Floresco. — Action of the X-rays on the heat 

 radiated by the skin, by M. L Lecercle. Under the action of 

 the X-rays there is an increase in the radiation of heat from the 

 skin, an increase which frequently persists for some time after 

 the exposure. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Books.— The Founders of Geology : Sir A. Geikie (Macmillan).— Papers 

 printed to commemorate the Incorporation of the University College of 

 Sheffield : The Winter Meteorology of Egypt, and its Influence on 

 Disease : Dr. H. V.. L. Canney (Bailliire).— Chemistry for Photographers : 

 C. F. Town.send (Dawbarn).— Memorials of Wm. Cranch Bond and of his Son 

 Geo. Phillips Bond: E. S. Holden (San Francisco, Murdock).— Life-Histories 

 of American Insects: Prof. C. M. Weed (Macmillan).— Trac^ dun Chemin 

 de Fer : A. Dufour (Paris. Gauthier-Villars).— Theoretical Mechanics : 

 A. E H. Love (Cambridge University Press).— A Practical Physiology : Dr. 

 A. F. Blaisdell (Boston, Ginn).— Ostwald's Klassiker der Exakten Wissen- 

 schaften, Nrs. 88-91 (Leipzig, lingelmann).— Nights w.th an Old Gunner : 

 C. J. Cornish (Seeley).— Report of the Commissioner of Education for the 

 Year 1895-96, Vol. i, Part i (Washington).— La Vie Mode de Mouvement : 

 Prof. E. Preaubert (Paris, Alcan). — Wechselstrommessungen und Magiiet- 

 ische Messungen : Dr. C. Heinke (Leipzig. Hirzel).— Notes on Milto- 

 Organisms Pathogenic to Man : Surgeon-Captain B. H. S. Leumann 

 (Longmans). 



Pamphlets —Revision of the Tachinidae of America North of Mexico : 

 D W. Coquillett (Washington).— Zur Psychologic des Erkennens : Dr. G. 

 Wolff (Leipzig, Engelmann^. 



Sekials.— Physical Review, August (Macmillan) —Bibliotheca Geo- 

 graphica herausgegeben von der Gesellschaft fiir Erdkunde zu Berlin, 

 Band iii. Jahrg. 1894 (Berlin).— Revue de I'Universite' de Bruxelle.s, 

 October (Bruxelles).— Bulletin of the American Mathematical Society, 

 October (New York).— Traits Encyclop^dique de Photographic : Prof. C. 

 Fabre, deux supple'ment, B, r, 2, 3 fasc. (Paris, Gauthier-Villars).— Journal 

 of the Chemical Society, October (Gurney).— Quarterly Review, October 

 (Murray).— Middlesex Hospital Journal, No. 4 (London).— Reliquary and 

 Illustrated Archaeologist, new series. Vol. 3 (Bemrose).— Longman's Maga- 

 zine, November (Longmans). 



CONTENTS. PAGE 



The Logic of Darwin. By E. B. P 609 



A Theory of Physics 611 



Our Book Shell:- 



Noyes : " A Detailed Course of Qualitative Chemical 

 Analysis of Inorganic Substances, with Explanatory 



Notes" 61^ 



Deventer : " Physikalische Chemie fiir Anfanger" . . 6131. 

 Pike : " Bromide Enlargements, and How to Make 



them" 612 



Dolbear : "The Machinery of the Universe: 

 Mechanical Conceptions of Physical Phenomena" 6i2 

 Letters to the Editor: — 



On the Meaning of Symbols in Applied Algebra. — 



Prof. Oliver J. Lodge, F.R.S 613 



Strange Instinct of Fear in the Orang. — R. I. Pocock 613 

 Hereditary Colour in Horses. — F. Howard Collins 613 

 Dog Running on Two Legs. — F. M. Burton . . . 613 

 The Observation of Meteors, with Especial 



Reference to the Leonids. By W. F. Denning . 613 

 The Klondike Placers. By Dr. T. K. Rose .... 615 



Notes 616 



Our Astronomical Column : — 



Stars in the Large Magellanic Cloud 620 



The Photography of Delicate Celestial Phenomena . 620 



Comet Perrine, October 16 620 



Dr. B. Engelhardt's Observatory 620 



Science and Modern Civilisation. By Sir William 



Roberts, F.R.S 621 



The Behaviour of Argon in X-Ray Tubes. By 



Prof. H. L. Callendar, F.R.S., and N. N. Evans . 624 

 The Origin of the European Fauna. By Dr. R. F. 



Scharf 625 



Manchester's Report on Technical Education in 



Germany and Austria 627 



University and Educational Intelligence 630 



Scientific Serials 631 



Societies and Academies 632 



Books, Pamphlets, and Serials Received 632 



